A Review of the Security of Insulin Pump Infusion Systems

PubMed Central

Paul, Nathanael; Kohno, Tadayoshi; Klonoff, David C

2011-01-01

Insulin therapy has enabled patients with diabetes to maintain blood glucose control to lead healthier lives. Today, rather than injecting insulin manually using syringes, a patient can use a device such as an insulin pump to deliver insulin programmatically. This allows for more granular insulin delivery while attaining blood glucose control. Insulin pump system features have increasingly benefited patients, but the complexity of the resulting system has grown in parallel. As a result, security breaches that can negatively affect patient health are now possible. Rather than focus on the security of a single device, we concentrate on protecting the security of the entire system. In this article, we describe the security issues as they pertain to an insulin pump system that includes an embedded system of components, which include the insulin pump, continuous glucose management system, blood glucose monitor, and other associated devices (e.g., a mobile phone or personal computer). We detail not only the growing wireless communication threat in each system component, but also describe additional threats to the system (e.g., availability and integrity). Our goal is to help create a trustworthy infusion pump system that will ultimately strengthen pump safety, and we describe mitigating solutions to address identified security issues. PMID:22226278

A review of the security of insulin pump infusion systems.

PubMed

Paul, Nathanael; Kohno, Tadayoshi; Klonoff, David C

2011-11-01

Insulin therapy has enabled patients with diabetes to maintain blood glucose control to lead healthier lives. Today, rather than injecting insulin manually using syringes, a patient can use a device such as an insulin pump to deliver insulin programmatically. This allows for more granular insulin delivery while attaining blood glucose control. Insulin pump system features have increasingly benefited patients, but the complexity of the resulting system has grown in parallel. As a result, security breaches that can negatively affect patient health are now possible. Rather than focus on the security of a single device, we concentrate on protecting the security of the entire system. In this article, we describe the security issues as they pertain to an insulin pump system that includes an embedded system of components, which include the insulin pump, continuous glucose management system, blood glucose monitor, and other associated devices (e.g., a mobile phone or personal computer). We detail not only the growing wireless communication threat in each system component, but also describe additional threats to the system (e.g., availability and integrity). Our goal is to help create a trustworthy infusion pump system that will ultimately strengthen pump safety, and we describe mitigating solutions to address identified security issues. © 2011 Diabetes Technology Society.

Pumping Insulin during Exercise: What Healthcare Providers and Diabetic Patients Need To Know.

ERIC Educational Resources Information Center

Colberg, Sheri R.; Walsh, John

2002-01-01

Exercise can decrease insulin resistance. Insulin pumps deliver precise insulin adjustments that improve fuel availability and provide glycemic control to help people with diabetes overcome obstacles to exercise. Physicians, patients, and healthcare providers should be familiar with the features and nuances of specific pump models and follow basic…

[The Elektronika UVI-01-N portable insulin pump (construction and method of use)].

PubMed

Sharikov, A N; Sklianik, A L

1990-01-01

The design and clinical applications of the first Soviet syringe portable insulin pump Electronica UV1 01 N are described. The technical characteristics and functional possibilities of the pump are discussed. The clinical results demonstrate good compensation for glucose metabolism by the insulin pump Electronica UV1 01 N.

Safety of the batteries and power units used in insulin pumps: A pilot cross-sectional study by the Association for the Study of Innovative Diabetes Treatment in Japan.

PubMed

Murata, Takashi; Nirengi, Shinsuke; Sakane, Naoki; Kuroda, Akio; Hirota, Yushi; Matsuhisa, Munehide; Namba, Mitsuyoshi; Kobayashi, Tetsuro

2017-10-21

We investigated the safety of the batteries and power units used in insulin pumps in Japan. A self-administered questionnaire was sent to the 201 members of the Association for Innovative Diabetes Treatment in Japan. A total of 56 members responded, and among the 1,499 active devices, 66 had episodes of trouble related to the batteries and power units. The ratio of reported troubles to the number of insulin pumps was significantly higher in insulin pumps with a continuous glucose monitoring sensor compared with insulin pumps without a continuous glucose monitoring sensor (odds ratio 2.82, P < 0.05). The cause and the consequences varied. The brands of the batteries varied; alkaline batteries purchased at drug stores and other shops accounted for 19.7%. Termination of battery life within 72 h of use was reported most frequently (50.0%), suspension of the insulin pump (21.2%) and leakage of the battery fluid (4.5%) followed. A total of 53.2% of the reported insulin pumps needed to be replaced, and 37.1% of them recovered after replacement of the battery. As trouble related to the batteries and power units of insulin pumps was frequent, practical guidance should be provided to respective patients regarding the use of reliable batteries, and to be well prepared for unexpected insulin pump failure. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

[Insulin pump therapy in children, adolescents and adults].

PubMed

Stadler, Marietta; Zlamal-Fortunat, Sandra; Schütz-Fuhrmann, Ingrid; Rami-Merhar, Birgit; Fröhlich-Reiterer, Elke; Hofer, Sabine; Mader, Julia; Resl, Michael; Kautzky-Willer, Alexandra; Weitgasser, Raimund; Prager, Rudolf; Bischof, Martin

2016-04-01

This position statement is based on the current evidence available on the safety and benefits of continuous subcutaneous insulin pump therapy (CSII) in diabetes with an emphasis on the effects of CSII on glycemic control, hypoglycaemia rates, occurrence of ketoacidosis, quality of life and the use of insulin pump therapy in pregnancy. The current article represents the recommendations of the Austrian Diabetes Association for the clinical praxis of insulin pump treatment in children, adolescents and adults.

New technology, new errors: how to prime an upgrade of an insulin infusion pump.

PubMed

Rule, Ann M; Drincic, Andjela; Galt, Kimberly A

2007-03-01

A series of use errors occurred when switching an ambulatory care clinic patient from an older model to a newer model of an ambulatory continuous subcutaneous insulin infusion pump. The nurse practitioner (N.P.) reviewed the new pump's mechanics with the patient, who had a 26-year history of Type 1 diabetes mellitus, and supervised the patient's programming of the pump. At bedtime, a blood sugar of > 250 mg/dL prompted the patient to give herself insulin via the pump. The next morning, she was treated at the emergency department for diabetic ketoacidosis. The pump had been improperly primed, resulting in no insulin delivery. The incident also reflected the absence of a fail-safe mechanism(s) on the pump to alert the user to the improper priming and inappropriate handoff of the patient's care. Unlike the old pump, the new pump did not require manual priming. The lack of delivery of insulin resulted in DKA, a potentially life-threatening complication of diabetes. A root cause analysis suggested several important safety issues, including skipping of steps on the patient training checklist and other shortcuts in patient training. The clinic developed policies and procedures, including mandatory formal training for each pump model by the certified pump trainer and for initiation of insulin pump therapy. This case illustrates the importance of a structured device selection process, provider education, patient education, and monitoring for safety and effectiveness of technological devices in care.

The role of insulin pump therapy for type 2 diabetes mellitus.

PubMed

Landau, Zohar; Raz, Itamar; Wainstein, Julio; Bar-Dayan, Yosefa; Cahn, Avivit

2017-01-01

Many patients with type 2 diabetes fail to achieve adequate glucose control despite escalation of treatment and combinations of multiple therapies including insulin. Patients with long-standing type 2 diabetes often suffer from the combination of severe insulin deficiency in addition to insulin resistance, thereby requiring high doses of insulin delivered in multiple injections to attain adequate glycemic control. Insulin-pump therapy was first introduced in the 1970s as an approach to mimic physiological insulin delivery and attain normal glucose in patients with type 1 diabetes. The recent years have seen an increase in the use of this technology for patients with type 2 diabetes. This article summarizes the clinical studies evaluating insulin pump use in patients with type 2 diabetes and discusses the benefits and shortcomings of pump therapy in this population. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Insulin Infusion Set: The Achilles Heel of Continuous Subcutaneous Insulin Infusion

PubMed Central

Heinemann, Lutz; Krinelke, Lars

2012-01-01

Continuous subcutaneous insulin infusion from an insulin pump depends on reliable transfer of the pumped insulin to the subcutaneous insulin depot by means of an insulin infusion set (IIS). Despite their widespread use, the published knowledge about IISs and related issues regarding the impact of placement and wear time on insulin absorption/insulin action is relatively small. We also have to acknowledge that our knowledge is limited with regard to how often patients encounter issues with IISs. Reading pump wearer blogs, for instance, suggests that these are a frequent source of trouble. There are no prospective clinical studies available on current IIS and insulin formulations that provide representative data on the type and frequency of issues with infusion sets. The introduction of new IISs and patch pumps may foster a reassessment of available products and of patient problems related to their use. The aim of this review is to summarize the current knowledge and recommendations about IISs and to highlight potential directions of IIS development in order to make insulin absorption safer and more efficient. PMID:22920824

Impact of insulin pumps on glycaemic control in a pump-naïve paediatric regional population.

PubMed

de Bock, Martin; Gunn, Alistair Jan; Holt, Jean-Ann; Derraik, José G B; Reed, Peter; Cutfield, Wayne; Mouat, Fran; Hofman, Paul; Jefferies, Craig

2012-03-01

To examine the clinical impact of insulin-pump therapy for children with type 1 diabetes mellitus (T1DM) in a regional paediatric service, Auckland, New Zealand. Retrospective analysis of children with T1DM from the Starship paediatric diabetes database who started on insulin-pump therapy from 2002 to 2008 compared with the whole T1DM population and with an equal number of non-pump patients matched by age, sex, ethnicity and duration of diabetes. From 621 subjects with 6680 clinic visits, 75 children were treated with insulin-pump therapy for more than 12 months. Transitioning to insulin-pump treatment was associated with an improvement in HbA1c compared with baseline (-0.3%/year, P < 0.001) for up to 3 years. In contrast, despite similar deprivation scores, non-pump controls showed a continuing trend to higher HbA1C values (+0.2%/year, P < 0.01). The risk of severe hypoglycaemia fell after pump start (from 27 (0-223) to 5 (0-0.91) events/100 patient years) with no change in non-pump controls; the rate of diabetic ketoacidosis remained low in both groups. In a pump-naïve regional paediatric population, insulin-pump therapy for T1DM was safe and effective, and associated with sustained improvements in HbA1c and lower risk of hypoglycaemia. © 2011 The Authors. Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Adherence to Insulin Pump Behaviors in Young Children With Type 1 Diabetes Mellitus.

PubMed

Patton, Susana R; Driscoll, Kimberly A; Clements, Mark A

2017-01-01

Parents of young children are responsible for daily type 1 diabetes (T1DM) cares including insulin bolusing. For optimal insulin pump management, parents should enter a blood glucose result (SMBG) and a carbohydrate estimate (if food will be consumed) into the bolus advisor in their child's pump to assist in delivering the recommended insulin bolus. Previously, pump adherence behaviors were described in adolescents; we describe these behaviors in a sample of young children. Pump data covering between 14-30 consecutive days were obtained for 116 children. Assessed adherence to essential pump adherence behaviors (eg, SMBG, carbohydrate entry, and insulin use) and adherence to 3 Wizard/Bolus Advisor steps: SMBG-carbohydrate entry-insulin bolus delivered. Parents completed SMBG ≥4 times on 99% of days, bolused insulin ≥3 times on 95% of days, and entered carbohydrates ≥3 times on 93% of days, but they corrected for hyperglycemia (≥250 mg/dl or 13.9 mmol/l) only 63% of the time. Parents completed Wizard/Bolus Advisor steps (SMBG, carbohydrate entry, insulin bolus) within 30 minutes for 43% of boluses. Inverse correlations were found between children's mean daily glucose and the percentage of days with ≥4 SMBG and ≥3 carbohydrate entries as well as the percentage of boluses where all Wizard/Bolus Advisor steps were completed. Parents of young children adhered to individual pump behaviors, but showed some variability in their adherence to Wizard/Bolus Advisor steps. Parents showed low adherence to recommendations to correct for hyperglycemia. Like adolescents, targeting pump behaviors in young children may have the potential to optimize glycemic control.

Assessment of use of specific features of subcutaneous insulin infusion systems and their relationship to metabolic control in patients with type 1 diabetes.

PubMed

Quirós, Carmen; Patrascioiu, Ioana; Giménez, Marga; Vinagre, Irene; Vidal, Mercè; Jansà, Margarita; Conget, Ignacio

2014-01-01

Patients with type 1 diabetes (T1DM) treated with continuous subcutaneous insulin infusion (CSII) have available several specific features of these devices. The aim of this study was to evaluate the relationship between real use of them and the degree of glycemic control in patients using this therapy. Forty-four T1DM patients on CSII therapy with or without real-time continuous glucose monitoring (CGM) were included. Data from 14 consecutive days were retrospectively collected using the therapy management software CareLink Personal/Pro(®) and HbA1c measurement performed at that period. The relationship between the frequency of usie of specific features of insulin pumps (non-sensor augmented or sensor-augmented) and glycemic control was analyzed. Mean HbA1c in the group was 7.5 ± .8%. Mean daily number of boluses administered was 5.1 ± 1.8, with 75.4% of them being bolus wizards (BW). Daily number of boluses was significantly greater in patients with HbA1c <7.5% than in those with HbA1c>7.5% (5.3 ± 1.6 vs. 4.3 ± 1.6, P=.056). There was a trend to greater use of BW in patients with better control (82.8 ± 21.4% vs. 69.9 ± 29.1%, P=.106). HbA1c was lower in patients using CGM (n=8) as compared to those not using sensor-augmented pumps (7.6 ± .8 vs 7.1 ± .7, P=.067), but the difference was not statistically significant. More frequent use of BW appears to be associated to better metabolic control in patients with T1DM using pump therapy. In standard clinical practice, augmentation of insulin pump with CGM may be associated to improved glycemic control. Copyright © 2013 SEEN. Published by Elsevier Espana. All rights reserved.

Economic benefits of improved insulin stability in insulin pumps.

PubMed

Weiss, Richard C; van Amerongen, Derek; Bazalo, Gary; Aagren, Mark; Bouchard, Jonathan R

2011-05-01

Insulin pump users discard unused medication and infusion sets according to labeling and manufacturer's instructions. The stability labeling for insulin aspart (rDNA origin] (Novolog) was increased from two days to six. The associated savings was modeled from the perspective of a hypothetical one-million member health plan and the total United States population. The discarded insulin volume and the number of infusion sets used under a two-day stability scenario versus six were modeled. A mix of insulin pumps of various reservoir capacities with a range of daily insulin dosages was used. Average daily insulin dose was 65 units ranging from 10 to 150 units. Costs of discarded insulin aspart [rDNA origin] were calculated using WAC (Average Wholesale Price minus 16.67%). The cost of pump supplies was computed for the two-day scenario assuming a complete infusion set change, including reservoirs, every two days. Under the six-day scenario complete infusion sets were discarded every six days while cannulas at the insertion site were changed midway between complete changes. AWP of least expensive supplies was used to compute their costs. For the hypothetical health plan (1,182 pump users) the annual reduction in discarded insulin volume between scenarios was 19.8 million units. The corresponding cost reduction for the plan due to drug and supply savings was $3.4 million. From the U.S. population perspective, savings of over $1 billion were estimated. Using insulin that is stable for six days in pump reservoirs can yield substantial savings to health plans and other payers, including patients.

Use of insulin pumps in India: suggested guidelines based on experience and cultural differences.

PubMed

Kesavadev, Jothydev; Das, Ashok Kumar; Unnikrishnan, Ranjit; Joshi, Shashank R; Ramachandran, Ambady; Shamsudeen, Jisha; Krishnan, Gopika; Jothydev, Sunitha; Mohan, Viswanathan

2010-10-01

All type 1 diabetes mellitus (T1DM) subjects and the majority of type 2 diabetes mellitus (T2DM) subjects at one time or another require insulin to sustain life. Syringes and pens are presently the most popular insulin delivery devices. Though in use for more than 3 decades, insulin pumps are now being more commonly used because of their unique ability to continuously infuse insulin, closely mimicking that of physiological secretion from a normal pancreas. Unlike insulin shots with syringes, pump infusion sites need to be changed less frequently. Scientific evidence from published studies have proven added benefit of insulin pumps in improving quality of life, normalizing sugars in recalcitrant diabetes, improving sexual function, and relieving the intractable pain of neuropathy. In the western world, pumps are commonly used with T1DM subjects, whereas in India 80% of pumpers are T2DM subjects. The success of insulin pump therapy depends on selection of the right candidate, extensive education, motivation, and implementing the sophisticated programs with skill. However, all affordable patients are not ideal candidates for pump therapy because for successful continuation of pump therapy other inclusion criteria should also be fulfilled. Among the other indications discussed are a high level of insulin resistance, brittle diabetes, chronic kidney disease on renal replacement therapy, and continuous glucose monitoring pattern strongly suggesting need for a variable basal insulin infusion rate. In International Diabetes Foundation data released in 2009, estimated diabetes prevalence for 2010 is 285 million, representing 6.4% of the world's adult population, with a prediction that by 2030 the number of people with diabetes will have increased to 438 million. Considering this massive growth in T2DM and its propensity after 10–15 years to lead to an insulin-deficient state, available evidence from studies is a compelling indication not to deny the benefits of continuous subcutaneous insulin infusion in selected T2DM subjects. This article aims at suggesting guidelines based on clinical experience and cultural diversity for India and developing countries.

Use of Insulin Pumps in India: Suggested Guidelines Based on Experience and Cultural Differences

PubMed Central

Das, Ashok Kumar; Unnikrishnan, Ranjit; Joshi, Shashank R.; Ramachandran, Ambady; Shamsudeen, Jisha; Krishnan, Gopika; Jothydev, Sunitha; Mohan, Viswanathan

2010-01-01

Abstract All type 1 diabetes mellitus (T1DM) subjects and the majority of type 2 diabetes mellitus (T2DM) subjects at one time or another require insulin to sustain life. Syringes and pens are presently the most popular insulin delivery devices. Though in use for more than 3 decades, insulin pumps are now being more commonly used because of their unique ability to continuously infuse insulin, closely mimicking that of physiological secretion from a normal pancreas. Unlike insulin shots with syringes, pump infusion sites need to be changed less frequently. Scientific evidence from published studies have proven added benefit of insulin pumps in improving quality of life, normalizing sugars in recalcitrant diabetes, improving sexual function, and relieving the intractable pain of neuropathy. In the western world, pumps are commonly used with T1DM subjects, whereas in India 80% of pumpers are T2DM subjects. The success of insulin pump therapy depends on selection of the right candidate, extensive education, motivation, and implementing the sophisticated programs with skill. However, all affordable patients are not ideal candidates for pump therapy because for successful continuation of pump therapy other inclusion criteria should also be fulfilled. Among the other indications discussed are a high level of insulin resistance, brittle diabetes, chronic kidney disease on renal replacement therapy, and continuous glucose monitoring pattern strongly suggesting need for a variable basal insulin infusion rate. In International Diabetes Foundation data released in 2009, estimated diabetes prevalence for 2010 is 285 million, representing 6.4% of the world's adult population, with a prediction that by 2030 the number of people with diabetes will have increased to 438 million. Considering this massive growth in T2DM and its propensity after 10–15 years to lead to an insulin-deficient state, available evidence from studies is a compelling indication not to deny the benefits of continuous subcutaneous insulin infusion in selected T2DM subjects. This article aims at suggesting guidelines based on clinical experience and cultural diversity for India and developing countries. PMID:20807118

A Retrospective Review of the Clinical Characteristics and Blood Glucose Data from Cellnovo System Users using Data Collected from the Cellnovo Online Platform.

PubMed

Hautier-Suply, Olivia; Friedmann, Yasmin; Shapley, Julian

2018-04-01

Technological advances have led to innovative insulin delivery systems for patients with type 1 diabetes mellitus. In particular, the combination of miniature engineering and software algorithms contained in continuous subcutaneous insulin infusion (CSII) system pumps provide the user and the healthcare practitioner with an opportunity to review and adjust blood glucose (BG) levels according to system feedback, and to modify or programme their regimen according to their needs. While CSII pumps record a number of data parameters such as BG level, carbohydrate intake, activity and insulin delivered, these data are generally 'locked in' and can only be accessed by uploading to a cloud-based system, thus information is not contemporaneous. The Cellnovo Diabetes Management System (Cellnovo, Bridgend, UK) allows data to be transmitted securely and wirelessly in real time to a secure server, which is then retrieved by an online platform, the Cellnovo Online platform, enabling continuous access by the user and by clinicians. In this article, the authors describe a retrospective review of the patient data automatically uploaded to the Cellnovo Online platform. Baseline clinical and demographic characteristics collected at the start of pump therapy are shown for all patients, and BG data from a sub-cohort of patients who have been using the system for at least 6 months and who take and record an average of three BG level tests per day are presented to demonstrate glycaemic data over time.

Fault Detection and Safety in Closed-Loop Artificial Pancreas Systems

PubMed Central

2014-01-01

Continuous subcutaneous insulin infusion pumps and continuous glucose monitors enable individuals with type 1 diabetes to achieve tighter blood glucose control and are critical components in a closed-loop artificial pancreas. Insulin infusion sets can fail and continuous glucose monitor sensor signals can suffer from a variety of anomalies, including signal dropout and pressure-induced sensor attenuations. In addition to hardware-based failures, software and human-induced errors can cause safety-related problems. Techniques for fault detection, safety analyses, and remote monitoring techniques that have been applied in other industries and applications, such as chemical process plants and commercial aircraft, are discussed and placed in the context of a closed-loop artificial pancreas. PMID:25049365

Evaluating the automated blood glucose pattern detection and case-retrieval modules of the 4 Diabetes Support System.

PubMed

Schwartz, Frank L; Vernier, Stanley J; Shubrook, Jay H; Marling, Cynthia R

2010-11-01

We have developed a prototypical case-based reasoning system to enhance management of patients with type 1 diabetes mellitus (T1DM). The system is capable of automatically analyzing large volumes of life events, self-monitoring of blood glucose readings, continuous glucose monitoring system results, and insulin pump data to detect clinical problems. In a preliminary study, manual entry of large volumes of life-event and other data was too burdensome for patients. In this study, life-event and pump data collection were automated, and then the system was reevaluated. Twenty-three adult T1DM patients on insulin pumps completed the five-week study. A usual daily schedule was entered into the database, and patients were only required to upload their insulin pump data to Medtronic's CareLink® Web site weekly. Situation assessment routines were run weekly for each participant to detect possible problems, and once the trial was completed, the case-retrieval module was tested. Using the situation assessment routines previously developed, the system found 295 possible problems. The enhanced system detected only 2.6 problems per patient per week compared to 4.9 problems per patient per week in the preliminary study (p=.017). Problems detected by the system were correctly identified in 97.9% of the cases, and 96.1% of these were clinically useful. With less life-event data, the system is unable to detect certain clinical problems and detects fewer problems overall. Additional work is needed to provide device/software interfaces that allow patients to provide this data quickly and conveniently. © 2010 Diabetes Technology Society.

Characterization of Exercise and Alcohol Self-Management Behaviors of Type 1 Diabetes Patients on Insulin Pump Therapy.

PubMed

Grando, Maria Adela; Groat, Danielle; Soni, Hiral; Boyle, Mary; Bailey, Marilyn; Thompson, Bithika; Cook, Curtiss B

2017-03-01

There is a lack of systematic ways to analyze how diabetes patients use their insulin pumps to self-manage blood glucose to compensate for alcohol ingestion and exercise. The objective was to analyze "real-life" insulin dosing decisions occurring in conjunction with alcohol intake and exercise among patients using insulin pumps. We recruited adult type 1 diabetes (T1D) patients on insulin pump therapy. Participants were asked to maintain their daily routines, including those related to exercising and consuming alcohol, and keep a 30-day journal on exercise performed and alcohol consumed. Thirty days of insulin pump data were downloaded. Participants' actual insulin dosing behaviors were compared against their self-reported behaviors in the setting of exercise and alcohol. Nineteen T1D patients were recruited and over 4000 interactions with the insulin pump were analyzed. The analysis exposed variability in how subjects perceived the effects of exercise/alcohol on their blood glucose, inconsistencies between self-reported and observed behaviors, and higher rates of blood glucose control behaviors for exercise versus alcohol. Compensation techniques and perceptions on how exercise and alcohol affect their blood glucose levels vary between patients. Improved individualized educational techniques that take into consideration a patient's unique life style are needed to help patients effectively apply alcohol and exercise compensation techniques.

Effect of sensor-augmented insulin pump therapy and automated insulin suspension vs standard insulin pump therapy on hypoglycemia in patients with type 1 diabetes: a randomized clinical trial.

PubMed

Ly, Trang T; Nicholas, Jennifer A; Retterath, Adam; Lim, Ee Mun; Davis, Elizabeth A; Jones, Timothy W

2013-09-25

Hypoglycemia is a critical obstacle to the care of patients with type 1 diabetes. Sensor-augmented insulin pump with automated low-glucose insulin suspension has the potential to reduce the incidence of major hypoglycemic events. To determine the incidence of severe and moderate hypoglycemia with sensor-augmented pump with low-glucose suspension compared with standard insulin pump therapy. A randomized clinical trial involving 95 patients with type 1 diabetes, recruited from December 2009 to January 2012 in Australia. Patients were randomized to insulin pump only or automated insulin suspension for 6 months. The primary outcome was the combined incidence of severe (hypoglycemic seizure or coma) and moderate hypoglycemia (an event requiring assistance for treatment). In a subgroup, counterregulatory hormone responses to hypoglycemia were assessed using the hypoglycemic clamp technique. Of the 95 patients randomized, 49 were assigned to the standard-pump (pump-only) therapy and 46 to the low-glucose suspension group. The mean (SD) age was 18.6 (11.8) years; duration of diabetes, 11.0 (8.9) years; and duration of pump therapy, 4.1 (3.4) years. The baseline rate of severe and moderate hypoglycemic events in the pump-only group was 20.7 vs 129.6 events per 100 patient months in the low-glucose suspension group. After 6 months of treatment, the event rates decreased from 28 to 16 in the pump-only group vs 175 to 35 in the low-glucose suspension group. The adjusted incidence rate per 100 patient-months was 34.2 (95% CI, 22.0-53.3) for the pump-only group vs 9.5 (95% CI, 5.2-17.4) for the low-glucose suspension group. The incidence rate ratio was 3.6 (95% CI, 1.7-7.5; P <.001). There was no change in glycated hemoglobin in either group: mean, 7.4 (95% CI, 7.2-7.6) to 7.4 (95% CI, 7.2-7.7) in the pump-only group vs mean, 7.6 (95%, CI, 7.4-7.9) to 7.5 (95% CI, 7.3-7.7) in the low-glucose suspension group. Counterregulatory hormone responses to hypoglycemia were not changed. There were no episodes of diabetic ketoacidosis or hyperglycemia with ketosis. Sensor-augmented pump therapy with automated insulin suspension reduced the combined rate of severe and moderate hypoglycemia in patients with type 1 diabetes. anzctr.org.au Identifier: ACTRN12610000024044.

An Overview of Insulin Pumps and Glucose Sensors for the Generalist

PubMed Central

McAdams, Brooke H.; Rizvi, Ali A.

2016-01-01

Continuous subcutaneous insulin, or the insulin pump, has gained popularity and sophistication as a near-physiologic programmable method of insulin delivery that is flexible and lifestyle-friendly. The introduction of continuous monitoring with glucose sensors provides unprecedented access to, and prediction of, a patient’s blood glucose levels. Efforts are underway to integrate the two technologies, from “sensor-augmented” and “sensor-driven” pumps to a fully-automated and independent sensing-and-delivery system. Implantable pumps and an early-phase “bionic pancreas” are also in active development. Fine-tuned “pancreas replacement” promises to be one of the many avenues that offers hope for individuals suffering from diabetes. Although endocrinologists and diabetes specialists will continue to maintain expertise in this field, it behooves the primary care physician to have a working knowledge of insulin pumps and sensors to ensure optimal clinical care and decision-making for their patients. PMID:26742082

Does Reducing Basal Insulin During Ramadan Fasting by Children and Adolescents with Type 1 Diabetes Decrease the Risk of Symptomatic Hypoglycemia?

PubMed

Deeb, Asma; Al Qahtani, Nabras; Attia, Salima; Al Suwaidi, Hana; Nagelkerke, Nico

2016-09-01

Ramadan fasting by patients with type 1 diabetes might predispose them to hypoglycemia. There are no data on the optimal way of adjusting basal insulin during fasting. We aim at studying whether reducing basal insulin during Ramadan reduces the frequency of symptomatic hypoglycemia. We enrolled children and adolescents with type 1 diabetes who intended to fast during Ramadan. Logbooks were given to subjects to mark days fasted, symptomatic hypoglycemia, and dose of basal insulin on all days of Ramadan. Logbooks were examined. Glucometers and insulin pumps were downloaded. Seventy-five patients were enrolled. The age was 10.2-18.9 (14.5) years. Sixty-eight patients had results analyzed. Forty-one patients were on pumps, and 27 patients were on multiple daily injections (MDI). Mean HbA1c was 7.9 (1.2) and 8.4 (1.3) for the pump and the MDI, respectively (P = 0.007). Thirty-nine patients had hypoglycemia leading to breaking fast. The mean number of episodes of breaking fast was 3 (1-8). Thirty-five of the 68 patients had reduced basal insulin. The difference in the frequency of hypoglycemia in those who reduced/did not reduce insulin was not statistically significant (P > 0.10). Fifteen patients on MDI and 24 patients on pumps had at least one episode of breaking fast. Six and 18 of the patients on MDI and pumps, respectively, reduced basal insulin (P > 0.10). This is the first study examining the impact of reduction of basal insulin on hypoglycemia in adolescents. Reducing basal insulin during Ramadan fasting does not decrease the risk of symptomatic hypoglycemia. Use of the insulin pump does not appear to be different from MDI in the frequency of occurrence of hypoglycemia.

Insulin pump use compared with intravenous insulin during labour and delivery: the INSPIRED observational cohort study.

PubMed

Drever, E; Tomlinson, G; Bai, A D; Feig, D S

2016-09-01

To assess the safety and efficacy of pump therapy (continuous subcutaneous insulin infusion; CSII) during labour and delivery in women with Type 1 diabetes. A retrospective cohort study of 161 consecutive Type 1 diabetic pregnancies delivered during 2000-2010 at Mount Sinai Hospital, Toronto, Canada. Capillary blood glucose levels during labour and delivery and time in/out of target (target: 4-6 mmol/l) were compared along with neonatal outcomes for three groups: (1) women on pumps who stayed on pumps during labour (pump/pump n = 31), (2) women on pumps who switched to intravenous (IV) insulin infusion during labour (pump/IVn = 25), and (3) women on multiple daily injections who switched to IV insulin infusion during labour (MDIn = 105). There were no significant differences between the mean or median glucose values during labour and delivery across all three groups, and no significant difference in time spent hypoglycaemic. However, women in the pump/pump group had significantly better glycaemic control as defined by mean glucose (5.5 vs. 6.4 mmol/l; P = 0.01), median glucose (5.4 vs. 6.3 mmol/l; P = 0.02), and more time spent in target (60.9% vs. 39.2%; P = 0.06) compared with women in the pump/IV group (after removing one outlier). This study demonstrates that the continuation of CSII therapy during labour and delivery appears safe and efficacious. Moreover, women who choose to continue CSII have better glucose control during delivery than those who switch to IV insulin, suggesting that it should be standard practice to allow women the option of continuing CSII during labour and delivery. © 2016 Diabetes UK.

[The use of continuous subcutaneous insulin infusion (CSII) with personal insulin pumps in the treatment of children and adolescents with diabetes type 1].

PubMed

Jarosz-Chobot, Przemysława

2004-01-01

This paper sums up recently published researches on the continuous subcutaneous insulin infusion (CSII) with the use of insulin pump in children and adolescents with diabetes type 1. Obtaining a balance in the organism metabolism in childhood and adolescence diabetology is nowadays one of the most important rules of the diabetes management in children. One of the modern ways to achieve that goal is the intensive insulin therapy model with use of the insulin pump. In this paper the advantages and disadvantages as well as the indications and contraindications for the CSII in children and adolescents with diabetes are widely discussed.

Association of Insulin Pump Therapy vs Insulin Injection Therapy With Severe Hypoglycemia, Ketoacidosis, and Glycemic Control Among Children, Adolescents, and Young Adults With Type 1 Diabetes.

PubMed

Karges, Beate; Schwandt, Anke; Heidtmann, Bettina; Kordonouri, Olga; Binder, Elisabeth; Schierloh, Ulrike; Boettcher, Claudia; Kapellen, Thomas; Rosenbauer, Joachim; Holl, Reinhard W

2017-10-10

Insulin pump therapy may improve metabolic control in young patients with type 1 diabetes, but the association with short-term diabetes complications is unclear. To determine whether rates of severe hypoglycemia and diabetic ketoacidosis are lower with insulin pump therapy compared with insulin injection therapy in children, adolescents, and young adults with type 1 diabetes. Population-based cohort study conducted between January 2011 and December 2015 in 446 diabetes centers participating in the Diabetes Prospective Follow-up Initiative in Germany, Austria, and Luxembourg. Patients with type 1 diabetes younger than 20 years and diabetes duration of more than 1 year were identified. Propensity score matching and inverse probability of treatment weighting analyses with age, sex, diabetes duration, migration background (defined as place of birth outside of Germany or Austria), body mass index, and glycated hemoglobin as covariates were used to account for relevant confounders. Type 1 diabetes treated with insulin pump therapy or with multiple (≥4) daily insulin injections. Primary outcomes were rates of severe hypoglycemia and diabetic ketoacidosis during the most recent treatment year. Secondary outcomes included glycated hemoglobin levels, insulin dose, and body mass index. Of 30 579 patients (mean age, 14.1 years [SD, 4.0]; 53% male), 14 119 used pump therapy (median duration, 3.7 years) and 16 460 used insulin injections (median duration, 3.6 years). Patients using pump therapy (n = 9814) were matched with 9814 patients using injection therapy. Pump therapy, compared with injection therapy, was associated with lower rates of severe hypoglycemia (9.55 vs 13.97 per 100 patient-years; difference, -4.42 [95% CI, -6.15 to -2.69]; P < .001) and diabetic ketoacidosis (3.64 vs 4.26 per 100 patient-years; difference, -0.63 [95% CI, -1.24 to -0.02]; P = .04). Glycated hemoglobin levels were lower with pump therapy than with injection therapy (8.04% vs 8.22%; difference, -0.18 [95% CI, -0.22 to -0.13], P < .001). Total daily insulin doses were lower for pump therapy compared with injection therapy (0.84 U/kg vs 0.98 U/kg; difference, -0.14 [-0.15 to -0.13], P < .001). There was no significant difference in body mass index between both treatment regimens. Similar results were obtained after propensity score inverse probability of treatment weighting analyses in the entire cohort. Among young patients with type 1 diabetes, insulin pump therapy, compared with insulin injection therapy, was associated with lower risks of severe hypoglycemia and diabetic ketoacidosis and with better glycemic control during the most recent year of therapy. These findings provide evidence for improved clinical outcomes associated with insulin pump therapy compared with injection therapy in children, adolescents, and young adults with type 1 diabetes.

What Are the Safety Considerations for Insulin Control for Athletes?

ERIC Educational Resources Information Center

McDaniel, Larry W.; Olson, Sara; Gaudet, Laura; Jackson, Allen

2010-01-01

Athletes diagnosed with diabetes may have difficulty with their blood sugar levels fluctuating during intense exercise. Considerations for athletes with insulin concerns may range anywhere from exercise rehabilitation to the use of an automatic insulin pump. The automatic insulin pump is a small battery-operated device about the size of a pager.…

Insulin Pump and CGM Usage in the United States and Germany

PubMed Central

Walsh, John; Roberts, Ruth; Weber, Dietmar; Faber-Heinemann, Gabriele; Heinemann, Lutz

2015-01-01

Background: This survey collected and evaluated user responses about routine tasks and preferences regarding insulin pumps and infusion sets (IIS) with comparison of intercountry differences between the United States (US) and Germany (GER), chosen for their large insulin pump populations. Methods: A total of 985 subjects (534 US, 451 GER; 60% female) with type 1 diabetes on pump therapy anonymously answered 20 pump-related questions. US subjects also answered 11 questions about continuous glucose monitoring (CGM) usage. Results: Length of use of insulin cartridges is shorter in US than in GER, mean (SD) 4.3 (5.0) versus 5.3 (3.2) days (P < .001), while the IIS is used longer: 3.3 (1.0) versus 2.7 (1.1) days (P < .001). Lower self-reported HbA1c levels were associated with longer use of insulin cartridges (7.3% for >3 days vs 7.7% for <3 days; P < .01), and with use of an auto-insertion device (vs manual IIS insertion) in the US (7.2% vs 6.9%), but not in GER (7.7% vs 7.9%). Only 47% of pump wearers stated that they were “very satisfied” with their pump (49% US vs 45% GER, ns). However, 98% would recommend the pump to others (95% vs 93%, ns). Analysis of CGM questions showed that 297 (60%) of 496 US responders currently wore one. Of these, 84% said they would recommend CGM to others. CGM wearers who stated they were “very satisfied” with their CGM had lower HbA1c than those who said they were “partly satisfied” (6.9% vs 7.2%). Conclusions: This survey shows interesting differences in real-world use of insulin pumps in 2 large markets, and suggests areas where insulin pumps and CGMs might be improved. PMID:26071425

Long-term study of tubeless insulin pump therapy compared to multiple daily injections in youth with type 1 diabetes: Data from the German/Austrian DPV registry.

PubMed

Danne, Thomas; Schwandt, Anke; Biester, Torben; Heidtmann, Bettina; Rami-Merhar, Birgit; Haberland, Holger; Müther, Silvia; Khodaverdi, Semik; Haak, Thomas; Holl, Reinhard W

2018-02-15

To examine glycemic control in youth with type 1 diabetes (T1D) who switched from multiple daily injections (MDI) to a tubeless insulin pump (Omnipod Insulin Management System, Insulet Corporation, Billerica, Massachusetts) compared to patients who continued MDI therapy over a 3-year time period. This retrospective analysis of the German/Austrian Diabetes Patienten Verlaufsdokumentation registry included data from 263 centers and 2529 patients <20 years (n = 660 tubeless insulin pump; n = 1869 MDI) who initiated treatment on a tubeless insulin pump as of January 1, 2013 and had 1 year of data preswitch from MDI and 3 years of data postswitch to a tubeless pump. Outcomes included the change in glycated hemoglobin (HbA1c), insulin dose, and body mass index (BMI) SD score (SDS). Youth with T1D who switched from MDI therapy to a tubeless insulin pump showed better glycemic control at 1 year compared to patients who continued MDI treatment, adjusted mean ± SE: 7.5% ± 0.03% (58 mmol/mol) vs 7.7% ± 0.02% (61 mmol/mol); P < .001, with no between-group difference at 2 and 3 years. Total daily insulin dose was lower (P < .001) in the tubeless insulin pump group, 0.80 ± 0.01, 0.81 ± 0.01, and 0.85 ± 0.01 U/kg, vs the MDI group, 0.89 ± 0.01, 0.94 ± 0.01, and 0.97 ± 0.01 U/kg, at 1, 2, and 3 years, respectively (all P < .001). BMI SDS increased in both groups and was not different over time. Treatment with a tubeless insulin pump in youth with T1D was associated with improvements in glycemic control compared to MDI after 1 year and appears to be an effective alternative to MDI. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The automatic regulation of the basal dose on the insulin pump for the treatment of patients that have diabetes type 1

PubMed Central

Mehanović, Sifet; Mujić, Midhat

2010-01-01

Diabetes mellitus type 1 is a chronic metabolic disorder, and its main characteristic is Hyperglycemia. It usually occurs in the early years because of the absolute or relative absence of the active insulin that is caused by the autoimmune disease of the β cells of the pancreas. Despite the numerous researches and efforts of the scientists, the therapy for Diabetes type 1 is based on the substitution of insulin. Even though the principles of the therapy have not changed so much, still some important changes have occurred in the production and usage of insulin. Lately, the insulin pumps are more frequent in the therapy for Diabetes type 1. The functioning of the pump is based on the continuing delivery of insulin in a small dose (“the basal dose”), that keeps the level of glycemia in the blood constant. The increase of glycemia during the meal is reduced with the additional dose of insulin (“the bolus dose”). The use of the insulin pumps and the continuing glucose sensors has provided an easier and more efficient monitoring of the diabetes, a better metabolic control and a better life quality for the patient and his/her family. This work presents the way of automatic regulation of the basal dose of insulin through the synthesis of the functions of the insulin pump and the continuing glucose sensor. The aim is to give a contribution to the development of the controlling algorithm on the insulin pump for the automatic regulation of the glucose concentration in the blood. This could be a step further which is closer to the delivery of the dose of insulin that is really needed for the basic needs of the organism, and a significant contribution is given to the development of the artificial pancreas. PMID:20507288

The automatic regulation of the basal dose on the insulin pump for the treatment of patients that have Diabetes type 1.

PubMed

Mehanović, Sifet; Mujić, Midhat

2010-05-01

Diabetes mellitus type 1 is a chronic metabolic disorder, and its main characteristic is Hyperglycemia. It usually occurs in the early years because of the absolute or relative absence of the active insulin that is caused by the autoimmune disease of the beta cells of the pancreas. Despite the numerous researches and efforts of the scientists, the therapy for Diabetes type 1 is based on the substitution of insulin. Even though the principles of the therapy have not changed so much, still some important changes have occurred in the production and usage of insulin. Lately, the insulin pumps are more frequent in the therapy for Diabetes type 1. The functioning of the pump is based on the continuing delivery of insulin in a small dose ("the basal dose"), that keeps the level of glycemia in the blood constant. The increase of glycemia during the meal is reduced with the additional dose of insulin ("the bolus dose"). The use of the insulin pumps and the continuing glucose sensors has provided an easier and more efficient monitoring of the diabetes, a better metabolic control and a better life quality for the patient and his/her family. This work presents the way of automatic regulation of the basal dose of insulin through the synthesis of the functions of the insulin pump and the continuing glucose sensor. The aim is to give a contribution to the development of the controlling algorithm on the insulin pump for the automatic regulation of the glucose concentration in the blood. This could be a step further which is closer to the delivery of the dose of insulin that is really needed for the basic needs of the organism, and a significant contribution is given to the development of the artificial pancreas.

The effectiveness of continuous subcutaneous insulin pumps with continuous glucose monitoring in outpatient adolescents with type 1 diabetes: A systematic review.

PubMed

Matsuda, Erin; Brennan, Patricia

The review question is: Are metabolic outcomes improved in outpatient adolescents (aged 13 to 19 years) with type 1 diabetes on a Continuous Subcutaneous Insulin Infusion (CSII) when continuous glucose monitoring is used, compared to self-glucose monitoring alone? Type 1 diabetes is the most common childhood paediatric disease, characterised by impairment of insulin producing βeta-cells in the pancreas. Internationally, there is variation in the incidence of type 1 diabetes in paediatric patients. According to the Center for Disease Control and Prevention (CDC) and the SEARCH for Diabetes in Youth Study Group, the overall incidence rate of this autoimmune disease is 24.3/100,000 in those 19 years of age . Annually, more than 15,000 children and adolescents are diagnosed in the United States (US) . From 1990 to 1999, the World Health Organization (WHO) launched the Multinational Project for Childhood Diabetes (DIAMOND), which was tasked with assessing type 1 diabetes in those 14 years or younger worldwide . Finland was discovered to have the highest age-adjusted incidence at 40.9 cases per 100,000/year. The lowest age-adjusted incidence is in China and Venezuela at 0.1 cases per 100,000/year. Globally, the largest increase in incidence is in those aged 10 to 14 years . This systematic review will focus on adolescent patients with type 1 diabetes, aged 13 to 19 years who manage their diabetes with an insulin pump.Patients with type 1 diabetes mellitus typically present with a history of polydipsia, polyuria, polyphagia, and weight loss . Initial findings include hyperglycemia, glycosuria, and ketones in the blood or urine . In 2009, the International Expert Committee deemed a haemoglobin A1C (glycosylated haemoglobin) of 6.5% or higher to be the standard for diagnosis . The American Diabetes Association (ADA) as well as the International Diabetes Federation and the European Association Study of Diabetes (EASD) accept this measure as the diagnostic tool for diabetes. Haemoglobin A1C is the most commonly used measurement for patients with type 1 diabetes . It refers to the measurement of the amount of glucose bound to haemoglobin. It is an average of blood glucose levels for the last 120 days, which is consistent with the average life span of a red blood cell (RBC).Compensation for the lack of insulin-secreting βeta-cells is accomplished through administration of insulin. For adolescents, insulin dosing is based on pubescent status, age, weight, activity level, and amount of carbohydrates consumed . Insulin administration, carbohydrate counting, and correction of hyperglycemia are necessary for maintaining glycemic control. Insulin can be administered through multiple daily injections (MDI) of rapid, intermediate and long-acting insulin .Another form of insulin delivery is the Continuous Subcutaneous Insulin Infusion (CSII), also known as an insulin pump, which is designed to meet physiological requirements through programmable basal rates and bolus doses . CSII's utilise rapid-acting insulin and establish a basal rate, which replaces the need for long-acting insulin. Bolus dosing is accomplished through adjusting the pump and is utilised to account for nutritional intake as well as hyperglycemia correction. Adjustments are also made for physical activity and exercise, as this can affect glucose levels . All patients considered in this systematic review will be utilising insulin pumps.In 2006, the United States had more than 35,000 patients, under the age of 21 years, receiving insulin therapy through an insulin pump . In Europe, the percentage of people with type 1 diabetes utilising a CSII is lower, potentially due to variation in health care coverage . There are various forms of insulin pumps, all with similar capabilities including a dose calculator for high blood glucose correction and carbohydrate ratios, programming software, and several other features . Software and programming is specific to each manufacturer. Basal rate abilities vary in each model from 0.05 units/hour to 30 units/hour . Information from the pump can be uploaded to online registries allowing providers to review trends and usage. It is imperative the information is reviewed concurrently with glucose monitoring results in order to ensure appropriate dosing and treatment .The intervention considered in this systematic review is the use of continuous glucose monitoring (CGM) in conjunction with a CSII. CGM utilises a sensor placed in the interstitial subcutaneous tissue, which then measures glucose levels. This is accomplished with "electrochemical sensors that use glucose oxidase and measure an electric current generated when glucose reacts with oxygen. The sensors are coated with a specialised membrane to make them biocompatible" . The CGM has programmable high and low levels to alert the user when the limit is being reached. Information regarding continuous glucose levels can then be downloaded and reviewed. Based on the report, providers, patients, and caregivers may assess trends and consider changing basal rates or bolus doses .CGM sensors currently do not offer a closed-loop solution. The user must enter insulin dosing information into the pump, taking into account the present glucose level and duration of action of the insulin. Currently, CGMs are regarded as a supplemental method for assessing the effectiveness of glucose control. Existing studies are underway to improve accuracy and communication between the sensor and insulin pump with the goal to develop an artificial pancreas . Currently, CGM sensors must be calibrated with a glucometer, as specified by the manufacturer .The comparison for this review is the standard of care, self-glucose monitoring (SGM), in patients with insulin pumps . SGM is accomplished with a glucometer and blood sample typically obtained from a finger prick. The Diabetes Control and Complications Trial (DCCT) demonstrated frequency of monitoring improves glycemic control and decreases the risk of comorbidity . Data from this significant study continues to contribute to current diabetes management. According to the ADA, children and adolescents should monitor their blood glucose at least three or more times per day. Blood glucose data is utilised to calculate appropriate insulin doses. Similar to the CGM, information from the glucometers can be downloaded for assessment of results and trends. However, the result is dependent on the action of the patient to obtain the sample and only represents a specific moment in time whereas the CGM sensor continuously tracks the blood glucose level. Depending on the model, CGM can provide glucose levels every one to ten minutes. The sensor may last for up to 72 hours and results are available in real time .This systematic review will address two metabolic outcomes: a decrease in the number of hypoglycemic episodes and a haemoglobin A1C level <7.5%. These outcomes were chosen due to their significance as indicators in the management of type 1 diabetes. Glucose levels should be between 90 mg/dL and 130 mg/dL (5.0mmol/l and 7.2mmol/l) before meals and between 90 mg/dL and 150 mg/dL at night (5.0mmmol/l and 8.3mmol/l) . Optimal care of an adolescent with type 1 diabetes mellitus is to safely maintain glycemic control and avoid hypoglycemia.Haemoglobin A1C is an indicator of how well the disease is being managed and should be evaluated every three months. McCulloch recommends the haemoglobin A1C level should be compared to approximately 50 recent blood glucose readings to ensure the accuracy of patient SGM . The reliability and validity of this test is based on the evidence discovered by the DCCT demonstrating those with lower haemoglobin A1C levels have fewer complications . The target A1C for adolescents, aged 13 to 19 years of age, is <7.5% . This is consistent with the National Institute of Clinical Excellence (NICE) and diabetes management guidelines of the Australasian Paediatric Endocrine Group for the Department of Health and Ageing .An initial search for a systematic review regarding insulin pumps in adolescents with type 1 diabetes mellitus and concurrent use of CGM was conducted in the Joanna Briggs Institute Library of Systematic Reviews, Cochrane Database of Systematic Reviews, and PubMed. No systematic reviews were found.

Insulin Pump and Continuous Glucose Monitor Initiation in Hospitalized Patients with Type 2 Diabetes Mellitus.

PubMed

Levitt, David L; Spanakis, Elias K; Ryan, Kathleen A; Silver, Kristi D

2018-01-01

Insulin pumps and continuous glucose monitoring (CGM) are commonly used by patients with diabetes mellitus in the outpatient setting. The efficacy and safety of initiating inpatient insulin pumps and CGM in the nonintensive care unit setting is unknown. In a prospective pilot study, inpatients with type 2 diabetes were randomized to receive standard subcutaneous basal-bolus insulin and blinded CGM (group 1, n = 5), insulin pump and blinded CGM (group 2, n = 6), or insulin pump and nonblinded CGM (group 3, n = 5). Feasibility, glycemic control, and patient satisfaction were evaluated among groups. Group 1 had lower mean capillary glucose levels, 144.5 ± 19.5 mg/dL, compared with groups 2 and 3, 191.5 ± 52.3 and 182.7 ± 59.9 mg/dL (P 1 vs. 2+3  = 0.05). CGM detected 19 hypoglycemic episodes (glucose <70 mg/dL) among all treatment groups, compared with 12 episodes detected by capillary testing, although not statistically significant. No significant differences were found for the total daily dose of insulin or percentage of time spent below target glucose range (<90 mg/dL), in target glucose range (90-180 mg/dL), or above target glucose range (>180 mg/dL). On the Diabetes Treatment Satisfaction Questionnaire-Change, group 3 reported increased hyperglycemia and decreased hypoglycemia frequency compared with the other two groups, although the differences did not reach statistical significance. Insulin pump and CGM initiation are feasible during hospitalization, although they are labor intensive. Although insulin pump initiation may not lead to improved glycemic control, there is a trend toward CGM detecting a greater number of hypoglycemic episodes. Larger studies are needed to determine whether use of this technology can lower inpatient morbidity and mortality.

Association of Insulin Pump Therapy vs Insulin Injection Therapy With Severe Hypoglycemia, Ketoacidosis, and Glycemic Control Among Children, Adolescents, and Young Adults With Type 1 Diabetes

PubMed Central

Karges, Beate; Schwandt, Anke; Heidtmann, Bettina; Kordonouri, Olga; Binder, Elisabeth; Schierloh, Ulrike; Boettcher, Claudia; Kapellen, Thomas; Rosenbauer, Joachim; Holl, Reinhard W.

2017-01-01

Importance Insulin pump therapy may improve metabolic control in young patients with type 1 diabetes, but the association with short-term diabetes complications is unclear. Objective To determine whether rates of severe hypoglycemia and diabetic ketoacidosis are lower with insulin pump therapy compared with insulin injection therapy in children, adolescents, and young adults with type 1 diabetes. Design, Setting, and Participants Population-based cohort study conducted between January 2011 and December 2015 in 446 diabetes centers participating in the Diabetes Prospective Follow-up Initiative in Germany, Austria, and Luxembourg. Patients with type 1 diabetes younger than 20 years and diabetes duration of more than 1 year were identified. Propensity score matching and inverse probability of treatment weighting analyses with age, sex, diabetes duration, migration background (defined as place of birth outside of Germany or Austria), body mass index, and glycated hemoglobin as covariates were used to account for relevant confounders. Exposures Type 1 diabetes treated with insulin pump therapy or with multiple (≥4) daily insulin injections. Main Outcomes and Measures Primary outcomes were rates of severe hypoglycemia and diabetic ketoacidosis during the most recent treatment year. Secondary outcomes included glycated hemoglobin levels, insulin dose, and body mass index. Results Of 30 579 patients (mean age, 14.1 years [SD, 4.0]; 53% male), 14 119 used pump therapy (median duration, 3.7 years) and 16 460 used insulin injections (median duration, 3.6 years). Patients using pump therapy (n = 9814) were matched with 9814 patients using injection therapy. Pump therapy, compared with injection therapy, was associated with lower rates of severe hypoglycemia (9.55 vs 13.97 per 100 patient-years; difference, −4.42 [95% CI, −6.15 to −2.69]; P < .001) and diabetic ketoacidosis (3.64 vs 4.26 per 100 patient-years; difference, −0.63 [95% CI, −1.24 to −0.02]; P = .04). Glycated hemoglobin levels were lower with pump therapy than with injection therapy (8.04% vs 8.22%; difference, −0.18 [95% CI, −0.22 to −0.13], P < .001). Total daily insulin doses were lower for pump therapy compared with injection therapy (0.84 U/kg vs 0.98 U/kg; difference, −0.14 [−0.15 to −0.13], P < .001). There was no significant difference in body mass index between both treatment regimens. Similar results were obtained after propensity score inverse probability of treatment weighting analyses in the entire cohort. Conclusions and Relevance Among young patients with type 1 diabetes, insulin pump therapy, compared with insulin injection therapy, was associated with lower risks of severe hypoglycemia and diabetic ketoacidosis and with better glycemic control during the most recent year of therapy. These findings provide evidence for improved clinical outcomes associated with insulin pump therapy compared with injection therapy in children, adolescents, and young adults with type 1 diabetes. PMID:29049584

Insulin Infusion Sets: A Critical Reappraisal.

PubMed

Heinemann, Lutz

2016-05-01

An insulin infusion set (IIS) is a key component of insulin pumps. In daily practice issues with the IIS appear to be as relevant for a successful insulin therapy as the pumps themselves. The insulin is applied to the subcutaneous tissue via a Teflon(®) (Dupont, Wilmington, DE) or steel cannula. There are intensive discussions about the impact the choice of material for insulin application has on insulin pharmacokinetics. In this review, this factor and others that are known to have an impact on the successful usage of IIS are discussed.

Continuous subcutaneous insulin infusion therapy for Type 1 diabetes mellitus in children.

PubMed

Mavinkurve, M; Quinn, A; O'Gorman, C S

2016-05-01

Continuous subcutaneous insulin pump therapy (CSII or pump therapy) is a well-recognised treatment option for Type 1 diabetes mellitus (T1DM) in paediatrics. It is especially suited to children because it optimises control by improving flexibility across age-specific lifestyles. The NICE guidelines (2008) recognise that pump therapy is advantageous and that it should be utilised to deliver best practice. In Ireland, the National Clinical Program for Diabetes will increase the availability and uptake of CSII in children and thus more clinicians are likely to encounter children using CSII therapy. This is a narrative review which discusses the basic principles of pump therapy and focuses on aspects of practical management. Insulin pump management involves some basic yet important principles which optimise the care of diabetes in children. This review addresses the principles of insulin pump management in children which all health care professionals involved in caring for the child with diabetes, shoud be familiar with.

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial.

PubMed

Heller, Simon; White, David; Lee, Ellen; Lawton, Julia; Pollard, Daniel; Waugh, Norman; Amiel, Stephanie; Barnard, Katharine; Beckwith, Anita; Brennan, Alan; Campbell, Michael; Cooper, Cindy; Dimairo, Munyaradzi; Dixon, Simon; Elliott, Jackie; Evans, Mark; Green, Fiona; Hackney, Gemma; Hammond, Peter; Hallowell, Nina; Jaap, Alan; Kennon, Brian; Kirkham, Jackie; Lindsay, Robert; Mansell, Peter; Papaioannou, Diana; Rankin, David; Royle, Pamela; Smithson, W Henry; Taylor, Carolin

2017-04-01

Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment. To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy. Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI. Eight secondary care diabetes centres in the UK. Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps. Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm ® Veo TM (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK). Primary outcome - change in glycated haemoglobin (HbA 1c ) at 2 years in participants whose baseline HbA 1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA 1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness. We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA 1c of ≥ 7.5%. HbA 1c and severe hypoglycaemia improved in both groups. The drop in HbA 1c % at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA 1c change at 2 years, at which the baseline HbA 1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump ( p  = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps ( p  = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews. Blinding of pump therapy was not possible, although an objective primary outcome was used. Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM. To understand why few patients achieve a HbA 1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries. Current Controlled Trials ISRCTN61215213. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 21, No. 20. See the NIHR Journals Library website for further project information.

Benefits of three-month continuous glucose monitoring for persons with diabetes using insulin pumps and sensors.

PubMed

Peterson, Karolina; Zapletalova, Jana; Kudlova, Pavla; Matuskova, Veronika; Bartek, Josef; Novotny, Dalibor; Chlup, Rudolf

2009-03-01

The latest Paradigm 722 insulin pump, Medtronic MiniMed, USA, enables daily reading of 288 interstitial fluid glucose concentrations determined by a sensor inserted into subcutaneous tissue; the sensor signals are transmitted into the insulin pump, enabling the patient to see real-time glucose concentration on the display and adapt further treatment. To assess the evolution of HbA1c over the course of a 3-month period in two cohorts of persons with type 1 (n=39) or type 2 (n=3) diabetes (PWD): 1) PWD on Paradigm 722 using sensors for continuous glucose monitoring (CGM group), 2) PWD on other types of insulin pumps performing intensive self-monitoring as before (3 to 6 times/d) on glucometer Linus, Wellion, Agamatrix (control group). Compliant PWDs using insulin pump with insulin aspart for several previous months were included in the study. Seventeen were put on Paradigm 722 with CGM and 25 were included in the control group. Paired t-test and the statistical program SPSS v.15.0 were used to analyze the data. There was no significant difference in age between the two groups (P=0.996), in diabetes duration (P=0.482) or in daily insulin dose (P=0.469). In the CGM group (but not in the control group) HbA1c/IFCC dropped from 6.98+/-0.43 % to 5.98+/-0.36 % (P=0.006) within 1 month and remained reduced. The use of the Paradigm 722 insulin pump with CGM resulted in significant improvement in HbA1c which appeared within one month and remained throughout the whole 3-month study period. No significant improvement in HbA1c was seen in the control group.

Diabetic ketoacidosis

MedlinePlus

... you are sick. If you use an insulin pump, check often to see that insulin is flowing ... is not blocked, kinked or disconnected from the pump. Alternative Names DKA; Ketoacidosis; Diabetes - ketoacidosis Images Food ...

Clinical review: insulin pump-associated adverse events in adults and children.

PubMed

Ross, P L; Milburn, J; Reith, D M; Wiltshire, E; Wheeler, B J

2015-12-01

Insulin pumps are a vital and rapidly developing tool in the treatment of type 1 diabetes mellitus in both adults and children. Many studies have highlighted outcomes and assessed their potential advantages, but much of the data on adverse outcomes are limited and often based on outdated technology. We aimed to review and summarize the available literature on insulin pump-associated adverse events in adults and children. A literature search was undertaken using PubMed, EMBASE, and the Cochrane library. Articles were then screened by title, followed by abstract, and full text as needed. A by-hand search of reference lists in identified papers was also utilised. All searches were limited to English language material, but no time limits were used. Current and past literature regarding insulin pump-associated adverse events is discussed, including potential metabolic and non-metabolic adverse events, in particular: pump malfunction; infusion set/site issues; and cutaneous problems. We show that even with modern technology, adverse events are common, occurring in over 40 % of users per year, with a minority, particularly in children, requiring hospital management. Hyperglycaemia and ketosis are now the most common consequences of adverse events and are usually associated with infusion set failure. This differs from older technology where infected infusion sites predominated. This timely review covers all potential insulin pump-associated adverse events, including their incidence, features, impacts, and contributory factors such as the pump user. The importance of ongoing anticipatory education and support for patients and families using this intensive insulin technology is highlighted, which if done well should improve the overall experience of pump therapy for users, and hopefully reduce the incidence and impact of severe adverse events.

Race, socioeconomic status, and treatment center are associated with insulin pump therapy in youth in the first year following diagnosis of type 1 diabetes

USDA-ARS?s Scientific Manuscript database

Increasing numbers of children and adolescents with type 1 diabetes (T1D) have been placed on insulin pump therapy. Nevertheless, data are limited regarding patterns of pump use during the first year of treatment and the clinical and socioeconomic factors associated with early use of pump therapy. T...

Relative effectiveness of insulin pump treatment over multiple daily injections and structured education during flexible intensive insulin treatment for type 1 diabetes: cluster randomised trial (REPOSE).

PubMed

2017-03-30

Objective  To compare the effectiveness of insulin pumps with multiple daily injections for adults with type 1 diabetes, with both groups receiving equivalent training in flexible insulin treatment. Design  Pragmatic, multicentre, open label, parallel group, cluster randomised controlled trial (Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE) trial). Setting  Eight secondary care centres in England and Scotland. Participants  Adults with type 1 diabetes who were willing to undertake intensive insulin treatment, with no preference for pumps or multiple daily injections. Participants were allocated a place on established group training courses that taught flexible intensive insulin treatment ("dose adjustment for normal eating," DAFNE). The course groups (the clusters) were then randomly allocated in pairs to either pump or multiple daily injections. Interventions  Participants attended training in flexible insulin treatment (using insulin analogues) structured around the use of pump or injections, followed for two years. Main outcome measures  The primary outcomes were a change in glycated haemoglobin (HbA1c) values (%) at two years in participants with baseline HbA1c value of ≥7.5% (58 mmol/mol), and the proportion of participants achieving an HbA1c value of <7.5%. Secondary outcomes included body weight, insulin dose, and episodes of moderate and severe hypoglycaemia. Ancillary outcomes included quality of life and treatment satisfaction. Results  317 participants (46 courses) were randomised (156 pump and 161 injections). 267 attended courses and 260 were included in the intention to treat analysis, of which 235 (119 pump and 116 injection) had baseline HbA1c values of ≥7.5%. Glycaemic control and rates of severe hypoglycaemia improved in both groups. The mean change in HbA1c at two years was -0.85% with pump treatment and -0.42% with multiple daily injections. Adjusting for course, centre, age, sex, and accounting for missing values, the difference was -0.24% (-2.7 mmol/mol) in favour of pump users (95% confidence interval -0.53 to 0.05, P=0.10). Most psychosocial measures showed no difference, but pump users showed greater improvement in treatment satisfaction and some quality of life domains (dietary freedom and daily hassle) at 12 and 24 months. Conclusions  Both groups showed clinically relevant and long lasting decreases in HbA1c, rates of severe hypoglycaemia, and improved psychological measures, although few participants achieved glucose levels currently recommended by national and international guidelines. Adding pump treatment to structured training in flexible intensive insulin treatment did not substantially enhance educational benefits on glycaemic control, hypoglycaemia, or psychosocial outcomes in adults with type 1 diabetes. These results do not support a policy of providing insulin pumps to adults with poor glycaemic control until the effects of training on participants' level of engagement in intensive self management have been determined. Trial registration  Current Controlled Trials ISRCTN61215213. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

New-generation diabetes management: glucose sensor-augmented insulin pump therapy

PubMed Central

Cengiz, Eda; Sherr, Jennifer L; Weinzimer, Stuart A; Tamborlane, William V

2011-01-01

Diabetes is one of the most common chronic disorders with an increasing incidence worldwide. Technologic advances in the field of diabetes have provided new tools for clinicians to manage this challenging disease. For example, the development of continuous subcutaneous insulin infusion systems have allowed for refinement in the delivery of insulin, while continuous glucose monitors provide patients and clinicians with a better understanding of the minute to minute glucose variability, leading to the titration of insulin delivery based on this variability when applicable. Merging of these devices has resulted in sensor-augmented insulin pump therapy, which became a major building block upon which the artificial pancreas (closed-loop systems) can be developed. This article summarizes the evolution of sensor-augmented insulin pump therapy until present day and its future applications in new-generation diabetes management. PMID:21728731

New-generation diabetes management: glucose sensor-augmented insulin pump therapy.

PubMed

Cengiz, Eda; Sherr, Jennifer L; Weinzimer, Stuart A; Tamborlane, William V

2011-07-01

Diabetes is one of the most common chronic disorders with an increasing incidence worldwide. Technologic advances in the field of diabetes have provided new tools for clinicians to manage this challenging disease. For example, the development of continuous subcutaneous insulin infusion systems have allowed for refinement in the delivery of insulin, while continuous glucose monitors provide patients and clinicians with a better understanding of the minute to minute glucose variability, leading to the titration of insulin delivery based on this variability when applicable. Merging of these devices has resulted in sensor-augmented insulin pump therapy, which became a major building block upon which the artificial pancreas (closed-loop systems) can be developed. This article summarizes the evolution of sensor-augmented insulin pump therapy until present day and its future applications in new-generation diabetes management.

Assessment of implantable infusion pumps for continuous infusion of human insulin in rats: potential for group housing.

PubMed

Jensen, Vivi Flou Hjorth; Mølck, Anne-Marie; Mårtensson, Martin; Strid, Mette Aagaard; Chapman, Melissa; Lykkesfeldt, Jens; Bøgh, Ingrid Brück

2017-06-01

Group housing is considered to be important for rats, which are highly sociable animals. Single housing may impact behaviour and levels of circulating stress hormones. Rats are typically used in the toxicological evaluation of insulin analogues. Human insulin (HI) is frequently used as a reference compound in these studies, and a comparator model of persistent exposure by HI infusion from external pumps has recently been developed to support toxicological evaluation of long-acting insulin analogues. However, this model requires single housing of the animals. Developing an insulin-infusion model which allows group housing would therefore greatly improve animal welfare. The aim of the present study was to investigate the suitability of implantable infusion pumps for HI infusion in group-housed rats. Group housing of rats implanted with a battery-driven pump proved to be possible. Intravenous infusion of HI lowered blood glucose levels persistently for two weeks, providing a comparator model for use in two-week repeated-dose toxicity studies with new long-acting insulin analogues, which allows group housing, and thereby increasing animal welfare compared with an external infusion model.

Insulin pump therapy with automated insulin suspension in response to hypoglycemia: reduction in nocturnal hypoglycemia in those at greatest risk.

PubMed

Choudhary, Pratik; Shin, John; Wang, Yongyin; Evans, Mark L; Hammond, Peter J; Kerr, David; Shaw, James A M; Pickup, John C; Amiel, Stephanie A

2011-09-01

To evaluate a sensor-augmented insulin pump with a low glucose suspend (LGS) feature that automatically suspends basal insulin delivery for up to 2 h in response to sensor-detected hypoglycemia. The LGS feature of the Paradigm Veo insulin pump (Medtronic, Inc., Northridge, CA) was tested for 3 weeks in 31 adults with type 1 diabetes. There were 166 episodes of LGS: 66% of daytime LGS episodes were terminated within 10 min, and 20 episodes lasted the maximum 2 h. LGS use was associated with reduced nocturnal duration ≤2.2 mmol/L in those in the highest quartile of nocturnal hypoglycemia at baseline (median 46.2 vs. 1.8 min/day, P = 0.02 [LGS-OFF vs. LGS-ON]). Median sensor glucose was 3.9 mmol/L after 2-h LGS and 8.2 mmol/L at 2 h after basal restart. Use of an insulin pump with LGS was associated with reduced nocturnal hypoglycemia in those at greatest risk and was well accepted by patients.

Insulin pump-associated adverse events are common, but not associated with glycemic control, socio-economic status, or pump/infusion set type.

PubMed

Ross, P; Gray, A R; Milburn, J; Kumarasamy, I M; Wu, F; Farrand, S; Armishaw, J; Wiltshire, E; Rayns, J; Tomlinson, P; Wheeler, B J

2016-12-01

While there have been many outcome-focussed studies examining insulin pump therapy, only a few have looked at potential adverse events (AEs), with none examining the relationship between AEs and pump/infusion set type, ethnicity or socio-economic status. In addition, current data on the incidence and characteristics of pump-associated AEs are confined to one paediatric centre. We aimed to describe the incidence, characteristics and potential predictors of insulin pump-associated AEs in New Zealand adults and children with T1DM. We approached adults and families of children with T1DM on insulin pumps in four main New Zealand centres. Participants completed a questionnaire examining pump-related issues they had experienced in the preceding 12 months. Response rate was 64 % with 174 of 270 eligible people participating in the study. 84 % of subjects reported one or more AEs, with an overall AE incidence of 3.42 per person/year (95 % CI 3.14, 3.73). An event serious enough to require a hospital presentation occurred in 9.8 %, all but one reporting high ketones or diabetic ketoacidosis (DKA). Set/site problems were the AE most commonly reported (by 53 % of respondents), followed by cutaneous complications (43 %) and pump malfunction (38 %). Few predictors of AEs (of any type) were found; however, a negative binomial regression model found that a longer duration of pumping (p = 0.018) and age <18 years (p = 0.043) were both associated with fewer AEs (all types combined). Insulin pump-associated AEs are very common. However, few variables are predictive of them with no relationships seen with glycaemic control, socio-economic status, pump manufacturer or infusion set type. Based on these findings, AEs should be anticipated in both adults and children, with anticipatory patient education and training recommended for their successful and safe use.

Sensor-Augmented Insulin Pumps and Hypoglycemia Prevention in Type 1 Diabetes.

PubMed

Steineck, Isabelle; Ranjan, Ajenthen; Nørgaard, Kirsten; Schmidt, Signe

2017-01-01

Hypoglycemia can lead to seizures, unconsciousness, or death. Insulin pump treatment reduces the frequency of severe hypoglycemia compared with multiple daily injections treatment. The addition of a continuous glucose monitor, so-called sensor-augmented pump (SAP) treatment, has the potential to further limit the duration and severity of hypoglycemia as the system can detect and in some systems act on impending and prevailing low blood glucose levels. In this narrative review we summarize the available knowledge on SAPs with and without automated insulin suspension, in relation to hypoglycemia prevention. We present evidence from randomized trials, observational studies, and meta-analyses including nonpregnant individuals with type 1 diabetes mellitus. We also outline concerns regarding SAPs with and without automated insulin suspension. There is evidence that SAP treatment reduces episodes of moderate and severe hypoglycemia compared with multiple daily injections plus self-monitoring of blood glucose. There is some evidence that SAPs both with and without automated suspension reduces the frequency of severe hypoglycemic events compared with insulin pumps without continuous glucose monitoring.

Experiences of children/young people and their parents, using insulin pump therapy for the management of type 1 diabetes: qualitative review.

PubMed

Alsaleh, F M; Smith, F J; Taylor, K M

2012-04-01

Advances in medical technology have made insulin pumps an attractive treatment option for patients with type 1 diabetes and in particular for children and young people. Previous studies have accounted the experiences and views of children/young people and their parents for the use of the injection therapy, but very few have focused on the use of insulin pumps. The objective of this review was to identify studies that explore the experiences of children/young people and their parents on the transition from injections to insulin pump therapy, in the context of their social life. A systematic literature search was conducted, and six studies meeting the inclusion and exclusion criteria were identified.   Views and perspectives from the studies identified mainly focused on: introduction to the pump; reasons for the transition to pump therapy; advantages and disadvantages of this treatment option; and impact on quality of life (QoL). Parents and/or children reported that they learned about pump therapy either formally from a healthcare professional or informally from a friend or the internet. Many reasons were identified for the transition, the most important being the pursuit of stable and controlled blood sugar levels and the desire for a more flexible lifestyle. Participants highlighted the advantages of insulin pumps in terms of improved diabetes control. Moreover, there was a positive impact on the QoL, as insulin pumps provided children greater flexibility in lifestyles especially with regards to meals and socialization. In contrast, psychosocial issues such as pump visibility and physical restrictions were highlighted as disadvantages. Issues such as day-to-day management were also discussed. Exploring children/young people's perspectives on the use of pump therapy for managing their diabetes, and parental reflections in caring for those children is important as it provides evidence informing policy for the wider implementation of this technology in the management of diabetes in children. However, the review revealed that there is a scarcity of data in this area and that further research is needed. © 2011 Blackwell Publishing Ltd.

Implantable batteryless device for on-demand and pulsatile insulin administration

NASA Astrophysics Data System (ADS)

Lee, Seung Ho; Lee, Young Bin; Kim, Byung Hwi; Lee, Cheol; Cho, Young Min; Kim, Se-Na; Park, Chun Gwon; Cho, Yong-Chan; Choy, Young Bin

2017-04-01

Many implantable systems have been designed for long-term, pulsatile delivery of insulin, but the lifetime of these devices is limited by the need for battery replacement and consequent replacement surgery. Here we propose a batteryless, fully implantable insulin pump that can be actuated by a magnetic field. The pump is prepared by simple-assembly of magnets and constituent units and comprises a drug reservoir and actuator equipped with a plunger and barrel, each assembled with a magnet. The plunger moves to noninvasively infuse insulin only when a magnetic field is applied on the exterior surface of the body. Here we show that the dose is easily controlled by varying the number of magnet applications. Also, pump implantation in diabetic rats results in profiles of insulin concentration and decreased blood glucose levels similar to those observed in rats treated with conventional subcutaneous insulin injections.

Risk factors for discontinuation of insulin pump therapy in pediatric and young adult patients.

PubMed

Kostev, Karel; Rockel, Timo; Rosenbauer, Joachim; Rathmann, Wolfgang

2014-12-01

Previous studies have shown that only a small number of pediatric and young adult patients discontinue pump therapy, but risk factors for discontinuation are unclear. To identify characteristics of pediatric and young adult patients with pump therapy which are associated with discontinuation of treatment. Retrospective cohort study using a representative nationwide database (LRx; IMS Health) in Germany covering >80% of all prescriptions to members of statutory health insurances in 2008-2011. All patients (age group <25 years) with new prescriptions of insulin pumps were identified (2009-2010) and were followed for 12 months. Overall, 2452 new pump users were identified, of whom 177 (7.2%) switched to other forms of insulin therapy within 12 months. In multivariate logistic regression, younger age (<6 years; reference 18 to <25 years: Odds ratio, OR, 95% CI: 0.36; 0.17-0.74) and use of teflon needles (reference steel needles: OR, 95% CI: 0.59; 0.41-0.83) were related to a lower odds of pump discontinuation. A non-significant trend was found for male sex (OR, 95% CI: 0.75; 0.52-1.08). Prescriptions of thyroid therapeutics (ATC H03A: OR, 95% CI: 1.79; 1.23-2.61) and antiepileptics (N03: OR, 95% CI: 3.14; 1.49-6.59) were significantly associated with discontinuation of pump therapy. About 93% of pediatric and young adult patients maintained insulin pump therapy within 12 months. Age <6 years, male sex and teflon needle use were associated with a lower risk of discontinuation. Thyroid therapy (indicating autoimmunity) and antiepileptic drug prescriptions were associated with a higher likelihood for discontinuation of insulin pump treatment. Copyright © 2014 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial.

PubMed Central

Heller, Simon; White, David; Lee, Ellen; Lawton, Julia; Pollard, Daniel; Waugh, Norman; Amiel, Stephanie; Barnard, Katharine; Beckwith, Anita; Brennan, Alan; Campbell, Michael; Cooper, Cindy; Dimairo, Munyaradzi; Dixon, Simon; Elliott, Jackie; Evans, Mark; Green, Fiona; Hackney, Gemma; Hammond, Peter; Hallowell, Nina; Jaap, Alan; Kennon, Brian; Kirkham, Jackie; Lindsay, Robert; Mansell, Peter; Papaioannou, Diana; Rankin, David; Royle, Pamela; Smithson, W Henry; Taylor, Carolin

2017-01-01

BACKGROUND Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment. OBJECTIVE To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy. DESIGN Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI. SETTING Eight secondary care diabetes centres in the UK. PARTICIPANTS Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps. INTERVENTIONS Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm(®) Veo(TM) (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK). MAIN OUTCOME MEASURES Primary outcome - change in glycated haemoglobin (HbA1c) at 2 years in participants whose baseline HbA1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness. RESULTS We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA1c of ≥ 7.5%. HbA1c and severe hypoglycaemia improved in both groups. The drop in HbA1c% at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA1c change at 2 years, at which the baseline HbA1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump (p = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps (p = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews. LIMITATION Blinding of pump therapy was not possible, although an objective primary outcome was used. CONCLUSION Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM. RESEARCH PRIORITY To understand why few patients achieve a HbA1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries. TRIAL REGISTRATION Current Controlled Trials ISRCTN61215213. FUNDING This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 20. See the NIHR Journals Library website for further project information. PMID:28440211

Clinical Evaluation of the Use of a Multifunctional Remotely Controlled Insulin Pump

PubMed Central

Pinget, Michel; Lachgar, Karim; Parkin, Christopher G.; Grulet, Hervé; Guillon-Metz, Françoise; Weissmann, Joerg

2014-01-01

Current insulin pumps now feature advanced functions for calculating insulin dosages, delivering insulin and analyzing data, however, the perceived usefulness of these functions in clinical settings has not been well studied. We assessed the use and patient perceptions of an insulin delivery system (Accu-Chek® Combo, Roche Diagnostics, Mannheim, Germany) that combines an insulin pump and a handheld multifunctional blood glucose meter with integrated remote control functions. This prospective, observational, multicenter study enrolled 74 type 1 diabetes patients within 13 weeks after starting use of the pump system. At 4 to 24 weeks, investigators collected usage data from the latest 14-day period. Seventy-two patients completed the evaluation, aged 39 ± 15 years, diabetes duration 16 ± 13 years, HbA1c 8.3 ± 1.6%. At follow-up, 62 (86.1%) patients used the remote control for ≥50% of all boluses, 20 (27.8%) used the bolus advisor for ≥50% of all boluses, and 42 (58.3%) viewed at least 1 of the e-logbook reports. More than 95% of users appraised the functions as easy-to-use and useful; median scores from VAS (0 = useless to 100 = indispensable) ranged from 72 to 85. A high percentage of study patients used the system’s advanced features, especially the remote control feature for bolusing. Overall, patients assessed the functions as useful and easy to use. Results support the implementation of these smart capabilities in further insulin pump developments. PMID:25107708

Nonmetabolic Complications of Continuous Subcutaneous Insulin Infusion: A Patient Survey

PubMed Central

Yemane, Nardos; Brackenridge, Anna; Pender, Siobhan

2014-01-01

Abstract Background: Little is known about the frequencies and types of nonmetabolic complications occurring in type 1 diabetes patients being treated by modern insulin pump therapy (continuous subcutaneous insulin infusion [CSII]), when recorded by standardized questionnaire rather than clinical experience. Subjects and Methods: A self-report questionnaire was completed by successive subjects with type 1 diabetes attending an insulin pump clinic, and those with a duration of CSII of ≥6 months were selected for analysis (n=92). Questions included pump manufacturer, insulin, infusion set type and duration of use, frequency of infusion set and site problems, pump malfunctions, and patient-related problems such as weight change since starting CSII. Results: Median (range) duration of CSII was 3.3 (0.5–32.0) years, and mean±SD duration of infusion set use was 3.2±0.7 (range 2–6) days. The commonest infusion set problems were kinking (64.1% of subjects) and blockage (54.3%). Blockage was associated with >3 days of use of infusion sets plus lispro insulin in the pump (relative risk [95% confidence interval], 1.71 [1.03–2.85]; P=0.07). The commonest infusion site problem was lipohypertrophy (26.1%), which occurred more often in those with long duration of CSII (4.8 [2.38–9.45] vs. 3.0 [1.50–4.25] years; P=0.01). Pump malfunction had occurred in 48% of subjects (43% in the first year of CSII), with “no delivery,” keypad, and battery problems commonly occurring. Although some patients reported weight gain (34%) and some weight loss (15%) on CSII, most patients (51%) reported no change in weight. Conclusions: Pump, infusion set, and infusion site problems remain common with CSII, even with contemporary technology. PMID:24180294

Safe intravenous administration in pediatrics: A 5-year Pediatric Intensive Care Unit experience with smart pumps.

PubMed

Manrique-Rodríguez, S; Sánchez-Galindo, A C; Fernández-Llamazares, C M; Calvo-Calvo, M M; Carrillo-Álvarez, Á; Sanjurjo-Sáez, M

2016-10-01

To estimate the impact of smart pump implementation in a pediatric intensive care unit in terms of number and type of administration errors intercepted. Observational, prospective study carried out from January 2010 to March 2015 with syringe and great volumen infusion pumps available in the hospital. A tertiary level hospital pediatric intensive care unit. Infusions delivered with infusion pumps in all pediatric intensive care unit patients. Design of a drug library with safety limits for all intravenous drugs prescribed. Users' compliance with drug library as well as number and type of errors prevented were analyzed. Two hundred and eighty-three errors were intercepted during 62 months of study. A high risk drug was involved in 58% of prevented errors, such as adrenergic agonists and antagonists, sedatives, analgesics, neuromuscular blockers, opioids, potassium and insulin. Users' average compliance with the safety software was 84%. Smart pumps implementation has proven effective in intercepting high risk drugs programming errors. These results might be exportable to other critical care units, involving pediatric or adult patients. Interdisciplinary colaboration is key to succeed in this process. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Management of diabetes mellitus: is the pump mightier than the pen?

PubMed

Pickup, John C

2012-02-28

Continuous subcutaneous insulin infusion (CSII, or insulin pump therapy) reduces HbA1c levels and hypoglycaemia in patients with type 1 diabetes mellitus (T1DM) compared with multiple daily insulin injections (MDI). The greatest reduction in HbA(1c) levels with CSII occurs in patients with the worst glycaemic control; therefore, the most appropriate and cost-effective use of CSII in adults with T1DM is in those who have continued, elevated HbA(1c) levels or disabling hypoglycaemic episodes with MDI (including the use of long-acting insulin analogues and structured patient education). The disadvantages of CSII include higher costs than MDI and the risk of ketosis in the event of pump failure. In children with T1DM, CSII may be used when MDI is considered impractical or inappropriate. Pumps are not generally recommended for patients with type 2 diabetes mellitus but may improve control in some subgroups. A new generation of smaller insulin infusion pumps with an integrated cannula, called patch pumps, could improve uptake of CSII in general. The important clinical question is not whether CSII is more efficacious than MDI in general adult T1DM, but whether CSII further improves glycaemic control when this control continues to be poor with MDI, and evidence exists that in most cases it does.

Portable insulin infusion pumps as an alternative means of insulin delivery in type I diabetes. Report on 11 patients.

PubMed

Distiller, L A

1983-03-26

In many cases of type I diabetes it is extremely difficult to maintain adequate long-term diabetic control. Over the last decade a better understanding has been gained of the relationship between hyperglycaemia and the onset of diabetic microvascular disease. Because of this new techniques are being developed to improve diabetic control; one of these is the use of portable 'open loop' insulin infusion pumps. The results achieved in the first 11 patients to use the Auto-Syringe AS-6C insulin infusion pump on an outpatient basis for longer than 4 months are described. A highly significant improvement in fasting blood glucose levels, 2-hour postprandial blood glucose levels, mean blood glucose levels, glycosylated haemoglobin levels and mean glycaemic excursions was noted in all patients. No cutaneous complications developed despite the use of indwelling subcutaneous needles for up to 4 days at a time. Patient acceptability was excellent and none of the patients had any problems in adapting to 24-hour pump use. The importance of correct patient selection and continuous home blood glucose monitoring is stressed. Insulin infusion pumps can provide an alternative and highly efficacious means of maintaining excellent diabetic control in a select group of type 1 diabetics. However, it is essential that the physician be trained in the use of these pumps and that adequate back-up services are available.

Insulin pump use and glycemic control in adolescents with type 1 diabetes: Predictors of change in method of insulin delivery across two years.

PubMed

Wong, Jenise C; Dolan, Lawrence M; Yang, Tony T; Hood, Korey K

2015-12-01

Few studies have explored durability of insulin pump use, and none have explored the link between depression and pump discontinuation. To examine the relationship between depressive symptoms [measured by the Children's Depression Inventory (CDI)], method of insulin delivery, and hemoglobin A1c (A1c), mixed models were used with data from 150 adolescents with type 1 diabetes (T1D) and visits every 6 months for 2 years. Of the 63% who used a pump, compared with multiple daily injections (MDI) at baseline, there were higher proportions who were non-minorities, had caregivers with a college degree, private insurance, and two caregivers in the home (p ≤ 0.01). After adjusting for time, sex, age, T1D duration, frequency of blood glucose monitoring, ethnicity, insurance, and caregiver number and education, baseline pump use was associated with -0.79% lower mean A1c [95% confidence interval (CI): -1.48, -0.096; p = 0.03]. For those using a pump at baseline, but switching to MDI during the study (n = 9), mean A1c was 1.38% higher (95% CI: 0.68, 2.08; p < 0.001) than that for those who did not switch method of delivery. A 10-point increase in CDI was associated with a 0.39% increase in A1c (95% CI: 0.16, 0.61; p = 0.001), independent of pump use. Regarding the temporal relationship between CDI score and changing method of insulin delivery, prior higher CDI score was associated with switching from pump to MDI (odds ratio = 1.21; 95% CI: 1.05, 1.39; p = 0.007). Clinicians should be aware of the associations between depressive symptoms, change in insulin delivery method, and the effect on glycemic control. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Improving the Computational Effort of Set-Inversion-Based Prandial Insulin Delivery for Its Integration in Insulin Pumps

PubMed Central

León-Vargas, Fabian; Calm, Remei; Bondia, Jorge; Vehí, Josep

2012-01-01

Objective Set-inversion-based prandial insulin delivery is a new model-based bolus advisor for postprandial glucose control in type 1 diabetes mellitus (T1DM). It automatically coordinates the values of basal–bolus insulin to be infused during the postprandial period so as to achieve some predefined control objectives. However, the method requires an excessive computation time to compute the solution set of feasible insulin profiles, which impedes its integration into an insulin pump. In this work, a new algorithm is presented, which reduces computation time significantly and enables the integration of this new bolus advisor into current processing features of smart insulin pumps. Methods A new strategy was implemented that focused on finding the combined basal–bolus solution of interest rather than an extensive search of the feasible set of solutions. Analysis of interval simulations, inclusion of physiological assumptions, and search domain contractions were used. Data from six real patients with T1DM were used to compare the performance between the optimized and the conventional computations. Results In all cases, the optimized version yielded the basal–bolus combination recommended by the conventional method and in only 0.032% of the computation time. Simulations show that the mean number of iterations for the optimized computation requires approximately 3.59 s at 20 MHz processing power, in line with current features of smart pumps. Conclusions A computationally efficient method for basal–bolus coordination in postprandial glucose control has been presented and tested. The results indicate that an embedded algorithm within smart insulin pumps is now feasible. Nonetheless, we acknowledge that a clinical trial will be needed in order to justify this claim. PMID:23294789

Severe hyperkalaemia and ketoacidosis during routine treatment with an insulin pump.

PubMed Central

Knight, G; Jennings, A M; Boulton, A J; Tomlinson, S; Ward, J D

1985-01-01

During a feasibility study of the use of insulin pumps to treat diabetes ketoacidosis occurred at a rate of 0.14 episodes/patient/year in the first year but was lower in subsequent years. A case of cardiac arrest secondary to hyperkalaemia during ketoacidosis occurred in a patient treated with a pump. The mean (SD) serum potassium concentration on presentation to hospital with ketoacidosis was significantly higher in patients treated with a pump (5.7 (1.1) mmol(mEq)/l) than those treated with conventional injections of insulin (4.9(0.9) mmol/l; p less than 0.01). The high rate of ketoacidosis and raised serum potassium concentrations during treatment with the pump creates doubt about the use of this treatment as an alternative regimen for large numbers of patients in a busy diabetic clinic. PMID:3926198

Sensor-Augmented Insulin Pumps and Hypoglycemia Prevention in Type 1 Diabetes

PubMed Central

Steineck, Isabelle; Ranjan, Ajenthen; Nørgaard, Kirsten; Schmidt, Signe

2016-01-01

Hypoglycemia can lead to seizures, unconsciousness, or death. Insulin pump treatment reduces the frequency of severe hypoglycemia compared with multiple daily injections treatment. The addition of a continuous glucose monitor, so-called sensor-augmented pump (SAP) treatment, has the potential to further limit the duration and severity of hypoglycemia as the system can detect and in some systems act on impending and prevailing low blood glucose levels. In this narrative review we summarize the available knowledge on SAPs with and without automated insulin suspension, in relation to hypoglycemia prevention. We present evidence from randomized trials, observational studies, and meta-analyses including nonpregnant individuals with type 1 diabetes mellitus. We also outline concerns regarding SAPs with and without automated insulin suspension. There is evidence that SAP treatment reduces episodes of moderate and severe hypoglycemia compared with multiple daily injections plus self-monitoring of blood glucose. There is some evidence that SAPs both with and without automated suspension reduces the frequency of severe hypoglycemic events compared with insulin pumps without continuous glucose monitoring. PMID:28264173

Comparison of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy for glycaemic control in patients with type 1 diabetes: an open-label randomised controlled crossover trial.

PubMed

Haidar, Ahmad; Legault, Laurent; Messier, Virginie; Mitre, Tina Maria; Leroux, Catherine; Rabasa-Lhoret, Rémi

2015-01-01

The artificial pancreas is an emerging technology for the treatment of type 1 diabetes and two configurations have been proposed: single-hormone (insulin alone) and dual-hormone (insulin and glucagon). We aimed to delineate the usefulness of glucagon in the artificial pancreas system. We did a randomised crossover trial of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy (continuous subcutaneous insulin infusion) in participants aged 12 years or older with type 1 diabetes. Participants were assigned in a 1:1:1:1:1:1 ratio with blocked randomisation to the three interventions and attended a research facility for three 24-h study visits. During visits when the patient used the single-hormone artificial pancreas, insulin was delivered based on glucose sensor readings and a predictive dosing algorithm. During dual-hormone artificial pancreas visits, glucagon was also delivered during low or falling glucose. During conventional insulin pump therapy visits, patients received continuous subcutaneous insulin infusion. The study was not masked. The primary outcome was the time for which plasma glucose concentrations were in the target range (4·0-10·0 mmol/L for 2 h postprandially and 4·0-8·0 mmol/L otherwise). Hypoglycaemic events were defined as plasma glucose concentration of less than 3·3 mmol/L with symptoms or less than 3·0 mmol/L irrespective of symptoms. Analysis was by modified intention to treat, in which we included data for all patients who completed at least two visits. A p value of less than 0·0167 (0·05/3) was regarded as significant. This trial is registered with ClinicalTrials.gov, number NCT01754337. The mean proportion of time spent in the plasma glucose target range over 24 h was 62% (SD 18), 63% (18), and 51% (19) with single-hormone artificial pancreas, dual-hormone artificial pancreas, and conventional insulin pump therapy, respectively. The mean difference in time spent in the target range between single-hormone artificial pancreas and conventional insulin pump therapy was 11% (17; p=0·002) and between dual-hormone artificial pancreas and conventional insulin pump therapy was 12% (21; p=0·00011). There was no difference (15; p=0·75) in the proportion of time spent in the target range between the single-hormone and dual-hormone artificial pancreas systems. There were 52 hypoglycaemic events with conventional insulin pump therapy (12 of which were symptomatic), 13 with the single-hormone artificial pancreas (five of which were symptomatic), and nine with the dual-hormone artificial pancreas (0 of which were symptomatic); the number of nocturnal hypoglycaemic events was 13 (0 symptomatic), 0, and 0, respectively. Single-hormone and dual-hormone artificial pancreas systems both provided better glycaemic control than did conventional insulin pump therapy. The single-hormone artificial pancreas might be sufficient for hypoglycaemia-free overnight glycaemic control. Canadian Diabetes Association; Fondation J A De Sève; Juvenile Diabetes Research Foundation; and Medtronic. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sensor-augmented pump therapy lowers HbA(1c) in suboptimally controlled Type 1 diabetes; a randomized controlled trial.

PubMed

Hermanides, J; Nørgaard, K; Bruttomesso, D; Mathieu, C; Frid, A; Dayan, C M; Diem, P; Fermon, C; Wentholt, I M E; Hoekstra, J B L; DeVries, J H

2011-10-01

To investigate the efficacy of sensor-augmented pump therapy vs. multiple daily injection therapy in patients with suboptimally controlled Type 1 diabetes. In this investigator-initiated multi-centre trial (the Eurythmics Trial) in eight outpatient centres in Europe, we randomized 83 patients with Type 1 diabetes (40 women) currently treated with multiple daily injections, age 18-65 years and HbA(1c) ≥ 8.2% (≥ 66 mmol/mol) to 26 weeks of treatment with either a sensor-augmented insulin pump (n = 44) (Paradigm(®) REAL-Time) or continued with multiple daily injections (n = 39). Change in HbA(1c) between baseline and 26 weeks, sensor-derived endpoints and patient-reported outcomes were assessed. The trial was completed by 43/44 (98%) patients in the sensor-augmented insulin pump group and 35/39 (90%) patients in the multiple daily injections group. Mean HbA(1c) at baseline and at 26 weeks changed from 8.46% (SD 0.95) (69 mmol/mol) to 7.23% (SD 0.65) (56 mmol/mol) in the sensor-augmented insulin pump group and from 8.59% (SD 0.82) (70 mmol/mol) to 8.46% (SD 1.04) (69 mmol/mol) in the multiple daily injections group. Mean difference in change in HbA(1c) after 26 weeks was -1.21% (95% confidence interval -1.52 to -0.90, P < 0.001) in favour of the sensor-augmented insulin pump group. This was achieved without an increase in percentage of time spent in hypoglycaemia: between-group difference 0.0% (95% confidence interval -1.6 to 1.7, P = 0.96). There were four episodes of severe hypoglycaemia in the sensor-augmented insulin pump group and one episode in the multiple daily injections group (P = 0.21). Problem Areas in Diabetes and Diabetes Treatment Satisfaction Questionnaire scores improved in the sensor-augmented insulin pump group. Sensor augmented pump therapy effectively lowers HbA(1c) in patients with Type 1 diabetes suboptimally controlled with multiple daily injections. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

Insulin pump risks and benefits: a clinical appraisal of pump safety standards, adverse event reporting and research needs. A joint statement of the European Association for the Study of Diabetes and the American Diabetes Association Diabetes Technology Working Group.

PubMed

Heinemann, Lutz; Fleming, G Alexander; Petrie, John R; Holl, Reinhard W; Bergenstal, Richard M; Peters, Anne L

2015-05-01

Insulin pump therapy, also known as continuous subcutaneous insulin infusion (CSII), is an important and evolving form of insulin delivery, which is mainly used for people with type 1 diabetes. However, even with modern insulin pumps, errors of insulin infusion can occur due to pump failure, insulin infusion set (IIS) blockage, infusion site problems, insulin stability issues, user error or a combination of these. Users are therefore exposed to significant and potentially fatal hazards: interruption of insulin infusion can result in hyperglycaemia and ketoacidosis; conversely, delivery of excessive insulin can cause severe hypoglycaemia. Nevertheless, the available evidence on the safety and efficacy of CSII remains limited. The European Association for the Study of Diabetes (EASD) and American Diabetes Association (ADA) have therefore joined forces to review the systems in place for evaluating the safety of pumps from a clinical perspective. We found that useful information held by the manufacturing companies is not currently shared in a sufficiently transparent manner. Public availability of adverse event (AE) reports on the US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database is potentially a rich source of safety information but is insufficiently utilised due to the current configuration of the system; the comparable database in Europe (European Databank on Medical Devices, EUDAMED) is not publicly accessible. Many AEs appear to be attributable to human factors and/or user error, but the extent to which manufacturing companies are required by regulators to consider the interactions of users with the technical features of their products is limited. The clinical studies required by regulators prior to marketing are small and over-reliant on bench testing in relation to 'predicate' products. Once a pump is available on the market, insufficient data are made publicly available on its long-term use in a real-world setting; such data could provide vital information to help healthcare teams to educate and support users, and thereby prevent AEs. As well as requiring more from the manufacturing companies, we call for public funding of more research addressing clinically important questions in relation to pump therapy: both observational studies and clinical trials. At present there are significant differences in the regulatory systems between the USA and European Union at both pre- and post-marketing stages; improvements in the European system are more urgently required. This statement concludes with a series of recommended specific actions for 'meknovigilance' (i.e. a standardised safety approach to technology) which could be implemented to address the shortcomings we highlight.

Prevention of Insulin-Induced Hypoglycemia in Type 1 Diabetes with Predictive Low Glucose Management System.

PubMed

Abraham, Mary B; de Bock, Martin; Paramalingam, Nirubasini; O'Grady, Michael J; Ly, Trang T; George, Carly; Roy, Anirban; Spital, Glenn; Karula, Sophy; Heels, Kristine; Gebert, Rebecca; Fairchild, Jan M; King, Bruce R; Ambler, Geoffrey R; Cameron, Fergus; Davis, Elizabeth A; Jones, Timothy W

2016-07-01

Sensor-augmented pump therapy (SAPT) with algorithms to predict impending low blood glucose and suspend insulin delivery has the potential to reduce hypoglycemia exposure. The aim of this study was to determine whether predictive low glucose management (PLGM) system is effective in preventing insulin-induced hypoglycemia in controlled experiments. Two protocols were used to induce hypoglycemia in an in-clinic environment. (A) Insulin bolus: Insulin was administered as a manual bolus through the pump. (B) Increased basal insulin: Hypoglycemia was induced by increasing basal rates overnight to 180%. For both protocols, participants were randomized and studied on 2 separate days; a control day with SAPT alone and an intervention day with SAPT and PLGM activated. The predictive algorithm was programmed to suspend basal insulin infusion when sensor glucose was predicted to be <80 mg/dL in 30 min. The primary outcome was the requirement for hypoglycemia treatment (symptomatic hypoglycemia or plasma glucose <50 mg/dL) and was compared in both control and intervention arms. With insulin bolus, 24/28 participants required hypoglycemia treatment with SAPT alone compared to 5/28 participants when PLGM was activated (P ≤ 0.001). With increased basal rates, all the eight SAPT-alone participants required treatment for hypoglycemia compared to only one with SAPT and PLGM. There was no post pump-suspend hyperglycemia with insulin bolus (P = 0.4) or increased basal rates (P = 0.69) in participants with 2-h pump suspension on intervention days. SAPT with PLGM reduced the requirement for hypoglycemia treatment following insulin-induced hypoglycemia in an in-clinic setting.

[Progress in the development of insulin pumps and their advanced automatic functions].

PubMed

Prázný, Martin

2015-04-01

Patients with type 1 diabetes are exposed to permanent burden consisting of careful glucose self-monitoring and precise insulin dosage based on measured glucose values, carbohydrates content in the food and both planned and non-planned physical activity. Erroneous insulin dosing causes frequent both hypoglycemia and hyperglycemia. Hypoglycemia is, however, the most clinically significant complication limiting the optimal diabetes control. Automatic features for insulin dosage integrated in insulin pumps are thus very important. Low glucose suspend (LGS) and Predictive Low Glucose Management (PLGM) use glucose sensor values to prevent hypoglycemia, shorten the time spent in hypoglycemic range and present further step forward to fully closed-loop system of insulin treatment.

High precision innovative micropump for artificial pancreas

NASA Astrophysics Data System (ADS)

Chappel, E.; Mefti, S.; Lettieri, G.-L.; Proennecke, S.; Conan, C.

2014-03-01

The concept of artificial pancreas, which comprises an insulin pump, a continuous glucose meter and a control algorithm, is a major step forward in managing patient with type 1 diabetes mellitus. The stability of the control algorithm is based on short-term precision micropump to deliver rapid-acting insulin and to specific integrated sensors able to monitor any failure leading to a loss of accuracy. Debiotech's MEMS micropump, based on the membrane pump principle, is made of a stack of 3 silicon wafers. The pumping chamber comprises a pillar check-valve at the inlet, a pumping membrane which is actuated against stop limiters by a piezo cantilever, an anti-free-flow outlet valve and a pressure sensor. The micropump inlet is tightly connected to the insulin reservoir while the outlet is in direct communication with the patient skin via a cannula. To meet the requirement of a pump dedicated to closed-loop application for diabetes care, in addition to the well-controlled displacement of the pumping membrane, the high precision of the micropump is based on specific actuation profiles that balance effect of pump elasticity in low-consumption push-pull mode.

Keeping Up with the Diabetes Technology: 2016 Endocrine Society Guidelines of Insulin Pump Therapy and Continuous Glucose Monitor Management of Diabetes.

PubMed

Galderisi, Alfonso; Schlissel, Elise; Cengiz, Eda

2017-09-23

Decades after the invention of insulin pump, diabetes management has encountered a technology revolution with the introduction of continuous glucose monitoring, sensor-augmented insulin pump therapy and closed-loop/artificial pancreas systems. In this review, we discuss the significance of the 2016 Endocrine Society Guidelines for insulin pump therapy and continuous glucose monitoring and summarize findings from relevant diabetes technology studies that were conducted after the publication of the 2016 Endocrine Society Guidelines. The 2016 Endocrine Society Guidelines have been a great resource for clinicians managing diabetes in this new era of diabetes technology. There is good body of evidence indicating that using diabetes technology systems safely tightens glycemic control while managing both type 1 and type 2 diabetes. The first-generation diabetes technology systems will evolve as we gain more experience and collaboratively work to improve them with an ultimate goal of keeping people with diabetes complication and burden-free until the cure for diabetes becomes a reality.

UK service level audit of insulin pump therapy in paediatrics.

PubMed

Ghatak, A; Paul, P; Hawcutt, D B; White, H D; Furlong, N J; Saunders, S; Morrison, G; Langridge, P; Weston, P J

2015-12-01

To conduct an audit of insulin pump therapy in the UK after the issue of guidelines for the use of continuous subcutaneous insulin infusion by NICE in 2008 (Technology Appraisal 151). All centres in the UK, providing pump services to children and young people were invited to participate in an online audit. Audit metrics were aligned to NICE Technology Appraisal 151 and an electronic data collection tool was used. Of the 176 UK centres identified as providing pump services, 166 (94.3%) participated in the study. A total of 5094 children and young people were identified as using continuous subcutaneous insulin infusion (19% of all paediatric patients with Type 1 diabetes), with a median (range) of 16.9 (0.67-69.4)% per centre. Units had a median of 0.58 consultant sessions, 0.43 full-time equivalent diabetic specialist nurses, and 0.1 full-time equivalent dieticians delivering the pump service. The majority of this time was not formally funded. Families could access 24-h clinical and technical support (83% units), although the delivery varied between consultant, diabetic specialist nurse and company representatives. Only 53% of units ran, or accessed, structured education programmes for continuous subcutaneous insulin infusion use. Most units (86%) allowed continuous subcutaneous insulin infusion use for paediatric inpatients, but only 56% had written guidelines for this scenario. Nine percent of units had encountered funding refusal for a patient fulfilling NICE (Technology Appraisal 151) criteria. The number of children and young people on continuous subcutaneous insulin infusion therapy is consistent with numbers estimated by NICE. There is a worrying lack of funded healthcare professional time. The audit also identified gaps in the provision of structured education and absence of written inpatient guidelines. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

Day-and-Night Hybrid Closed-Loop Insulin Delivery in Adolescents With Type 1 Diabetes: A Free-Living, Randomized Clinical Trial.

PubMed

Tauschmann, Martin; Allen, Janet M; Wilinska, Malgorzata E; Thabit, Hood; Stewart, Zoë; Cheng, Peiyao; Kollman, Craig; Acerini, Carlo L; Dunger, David B; Hovorka, Roman

2016-07-01

To evaluate feasibility, safety, and efficacy of day-and-night hybrid closed-loop insulin delivery in adolescents with type 1 diabetes under free-living conditions without remote monitoring or supervision. In an open-label, randomized, free-living, crossover study design, 12 adolescents receiving insulin pump therapy (mean [±SD] age 15.4 ± 2.6 years; HbA1c 8.3 ± 0.9%; duration of diabetes 8.2 ± 3.4 years) underwent two 7-day periods of sensor-augmented insulin pump therapy or hybrid closed-loop insulin delivery without supervision or remote monitoring. During the closed-loop insulin delivery, a model predictive algorithm automatically directed insulin delivery between meals and overnight; prandial boluses were administered by participants using a bolus calculator. The proportion of time when the sensor glucose level was in the target range (3.9-10 mmol/L) was increased during closed-loop insulin delivery compared with sensor-augmented pump therapy (72 vs. 53%, P < 0.001; primary end point), the mean glucose concentration was lowered (8.7 vs. 10.1 mmol/L, P = 0.028), and the time spent above the target level was reduced (P = 0.005) without changing the total daily insulin amount (P = 0.55). The time spent in the hypoglycemic range was low and comparable between interventions. Unsupervised day-and-night hybrid closed-loop insulin delivery at home is feasible and safe in young people with type 1 diabetes. Compared with sensor-augmented insulin pump therapy, closed-loop insulin delivery may improve glucose control without increasing the risk of hypoglycemia in adolescents with suboptimally controlled type 1 diabetes. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Threshold-based insulin-pump interruption for reduction of hypoglycemia.

PubMed

Bergenstal, Richard M; Klonoff, David C; Garg, Satish K; Bode, Bruce W; Meredith, Melissa; Slover, Robert H; Ahmann, Andrew J; Welsh, John B; Lee, Scott W; Kaufman, Francine R

2013-07-18

The threshold-suspend feature of sensor-augmented insulin pumps is designed to minimize the risk of hypoglycemia by interrupting insulin delivery at a preset sensor glucose value. We evaluated sensor-augmented insulin-pump therapy with and without the threshold-suspend feature in patients with nocturnal hypoglycemia. We randomly assigned patients with type 1 diabetes and documented nocturnal hypoglycemia to receive sensor-augmented insulin-pump therapy with or without the threshold-suspend feature for 3 months. The primary safety outcome was the change in the glycated hemoglobin level. The primary efficacy outcome was the area under the curve (AUC) for nocturnal hypoglycemic events. Two-hour threshold-suspend events were analyzed with respect to subsequent sensor glucose values. A total of 247 patients were randomly assigned to receive sensor-augmented insulin-pump therapy with the threshold-suspend feature (threshold-suspend group, 121 patients) or standard sensor-augmented insulin-pump therapy (control group, 126 patients). The changes in glycated hemoglobin values were similar in the two groups. The mean AUC for nocturnal hypoglycemic events was 37.5% lower in the threshold-suspend group than in the control group (980 ± 1200 mg per deciliter [54.4 ± 66.6 mmol per liter] × minutes vs. 1568 ± 1995 mg per deciliter [87.0 ± 110.7 mmol per liter] × minutes, P<0.001). Nocturnal hypoglycemic events occurred 31.8% less frequently in the threshold-suspend group than in the control group (1.5 ± 1.0 vs. 2.2 ± 1.3 per patient-week, P<0.001). The percentages of nocturnal sensor glucose values of less than 50 mg per deciliter (2.8 mmol per liter), 50 to less than 60 mg per deciliter (3.3 mmol per liter), and 60 to less than 70 mg per deciliter (3.9 mmol per liter) were significantly reduced in the threshold-suspend group (P<0.001 for each range). After 1438 instances at night in which the pump was stopped for 2 hours, the mean sensor glucose value was 92.6 ± 40.7 mg per deciliter (5.1 ± 2.3 mmol per liter). Four patients (all in the control group) had a severe hypoglycemic event; no patients had diabetic ketoacidosis. This study showed that over a 3-month period the use of sensor-augmented insulin-pump therapy with the threshold-suspend feature reduced nocturnal hypoglycemia, without increasing glycated hemoglobin values. (Funded by Medtronic MiniMed; ASPIRE ClinicalTrials.gov number, NCT01497938.).

Evaluation of Pump Discontinuation and Associated Factors in the T1D Exchange Clinic Registry

PubMed Central

Wong, Jenise C.; Boyle, Claire; DiMeglio, Linda A.; Mastrandrea, Lucy D.; Abel, Kimber-Lee; Cengiz, Eda; Cemeroglu, Pinar A.; Aleppo, Grazia; Largay, Joseph F.; Foster, Nicole C.; Beck, Roy W.; Adi, Saleh

2017-01-01

Background: The objectives of this study were to examine factors associated with insulin pump discontinuation among children and adults followed longitudinally for 1 year in the multicenter T1D Exchange clinic registry, and to provide participant-reported reasons for stopping pump therapy. Methods: We longitudinally followed 8935 participants of all ages using an insulin pump at the time of registry enrollment. Logistic regressions were used to identify demographic and clinical factors associated with pump discontinuation. Pump discontinuation was self-reported by participants on a first annual follow-up survey. Results: The overall frequency of pump discontinuation was 3%. Discontinuation was higher in adolescents (4%) and young adults (4%) than in younger children (3%) or older adults (1%). In multivariate analysis of children between 6 and <13 and 13 and <18 years, participants who discontinued pump use were more likely to have higher HbA1c levels at baseline (adjusted P < .001 for both). The top participant-reported reasons for discontinuing the pump included problems with wearability (57%), disliking the pump or feeling anxious (44%), and problems with glycemic control (30%). Conclusions: In T1D Exchange registry participants, insulin pump discontinuation is uncommon, but more prevalent among adolescents and young adults, and youth with poor glycemic control. Given the known benefits of pump therapy, these populations should be targeted for support and education on troubleshooting pump use. Common reasons for discontinuation should also be considered in future device design and technological improvement. PMID:27595711

Evaluation of Pump Discontinuation and Associated Factors in the T1D Exchange Clinic Registry.

PubMed

Wong, Jenise C; Boyle, Claire; DiMeglio, Linda A; Mastrandrea, Lucy D; Abel, Kimber-Lee; Cengiz, Eda; Cemeroglu, Pinar A; Aleppo, Grazia; Largay, Joseph F; Foster, Nicole C; Beck, Roy W; Adi, Saleh

2017-03-01

The objectives of this study were to examine factors associated with insulin pump discontinuation among children and adults followed longitudinally for 1 year in the multicenter T1D Exchange clinic registry, and to provide participant-reported reasons for stopping pump therapy. We longitudinally followed 8935 participants of all ages using an insulin pump at the time of registry enrollment. Logistic regressions were used to identify demographic and clinical factors associated with pump discontinuation. Pump discontinuation was self-reported by participants on a first annual follow-up survey. The overall frequency of pump discontinuation was 3%. Discontinuation was higher in adolescents (4%) and young adults (4%) than in younger children (3%) or older adults (1%). In multivariate analysis of children between 6 and <13 and 13 and <18 years, participants who discontinued pump use were more likely to have higher HbA1c levels at baseline (adjusted P < .001 for both). The top participant-reported reasons for discontinuing the pump included problems with wearability (57%), disliking the pump or feeling anxious (44%), and problems with glycemic control (30%). In T1D Exchange registry participants, insulin pump discontinuation is uncommon, but more prevalent among adolescents and young adults, and youth with poor glycemic control. Given the known benefits of pump therapy, these populations should be targeted for support and education on troubleshooting pump use. Common reasons for discontinuation should also be considered in future device design and technological improvement.

Insulin Patch Pumps: Their Development and Future in Closed-Loop Systems

PubMed Central

Bohannon, Nancy J.V.

2010-01-01

Abstract Steady progress is being made toward the development of a so-called “artificial pancreas,” which may ultimately be a fully automated, closed-loop, glucose control system comprising a continuous glucose monitor, an insulin pump, and a controller. The controller will use individualized algorithms to direct delivery of insulin without user input. A major factor propelling artificial pancreas development is the substantial incidence of—and attendant patient, parental, and physician concerns about—hypoglycemia and extreme hyperglycemia associated with current means of insulin delivery for type 1 diabetes mellitus (T1DM). A successful fully automated artificial pancreas would likely reduce the frequency of and anxiety about hypoglycemia and marked hyperglycemia. Patch-pump systems (“patch pumps”) are likely to be used increasingly in the control of T1DM and may be incorporated into the artificial pancreas systems of tomorrow. Patch pumps are free of tubing, small, lightweight, and unobtrusive. This article describes features of patch pumps that have been approved for U.S. marketing or are under development. Included in the review is an introduction to control algorithms driving insulin delivery, particularly the two major types: proportional integrative derivative and model predictive control. The use of advanced algorithms in the clinical development of closed-loop systems is reviewed along with projected next steps in artificial pancreas development. PMID:20515308

Model-Based Sensor-Augmented Pump Therapy

PubMed Central

Grosman, Benyamin; Voskanyan, Gayane; Loutseiko, Mikhail; Roy, Anirban; Mehta, Aloke; Kurtz, Natalie; Parikh, Neha; Kaufman, Francine R.; Mastrototaro, John J.; Keenan, Barry

2013-01-01

Background In insulin pump therapy, optimization of bolus and basal insulin dose settings is a challenge. We introduce a new algorithm that provides individualized basal rates and new carbohydrate ratio and correction factor recommendations. The algorithm utilizes a mathematical model of blood glucose (BG) as a function of carbohydrate intake and delivered insulin, which includes individualized parameters derived from sensor BG and insulin delivery data downloaded from a patient’s pump. Methods A mathematical model of BG as a function of carbohydrate intake and delivered insulin was developed. The model includes fixed parameters and several individualized parameters derived from the subject’s BG measurements and pump data. Performance of the new algorithm was assessed using n = 4 diabetic canine experiments over a 32 h duration. In addition, 10 in silico adults from the University of Virginia/Padova type 1 diabetes mellitus metabolic simulator were tested. Results The percentage of time in glucose range 80–180 mg/dl was 86%, 85%, 61%, and 30% using model-based therapy and [78%, 100%] (brackets denote multiple experiments conducted under the same therapy and animal model), [75%, 67%], 47%, and 86% for the control experiments for dogs 1 to 4, respectively. The BG measurements obtained in the simulation using our individualized algorithm were in 61–231 mg/dl min–max envelope, whereas use of the simulator’s default treatment resulted in BG measurements 90–210 mg/dl min–max envelope. Conclusions The study results demonstrate the potential of this method, which could serve as a platform for improving, facilitating, and standardizing insulin pump therapy based on a single download of data. PMID:23567006

A Methodology to Compare Insulin Dosing Recommendations in Real-Life Settings.

PubMed

Groat, Danielle; Grando, Maria A; Thompson, Bithika; Neto, Pedro; Soni, Hiral; Boyle, Mary E; Bailey, Marilyn; Cook, Curtiss B

2017-11-01

We propose a methodology to analyze complex real-life glucose data in insulin pump users. Patients with type 1 diabetes (T1D) on insulin pumps were recruited from an academic endocrinology practice. Glucose data, insulin bolus (IB) amounts, and self-reported alcohol consumption and exercise events were collected for 30 days. Rules were developed to retrospectively compare IB recommendations from the insulin pump bolus calculator (IPBC) against recommendations from a proposed decision aid (PDA) and for assessing the PDA's recommendation for exercise and alcohol. Data from 15 participants were analyzed. When considering instances where glucose was below target, the PDA recommended a smaller dose in 14%, but a larger dose in 13% and an equivalent IB in 73%. For glucose levels at target, the PDA suggested an equivalent IB in 58% compared to the subject's IPBC, but higher doses in 20% and lower in 22%. In events where postprandial glucose was higher than target, the PDA suggested higher doses in 25%, lower doses in 13%, and equivalent doses in 62%. In 64% of all alcohol events the PDA would have provided appropriate advice. In 75% of exercise events, the PDA appropriately advised an IB, a carbohydrate snack, or neither. This study provides a methodology to systematically analyze real-life data generated by insulin pumps and allowed a preliminary analysis of the performance of the PDA for insulin dosing. Further testing of the methodological approach in a broader diabetes population and prospective testing of the PDA are needed.

AADE position statement: education for continuous subcutaneous insulin infusion pump users. American Association of Diabetes Educators.

PubMed

1997-01-01

Successful implementation of CSII requires a motivated patient with a range of technical skills and self-management capabilities. Patients develop this expertise through an ongoing program of education and the support that a healthcare team knowledgeable in insulin pump therapy can provide.

Insulin pump risks and benefits: a clinical appraisal of pump safety standards, adverse event reporting, and research needs: a joint statement of the European Association for the Study of Diabetes and the American Diabetes Association Diabetes Technology Working Group.

PubMed

Heinemann, Lutz; Fleming, G Alexander; Petrie, John R; Holl, Reinhard W; Bergenstal, Richard M; Peters, Anne L

2015-04-01

Insulin pump therapy, also known as continuous subcutaneous insulin infusion (CSII), is an important and evolving form of insulin delivery, which is mainly used for people with type 1 diabetes. However, even with modern insulin pumps, errors of insulin infusion can occur due to pump failure, insulin infusion set (IIS) blockage, infusion site problems, insulin stability issues, user error, or a combination of these. Users are therefore exposed to significant and potentially fatal hazards: interruption of insulin infusion can result in hyperglycemia and ketoacidosis; conversely, delivery of excessive insulin can cause severe hypoglycemia. Nevertheless, the available evidence on the safety and efficacy of CSII remains limited. The European Association for the Study of Diabetes (EASD) and the American Diabetes Association (ADA) have therefore joined forces to review the systems in place for evaluating the safety of pumps from a clinical perspective. We found that useful information held by the manufacturing companies is not currently shared in a sufficiently transparent manner. Public availability of adverse event (AE) reports on the US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database is potentially a rich source of safety information but is insufficiently utilized due to the current configuration of the system; the comparable database in Europe (European Databank on Medical Devices [EUDAMED]) is not publicly accessible. Many AEs appear to be attributable to human factors and/or user error, but the extent to which manufacturing companies are required by regulators to consider the interactions of users with the technical features of their products is limited. The clinical studies required by regulators prior to marketing are small and over-reliant on bench testing in relation to "predicate" products. Once a pump is available on the market, insufficient data are made publicly available on its long-term use in a real-world setting; such data could provide vital information to help health care teams to educate and support users and thereby prevent AEs. As well as requiring more from the manufacturing companies, we call for public funding of more research addressing clinically important questions in relation to pump therapy: both observational studies and clinical trials. At present, there are significant differences in the regulatory systems between the US and European Union at both pre- and postmarketing stages; improvements in the European system are more urgently required. This statement concludes with a series of recommended specific actions for "meknovigilance" (i.e., a standardized safety approach to technology) that could be implemented to address the shortcomings we highlight. © 2015 by the American Diabetes Association and Springer-Verlag. Copying with attribution allowed for any noncommercial use of the work.

Tolerance of centrifuge-simulated suborbital spaceflight in subjects with implanted insulin pumps.

PubMed

Levin, Dana R; Blue, Rebecca S; Castleberry, Tarah L; Vanderploeg, James M

2015-04-01

With commercial spaceflight comes the possibility of spaceflight participants (SFPs) with significant medical conditions. Those with previously untested medical conditions, such as diabetes mellitus (DM) and the use of indwelling medical devices, represent a unique challenge. It is unclear how SFPs with such devices will react to the stresses of spaceflight. This case report describes two subjects with Type I DM using insulin pumps who underwent simulated dynamic phases of spaceflight via centrifuge G force exposure. Two Type I diabetic subjects with indwelling Humalog insulin pumps, a 23-yr-old man averaging 50 u of Humalog daily and a 27-yr-old man averaging 60 u of Humalog daily, underwent seven centrifuge runs over 48 h. Day 1 consisted of two +Gz runs (peak = +3.5 Gz, run 2) and two +Gx runs (peak = +6.0 Gx, run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +Gx and +Gz). Data collected included blood pressure, electrocardiogram, pulse oximetry, neurovestibular evaluation, and questionnaires regarding motion sickness, disorientation, greyout, and other symptoms. Neither subject experienced adverse clinical responses to the centrifuge exposure. Both maintained blood glucose levels between 110-206 mg · dl(-1). Potential risks to SFPs with insulin pump dependent DM include hypo/hyperglycemia, pump damage, neurovestibular dysfunction, skin breakdown, and abnormal stress responses. A search of prior literature did not reveal any previous studies of individuals with DM on insulin pumps exposed to prolonged accelerations. These cases suggest that individuals with conditions dependent on continuous medication delivery might tolerate the accelerations anticipated for commercial spaceflight.

A cost-effectiveness analysis of sensor-augmented insulin pump therapy and automated insulin suspension versus standard pump therapy for hypoglycemic unaware patients with type 1 diabetes.

PubMed

Ly, Trang T; Brnabic, Alan J M; Eggleston, Andrew; Kolivos, Athena; McBride, Margaret E; Schrover, Rudolf; Jones, Timothy W

2014-07-01

To assess the cost-effectiveness of sensor-augmented insulin pump therapy with "Low Glucose Suspend" (LGS) functionality versus standard pump therapy with self-monitoring of blood glucose in patients with type 1 diabetes who have impaired awareness of hypoglycemia. A clinical trial-based economic evaluation was performed in which the net costs and effectiveness of the two treatment modalities were calculated and expressed as an incremental cost-effectiveness ratio (ICER). The clinical outcome of interest for the evaluation was the rate of severe hypoglycemia in each arm of the LGS study. Quality-of-life utility scores were calculated using the three-level EuroQol five-dimensional questionnaire. Resource use costs were estimated using public sources. After 6 months, the use of sensor-augmented insulin pump therapy with LGS significantly reduced the incidence of severe hypoglycemia compared with standard pump therapy (incident rate difference 1.85 [0.17-3.53]; P = 0.037). Based on a primary randomized study, the ICER per severe hypoglycemic event avoided was $18,257 for all patients and $14,944 for those aged 12 years and older. Including all major medical resource costs (e.g., hospital admissions), the ICERs were $17,602 and $14,289, respectively. Over the 6-month period, the cost per quality-adjusted life-year gained was $40,803 for patients aged 12 years and older. Based on the Australian experience evaluating new interventions across a broad range of therapeutic areas, sensor-augmented insulin pump therapy with LGS may be considered a cost-effective alternative to standard pump therapy with self-monitoring of blood glucose in hypoglycemia unaware patients with type 1 diabetes. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Continuous subcutaneous insulin infusion: Special needs for children.

PubMed

Adolfsson, Peter; Ziegler, Ralph; Hanas, Ragnar

2017-06-01

Continuous subcutaneous insulin infusion (CSII) is a very common therapy for children with type 1 diabetes. Due to physiological differences they have other requirements for their insulin pump than adults. The main difference is the need for very low basal rates. Even though most available insulin pumps reach a high accuracy at usual basal rates, accuracy decreases for lower rates. In addition, the lowest delivered amount at 1 time is limiting the fine tuning of the basal rate as well as the option for temporary basal rates. Alarms in case of occlusions depend on accumulation of a certain amount of insulin in the catheter, and therefore the time until such an alarm is triggered is much longer with lower basal rates. Accordingly, the risk for hyperglycemia developing into diabetic ketoacidosis increases. The availability of bolus advisors facilitates the calculation of meal and correction boluses for children and their parents. However, there are some differences between the calculators, and the settings that the calculation is based on are very important. Better connectivity, for example with a system for continuous glucose monitoring, might help to further increase safety in the use of CSII in children. When selecting an insulin pump for a child, the features and characteristics of available pumps should be properly compared to ensure an effective and safe therapy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Boon for the Diabetic

NASA Technical Reports Server (NTRS)

1987-01-01

Diabetics are no longer concerned with scheduling activities around peaking insulin levels since the use of an external pump from Pacesetter Systems, Inc. used to deliver insulin continuously at a preprogrammed individually adjusted rate. The pump wearer can lead a more normal existence, even participate in sports or travel, and there is an even greater benefit. Research indicates that infusion of "short acting" insulin in tiny amounts over a long period - instead of "long- acting" insulin has helped many diabetics achieve better control of blood sugar levels, thereby minimizing the possibility of complications and, in some cases, even halting the progression of complications.

Implantation of programmable infusion pumps for insulin delivery in type I diabetic patients.

PubMed

Walter, H; Günther, A; Kronski, D; Flaschenträger, T; Mehnert, H

1989-06-01

Five type I diabetic patients were followed prospectively during treatment with continuous subcutaneous insulin infusion by externally worn pumps and during the first 12 months after implantation of a remote-controlled insulin infusion device (ID1, Siemens AG). Stabilized insulin (Hoe 21 GH, Hoechst AG) was infused intravenously in two and intraperitoneally in three patients. Total observation time was 47.2 patient-months after implantation. Two devices had to be explanted prematurely, one because of a technical failure after 101 days, one due to a skin necrosis over the implant after 236 days. HbA1, frequency of hypoglycemia, total insulin dose, and basal rate infusion did not change after implantation. There was a reduction in the insulin antibodies 6 months after start of intravenous or intraperitoneal insulin delivery. Fasting plasma free insulin levels could be normalized only by intraperitoneal insulin infusion. Although a technical and a surgical problem was observed, our data show the successful implantation and clinical use of programmable dosing devices and stabilized insulin.

Physical activity and sedentary behavior levels in children and adolescents with type 1 diabetes using insulin pump or injection therapy - The importance of parental activity profile.

PubMed

Michaud, Isabelle; Henderson, Mélanie; Legault, Laurent; Mathieu, Marie-Eve

2017-02-01

In children and adolescents, treatments for type 1 diabetes (T1D) have recently evolved with the introduction of the insulin pump. However, little is known about how a pump is associated with physical activity (PA) patterns. The goal of the study was to examine the activity profile of Canadian children and adolescents with T1D according to their insulin treatment (pump vs. injections), as well as barriers to exercise and parental lifestyle habits. A self-administered questionnaire was completed by 188 subjects with T1D aged 6 to 17 and their parents at the endocrinology clinic of Sainte-Justine's University Hospital Center (Montreal, Canada). Sixty percent of patients used an insulin pump. There were no significant differences in any components of the PA profile, sedentary habits, and exercise barriers between subjects using injections and those using a pump. Fear of hypoglycemia was the main PA barrier in both treatment groups. A more diverse PA practice by parents was associated with more moderate-to-vigorous PA and less screen time in adolescents. In conclusion, type of treatment was not associated with more activity in pediatric patients with T1D and a varied parental PA profile was the main factor of interest for healthier habits in adolescents with T1D. Copyright © 2017 Elsevier Inc. All rights reserved.

Toddlers' choice: Yo-Yoing diabetes control or deci-unit insulin dosing?

PubMed

Abul-Ainine, Sarah Aa; Abul-Ainine, Ahmad Aa

2012-02-15

While the incidence of toddlers' diabetes is soaring, their mainstay insulins were withdrawn, namely the weak 10% or 20% insulin mixtures (WIM), which were injected only once or twice daily. Consequently, toddlers are coerced to use an insulin pump, multi-dose insulin regime (MuDIR), mix or dilute insulins. This paper highlights the difficulties and proposes a simple solution. While an insulin pump is the best available option, it is not readily available for everyone. Mixing insulins is not sufficiently precise in small doses. Although diluting insulin would allow precise dosing and reduce the dose variability secondary to dribbling after injections, it, like insulin mixing, deprives children from using the pen and related child-friendly accessories. In MuDIR, we inject 4-5 small doses of insulin instead of 1-2 daily larger doses of WIM. Thus, on using a half unit (½unit) insulin pen, a dose of 0.5, 1, 1.5 and 2 units are adjusted in steps of 100%, 50%, 33% or 25%; unlike the advisable 5%-20%. This does not easily match the tiny erratic meals of grazing toddlers. Maternal anxiety peaks on watching yo-yoing glycemia. Carers have to accept either persistently high sugar or wild fluctuation. The risks of such poor glycemic pattern are increasingly recognized. Using insulin U20 in a ½unit disposable pen allows deci-unit dosing, with 5%-20% dose-tuning, greater accuracy on delivering small doses and reduction of dose variability from dribbling. Deci-unit dosing may help avoid wide glycemic swings and provide the affordable alternative to insulin pumps for toddlers. Deci-unit pen materializes the Human Rights of Children, a safer and effective treatment.

[Ultrasonographic evaluation of selected parameters of the endothelial function in brachial arteries and IMT measurements in carotid arteries in children with diabetes type 1 using personal insulin pumps--preliminary report].

PubMed

Tołwińska, Joanna; Głowińska-Olszewska, Barbara; Urban, Mirosława; Florys, Bozena; Peczyńska, Jadwiga

2006-01-01

Type 1 diabetes is a known risk factor for arterial atherosclerosis. The first symptoms can be found even in childhood. The ultrasonographic measurements of intimal plus medial thickness in carotid arteries (IMT) and flow mediated dilatation (FMD) evaluated in brachial arteries, play a known role in the detection in these cases. The diabetes treatment intensification is an important factor in delaying early atherosclerotic changes. Currently, intensive treatment of children's diabetes with use of continuous subcutaneous insulin infusion with personal insulin pumps is gaining more and more popularity. THE AIM OF THIS STUDY was the evaluation of IMT and FMD indexes in children suffering from type 1 diabetes in the context of treatment intensification (multidose insulin injections v. personal insulin pumps). We examined 64 children (29 boys and 35 girls) in the mean age 15.5 years treated with the multidose insulin injections method and 10 children using personal insulin pumps (4 girls and 6 boys) in the mean age 14.5 years. Using high resolution ultrasonography we evaluated IMT values in carotid arteries and FMD parameters in brachial arteries. In our analysis we estimated the blood concentration of lipid parameters, values of systolic and diastolic blood pressure, the age of diabetes onset, duration time of the illness and the values of HbA1c as a marker of metabolic control. We noticed significantly higher FMD values in patients treated with personal insulin pumps (13.7 vs. 5.5%, p=0.001). IMT values were similar in both groups (0.52 vs. 0.5 mm, p=0. 41). The level of HDL cholesterol was higher and triglycerides lower in the group with treatment intensification. The metabolic control was the same in both groups. In patients treated by the multidose insulin injections IMT correlated with systolic blood pressure values. We didn't notice any correlation between IMT and FMD in any group. 1. Treatment intensification (personal insulin pumps) influences better vascular endothelial function in type 1 diabetic children and seems to be a significant tool in delaying the atherosclerotic process. 2. We need more examinations to explain the role of treatment intensification in common carotid arteries wall morphology in type 1 diabetic children. 3. The ultrasonographic detection of atherosclerotic changes in arterial vessels can help in the evaluation of the changes due to different methods of diabetes treatment.

Insulin Pumps: What Every School Nurse Needs to Know

ERIC Educational Resources Information Center

Bierschbach, Judy Laver; Cooper, Leslie; Liedl, Jennifer A.

2004-01-01

The results of the Diabetes Control and Complications Trial revolutionized the care of people with Type 1 diabetes mellitus (DM). The era of "tight control" of blood sugars to decrease microvascular complications dawned. The subsequent technological development of insulin pumps has made it possible for individuals with Type 1 DM, as well as those…

The U.K. service level audit of insulin pump therapy in adults.

PubMed

White, H D; Goenka, N; Furlong, N J; Saunders, S; Morrison, G; Langridge, P; Paul, P; Ghatak, A; Weston, P J

2014-04-01

The National Institute for Health and Clinical Excellence (NICE) published guidelines for the use of continuous subcutaneous insulin infusion in 2008 (technology appraisal 151). The first U.K.-wide insulin pump audit took place in 2012 with the aim of determining adherence to the guidance issued in NICE technology appraisal 151. The results of the adult service level audit are reported here. All centres providing continuous subcutaneous insulin infusion services to adults with diabetes in the U.K. were invited to participate. Audit metrics were aligned to technology appraisal 151. Data entry took place online using a DiabetesE formatted data collection tool. One hundred and eighty-three centres were identified as delivering adult continuous subcutaneous insulin infusion services in the U.K., of which 178 (97.3%) participated in the audit. At the time of the audit, 13 428 adults were using insulin pump therapy, giving an estimated prevalence of use of 6%. Ninety-three per cent of centres did not report any barriers in obtaining funding for patients who fulfilled NICE criteria. The mean number of consultant programmed activities dedicated to continuous subcutaneous insulin infusion services was 0.96 (range 0-8), mean whole-time equivalent diabetes specialist nurses was 0.62 (range 0-3) and mean whole-time equivalent dietitian services was 0.3 (range 0-2), of which 39, 61 and 60%, respectively, were not formally funded. The prevalence of continuous subcutaneous insulin infusion use in the U.K. falls well below the expectation of NICE (15-20%) and that of other European countries (> 15%) and the U.S.A. (40%). This may be attributable, in part, to lack of healthcare professional time needed for identification and training of new pump therapy users. © 2013 The Authors. Diabetic Medicine © 2013 Diabetes UK.

[From insulin pump and continuous glucose monitoring to the artificial pancreas].

PubMed

Apablaza, Pamela; Soto, Néstor; Codner, Ethel

2017-05-01

Technology for diabetes care has undergone major development during recent decades. These technological advances include continuous subcutaneous insulin infusion (CSII), also known as insulin pumps, and real-time continuous glucose monitoring system (RT-CGMS). The integration of CSII and RT-CGMS into a single device has led to sensor-augmented pump therapy and more recently, a technology that has automated delivery of basal insulin therapy, known as hybrid system. These new technologies have led to benefits in attaining better metabolic control and decreasing the incidence of severe hypoglycemia, especially in patients with type 1 diabetes. This review describes the types of technologies currently available or under investigation for these purposes, their benefits and disadvantages, recommendations and the appropriate patient selection for their use. The clinical use of the hybrid system and artificial pancreas seem to be possible in the near future.

Analysis of insulin pump settings in children and adolescents with type 1 diabetes mellitus.

PubMed

Lau, Yu Ning; Korula, Sophy; Chan, Albert K; Heels, Kristine; Krass, Ines; Ambler, Geoffrey

2016-08-01

To characterize current insulin pump settings used in young patients with type 1 diabetes mellitus (T1DM) and to assess their relationship to glycemic control. This retrospective study included patients aged <18 yr old with T1DM >1 yr using a Medtronic pump device. Pump data including number of blood glucose (BG) tests per day, basal and bolus insulin parameters, carbohydrate ratio (CR), and insulin sensitivity factors (ISFs) were averaged over 14 d for statistical analyses. Anthropometric data and recent glycosylated hemoglobin A1c (HbA1c) were recorded. A total of 292 patients (144 males and 148 females) were included in the study. Participants had a median age (interquartile range, IQR) of 12.9 yr (10.0-15.1 yr) and pump duration of 2.8 yr (1.5-4.2 yr). No significant differences in median HbA1c (IQR) were observed in preschool [n = 14; HbA1c 7.8% (7.3-8.3%)], prepubertal [n = 105; HbA1c 8.1% (7.7-8.9%)], and adolescent subjects [n = 173; HbA1c 8.4% (7.7-9.0%)]. Adolescents took significantly fewer boluses and BG tests per day compared with younger children (p < 0.05). Age-specific diurnal variation in basal insulin delivery was noted. Additionally, stronger carbohydrate cover and weaker corrections were used in real-life compared with theoretical 500 and 100 rules, respectively. Lower HbA1c was associated with higher number of daily boluses, greater number of BG tests per day, lower average CR/500 rule ratio, and higher average ISF/100 rule ratio adjusted for age (R(2) = 0.22; p < 0.01). Insulin pump therapy requires continuous adjustments and glycemic targets are achieved by a minority. We believe this is the first study in pediatric cohort looking at association between CR and ISF with glycemic control. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Formal verification of medical monitoring software using Z language: a representative sample.

PubMed

Babamir, Seyed Morteza; Borhani, Mehdi

2012-08-01

Medical monitoring systems are useful aids assisting physicians in keeping patients under constant surveillance; however, taking sound decision by the systems is a physician concern. As a result, verification of the systems behavior in monitoring patients is a matter of significant. The patient monitoring is undertaken by software in modern medical systems; so, software verification of modern medial systems have been noticed. Such verification can be achieved by the Formal Languages having mathematical foundations. Among others, the Z language is a suitable formal language has been used to formal verification of systems. This study aims to present a constructive method to verify a representative sample of a medical system by which the system is visually specified and formally verified against patient constraints stated in Z Language. Exploiting our past experience in formal modeling Continuous Infusion Insulin Pump (CIIP), we think of the CIIP system as a representative sample of medical systems in proposing our present study. The system is responsible for monitoring diabetic's blood sugar.

Who gains clinical benefit from using insulin pump therapy? A qualitative study of the perceptions and views of health professionals involved in the Relative Effectiveness of Pumps over MDI and Structured Education (REPOSE) trial.

PubMed

Lawton, J; Kirkham, J; Rankin, D; White, D A; Elliott, J; Jaap, A; Smithson, W H; Heller, S

2016-02-01

To explore health professionals' views about insulin pump therapy [continuous subcutaneous insulin infusion (CSII)] and the types of individuals they thought would gain greatest clinical benefit from using this treatment. In-depth interviews with staff (n = 18) who delivered the Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE) trial. Data were analysed thematically. Staff perceived insulin pumps as offering a better self-management tool to some individuals due to the drip feed of insulin, the ability to alter basal rates and other advanced features. However, staff also noted that, because of the diversity of features on offer, CSII is a more technically complex therapy to execute than multiple daily injections. For this reason, staff described how, alongside clinical criteria, they had tended to select individuals for CSII in routine clinical practice based on their perceptions about whether they possessed the personal and psychological attributes needed to make optimal use of pump technology. Staff also described how their assumptions about personal and psychological suitability had been challenged by working on the REPOSE trial and observing individuals make effective use of CSII who they would not have recommended for this type of therapy in routine clinical practice. Our findings add to those studies that highlight the difficulties of using patient characteristics and variables to predict clinical success using CSII. To promote equitable access to CSII, attitudinal barriers and prejudicial assumptions amongst staff about who is able to make effective use of CSII may need to be addressed. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

Insulin pump-associated adverse events in children and adolescents--a prospective study.

PubMed

Wheeler, Benjamin J; Heels, Kristine; Donaghue, Kim C; Reith, David M; Ambler, Geoffrey R

2014-09-01

Intensive insulin regimens are now the mainstay of modern, type 1 diabetes mellitus management. Insulin pumps (CSII) are a key technique used. Although there has been considerable study of outcomes, there are few recent data on CSII-associated adverse events (AEs) and their incidence and characteristics. Phone calls to our 24-h diabetes support service were screened for CSII-associated AEs. Phone interviews were conducted with the parent/patient, within 96 h of the event. Interviews explored AE characteristics and the role of the user, as well as questions relating to outcome and the impact to the family and patient. Comparisons were made with clinic CSII patients not reporting an AE. Over a 16-week study period, 50 confirmed AEs occurred in 45 of 405 (11.1%) patients. This was annualized to an AE incidence of 40 AEs/100 person-years. Pump malfunction and infusion set/site failures were the most common events reported, occurring in 27 (54.0%) and 18 (36.0%) AEs, respectively. A user- or education-related issue was implicated in 22 (44.0%) events. Pump replacement occurred in 19 of 50 occurrences (38.0%). Additionally, 16 (32.0%) reported a hospital admission or emergency department attendance as a consequence. When compared with those on CSII not reporting an AE, AEs were associated with age <10 years (odds ratio=3.2 [95% confidence interval, 1.7-6.1]) but not with gender, glycosylated hemoglobin, diabetes duration, or pumping duration. This is the first prospective study to look at AEs in modern-generation insulin pumps. AEs appear common and should be anticipated. Their origin is multifactorial, with the pump, associated consumables, and the user all being important factors. Ongoing support and anticipatory education are essential to minimize pump-associated AEs and their impact.

Absorption of subcutaneously infused insulin: influence of the basal rate pulse interval.

PubMed

Hildebrandt, P; Birch, K; Jensen, B M; Kühl, C; Brange, J

1985-01-01

Eight insulin-dependent diabetic patients were given two constant infusions (each 1 IU/h) of 125I-labeled insulin into the abdominal subcutaneous tissue for about 12 h. Insulin was infused in pulses into one side of the abdomen in 6-min intervals (by means of an Auto-Syringe pump) and in the other side of the abdomen, insulin was infused in 1-h intervals (by means of a Medix pump). The size of the subcutaneous depots was continuously measured by counting the radioactivity at the infusion sites. After starting the infusions, the two depots were built up to steady-state levels at the same time and of the same size (approximately 3 IU) and with similar absorption rates. Thus, during basal rate insulin infusion, identical insulin absorption kinetics was achieved, irrespective of a 10-fold difference in the pulse rate.

Sustained efficacy of insulin pump therapy compared with multiple daily injections in type 2 diabetes: 12-month data from the OpT2mise randomized trial.

PubMed

Aronson, R; Reznik, Y; Conget, I; Castañeda, J A; Runzis, S; Lee, S W; Cohen, O

2016-05-01

To compare insulin pump therapy and multiple daily injections (MDI) in patients with type 2 diabetes receiving basal and prandial insulin analogues. After a 2-month dose-optimization period, 331 patients with glycated haemoglobin (HbA1c) levels ≥8.0% and ≤12% were randomized to pump therapy or continued MDI for 6 months [randomization phase (RP)]. The MDI group was subsequently switched to pump therapy during a 6-month continuation phase (CP). The primary endpoint was the between-group difference in change in mean HbA1c from baseline to the end of the RP. The mean HbA1c at baseline was 9% in both groups. At the end of the RP, the reduction in HbA1c was significantly greater with pump therapy than with MDI (-1.1 ± 1.2% vs -0.4 ± 1.1%; p < 0.001). The pump therapy group maintained this improvement to 12 months while the MDI group, which was switched to pump therapy, showed a 0.8% reduction: the final HbA1c level was identical in both arms. In the RP, total daily insulin dose (TDD) was 20.4% lower with pump therapy than with MDI and remained stable in the CP. The MDI-pump group showed a 19% decline in TDD, such that by 12 months TDD was equivalent in both groups. There were no differences in weight gain or ketoacidosis between groups. In the CP, one patient in each group experienced severe hypoglycaemia. Pump therapy has a sustained durable effect on glycaemic control in uncontrolled type 2 diabetes. © 2016 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.

Comparative study on treatment satisfaction and health perception in children and adolescents with type 1 diabetes mellitus on multiple daily injection of insulin, insulin pump and sensor-augmented pump therapy.

PubMed

Hussain, Tara; Akle, Mariette; Nagelkerke, Nico; Deeb, Asma

2017-01-01

Diabetes management imposes considerable demands on patients. Treatment method used has an impact on treatment satisfaction. We aim to examine the relationship between treatment satisfaction and health perception with the method used for treatment of type 1 diabetes mellitus in children and adolescents. We have interviewed patients with type 1 diabetes mellitus using questionnaires to assess treatment satisfaction and health perception. Patients were divided into three groups based on treatment used: multiple daily injection, insulin pump and sensor-augmented pump therapy. Comparison of scores was done between the groups. A total of 72 patients were enrolled (36 males). Mean age (standard deviation) was 11.4 (4.4) years and duration of diabetes of 4.9 (3.5) years. Mean (standard deviation) HbA1c was 8.1 (1.2). Median (range) duration of sensor use was 17.7 (3-30) days/month. Mean scale for treatment satisfaction and health perception questions was 25.3, 29.7 and 31.7 and 60, 79.7 and 81 for the multiple daily injection, pump and sensor-augmented pump, respectively (p = 0.00). Significant difference was seen between the multiple daily injection and both other groups. Sensor-augmented pump group scored higher than the pump group. However, the difference was not statistically significant. Duration of sensor use showed no correlation with treatment satisfaction. The method used for diabetes treatment has an impact on patients' satisfaction and health perception in children and adolescents with type 1 diabetes mellitus. Insulin pump users have a higher treatment satisfaction and better health perception than those on multiple daily injection. Augmenting pump therapy with sensor use adds value to treatment satisfaction without correlation with the duration of the sensors use.

Sustained efficacy of insulin pump therapy compared with multiple daily injections in type 2 diabetes: 12‐month data from the OpT2mise randomized trial

PubMed Central

Reznik, Y.; Conget, I.; Castañeda, J. A.; Runzis, S.; Lee, S. W.; Cohen, O.

2016-01-01

Aims To compare insulin pump therapy and multiple daily injections (MDI) in patients with type 2 diabetes receiving basal and prandial insulin analogues. Methods After a 2‐month dose‐optimization period, 331 patients with glycated haemoglobin (HbA1c) levels ≥8.0% and ≤12% were randomized to pump therapy or continued MDI for 6 months [randomization phase (RP)]. The MDI group was subsequently switched to pump therapy during a 6‐month continuation phase (CP). The primary endpoint was the between‐group difference in change in mean HbA1c from baseline to the end of the RP. Results The mean HbA1c at baseline was 9% in both groups. At the end of the RP, the reduction in HbA1c was significantly greater with pump therapy than with MDI (−1.1 ± 1.2% vs −0.4 ± 1.1%; p < 0.001). The pump therapy group maintained this improvement to 12 months while the MDI group, which was switched to pump therapy, showed a 0.8% reduction: the final HbA1c level was identical in both arms. In the RP, total daily insulin dose (TDD) was 20.4% lower with pump therapy than with MDI and remained stable in the CP. The MDI–pump group showed a 19% decline in TDD, such that by 12 months TDD was equivalent in both groups. There were no differences in weight gain or ketoacidosis between groups. In the CP, one patient in each group experienced severe hypoglycaemia. Conclusions Pump therapy has a sustained durable effect on glycaemic control in uncontrolled type 2 diabetes. PMID:26854123

Validation of Algorithms for Basal Insulin Rate Reductions in Type 1 Diabetic Patients Practising Physical Activity

ClinicalTrials.gov

2013-04-19

Type 1 Diabetes With a Subcutaneous Insulin Pump; Adjustment of the Recommended Basal Insulin Flow Rate in the Event of Physical Activity; Adjustment of the Recommended Prandial Insulin in the Event of Physical Activity

Medicines for Diabetes

MedlinePlus

... will help a kid stay healthy and feel good. What Is Insulin? The most common diabetes medicine is insulin, which you can get through shots or an insulin pump . Insulin is a hormone that helps ... also might be a good idea for older brothers and sisters, babysitters, teachers, ...

An intensive insulinotherapy mobile phone application built on artificial intelligence techniques.

PubMed

Curran, Kevin; Nichols, Eric; Xie, Ermai; Harper, Roy

2010-01-01

Software to help control diabetes is currently an embryonic market with the main activity to date focused mainly on the development of noncomputerized solutions, such as cardboard calculators or computerized solutions that use "flat" computer models, which are applied to each person without taking into account their individual lifestyles. The development of true, mobile device-driven health applications has been hindered by the lack of tools available in the past and the sheer lack of mobile devices on the market. This has now changed, however, with the availability of pocket personal computer handsets. This article describes a solution in the form of an intelligent neural network running on mobile devices, allowing people with diabetes access to it regardless of their location. Utilizing an easy to learn and use multipanel user interface, people with diabetes can run the software in real time via an easy to use graphical user interface. The neural network consists of four neurons. The first is glucose. If the user's current glucose level is within the target range, the glucose weight is then multiplied by zero. If the glucose level is high, then there will be a positive value multiplied to the weight, resulting in a positive amount of insulin to be injected. If the user's glucose level is low, then the weights will be multiplied by a negative value, resulting in a decrease in the overall insulin dose. A minifeasibility trial was carried out at a local hospital under a consultant endocrinologist in Belfast. The short study ran for 2 weeks with six patients. The main objectives were to investigate the user interface, test the remote sending of data over a 3G network to a centralized server at the university, and record patient data for further proofing of the neural network. We also received useful feedback regarding the user interface and the feasibility of handing real-world patients a new mobile phone. Results of this short trial confirmed to a large degree that our approach (which also can be known as intensive insulinotherapy) has value and perhaps that our neural network approach has implications for future intelligent insulin pumps. Currently, there is no software available to tell people with diabetes how much insulin to inject in accordance with their lifestyle and individual inputs, which leads to adjustments in software predictions on the amount of insulin to inject. We have taken initial steps to supplement the knowledge and skills of health care professionals in controlling insulin levels on a daily basis using a mobile device for people who are less able to manage their disease, especially children and young adults. 2010 Diabetes Technology Society.

An Intensive Insulinotherapy Mobile Phone Application Built on Artificial Intelligence Techniques

PubMed Central

Curran, Kevin; Nichols, Eric; Xie, Ermai; Harper, Roy

2010-01-01

Background Software to help control diabetes is currently an embryonic market with the main activity to date focused mainly on the development of noncomputerized solutions, such as cardboard calculators or computerized solutions that use “flat” computer models, which are applied to each person without taking into account their individual lifestyles. The development of true, mobile device-driven health applications has been hindered by the lack of tools available in the past and the sheer lack of mobile devices on the market. This has now changed, however, with the availability of pocket personal computer handsets. Method This article describes a solution in the form of an intelligent neural network running on mobile devices, allowing people with diabetes access to it regardless of their location. Utilizing an easy to learn and use multipanel user interface, people with diabetes can run the software in real time via an easy to use graphical user interface. The neural network consists of four neurons. The first is glucose. If the user's current glucose level is within the target range, the glucose weight is then multiplied by zero. If the glucose level is high, then there will be a positive value multiplied to the weight, resulting in a positive amount of insulin to be injected. If the user's glucose level is low, then the weights will be multiplied by a negative value, resulting in a decrease in the overall insulin dose. Results A minifeasibility trial was carried out at a local hospital under a consultant endocrinologist in Belfast. The short study ran for 2 weeks with six patients. The main objectives were to investigate the user interface, test the remote sending of data over a 3G network to a centralized server at the university, and record patient data for further proofing of the neural network. We also received useful feedback regarding the user interface and the feasibility of handing real-world patients a new mobile phone. Results of this short trial confirmed to a large degree that our approach (which also can be known as intensive insulinotherapy) has value and perhaps that our neural network approach has implications for future intelligent insulin pumps. Conclusions Currently, there is no software available to tell people with diabetes how much insulin to inject in accordance with their lifestyle and individual inputs, which leads to adjustments in software predictions on the amount of insulin to inject. We have taken initial steps to supplement the knowledge and skills of health care professionals in controlling insulin levels on a daily basis using a mobile device for people who are less able to manage their disease, especially children and young adults. PMID:20167186

Paediatric type 1 diabetes in Ireland--results of the first national audit.

PubMed

Hawkes, C P; Murphy, N P

2014-04-01

The aim of this study was to describe the services provided for children with type 1 diabetes in the Republic of Ireland, and to identify a baseline from which services and outcomes might be improved. Lead clinicians in 17 of the 19 centres providing paediatric type 1 diabetes care responded to requests for information from 2012 regarding demographics, patient numbers, diagnostics, outpatient management, multidisciplinary team resources, comorbidity screening, transition policy, clinical guidelines, and use of insulin pumps. The total number of patients attending these centres was 2518. Eight centres initiate insulin pump therapy. Insulin pump usage ranged from 0 to 42% of patients attending each centre. Self reported clinic mean haemoglobin A1c ranged from 8.2 to 9.4% (66.1 to 79.2 mmol/mol). Variation existed in guideline availability, frequency of clinic appointments, age of transition and insulin types used. We recommend a national approach to standardising and improving care for these patients.

Insulin oedema and treatment-induced neuropathy occurring in a 20-year-old patient with Type 1 diabetes commenced on an insulin pump.

PubMed

Rothacker, K M; Kaye, J

2014-01-01

Oedema may occur following initiation or intensification of insulin therapy in patients with Type 1 and Type 2 diabetes. Mild oedema is thought to be not uncommon, but under-reported, whilst generalized oedema with involvement of serous cavities has rarely been described. Multiple pathogenic mechanisms have been proposed, including insulin-induced sodium and water retention. Patients at greater risk for insulin oedema include those with poor glycaemic control. Dramatic improvement in glycaemic control is also associated with sensory and autonomic neuropathy. We describe a case of generalized oedema occurring in a 20-year-old, low body weight patient with Type 1 diabetes with poor glycaemic control 3 days following commencement of an insulin pump; blood sugars had dramatically improved with this treatment. Alternative causes for oedema were excluded. Oedema slowly improved with insulin dose reduction with higher blood sugar targets plus frusemide treatment. Subsequent to oedema resolution, the patient unfortunately developed generalized neuropathic pain, thought to be another manifestation of rapid improvement in glycaemic control. Caution should be taken when a patient with diabetes that is poorly controlled has an escalation in therapy that may dramatically improve their blood sugar levels; this includes the initiation of an insulin pump. Clinicians and patients should be aware of the potential risk of insulin oedema, treatment-induced neuropathy and worsening of diabetic retinopathy in the setting of rapid improvement in glycaemic control. © 2013 The Authors. Diabetic Medicine © 2013 Diabetes UK.

Analysis of the Environmental Impact of Insulin Infusion Sets Based on Loss of Resources with Waste

PubMed Central

Pfützner, Andreas; Musholt, Petra B; Malmgren-Hansen, Bjoern; Nilsson, Nils H; Forst, Thomas

2011-01-01

Insulin pump therapy [continuous subcutaneous insulin infusion (CSII)] requires regular change of infusion sets every 2-3 days in order to minimize the risk of skin irritations or other adverse events. This has been discussed to be a potential burden to the environment. The purpose of this analysis was to perform an environmental assessment of insulin pump infusion sets based on loss of resources occurring during incineration of the discarded products and by means of a lifecycle concept used to weight a material in relation to its rareness on earth and its consumption. In addition to five infusion sets (Inset30, InsetII, Comfort, Quick-set, and Cleo), a patch pump (Omnipod) was also included in this analysis. The annual loss in waste of the so called “person reserve” of 3 days of catheter use was compared with daily consumption of a cup of coffee in a disposable paper cup and to a soft drink in an aluminum can. The weight-based loss in resources through waste for the infusion sets (except for Cleo) corresponded to 70-200% of the loss of resources for a coffee cup (Cleo, 320%; Omnipod, 1,821,600%) and to 1-3% of the loss from an aluminum soft drink can (Cleo, 5%; Omnipod, 31,200%). The loss or resources by use of infusion sets used in insulin pump therapy appears to be low and is similar to the burden induced by the uptake of one cup of coffee per day. The loss or resources with regular CSII is considerably lower than the loss or resources induced by patch pumps. PMID:21880223

Hypoglycemia Prevention and User Acceptance of an Insulin Pump System with Predictive Low Glucose Management.

PubMed

Choudhary, Pratik; Olsen, Birthe S; Conget, Ignacio; Welsh, John B; Vorrink, Linda; Shin, John J

2016-05-01

The MiniMed 640G sensor-augmented insulin pump system (Medtronic, Inc., Northridge, CA) can automatically suspend insulin delivery in advance of predicted hypoglycemia and restart it upon recovery. The aims of this analysis were to determine the rate at which predicted hypoglycemia was avoided with this strategy, as well as to assess user acceptance of the system and its insulin management features. Forty subjects with type 1 diabetes used the system for 4 weeks. We retrospectively evaluated performance of the system, using downloaded pump and sensor data, and evaluated user acceptance via questionnaires. There were 2,322 suspend before low events (2.1 per subject-day). The mean (± SD) duration of pump suspension events was 56.4 ± 9.6 min, and the mean subsequent sensor glucose (SG) nadir was 71.8 ± 5.2 mg/dL. SG values following 1,930 (83.1%) of the predictive suspensions did not reach the preset low limit. Nadir SG values of ≤50 and ≤60 mg/dL were seen in 207 (8.9%) and 356 (15.3%) of the predictive suspensions, respectively. Blood glucose (BG) and SG values before and during the study were comparable (P > 0.05). The mean absolute relative difference between paired SG and BG values was 10.9 ± 13.8%. Subjects felt confident using the system, agreed that it helped protect them from hypoglycemia, and wished to continue using it. Automatic insulin pump suspension as implemented in the MiniMed 640G system can help patients avoid hypoglycemia, without significantly increasing hyperglycemia.

Diabetes Mellitus and the Insulin Pump: What Teachers Need to Know

ERIC Educational Resources Information Center

Obringer, S. John; Coffey, Kenneth

2006-01-01

Diabetes is a condition where high amounts of glucose are found in the bloodstream due to impaired secretion of insulin. The hormone insulin was discovered by two physicians, Fredrick Banting and James Mcleod in 1921. Individuals with severe diabetes typically controlled their glucose level with multiple daily injections of insulin. Recently the…

A Randomized Controlled Study of an Insulin Dosing Application That Uses Recognition and Meal Bolus Estimations

PubMed Central

Pańkowska, Ewa; Ładyżyński, Piotr; Foltyński, Piotr; Mazurczak, Karolina

2016-01-01

Background: Throughout the insulin pump therapy, decisions of prandial boluses programming are taken by patients individually a few times every day, and, moreover, this complex process requires numerical skills and knowledge in nutrition components estimation. The aim of the study was to determine the impact of the expert system, supporting the patient’s decision on meal bolus programming, on the time in range of diurnal glucose excursion in patients treated with continuous subcutaneous insulin infusion (CSII). Methods: The crossover, randomized study included 12 adults, aged 19 to 53, with type 1 diabetes mellitus, duration ranging from 7 to 30 years. Patients were educated in complex food counting, including carbohydrate units (CU) and fat-protein units (FPU). Subsequently, they were randomly allocated to the experimental group (A), which used the expert software named VoiceDiab, and the control group (B), using a manual method of meal-bolus estimation. Results: It was found that 66.7% of patients within the A group statistically reported a relevant increase in the percentage (%) of sensor glucose (SG) in range (TIR 70-180 mg/dl), compared to the B group. TIR (median) reached 53.9% in the experimental group (A) versus 44% within the control group (B), P < .05. The average difference in the number of hypoglycemia episodes was not statistically significant (–0.2%, SD 11.6%, P = .93). The daily insulin requirement in both groups was comparable—the average difference in total daily insulin dose between two groups was 0.26 (SD 7.06 IU, P = .9). Conclusion: The expert system in meal insulin dosing allows improvement in glucose control without increasing the rates of hypoglycemia or the insulin requirement. PMID:28264177

Depressive Symptoms, Emotion Dysregulation, and Bulimic Symptoms in Youth With Type 1 Diabetes: Varying Interactions at Diagnosis and During Transition to Insulin Pump Therapy.

PubMed

Young-Hyman, Deborah L; Peterson, Claire M; Fischer, Sarah; Markowitz, Jessica T; Muir, Andrew B; Laffel, Lori M

2016-07-01

This study evaluated the associations between depressive symptoms, emotion dysregulation and bulimic symptoms in youth with type 1 diabetes (T1D) in the context of the diagnosis and treatment of T1D. Study participants were 103 youth in 2 distinct groups: newly diagnosed (New) or transitioning to pump therapy (continuous subcutaneous insulin infusion [CSII]; "Pump"), who completed questionnaires regarding symptoms of depression, emotion dysregulation, and bulimia. Glycemic control (A1c), height, weight, and questionnaires were evaluated within 10 days of diagnosis (n = 58) or at education/clinic visit before starting insulin utilizing CSII (n = 45). In the newly diagnosed group, only depression accounted for significant variance in bulimia scores (β = .47, P < .01). For the group with disease treatment experience (Pump), but not for the newly diagnosed group (New), greater depressive symptoms and emotion dysregulation were associated with greater bulimic symptoms. Depressive symptoms and emotion dysregulation, an indicator of poor coping/behavioral control, could help explain adoption of disordered eating behaviors in youth with T1D who are transitioning to pump therapy. © 2016 Diabetes Technology Society.

Insulin compatibility with polymer materials used in external pump infusion systems.

PubMed

Melberg, S G; Havelund, S; Villumsen, J; Brange, J

1988-04-01

In a study designed to mimic actual user conditions for external insulin pump infusion, the insulin quality after passage through the infusion set was assessed by various analytical methods, including high performance liquid chromatography. The two infusion sets tested consisted of, firstly, a polyvinylchloride/rubber syringe and a polyvinylchloride catheter sterilized by gamma irradiation and, secondly, a polyethylene/polypropylene syringe connected to a polyethylene catheter and sterilized by ethylene oxide. The insulin solution delivered through the PVC infusion set showed a reduction of preservative to less than 30% of the initial content and increased formation of chemical transformation products of insulin varying from twice the reference level during the first day to more than three times on the third day. By contrast, the polyethylene/polypropylene infusion system showed only a minor decrease in preservative content and no increase in chemical transformation. These effects were observed irrespective of the brand of insulin and were not affected by increase of the zinc content of the insulin solution. Investigation of the influence of the sterilization methods performed on polyvinylchloride and polyethylene catheters revealed that gamma irradiated polyvinylchloride catheters were markedly harmful to the insulin solution, whereas ethylene oxide sterilization did not influence the chemical stability of insulin.

Prevalence of Insulin Pump Therapy and Its Association with Measures of Glycemic Control: Results from the Canadian Study of Longevity in Type 1 Diabetes.

PubMed

Boulet, Geneviève; Halpern, Elise M; Lovblom, Leif E; Weisman, Alanna; Bai, Johnny-Wei; Eldelekli, Devrim; Keenan, Hillary A; Brent, Michael H; Paul, Narinder; Bril, Vera; Cherney, David Z I; Perkins, Bruce A

2016-05-01

We aimed to determine cross-sectional insulin pump prevalence and factors associated with measures of glycemic control as a secondary analysis in a long-standing type 1 diabetes mellitus (T1DM) national cohort. Canadian participants with ≥50 years of T1DM (n = 305) were administered a comprehensive mail-based questionnaire including acquisition of contemporaneous laboratory results. Factors associated with pump use, glycosylated hemoglobin (HbA1c), and hypoglycemia were analyzed by regression. The 305 participants had a median age of 65 [interquartile range, 59, 71] years, median diabetes duration of 54 [51, 59] years, and mean HbA1c level of 7.5 ± 1.1%. Prevalence of pump use was 44% (133/305), with median duration of use 8 [4, 13] years. Compared with the non-pump subgroup, the pump subgroup had numerically lower but similar HbA1c levels (7.4 ± 0.9% vs. 7.6 ± 1.2%; P = 0.22) and reported greater numbers of minor hypoglycemia events (6.5 vs. 5.1 events/patient·month; P = 0.004) and fewer severe hypoglycemia events (0.5 vs. 1.3 events/patient·year; P = 0.02) in the past year. More frequent daily glucose tests and more frequent minor hypoglycemia events-but not pump therapy or its prescription parameters-were independently associated with lower HbA1c level in multivariable regression. However, use of insulin pump and habitual use of continuous glucose monitoring (≥1 week/month) were each independently associated with lower risk of severe hypoglycemia (risk ratio = 0.50 [P < 0.0001] and 0.30 [P = 0.001], respectively). Insulin pump and continuous glucose monitoring technologies were associated with lower risk of severe hypoglycemia, while frequent daily glucose testing was associated with lower HbA1c level. These findings imply that basic self-management skill and technology play complementary roles in glycemic control among older adults with long-standing T1DM.

Use of insulin pump therapy in children and adolescents with type 1 diabetes and its impact on metabolic control: comparison of results from three large, transatlantic paediatric registries.

PubMed

Sherr, Jennifer L; Hermann, Julia M; Campbell, Fiona; Foster, Nicole C; Hofer, Sabine E; Allgrove, Jeremy; Maahs, David M; Kapellen, Thomas M; Holman, Naomi; Tamborlane, William V; Holl, Reinhard W; Beck, Roy W; Warner, Justin T

2016-01-01

While the use of insulin pumps in paediatrics has expanded dramatically, there is still considerable variability among countries in the use of pump technology. The present study sought to describe differences in metabolic control and pump use in young people with type 1 diabetes using data collected in three multicentre registries. Data for the years 2011 and 2012 from 54,410 children and adolescents were collected from the Prospective Diabetes Follow-up Registry (DPV; n = 26,198), T1D Exchange (T1DX; n = 13,755) and the National Paediatric Diabetes Audit (NPDA; n = 14,457). The modality of insulin delivery, based on age, sex and ethnic minority status, and the impact of pump use on HbA1c levels were compared. The overall mean HbA1c level was higher in the NPDA (8.9 ± 1.6% [74 ± 17.5 mmol/mol]) than in the DPV (8.0 ± 1.6% [64 ± 17.0 mmol/mol], p < 0.001) and T1DX (8.3 ± 1.4% [68 ± 15.4 mmol/mol], p < 0.001). Conversely, pump use was much lower in the NPDA (14%) than in the DPV (41%, p < 0.001) and T1DX (47%, p < 0.001). In a pooled analysis, pump use was associated with a lower mean HbA1c (pump: 8.0 ± 1.2% [64 ± 13.3 mmol/mol] vs injection: 8.5 ± 1.7% [69 ± 18.7 mmol/mol], p < 0.001). In all three registries, those with an ethnic minority status were less likely to be treated with a pump (p < 0.001) and boys were treated with a pump less often compared with girls (p < 0.001). Despite similar clinical characteristics and proportion of minority participants, substantial differences in metabolic control exist across the three large transatlantic registries of paediatric patients with type 1 diabetes, which appears to be due in part to the frequency of insulin pump therapy.

Adjusting insulin doses in patients with type 1 diabetes that use insulin pump and continuous glucose monitoring - Variations among countries and physicians.

PubMed

Nimri, Revital; Dassau, Eyal; Segall, Tomer; Muller, Ido; Bratina, Natasa; Kordonouri, Olga; Bello, Rachel; Biester, Torben; Dovc, Klemen; Tenenbaum, Ariel; Brener, Avivit; Šimunović, Marko; Sakka, Sophia D; Nevo Shenker, Michal; Passone, Caroline Gb; Rutigliano, Irene; Tinti, Davide; Bonura, Clara; Caiulo, Silvana; Ruszala, Anna; Piccini, Barbara; Giri, Dinesh; Stein, Ronnie; Rabbone, Ivana; Bruzzi, Patrizia; Omladič, Jasna Šuput; Steele, Caroline; Beccuti, Guglielmo; Yackobovitch-Gavan, Michal; Battelino, Tadej; Danne, Thomas; Atlas, Eran; Phillip, Moshe

2018-06-08

To evaluate physicians' adjustments of insulin pump settings based on continuous glucose monitoring (CGM) for patients with type 1 diabetes and to compare physicians' to automated insulin dose adjustments. 26 physicians from 16 centers in Europe, Israel and South-America participated in the study. All were asked to adjust insulin dosing based on insulin pump, CGM and glucometer downloads of 15 patients (mean age 16.2 ± 4.3 y, 6 females, mean A1c 8.3 ± 0.9%) gathered over a 3-week period. Recommendations were compared for the relative changes in the basal, carbohydrate-ratio (CR) and correction-factor (CF) plans among physicians, among centers and between the physicians and an automated algorithm (DreaMed Advisor Pro). Study endpoints were the percentage of comparison points for which there was full agreement on the trend of insulin dose adjustments (same trend), partial agreement (increase/decrease vs. no change) and full disagreement (opposite trend). Percentage of full agreement between physicians on the trend of insulin adjustments of the basal, CR and CF plans was 41±9%, 45±11% and 45.5±13%, and of complete disagreement was 12±7%, 9.5±7% and 10±8%, respectively. Significantly similar results were found between the physicians and the DreaMed Advisor Pro. The Advisor magnitude of insulin dose change was at least equal or less than proposed by the physicians. Physicians provide different insulin dose recommendations based on the same data sets. The automated advice of the DreaMed Advisor Pro didn't differ significantly from the advice given by the physicians in the direction or magnitude of the insulin dosing. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Optimal insulin pump dosing and postprandial glycemia following a pizza meal using the continuous glucose monitoring system.

PubMed

Jones, Susan M; Quarry, Jill L; Caldwell-McMillan, Molly; Mauger, David T; Gabbay, Robert A

2005-04-01

We attempted to identify an optimal insulin pump meal bolus by comparing postprandial sensor glucose values following three methods of insulin pump meal bolusing for a consistent pizza meal. Twenty-four patients with type 1 diabetes participated in a study to compare postprandial glucose values following three meal bolus regimens for a consistent evening pizza meal. Each participant utilized the following insulin lispro regimens on consecutive evenings, and glucose values were tracked by the Continuous Glucose Monitoring System (CGMS, Medtronic MiniMed, Northridge, CA): (a) single-wave bolus (100% of insulin given immediately); (b) 4-h dual-wave bolus (50% of insulin given immediately and 50% given over a 4-h period); and (c) 8-h dual-wave bolus (50% of insulin given immediately and 50% given over a 8-h period). Total insulin bolus amount was kept constant for each pizza meal. Divergence in blood glucose among the regimens was greatest at 8-12 h. The 8-h dual-wave bolus provided the best glycemic control and lowest mean glucose values (singlewave bolus, 133 mg/dL; 4-h dual-wave bolus, 145 mg/dL; 8-h dual-wave bolus, 104 mg/dL), leading to a difference in mean glucose of 29 mg/dL for the single-wave bolus versus the 8-h dual-wave bolus and 42 mg/dL for the 4-h dual-wave bolus versus the 8-h dual-wave bolus. The lower mean glucose in the 8-h dual-wave bolus was not associated with any increased incidence of hypoglycemia. Use of a dual-wave bolus extended over an 8-h period following a pizza meal provided significantly less postprandial hyperglycemia in the late postprandial period (8-12 h) with no increased risk of hypoglycemia.

Exponential increase in postprandial blood-glucose exposure with increasing carbohydrate loads using a linear carbohydrate-to-insulin ratio.

PubMed

Marran, K J; Davey, B; Lang, A; Segal, D G

2013-04-10

Postprandial glucose excursions contribute significantly to average blood glucose, glycaemic variability and cardiovascular risk. Carbohydrate counting is a method of insulin dosing that balances carbohydrate load to insulin dose using a fixed ratio. Many patients and current insulin pumps calculate insulin delivery for meals based on a linear carbohydrate-to-insulin relationship. It is our hypothesis that a non-linear relationship exists between the amounts of carbohydrate consumed and the insulin required to cover it. To document blood glucose exposure in response to increasing carbohydrate loads on fixed carbohydrate-to-insulin ratios. Five type 1 diabetic subjects receiving insulin pump therapy with good control were recruited. Morning basal rates and carbohydrate- to-insulin ratios were optimised. A Medtronic glucose sensor was used for 5 days to collect data for area-under-the-curve (AUC) analysis, during which standardised meals of increasing carbohydrate loads were consumed. Increasing carbohydrate loads using a fixed carbohydrate-to-insulin ratio resulted in increasing glucose AUC. The relationship was found to be exponential rather than linear. Late postprandial hypoglycaemia followed carbohydrate loads of >60 g and this was often followed by rebound hyperglycaemia that lasted >6 hours. A non-linear relationship exists between carbohydrates consumed and the insulin required to cover them. This has implications for control of postprandial blood sugars, especially when consuming large carbohydrate loads. Further studies are required to look at the optimal ratios, duration and type of insulin boluses required to cover increasing carbohydrate loads.

A novel pen-based Bluetooth-enabled insulin delivery system with insulin dose tracking and advice.

PubMed

Bailey, Timothy S; Stone, Jenine Y

2017-05-01

Diabetes is growing in prevalence internationally. As more individuals require insulin as part of their treatment, technology evolves to optimize delivery, improve adherence, and reduce dosing errors. Insulin pens outperform vial and syringe in simplicity, dosing accuracy, and user preference. Bolus advisors improve dosing confidence and treatment adherence. The InPen System offers a novel approach to treatment via a wireless pen that syncs to a mobile application featuring a bolus advisor, enabling convenient insulin dose tracking and more accurate bolus advice among other features. Areas covered: Existing technology for insulin delivery and bolus advice are reviewed. The mechanics and functionality of the InPen device are delineated. Findings from formative testing and usability studies of the InPen system are reported. Future directions for the InPen system in the treatment of diabetes are discussed. Expert opinion: Diabetes management is complex and largely data-driven. The InPen System offers a promising new opportunity to avail insulin pen-users of features known to improve treatment efficacy, which have otherwise primarily been available to those using pumps. Given that the majority of insulin users do not use insulin pumps, the InPen System is poised to improve glucose control in a significant portion of the diabetes population.

Assessing the effectiveness of a 3-month day-and-night home closed-loop control combined with pump suspend feature compared with sensor-augmented pump therapy in youths and adults with suboptimally controlled type 1 diabetes: a randomised parallel study protocol

PubMed Central

Bally, Lia; Thabit, Hood; Tauschmann, Martin; Allen, Janet M; Hartnell, Sara; Wilinska, Malgorzata E; Exall, Jane; Huegel, Viki; Sibayan, Judy; Borgman, Sarah; Cheng, Peiyao; Blackburn, Maxine; Lawton, Julia; Elleri, Daniela; Leelarathna, Lalantha; Acerini, Carlo L; Campbell, Fiona; Shah, Viral N; Criego, Amy; Evans, Mark L; Dunger, David B; Kollman, Craig; Bergenstal, Richard M; Hovorka, Roman

2017-01-01

Introduction Despite therapeutic advances, many individuals with type 1 diabetes are unable to achieve tight glycaemic target without increasing the risk of hypoglycaemia. The objective of this study is to determine the effectiveness of a 3-month day-and-night home closed-loop glucose control combined with a pump suspend feature, compared with sensor-augmented insulin pump therapy in youths and adults with suboptimally controlled type 1 diabetes. Methods and analysis The study adopts an open-label, multi-centre, multi-national (UK and USA), randomised, single-period, parallel design and aims for 84 randomised patients. Participants are youths (6–21 years) or adults (>21 years) with type 1 diabetes treated with insulin pump therapy and suboptimal glycaemic control (glycated haemoglobin (HbA1c) ≥7.5% (58 mmol/mol) and ≤10% (86 mmol/mol)). Following a 4-week run-in period, eligible participants will be randomised to a 3-month use of automated closed-loop insulin delivery combined with pump suspend feature or to sensor-augmented insulin pump therapy. Analyses will be conducted on an intention-to-treat basis. The primary outcome is the time spent in the target glucose range from 3.9 to 10.0 mmol/L based on continuous glucose monitoring levels during the 3-month free-living phase. Secondary outcomes include HbA1c at 3 months, mean glucose, time spent below and above target; time with glucose levels <3.5 and <2.8 mmol/L; area under the curve when sensor glucose is <3.5 mmol/L, time with glucose levels >16.7 mmol/L, glucose variability; total, basal and bolus insulin dose and change in body weight. Participants’ and their families’ perception in terms of lifestyle change, daily diabetes management and fear of hypoglycaemia will be evaluated. Ethics and dissemination Ethics/institutional review board approval has been obtained. Before screening, all participants/guardians will be provided with oral and written information about the trial. The study will be disseminated by peer-reviewed publications and conference presentations. Trial registration number NCT02523131; Pre-results. PMID:28710224

Family perceptions of insulin pump adverse events in children and adolescents.

PubMed

Wheeler, Benjamin J; Donaghue, Kim C; Heels, Kristine; Ambler, Geoffrey R

2014-04-01

Insulin pumps (for continuous subcutaneous insulin infusion [CSII]) are used widely in type 1 diabetes mellitus. Although there has been considerable study of outcomes, there are few recent data on CSII-associated adverse events and no data on family perceptions of adverse events and their confidence in dealing with them. We approached all families of children and adolescents ≤ 19 years of age on CSII attending the diabetes clinic over a 16-week clinic cycle. Participants completed a retrospective questionnaire examining issues over the previous 12 months. Data on pump adverse events as well as answers to questions pertaining to education and confidence were collected. Our survey received a response rate of 99%, with 235 of the 238 families approached participating. In the preceding 12 months, 104 of 230 (45%) had reported at least one pump-related adverse event (either mechanical or set-related), with an associated 52 of 229 (23%) resulting in pump replacement. This equated to a minimum incidence density of 53 adverse events/100 person-years. Additionally, 18 of 230 (8%) reported a hospital admission or emergency department attendance as a consequence. Pump malfunction and infusion set/site failures were the most common events reported, with one or more events in 58 of 104 (56%) and 47 of 104 (45%), respectively. Adverse events, excluding set/site failures, were associated with older age (13.1 ± 3.4 years vs. 11.9 ± 4 years; P = 0.02). This is the first study to look at family perceptions of adverse events while using modern CSII. It highlights a high self-reported rate of CSII-related adverse events, pump replacement, and subsequent presentation to the hospital. Potential areas for additional targeted education are identified. Further prospective study examining pump adverse event characteristics and incidence is warranted.

Accuracy of a New Patch Pump Based on a Microelectromechanical System (MEMS) Compared to Other Commercially Available Insulin Pumps

PubMed Central

Borot, Sophie; Franc, Sylvia; Cristante, Justine; Penfornis, Alfred; Benhamou, Pierre-Yves; Guerci, Bruno; Hanaire, Hélène; Renard, Eric; Reznik, Yves; Simon, Chantal

2014-01-01

The JewelPUMP™ (JP) is a new patch pump based on a microelectromechanical system that operates without any plunger. The study aimed to evaluate the infusion accuracy of the JP in vitro and in vivo. For the in vitro studies, commercially available pumps meeting the ISO standard were compared to the JP: the MiniMed® Paradigm® 712 (MP), Accu-Chek® Combo (AC), OmniPod® (OP), Animas® Vibe™ (AN). Pump accuracy was measured over 24 hours using a continuous microweighing method, at 0.1 and 1 IU/h basal rates. The occlusion alarm threshold was measured after a catheter occlusion. The JP, filled with physiological serum, was then tested in 13 patients with type 1 diabetes simultaneously with their own pump for 2 days. The weight difference was used to calculate the infused insulin volume. The JP showed reduced absolute median error rate in vitro over a 15-minute observation window compared to other pumps (1 IU/h): ±1.02% (JP) vs ±1.60% (AN), ±1.66% (AC), ±2.22% (MP), and ±4.63% (OP), P < .0001. But there was no difference over 24 hours. At 0.5 IU/h, the JP was able to detect an occlusion earlier than other pumps: 21 (19; 25) minutes vs 90 (85; 95), 58 (42; 74), and 143 (132; 218) minutes (AN, AC, MP), P < .05 vs AN and MP. In patients, the 24-hour flow error was not significantly different between the JP and usual pumps (–2.2 ± 5.6% vs –0.37 ± 4.0%, P = .25). The JP was found to be easier to wear than conventional pumps. The JP is more precise over a short time period, more sensitive to catheter occlusion, well accepted by patients, and consequently, of potential interest for a closed-loop insulin delivery system. PMID:25079676

Successful treatment of young infants presenting neonatal diabetes mellitus with continuous subcutaneous insulin infusion before genetic diagnosis.

PubMed

Rabbone, Ivana; Barbetti, Fabrizio; Marigliano, Marco; Bonfanti, Riccardo; Piccinno, Elvira; Ortolani, Federica; Ignaccolo, Giovanna; Maffeis, Claudio; Confetto, Santino; Cerutti, Franco; Zanfardino, Angela; Iafusco, Dario

2016-08-01

Neonatal diabetes mellitus (NDM) is defined as hyperglycemia and impaired insulin secretion with onset within 6 months of birth. While rare, NDM presents complex challenges regarding the management of glycemic control. The availability of continuous subcutaneous insulin infusion pumps (CSII) in combination with continuous glucose monitoring systems (CGM) provides an opportunity to monitor glucose levels more closely and deliver insulin more safely. We report four cases of young infants with NDM successfully treated with CSII and CGM. Moreover, in two cases with Kir 6.2 mutation, we describe the use of CSII in switching therapy from insulin to sulfonylurea treatment. Insulin pump requirement for the 4 neonatal diabetes cases was the same regardless of disease pathogenesis and c-peptide levels. No dilution of insulin was needed. The use of an integrated CGM system helped in a more precise control of BG levels with the possibility of several modifications of insulin basal rates. Moreover, as showed in the first two case-reports, when the treatment was switched from insulin to glibenclamide, according to identification of Kir 6.2 mutation and diagnosis of NPDM, the CSII therapy demonstrated to be helpful in allowing gradual insulin suspension and progressive introduction of sulfonylurea. During the neonatal period, the use of CSII therapy is safe, more physiological, accurate and easier for the insulin administration management. Furthermore, CSII therapy is safe during the switch of therapy from insulin to glibenclamide for infants with permanent neonatal diabetes mellitus.

Smiths Medical Medfusion 3010a syringe pump may overinfuse if software is outdated.

PubMed

2010-04-01

Smiths Medical Medfusion 3010a syringe pumps that aren't equipped with the latest software version (2.0.6) could overinfuse if the "recall last settings" function is used following an infusion in volume/time mode. If your facility has pumps equipped with software versions older than 2.0.6, contact Smiths Medical to obtain an upgrade.

New technologies in the treatment of type 1 diabetes.

PubMed

Schmidt, Signe

2013-11-01

Type 1 diabetes is a chronic condition characterized by insufficient production of insulin, a hormone needed for proper control of blood glucose levels. People with type 1 diabetes must monitor their blood glucose throughout the day using a glucose meter or a continuous glucose monitor, calculate how much insulin is needed to maintain normal blood glucose levels, and administer the insulin dose by pen injection or insulin pump infusion into the subcutaneous tissue. In recent years, several new technologies for the treatment of type 1 diabetes have been developed. This PhD thesis covers two studies of the effects of commercially available technologies--sensor-augmented pump therapy and automated insulin bolus calculators--when used in clinical practice. Both studies demonstrated that these technologies have the potential to improve diabetes care. In addition, two in-clinic studies related to emerging technologies--closed-loop glucose control and virtual simulation environments--are included in the thesis. The results of these experiments provided proof of concept and will serve as a basis for further research in these fields.

Evaluation of the Effect of Carbohydrate Intake on Postprandial Glucose in Patients With Type 1 Diabetes Treated With Insulin Pumps.

PubMed

James, Mariel L; Green, Louisa; Amiel, Stephanie A; Choudhary, Pratik

2016-11-01

It has been suggested that dietary freedom in functional insulin therapy may be detrimental to glycemic control in type 1 diabetes. This study evaluates the effect of carbohydrate intake on glycemic control and postprandial blood glucose concentrations. Insulin pump data from 148 adults with type 1 diabetes, trained in functional insulin therapy, using pumps for ≥6 months, with ≥2 weeks of consecutive downloaded data, ≥80% use of a bolus calculator, ≥3 capillary blood glucose tests/day, and a concurrent HbA1C, were analyzed. More detailed periprandial data (pre- and postmeal glucose, carbohydrate intake, insulin bolus) were collected from a subset of 105 downloads (3495 meals). Mean (± SD) age of contributors was 43 ± 13 years, HbA1C 7.84% ± 0.93 (62.19 mmol/mol); daily carbohydrate intake 166 ± 71 g. HbA1C reduced with increased meals/day (r = -.370, P < .0005) and increased with mean carbohydrate content/meal (r = .198, P = .043). However, total daily carbohydrate intake had a weak but significant negative association with HbA1C (r = -.181, P = .027). There was no association between standard deviation of carbohydrate intake and HbA1C (r = .021, P = .802) or between meal carbohydrate content and postprandial change in blood glucose (r = -.004, P = .939) for meals with early postprandial (1-3 hours; n = 390) readings. There was a weak positive correlation (r = .184, P = .008) between meal carbohydrate content and late (4-7 hours; n = 390) postprandial readings. With appropriate training, patients using insulin pumps can accommodate a flexible diet with variable carbohydrate intake, without detriment to glycemic control. However, large carbohydrate meals may contribute to poorer outcomes, through impact on late postprandial glycemia. © 2016 Diabetes Technology Society.

Position Statement on the management of continuous subcutaneous insulin infusion (CSII): The Italian Lazio experience.

PubMed

Maurizi, Anna R; Suraci, Concetta; Pitocco, Dario; Schiaffini, Riccardo; Tubili, Claudio; Morviducci, Lelio; Giordano, Renato; Manfrini, Silvia; Lauro, Davide; Frontoni, Simona; Pozzilli, Paolo; Buzzetti, Raffaella

2016-01-01

This document has been developed by a group of Italian diabetologists with extensive experience in continuous subcutaneous insulin infusion (CSII) therapy to provide indications for the clinical management of CSII in diabetic patients (both type 1 and type 2) based on delivery mode operating in Italy. Although the potential benefits of pump therapy in achieving glycemic goals is now accepted, such results cannot be obtained without specific knowledge and skills being conveyed to patients during ad hoc educational training. To ensure that these new technologies reach their full effectiveness, as demonstrated theoretically and clinically, a careful assessment of the overall therapeutic and educational process is required, in both qualitative and quantitative terms. Therefore, to ensure the cost-effectiveness of insulin pump therapy and to justify reimbursement of therapy costs by the National Health System in Italy, in this article we present a model for diabetes and healthcare centers to follow that provides for different levels of expertise in the field of CSII therapy. This model will guarantee the provision of excellent care during insulin pump therapies, thus representing the basis for a successful outcome and expansion of this form of insulin treatment in patients with diabetes while also keeping costs under control. © 2015 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Insulin therapy in neonatal diabetes mellitus: a review of the literature.

PubMed

Rabbone, Ivana; Barbetti, Fabrizio; Gentilella, Raffaella; Mossetto, Gilberto; Bonfanti, Riccardo; Maffeis, Claudio; Iafusco, Dario; Piccinno, Elvira

2017-07-01

Neonatal diabetes mellitus (NDM) is a rare disorder, and guidance is limited regarding its optimal management. We reviewed insulin usage in NDM, with a focus on continuous subcutaneous insulin infusion (CSII). A PubMed search identified 40 reports of patients with NDM treated with insulin published between 1994 and 2016. Data concerning treatment of NDM are limited. CSII resolves some of the issues associated with insulin therapy in neonates. No clinical trials of CSII in NDM have been reported. Case reports suggest that CSII is a safe and effective means of treating NDM. CSII was initiated to improve glycaemic control, for practicality and convenience, and to overcome difficulties associated with the maintenance of long-term intravenous catheters. CSII can provide better glycaemic control than multiple daily injections, with few hypoglycaemic events. Continuous glucose monitoring integrated with the pump helps provide more precise control of blood glucose levels. CSII generally uses short-acting insulin or rapid-acting insulin analogues, and those that are approved for use in neonates appear to be appropriate for the treatment of NDM using an insulin pump. Information from case reports indicates that CSII is safe and effective for the management of NDM. Copyright © 2017 Elsevier B.V. All rights reserved.

The nature and meaning of insulin pump use in emerging adults with type 1 diabetes.

PubMed

Hood, Donna G; Duke, Gloria

2015-05-01

Objective. The purpose of this study is to investigate the meaning of living with an insulin pump for the management of type 1 diabetes during the period of emerging adulthood. Through a phenomenological narrative, this study contributes to the reflective understanding of the everyday life experiences of this population. Methods. A hermeneutic phenomenological design was used for this study of nine emerging adults (aged 19-24 years). Data were generated through face-to-face interviews and analyzed using the phenomenological approach of Max van Manen. Results. Four themes represent the essence of the day-to-day experiences of these emerging adults: seeking control, becoming responsible, staying connected, and accepting me. Conclusions. An in-depth understanding of the meaning of daily experiences with insulin pump technology has the potential to promote a developmentally appropriate approach to this age-group. The human understanding gained through this study is essential to the development of evidence-based practice guidelines and resources for this vulnerable population.

Impact of deprivation, ethnicity, and insulin pump therapy on developmental trajectories of diabetes control in COB type 1 diabetes.

PubMed

Viner, Russell M; White, Billy; Amin, Rakesh; Peters, Catherine; Khanolkar, Amal; Christie, Deborah; Hindmarsh, Peter C

2017-08-01

There is marked variation in diabetes outcomes for children and adolescents across the UK. We used modelling techniques to examine the independent contributions of deprivation, ethnicity, insulin pump use, and health service use on HbA 1c trajectories across adolescence. Prospective data from a large UK Paediatric & Adolescent Diabetes Service on subjects with type 1 diabetes (T1D) aged 9-17 years from January 2008 to December 2013: 2560 HbA 1c datapoints were available on 384 patients [193 (50.4%) female]. Sequential multilevel growth models assessed the effects of sex, duration of diabetes, deprivation, ethnicity, insulin pump use, and health service use on HbA 1c . Growth mixture models were used to identify discrete HbA 1c trajectories across adolescence. Mean clinic HbA 1c decreased from 2008 to 2013 by 0.122% (95% confidence interval: 0.034, 0.210; P = .007) per year. The optimal multilevel growth model showed mean HbA 1c increased with age (B = 0.414, P < .0001), and that mean HbA 1c was predicted by white/British ethnicity (B = -0.748, P = .004), clinic visits (B = 0.041, P = .04), and pump use (B = -0.568, P < .0001) but not deprivation. The optimal mixture model was a four trajectory group solution, with 45.1% in Good Control, 39.6% with Deteriorating Control, 6.5% with Rapidly Deteriorating Control, and 8.8% in Poor Control across adolescence. Only pump use predicted trajectory group membership, being protective against membership of all other trajectories compared with Good Control. Increasing uptake of insulin pumps and ensuring access to health services are likely to be the most effective means of reducing inequalities in outcomes of T1D in children and young people. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Insulin pumps and insulin quality--requirements and problems.

PubMed

Brange, J; Havelund, S

1983-01-01

In developing insulin solution suitable for delivery devices the chemical and biological stability, as well as the physical stability, must be taken into consideration. Addition of certain mono- and disaccharides increases the physical stability of neutral insulin solutions, but concurrently the chemical and biological stability decrease to an unacceptable degree. Addition of Ca-ions in low concentrations offers a physiologically acceptable method for stabilizing neutral insulin solutions against heat precipitation without affecting the quality, including the chemical and biological stability.

Comparison Between Individually and Group-Based Insulin Pump Initiation by Time-Driven Activity-Based Costing

PubMed Central

Ridderstråle, Martin

2017-01-01

Background: Depending on available resources, competencies, and pedagogic preference, initiation of insulin pump therapy can be performed on either an individual or a group basis. Here we compared the two models with respect to resources used. Methods: Time-driven activity-based costing (TDABC) was used to compare initiating insulin pump treatment in groups (GT) to individual treatment (IT). Activities and cost drivers were identified, timed, or estimated at location. Medical quality and patient satisfaction were assumed to be noninferior and were not measured. Results: GT was about 30% less time-consuming and 17% less cost driving per patient and activity compared to IT. As a batch driver (16 patients in one group) GT produced an upward jigsaw-shaped accumulative cost curve compared to the incremental increase incurred by IT. Taking the alternate cost for those not attending into account, and realizing the cost of opportunity gained, suggested that GT was cost neutral already when 5 of 16 patients attended, and that a second group could be initiated at no additional cost as the attendance rate reached 15:1. Conclusions: We found TDABC to be effective in comparing treatment alternatives, improving cost control and decision making. Everything else being equal, if the setup is available, our data suggest that initiating insulin pump treatment in groups is far more cost effective than on an individual basis and that TDABC may be used to find the balance point. PMID:28366085

Use of a plastic insulin dosage guide to correct blood glucose levels out of the target range and for carbohydrate counting in subjects with type 1 diabetes.

PubMed

Kaufman, F R; Halvorson, M; Carpenter, S

1999-08-01

To improve glycemic control, a hand-held plastic Insulin Dosage Guide was developed to correct blood glucose levels outside of the target range. Protocol 1: Some 40 children (mean age 10.6+/-4.6 years) were randomly assigned for 3 months to use a written-on-paper algorithm or the Insulin Dosage Guide to correct abnormal blood glucose levels. Mean HbA1c and blood glucose levels and time to teach insulin dosage correction were compared. Protocol 2: The Insulin Dosage Guide was used by 83 subjects (mean age 11.4+/-4.3 years) for 1 year, and mean HbA1c levels, blood glucose levels, and number of consecutive high blood glucose values taken before and after the year were compared. Protocol 3: Some 20 patients (mean age 10.1+/-3.7 years) using rapid-acting insulin and 64 patients (mean age 15.9+/-3.6 years) using an insulin pump and rapid-acting insulin used the Insulin Dosage Guide and had mean blood glucose levels, HbA1c, and percentage of blood glucose levels outside of the target range determined. Protocol 1: There was a significant reduction in mean HbA1c (P = 0.04) and blood glucose levels (P = 0.05) and in the time needed to teach how to correct blood glucose values using the Insulin Dosage Guide compared with the paper algorithm. Protocol 2: There was a decrease in mean HbA1c levels (P = 0.0001) and a decrease in the mean number of consecutive blood glucose levels (P = 0.001) over the 1-year time period. Protocol 3: With rapid-acting insulin, there was a significant increase in the percentage of blood glucose levels within the target range (1 month, P = 0.04; at 3 months, P = 0.03). With the insulin pump, there was a high rate (90%) of blood glucose levels in the target range during pump initiation when the Insulin Dosage Guide was used. This inexpensive hand-held plastic card, which is portable and easy to use, may help patients improve glycemia and successfully manage diabetes.

Open-loop glucose control: Automatic IOB-based super-bolus feature for commercial insulin pumps.

PubMed

Rosales, Nicolás; De Battista, Hernán; Vehí, Josep; Garelli, Fabricio

2018-06-01

Although there has been significant progress towards closed-loop type 1 diabetes mellitus (T1DM) treatments, most diabetic patients still treat this metabolic disorder in an open-loop manner, based on insulin pump therapy (basal and bolus insulin infusion). This paper presents a method for automatic insulin bolus shaping based on insulin-on-board (IOB) as an alternative to conventional bolus dosing. The methodology presented allows the pump to generate the so-called super-bolus (SB) employing a two-compartment IOB dynamic model. The extra amount of insulin to boost the bolus and the basal cutoff time are computed using the duration of insulin action (DIA). In this way, the pump automatically re-establishes basal insulin when IOB reaches its basal level. Thus, detrimental transients caused by manual or a-priori computations are avoided. The potential of this method is illustrated via in-silico trials over a 30 patients cohort in single meal and single day scenarios. In the first ones, improvements were found (standard treatment vs. automatic SB) both in percentage time in euglycemia (75g meal: 81.9 ± 15.59 vs. 89.51 ± 11.95, ρ ≃ 0; 100g meal: 75.12 ± 18.23 vs. 85.46 ± 14.96, ρ ≃ 0) and time in hypoglecymia (75g meal: 5.92 ± 14.48 vs. 0.97 ± 4.15, ρ=0.008; 100g meal: 9.5 ± 17.02 vs. 1.85 ± 7.05, ρ=0.014). In a single day scenario, considering intra-patient variability, the time in hypoglycemia was reduced (9.57 ± 14.48 vs. 4.21 ± 6.18, ρ=0.028) and improved the time in euglycemia (79.46 ± 17.46 vs. 86.29 ± 11.73, ρ=0.007). The automatic IOB-based SB has the potential of a better performance in comparison with the standard treatment, particularly for high glycemic index meals with high carbohydrate content. Both glucose excursion and time spent in hypoglycemia were reduced. Copyright © 2018 Elsevier B.V. All rights reserved.

Carbohydrate-to-insulin ratio is estimated from 300-400 divided by total daily insulin dose in type 1 diabetes patients who use the insulin pump.

PubMed

Kuroda, Akio; Yasuda, Tetsuyuki; Takahara, Mitsuyoshi; Sakamoto, Fumie; Kasami, Ryuichi; Miyashita, Kazuyuki; Yoshida, Sumiko; Kondo, Eri; Aihara, Ken-ichi; Endo, Itsuro; Matsuoka, Taka-aki; Kaneto, Hideaki; Matsumoto, Toshio; Shimomura, Iichiro; Matsuhisa, Munehide

2012-11-01

To optimize insulin dose using insulin pump, basal and bolus insulin doses are widely calculated from total daily insulin dose (TDD). It is recommended that total daily basal insulin dose (TBD) is 50% of TDD and that the carbohydrate-to-insulin ratio (CIR) equals 500 divided by TDD. We recently reported that basal insulin requirement is approximately 30% of TDD. We therefore investigated CIR after adjustment of the proper basal insulin rate. Forty-five Japanese patients with type 1 diabetes were investigated during several weeks of hospitalization. The patients were served standard diabetes meals (25-30 kcal/kg of ideal body weight). Each meal omission was done to confirm basal insulin rate. Target blood glucose level was set at 100 and 150 mg/dL before and 2 h after each meal, respectively. After the basal insulin rate was fixed and target blood glucose levels were achieved, TBD, CIR, TDD, and their products were determined. Mean (±SD) blood glucose levels before and 2 h after meals were 121±47 and 150±61 mg/dL, respectively. TDD was 31.5±9.0 U, and TBD was 27.0±6.5% of TDD. CIR×TDD of breakfast was significantly lower than those of lunch and supper (288±73 vs. 408±92 and 387±83, respectively; P<0.01). CIR has diurnal variance and is estimated from the formula CIR=300/TDD at breakfast or CIR=400/TDD at lunch and supper in type 1 diabetes patients. These results indicate that the insulin dose has been underestimated by using previously established calculations.

Assessing the effectiveness of a 3-month day-and-night home closed-loop control combined with pump suspend feature compared with sensor-augmented pump therapy in youths and adults with suboptimally controlled type 1 diabetes: a randomised parallel study protocol.

PubMed

Bally, Lia; Thabit, Hood; Tauschmann, Martin; Allen, Janet M; Hartnell, Sara; Wilinska, Malgorzata E; Exall, Jane; Huegel, Viki; Sibayan, Judy; Borgman, Sarah; Cheng, Peiyao; Blackburn, Maxine; Lawton, Julia; Elleri, Daniela; Leelarathna, Lalantha; Acerini, Carlo L; Campbell, Fiona; Shah, Viral N; Criego, Amy; Evans, Mark L; Dunger, David B; Kollman, Craig; Bergenstal, Richard M; Hovorka, Roman

2017-07-13

Despite therapeutic advances, many individuals with type 1 diabetes are unable to achieve tight glycaemic target without increasing the risk of hypoglycaemia. The objective of this study is to determine the effectiveness of a 3-month day-and-night home closed-loop glucose control combined with a pump suspend feature, compared with sensor-augmented insulin pump therapy in youths and adults with suboptimally controlled type 1 diabetes. The study adopts an open-label, multi-centre, multi-national (UK and USA), randomised, single-period, parallel design and aims for 84 randomised patients. Participants are youths (6-21 years) or adults (>21 years) with type 1 diabetes treated with insulin pump therapy and suboptimal glycaemic control (glycated haemoglobin (HbA1c) ≥7.5% (58 mmol/mol) and ≤10% (86 mmol/mol)). Following a 4-week run-in period, eligible participants will be randomised to a 3-month use of automated closed-loop insulin delivery combined with pump suspend feature or to sensor-augmented insulin pump therapy. Analyses will be conducted on an intention-to-treat basis. The primary outcome is the time spent in the target glucose range from 3.9 to 10.0 mmol/L based on continuous glucose monitoring levels during the 3-month free-living phase. Secondary outcomes include HbA1c at 3 months, mean glucose, time spent below and above target; time with glucose levels <3.5 and <2.8 mmol/L; area under the curve when sensor glucose is <3.5 mmol/L, time with glucose levels >16.7 mmol/L, glucose variability; total, basal and bolus insulin dose and change in body weight. Participants' and their families' perception in terms of lifestyle change, daily diabetes management and fear of hypoglycaemia will be evaluated. Ethics/institutional review board approval has been obtained. Before screening, all participants/guardians will be provided with oral and written information about the trial. The study will be disseminated by peer-reviewed publications and conference presentations. NCT02523131; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Twenty-four-hour simultaneous subcutaneous basal-bolus administration of insulin and amylin in adolescents with type 1 diabetes decreases postprandial hyperglycemia

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to examine the effect of continuous subcutaneous (sc) replacement of amylin and insulin for a 24-h period on glucose homeostasis in adolescents with type 1 diabetes. Thirteen adolescents with type 1 diabetes on insulin pump therapy participated in a randomized, controll...

Effects of glargine insulin on glycemic control in patients with diabetes mellitus type II undergoing off-pump coronary artery bypass graft.

PubMed

Gandhi, Hemang; Sarvaia, Alpesh; Malhotra, Amber; Acharya, Himanshu; Shah, Komal; Rajavat, Jeevraj

2018-01-01

The prevalence of diabetes mellitus in patients requiring coronary artery bypass grafting (CABG) is noticeably high (20%-30%). These patients have inferior perioperative outcome, reduced long-term survival, and high risk of recurrent episodes of angina. To improve perioperative outcome surgical unit defined satisfactory glycemic control is desired during this period. Hence, the aim of our study is to compare the efficacy of glargine insulin combination with continuous human insulin infusion for perioperative glycemic control in patients with diabetes undergoing CABG. Fifty Patients, who were posted for off-pump CABG with diabetes mellitus type II, were randomized in two group, Group I normal saline + human insulin infusion during the perioperative period, Group II (glargine group): Glargine + human insulin infusion during perioperative period. During surgery and in the postoperative period, random blood sugar and human insulin requirement are significantly higher in control group than glargine group. Other infection, step-up antibiotics, intensive care unit (ICU) stay, and hospital stay were significantly higher in control groups in postoperative period. Our study results suggest that glargine effectively manages blood glucose level with significantly greater control over postoperative morbidity.

A sophisticated programmable miniaturised pump for insulin delivery.

PubMed

Klein, J C; Slama, G

1980-09-01

We have conceived a truly pre-programmable infusion system usable for intravenous administration of insulin in diabetic subjects. The original system has been built into a small, commercially available, syringe-pump of which only the case and the mechanical parts have been kept. The computing until has a timer, a programmable memory of 512 words by 8 bits and a digital-to-frequency converter to run the motor which drives the syringe. The memory contains 8 profiles of insulin injections stored in digital form over 64 words. Each profile is selected by the patient before eating according to the carbohydrate content of the planned meal and last about two hours, starting from and returning to the basal rate of insulin, at which it remains until next profile selection. Amount, profiles and duration of insulin injection are either mean values deduced from previous studies with a closed-loop artificial pancreas or personally fitted values; they are stored in an instantly replaceable memory cell. This device allows the patient to choose the time, nature and amount of his food intake.

Continuous glucose monitoring and hypoglycemia unawareness in type 1 diabetes: a pilot study.

PubMed

Zalzali, Mohamed; Houdelet-Guerinot, Valérie; Socquard, Eric; Thierry, Aurore; Delemer, Brigitte; Lukas-Croisier, Céline

2017-09-01

Looking for strict normoglycemia in type 1 diabetes increases the risk of hypoglycemia, exposing to hypoglycemia unawareness. It has been shown that the early correction of hypoglycemia can help recovering the perception of hypoglycemia. The purpose of this prospective study was to assess the value of sensor-augmented insulin-pump therapy to treat hypoglycemia unawareness. Eleven patients with type 1 diabetes and partial or total hypoglycemia unawareness received sensor-augmented insulin-pump therapy combined to the low blood glucose-suspend feature (Paradigm® Veo™ pump and Enlite® sensors) for three months. Eighty per cent of the patients improved their hypoglycemia unawareness with an increase in the hypoglycemia perception threshold of 31 mg/dL as evaluated by blinded continuous glucose monitoring. These results were correlated to a self-assessment quiz evaluation. Results were sustained at six months (three months after patients stopped using the system). Sensitive neuropathy, untreated hypoglycemia and the area under the curve for hypoglycemia events were associated with less chance of recovery. These devices were globally considered by the patients as simple to use, with no major disadvantages and only a single withdrawal occurred. Sensor-augmented insulin-pump therapy should be considered as a possible treatment of hypoglycemia unawareness.

Insulin and leptin relations in obesity: a multimedia approach.

PubMed

Yokaichiya, Daniela K; Galembeck, Eduardo; Torres, Bayardo B; Da Silva, José Antônio; de Araujo, Daniele R

2008-09-01

Obesity has been recognized as a worldwide public health problem. It significantly increases the chances of developing several diseases, including Type II diabetes. The roles of insulin and leptin in obesity involve reactions that can be better understood when they are presented step by step. The aim of this work was to design software with data from some of the most recent publications on obesity, especially those concerning the roles of insulin and leptin in this metabolic disturbance. The most notable characteristic of this software is the use of animations representing the cellular response together with the presentation of recently discovered mechanisms on the participation of insulin and leptin in processes leading to obesity. The software was field tested in the Biochemistry of Nutrition web-based course. After using the software and discussing its contents in chatrooms, students were asked to answer an evaluation survey about the whole activity and the usefulness of the software within the learning process. The teaching assistants (TA) evaluated the software as a tool to help in the teaching process. The students' and TAs' satisfaction was very evident and encouraged us to move forward with the software development and to improve the use of this kind of educational tool in biochemistry classes.

Cost-effectiveness of insulin pumps compared with multiple daily injections both provided with structured education for adults with type 1 diabetes: a health economic analysis of the Relative Effectiveness of Pumps over Structured Education (REPOSE) randomised controlled trial.

PubMed

Pollard, Daniel John; Brennan, Alan; Dixon, Simon; Waugh, Norman; Elliott, Jackie; Heller, Simon; Lee, Ellen; Campbell, Michael; Basarir, Hasan; White, David

2018-04-07

To assess the long-term cost-effectiveness of insulin pumps and Dose Adjustment for Normal Eating (pumps+DAFNE) compared with multiple daily insulin injections and DAFNE (MDI+DAFNE) for adults with type 1 diabetes mellitus (T1DM) in the UK. We undertook a cost-utility analysis using the Sheffield Type 1 Diabetes Policy Model and data from the Relative Effectiveness of Pumps over Structured Education (REPOSE) trial to estimate the lifetime incidence of diabetic complications, intervention-based resource use and associated effects on costs and quality-adjusted life years (QALYs). All economic analyses took a National Health Service and personal social services perspective and discounted costs and QALYs at 3.5% per annum. A probabilistic sensitivity analysis was performed on the base case. Further uncertainties in the cost of pumps and the evidence used to inform the model were explored using scenario analyses. Eight diabetes centres in England and Scotland. Adults with T1DM who were eligible to receive a structured education course and did not have a strong clinical indication or a preference for a pump. Pumps+DAFNE. MDI+DAFNE. Incremental costs, incremental QALYs gained and incremental cost-effectiveness ratios (ICERs). Compared with MDI+DAFNE, pumps+DAFNE was associated with an incremental discounted lifetime cost of +£18 853 (95% CI £6175 to £31 645) and a gain in discounted lifetime QALYs of +0.13 (95% CI -0.70 to +0.96). The base case mean ICER was £142 195 per QALY gained. The probability of pump+DAFNE being cost-effective using a cost-effectiveness threshold of £20 000 per QALY gained was 14.0%. All scenario and subgroup analyses examined indicated that the ICER was unlikely to fall below £30 000 per QALY gained. Our analysis of the REPOSE data suggests that routine use of pumps in adults without an immediate clinical need for a pump, as identified by National Institute for Health and Care Excellence, would not be cost-effective. ISRCTN61215213. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Home Use of Day-and-Night Hybrid Closed-Loop Insulin Delivery in Suboptimally Controlled Adolescents With Type 1 Diabetes: A 3-Week, Free-Living, Randomized Crossover Trial.

PubMed

Tauschmann, Martin; Allen, Janet M; Wilinska, Malgorzata E; Thabit, Hood; Acerini, Carlo L; Dunger, David B; Hovorka, Roman

2016-11-01

This study evaluated the feasibility, safety, and efficacy of day-and-night hybrid closed-loop insulin delivery in adolescents with type 1 diabetes under free-living conditions. In an open-label randomized crossover study, 12 suboptimally controlled adolescents on insulin pump therapy (mean ± SD age 14.6 ± 3.1 years; HbA 1c 69 ± 8 mmol/mol [8.5 ± 0.7%]; duration of diabetes 7.8 ± 3.5 years) underwent two 21-day periods in which hybrid closed-loop insulin delivery was compared with sensor-augmented insulin pump therapy in random order. During the closed-loop intervention, a model predictive algorithm automatically directed insulin delivery between meals and overnight. Participants used a bolus calculator to administer prandial boluses. The proportion of time that sensor glucose was in the target range (3.9-10 mmol/L; primary end point) was increased during the closed-loop intervention compared with sensor-augmented insulin pump therapy by 18.8 ± 9.8 percentage points (mean ± SD; P < 0.001), the mean sensor glucose level was reduced by 1.8 ± 1.3 mmol/L (P = 0.001), and the time spent above target was reduced by 19.3 ± 11.3 percentage points (P < 0.001). The time spent with sensor glucose levels below 3.9 mmol/L was low and comparable between interventions (median difference 0.4 [interquartile range -2.2 to 1.3] percentage points; P = 0.33). Improved glucose control during closed-loop was associated with increased variability of basal insulin delivery (P < 0.001) and an increase in the total daily insulin dose (53.5 [39.5-72.1] vs. 51.5 [37.6-64.3] units/day; P = 0.006). Participants expressed positive attitudes and experience with the closed-loop system. Free-living home use of day-and-night closed-loop in suboptimally controlled adolescents with type 1 diabetes is safe, feasible, and improves glucose control without increasing the risk of hypoglycemia. Larger and longer studies are warranted. © 2016 by the American Diabetes Association.

Psychological barriers to optimal insulin therapy: more concerns in adolescent females than males

PubMed Central

Wisting, Line; Bang, Lasse; Skrivarhaug, Torild; Dahl-Jørgensen, Knut; Rø, Øyvind

2016-01-01

Objective The aim of this study is to investigate psychological barriers (illness perceptions, insulin beliefs, and coping strategies) to optimal insulin therapy among adolescents with type 1 diabetes (T1D), with a specific focus on gender differences and mode of treatment (insulin pump vs pen). Methods A total of 105 males and females (12–20 years) participated in this study. The Brief Illness Perception Questionnaire, the Beliefs about Medicines Questionnaire, and the Adolescent Coping Orientation for Problem Experiences were completed. Additionally, diabetes clinical data were collected by the Norwegian Childhood Diabetes Registry. Results Females had significantly more negative illness perceptions than males on all dimensions (p<0.05), with moderate-to-large effect sizes. Regarding insulin beliefs, females scored significantly higher than males on insulin concern (p<0.001), indicating more concerns about insulin. There were no significant gender differences on perceptions of insulin necessity. Finally, females scored significantly higher on the coping strategies being social and solving family problems (p<0.01), indicating more positive coping among females than males for these subscales. In terms of treatment mode, the only statistically significant difference in the psychological aspects was for the illness perception treatment control, with patients using insulin pen reporting more negative perceptions on this dimension than patients using insulin pump. Conclusions Addressing psychological aspects may be a clinically important supplement to standard somatic T1D care. The consistent finding of gender differences across the psychological measures implies that a tailored treatment approach for males and females with T1D may be warranted. PMID:27403325

[New developments in the treatment and monitoring of type 1 diabetes mellitus].

PubMed

Otto-Buczkowska, Ewa; Jarosz-Chobot, Przemysława; Tucholski, Krzysztof

2008-01-01

In recent years, insulin analogues are the benefits of the use in functional intensive insulin therapy for the treatment of diabetes. Shortacting insulin (lispro, aspart and glulisine) and long-acting insulin (glargine and detemir) have been developed for the management of diabetes. Short-acting insulin analogues are an alternative to regular human insulin before meals. These new short-acting insulin analogues show more rapid onset of activity and a shorter duration of action. As a result of these pharmacokinetic differences, an improved postprandial glycemic control is achieved, without increasing the risk of hypoglycemia. In addition, these insulin analogues can be administered immediately before a meal. The long-acting insulin analogues provide basal insulin levels for 24 h when administered once (glargine) or two (detemir) daily. Compared with previous intermediate- or long-acting conventional insulin, these insulins shows a flat profile of plasma insulin levels . The use of these long-acting insulin analogues appears to be associated with a reduced incidence of hypoglycemia, especially at night. The availability of these new insulin analogues has the potential to significantly improve long-term control over blood glucose in diabetic patients. In recent years more and more frequently the method of multiple daily injections (MDI) of insulin is being replaced by the method of continuous subcutaneous insulin infusion (CSII). It is the most physiological way to administer insulin. In recent years treatment with insulin pumps has been used more frequently in the pediatric patients and in the treatment of diabetes in pregnancy. Use of continuous glucose monitoring systems enables detection of glycemia fluctuations unrevealed by selfmonitoring of blood glucose, such as night hypoglycemias and early postprandial hyperglycemias. Real-time systems allow to reduce HbA1c levels and limit number of excursions. Non-invasive glucose measurement devices are introduced. Fully automated continuous glucose monitoring systems integrated with insulin pumps operating in closed-loop model, requiring no patient assistance, are still being researched. Commercially available systems operate in open-loop model, where the patient has to decide on administration and dose of insulin.

The Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE): study protocol for a cluster randomised controlled trial.

PubMed

White, David; Waugh, Norman; Elliott, Jackie; Lawton, Julia; Barnard, Katharine; Campbell, Michael J; Dixon, Simon; Heller, Simon

2014-09-03

People with type 1 diabetes (T1DM) require insulin therapy to sustain life, and need optimal glycaemic control to prevent diabetic ketoacidosis and serious long-term complications. Insulin is generally administered using multiple daily injections but can also be delivered using an infusion pump (continuous subcutaneous insulin infusion), a more costly option with benefits for some patients. The UK National Institute for Health and Care Excellence (NICE) recommend the use of pumps for patients with the greatest need, citing insufficient evidence to approve extension to a wider population. Far fewer UK adults use pumps than in comparable countries. Previous trials of pump therapy have been small and of short duration and failed to control for training in insulin adjustment. This paper describes the protocol for a large randomised controlled trial comparing pump therapy with multiple daily injections, where both groups are provided with high-quality structured education. A multicentre, parallel group, cluster randomised controlled trial among 280 adults with T1DM. All participants attended the week-long dose adjustment for normal eating (DAFNE) structured education course, and receive either multiple daily injections or pump therapy for 2 years. The trial incorporates a detailed mixed-methods psychosocial evaluation and cost-effectiveness analysis. The primary outcome will be the change in glycosylated haemoglobin (HbA1c) at 24 months in those participants whose baseline HbA1c is at or above 7.5% (58 mmol/mol). The key secondary outcome will be the proportion of participants reaching the NICE target of an HbA1c of 7.5% (58 mmol/mol) or less at 24 months. The protocol was approved by the Research Ethics Committee North West, Liverpool East and received Medicines and Healthcare products Regulatory Agency (MHRA) clinical trials authorisation. Each participating centre gave National Health Service R&D approval. We shall disseminate study findings to study participants and through peer reviewed publications and conference presentations, including lay user groups. ISRCTN 61215213. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Are Current Insulin Pumps Accessible to Blind and Visually Impaired People?

PubMed Central

Burton, Darren M.; Uslan, Mark M.; Blubaugh, Morgan V.; Clements, Charles W.

2009-01-01

Background In 2004, Uslan and colleagues determined that insulin pumps (IPs) on the market were largely inaccessible to blind and visually impaired persons. The objective of this study is to determine if accessibility status changed in the ensuing 4 years. Methods Five IPs on the market in 2008 were acquired and analyzed for key accessibility traits such as speech and other audio output, tactual nature of control buttons, and the quality of visual displays. It was also determined whether or not a blind or visually impaired person could independently complete tasks such as programming the IP for insulin delivery, replacing batteries, and reading manuals and other documentation. Results It was found that IPs have not improved in accessibility since 2004. None have speech output, and with the exception of the Animas IR 2020, no significantly improved visual display characteristics were found. Documentation is still not completely accessible. Conclusion Insulin pumps are relatively complex devices, with serious health consequences resulting from improper use. For IPs to be used safely and independently by blind and visually impaired patients, they must include voice output to communicate all the information presented on their display screens. Enhancing display contrast and the size of the displayed information would also improve accessibility for visually impaired users. The IPs must also come with accessible user documentation in alternate formats. PMID:20144301

Are current insulin pumps accessible to blind and visually impaired people?

PubMed

Burton, Darren M; Uslan, Mark M; Blubaugh, Morgan V; Clements, Charles W

2009-05-01

In 2004, Uslan and colleagues determined that insulin pumps (IPs) on the market were largely inaccessible to blind and visually impaired persons. The objective of this study is to determine if accessibility status changed in the ensuing 4 years. Five IPs on the market in 2008 were acquired and analyzed for key accessibility traits such as speech and other audio output, tactual nature of control buttons, and the quality of visual displays. It was also determined whether or not a blind or visually impaired person could independently complete tasks such as programming the IP for insulin delivery, replacing batteries, and reading manuals and other documentation. It was found that IPs have not improved in accessibility since 2004. None have speech output, and with the exception of the Animas IR 2020, no significantly improved visual display characteristics were found. Documentation is still not completely accessible. Insulin pumps are relatively complex devices, with serious health consequences resulting from improper use. For IPs to be used safely and independently by blind and visually impaired patients, they must include voice output to communicate all the information presented on their display screens. Enhancing display contrast and the size of the displayed information would also improve accessibility for visually impaired users. The IPs must also come with accessible user documentation in alternate formats. 2009 Diabetes Technology Society.

Diagnostic procedures for catheter malfunction in programmable implantable intraperitoneal insulin infusion devices.

PubMed

Olsen, C L; Turner, D S; Iravani, M; Waxman, K; Selam, J L; Charles, M A

1995-01-01

To evaluate the roles of 1) abdominal radiography, 2) a pressure diagnostic procedure (PDP) using a standardized diluent infusion into the catheter sideport, and 3) radiocontrast imaging of the catheter lumen as procedures for diagnosing catheter malfunction in diabetic patients implanted with a programmable intraperitoneal infusion device. Sixteen type I diabetic patients implanted with Infusaid programmable intraperitoneal insulin pumps were studied. The ability of the above three procedures to assist diagnosis of catheter malfunction and distinguish between occlusion and catheter breakage was retrospectively analyzed. Glycated hemoglobin was measured to determine the clinical importance of catheter malfunctions and decreases in pump flow due to insulin aggregation in the pump chamber. Mean glycated hemoglobin levels increased significantly from 8.0 +/- 0.3 to 9.0 +/- 0.4% (P < 0.05) before and after catheter malfunction, but not during pump flow slowdowns. Mean peak pressure during PDP was 1.96 +/- 0.14 psi (P < 0.01 vs. normal) in reversibly occluded catheters and 1.86 +/- 0.35 psi (P < 0.05 vs. normal) in broken catheters, compared with 1.32 +/- 0.23 psi in normal catheters. Decay times during PDP were > 50 s for both reversibly occluded and broken catheters (P < 0.001 vs. normal of 3.6 +/- 0.82 s). Abdominal radiographs and sideport injections of contrast material were used to distinguish the types of broken catheters. Catheter breakage and occlusion are complications in implantable insulin infusion systems and result in metabolic deterioration. The presence of a sideport allows pressure data and radiographic procedures to assist in determining the cause of catheter malfunction. A diagnostic algorithm was generated to improve efficiency in investigating catheter problems.

[Prevalence of Dental Caries in Type 1 Diabetic Patients Treated with Insulin Pump].

PubMed

Garcia, Rosana; Coelho, Ana; Paula, Anabela; Marques Ferreira, Manuel; Caramelo, Francisco; Barros, Luísa; Batista, Carla; Melo, Miguel; Silva, Mário Jorge; Carrilho, Eunice

2016-08-01

Type 1 diabetes mellitus and oral health are strictly related on a reciprocal basis, and an increased susceptibility to a wide variety of oral diseases is recognised in these patients. The aim of the present study was to establish a relationship between the prevalence of dental caries in Type 1 diabetic patients treated with insulin pump and that of non-diabetic patients. An observational clinical study of analytical and cross-sectional nature was conducted. The sample consisted of 30 adults with diabetes mellitus treated with insulin pump (selected from the Coimbra Hospital and Universitary Centre) and 30 nondiabetic adults (selected from the ones accompanying the diabetic patients). One dentist evaluated all of the patients between January and May of 2015 in the Faculty of Medicine of the University of Coimbra. During the clinical evaluation a case report form adapted to the objectives of the investigation was completed. Data analysis was performed and the significance level was set at 5%. Diabetic patients showed similar levels on the caries and plaque index to non-diabetic patients. There were no statistically significant differences between the two groups as regards oral hygiene habits and frequency of visits to the dentist. Discussão: Although diabetics' diet is less abundant in carbohydrates, which provides a smaller exposure to cariogenic food, the regularity of meals can increase the risk of caries since the critical pH for demineralization is reached frequently throughout the day. However, the existence of a chronic condition may determine a high concern for general preventive care, resulting in an overall improvement of their oral health, which could justify the results. Type 1 diabetic patients treated with insulin pump don't have a higher prevalence of dental caries.

Insulin pump treatment compared with multiple daily injections for treatment of type 2 diabetes (OpT2mise): a randomised open-label controlled trial.

PubMed

Reznik, Yves; Cohen, Ohad; Aronson, Ronnie; Conget, Ignacio; Runzis, Sarah; Castaneda, Javier; Lee, Scott W

2014-10-04

Many patients with advanced type 2 diabetes do not meet their glycated haemoglobin targets and randomised controlled studies comparing the efficacy of pump treatment and multiple daily injections for lowering glucose in insulin-treated patients have yielded inconclusive results. We aimed to resolve this uncertainty with a randomised controlled trial (OpT2mise). We did this multicentre, controlled trial at 36 hospitals, tertiary care centres, and referal centres in Canada, Europe, Israel, South Africa, and the USA. Patients with type 2 diabetes who had poor glycaemic control despite multiple daily injections with insulin analogues were enrolled into a 2-month dose-optimisation run-in period. After the run-in period, patients with glycated haemoglobin of 8·0-12·0% (64-108 mmol/mol) were randomly assigned (1:1) by a computer-generated randomisation sequence (block size 2 with probability 0·75 and size 4 with probability 0·25) to pump treatment or to continue with multiple daily injections. Neither patients nor investigators were masked to treatment allocation. The primary endpoint was change in mean glycated haemoglobin between baseline and end of the randomised phase for the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01182493. 495 of 590 screened patients entered the run-in phase and 331 were randomised (168 to pump treatment, 163 to multiple daily injections). Mean glycated haemoglobin at baseline was 9% (75 mmol/mol) in both groups. At 6 months, mean glycated haemoglobin had decreased by 1·1% (SD 1·2; 12 mmol/mol, SD 13) in the pump treatment group and 0·4% (SD 1·1; 4 mmol/mol, SD 12) in the multiple daily injection group, resulting in a between-group treatment difference of -0·7% (95% CI -0·9 to -0·4; -8 mmol/mol, 95% CI -10 to -4, p<0·0001). At the end of the study, the mean total daily insulin dose was 97 units (SD 56) with pump treatment versus 122 units (SD 68) for multiple daily injections (p<0·0001), with no significant difference in bodyweight change between the two groups (1·5 kg [SD 3·5] vs 1·1 kg [3·6], p=0·322). Two diabetes-related serious adverse events (hyperglycaemia or ketosis without acidosis) resulting in hospital admission occurred in the pump treatment group compared with one in the multiple daily injection group. No ketoacidosis occurred in either group and one episode of severe hypoglycaemia occurred in the multiple daily injection group. In patients with poorly controlled type 2 diabetes despite using multiple daily injections of insulin, pump treatment can be considered as a safe and valuable treatment option. Medtronic. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparative effectiveness and safety of methods of insulin delivery and glucose monitoring for diabetes mellitus: a systematic review and meta-analysis.

PubMed

Yeh, Hsin-Chieh; Brown, Todd T; Maruthur, Nisa; Ranasinghe, Padmini; Berger, Zackary; Suh, Yong D; Wilson, Lisa M; Haberl, Elisabeth B; Brick, Jessica; Bass, Eric B; Golden, Sherita Hill

2012-09-04

Patients with diabetes mellitus need information about the effectiveness of innovations in insulin delivery and glucose monitoring. To review how intensive insulin therapy (multiple daily injections [MDI] vs. rapid-acting analogue-based continuous subcutaneous insulin infusion [CSII]) or method of monitoring (self-monitoring of blood glucose [SMBG] vs. real-time continuous glucose monitoring [rt-CGM]) affects outcomes in types 1 and 2 diabetes mellitus. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials through February 2012 without language restrictions. 33 randomized, controlled trials in children or adults that compared CSII with MDI (n=19), rt-CGM with SMBG (n=10), or sensor-augmented insulin pump use with MDI and SMBG (n=4). 2 reviewers independently evaluated studies for eligibility and quality and serially abstracted data. In randomized, controlled trials, MDI and CSII showed similar effects on hemoglobin A1c (HbA1c) levels and severe hypoglycemia in children or adults with type 1 diabetes mellitus and adults with type 2 diabetes mellitus. In adults with type 1 diabetes mellitus, HbA1c levels decreased more with CSII than with MDI, but 1 study heavily influenced these results. Compared with SMBG, rt-CGM achieved a lower HbA1c level (between-group difference of change, 0.26% [95% CI, 0.33% to 0.19%]) without any difference in severe hypoglycemia. Sensor-augmented insulin pump use decreased HbA1c levels more than MDI and SMBG did in persons with type 1 diabetes mellitus (between-group difference of change, 0.68% [CI, 0.81% to 0.54%]). Little evidence was available on other outcomes. Many studies were small, of short duration, and limited to white persons with type 1 diabetes mellitus. Continuous subcutaneous insulin infusion and MDI have similar effects on glycemic control and hypoglycemia, except CSII has a favorable effect on glycemic control in adults with type 1 diabetes mellitus. For glycemic control, rt-CGM is superior to SMBG and sensor-augmented insulin pumps are superior to MDI and SMBG without increasing the risk for hypoglycemia. Agency for Healthcare Research and Quality.

Automatic Adaptation of Basal Insulin Using Sensor-Augmented Pump Therapy.

PubMed

Herrero, Pau; Bondia, Jorge; Giménez, Marga; Oliver, Nick; Georgiou, Pantelis

2018-03-01

People with insulin-dependent diabetes rely on an intensified insulin regimen. Despite several guidelines, they are usually impractical and fall short in achieving optimal glycemic outcomes. In this work, a novel technique for automatic adaptation of the basal insulin profile of people with diabetes on sensor-augmented pump therapy is presented. The presented technique is based on a run-to-run control law that overcomes some of the limitations of previously proposed methods. To prove its validity, an in silico validation was performed. Finally, the artificial intelligence technique of case-based reasoning is proposed as a potential solution to deal with variability in basal insulin requirements. Over a period of 4 months, the proposed run-to-run control law successfully adapts the basal insulin profile of a virtual population (10 adults, 10 adolescents, and 10 children). In particular, average percentage time in target [70, 180] mg/dl was significantly improved over the evaluated period (first week versus last week): 70.9 ± 11.8 versus 91.1 ± 4.4 (adults), 46.5 ± 11.9 versus 80.1 ± 10.9 (adolescents), 49.4 ± 12.9 versus 73.7 ± 4.1 (children). Average percentage time in hypoglycemia (<70 mg/dl) was also significantly reduced: 9.7 ± 6.6 versus 0.9 ± 1.2 (adults), 10.5 ± 8.3 versus 0.83 ± 1.0 (adolescents), 10.9 ± 6.1 versus 3.2 ± 3.5 (children). When compared against an existing technique over the whole evaluated period, the presented approach achieved superior results on percentage of time in hypoglycemia: 3.9 ± 2.6 versus 2.6 ± 2.2 (adults), 2.9 ± 1.9 versus 2.0 ± 1.5 (adolescents), 4.6 ± 2.8 versus 3.5 ± 2.0 (children), without increasing the percentage time in hyperglycemia. The present study shows the potential of a novel technique to effectively adjust the basal insulin profile of a type 1 diabetes population on sensor-augmented insulin pump therapy.

Tolerogenic insulin peptide therapy precipitates type 1 diabetes.

PubMed

Bergman, Marie-Louise; Lopes-Carvalho, Thiago; Martins, Ana-Catarina; Grieco, Fabio A; Eizirik, Décio L; Demengeot, Jocelyne

2017-07-03

Daniel et al. (https://doi.org/10.1084/jem.20110574) have previously published in JEM a study on the preventive effect of tolerogenic vaccination with a strong agonist insulin mimetope in type 1 diabetes. Our study now challenges these results and shows that osmotic pump delivery of the modified insulin peptide R22E did not prevent hyperglycemia, accelerated disease onset, increased its incidence, and worsened insulitis. © 2017 Bergman et al.

A qualitative comparison of needles and insulin pump use in children with type 1 diabetes.

PubMed

Ferrari, Madeleine; McIlwain, Doris Jf; Ambler, Geoffrey

2016-06-01

Managing type 1 diabetes mellitus is an ongoing and challenging process; we investigated children's experience of different treatment regimens. Interviews with 17 children (7-15 years) at two time points were analysed using the grounded theory approach. Illness phase and treatment regimen shaped how bodily cues were interpreted. Insulin pump therapy allowed children to listen to and trust their bodily cues rather than override. Shame was a barrier to support engagement. Different internalised and externalised views of type 1 diabetes mellitus emerged. Overall, children were insightful experts of their own experiences. Recommendations for psychological interventions would benefit from empirical testing.

Insulin delivery route for the artificial pancreas: subcutaneous, intraperitoneal, or intravenous? Pros and cons.

PubMed

Renard, Eric

2008-07-01

Insulin delivery is a crucial component of a closed-loop system aiming at the development of an artificial pancreas. The intravenous route, which has been used in the bedside artificial pancreas model for 30 years, has clear advantages in terms of pharmacokinetics and pharmacodynamics, but cannot be used in any ambulatory system so far. Subcutaneous (SC) insulin infusion benefits from the broad expansion of insulin pump therapy that promoted the availability of constantly improving technology and fast-acting insulin analog use. However, persistent delays of insulin absorption and action, variability and shortterm stability of insulin infusion from SC-inserted catheters generate effectiveness and safety issues in view of an ambulatory, automated, glucose-controlled, artificial beta cell. Intraperitoneal insulin delivery, although still marginally used in diabetes care, may offer an interesting alternative because of its more-physiological plasma insulin profiles and sustained stability and reliability of insulin delivery.

Insulin pumps and continuous glucose monitoring (CGM) in preschool and school-age children: how schools can integrate technology.

PubMed

Bratina, Natasa; Battelino, Tadej

2010-08-01

The use of insulin pump and continuous glucose monitoring (CGM) therapies in children and adolescents with type 1 diabetes (T1DM) has increased over the last 10 years, including the group of children <7 years of age. When these young children use pumps and CGM, their families, teachers, school nurses and professional caregivers (who take the place of school nurses in many countries) in preschools, kindergartens and primary schools need to give them special attention since they depend completely on their help in succeeding with diabetes management. Written individualized diabetesrelated health-care plans should be agreed upon between parents, school nurses, professional caregivers and teachers, and the diabetes healthcare team. A structured educational program should be provided for preschools, kindergartens and primary schools that includes information about and practical training for the use of these new diabetes-related technologies.

Interventions That Restore Awareness of Hypoglycemia in Adults With Type 1 Diabetes: A Systematic Review and Meta-analysis.

PubMed

Yeoh, Ester; Choudhary, Pratik; Nwokolo, Munachiso; Ayis, Salma; Amiel, Stephanie A

2015-08-01

Impaired awareness of hypoglycemia (IAH) increases the risk of severe hypoglycemia (SH) sixfold and affects 30% of adults with type 1 diabetes (T1D). This systematic review and meta-analysis looks at the educational, technological, and pharmacological interventions aimed at restoring hypoglycemia awareness (HA) in adults with T1D. We searched The Cochrane Library, MEDLINE, Embase, Science Citation Index Expanded, Social Sciences Citation Index, PsycINFO, and CINAHL from inception until 1 October 2014. Included studies described HA status at baseline. Outcome measures were SH rates, change in HA, counterregulatory hormone responses, and glycemic control. Forty-three studies (18 randomized controlled trials, 25 before-and-after studies) met the inclusion criteria, comprising 27 educational, 11 technological, and 5 pharmacological interventions. Educational interventions included structured diabetes education on flexible insulin therapy, including psychotherapeutic and behavioral techniques. These were able to reduce SH and improve glycemic control, with greater benefit from the latter two techniques in improving IAH. Technological interventions (insulin pump therapy, continuous glucose monitoring, and sensor-augmented pump) reduced SH, improved glycemic control, and restored awareness when used in combination with structured education and frequent contact. Pharmacological studies included four insulin studies and one noninsulin study, but with low background SH prevalence rates. This review provides evidence for the effectiveness of a stepped-care approach in the management of patients with IAH, initially with structured diabetes education in flexible insulin therapy, which may incorporate psychotherapeutic and behavioral therapies, progressing to diabetes technology, incorporating sensors and insulin pumps, in those with persisting need. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

SMARTDIAB: a communication and information technology approach for the intelligent monitoring, management and follow-up of type 1 diabetes patients.

PubMed

Mougiakakou, Stavroula G; Bartsocas, Christos S; Bozas, Evangelos; Chaniotakis, Nikos; Iliopoulou, Dimitra; Kouris, Ioannis; Pavlopoulos, Sotiris; Prountzou, Aikaterini; Skevofilakas, Marios; Tsoukalis, Alexandre; Varotsis, Kostas; Vazeou, Andrianni; Zarkogianni, Konstantia; Nikita, Konstantina S

2010-05-01

SMARTDIAB is a platform designed to support the monitoring, management, and treatment of patients with type 1 diabetes mellitus (T1DM), by combining state-of-the-art approaches in the fields of database (DB) technologies, communications, simulation algorithms, and data mining. SMARTDIAB consists mainly of two units: 1) the patient unit (PU); and 2) the patient management unit (PMU), which communicate with each other for data exchange. The PMU can be accessed by the PU through the internet using devices, such as PCs/laptops with direct internet access or mobile phones via a Wi-Fi/General Packet Radio Service access network. The PU consists of an insulin pump for subcutaneous insulin infusion to the patient and a continuous glucose measurement system. The aforementioned devices running a user-friendly application gather patient's related information and transmit it to the PMU. The PMU consists of a diabetes data management system (DDMS), a decision support system (DSS) that provides risk assessment for long-term diabetes complications, and an insulin infusion advisory system (IIAS), which reside on a Web server. The DDMS can be accessed from both medical personnel and patients, with appropriate security access rights and front-end interfaces. The DDMS, apart from being used for data storage/retrieval, provides also advanced tools for the intelligent processing of the patient's data, supporting the physician in decision making, regarding the patient's treatment. The IIAS is used to close the loop between the insulin pump and the continuous glucose monitoring system, by providing the pump with the appropriate insulin infusion rate in order to keep the patient's glucose levels within predefined limits. The pilot version of the SMARTDIAB has already been implemented, while the platform's evaluation in clinical environment is being in progress.

Lessons Learned From a Pilot RCT of Simultaneous Versus Delayed Initiation of Continuous Glucose Monitoring in Children and Adolescents With Type 1 Diabetes Starting Insulin Pump Therapy

PubMed Central

Olivier, Patricia; Huot, Celine; Richardson, Christine; Nakhla, Meranda; Romain, Judette

2014-01-01

Uncertainty remains about effectiveness of continuous glucose monitoring (CGM) in pediatric type 1 diabetes (T1D). Success with CGM is related to CGM adherence, which may relate to readiness to make the behavior changes required for effective use. We hypothesize that readiness for change will be greater at initiation of insulin pump therapy than in established pump users, and that this will predict CGM adherence. Our objective was to evaluate the feasibility of a randomized controlled trial (RCT) in children with established T1D comparing simultaneous pump and CGM initiation to standard pump therapy with delayed CGM initiation. We randomized participants to simultaneous pump and CGM initiation or to standard pump therapy with the option of adding CGM 4 months later. CGM adherence was tracked via web-based download and readiness for change assessed with the SOCRATES questionnaire. Of 41 eligible children, 20 agreed to participate; 15 subjects completed the study (7 males; baseline age 11.8 ± 4.0 years; T1D duration 2.7 ± 2.7 years; mean A1C 8.2 ± 0.8%). Six of 8 simultaneous group subjects used CGM > 60% of the time for 4 months compared to 1 of 7 delayed group subjects (P = .02). Using SOCRATES, we could assign 87-100% of subjects to a single motivation stage at baseline and 4 months. This pilot study demonstrates the feasibility of randomizing pump naïve children and adolescents with established T1D to simultaneous pump and CGM initiation versus standard pump therapy with delayed CGM initiation. Lessons from this pilot study were used to inform development of a full-scale multicenter RCT. PMID:24876616

Do youth with type 1 diabetes exercise safely? A focus on patient practices and glycemic outcomes.

PubMed

Roberts, Alissa J; Yi-Frazier, Joyce P; Aitken, Karen E; Mitrovich, Connor A; Pascual, Michael F; Taplin, Craig E

2017-08-01

Insulin adjustments have been shown to reduce glycemic excursions during and after exercise, but little is known about their use in youth with type 1 diabetes (T1D). We aimed to assess practices in youth with T1D around exercise, assess factors that influence practices, and examine associations between key behaviors and glycemic outcomes. We developed the 'Type 1 Diabetes Report of Exercise Practices Survey (T1D-REPS)' and piloted this tool in 100 youth with T1D on an insulin pump. Participants completed a 3-day physical activity recall and 30 days of pump/glucose data were collected. Chart review was conducted for key clinical measures. Eighty-four percent of participants modified their insulin regimen around exercise; only 40% reported adjusting prandial insulin immediately before exercise while 68% reported some modification (suspension or decrease) of basal insulin during exercise. Following exercise, only 10% reported reducing overnight basal insulin. Those who performed ≥ 5 glucose checks/day adjusted basal insulin during exercise more frequently than those with fewer daily glucose checks (33% vs. 13%, p = 0.05, chi-squared = 3.7), and were more likely to report decreasing insulin dose for the bedtime snack following exercise (50% vs. 17%, p = 0.004, chi-squared = 8.2). Despite several studies showing the frequency of hypoglycemia during and after exercise, many youth are not adjusting insulin for exercise. A tool designed to capture patient practices and provide clinicians with a framework for patient education may lead to improved safety around exercise in youth with T1D. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY 2018 POSITION STATEMENT ON INTEGRATION OF INSULIN PUMPS AND CONTINUOUS GLUCOSE MONITORING IN PATIENTS WITH DIABETES MELLITUS.

PubMed

Grunberger, George; Handelsman, Yehuda; Bloomgarden, Zachary T; Fonseca, Vivian A; Garber, Alan J; Haas, Richard A; Roberts, Victor L; Umpierrez, Guillermo E

2018-03-01

This document represents the official position of the American Association of Clinical Endocrinologists and American College of Endocrinology. Where there are no randomized controlled trials or specific U.S. FDA labeling for issues in clinical practice, the participating clinical experts utilized their judgment and experience. Every effort was made to achieve consensus among the committee members. Position statements are meant to provide guidance, but they are not to be considered prescriptive for any individual patient and cannot replace the judgment of a clinician. AACE/ACE Task Force on Integration of Insulin Pumps and Continuous Glucose Monitoring in the Management of Patients With Diabetes Mellitus Chair George Grunberger, MD, FACP, FACE Task Force Members Yehuda Handelsman, MD, FACP, FNLA, MACE Zachary T. Bloomgarden, MD, MACE Vivian A. Fonseca, MD, FACE Alan J. Garber, MD, PhD, FACE Richard A. Haas, MD, FACE Victor L. Roberts, MD, MBA, FACP, FACE Guillermo E. Umpierrez, MD, CDE, FACP, FACE Abbreviations: AACE = American Association of Clinical Endocrinologists ACE = American College of Endocrinology A1C = glycated hemoglobin BGM = blood glucose monitoring CGM = continuous glucose monitoring CSII = continuous subcutaneous insulin infusion DM = diabetes mellitus FDA = Food & Drug Administration MDI = multiple daily injections T1DM = type 1 diabetes mellitus T2DM = type 2 diabetes mellitus SAP = sensor-augmented pump SMBG = self-monitoring of blood glucose STAR 3 = Sensor-Augmented Pump Therapy for A1C Reduction phase 3 trial.

Runtime Verification of Pacemaker Functionality Using Hierarchical Fuzzy Colored Petri-nets.

PubMed

Majma, Negar; Babamir, Seyed Morteza; Monadjemi, Amirhassan

2017-02-01

Today, implanted medical devices are increasingly used for many patients and in case of diverse health problems. However, several runtime problems and errors are reported by the relevant organizations, even resulting in patient death. One of those devices is the pacemaker. The pacemaker is a device helping the patient to regulate the heartbeat by connecting to the cardiac vessels. This device is directed by its software, so any failure in this software causes a serious malfunction. Therefore, this study aims to a better way to monitor the device's software behavior to decrease the failure risk. Accordingly, we supervise the runtime function and status of the software. The software verification means examining limitations and needs of the system users by the system running software. In this paper, a method to verify the pacemaker software, based on the fuzzy function of the device, is presented. So, the function limitations of the device are identified and presented as fuzzy rules and then the device is verified based on the hierarchical Fuzzy Colored Petri-net (FCPN), which is formed considering the software limits. Regarding the experiences of using: 1) Fuzzy Petri-nets (FPN) to verify insulin pumps, 2) Colored Petri-nets (CPN) to verify the pacemaker and 3) To verify the pacemaker by a software agent with Petri-network based knowledge, which we gained during the previous studies, the runtime behavior of the pacemaker software is examined by HFCPN, in this paper. This is considered a developing step compared to the earlier work. HFCPN in this paper, compared to the FPN and CPN used in our previous studies reduces the complexity. By presenting the Petri-net (PN) in a hierarchical form, the verification runtime, decreased as 90.61% compared to the verification runtime in the earlier work. Since we need an inference engine in the runtime verification, we used the HFCPN to enhance the performance of the inference engine.

Diabetic management in high risk patients (pregnancy, insulin pumps).

PubMed

Vanhaverbeke, G; Mertens, A; Mathieu, C

2004-01-01

During the past decades our understanding about the clinical impact of diabetes has changed. We now know for certain that a good (read : near normal) glycemic control is necessary to prevent chronic complications of this disease in women regardless of the type of diabetes. Pregnancy is a specific situation whereby a "near normal" control is wanted not only for the patient but also for the fetus. Several studies have shown a correlation beween glycemic control and complications of pregnancy. Reaching optimal glycemic control is mandatory even before the pregnancy starts, considering the time window of occurance of the severe foetal congenital malformations (first weeks of pregnancy). The role of pre-conception care is emphasized. Optimal control in type 1 and type 2 diabetic patients can best be reached through intensive insulin therapy, but reaching normoglycemia is mainly limited by the occurence of hypoglycemia. The introduction of the new insulin analogues is an important step in our arsenal to achieve control using multiple daily insulin injections, but Novorapid and Lantus have not yet been approved for use in pregnancy. Insulin pumps are often used in pregnant patients, allowing an even better glycemic control with less hypoglycemia. An absolute requirement for CSII therapy to be successful is patient education and motivation by an experienced team.

Nonaqueous, mini-dose glucagon for treatment of mild hypoglycemia in adults with type 1 diabetes: A dose-seeking study

USDA-ARS?s Scientific Manuscript database

To evaluate mini-dose glucagon in adults with type 1 diabetes using a stable, liquid, ready-to-use preparation, twelve adults with type 1 diabetes receiving treatment with insulin pumps received subcutaneous doses of 75, 150, and 300 ug of nonaqueous glucagon. Plasma glucose, glucagon, and insulin c...

AZ-101 Mixer Pump Demonstration Data Acquisition System and Gamma Cart Data Acquisition Control System Software Configuration Management Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

WHITE, D.A.

1999-12-29

This Software Configuration Management Plan (SCMP) provides the instructions for change control of the AZ1101 Mixer Pump Demonstration Data Acquisition System (DAS) and the Sludge Mobilization Cart (Gamma Cart) Data Acquisition and Control System (DACS).

The role of insulin glulisine to improve glycemic control in children with diabetes mellitus.

PubMed

Lih, Anna; Hibbert, Emily; Wong, Tang; Girgis, Christian M; Garg, Nidhi; Carter, John N

2010-11-26

Glulisine (Apidra(®)) is a rapid-acting human insulin analog approved for use in children with diabetes mellitus ≥4 years of age. Management of children with type 1 diabetes has seen a shift in favor of mimicking normal physiological insulin responses with multiple daily injections or continuous subcutaneous insulin infusions (CSII). Few studies have compared the rapid-acting insulin analogs in this population but limited data indicate that glulisine is as effective as lispro when used in a basal-bolus regimen. This review appraises the current available studies and reviews on insulin glulisine in children. An extensive keyword search of 'insulin glulisine', 'insulin analogs', and 'Apidra' in the pediatric population was performed. These studies have suggested that glulisine is safe, well tolerated, and is an effective option in the diabetes armamentarium. Further studies are needed to determine its safety for use in CSII pumps in the pediatric population.

The effect of balance holes to centrifugal pump performance

NASA Astrophysics Data System (ADS)

Babayigit, O.; Ozgoren, M.; Aksoy, M. H.; Kocaaslan, O.

2017-07-01

The aim of this study is to analyze of a centrifugal pump with and without balance holes by using ANSYS-Fluent software. The pump used in the study is a commercial centrifugal pump consisting of two stages that is a model of Sempa Pump Company. Firstly, models of impeller, diffuser, suction and discharge sections of the centrifugal pump were separately drawn using Ansys and Solidworks software. Later, grid structures were generated on the flow volume of the pump. Turbulent flow volume was numerically solved by realizable k-є turbulence model. The flow analyses were focused on the centrifugal pump performance and the flow characteristics under different operational conditions with/without balance holes. Distributions of flow characteristics such as velocity and pressure distributions in the flow volume were also determined, numerically. The results of Computational Fluid Dynamics (CFD) with/without balance holes for the pump head and hydraulic efficiency on the design flow rate of 80 m3/h were found to be 81.5/91.3 m and 51.9/65.3%, respectively.

Neutral insulin solutions physically stabilized by addition of Zn2+.

PubMed

Brange, J; Havelund, S; Hommel, E; Sørensen, E; Kühl, C

1986-01-01

Commercial neutral insulin solutions, all of which contain 2-3 zinc atoms per hexameric unit of insulin, have a relatively limited physical stability when exposed to heat and movement, as for example in insulin infusion pumps. Physical stabilization of neutral insulin solutions has been obtained by addition of two extra Zn2+ per hexamer of insulin. This addition stabilizes porcine and human neutral solutions equally well and does not affect the chemical stability of the insulin. The stabilization is probably obtained by a further strengthening of the hexameric structure of insulin, so that the formation of insoluble insulin fibrils (via the dissociation into the insulin monomer or dimer) is impeded or prevented. The addition of an extra 2 Zn2+ has been shown to be without influence on the insulin immunogenicity in rabbits or on the rate of absorption after subcutaneous injection in diabetic patients. It is concluded that neutral insulin solution can be physically stabilized by addition of extra Zn2+ without affecting other qualities of the insulin preparation including chemical stability, immunogenicity, and duration of action after injection.

A Review of Artificial Pancreas Technologies with an Emphasis on Bi-hormonal Therapy

PubMed Central

Bakhtiani, Parkash A.; Zhao, Lauren M.; Youssef, Joseph El; Castle, Jessica R.; Ward, W. Kenneth

2013-01-01

Since the discovery of insulin, great progress has been made to improve the accuracy and safety of automated insulin delivery systems to help patients with type 1 diabetes achieve their treatment goals without causing hypoglycemia. In recent years, bioengineering technology has greatly advanced diabetes management, with the development of blood glucose meters, continuous glucose monitors, insulin pumps, and control systems for automatic delivery of one or more hormones. New insulin analogues have improved subcutaneous absorption characteristics, but do not completely eliminate the risk of hypoglycemia. Insulin effect is counteracted by glucagon in non-diabetic individuals, while glucagon secretion in those with type 1 diabetes is impaired. The use of glucagon in the artificial pancreas is therefore a logical and feasible option for preventing and treating hypoglycemia. However, commercially available glucagon is not stable in aqueous solution for long periods, forming potentially cytotoxic fibrils that aggregate quickly. Therefore, a more stable formulation of glucagon is needed for long-term use and storage in a bi-hormonal pump. Additionally, a model of glucagon action in type 1 diabetes is lacking, further limiting the inclusion of glucagon into systems employing model-assisted control. As a result, although several investigators have been working to help develop bi-hormonal systems for patients with type 1 diabetes, most continue to utilize single hormone systems employing only insulin. This article seeks to focus on the attributes of glucagon and its use in bi-hormonal systems. PMID:23602044

Role of continuous subcutaneous insulin infusion in patients with recalcitrant diabetes in South India.

PubMed

Sudhakaran, Chidambarann; Anjana, Ranjit Mohan; Rao, Kavitha; Unnikrishnan, Ranjit; Suresh, Thangamani; Mohan, Viswanathan

2009-11-01

We aimed to assess the effect of continuous subcutaneous insulin infusion (CSII) therapy in patients with "recalcitrant diabetes" whose glycemia had not been controlled adequately with multiple daily injections of insulin or insulin plus oral hypoglycemic agents. We retrospectively analyzed the medical records of patients with diabetes who were initiated on insulin pump therapy at our center in India between 2002 and 2007. Data analysis included fasting and postprandial blood glucose and glycated hemoglobin (HbA1c) values, insulin requirement, body weight, and the occurrence of hypoglycemia and diabetic ketoacidosis. We studied 33 patients with diabetes (type 1 [n = 17] and type 2 [n = 16]) who were on CSII therapy for a mean duration of 3.4 years. A statistically significant reduction in HbA1c was found after initiating CSII (prepump 10.7% vs. postpump 8.3%, P < 0.001). The reduction was greater in type 1 patients (10.6 +/- 2.1 vs. 8.0 +/- 1.6%) than in type 2 patients (11.0 +/- 2.1 vs. 8.8 +/- 1.4%). There was a reduction in frequency of severe hypoglycemia after starting the CSII pump, and there were no instances of diabetic ketoacidosis. Although HbA1c levels did not reach optimal targets, our data indicate that CSII is an effective therapy for patients with diabetes having recalcitrant diabetes who can afford this treatment and whose glycemia is poorly controlled with conventional therapies.

Insulin pump patient characteristics and glucose control in the hospitalized setting.

PubMed

Kannan, Subramanian; Satra, Ankita; Calogeras, Ellen; Lock, Patricia; Lansang, M Cecilia

2014-05-01

Patients' knowledge of their insulin pumps and glucose control during hospitalization has not been studied. The aim was to study the determinants of glycemic control in patients using continuous subcutaneous insulin infusion (CSII) in the hospital. Three groups of patients were identified: those who did not need any inpatient education and continued on CSII (gorup A), those who received education then continued on CSII (group B), and those for whom CSII was not appropriate and were treated with multiple daily insulin injections (gorup C). We compared the measures of glycemic control between the 3 groups and analyzed which variables impacted glucose control. There were 50 patients, with 51 hospital admissions, 57% males, mean age 48 ± 13 years, 86% had type 1 diabetes (T1DM). The mean DM duration was 26 ± 14 years, mean duration of CSII use was 8.7 ± 6 years, and mean HbA1c was 7.6 ± 1.4%. The mean duration of hospital stay was 5.6 ± 4.6 days. Mean blood glucose (BG) and frequency of hyperglycemia and hypoglycemic events among the 3 groups adjusted for their duration of hospital stay were not statistically different. None of the patients developed diabetic ketoacidosis while using their pump. Stepwise multivariate analysis revealed knowledge of hypoglycemia correction was the single most important predictor of mean BG (P < .001). Patients who received inpatient education performed similarly to patients who did not need inpatient education. Patients who receive inpatient education on CSII fare similar as patients who did not require inpatient education. © 2014 Diabetes Technology Society.

ASPIRE In-Home: rationale, design, and methods of a study to evaluate the safety and efficacy of automatic insulin suspension for nocturnal hypoglycemia.

PubMed

Klonoff, David C; Bergenstal, Richard M; Garg, Satish K; Bode, Bruce W; Meredith, Melissa; Slover, Robert H; Ahmann, Andrew; Welsh, John B; Lee, Scott W

2013-07-01

Nocturnal hypoglycemia is a barrier to therapy intensification efforts in diabetes. The Paradigm® Veo™ system may mitigate nocturnal hypoglycemia by automatically suspending insulin when a prespecified sensor glucose threshold is reached. ASPIRE (Automation to Simulate Pancreatic Insulin REsponse) In-Home (NCT01497938) was a multicenter, randomized, parallel, adaptive study of subjects with type 1 diabetes. The control arm used sensor-augmented pump therapy. The treatment arm used sensor-augmented pump therapy with threshold suspend, which automatically suspends the insulin pump in response to a sensor glucose value at or below a prespecified threshold. To be randomized, subjects had to have demonstrated ≥2 episodes of nocturnal hypoglycemia, defined as >20 consecutive minutes of sensor glucose values ≤65 mg/dl starting between 10:00 PM and 8:00 AM in the 2-week run-in phase. The 3-month study phase evaluated safety by comparing changes in glycated hemoglobin (A1C) values and evaluated efficacy by comparing the mean area under the glucose concentration time curves for nocturnal hypoglycemia events in the two groups. Other outcomes included the rate of nocturnal hypoglycemia events and the distribution of sensor glucose values. Data from the ASPIRE In-Home study should provide evidence on the safety of the threshold suspend feature with respect to A1C and its efficacy with respect to severity and duration of nocturnal hypoglycemia when used at home over a 3-month period. © 2013 Diabetes Technology Society.

Current topics in glycemic control by wearable artificial pancreas or bedside artificial pancreas with closed-loop system.

PubMed

Hanazaki, Kazuhiro; Munekage, Masaya; Kitagawa, Hiroyuki; Yatabe, Tomoaki; Munekage, Eri; Shiga, Mai; Maeda, Hiromichi; Namikawa, Tsutomu

2016-09-01

The incidence of diabetes is increasing at an unprecedented pace and has become a serious health concern worldwide during the last two decades. Despite this, adequate glycemic control using an artificial pancreas has not been established, although the 21st century has seen rapid developments in this area. Herein, we review current topics in glycemic control for both the wearable artificial pancreas for type 1 and type 2 diabetic patients and the bedside artificial pancreas for surgical diabetic patients. In type 1 diabetic patients, nocturnal hypoglycemia associated with insulin therapy remains a serious problem that could be addressed by the recent development of a wearable artificial pancreas. This smart phone-like device, comprising a real-time, continuous glucose monitoring system and insulin pump system, could potentially significantly reduce nocturnal hypoglycemia compared with conventional glycemic control. Of particular interest in this space are the recent inventions of a low-glucose suspend feature in the portable systems that automatically stops insulin delivery 2 h following a glucose sensor value <70 mg/dL and a bio-hormonal pump system consisting of insulin and glucagon pumps. Perioperative tight glycemic control using a bedside artificial pancreas with the closed-loop system has also proved safe and effective for not only avoiding hypoglycemia, but also for reducing blood glucose level variability resulting in good surgical outcomes. We hope that a more sophisticated artificial pancreas with closed-loop system will now be taken up for routine use worldwide, providing enormous relief for patients suffering from uncontrolled hyperglycemia, hypoglycemia, and/or variability in blood glucose concentrations.

[Technological innovations in the treatment of type 1 diabetes in pediatrics].

PubMed

Tubiana-Rufi, Nadia

2016-01-01

Insulin pumps, continuous glucose monitoring sensors and algorithms for managing the doses of insulin necessary to control blood sugar levels within target values: more and more research is being carried out into "closed loop" systems. The artificial pancreas is today at the stage of clinical trials in adults and children. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Josh A. Salmond

2009-08-07

The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and lowmore » residual stresses. The products fabricated are used on multiple programs.« less

Vibration analysis of large centrifugal pump rotors

NASA Astrophysics Data System (ADS)

Y Zhao, W.; Ge, J. G.; Ma, D.; Li, C. M.; Bao, S. B.

2013-12-01

Through the critical speed of centrifugal pumps, internal flow field and the force of the impeller, we analyze centrifugal pump vibration. Using finite element analysis software ANSYS to calculate the natural frequency of the rotor system and the critical speed; with the help of the Fluent software to simulate pump internal flow field, we conclude that speed increase will not cause intense vibration of the fluid in the pump. Using unsteady numerical simulation we discovered that in an impeller suffering transient radial force cyclical change periodically, as well as the frequency size determined by the product of the impeller speed and number of blades, resonance phenomena should make impeller to transient radial force frequency. If wanting to avoid pump resonance when it is running away, the transient radial force frequency should avoid the frequency range which can cause resonance.

Insulin administration: present strategies and future directions for a noninvasive (possibly more physiological) delivery

PubMed Central

Matteucci, Elena; Giampietro, Ottavio; Covolan, Vera; Giustarini, Daniela; Fanti, Paolo; Rossi, Ranieri

2015-01-01

Insulin is a life-saving medication for people with type 1 diabetes, but traditional insulin replacement therapy is based on multiple daily subcutaneous injections or continuous subcutaneous pump-regulated infusion. Nonphysiologic delivery of subcutaneous insulin implies a rapid and sustained increase in systemic insulin levels due to the loss of concentration gradient between portal and systemic circulations. In fact, the liver degrades about half of the endogenous insulin secreted by the pancreas into the venous portal system. The reverse insulin distribution has short- and long-term effects on glucose metabolism. Thus, researchers have explored less-invasive administration routes based on innovative pharmaceutical formulations, which preserve hormone stability and ensure the therapeutic effectiveness. This review examines some of the recent proposals from clinical and material chemistry point of view, giving particular attention to patients’ (and diabetologists’) ideal requirements that organic chemistry could meet. PMID:26124635

Day-and-night glycaemic control with closed-loop insulin delivery versus conventional insulin pump therapy in free-living adults with well controlled type 1 diabetes: an open-label, randomised, crossover study.

PubMed

Bally, Lia; Thabit, Hood; Kojzar, Harald; Mader, Julia K; Qerimi-Hyseni, Jehona; Hartnell, Sara; Tauschmann, Martin; Allen, Janet M; Wilinska, Malgorzata E; Pieber, Thomas R; Evans, Mark L; Hovorka, Roman

2017-04-01

Tight control of blood glucose concentration in people with type 1 diabetes predisposes to hypoglycaemia. We aimed to investigate whether day-and-night hybrid closed-loop insulin delivery can improve glucose control while alleviating the risk of hypoglycaemia in adults with HbA 1c below 7·5% (58 mmol/mol). In this open-label, randomised, crossover study, we recruited adults (aged ≥18 years) with type 1 diabetes and HbA 1c below 7·5% from Addenbrooke's Hospital (Cambridge, UK) and Medical University of Graz (Graz, Austria). After a 2-4 week run-in period, participants were randomly assigned (1:1), using web-based randomly permuted blocks of four, to receive insulin via the day-and-night hybrid closed-loop system or usual pump therapy for 4 weeks, followed by a 2-4 week washout period and then the other intervention for 4 weeks. Treatment interventions were unsupervised and done under free-living conditions. During the closed-loop period, a model-predictive control algorithm directed insulin delivery, and prandial insulin delivery was calculated with a standard bolus wizard. The primary outcome was the proportion of time when sensor glucose concentration was in target range (3·9-10·0 mmol/L) over the 4 week study period. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT02727231, and is completed. Between March 21 and June 24, 2016, we recruited 31 participants, of whom 29 were randomised. One participant withdrew during the first closed-loop period because of dissatisfaction with study devices and glucose control. The proportion of time when sensor glucose concentration was in target range was 10·5 percentage points higher (95% CI 7·6-13·4; p<0·0001) during closed-loop delivery compared with usual pump therapy (65·6% [SD 8·1] when participants used usual pump therapy vs 76·2% [6·4] when they used closed-loop). Compared with usual pump therapy, closed-loop delivery also reduced the proportion of time spent in hypoglycaemia: the proportion of time with glucose concentration below 3·5 mmol/L was reduced by 65% (53-74, p<0·0001) and below 2·8 mmol/L by 76% (59-86, p<0·0001). No episodes of serious hypoglycaemia or other serious adverse events occurred. Use of day-and-night hybrid closed-loop insulin delivery under unsupervised, free-living conditions for 4 weeks in adults with type 1 diabetes and HbA 1c below 7·5% is safe and well tolerated, improves glucose control, and reduces hypoglycaemia burden. Larger and longer studies are warranted. Swiss National Science Foundation (P1BEP3_165297), JDRF, UK National Institute for Health Research Cambridge Biomedical Research Centre, and Wellcome Strategic Award (100574/Z/12/Z). Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.

Valuing technology: A qualitative interview study with physicians about insulin pump therapy for children with type 1 diabetes.

PubMed

Shulman, Rayzel; Miller, Fiona A; Daneman, Denis; Guttmann, Astrid

2016-01-01

Insulin pumps for children with type 1 diabetes have been broadly adopted despite equivocal evidence about comparative effectiveness. To understand why and inform policy related to public funding for new technologies, we explored how physicians interpret the value of pumps. We conducted open-ended, semi-structured interviews with 16 physicians from a pediatric diabetes network in Ontario, Canada, and analyzed the data using interpretive description. Respondents recognized that pumps fell short of expectations because they required hard work, as well as family and school support. Yet, pumps were valued for their status as new technologies and as a promising step in developing future technology. In addition, they were valued for their role within a therapeutic relationship, given the context of chronic childhood disease. These findings identify the types of beliefs that influence the adoption and diffusion of technologies. Some beliefs bear on hopes for new technology that may inappropriately hasten adoption, creating excess cost with little benefit. On the other hand, some beliefs identify potential benefits that are not captured in effectiveness studies, but may warrant consideration in resource allocation decisions. Still others suggest the need for remediation, such as those bearing on disparity in pump use by socioeconomic status. Understanding how technologies are valued can help stakeholders decide how to address such beliefs and expectations in funding decisions and implementation protocols. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The impact of baseline hemoglobin A1c levels prior to initiation of pump therapy on long-term metabolic control.

PubMed

Pinhas-Hamiel, Orit; Tzadok, Michal; Hirsh, Galit; Boyko, Valentina; Graph-Barel, Chana; Lerner-Geva, Liat; Reichman, Brian

2010-07-01

This study was done to identify factors influencing long-term metabolic control in youth with type 1 diabetes mellitus (T1DM) treated with an insulin pump. Data were obtained from retrospective chart review of 113 patients (52 males) with T1DM treated with an insulin pump for up to 7 years. Their mean +/- SD age at diagnosis of T1DM was 9.7 +/- 5.1 years, and that at pump therapy initiation was 13.8 +/- 6.1 years. Linear trends and changes in hemoglobin A1c (HbA1c) levels following pump insertion were evaluated according to gender, metabolic control prior to initiation of pump therapy, time from diagnosis of diabetes until pump therapy, age at initiation, and the duration of pump treatment. Mean HbA1c levels of patients with good baseline metabolic control (HbA1c level 9%) control groups (8.1 +/- 0.9% and 8.2 +/- 1.1%, respectively; P < 0.001). However, with time a significant trend for increasing HbA1c level was demonstrated in the group with good metabolic control (P value for trend = 0.004). HbA1c levels of patients with poor baseline metabolic control decreased significantly immediately after pump initiation (9.4 +/- 1.6% vs. 8.0 +/- 1.2%, P = 0.0001) and thereafter remained stable (P value for trend = 0.54). In the multivariable analyses, baseline HbA1c level

Coordinated Basal–Bolus Infusion for Tighter Postprandial Glucose Control in Insulin Pump Therapy

PubMed Central

Bondia, Jorge; Dassau, Eyal; Zisser, Howard; Calm, Remei; Vehí, Josep; Jovanovič, Lois; Doyle, Francis J.

2009-01-01

Background Basal and bolus insulin determination in intensive insulin therapy for type 1 diabetes mellitus (T1DM) are currently considered independently of each other. A new strategy that coordinates basal and bolus insulin infusion to cope with postprandial glycemia in pump therapy is proposed. Superior performance of this new strategy is demonstrated through a formal analysis of attainable performances in an in silico study. Methods The set inversion via interval analysis algorithm has been applied to obtain the feasible set of basal and bolus doses that, for a given meal, mathematically guarantee a postprandial response fulfilling the International Diabetes Federation (IDF) guidelines (i.e., no hypoglycemia and 2 h postprandial glucose below 140 mg/dl). Hypoglycemia has been defined as a glucose value below 70 mg/dl. A 5 h time horizon has been considered for a 70 kg in silico T1DM subject consuming meals in the range of 30 to 80 g of carbohydrates. Results The computed feasible sets demonstrate that current separated basal/bolus strategy dramatically limits the attainable performance. For a nominal basal of 0.8 IU/h leading to a basal glucose of approximately 100 mg/dl, IDF guidelines cannot be fulfilled for meals greater than 50 g of carbohydrates, independent of the bolus insulin computed. However, coordinating the basal and bolus insulin delivery can achieve this. A decrement of basal insulin during the postprandial period is required together with an increase in bolus insulin, in appropriate percentages, which is meal dependent. After 3 h, basal insulin can be restored to its nominal value. Conclusions The new strategy meets IDF guidelines in a typical day, contrary to the standard basal/bolus strategy, yielding a mean 2 h postprandial glucose reduction of 36.4 mg/dl without late hypoglycemia. The application of interval analysis for the computation of feasible sets is demonstrated to be a powerful tool for the analysis of attainable performance in glucose control. PMID:20046653

Analysis of glucose responses to automated insulin suspension with sensor-augmented pump therapy.

PubMed

Ly, Trang T; Nicholas, Jennifer A; Retterath, Adam; Davis, Elizabeth A; Jones, Timothy W

2012-07-01

The advent of sensor-augmented pump therapy with a low-glucose suspend (LGS) function (Medtronic Paradigm Veo System), allowing insulin to be automatically suspended for up to 2 h when sensor glucose falls below a preset threshold, has the potential to reduce the duration of hypoglycemia. In this article, we analyzed blood glucose profiles following a full 2-h insulin suspension activated by the LGS function, as well as examined different patterns of use among patients. Data from a cohort of participants using the Veo System for up to 6 months were analyzed to determine the time and duration of insulin suspension activated by the LGS function. We further evaluated overnight suspend events with no patient response occurring prior to 3:00 a.m., which allowed us to determine the pattern of sensor glucose values with no patient intervention during and after the period of insulin suspension. There were 3,128 LGS events during the 2,493 days evaluated. The median duration was 11.2 min, and 36% of events occurred overnight. There were 126 full 2-h suspend events that occurred overnight with no patient response, occurring before 3:00 a.m. For these events, the mean sensor glucose at the end of the 2-h suspend period was 99 ± 6 mg/dL ([means ± SE] 5.5 ± 0.3 mmol/L). The mean sensor glucose 2 h after insulin delivery resumed was 155 ± 10 mg/dL (8.6 ± 0.6 mmol/L). There were no episodes of severe hypoglycemia or diabetic ketoacidosis. Analyses of sensor glucose patterns following insulin suspension activated by LGS suggest that this technology is safe and unlikely to be associated with adverse outcomes.

Are late-night eating habits and sleep duration associated with glycemic control in adult type 1 diabetes patients treated with insulin pumps?

PubMed

Matejko, Bartlomiej; Kiec-Wilk, Beata; Szopa, Magdalena; Trznadel Morawska, Iwona; Malecki, Maciej T; Klupa, Tomasz

2015-07-01

Little is known about the impact of sleep duration and late-night snacking on glycemic control in patients with type 1 diabetes using insulin pumps. The aim of the present study was to examine whether late-night eating habits and short sleep duration are associated with glycemic control in continuous subcutaneous insulin infusion-treated type 1 diabetic patients. We included 148 consecutive adult type 1 diabetic subjects using an insulin pump (100 women and 48 men). Participants completed a questionnaire regarding sleep duration (classified as short if ≤6 h) and late-night snacking. Other sources of information included medical records and data from blood glucose meters. Glycemic control was assessed by glycated hemoglobin (HbA1c) levels and mean self-monitoring of blood glucose (SMBG) readings. The mean age of patients was 26 years, mean type 1 diabetes duration was 13.4 years and mean HbA1c level was 7.2%. In a univariate regression analysis, sleep duration was a predictor of both HbA1c (β = 0.51, P = 0.01) and SMBG levels (β = 11.4, P = 0.02). Additionally, an association was found between frequent late-night snacking and higher SMBG readings (often snacking β = 18.1, P = 0.05), but not with increased HbA1c levels. In the multivariate linear regression, independent predictors for HbA1c and SMBG were sleep duration and patient age. In a univariate logistic regression, sleep duration and frequency of late-night snacking were not predictors of whether HbA1c target levels were achieved. Short sleep duration, but not late-night snacking, seems to be associated with poorer glycemic control in type 1 diabetic patients treated with continuous subcutaneous insulin infusion.

A Study of the Carbohydrate-to-Insulin Ratio in Pregnant Women with Type 1 Diabetes on Pump Treatment.

PubMed

Bongiovanni, Marzia; Fresa, Raffaella; Visalli, Natalia; Bitterman, Olimpia; Suraci, Concetta; Napoli, Angela

2016-06-01

The aim of this study was to assess carbohydrate (CHO)-to-insulin ratio (CHO/IR) values in pregnant women with type 1 diabetes and to describe differences in CHO/IR across each week of pregnancy. This was a multicenter, retrospective, observational study (2006-2012) of 101 white pregnant women with a mean age of 32 (range, 18-43) years who had type 1 diabetes and were under continuous subcutaneous insulin infusion (CSII) therapy. These patients had the following characteristics: type 1 diabetes duration was 1 year (range, 1-31 years), the pregestational glycosylated hemoglobin level was 6.9% (range, 6.8-12.1%), the median weight gain during pregnancy was 14 kg (-3; 25 kg), with delivery at 37 weeks (range, 30-40 weeks), and the child had a birth weight of 3.530 kg (range, 1.480-5.250 kg). The CHO/IR was measured by dividing the CHO (in g) of each meal by insulin unit injected to acquire and maintain the following glycemic targets: fasting <90 mg/dL and 1-h postprandial <130 mg/dL. Simultaneously, CHO/IR indices were calculated through 500/total daily doses of insulin and 300/total daily doses of insulin. Education and management before and during pregnancy were in agreement with Italian Association of Dietitians, Association of Medical Diabetologists, and Italian Society of Diabetology recommendations. Data were analyzed using SPSS software (version 20.0; SPSS, Inc., Chicago, IL). The CHO/IR decreased on average from 9.6 (5-18) to 5.4 (2.3-8) at breakfast, from 10 (3.5-16) to 8.4 (3.0-17.8) at lunch, and from 12.5 (8-20) to 6.1 (4.2-12) at dinner. The CHO/IR calculated using the "500 rule" decreased from 14.3 (10-20.3) to 8.6 (4.1-15.9). Using the "300 rule," the ratios decreased from 8.5 (6-12.1) to 5.2 (2.4-9.5). The bivariate correlation between the values calculated more appropriate values using the "300 rule" for breakfast and the "500 rule" for lunch and dinner across all weeks of pregnancy. CHO/IR reduction in pregnancy is likely due to an increase in insulin resistance.

Allergic contact dermatitis caused by isobornyl acrylate in OmniPod, an innovative tubeless insulin pump.

PubMed

Raison-Peyron, Nadia; Mowitz, Martin; Bonardel, Nathalie; Aerts, Olivier; Bruze, Magnus

2018-04-10

The frequency of allergic contact dermatitis caused by (meth)acrylates is increasing worldwide, and isobornyl acrylate (IBOA) has been identified as a culprit sensitizer in FreeStyle Libre, a medical device used by diabetic patients. To report on 4 patients sensitized to IBOA contained in OmniPod, a new, tubeless insulin pump, and to describe the clinical and chemical analytical work-up. Four patients with eczematous skin eruptions after using OmniPod, including 2 with previous adverse skin reactions to FreeStyle Libre, were patch tested with a baseline series and additional (meth)acrylates, including IBOA in several concentrations and/or vehicles. Gas chromatography-mass spectrometry (GC-MS) was used to identify the presence of IBOA in OmniPod. All patients were shown to be sensitized to IBOA. GC-MS identified IBOA in OmniPod, with the highest concentrations being found in the unit itself and not in the adhesive patch. The OmniPod tubeless insulin pump is another source of IBOA, and its use may lead to primary sensitization to this acrylate, or may provoke elicitation of allergic contact dermatitis in previously sensitized patients. Our cases highlight the need to obtain satisfactory cooperation from pharmaceutical companies involved in the manufacture of these widely used medical devices. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evaluation of current trends and recent development in insulin therapy for management of diabetes mellitus.

PubMed

Nawaz, Muhammad Sarfraz; Shah, Kifayat Ullah; Khan, Tahir Mehmood; Rehman, Asim Ur; Rashid, Haroon Ur; Mahmood, Sajid; Khan, Shahzeb; Farrukh, Muhammad Junaid

2017-12-01

Diabetes mellitus is a major health problem in developing countries. There are various insulin therapies to manage diabetes mellitus. This systematic review evaluates various insulin therapies for management of diabetes mellitus worldwide. This review also focuses on recent developments being explored for better management of diabetes mellitus. We reviewed a number of published articles from 2002 to 2016 to find out the appropriate management of diabetes mellitus. The paramount parameters of the selected studies include the insulin type & its dose, type of diabetes, duration and comparison of different insulin protocols. In addition, various newly developed approaches for insulin delivery with potential output have also been evaluated. A great variability was observed in managing diabetes mellitus through insulin therapy and the important controlling factors found for this therapy include; dose titration, duration of insulin use, type of insulin used and combination therapy of different insulin. A range of research articles on current trends and recent advances in insulin has been summarized, which led us to the conclusion that multiple daily insulin injections or continuous subcutaneous insulin infusion (insulin pump) is the best method to manage diabetes mellitus. In future perspectives, development of the oral and inhalant insulin would be a tremendous breakthrough in Insulin therapy. Copyright © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Insulin fibrillation and protein design: topological resistance of single-chain analogs to thermal degradation with application to a pump reservoir.

PubMed

Phillips, Nelson B; Whittaker, Jonathan; Ismail-Beigi, Faramarz; Weiss, Michael A

2012-03-01

Insulin is susceptible to thermal fibrillation, a misfolding process that leads to nonnative cross-β assembly analogous to pathological amyloid deposition. Pharmaceutical formulations are ordinarily protected from such degradation by sequestration of the susceptible monomer within native protein assemblies. With respect to the safety and efficacy of insulin pumps, however, this strategy imposes an intrinsic trade-off between pharmacokinetic goals (rapid absorption and clearance) and the requisite physical properties of a formulation (prolonged shelf life and stability within the reservoir). Available rapid-acting formulations are suboptimal in both respects; susceptibility to fibrillation is exacerbated even as absorption is delayed relative to the ideal specifications of a closed-loop system. To circumvent this molecular trade-off, we exploited structural models of insulin fibrils and amyloidogenic intermediates to define an alternative protective mechanism. Single-chain insulin (SCI) analogs were shown to be refractory to thermal fibrillation with maintenance of biological activity for more than 3 months under conditions that promote the rapid fibrillation and inactivation of insulin. The essential idea exploits an intrinsic incompatibility between SCI topology and the geometry of cross-β assembly. A peptide tether was thus interposed between the A- and B-chains whose length was (a) sufficiently long to provide the "play" needed for induced fit of the hormone on receptor binding and yet (b) sufficiently short to impose a topological barrier to fibrillation. Our findings suggest that ultrastable monomeric SCI analogs may be formulated without protective self-assembly and so permit simultaneous optimization of pharmacokinetics and reservoir life. © 2012 Diabetes Technology Society.

Insulin pump therapy: what is the evidence for using different types of boluses for coverage of prandial insulin requirements?

PubMed

Heinemann, Lutz

2009-11-01

Bolus infusion of insulin along with a meal is a standard procedure with continuous subcutaneous insulin infusion. Modern insulin pumps allow applying this bolus in four different ways: infusion of the total dose at once or splitting the dose into two boluses, infusion of a part of the bolus in the usual manner plus infusion of the other part over a prolonged period of time (with a higher infusion rate than the basal rate), or infusion of the total dose in the form of an elevated basal rate. Depending on the composition of the given meal and its glycemic index, this is an attempt to match the circulating insulin levels to the rate of glucose absorption from the gut in order to minimize postprandial glycemic excursions. However, in the framework of evidence-based medicine, the benefits of this approach should be proven in appropriately designed clinical studies. Performance of meal-related studies requires careful attention to many aspects in order to allow meaningful evaluation of a given intervention (i.e., type of bolus). Critical evaluation of the clinical experimental studies and the one clinical study published about the impact of different types of boluses on postprandial metabolic control revealed fundamental shortcomings in study design and performance in these studies. Insufficient establishment of comparable preprandial glycemia and insulinemia on the different study days within and between the patients studied is one key aspect. Therefore, the recommendation made in most of these studies (i.e., use of dual-wave bolus) has to be accepted with care, until we have better evidence.

The numerical simulation based on CFD of hydraulic turbine pump

NASA Astrophysics Data System (ADS)

Duan, X. H.; Kong, F. Y.; Liu, Y. Y.; Zhao, R. J.; Hu, Q. L.

2016-05-01

As the functions of hydraulic turbine pump including self-adjusting and compensation with each other, it is far-reaching to analyze its internal flow by the numerical simulation based on CFD, mainly including the pressure field and the velocity field in hydraulic turbine and pump.The three-dimensional models of hydraulic turbine pump are made by Pro/Engineer software;the internal flow fields in hydraulic turbine and pump are simulated numerically by CFX ANSYS software. According to the results of the numerical simulation in design condition, the pressure field and the velocity field in hydraulic turbine and pump are analyzed respectively .The findings show that the static pressure decreases systematically and the pressure gradient is obvious in flow area of hydraulic turbine; the static pressure increases gradually in pump. The flow trace is regular in suction chamber and flume without spiral trace. However, there are irregular traces in the turbine runner channels which contrary to that in flow area of impeller. Most of traces in the flow area of draft tube are spiral.

Master Pump Shutdown MPS Software Quality Assurance Plan (SQAP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

BEVINS, R.R.

2000-09-20

The MPSS Software Quality Assurance (SQAP) describes the tools and strategy used in the development of the MPSS software. The document also describes the methodology for controlling and managing changes to the software.

Insulin Pumps

MedlinePlus

... Risk? Home Prevention Diagnosing Diabetes and Learning About Prediabetes Type 2 Diabetes Risk Test Lower Your Risk ... Diagnosis Lower Your Risk Risk Test Alert Day Prediabetes My Health Advisor Tools to Know Your Risk ...

Routine sensor-augmented pump therapy in type 1 diabetes: the INTERPRET study.

PubMed

Nørgaard, Kirsten; Scaramuzza, Andrea; Bratina, Natasa; Lalić, Nebojsa M; Jarosz-Chobot, Przemyslaw; Kocsis, Győző; Jasinskiene, Edita; De Block, Christophe; Carrette, Odile; Castañeda, Javier; Cohen, Ohad

2013-04-01

Sensor-augmented pump (SAP) therapy can improve glycemic control, compared with multiple daily insulin injections or with insulin pump therapy alone, without increasing the risk of hypoglycemia. A 12-month observational study in patients with type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII), upon the introduction of continuous glucose monitoring (CGM), was conducted in 15 countries (in Europe and in Israel) to document the real-life use of SAP and assess which variables are associated with improvement in type 1 diabetes management. Data from 263 patients (38% male; mean age, 28.0 ± 15.7 years [range, 1-69 years]; body mass index, 23.3 ± 4.9 kg/m(2); diabetes duration, 13.9 ± 10.7 years; CSII duration, 2.6 ± 3 years) were collected. Baseline mean glycated hemoglobin A1c (HbA1c) was 8.1 ± 1.4%; 82% had suboptimal HbA1c (≥ 7%). The average sensor use for 12 months was 30% (range, 0-94%), and sensor use decreased with time (first 3 months, 37%; last 3 months, 27%). Factors associated with improvement in HbA1c after 12 months in patients with baseline HbA1c ≥ 7% were high baseline HbA1c (P<0.001), older age group (P<0.001), and more frequent sensor use (P = 0.047). Significantly less hospitalization, increased treatment satisfaction, and reduced fear of hypoglycemia were reported after 12 months of SAP. This is the largest and longest multicenter prospective observational study providing real-life data on SAP. These results are consistent with those of controlled trials showing the effectiveness of CGM in pump users.

Reexamining the Hypoglycemia Fear Survey for Parents of Young Children in a Sample of Children Using Insulin Pumps.

PubMed

Patton, Susana R; Noser, Amy E; Clements, Mark A; Dolan, Lawrence M; Powers, Scott W

2017-02-01

We update the psychometric properties of the Hypoglycemia Fear Survey-Parents of Young Children (HFS-PYC), a 26-item measure of parents' hypoglycemia fear for young children using an insulin pump. We combined three similar datasets for the analyses. The data analyzed included parents' responses to the HFS-PYC and a demographic form. For a subset of children (n = 91), we also analyzed self-monitoring of blood glucose data. We used confirmatory factor analysis (CFA) to confirm the measure's original factor structure. Additional analyses examined reliability and validity of a revised HFS-PYC for parents of young children using pumps. We analyzed data from 116 parents (93% mothers). Mean child age and HbA1c were 5.2 ± 1.3 years and 8.2% ± 1.1%, respectively. CFA identified a 22-item two-factor solution (χ 2 (208, n = 116) = 368.688, P < 0.001, root mean square error of approximation = 0.08, comparative fit index = 0.94, and Tucker-Lewis index = 0.93) with factors corresponding to the original subscales: worry and behavior. The revised subscales demonstrated at least adequate internal consistency (Cronbach's alpha >0.65). Correlations revealed significant negative associations between current HFS-PYC worry scores and children's mean daily blood glucose and percent of very high glucose levels per day, suggesting less fear among parents of young children with elevated glycemic levels. In addition, there was a positive association with the percent of glucose levels in target, suggesting greater hypoglycemia fear among parents of children who have better control. Results provide preliminary evidence for the reliability and validity of a reduced 22-item HFS-PYC for parents of children using insulin pumps.

Electromagnetic interference from electronic devices used in the management of type 1 diabetes can impair the performance of an avalanche transceiver in search mode.

PubMed

Miller, Steven C M

2015-06-01

Portable electronic devices play an important role in the management of type 1 diabetes mellitus. Electromagnetic interference from electronic devices has been shown to impair the function of an avalanche transceiver in search mode (but not in transmitting mode). This study investigates the influence of electromagnetic interference from diabetes devices on a searching avalanche beacon. The greatest distance at which an avalanche transceiver (in search mode) could accurately indicate the location of a transmitting transceiver was assessed when portable electronic devices (including an insulin pump and commonly used real-time continuous subcutaneous glucose monitoring system [rtCGMS]) were held in close proximity to each transceiver. The searching transceiver could accurately locate a transmitted signal at a distance of 30 m when used alone. This distance was unchanged by the Dexcom G4 rtCGMS, but was reduced to 10 m when the Medtronic Guardian rtCGMS was held close (within 30 cm) to the receiving beacon. Interference from the Animas Vibe insulin pump reduced this distance to 5 m, impairing the searching transceiver in a manner identical to the effect of a cell phone. Electromagnetic interference produced by some diabetes devices when held within 30 cm of a searching avalanche transceiver can impair the ability to locate a signal. Such interference could significantly compromise the outcome of a companion rescue scenario. Further investigation using other pumps and rtCGMS devices is required to evaluate all available diabetes electronics. Meantime, all electronic diabetes devices including rtCGMS and insulin pumps should not be used within 30 cm of an avalanche transceiver. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

A model of insulin delivery by a controlled release micropump.

PubMed

Allen, D G; Sefton, M V

1986-01-01

A model has been developed to describe the delivery of insulin from a controlled release micropump (CRM). Basal delivery was provided by diffusion due to a concentration difference driving force across the CRM. This was modelled by considering the CRM to be a series of one-dimensional steady-state diffusion resistances. This delivery model was used to size prototypes and identify the piston, foam and the pump outlet as the controlling resistances to basal insulin transport. Augmented delivery by the CRM was achieved by repeated compression of a foam disk by a mild steel piston which was driven by a solenoid (tested voltage range 0-173 V DC; 5 msec "on" time; frequency 20-40 min-1). The increased delivery was attributed to the combination of mixing inside the pump barrel and displacement of barrel contents into the downstream reservoir. This action was approximated by a three-compartment model, which considered the CRM to consist of a well-mixed upstream reservoir and pump barrel (with a downstream reservoir) separated by two resistances: a constant upstream membrane resistance, (KmAm)-1, and a variable downstream mixing rate resistance, (Qd)-1. A least squares fit of the model to experimental data showed Qd to increase with the cube of the force on the piston and linearly with the compression frequency. In agreement with experimental results, the model predicted the upstream membrane to be rate controlling only at augmented pump resistances close to the value (KmAm)-1. These models were used to design an improved prototype (VIII) which is now being evaluated in vivo in pancreatectomized dogs for its efficacy in restoring and sustaining normoglycemia.

Metabolic control after years of completing a clinical trial on sensor-augmented pump therapy.

PubMed

Quirós, Carmen; Giménez, Marga; Orois, Aida; Conget, Ignacio

2015-11-01

Sensor-augmented pump (SAP) therapy has been shown to be effective and safe for improving metabolic control in patients with type 1 diabetes mellitus (T1DM) in a number of trials. Our objective was to assess glycemic control in a group of T1DM patients on insulin pump or SAP therapy after years of participating in the SWITCH (Sensing With Insulin pump Therapy To Control HbA1c) trial and their return to routine medical monitoring. A retrospective, observational study of 20 patients who participated in the SWITCH trial at our hospital from 2008 to 2010. HbA1c values were compared at the start, during (at the end of the periods with/without SAP use - Sensor On/Sensor Off period respectively - of the cross-over design), and 3 years after study completion. HbA1c values of patients who continued SAP therapy (n=6) or only used insulin pump (n=14) were also compared. Twenty patients with T1DM (44.4±9.3 years, 60% women, baseline HbA1c level 8.43±0.55%) were enrolled into the SWITCH study). Three years after study completion, HbA1c level was 7.79±0.77 in patients on pump alone, with no significant change from the value at the end of the Off period of the study (7.85±0.57%; p=0.961). As compared to the end of the On period, HbA1c worsened less in patients who remained on SAP than in those on pump alone (0.18±0.42 vs. 0.55±0.71%; p=0.171), despite the fact that levels were similar at study start (8.41±0.60 vs. 8.47±0.45; p=0.831) and at the end of the On period (7.24±0.48 vs. 7.38±0.61; p=0.566). Frequency of CGM use in patients who continued SAP therapy was high (61.2% of the time in the last 3 months). Our study suggests that the additional benefit of SAP therapy achieved in a clinical trial may persist in the long term in routine clinical care of patients with T1DM. Copyright © 2015 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Predicting Human Subcutaneous Glucose Concentration in Real Time: A Universal Data-Driven Approach

DTIC Science & Technology

2011-09-01

insulin for at least 12 mo, and had glycated hemoglobin ( HbA1c ) >6.1%. In the Guardian study, subjects were included if they were between 3 and 7 yr...old or between 12 and 18 yr old, had been diagnosed with type 1 diabetes for more than 1 yr, had been using an insulin pump, and had HbA1c ≤ 10.0...oral agents, basal insulin, or both for at least 3 mo, and had HbA1c between 7% and 12%. Predicting Human Subcutaneous Glucose Concentration in

A web-based study of the relationship of duration of insulin pump infusion set use and fasting blood glucose level in adults with type 1 diabetes.

PubMed

Sampson Perrin, Alysa J; Guzzetta, Russell C; Miller, Kellee M; Foster, Nicole C; Lee, Anna; Lee, Joyce M; Block, Jennifer M; Beck, Roy W

2015-05-01

To evaluate the impact of infusion set use duration on glycemic control, we conducted an Internet-based study using the T1D Exchange's online patient community, Glu ( myGlu.org ). For 14 days, 243 electronically consented adults with type 1 diabetes (T1D) entered online that day's fasting blood glucose (FBG) level, the prior day's total daily insulin (TDI) dose, and whether the infusion set was changed. Mean duration of infusion set use was 3.0 days. Mean FBG level was higher with each successive day of infusion set use, increasing from 126 mg/dL on Day 1 to 133 mg/dL on Day 3 to 147 mg/dL on Day 5 (P<0.001). TDI dose did not vary with increased duration of infusion set use. Internet-based data collection was used to rapidly conduct the study at low cost. The results indicate that FBG levels increase with each additional day of insulin pump infusion set use.

Closed loop insulin delivery in diabetes.

PubMed

Battelino, Tadej; Omladič, Jasna Šuput; Phillip, Moshe

2015-06-01

The primary goal of type 1 diabetes treatment is attaining near-normal glucose values. This currently remains out of reach for most people with type 1 diabetes despite intensified insulin treatment in the form of insulin analogues, educational interventions, continuous glucose monitoring, and sensor augmented insulin pump. The main remaining problem is risk of hypoglycaemia, which cannot be sufficiently reduced in all patient groups. Additionally, patients' burn-out often develops with years of tedious day-to-day diabetes management, rendering available diabetes-related technology less efficient. Over the past 40 years, several attempts have been made towards computer-programmed insulin delivery in the form of closed loop, with faster developments especially in the past decade. Automated insulin delivery has reduced human error in glycaemic control and considerably lessened the burden of routine self-management. In this chapter, data from randomized controlled trials with closed-loop insulin delivery that included type 1 diabetes population are summarized, and an evidence-based vision for possible routine utilization of closed loop is provided. Copyright © 2015 Elsevier Ltd. All rights reserved.

Projections for insulin treatment for diabetics.

PubMed

Cao, Ying; Lam, Laura

2002-06-01

The evolution of insulin treatment of diabetes has dramatically changed the natural course of this disease. Modern recombinant DNA technology has brought about many new insulin analogues with improved pharmacokinetics, resulting in better glycemic control. In addition, improved insulin delivery systems, such as insulin pumps and pens, have been introduced to provide convenience and to enhance patient compliance. Efforts are currently being devoted to developing noninvasive insulin formulations, such as oral and pulmonary insulin. A number of products are at different stages of clinical trials. Meanwhile, the quest for a permanent cure for diabetes continues. The frontier of diabetes research has gone through a period of substantial expansion, with the emergence of new areas that include gene therapy, islet cell transplantation and diabetic vaccine. Technological breakthroughs, such as recombinant DNA, nanotechnology, microarray-aided genomics and proteomics, will provide more profound insights into the pathogenesis, and the immunological and biological basis of diabetes. Our growing knowledge in these areas will ultimately contribute to the discovery of preventive methods against or a cure for this disease.

Development (design and systematization) of HMS Group pump ranges

NASA Astrophysics Data System (ADS)

Tverdokhleb, I.; Yamburenko, V.

2017-08-01

The article reveals the need for pump range charts development for different applications and describes main principles used by HMS Group. Some modern approaches to pump selection are reviewed and highlighted the need for pump compliance with international standards and modern customer requirements. Even though pump design types are similar for different applications they need adjustment to specific requirements, which gets manufacturers develop their particular design for each pump range. Having wide pump ranges for different applications enables to create pump selection software, facilitating manufacturers to prepare high quality quotations in shortest time.

Depressive Symptoms, Emotion Dysregulation, and Bulimic Symptoms in Youth With Type 1 Diabetes

PubMed Central

Young-Hyman, Deborah L.; Peterson, Claire M.; Fischer, Sarah; Markowitz, Jessica T.; Muir, Andrew B.; Laffel, Lori M.

2016-01-01

This study evaluated the associations between depressive symptoms, emotion dysregulation and bulimic symptoms in youth with type 1 diabetes (T1D) in the context of the diagnosis and treatment of T1D. Study participants were 103 youth in 2 distinct groups: newly diagnosed (New) or transitioning to pump therapy (continuous subcutaneous insulin infusion [CSII]; “Pump”), who completed questionnaires regarding symptoms of depression, emotion dysregulation, and bulimia. Glycemic control (A1c), height, weight, and questionnaires were evaluated within 10 days of diagnosis (n = 58) or at education/clinic visit before starting insulin utilizing CSII (n = 45). In the newly diagnosed group, only depression accounted for significant variance in bulimia scores (β = .47, P < .01). For the group with disease treatment experience (Pump), but not for the newly diagnosed group (New), greater depressive symptoms and emotion dysregulation were associated with greater bulimic symptoms. Depressive symptoms and emotion dysregulation, an indicator of poor coping/behavioral control, could help explain adoption of disordered eating behaviors in youth with T1D who are transitioning to pump therapy. PMID:27137457

[The diabetic child and the specifics of insulin therapy].

PubMed

Dirlewanger, M; Perrenoud, L; Castellsague-Perolini, M; Schwitzgebel, V M

2007-04-18

The incidence of diabetes type I has increased considerably in young children with an annual increase in Switzerland of 23,8% over the last ten years. The development of rapid acting and long acting analogues allowed a significant progress in treatment. Multiple daily insulin injections together with carbohydrate counting as well as continuous subcutaneous insulin infusion (CSII) improved the quality of life and led to an increased daily flexibility. The incidence of severe hypoglycaemic events has decreased at the same time metabolic control improved. The development of interstitial glucose measurement (online) coupled to the insulin pump represents a step further towards the artificial pancreas. The new therapeutic strategies of immunomodulation will hopefully lead to secondary and tertiary prevention of diabetes.

Use of Diabetes Data Management Software Reports by Health Care Providers, Patients With Diabetes, and Caregivers Improves Accuracy and Efficiency of Data Analysis and Interpretation Compared With Traditional Logbook Data

PubMed Central

Hinnen, Deborah A.; Buskirk, Ann; Lyden, Maureen; Amstutz, Linda; Hunter, Tracy; Parkin, Christopher G.; Wagner, Robin

2014-01-01

Background: We assessed users’ proficiency and efficiency in identifying and interpreting self-monitored blood glucose (SMBG), insulin, and carbohydrate intake data using data management software reports compared with standard logbooks. Method: This prospective, self-controlled, randomized study enrolled insulin-treated patients with diabetes (PWDs) (continuous subcutaneous insulin infusion [CSII] and multiple daily insulin injection [MDI] therapy), patient caregivers [CGVs]) and health care providers (HCPs) who were naïve to diabetes data management computer software. Six paired clinical cases (3 CSII, 3 MDI) and associated multiple-choice questions/answers were reviewed by diabetes specialists and presented to participants via a web portal in both software report (SR) and traditional logbook (TL) formats. Participant response time and accuracy were documented and assessed. Participants completed a preference questionnaire at study completion. Results: All participants (54 PWDs, 24 CGVs, 33 HCPs) completed the cases. Participants achieved greater accuracy (assessed by percentage of accurate answers) using the SR versus TL formats: PWDs, 80.3 (13.2)% versus 63.7 (15.0)%, P < .0001; CGVs, 84.6 (8.9)% versus 63.6 (14.4)%, P < .0001; HCPs, 89.5 (8.0)% versus 66.4 (12.3)%, P < .0001. Participants spent less time (minutes) with each case using the SR versus TL formats: PWDs, 8.6 (4.3) versus 19.9 (12.2), P < .0001; CGVs, 7.0 (3.5) versus 15.5 (11.8), P = .0005; HCPs, 6.7 (2.9) versus 16.0 (12.0), P < .0001. The majority of participants preferred using the software reports versus logbook data. Conclusions: Use of the Accu-Chek Connect Online software reports enabled PWDs, CGVs, and HCPs, naïve to diabetes data management software, to identify and utilize key diabetes information with significantly greater accuracy and efficiency compared with traditional logbook information. Use of SRs was preferred over logbooks. PMID:25367012

The ASPIRE study: design and methods of an in-clinic crossover trial on the efficacy of automatic insulin pump suspension in exercise-induced hypoglycemia.

PubMed

Brazg, Ronald L; Bailey, Timothy S; Garg, Satish; Buckingham, Bruce A; Slover, Robert H; Klonoff, David C; Nguyen, Xuan; Shin, John; Welsh, John B; Lee, Scott W

2011-11-01

The Paradigm®Veo™ System includes a low glucose suspend (LGS) feature which suspends insulin delivery when a prespecified glucose threshold setting is reached by the associated continuous glucose monitoring (CGM) sensor. The ASPIRE (Automation to Simulate Pancreatic Insulin REsponse) study is a multicenter, in-clinic, randomized, crossover study to examine the efficacy of LGS in exercise-induced hypoglycemia. Insulin-pump users underwent two separate exercise sessions, one with the LGS feature set to suspend insulin (LGS-on) when the CGM-detected glucose concentration was ≤ 70 mg/dl and one with the LGS feature off. Exercise sessions were conducted after an overnight fast and with initial plasma glucose level as measured by the YSI 2300 STAT Plus glucose analyzer (YSI) of 100-140 mg/dl. Subjects exercised until their YSI value fell to ≤ 85 mg/dl; subsequent YSI values <70 mg/dl were recorded for up to 4 h to measure the duration and nadir of hypoglycemia. The protocol required that subjects with YSI values <50 or >300 mg/dl were rescued with carbohydrates or insulin, respectively, based on the provider's recommendation. The primary end point was comparison of duration and severity of hypoglycemia between LGS-on and LGS-off sessions. Secondary end points included areas under the glucose concentration curve, CGM sensor accuracy, and last YSI glucose. Device- and procedure-related adverse events and serious adverse events were recorded. Fifty adults and teenagers (17-58 years) with type 1 diabetes were randomized. Study completion is expected in November 2011. © 2011 Diabetes Technology Society.

In silico preclinical trials: a proof of concept in closed-loop control of type 1 diabetes.

PubMed

Kovatchev, Boris P; Breton, Marc; Man, Chiara Dalla; Cobelli, Claudio

2009-01-01

Arguably, a minimally invasive system using subcutaneous (s.c.) continuous glucose monitoring (CGM) and s.c. insulin delivery via insulin pump would be a most feasible step to closed-loop control in type 1 diabetes mellitus (T1DM). Consequently, diabetes technology is focusing on developing an artificial pancreas using control algorithms to link CGM with s.c. insulin delivery. The future development of the artificial pancreas will be greatly accelerated by employing mathematical modeling and computer simulation. Realistic computer simulation is capable of providing invaluable information about the safety and the limitations of closed-loop control algorithms, guiding clinical studies, and out-ruling ineffective control scenarios in a cost-effective manner. Thus computer simulation testing of closed-loop control algorithms is regarded as a prerequisite to clinical trials of the artificial pancreas. In this paper, we present a system for in silico testing of control algorithms that has three principal components: (1) a large cohort of n=300 simulated "subjects" (n=100 adults, 100 adolescents, and 100 children) based on real individuals' data and spanning the observed variability of key metabolic parameters in the general population of people with T1DM; (2) a simulator of CGM sensor errors representative of Freestyle Navigator™, Guardian RT, or Dexcom™ STS™, 7-day sensor; and (3) a simulator of discrete s.c. insulin delivery via OmniPod Insulin Management System or Deltec Cozmo(®) insulin pump. The system has been shown to represent adequate glucose fluctuations in T1DM observed during meal challenges, and has been accepted by the Food and Drug Administration as a substitute to animal trials in the preclinical testing of closed-loop control strategies. © Diabetes Technology Society

MANAGEMENT OF DIABETES DURING AIR TRAVEL: A SYSTEMATIC LITERATURE REVIEW OF CURRENT RECOMMENDATIONS AND THEIR SUPPORTING EVIDENCE.

PubMed

Pavela, James; Suresh, Rahul; Blue, Rebecca S; Mathers, Charles H; Belalcazar, L Maria

2018-02-01

Individuals with diabetes are increasingly seeking pretravel advice, but updated professional recommendations remain scant. We performed a systematic review on diabetes management during air travel to summarize current recommendations, assess supporting evidence, and identify areas of future research. A systematic review of the English literature on diabetes management during air travel was undertaken utilizing PubMed and MEDLINE. Publications regarding general travel advice; adjustment of insulin and noninsulin therapies; and the use of insulin pumps, glucometers and subcutaneous glucose sensors at altitude were included. Gathered information was used to create an updated summary of glucose-lowering medication adjustment during air travel. Sixty-one publications were identified, most providing expert opinion and few offering primary data (47 expert opinion, 2 observational studies, 2 case reports, 10 device studies). General travel advice was uniform, with increasing attention to preflight security. Indications for oral antihyperglycemic therapy adjustments varied. There were few recommendations on contemporary agents and on nonhypoglycemic adverse events. There was little consensus on insulin adjustment protocols, many antedating current insulin formulations. Most publications advocated adjusting insulin pump time settings after arrival; however, there was disagreement on timing and rate adjustments. Glucometers and subcutaneous glucose sensors were reported to be less accurate at altitude, but not to an extent that would preclude their clinical use. Recommendations for diabetes management during air travel vary significantly and are mostly based on expert opinion. Data from systematic investigation on glucose-lowering medication adjustment protocols may support the development of a future consensus statement. CSII = continuous subcutaneous insulin infusion (device) DPP-4 = dipeptidyl peptidase 4 EGA = error grid analysis GDH = glucose dehydrogenase GOX = glucose oxidase GLP1 = glucagon-like peptide-1 NPH = neutral protamine Hagedorn SGLT2 = sodium-glucose cotransporter-2.

Insulin Glulisine (rDNA origin) Injection

MedlinePlus

... the reservoir and change the tubing, needle, and infusion site (spot where the pump is attached to ... body) at least every 48 hours. If the infusion site is red, itchy, or thickened, tell your ...

Light Control of Insulin Release and Blood Glucose Using an Injectable Photoactivated Depot.

PubMed

Sarode, Bhagyesh R; Kover, Karen; Tong, Pei Y; Zhang, Chaoying; Friedman, Simon H

2016-11-07

In this work we demonstrate that blood glucose can be controlled remotely through light stimulated release of insulin from an injected cutaneous depot. Human insulin was tethered to an insoluble but injectable polymer via a linker, which was based on the light cleavable di-methoxy nitrophenyl ethyl (DMNPE) group. This material was injected into the skin of streptozotocin-treated diabetic rats. We observed insulin being released into the bloodstream after a 2 min trans-cutaneous irradiation of this site by a compact LED light source. Control animals treated with the same material, but in which light was blocked from the site, showed no release of insulin into the bloodstream. We also demonstrate that additional pulses of light from the light source result in additional pulses of insulin being absorbed into circulation. A significant reduction in blood glucose was then observed. Together, these results demonstrate the feasibility of using light to allow for the continuously variable control of insulin release. This in turn has the potential to allow for the tight control of blood glucose without the invasiveness of insulin pumps and cannulas.

A fuzzy logic controller for hormone administration using an implantable pump

NASA Technical Reports Server (NTRS)

Coles, L. Stephen; Wells, George H., Jr.

1994-01-01

This paper describes the requirements for a Fuzzy Logic Controller for the physiologic administration of hormones by means of a FDA-approved surgically implantable infusion pump. Results of a LabVIEW computer simulation for the administration of insulin for diabetic adult patients as well as human growth hormone for pediatric patients are presented. A VHS video tape of the simulation in action has been prepared and is available for viewing.

Treatment of mild-to-moderate hypoglycemia in patients with type 1 diabetes treated with insulin pump therapy: are current recommendations effective?

PubMed

Gingras, Véronique; Desjardins, Katherine; Smaoui, Mohamed Raef; Savard, Valérie; Messier, Virginie; Haidar, Ahmad; Legault, Laurent; Rabasa-Lhoret, Rémi

2018-03-01

Mild-to-moderate hypoglycemia (blood glucose < 4.0 mmol/L) is recommended to be treated with 15 g of carbohydrates and to repeat the treatment if hypoglycemia persists after 15 min. This recommendation was established before intensive insulin therapy and based on studies using insulin with different pharmacokinetic profiles from actual insulin analogs showing that 15 g of glucose increases blood glucose by ~ 1.5 mmol/L in 15 min. We aimed to explore the effect of current recommended treatment of mild-to-moderate hypoglycemia in type 1 diabetes (T1D) participants and factors associated with treatment effectiveness. This is a secondary analysis from three observational inpatient studies with a standardized and supervised treatment (16 g carbohydrates) of hypoglycemia (< 3.3 mmol/L with symptoms or < 3.0 mmol/L without symptom) in participants (47 adults-10 adolescents) with T1D using continuous subcutaneous insulin infusion ("insulin pumps"; CSII)). Twenty-seven participants presented a total of 48 hypoglycemia episodes treated by a single intake of 16 g of carbohydrates. Time required for normoglycemia recovery was 19.5 ± 12.0 min. The rise in plasma glucose following treatment was 0.85 ± 0.66 mmol/L in 15 min. Eighteen episodes (38%) were resolved (> 4.0 mmol/L) 15-min post-treatment. Glycemia at the time of treatment (< 3.2 mmol/L; p < 0.001) and a higher proportion of total daily insulin from basal doses (p = 0.03) were associated with a slower post-treatment plasma glucose rise. These results raise the possibility that sixteen grams of carbohydrates could be insufficient to treat a large proportion of hypoglycemia episodes in T1D patients treated with CSII. Factors affecting treatment effectiveness need to be investigated.

Managing hypoglycaemia.

PubMed

Iqbal, Ahmed; Heller, Simon

2016-06-01

Intensive glycaemic control reduces the diabetic microvascular disease burden but iatrogenic hypoglycaemia is a major barrier preventing tight glycaemic control because of the limitations of subcutaneous insulin preparations and insulin secretagogues. Severe hypoglycaemia is uncommon early in the disease as robust physiological defences, particularly glucagon and adrenaline release, limit falls in blood glucose whilst associated autonomic symptoms drive patients to take action by ingesting oral carbohydrate. With increasing diabetes duration, glucagon release is progressively impaired and sympatho-adrenal responses are activated at lower glucose levels. Repeated hypoglycaemic episodes contribute to impaired defences, increasing the risk of severe hypoglycaemia in a vicious downward spiral. Managing hypoglycaemia requires a systematic clinical approach with structured insulin self-management training and support of experienced diabetes educators. Judicious use of technologies includes insulin analogues, insulin pump therapy, continuous glucose monitoring, and in a few cases islet cell transplantation. Some individuals require specialist psychological support. Copyright © 2016. Published by Elsevier Ltd.

Therapeutics of diabetes mellitus: focus on insulin analogues and insulin pumps.

PubMed

Valla, Vasiliki

2010-01-01

Inadequately controlled diabetes accounts for chronic complications and increases mortality. Its therapeutic management aims in normal HbA1C, prandial and postprandial glucose levels. This review discusses diabetes management focusing on the latest insulin analogues, alternative insulin delivery systems and the artificial pancreas. Intensive insulin therapy with multiple daily injections (MDI) allows better imitation of the physiological rhythm of insulin secretion. Longer-acting, basal insulin analogues provide concomitant improvements in safety, efficacy and variability of glycaemic control, followed by low risks of hypoglycaemia. Continuous subcutaneous insulin infusion (CSII) provides long-term glycaemic control especially in type 1 diabetic patients, while reducing hypoglycaemic episodes and glycaemic variability. Continuous subcutaneous glucose monitoring (CGM) systems provide information on postprandial glucose excursions and nocturnal hypo- and/or hyperglycemias. This information enhances treatment options, provides a useful tool for self-monitoring and allows safer achievement of treatment targets. In the absence of a cure-like pancreas or islets transplants, artificial "closed-loop" systems mimicking the pancreatic activity have been also developed. Individualized treatment plans for insulin initiation and administration mode are critical in achieving target glycaemic levels. Progress in these fields is expected to facilitate and improve the quality of life of diabetic patients.

Implementing smart infusion pumps with dose-error reduction software: real-world experiences.

PubMed

Heron, Claire

2017-04-27

Intravenous (IV) drug administration, especially with 'smart pumps', is complex and susceptible to errors. Although errors can occur at any stage of the IV medication process, most errors occur during reconstitution and administration. Dose-error reduction software (DERS) loaded on to infusion pumps incorporates a drug library with predefined upper and lower drug dose limits and infusion rates, which can reduce IV infusion errors. Although this is an important advance for patient safety at the point of care, uptake is still relatively low. This article discuses the challenges and benefits of implementing DERS in clinical practice as experienced by three UK trusts.

Design and analysis of hydraulic ram water pumping system

NASA Astrophysics Data System (ADS)

Hussin, N. S. M.; Gamil, S. A.; Amin, N. A. M.; Safar, M. J. A.; Majid, M. S. A.; Kazim, M. N. F. M.; Nasir, N. F. M.

2017-10-01

The current pumping system (DC water pump) for agriculture is powered by household electricity, therefore, the cost of electricity will be increased due to the higher electricity consumption. In addition, the water needs to be supplied at different height of trees and different places that are far from the water source. The existing DC water pump can pump the water to 1.5 m height but it cost money for electrical source. The hydraulic ram is a mechanical water pump that suitable used for agriculture purpose. It can be a good substitute for DC water pump in agriculture use. The hydraulic ram water pumping system has ability to pump water using gravitational energy or the kinetic energy through flowing source of water. This project aims to analyze and develop the water ram pump in order to meet the desired delivery head up to 3 meter height with less operation cost. The hydraulic ram is designed using CATIA software. Simulation work has been done using ANSYS CFX software to validate the working concept. There are three design were tested in the experiment study. The best design reached target head of 3 m with 15% efficiency and flow rate of 11.82l/min. The results from this study show that the less diameter of pressure chamber and higher supply head will create higher pressure.

Therapeutics in pediatric diabetes: insulin and non-insulin approaches. Part of a series on Pediatric Pharmacology, guest edited by Gianvincenzo Zuccotti, Emilio Clementi, and Massimo Molteni.

PubMed

Kim, Jongoh; Kim, Se Min; Nguyen, Ha Cam Thuy; Redondo, Maria Jose

2012-01-01

Treatment of pediatric diabetes can be challenging. Strict glucose control can be accompanied by hypoglycemia and weight gain. Recently, there have been many developments in insulin preparations and delivery methods which make insulin levels more close to a physiologic pattern. Newly developed rapid/long acting analogues and delivery devices such as continuous subcutaneous insulin infusion (CSII, insulin pump) may reduce hypoglycemia and improve glycemic control. CSII combined with continuous glucose monitoring can achieve even better glycemic control. The closed-loop system is rapidly evolving and an artificial pancreas will be available in the near future. It is now recognized that several hormones other than insulin such as glucagon, amylin, and incretins contribute to glucose homeostasis. The role of co-adjuncts such as metformin, amylin analogues, and incretin based therapy is now emerging. Immunotherapy in a high risk population or patients in the early phase of type 1 diabetes may prevent further destruction of pancreatic β cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

Psychology, technology, and diabetes management.

PubMed

Gonder-Frederick, Linda A; Shepard, Jaclyn A; Grabman, Jesse H; Ritterband, Lee M

2016-10-01

Use of technology in diabetes management is rapidly advancing and has the potential to help individuals with diabetes achieve optimal glycemic control. Over the past 40 years, several devices have been developed and refined, including the blood glucose meter, insulin pump, and continuous glucose monitor. When used in tandem, the insulin pump and continuous glucose monitor have prompted the Artificial Pancreas initiative, aimed at developing control system for fully automating glucose monitoring and insulin delivery. In addition to devices, modern technology, such as the Internet and mobile phone applications, have been used to promote patient education, support, and intervention to address the behavioral and emotional challenges of diabetes management. These state-of-the-art technologies not only have the potential to improve clinical outcomes, but there are possible psychological benefits, such as improved quality of life, as well. However, practical and psychosocial limitations related to advanced technology exist and, in the context of several technology-related theoretical frameworks, can influence patient adoption and continued use. It is essential for future diabetes technology research to address these barriers given that the clinical benefits appear to largely depend on patient engagement and consistence of technology use. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A method for gear fatigue life prediction considering the internal flow field of the gear pump

NASA Astrophysics Data System (ADS)

Shen, Haidong; Li, Zhiqiang; Qi, Lele; Qiao, Liang

2018-01-01

Gear pump is the most widely used volume type hydraulic pump, and it is the main power source of the hydraulic system. Its performance is influenced by many factors, such as working environment, maintenance, fluid pressure and so on. It is different from the gear transmission system, the internal flow field of gear pump has a greater impact on the gear life, therefore it needs to consider the internal hydraulic system when predicting the gear fatigue life. In this paper, a certain aircraft gear pump as the research object, aim at the typical failure forms, gear contact fatigue, of gear pump, proposing the prediction method based on the virtual simulation. The method use CFD (Computational fluid dynamics) software to analyze pressure distribution of internal flow field of the gear pump, and constructed the unidirectional flow-solid coupling model of gear to acquire the contact stress of tooth surface on Ansys workbench software. Finally, employing nominal stress method and Miner cumulative damage theory to calculated the gear contact fatigue life based on modified material P-S-N curve. Engineering practice show that the method is feasible and efficient.

Classroom attention in children with type 1 diabetes mellitus: the effect of stabilizing serum glucose.

PubMed

Daley, Kelly B; Wodrich, David L; Hasan, Khalid

2006-02-01

To determine whether stabilizing serum glucose, via introduction of an insulin pump, improves classroom attention among children with type-1 diabetes mellitus. Four boys having type-1 diabetes mellitus with unstable serum glucose were observed in their classroom for 10 baseline days. An insulin pump was placed and serum glucose stabilized, and they were then observed again for 10 days. A modified multiple baseline design was used to determine if improved on-task and off-task behavior was associated with better glycemic control. Rating scales and a laboratory measure of attention, measures of secondary interest, were also administered before and after pump introduction, and potential improvement in individuals' scores was evaluated. All boys had apparent improvement in on-task and off-task behavior as observed in their classrooms. Improvements were substantial, averaging 20% in on-task behavior and 34% in off-task behavior. However, no changes were detected on rating scales or laboratory measures. This study offers preliminary evidence that stabilizing serum glucose improves classroom attention, although the effect was detected only by observation of classroom behavior using highly structured techniques. Consequently, use of direct observation techniques may be important in studying the effects of chronic illness on classroom functioning.

Reexamining the Hypoglycemia Fear Survey for Parents of Young Children in a Sample of Children Using Insulin Pumps

PubMed Central

Noser, Amy E.; Clements, Mark A.; Dolan, Lawrence M.; Powers, Scott W.

2017-01-01

Abstract Background: We update the psychometric properties of the Hypoglycemia Fear Survey-Parents of Young Children (HFS-PYC), a 26-item measure of parents' hypoglycemia fear for young children using an insulin pump. Methods: We combined three similar datasets for the analyses. The data analyzed included parents' responses to the HFS-PYC and a demographic form. For a subset of children (n = 91), we also analyzed self-monitoring of blood glucose data. We used confirmatory factor analysis (CFA) to confirm the measure's original factor structure. Additional analyses examined reliability and validity of a revised HFS-PYC for parents of young children using pumps. Results: We analyzed data from 116 parents (93% mothers). Mean child age and HbA1c were 5.2 ± 1.3 years and 8.2% ± 1.1%, respectively. CFA identified a 22-item two-factor solution (χ2 (208, n = 116) = 368.688, P < 0.001, root mean square error of approximation = 0.08, comparative fit index = 0.94, and Tucker-Lewis index = 0.93) with factors corresponding to the original subscales: worry and behavior. The revised subscales demonstrated at least adequate internal consistency (Cronbach's alpha >0.65). Correlations revealed significant negative associations between current HFS-PYC worry scores and children's mean daily blood glucose and percent of very high glucose levels per day, suggesting less fear among parents of young children with elevated glycemic levels. In addition, there was a positive association with the percent of glucose levels in target, suggesting greater hypoglycemia fear among parents of children who have better control. Conclusions: Results provide preliminary evidence for the reliability and validity of a reduced 22-item HFS-PYC for parents of children using insulin pumps. PMID:28118046

Accuracy of a Fourth-Generation Subcutaneous Continuous Glucose Sensor

PubMed Central

Garg, Satish K.; Brazg, Ronald; Bode, Bruce W.; Bailey, Timothy S.; Slover, Robert H.; Sullivan, Ashley; Huang, Suiying; Shin, John; Lee, Scott W.; Kaufman, Francine R.

2017-01-01

Abstract Background: This study evaluated the accuracy and performance of a fourth-generation subcutaneous glucose sensor (Guardian™ Sensor 3) in the abdomen and arm. Methods: Eighty-eight subjects (14–75 years of age, mean ± standard deviation [SD] of 42.0 ± 19.1 years) with type 1 or type 2 diabetes participated in the study. Subjects wore two sensors in the abdomen that were paired with either a MiniMed™ 640G insulin pump, or an iPhone® or iPod® touch® running a glucose monitoring mobile application (Guardian Connect system) and a third sensor in the arm, which was connected to a glucose sensor recorder (GSR). Subjects were also asked to undergo in-clinic visits of 12–14 h on study days 1, 3, and 7 for frequent blood glucose sample testing using a Yellow Springs Instrument (YSI) reference. Results: The overall mean absolute relative difference (MARD ± SD) between abdomen sensor glucose (SG) and YSI reference values was 9.6% ± 9.0% and 9.4% ± 9.8% for the MiniMed 640G insulin pump and Guardian Connect system, respectively; and 8.7% ± 8.0% between arm SG and YSI reference values. The percentage of SG values within 20% agreement of the YSI reference value (for YSI >80 mg/dL) was 90.7% with the MiniMed 640G insulin pump, 91.8% with the Guardian Connect system, and 93.1% for GSR-connected arm sensors. Mean functional sensor life, when calibrating 3–4 times/day, was 145.9 ± 39.3 h for sensors paired with the MiniMed 640G insulin pump, 146.1 ± 41.6 h for sensors paired with the Guardian Connect system, and 147.6 ± 40.4 h for sensors connected to the GSR. Responses to survey questions regarding sensor comfort and ease of use were favorable. Conclusions: The Guardian Sensor 3 glucose sensor, whether located in abdomen or the arm, provided accurate glucose readings when compared with the YSI reference and demonstrated functional life commensurate with the intended 7-day use. ClinicalTrials.gov: NCT02246582 PMID:28700272

Accuracy of a Fourth-Generation Subcutaneous Continuous Glucose Sensor.

PubMed

Christiansen, Mark P; Garg, Satish K; Brazg, Ronald; Bode, Bruce W; Bailey, Timothy S; Slover, Robert H; Sullivan, Ashley; Huang, Suiying; Shin, John; Lee, Scott W; Kaufman, Francine R

2017-08-01

This study evaluated the accuracy and performance of a fourth-generation subcutaneous glucose sensor (Guardian ™ Sensor 3) in the abdomen and arm. Eighty-eight subjects (14-75 years of age, mean ± standard deviation [SD] of 42.0 ± 19.1 years) with type 1 or type 2 diabetes participated in the study. Subjects wore two sensors in the abdomen that were paired with either a MiniMed ™ 640G insulin pump, or an iPhone ® or iPod ® touch ® running a glucose monitoring mobile application (Guardian Connect system) and a third sensor in the arm, which was connected to a glucose sensor recorder (GSR). Subjects were also asked to undergo in-clinic visits of 12-14 h on study days 1, 3, and 7 for frequent blood glucose sample testing using a Yellow Springs Instrument (YSI) reference. The overall mean absolute relative difference (MARD ± SD) between abdomen sensor glucose (SG) and YSI reference values was 9.6% ± 9.0% and 9.4% ± 9.8% for the MiniMed 640G insulin pump and Guardian Connect system, respectively; and 8.7% ± 8.0% between arm SG and YSI reference values. The percentage of SG values within 20% agreement of the YSI reference value (for YSI >80 mg/dL) was 90.7% with the MiniMed 640G insulin pump, 91.8% with the Guardian Connect system, and 93.1% for GSR-connected arm sensors. Mean functional sensor life, when calibrating 3-4 times/day, was 145.9 ± 39.3 h for sensors paired with the MiniMed 640G insulin pump, 146.1 ± 41.6 h for sensors paired with the Guardian Connect system, and 147.6 ± 40.4 h for sensors connected to the GSR. Responses to survey questions regarding sensor comfort and ease of use were favorable. The Guardian Sensor 3 glucose sensor, whether located in abdomen or the arm, provided accurate glucose readings when compared with the YSI reference and demonstrated functional life commensurate with the intended 7-day use. ClinicalTrials.gov : NCT02246582.

Use of diabetes data management software reports by health care providers, patients with diabetes, and caregivers improves accuracy and efficiency of data analysis and interpretation compared with traditional logbook data: first results of the Accu-Chek Connect Reports Utility and Efficiency Study (ACCRUES).

PubMed

Hinnen, Deborah A; Buskirk, Ann; Lyden, Maureen; Amstutz, Linda; Hunter, Tracy; Parkin, Christopher G; Wagner, Robin

2015-03-01

We assessed users' proficiency and efficiency in identifying and interpreting self-monitored blood glucose (SMBG), insulin, and carbohydrate intake data using data management software reports compared with standard logbooks. This prospective, self-controlled, randomized study enrolled insulin-treated patients with diabetes (PWDs) (continuous subcutaneous insulin infusion [CSII] and multiple daily insulin injection [MDI] therapy), patient caregivers [CGVs]) and health care providers (HCPs) who were naïve to diabetes data management computer software. Six paired clinical cases (3 CSII, 3 MDI) and associated multiple-choice questions/answers were reviewed by diabetes specialists and presented to participants via a web portal in both software report (SR) and traditional logbook (TL) formats. Participant response time and accuracy were documented and assessed. Participants completed a preference questionnaire at study completion. All participants (54 PWDs, 24 CGVs, 33 HCPs) completed the cases. Participants achieved greater accuracy (assessed by percentage of accurate answers) using the SR versus TL formats: PWDs, 80.3 (13.2)% versus 63.7 (15.0)%, P < .0001; CGVs, 84.6 (8.9)% versus 63.6 (14.4)%, P < .0001; HCPs, 89.5 (8.0)% versus 66.4 (12.3)%, P < .0001. Participants spent less time (minutes) with each case using the SR versus TL formats: PWDs, 8.6 (4.3) versus 19.9 (12.2), P < .0001; CGVs, 7.0 (3.5) versus 15.5 (11.8), P = .0005; HCPs, 6.7 (2.9) versus 16.0 (12.0), P < .0001. The majority of participants preferred using the software reports versus logbook data. Use of the Accu-Chek Connect Online software reports enabled PWDs, CGVs, and HCPs, naïve to diabetes data management software, to identify and utilize key diabetes information with significantly greater accuracy and efficiency compared with traditional logbook information. Use of SRs was preferred over logbooks. © 2014 Diabetes Technology Society.

Sleep duration and its impact on adherence in adolescents with type 1 diabetes mellitus.

PubMed

McDonough, Ryan J; Clements, Mark A; DeLurgio, Stephen A; Patton, Susana R

2017-06-01

Adherence to the type 1 diabetes (T1D) regimen, while predictive of glycemic control, decreases during adolescence. For adolescents, attaining adequate sleep is an additional challenge. This study evaluates the impact of sleep on adherence in teens with T1D. Forty-five adolescents aged 12-18 yr, with T1D for at least 6 months while on insulin pump therapy. Adolescents logged their sleep on a written diary for 2 wk. Corresponding insulin pump/glucometer downloads as well as sleep habit questionnaires were also obtained. Data from 20 girls and 25 boys, with a mean age of 15 ± 1.6 yr and mean glycated hemoglobin of 8.7 ± 1.1% (72 mmol/mol), were analyzed. Overall, average sleep was 8.6 ± 0.9 h per night. Sleep durations were compared to the next day's frequency of self-monitored blood glucose (SMBG) and total daily insulin bolus frequency. Associations were found between sleep duration and youths' SMBG and insulin bolus frequencies (p < 0.03 and p < 0.001, respectively). Specifically, a 15- and 20-min increase in sleep was associated with one additional SMBG check and one additional insulin bolus, respectively. Analyses suggest an associated increase in T1D self-management behaviors in youths with increased sleep duration. These findings highlight the importance of assessing sleep in clinical practice, and encourage further research to examine effective strategies to address sleep hygiene as part of routine diabetes management. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Prevention of Hypoglycemia With Predictive Low Glucose Insulin Suspension in Children With Type 1 Diabetes: A Randomized Controlled Trial.

PubMed

Battelino, Tadej; Nimri, Revital; Dovc, Klemen; Phillip, Moshe; Bratina, Natasa

2017-06-01

To investigate whether predictive low glucose management (PLGM) of the MiniMed 640G system significantly reduces the rate of hypoglycemia compared with the sensor-augmented insulin pump in children with type 1 diabetes. This randomized, two-arm, parallel, controlled, two-center open-label study included 100 children and adolescents with type 1 diabetes and glycated hemoglobin A 1c ≤10% (≤86 mmol/mol) and using continuous subcutaneous insulin infusion. Patients were randomly assigned to either an intervention group with PLGM features enabled (PLGM ON) or a control group (PLGM OFF), in a 1:1 ratio, all using the same type of sensor-augmented insulin pump. The primary end point was the number of hypoglycemic events below 65 mg/dL (3.6 mmol/L), based on sensor glucose readings, during a 14-day study treatment. The analysis was performed by intention to treat for all randomized patients. The number of hypoglycemic events below 65 mg/dL (3.6 mmol/L) was significantly smaller in the PLGM ON compared with the PLGM OFF group (mean ± SD 4.4 ± 4.5 and 7.4 ± 6.3, respectively; P = 0.008). This was also true when calculated separately for night ( P = 0.025) and day ( P = 0.022). No severe hypoglycemic events occurred; however, there was a significant increase in time spent above 140 mg/dL (7.8 mmol/L) in the PLGM ON group ( P = 0.0165). The PLGM insulin suspension was associated with a significantly reduced number of hypoglycemic events. Although this was achieved at the expense of increased time in moderate hyperglycemia, there were no serious adverse effects in young patients with type 1 diabetes. © 2017 by the American Diabetes Association.

An observational 7-year study of continuous subcutaneous insulin infusion for the treatment of type 1 diabetes mellitus.

PubMed

Papargyri, Panagiota; Ojeda Rodríguez, Sylvie; Corrales Hernández, Juan José; Mories Álvarez, María Teresa; Recio Córdova, José María; Delgado Gómez, Manuel; Sánchez Marcos, Ana Isabel; Iglesias López, Rosa Ana; Herrero Ruiz, Ana; Beaulieu Oriol, Myriam; Miralles García, José Manuel

2014-03-01

This work reports the experience with use of continuous subcutaneous insulin infusion (CSII) in 112 type 1 diabetic patients followed up for 7 years and previously treated with multiple daily insulin injections (MDII). A retrospective, observational study in 112 patients with diabetes mellitus treated with CSII from 2005 to 2012, previously treated with MDII and receiving individualized diabetic education with a specific protocol. Variables analyzed included: prevalence of the different indications of pump treatment; mean annual HbA1c and fructosamine values before and after CSII treatment; and hypoglycemia frequency and symptoms. The most common reason for pump treatment was brittle diabetes (74.1%), followed by frequent or severe hypoglycemia or hypoglycemia unawareness (44.6%). Other indications were irregular food intake times for professional reasons (20.2%), dawn phenomenon (15.7%), pregnancy (12.3%), requirement of very low insulin doses (8.9%), and gestational diabetes (0.9%). HbA1c decreased by between 0.6% and 0.9%, and fructosamine by between 5.1% and 12.26%. Nine percent of patients experienced hypoglycemia weekly, 24% every two weeks, and 48% monthly. No hypoglycemia occurred in 19% of patients. Only 10% had neuroglycopenic symptoms. Hypoglycemia unawareness was found in 21%. Hypoglycemia was more common at treatment start, and its frequency rapidly decreased thereafter. CSII therapy provides a better glycemic control than MDII treatment. Specific patient training and fine adjustment of insulin infusion doses are required to prevent hypoglycemic episodes, which are the most common complications, mainly at the start of treatment. Copyright © 2013 SEEN. Published by Elsevier Espana. All rights reserved.

Overweight, obesity and features of metabolic syndrome in children with diabetes treated with insulin pump therapy.

PubMed

Łuczyński, Włodzimierz; Szypowska, Agnieszka; Głowińska-Olszewska, Barbara; Bossowski, Artur

2011-07-01

There has been no specific evaluation of atherogenic risk factors in children with type 1 diabetes mellitus (T1DM) treated with continuous subcutaneous insulin infusion (CSII). We, therefore, studied the prevalence of overweight/obesity and metabolic syndrome among these patients. Five hundred children with T1DM treated with CSII and multiple daily insulin (MDI) regimen were included in the study. Anthropometric data/physical examination, data concerning diabetes, and a lipid profile were assessed in this group, and compared with respect to treatment method (CSII vs. MDI). Almost one-third (30.2%) of the children were overweight/obese. The body mass index (BMI) values at the time of the present evaluation were significantly higher in comparison with the BMI values 3-6 months after the diagnosis. Dyslipidemia was recognized in 51.6%, hypertension in 4.8%, and the metabolic syndrome in 3.2%. of the subjects. The overweight/obese children differed from their normal-weight counterparts with respect to metabolic control, the incidence of hypertension, dyslipidemia, and metabolic syndrome. The girls showed higher prevalence of overweight/obesity and higher BMI values compared to the boys. The children treated with CSII had the same prevalence of overweight/obesity, but a lower incidence of dyslipidemia, and a better metabolic control compared to the children treated with MDI regimen. Our study shows a high prevalence of overweight/obesity and dyslipidemia in children with T1DM including those treated with an insulin pump.

Accessibility of insulin pumps for blind and visually impaired people.

PubMed

Uslan, Mark M; Burton, Darren M; Chertow, Bruce S; Collins, Ronda

2004-10-01

Continuous subcutaneous insulin infusion using an insulin pump (IP) more closely mimics the normal pancreas than multiple insulin injections. It is an effective, and often a preferred, means of maintaining normal blood glucose levels, but IPs were not designed to be fully accessible to blind or visually impaired people. This study will identify accessibility issues related to the design of IPs and focus on the key improvements required in the user interface to provide access for people who are blind or visually impaired. IPs that are commercially available were evaluated, and features and functions such as operating procedures, user interface design, and user manuals were tabulated and analyzed. Potential failures and design priorities were identified through a Failure Modes and Effects Analysis (FMEA). Although the IPs do provide some limited audio output, in general, it was found to be of minimal use to people who are blind or visually impaired. None of the IPs uses high-contrast displays with consistently large fonts preferred by people who are visually impaired. User manuals were also found to be of minimal use. Results of the FMEA emphasize the need to focus design improvements on communicating and verifying information so that errors and failures can be detected and corrected. The most important recommendation for future IP development is speech output capability, which, more than any other improvement, would break down accessibility barriers and allow blind and visually impaired people to take advantage of the benefits of IP technology.

Software defined photon counting system for time resolved x-ray experiments.

PubMed

Acremann, Y; Chembrolu, V; Strachan, J P; Tyliszczak, T; Stöhr, J

2007-01-01

The time structure of synchrotron radiation allows time resolved experiments with sub-100 ps temporal resolution using a pump-probe approach. However, the relaxation time of the samples may require a lower repetition rate of the pump pulse compared to the full repetition rate of the x-ray pulses from the synchrotron. The use of only the x-ray pulse immediately following the pump pulse is not efficient and often requires special operation modes where only a few buckets of the storage ring are filled. We designed a novel software defined photon counting system that allows to implement a variety of pump-probe schemes at the full repetition rate. The high number of photon counters allows to detect the response of the sample at multiple time delays simultaneously, thus improving the efficiency of the experiment. The system has been successfully applied to time resolved scanning transmission x-ray microscopy. However, this technique is applicable more generally.

Keeping Track of Your Blood Sugar

MedlinePlus

... after you join a sports team at school. People who use an insulin pump or who follow a plan ... Editorial Policy Permissions Guidelines Privacy Policy & Terms of ... is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © ...

Assessing sensor accuracy for non-adjunct use of continuous glucose monitoring.

PubMed

Kovatchev, Boris P; Patek, Stephen D; Ortiz, Edward Andrew; Breton, Marc D

2015-03-01

The level of continuous glucose monitoring (CGM) accuracy needed for insulin dosing using sensor values (i.e., the level of accuracy permitting non-adjunct CGM use) is a topic of ongoing debate. Assessment of this level in clinical experiments is virtually impossible because the magnitude of CGM errors cannot be manipulated and related prospectively to clinical outcomes. A combination of archival data (parallel CGM, insulin pump, self-monitoring of blood glucose [SMBG] records, and meals for 56 pump users with type 1 diabetes) and in silico experiments was used to "replay" real-life treatment scenarios and relate sensor error to glycemic outcomes. Nominal blood glucose (BG) traces were extracted using a mathematical model, yielding 2,082 BG segments each initiated by insulin bolus and confirmed by SMBG. These segments were replayed at seven sensor accuracy levels (mean absolute relative differences [MARDs] of 3-22%) testing six scenarios: insulin dosing using sensor values, threshold, and predictive alarms, each without or with considering CGM trend arrows. In all six scenarios, the occurrence of hypoglycemia (frequency of BG levels ≤50 mg/dL and BG levels ≤39 mg/dL) increased with sensor error, displaying an abrupt slope change at MARD =10%. Similarly, hyperglycemia (frequency of BG levels ≥250 mg/dL and BG levels ≥400 mg/dL) increased and displayed an abrupt slope change at MARD=10%. When added to insulin dosing decisions, information from CGM trend arrows, threshold, and predictive alarms resulted in improvement in average glycemia by 1.86, 8.17, and 8.88 mg/dL, respectively. Using CGM for insulin dosing decisions is feasible below a certain level of sensor error, estimated in silico at MARD=10%. In our experiments, further accuracy improvement did not contribute substantively to better glycemic outcomes.

Reduction in duration of hypoglycemia by automatic suspension of insulin delivery: the in-clinic ASPIRE study.

PubMed

Garg, Satish; Brazg, Ronald L; Bailey, Timothy S; Buckingham, Bruce A; Slover, Robert H; Klonoff, David C; Shin, John; Welsh, John B; Kaufman, Francine R

2012-03-01

The efficacy of automatic suspension of insulin delivery in induced hypoglycemia among subjects with type 1 diabetes was evaluated. In this randomized crossover study, subjects used a sensor-augmented insulin pump system with a low glucose suspend (LGS) feature that automatically stops insulin delivery for 2 h following a sensor glucose (SG) value ≤70 mg/dL. Subjects fasted overnight and exercised until their plasma glucose (measured with the YSI 2300 STAT Plus™ glucose and lactate analyzer [YSI Life Sciences, Yellow Springs, OH]) value reached ≤85 mg/dL on different occasions separated by washout periods lasting 3-10 days. Exercise sessions were done with the LGS feature turned on (LGS-On) or with continued insulin delivery regardless of SG value (LGS-Off). The order of LGS-On and LGS-Off sessions was randomly assigned. YSI glucose data were used to compare the duration and severity of hypoglycemia from successful LGS-On and LGS-Off sessions and to estimate the risk of rebound hyperglycemia after pump suspension. Fifty subjects attempted 134 sessions, 98 of which were successful. The mean±SD hypoglycemia duration was less during LGS-On than during LGS-Off sessions (138.5±76.68 vs. 170.7±75.91 min, P=0.006). During LGS-On compared with LGS-Off sessions, mean nadir YSI glucose was higher (59.5±5.72 vs. 57.6±5.69 mg/dL, P=0.015), as was mean end-observation YSI glucose (91.4±41.84 vs. 66.2±13.48 mg/dL, P<0.001). Most (53.2%) end-observation YSI glucose values in LGS-On sessions were in the 70-180 mg/dL range, and none was >250 mg/dL. Automatic suspension of insulin delivery significantly reduced the duration and severity of induced hypoglycemia without causing rebound hyperglycemia.

Assessing Sensor Accuracy for Non-Adjunct Use of Continuous Glucose Monitoring

PubMed Central

Patek, Stephen D.; Ortiz, Edward Andrew; Breton, Marc D.

2015-01-01

Abstract Background: The level of continuous glucose monitoring (CGM) accuracy needed for insulin dosing using sensor values (i.e., the level of accuracy permitting non-adjunct CGM use) is a topic of ongoing debate. Assessment of this level in clinical experiments is virtually impossible because the magnitude of CGM errors cannot be manipulated and related prospectively to clinical outcomes. Materials and Methods: A combination of archival data (parallel CGM, insulin pump, self-monitoring of blood glucose [SMBG] records, and meals for 56 pump users with type 1 diabetes) and in silico experiments was used to “replay” real-life treatment scenarios and relate sensor error to glycemic outcomes. Nominal blood glucose (BG) traces were extracted using a mathematical model, yielding 2,082 BG segments each initiated by insulin bolus and confirmed by SMBG. These segments were replayed at seven sensor accuracy levels (mean absolute relative differences [MARDs] of 3–22%) testing six scenarios: insulin dosing using sensor values, threshold, and predictive alarms, each without or with considering CGM trend arrows. Results: In all six scenarios, the occurrence of hypoglycemia (frequency of BG levels ≤50 mg/dL and BG levels ≤39 mg/dL) increased with sensor error, displaying an abrupt slope change at MARD =10%. Similarly, hyperglycemia (frequency of BG levels ≥250 mg/dL and BG levels ≥400 mg/dL) increased and displayed an abrupt slope change at MARD=10%. When added to insulin dosing decisions, information from CGM trend arrows, threshold, and predictive alarms resulted in improvement in average glycemia by 1.86, 8.17, and 8.88 mg/dL, respectively. Conclusions: Using CGM for insulin dosing decisions is feasible below a certain level of sensor error, estimated in silico at MARD=10%. In our experiments, further accuracy improvement did not contribute substantively to better glycemic outcomes. PMID:25436913

Cost-effectiveness of sensor-augmented pump therapy in two different patient populations with type 1 diabetes in Italy.

PubMed

Nicolucci, A; Rossi, M C; D'Ostilio, D; Delbaere, A; de Portu, S; Roze, S

2018-07-01

Sensor-augmented pump therapy (SAP) combines real time continuous glucose monitoring (CGM) with Continuous Subcutaneous Insulin Infusion (CSII) and provides additional benefits beyond those provided by CSII alone. SAP with automated insulin suspension provides early warning of the onset of hyperglycemia and hypoglycemia and has the functionality to suspend insulin delivery if sensor glucose levels are predicted to fall below a predefined threshold. Aim of this study was to assess the cost-effectiveness of SAP with automated insulin suspension versus CSII alone in type 1 diabetes. Cost-effectiveness analysis was performed using the CORE Diabetes Model. The analysis was performed in two different cohorts: one with high baseline HbA1c and one at elevated risk for hypoglycemic events. Clinical input data were sourced from published data. The analysis was conducted from a societal perspective over a lifetime time horizon; costs and clinical outcomes were discounted at 3% per year. In patients with poor glycemic control, SAP with automated insulin suspension resulted in improved discounted quality-adjusted life expectancy (QALY) versus CSII (12.44 QALYs vs. 10.99 QALYs) but higher mean total lifetime costs (€324,991 vs. €259,852), resulting in an incremental cost effectiveness ratio (ICER) of €44,982 per QALY gained. In patients at elevated risk for hypoglycemia, the ICER was €33,692 per QALY gained for SAP versus CSII. In Italy, the use of SAP with automated insulin suspension is associated with projected improvements in outcomes as compared to CSII. These benefits translate into an ICER usually considered as good value for money, particularly in patients at elevated risk of hypoglycemia. Copyright © 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

The PILGRIM study: in silico modeling of a predictive low glucose management system and feasibility in youth with type 1 diabetes during exercise.

PubMed

Danne, Thomas; Tsioli, Christiana; Kordonouri, Olga; Blaesig, Sarah; Remus, Kerstin; Roy, Anirban; Keenan, Barry; Lee, Scott W; Kaufman, Francine R

2014-06-01

Predictive low glucose management (PLGM) may help prevent hypoglycemia by stopping insulin pump delivery based on predicted sensor glucose values. Hypoglycemic challenges were simulated using the Food and Drug Administration-accepted glucose simulator with 100 virtual patients. PLGM was then tested with a system composed of a Paradigm(®) insulin pump (Medtronic, Northridge, CA), an Enlite™ glucose sensor (Medtronic), and a BlackBerry(®) (Waterloo, ON, Canada)-based controller. Subjects (n=22) on continuous subcutaneous insulin infusion (five females, 17 males; median [range] age, 15 [range, 14-20] years; median [range] diabetes duration, 7 [2-14] years; median [range] glycated hemoglobin, 8.0% [6.7-10.4%]) exercised until the PLGM system suspended insulin delivery or until the reference blood glucose value (HemoCue(®); HemoCue GmbH, Großostheim, Germany) reached the predictive suspension threshold setting. PLGM reduced hypoglycemia (<70 mg/dL) in silico by 26.7% compared with no insulin suspension, as opposed to a 5.3% reduction in hypoglycemia with use of low glucose suspend (LGS). The median duration of hypoglycemia (time spent <70 mg/dL) with PLGM was significantly less than with LGS (58 min vs. 101 min, respectively; P<0.001). In the clinical trial the hypoglycemic threshold during exercise was reached in 73% of the patients, and hypoglycemia was prevented in 80% of the successful experiments. The mean (±SD) sensor glucose at predictive suspension was 92±7 mg/dL, resulting in a postsuspension nadir (by HemoCue) of 77±22 mg/dL. The suspension lasted for 90±35 (range, 30-120) min, resulting in a sensor glucose level at insulin resumption of 97±19 mg/dL. In silico modeling and early feasibility data demonstrate that PLGM may further reduce the severity of hypoglycemia beyond that already established for algorithms that use a threshold-based suspension.

Continuous subcutaneous insulin infusion in diabetes: patient populations, safety, efficacy, and pharmacoeconomics

PubMed Central

Battelino, Tadej; Danne, Thomas; Hovorka, Roman; Jarosz‐Chobot, Przemyslawa; Renard, Eric

2015-01-01

Summary The level of glycaemic control necessary to achieve optimal short‐term and long‐term outcomes in subjects with type 1 diabetes mellitus (T1DM) typically requires intensified insulin therapy using multiple daily injections or continuous subcutaneous insulin infusion. For continuous subcutaneous insulin infusion, the insulins of choice are the rapid‐acting insulin analogues, insulin aspart, insulin lispro and insulin glulisine. The advantages of continuous subcutaneous insulin infusion over multiple daily injections in adult and paediatric populations with T1DM include superior glycaemic control, lower insulin requirements and better health‐related quality of life/patient satisfaction. An association between continuous subcutaneous insulin infusion and reduced hypoglycaemic risk is more consistent in children/adolescents than in adults. The use of continuous subcutaneous insulin infusion is widely recommended in both adult and paediatric T1DM populations but is limited in pregnant patients and those with type 2 diabetes mellitus. All available rapid‐acting insulin analogues are approved for use in adult, paediatric and pregnant populations. However, minimum patient age varies (insulin lispro: no minimum; insulin aspart: ≥2 years; insulin glulisine: ≥6 years) and experience in pregnancy ranges from extensive (insulin aspart, insulin lispro) to limited (insulin glulisine). Although more expensive than multiple daily injections, continuous subcutaneous insulin infusion is cost‐effective in selected patient groups. This comprehensive review focuses on the European situation and summarises evidence for the efficacy and safety of continuous subcutaneous insulin infusion, particularly when used with rapid‐acting insulin analogues, in adult, paediatric and pregnant populations. The review also discusses relevant European guidelines; reviews issues that surround use of this technology; summarises the effects of continuous subcutaneous insulin infusion on patients' health‐related quality of life; reviews relevant pharmacoeconomic data; and discusses recent advances in pump technology, including the development of closed‐loop ‘artificial pancreas’ systems. © 2015 The Authors. Diabetes/Metabolism Research and Reviews Published by John Wiley & Sons Ltd. PMID:25865292

Continuous quality improvement using intelligent infusion pump data analysis.

PubMed

Breland, Burnis D

2010-09-01

The use of continuous quality-improvement (CQI) processes in the implementation of intelligent infusion pumps in a community teaching hospital is described. After the decision was made to implement intelligent i.v. infusion pumps in a 413-bed, community teaching hospital, drug libraries for use in the safety software had to be created. Before drug libraries could be created, it was necessary to determine the epidemiology of medication use in various clinical care areas. Standardization of medication administration was performed through the CQI process, using practical knowledge of clinicians at the bedside and evidence-based drug safety parameters in the scientific literature. Post-implementation, CQI allowed refinement of clinically important safety limits while minimizing inappropriate, meaningless soft limit alerts on a few select agents. Assigning individual clinical care areas (CCAs) to individual patient care units facilitated customization of drug libraries and identification of specific CCA compliance concerns. Between June 2007 and June 2008, there were seven library updates. These involved drug additions and deletions, customization of individual CCAs, and alterations of limits. Overall compliance with safety software use rose over time, from 33% in November 2006 to over 98% in December 2009. Many potentially clinically significant dosing errors were intercepted by the safety software, prompting edits by end users. Only 4-6% of soft limit alerts resulted in edits. Compliance rates for use of infusion pump safety software varied among CCAs over time. Education, auditing, and refinement of drug libraries led to improved compliance in most CCAs.

Hypoglycemia and blood glucose fluctuations in the application of a sensor-augmented insulin pump.

PubMed

Luo, Pei; Cheng, Qianpeng; Chen, Bin; Li, Yang; Wu, Jinxiao; Zhang, Xingguang; Jiao, Xiumin; Zhao, Jing; Lv, Xiaofeng

2013-12-01

The purpose of this study was to understand the effect of sensor-augmented insulin pump (SAP) use on hypoglycemia and blood glucose (BG) fluctuations. Sixty patients with type 2 diabetes mellitus were randomly assigned to three groups of treatment with SAP, continuous subcutaneous insulin infusion (CSII), or multiple daily injection (MDI) therapy for 6 days. Parameters of glycemic control that were determined included mean BG concentration (MBG), SD of BG (SDBG), mean amplitude of glycemic excursions (MAGE), absolute means of daily differences (MODD), 24-h area under the curve at 10 h (AUC10), 24-h area under the curve at 3.9 h (AUC3.9), and Low Blood Glucose Index (LBGI). No significant differences were observed among the three groups in terms of MBG, SDBG, MAGE, or MODD at the beginning of treatment. The MBG, SDBG, MAGE, MODD, and total AUC10 of the SAP group improved over the 4 days of the intervention compared with the CSII and MDI groups; however, no significant differences were observed among the three groups in terms of total AUC3.9 and LBGI. Compared with CSII and MDI therapy, SAP therapy was able to rapidly lower mean BG and reduce BG level fluctuations with no increased risks of hypoglycemia.

Continuous glucose monitoring: A review of the technology and clinical use.

PubMed

Klonoff, David C; Ahn, David; Drincic, Andjela

2017-11-01

Continuous glucose monitoring (CGM) is an increasingly adopted technology for insulin-requiring patients that provides insights into glycemic fluctuations. CGM can assist patients in managing their diabetes with lifestyle and medication adjustments. This article provides an overview of the technical and clinical features of CGM based on a review of articles in PubMed on CGM from 1999 through January 31, 2017. A detailed description is presented of three professional (retrospective), three personal (real-time) continuous glucose monitors, and three sensor integrated pumps (consisting of a sensor and pump that communicate with each other to determine an optimal insulin dose and adjust the delivery of insulin) that are currently available in United States. We have reviewed outpatient CGM outcomes, focusing on hemoglobin A1c (A1C), hypoglycemia, and quality of life. Issues affecting accuracy, detection of glycemic variability, strategies for optimal use, as well as cybersecurity and future directions for sensor design and use are discussed. In conclusion, CGM is an important tool for monitoring diabetes that has been shown to improve outcomes in patients with type 1 diabetes mellitus. Given currently available data and technological developments, we believe that with appropriate patient education, CGM can also be considered for other patient populations. Copyright © 2017 Elsevier B.V. All rights reserved.

One-year efficacy and safety of Web-based follow-up using cellular phone in type 1 diabetic patients under insulin pump therapy: the PumpNet study.

PubMed

Benhamou, P-Y; Melki, V; Boizel, R; Perreal, F; Quesada, J-L; Bessieres-Lacombe, S; Bosson, J-L; Halimi, S; Hanaire, H

2007-06-01

Conventional follow-up of type 1 diabetic patients treated with continuous subcutaneous insulin infusion (CSII) was compared with intensive coaching using the Web and the cellular phone network for retrospective data transmission and short message service (SMS). Thirty poorly controlled patients (HbA1c 7.5-10%) were enrolled in a bicenter, open-label, randomized, 12-month, two-period, crossover study. After a 1-month run-in period, 15 patients were randomly assigned to receive weekly medical support through SMS based upon weekly review of glucose values, while 15 patients continued to download self-monitored blood glucose (SMBG) values on a weekly basis without receiving SMS. After 6 months, patients crossed over to the alternate sequence for 6 additional months. Visits at the clinic were maintained every 3 months. Patients with long-standing inadequately controlled diabetes (24 +/- 13 years) were included. A non-significant trend to reduction in HbA(1c) (-0.25+/-0.94%, P<0.10) and mean glucose values (-9.2+/-25 mg/dl, P=0.06) during the 6-month SMS sequence was observed as compared with the no-SMS period. No safety issue (hypoglycemia, glucose variability) was reported. Adherence to SMBG was not affected by the trial. Quality of life analysis suggests a significant improvement in DQOL global score, as well as the DQOL satisfaction with life subscale, during the SMS sequence. Long-term telemedical follow-up of insulin pump-treated patients using a cellular phone-, SMS- and Web-based platform is feasible, safe, does not alter quality of life and associated with a trend toward improved metabolic control.

Cost-Effectiveness of Sensor-Augmented Pump Therapy with Low Glucose Suspend Versus Standard Insulin Pump Therapy in Two Different Patient Populations with Type 1 Diabetes in France.

PubMed

Roze, Stéphane; Smith-Palmer, Jayne; Valentine, William; Payet, Vincent; de Portu, Simona; Papo, Natalie; Cucherat, Michel; Hanaire, Helene

2016-02-01

Sensor-augmented pump therapy (SAP) provides a useful adjunct relative to continuous subcutaneous insulin infusion (CSII) alone. It can provide early warning of the onset of hyperglycemia and hypoglycemia and has the functionality to suspend insulin delivery if sensor glucose levels fall below a predefined threshold. The aim was to assess the cost-effectiveness of SAP with low glucose suspend (LGS) versus CSII alone in type 1 diabetes. Cost-effectiveness analysis was performed using the CORE Diabetes Model, using published clinical input data. The analysis was performed in two cohorts: one with uncontrolled glycated hemoglobin at baseline and one at elevated risk for hypoglycemic events. The analysis was conducted from a healthcare payer perspective over a lifetime time horizon; future costs and clinical outcomes were discounted at 4% per annum. In patients with uncontrolled glycated hemoglobin at baseline, SAP + LGS resulted in improved discounted quality-adjusted life expectancy (QALE) versus CSII (10.55 quality-adjusted life-years [QALYs] vs. 9.36 QALYs) but higher mean lifetime direct costs (€84,972 vs. €49,171) resulting in an incremental cost-effectiveness ratio (ICER) of €30,163 per QALY gained. In patients at elevated risk for hypoglycemia, the ICER was €22,005 per QALY gained for SAP + LGS versus CSII as lifetime costs were higher (€88,680 vs. €57,097), but QALE was also higher (18.46 QALYs vs. 18.30 QALYs). In France, projected improvements in outcomes with SAP + LGS versus CSII translated into an ICER generally considered as good value for money, particularly in patients who experience frequent and/or problematic hypoglycemic events.

Cost-effectiveness of sensor-augmented pump therapy versus standard insulin pump therapy in patients with type 1 diabetes in Denmark.

PubMed

Roze, S; de Portu, S; Smith-Palmer, J; Delbaere, A; Valentine, W; Ridderstråle, M

2017-06-01

The use of continuous subcutaneous insulin infusion (CSII) in type 1 diabetes (T1D) has increased in recent years. Sensor-augmented pump therapy (SAP) with low glucose suspend (LGS) (allowing temporary suspension of insulin delivery if blood glucose level falls below a pre-defined threshold level) provides additional benefits over CSII alone, but is associated with higher acquisition costs. Therefore, a cost-effectiveness analysis of SAP+LGS versus CSII in patients with T1D was performed. Analyses were performed using the CORE Diabetes Model in two different patient cohorts in Denmark, one with hyperglycemia at baseline and one with increased risk for hypoglycemic events. Clinical input data were sourced from published literature. The analysis was performed over a lifetime time horizon from a societal perspective. Future costs and clinical outcomes were discounted at 3% per annum. In patients who were hyperglycemic at baseline the use of SAP+LGS versus CSII resulted in improved quality-adjusted life expectancy (12.44 versus 10.99 quality-adjusted life years [QALYs]) but higher mean lifetime costs (DKK 2,027,316 versus DKK 1,801,293) leading to an incremental cost-effectiveness ratio (ICER) of DKK 156,082 per QALY gained. For patients at increased risk for hypoglycemic events the ICER for SAP+LGS versus CSII was DKK 89,868 per QALY gained. The ICER for SAP+LGS versus CSII falls below commonly cited willingness-to-pay thresholds. Therefore, in Denmark, the use of SAP+LGS is likely to be considered cost-effective relative to CSII for patients with T1D who are either hyperglycemic, despite CSII use, or who experience frequent severe hypoglycemic events. Copyright © 2017 Elsevier B.V. All rights reserved.

Feeding problems reported by parents of young children with type 1 diabetes on insulin pump therapy and their associations with children's glycemic control.

PubMed

Patton, Susana R; Williams, Laura B; Dolan, Lawrence M; Chen, Ming; Powers, Scott W

2009-11-01

Previous research demonstrated high rates of perceived mealtime behavior problems in families of young children with type 1 diabetes who were managed with conventional therapy. Because of new insulin regimens that offer greater flexibility, reexamination of mealtime behaviors is required. We assessed parent-reported mealtime behaviors in a sample of young children using an insulin pump. An additional aim was to evaluate the associations of two measures of parental feeding behavior with children's glycemic control. Primary caregivers of 31 young children (mean age = 5.0 +/- 1.3 yr) completed the Child Feeding Questionnaire (CFQ) and the Behavioral Pediatric Feeding Assessment Scale (BPFAS). Hemoglobin A1c (HbA1c) was used as a surrogate marker for children's glycemic control. Children had a mean HbA1c of 7.8 +/- 0.64%. Mean CFQ - Restriction and Pressure to Eat scores were 3.1 +/- 0.94 and 2.0 +/- 0.88, respectively (range = 1-5). Mean BPFAS - Parent and Child scores were 16.0 +/- 4.3 (range = 10-50) and 44.9 +/- 9.3 (range = 25-125), respectively. Positive correlations were found between children's HbA1c levels and caregivers' reporting of frequency of child mealtime behavior problems. Caregivers of young children on pump therapy report relatively low rates of mealtime behavior problems. However, correlations with children's HbA1c suggest that parent-child mealtime behaviors continue to relate to children's health outcomes. Research is needed to determine if changing mealtime interactions can improve children's glycemic control; items from the BPFAS and CFQ can offer targets to guide interventions.

[Current status of continuous subcutaneous insulin infusion and continuous glucose monitoring systems in the Community of Madrid].

PubMed

Arranz Martín, Alfonso; Calle Pascual, Alfonso; Del Cañizo Gómez, Francisco Javier; González Albarrán, Olga; Lisbona Gil, Arturo; Botella Serrano, Marta; Pallardo Sánchez, Luis Felipe

2015-04-01

To analyze the available information about continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) systems in the public health care system of the Community of Madrid. A survey consisting of 31 items was sent to the 28 endocrinology department of the Madrid public hospitals. Items focused on CSII and CGM and included patients' registrations, as well as data regarding healthcare, administrative, and logistic aspects. Responses from a total of 20 hospitals where these procedures are used were received from March 2013 to May 2014. Data about pediatric patients were obtained from adult endocrinology departments, except for two hospitals which directly reported the information. A total of 1256 CSII pumps were recorded in the Madrid region, of which 1089 were used by adults, and the remaining 167 by pediatric patients. During 2013, 151 new CSII systems were implanted (12% of the total), while 14 pumps were withdrawn. Availability of human resources (medical assistance) and the number of staff practitioners experienced in management of these systems widely varied between hospitals. Eighty-five percent of hospitals used retrospective CGM systems, and 40% routinely placed them before starting an insulin pump. Thirteen hospitals (65%) used long-term, real-time CGM systems in selected cases (a total of 67 patients). Use of these technologies in diabetes is unequal between public health care hospitals in Madrid, and is still significantly lower as compared to other countries with similar incomes. However, there appears to be a trend to an increase in their use. Copyright © 2014 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Examination of Psychosocial and Physiological Risk for Bulimic Symptoms in Youth With Type 1 Diabetes Transitioning to an Insulin Pump: A Pilot Study.

PubMed

Peterson, Claire M; Young-Hyman, Deborah; Fischer, Sarah; Markowitz, Jessica T; Muir, Andrew B; Laffel, Lori M

2018-01-01

This study tested hypotheses drawn from a risk model positing that psychosocial risk plus disease-related and treatment factors contribute to bulimic symptoms in youth with type 1 diabetes (T1D) transitioning to an insulin pump. The goal of this study was to examine whether disease-related factors, particularly disease- and treatment-based disruption in hunger and satiety, contribute to report of bulimic symptoms in youth with T1D after accounting for psychosocial risk factors. 43 youth (ages 10-17, 54% female) with established T1D were recruited before transition from multiple daily injections to insulin-pump therapy from three tertiary pediatric diabetes centers. Participants completed measures of bulimic symptoms, depressive symptoms dietary restraint, and the Diabetes Treatment and Satiety Scale, a diabetes-specific questionnaire assessing hunger and satiety cues and eating behavior in response to blood glucose levels and treatment. Hierarchical multiple regression was used to assess contributions of psychosocial and disease-based risk to report of bulimic symptoms. After assessing the contributions of body mass index, body image dissatisfaction, and dietary restraint, a significant 2-way interaction emerged between depression and diabetes-related uncontrollable hunger related to bulimic symptoms (β = 1.82, p < .01). In addition to psychosocial risk, disease- and treatment-based hunger and satiety dysregulation appear to be important factors contributing to report of bulimic symptoms in youth with T1D. These preliminary findings have significant treatment implications for bulimic symptoms in youth with T1D. © The Author 2017. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Efficacy and safety of insulin pump treatment in adult T1DM patients--influence of age and social environment.

PubMed

Grzanka, Małgorzata; Matejko, Bartłomiej; Cyganek, Katarzyna; Kozek, Elżbieta; Małecki, Maciej T; Klupa, Tomasz

2012-01-01

Continuous subcutaneous insulin infusion (CSII) via personal insulin pump is a valuable therapeutic tool in T1DM patients. However, adherence to recommended CSII-related behaviours may be of concern to young adults with intensive, variable daily activities (students, young professionals). The aim of this observational study was to estimate treatment outcomes in young adult patients with T1DM, and compare them with older individuals. Overall, 140 adults with T1DM on CSII were examined, divided into 2 subgroups: 77 patients younger than 26 years of age (mean 20.6 years) and 63 older subjects (mean 39.0). We compared the glycaemic control in both groups of T1DM subjects and analyzed treatment attitudes to identify potentially modifiable behaviours influencing the efficacy of the treatment. The younger individuals were characterized by significantly worse treatment outcomes, compared to the older ones: the mean HbA1c levels were 7.6 ± 1.3% and 6.9±1.3% (p=0.00001), while the mean glucose levels based on glucometer downloads were 161±33.6 mg/dL and 136±21.8 mg/dL (p=0.00001), respectively. The frequency of self-monitoring of blood glucose (SMBG) was lower in younger individuals (5.3±2.1 vs. 7.0±2.8 daily, p=0.0005, respectively); they were also less frequently used advanced pump functions, e.g. the bolus calculator (48% vs. 67% users, p=0.0014, respectively). The efficacy of CSII treatment observed in young T1DM adults was worse than in older patients. The reason for this phenomenon remains unclear, it may be due simply to age-dependend behaviours, to social environment, or both.

Donohue syndrome and use of continuous subcutaneous insulin pump therapy.

PubMed

Huggard, Dean; Stack, Tom; Satas, Saulius; Gorman, Clodagh O

2015-10-27

Donohue syndrome is a rare autosomal recessive condition caused by severe loss-of-function mutations in the insulin receptor (INSR) gene. The diagnosis is made on clinical, biochemical and genetic grounds. Mutations are found on chromosome 19p13.2, and code for mutations in the INSR gene. Treatment is challenging and often unsuccessful, and relies on maintaining normoglycaemia and avoiding fasting; in some patients, recombinant human insulin-like growth factor (rhIGF-1) has been trialled. The prognosis is poor, with most babies dying in infancy. Ethically, it is important to consider the benefit versus burden of treatment, the quality of life of the surviving patient and the parents' wishes, when making decisions regarding withholding or withdrawing care. 2015 BMJ Publishing Group Ltd.

Open-Source Syringe Pump Library

PubMed Central

Wijnen, Bas; Hunt, Emily J.; Anzalone, Gerald C.; Pearce, Joshua M.

2014-01-01

This article explores a new open-source method for developing and manufacturing high-quality scientific equipment suitable for use in virtually any laboratory. A syringe pump was designed using freely available open-source computer aided design (CAD) software and manufactured using an open-source RepRap 3-D printer and readily available parts. The design, bill of materials and assembly instructions are globally available to anyone wishing to use them. Details are provided covering the use of the CAD software and the RepRap 3-D printer. The use of an open-source Rasberry Pi computer as a wireless control device is also illustrated. Performance of the syringe pump was assessed and the methods used for assessment are detailed. The cost of the entire system, including the controller and web-based control interface, is on the order of 5% or less than one would expect to pay for a commercial syringe pump having similar performance. The design should suit the needs of a given research activity requiring a syringe pump including carefully controlled dosing of reagents, pharmaceuticals, and delivery of viscous 3-D printer media among other applications. PMID:25229451

“Let the Algorithm Do the Work”: Reduction of Hypoglycemia Using Sensor-Augmented Pump Therapy with Predictive Insulin Suspension (SmartGuard) in Pediatric Type 1 Diabetes Patients

PubMed Central

Kordonouri, Olga; Holder, Martin; Remus, Kerstin; Kieninger-Baum, Dorothee; Wadien, Tanja; Danne, Thomas

2017-01-01

Abstract Background: A sensor-augmented insulin pump (SAP) using the MiniMed® 640G system with SmartGuard™ technology allows an automatic stop of insulin delivery based on prediction of low glucose levels. Since pediatric patients are particularly prone to hypoglycemia, this device may offer additional protection beyond conventional sensor-augmented therapy. Methods: This prospective, pediatric multicenter user evaluation assessed 6 weeks of SAP with SmartGuard (threshold setting for hypoglycemia: 70 mg/dL) compared to a preceding period of 2 weeks with SAP only. The primary outcome was the potential reduction in the frequency of hypoglycemic episodes and hypoglycemic intensity (area under the curve [AUC] and time <70 mg/dL). Results: The study included 24 patients with at least 3 months of insulin pump use (average age: 11.6 ± 5.1 years, 15 female, average type 1 diabetes duration: 7.5 ± 4.2 years, mean ± SD) who had on average 3.2 ± 1.0 predictive suspensions/patient/day. The mean sensor glucose minimum during suspension was 78 ± 6 mg/dL and the average suspension time was 155 ± 47 min/day. Use of SmartGuard in patients treated as per the protocol (n = 18) reduced the number of instances in which the glucose level was <70 mg/dL (1.02 ± 0.52 to 0.72 ± 0.36; P = 0.027), as well as AUC <70 mg/dL (0.76 ± 0.73 to 0.38 ± 0.24; P = 0.027) and the time/day the level fell below 70 mg/dL (73 ± 56 to 31 ± 22 min). The reduction of hypoglycemia was not associated with a significant change in mean glucose concentration (171 ± 26 to 180 ± 19 mg/dL, P = 0.111) and HbA1c (7.5% ± 0.5% to 7.6% ± 0.7%, (P = 0.329). Manual resumption of insulin delivery followed by carbohydrate intake resulted in significantly higher glucose levels 1 h after suspension compared to SmartGuard suspensions with automatic resume (190.8 ± 26.5 vs. 138.7 ± 10.3 mg/dL; P < 0.001). Conclusions: SmartGuard technology significantly reduced the risk for hypoglycemia in pediatric type 1 diabetes patients without increasing HbA1c. Patients must be educated that when using combining predictive low-glucose insulin suspension technology, extra carbohydrate intake in response to an alarm combined with manual resumption is likely to cause rebound hyperglycemia. The best results were achieved when the user did not interfere with pump operation. PMID:28099035

"Let the Algorithm Do the Work": Reduction of Hypoglycemia Using Sensor-Augmented Pump Therapy with Predictive Insulin Suspension (SmartGuard) in Pediatric Type 1 Diabetes Patients.

PubMed

Biester, Torben; Kordonouri, Olga; Holder, Martin; Remus, Kerstin; Kieninger-Baum, Dorothee; Wadien, Tanja; Danne, Thomas

2017-03-01

A sensor-augmented insulin pump (SAP) using the MiniMed ® 640G system with SmartGuard™ technology allows an automatic stop of insulin delivery based on prediction of low glucose levels. Since pediatric patients are particularly prone to hypoglycemia, this device may offer additional protection beyond conventional sensor-augmented therapy. This prospective, pediatric multicenter user evaluation assessed 6 weeks of SAP with SmartGuard (threshold setting for hypoglycemia: 70 mg/dL) compared to a preceding period of 2 weeks with SAP only. The primary outcome was the potential reduction in the frequency of hypoglycemic episodes and hypoglycemic intensity (area under the curve [AUC] and time <70 mg/dL). The study included 24 patients with at least 3 months of insulin pump use (average age: 11.6 ± 5.1 years, 15 female, average type 1 diabetes duration: 7.5 ± 4.2 years, mean ± SD) who had on average 3.2 ± 1.0 predictive suspensions/patient/day. The mean sensor glucose minimum during suspension was 78 ± 6 mg/dL and the average suspension time was 155 ± 47 min/day. Use of SmartGuard in patients treated as per the protocol (n = 18) reduced the number of instances in which the glucose level was <70 mg/dL (1.02 ± 0.52 to 0.72 ± 0.36; P = 0.027), as well as AUC <70 mg/dL (0.76 ± 0.73 to 0.38 ± 0.24; P = 0.027) and the time/day the level fell below 70 mg/dL (73 ± 56 to 31 ± 22 min). The reduction of hypoglycemia was not associated with a significant change in mean glucose concentration (171 ± 26 to 180 ± 19 mg/dL, P = 0.111) and HbA1c (7.5% ± 0.5% to 7.6% ± 0.7%, (P = 0.329). Manual resumption of insulin delivery followed by carbohydrate intake resulted in significantly higher glucose levels 1 h after suspension compared to SmartGuard suspensions with automatic resume (190.8 ± 26.5 vs. 138.7 ± 10.3 mg/dL; P < 0.001). SmartGuard technology significantly reduced the risk for hypoglycemia in pediatric type 1 diabetes patients without increasing HbA1c. Patients must be educated that when using combining predictive low-glucose insulin suspension technology, extra carbohydrate intake in response to an alarm combined with manual resumption is likely to cause rebound hyperglycemia. The best results were achieved when the user did not interfere with pump operation.

Multicenter User Evaluation of ACCU-CHEK® Combo, an Integrated System for Continuous Subcutaneous Insulin Infusion

PubMed Central

Kerr, David; Hoogma, Roel P.L.M; Buhr, Andreas; Petersen, Bettina; Storms, Fred E.M.G

2010-01-01

Background The aim of this study was to evaluate a newly developed system for insulin delivery incorporating a multifunctional blood glucose meter and a remotely controlled insulin pump (ACCU-CHEK® Combo system) in established pump users with type 1 diabetes. The technology was assessed both from device performance and subject usability perspectives. Method A multicenter, prospective, single group study was carried out in five centers in the Netherlands and four centers in the United Kingdom for more than 6 months. The study was divided into two phases: Phase 1 (4 weeks) for device validation purposes and phase 2 (22 weeks) to observe the impact of the system on metabolic control, patient satisfaction [using the Diabetes Treatment Satisfaction Questionnaire (DTSQ)] and device safety. Results Eighty subjects completed the planned study period. There were no unexpected device errors. Treatment satisfaction was high at baseline and further increased to study end (DTSQ change version: sum score, 10.6 ± 7.2; scale score range, -18 to +18, p < 0.0001). Hemoglobin A1c improved continuously over time, from 7.9% (±0.9%) to 7.7% (±0.8%) at month 3 (p < 0.001) and 7.6% (±0.8%) at month 6 (p < 0.0001). The frequency of severe hypoglycemia was 0.08 per patient years. There was no case of ketoacidosis. Conclusions The new system was evaluated by experienced continuous subcutaneous insulin infusion users as safe in daily practice and associated with favorable treatment satisfaction and a modest improvement in glycemic control. PMID:21129336

Self-powered enzyme micropumps

NASA Astrophysics Data System (ADS)

Sengupta, Samudra; Patra, Debabrata; Ortiz-Rivera, Isamar; Agrawal, Arjun; Shklyaev, Sergey; Dey, Krishna K.; Córdova-Figueroa, Ubaldo; Mallouk, Thomas E.; Sen, Ayusman

2014-05-01

Non-mechanical nano- and microscale pumps that function without the aid of an external power source and provide precise control over the flow rate in response to specific signals are needed for the development of new autonomous nano- and microscale systems. Here we show that surface-immobilized enzymes that are independent of adenosine triphosphate function as self-powered micropumps in the presence of their respective substrates. In the four cases studied (catalase, lipase, urease and glucose oxidase), the flow is driven by a gradient in fluid density generated by the enzymatic reaction. The pumping velocity increases with increasing substrate concentration and reaction rate. These rechargeable pumps can be triggered by the presence of specific analytes, which enables the design of enzyme-based devices that act both as sensor and pump. Finally, we show proof-of-concept enzyme-powered devices that autonomously deliver small molecules and proteins in response to specific chemical stimuli, including the release of insulin in response to glucose.

Insulin algorithms in the self-management of insulin-dependent diabetes: the interactive 'Apple Juice' program.

PubMed

Williams, A G

1996-01-01

The 'Apple Juice' program is an interactive diabetes self-management program which runs on a lap-top Macintosh Powerbook 100 computer. The dose-by-dose insulin advisory program was initially designed for children with insulin-dependent (type 1) diabetes mellitus. It utilizes several different insulin algorithms, measurement formulae, and compensation factors for meals, activity, medication and the dawn phenomenon. It was developed to assist the individual with diabetes and/or care providers, in determining specific insulin dosage recommendations throughout a 24 h period. Information technology functions include, but are not limited to automated record keeping, data recall, event reminders, data trend/pattern analyses and education. This paper highlights issues, observations and recommendations surrounding the use of the current version of the software, along with a detailed description of the insulin algorithms and measurement formulae applied successfully with the author's daughter over a six year period.

Continuous Glucose Monitoring: A Review of Successes, Challenges, and Opportunities.

PubMed

Rodbard, David

2016-02-01

Continuous glucose monitoring (CGM) provides information unattainable by intermittent capillary blood glucose, including instantaneous real-time display of glucose level and rate of change of glucose, alerts and alarms for actual or impending hypo- and hyperglycemia, "24/7" coverage, and the ability to characterize glycemic variability. Progressively more accurate and precise, reasonably unobtrusive, small, comfortable, user-friendly devices connect to the Internet to share information and are sine qua non for a closed-loop artificial pancreas. CGM can inform, educate, motivate, and alert people with diabetes. CGM is medically indicated for patients with frequent, severe, or nocturnal hypoglycemia, especially in the presence of hypoglycemia unawareness. Surprisingly, despite tremendous advances, utilization of CGM has remained fairly limited to date. Barriers to use have included the following: (1) lack of Food and Drug Administration approval, to date, for insulin dosing ("nonadjuvant use") in the United States and for use in hospital and intensive care unit settings; (2) cost and variable reimbursement; (3) need for recalibrations; (4) periodic replacement of sensors; (5) day-to-day variability in glycemic patterns, which can limit the predictability of findings based on retrospective, masked "professional" use; (6) time, implicit costs, and inconvenience for uploading of data for retrospective analysis; (7) lack of fair and reasonable reimbursement for physician time; (8) inexperience and lack of training of physicians and other healthcare professionals regarding interpretation of CGM results; (9) lack of standardization of software methods for analysis of CGM data; and (10) need for professional medical organizations to develop and disseminate additional clinical practice guidelines regarding the role of CGM. Ongoing advances in technology and clinical research have addressed several of these barriers. Use of CGM in conjunction with an insulin pump with automated suspension of insulin infusion in response to actual observed or predicted hypoglycemia, as well as progressive refinement of closed-loop systems, is expected to dramatically enhance the clinical utility and utilization of CGM.

Continuous Glucose Monitoring: A Review of Successes, Challenges, and Opportunities

PubMed Central

2016-01-01

Abstract Continuous glucose monitoring (CGM) provides information unattainable by intermittent capillary blood glucose, including instantaneous real-time display of glucose level and rate of change of glucose, alerts and alarms for actual or impending hypo- and hyperglycemia, “24/7” coverage, and the ability to characterize glycemic variability. Progressively more accurate and precise, reasonably unobtrusive, small, comfortable, user-friendly devices connect to the Internet to share information and are sine qua non for a closed-loop artificial pancreas. CGM can inform, educate, motivate, and alert people with diabetes. CGM is medically indicated for patients with frequent, severe, or nocturnal hypoglycemia, especially in the presence of hypoglycemia unawareness. Surprisingly, despite tremendous advances, utilization of CGM has remained fairly limited to date. Barriers to use have included the following: (1) lack of Food and Drug Administration approval, to date, for insulin dosing (“nonadjuvant use”) in the United States and for use in hospital and intensive care unit settings; (2) cost and variable reimbursement; (3) need for recalibrations; (4) periodic replacement of sensors; (5) day-to-day variability in glycemic patterns, which can limit the predictability of findings based on retrospective, masked “professional” use; (6) time, implicit costs, and inconvenience for uploading of data for retrospective analysis; (7) lack of fair and reasonable reimbursement for physician time; (8) inexperience and lack of training of physicians and other healthcare professionals regarding interpretation of CGM results; (9) lack of standardization of software methods for analysis of CGM data; and (10) need for professional medical organizations to develop and disseminate additional clinical practice guidelines regarding the role of CGM. Ongoing advances in technology and clinical research have addressed several of these barriers. Use of CGM in conjunction with an insulin pump with automated suspension of insulin infusion in response to actual observed or predicted hypoglycemia, as well as progressive refinement of closed-loop systems, is expected to dramatically enhance the clinical utility and utilization of CGM. PMID:26784127

Using failure mode and effects analysis to plan implementation of smart i.v. pump technology.

PubMed

Wetterneck, Tosha B; Skibinski, Kathleen A; Roberts, Tanita L; Kleppin, Susan M; Schroeder, Mark E; Enloe, Myra; Rough, Steven S; Hundt, Ann Schoofs; Carayon, Pascale

2006-08-15

Failure mode and effects analysis (FMEA) was used to evaluate a smart i.v. pump as it was implemented into a redesigned medication-use process. A multidisciplinary team conducted a FMEA to guide the implementation of a smart i.v. pump that was designed to prevent pump programming errors. The smart i.v. pump was equipped with a dose-error reduction system that included a pre-defined drug library in which dosage limits were set for each medication. Monitoring for potential failures and errors occurred for three months postimplementation of FMEA. Specific measures were used to determine the success of the actions that were implemented as a result of the FMEA. The FMEA process at the hospital identified key failure modes in the medication process with the use of the old and new pumps, and actions were taken to avoid errors and adverse events. I.V. pump software and hardware design changes were also recommended. Thirteen of the 18 failure modes reported in practice after pump implementation had been identified by the team. A beneficial outcome of FMEA was the development of a multidisciplinary team that provided the infrastructure for safe technology implementation and effective event investigation after implementation. With the continual updating of i.v. pump software and hardware after implementation, FMEA can be an important starting place for safe technology choice and implementation and can produce site experts to follow technology and process changes over time. FMEA was useful in identifying potential problems in the medication-use process with the implementation of new smart i.v. pumps. Monitoring for system failures and errors after implementation remains necessary.

Insulin and Leptin Relations in Obesity: A Multimedia Approach

ERIC Educational Resources Information Center

Yokaichiya, Daniela K.; Galembeck, Eduardo; Torres, Bayardo B.; Da Silva, Jose Antonio; de Araujo, Daniele R.

2008-01-01

Obesity has been recognized as a worldwide public health problem. It significantly increases the chances of developing several diseases, including Type II diabetes. The roles of insulin and leptin in obesity involve reactions that can be better understood when they are presented step by step. The aim of this work was to design software with data…

Insulin deficiency with and without glucagon: A comparative study between total pancreatectomy and type 1 diabetes.

PubMed

Niwano, Fumimaru; Hiromine, Yoshihisa; Noso, Shinsuke; Babaya, Naru; Ito, Hiroyuki; Yasutake, Sara; Matsumoto, Ippei; Takeyama, Yoshifumi; Kawabata, Yumiko; Ikegami, Hiroshi

2017-12-30

Patients with a total pancreatectomy and type 1 diabetes are similar in regard to absolute insulin deficiency, but different in regard to glucagon, providing a unique opportunity to study the contribution of glucagon to glucose metabolism in an insulin-dependent state. The aim of the present study was to investigate the contribution of glucagon to glucose homeostasis in complete insulin deficiency in vivo. A total of 38 individuals with a complete lack of endogenous insulin (fasting C-peptide <0.0066 nmol/L) and whose glycemic control was optimized with an insulin pump during hospitalization were retrospectively studied. The basal insulin requirement, time-to-time adjustment of the basal insulin infusion rate, prandial insulin requirement and fasting plasma glucagon were compared between patients with a total pancreatectomy (n = 10) and those with type 1 diabetes (n = 28) after achievement of optimal glycemic control. Total daily insulin (P = 0.03) and basal insulin (P = 0.000006), but not prandial insulin requirements, were significantly lower in total pancreatectomy patients than in type 1 diabetes patients. The basal percentage (basal insulin/total daily insulin) was also significantly lower in total pancreatectomy patients than in type 1 diabetes patients (15.8 ± 7.8 vs 32.9 ± 10.1%, P = 0.00003). An increase in the insulin infusion rate early in the morning was not necessary in most patients with a pancreatectomy. The fasting plasma glucagon concentration was significantly lower in total pancreatectomy patients than in type 1 diabetes patients (P = 0.00007), and was positively correlated with the basal insulin requirement (P = 0.038). The difference in insulin requirements between total pancreatectomy and type 1 diabetes patients suggests a contribution of glucagon to the basal insulin requirement and dawn phenomenon. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

[Nocturnal continuous subcutaneous insulin infusion--a therapeutic possibility in labile type I diabetes under exceptional conditions].

PubMed

Bruns, W; Steinborn, F; Menzel, R; Staritz, B; Bibergeil, H

1990-03-15

The whole-day continuous subcutaneous insulin infusion (CSII) with portable pumps in daily blood glucose autocontrol guarantees a more stabile and favourable glycaemia than multiple injections in labile type I diabetics. The success is mainly to be traced back to the continuous replacement of the basal secretion, particularly to the nocturnal fasting phase. In this study the effect on the glycaemia is investigated with exclusively nocturnal administration of the CSII under maintenance of multiple insulin injections during this day. In a group of 18 type I diabetics the nocturnal CSII in comparison to intermediate insulin administrations in the evening led to a significant improvement of glycaemia (p less than 0.01), in particular to the decrease of the fasting blood sugars (p less than 0.05). In two casuistic observations in comparison to all the other conventional methods for the compensation of the nocturnal glycaemia (depot insulin, nocturnal injection of normal insulin) the nocturnal CSII proved to be superior. Therefore, the nocturnal CSII is an--though more rarely to be used--alternative, which may be taken into consideration, of a whole-day CSII is temporarily unwished for.

Glucose-responsive insulin delivery for type 1 diabetes: The artificial pancreas story.

PubMed

Bally, Lia; Thabit, Hood; Hovorka, Roman

2018-06-15

Insulin replacement therapy is integral to the management of type 1 diabetes, which is characterised by absolute insulin deficiency. Optimal glycaemic control, as assessed by glycated haemoglobin, and avoidance of hyper- and hypoglycaemic excursions have been shown to prevent diabetes-related complications. Insulin pump use has increased considerably over the past decade with beneficial effects on glycaemic control, quality of life and treatment satisfaction. The advent and progress of ambulatory glucose sensor technology has enabled continuous glucose monitoring based on real-time glucose levels to be integrated with insulin therapy. Low glucose and predictive low glucose suspend systems are currently used in clinical practice to mitigate against hypoglycaemia, and provide the first step towards feedback glucose control. The more advanced technology approach, an artificial pancreas or a closed-loop system, gradually increases and decreases insulin delivery in a glucose-responsive fashion to mitigate against hyper- and hypoglycaemia. Randomised outpatient clinical trials over the past 5 years have demonstrated the feasibility, safety and efficacy of the approach, and the recent FDA approval of the first single hormone closed-loop system establishes a new standard of care for people with type 1 diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

Direct Observation of Insulin Association Dynamics with Time-Resolved X-ray Scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rimmerman, Dolev; Leshchev, Denis; Hsu, Darren J.

Biological functions frequently require protein-protein interactions that involve secondary and tertiary structural perturbation. Here we study protein-protein dissociation and reassociation dynamics in insulin, a model system for protein oligomerization. Insulin dimer dissociation into monomers was induced by a nanosecond temperature-jump (T-jump) of ~8 °C in aqueous solution, and the resulting protein and solvent dynamics were tracked by time-resolved X-ray solution scattering (TRXSS) on time scales of 10 ns to 100 ms. The protein scattering signals revealed the formation of five distinguishable transient species during the association process that deviate from simple two state kinetics. Our results show that the combinationmore » of T-jump pump coupled to TRXSS probe allows for direct tracking of structural dynamics in nonphotoactive proteins.« less

Depolymerization of insulin amyloid fibrils by albumin-modified magnetic fluid

NASA Astrophysics Data System (ADS)

Siposova, Katarina; Kubovcikova, Martina; Bednarikova, Zuzana; Koneracka, Martina; Zavisova, Vlasta; Antosova, Andrea; Kopcansky, Peter; Daxnerova, Zuzana; Gazova, Zuzana

2012-02-01

Pathogenesis of amyloid-related diseases is associated with the presence of protein amyloid deposits. Insulin amyloids have been reported in a patient with diabetes undergoing treatment by injection of insulin and causes problems in the production and storage of this drug and in application of insulin pumps. We have studied the interference of insulin amyloid fibrils with a series of 18 albumin magnetic fluids (MFBSAs) consisting of magnetite nanoparticles modified by different amounts of bovine serum albumin (w/w BSA/Fe3O4 from 0.005 up to 15). We have found that MFBSAs are able to destroy amyloid fibrils in vitro. The extent of fibril depolymerization was affected by nanoparticle physical-chemical properties (hydrodynamic diameter, zeta potential and isoelectric point) determined by the BSA amount present in MFBSAs. The most effective were MFBSAs with lower BSA/Fe3O4 ratios (from 0.005 to 0.1) characteristic of about 90% depolymerizing activity. For the most active magnetic fluids (ratios 0.01 and 0.02) the DC50 values were determined in the range of low concentrations, indicating their ability to interfere with insulin fibrils at stoichiometric concentrations. We assume that the present findings represent a starting point for the application of the active MFBSAs as therapeutic agents targeting insulin amyloidosis.

Continuous subcutaneous insulin infusion allows tolerance induction and diabetes treatment in a type 1 diabetic child with insulin allergy.

PubMed

Hasselmann, C; Pecquet, C; Bismuth, E; Raverdy, C; Sola-Gazagnes, A; Lobut, J-B; Carel, J-C; Tubiana-Rufi, N

2013-04-01

Insulin allergy is a rare but serious and challenging condition in patients with type 1 diabetes (T1D). This is a case report of an 8-year-old boy with T1D and an allergy to insulin. Three months after being diagnosed with T1D, the patient developed progressive skin reactions to insulin, characterized by small 1.5-cm pruritic wheals at injection sites that persisted for several days. Seven months after diagnosis, he experienced two episodes of generalized urticaria with systemic symptoms that were seen within a few seconds of insulin injection. Examination revealed lipoatrophy of the thighs. Intradermal skin tests were positive for protamine, glargine and lispro. The patient was started on a continuous subcutaneous insulin infusion (CSII) tolerance induction protocol, consisting of a very low basal rate that was progressively increased, with the first bolus given under medical supervision, and was well tolerated for 4 months. After this period of time, the skin wheals reappeared, localized to the infusion sites, but without urticaria or any other generalized reactions. Intradermal skin tests were repeated and were again positive. Serum insulin-specific IgE measured 30 months after the first allergic reactions were positive. After 3 years, pump therapy is ongoing and blood glucose control has remained relatively good (HbA1c 7.6%). In T1D children with insulin allergy, CSII can successfully be used to both induce insulin tolerance and allow diabetes insulin therapy, although insulin desensitization cannot always be fully achieved. The induction protocol was easily manageable partly due to the "honeymoon" period that the patient was still in, but it should nonetheless be used even when the patient has higher insulin requirements. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Design of water pumping system by wind turbine for using in coastal areas of Bangladesh

NASA Astrophysics Data System (ADS)

Alam, Muhammad Mahbubul; Tasnim, Tamanna; Doha, Umnia

2017-06-01

In this work, a theoretical analysis has been carried out to analyze the prospect of Wind Pumping System (WPS) for using in coastal areas of Bangladesh. Wind speed data of three coastal areas of Bangladesh-Kutubdia, Patenga and Sathkhira has been analyzed and an optimal wind turbine viable for this wind speed range has been designed using the simulation software Q-blade. The simulated turbine is then coupled with a rotodynamic pump. The output of the Wind Pumping System (WPS) for the three coastal areas has been studied.

Continuous subcutaneous insulin infusion in diabetes: patient populations, safety, efficacy, and pharmacoeconomics.

PubMed

Pozzilli, Paolo; Battelino, Tadej; Danne, Thomas; Hovorka, Roman; Jarosz-Chobot, Przemyslawa; Renard, Eric

2016-01-01

The level of glycaemic control necessary to achieve optimal short-term and long-term outcomes in subjects with type 1 diabetes mellitus (T1DM) typically requires intensified insulin therapy using multiple daily injections or continuous subcutaneous insulin infusion. For continuous subcutaneous insulin infusion, the insulins of choice are the rapid-acting insulin analogues, insulin aspart, insulin lispro and insulin glulisine. The advantages of continuous subcutaneous insulin infusion over multiple daily injections in adult and paediatric populations with T1DM include superior glycaemic control, lower insulin requirements and better health-related quality of life/patient satisfaction. An association between continuous subcutaneous insulin infusion and reduced hypoglycaemic risk is more consistent in children/adolescents than in adults. The use of continuous subcutaneous insulin infusion is widely recommended in both adult and paediatric T1DM populations but is limited in pregnant patients and those with type 2 diabetes mellitus. All available rapid-acting insulin analogues are approved for use in adult, paediatric and pregnant populations. However, minimum patient age varies (insulin lispro: no minimum; insulin aspart: ≥2 years; insulin glulisine: ≥6 years) and experience in pregnancy ranges from extensive (insulin aspart, insulin lispro) to limited (insulin glulisine). Although more expensive than multiple daily injections, continuous subcutaneous insulin infusion is cost-effective in selected patient groups. This comprehensive review focuses on the European situation and summarises evidence for the efficacy and safety of continuous subcutaneous insulin infusion, particularly when used with rapid-acting insulin analogues, in adult, paediatric and pregnant populations. The review also discusses relevant European guidelines; reviews issues that surround use of this technology; summarises the effects of continuous subcutaneous insulin infusion on patients' health-related quality of life; reviews relevant pharmacoeconomic data; and discusses recent advances in pump technology, including the development of closed-loop 'artificial pancreas' systems. © 2015 The Authors. Diabetes/Metabolism Research and Reviews Published by John Wiley & Sons Ltd. © 2015 The Authors. Diabetes/Metabolism Research and Reviews Published by John Wiley & Sons Ltd.

Youth and parent feelings about type 1 diabetes (T1D) management technologies

USDA-ARS?s Scientific Manuscript database

Use of T1D management technologies, including insulin pumps and continuous glucose monitors, is rapidly growing. However, research has only recently begun to evaluate youth and parent feelings about and experiences with using these technologies and the relationship with health-related quality of lif...

High Stability Metal-Protein Interactions Evaluated by Microcalorimetry

DTIC Science & Technology

2016-04-29

microprocessor -controlled internal vacuum pump runs for a 90 second period, then it evaluates the vacuum pressure attained, and if that value meets spec...and the other with the software. There is a place in the wash module program where the ITC’s microprocessor - controlled internal vacuum pump runs for

Body mass index standard deviation score and obesity in children with type 1 diabetes in the Nordic countries. HbA1c and other predictors of increasing BMISDS.

PubMed

Birkebaek, N H; Kahlert, J; Bjarnason, R; Drivvoll, A K; Johansen, A; Konradsdottir, E; Pundziute-Lyckå, A; Samuelsson, U; Skrivarhaug, T; Svensson, J

2018-05-21

Intensified insulin therapy may increase body weight and cause obesity. This study compared body mass index standard deviation score (BMISDS) and obesity rate in children with type 1 diabetes (T1D) in Denmark, Iceland, Norway and Sweden, and uncovered predictors for increasing BMISDS. Data registered in the Nordic national childhood diabetes databases during the period 2008-2012 on children below 15 years with T1D for more than 3 months were compiled, including information on gender, age, diabetes duration, hemoglobin A 1c (HbA 1c ), insulin dose, severe hypoglycemia (SH), treatment modality, height and weight. The Swedish reference chart for BMI was used for calculating BMISDS. Totally, 11 025 children (48% females) (30 994 registrations) were included. Medians by the last recorded examination were: age, 13.5 years; diabetes duration, 4.3 years; HbA 1c , 7.9% (63 mmol/mol); insulin dose, 0.8 IU/kg/d and BMISDS, 0.70. Obesity rate was 18.5%. Adjusted mean BMISDS (BMISDS adj) was inversely related to HbA 1c and directly to diabetes duration. Higher BMISDS adj was found in those with an insulin dose above 0.6 IU/kg/d, and in girls above 10 years. Pump users had higher BMISDS adj than pen users, and patients with registered SH had higher BMISDS adj than patients without SH (both P < .001). Obesity rate in children with T1D in the Nordic countries is high, however, with country differences. Low HbA 1c , long diabetes duration, higher insulin dose, pump treatment and experiencing a SH predicted higher BMISDS. Diabetes caregivers should balance the risk of obesity and the benefit of a very low HbA 1c. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Improving the estimation of mealtime insulin dose in adults with type 1 diabetes: the Normal Insulin Demand for Dose Adjustment (NIDDA) study.

PubMed

Bao, Jiansong; Gilbertson, Heather R; Gray, Robyn; Munns, Diane; Howard, Gabrielle; Petocz, Peter; Colagiuri, Stephen; Brand-Miller, Jennie C

2011-10-01

Although carbohydrate counting is routine practice in type 1 diabetes, hyperglycemic episodes are common. A food insulin index (FII) has been developed and validated for predicting the normal insulin demand generated by mixed meals in healthy adults. We sought to compare a novel algorithm on the basis of the FII for estimating mealtime insulin dose with carbohydrate counting in adults with type 1 diabetes. A total of 28 patients using insulin pump therapy consumed two different breakfast meals of equal energy, glycemic index, fiber, and calculated insulin demand (both FII = 60) but approximately twofold difference in carbohydrate content, in random order on three consecutive mornings. On one occasion, a carbohydrate-counting algorithm was applied to meal A (75 g carbohydrate) for determining bolus insulin dose. On the other two occasions, carbohydrate counting (about half the insulin dose as meal A) and the FII algorithm (same dose as meal A) were applied to meal B (41 g carbohydrate). A real-time continuous glucose monitor was used to assess 3-h postprandial glycemia. Compared with carbohydrate counting, the FII algorithm significantly decreased glucose incremental area under the curve over 3 h (-52%, P = 0.013) and peak glucose excursion (-41%, P = 0.01) and improved the percentage of time within the normal blood glucose range (4-10 mmol/L) (31%, P = 0.001). There was no significant difference in the occurrence of hypoglycemia. An insulin algorithm based on physiological insulin demand evoked by foods in healthy subjects may be a useful tool for estimating mealtime insulin dose in patients with type 1 diabetes.

Automated control of an adaptive bi-hormonal, dual-sensor artificial pancreas and evaluation during inpatient studies

PubMed Central

Jacobs, Peter G.; El Youssef, Joseph; Castle, Jessica; Bakhtiani, Parkash; Branigan, Deborah; Breen, Matthew; Bauer, David; Preiser, Nicholas; Leonard, Gerald; Stonex, Tara; Preiser, Nicholas; Ward, W. Kenneth

2014-01-01

Automated control of blood glucose in patients with type 1 diabetes has not yet been fully implemented. The aim of this study was to design and clinically evaluate a system that integrates a control algorithm with off-the-shelf subcutaneous sensors and pumps to automate the delivery of the hormones glucagon and insulin in response to continuous glucose sensor measurements. The automated component of the system runs an adaptive proportional derivative control algorithm which determines hormone delivery rates based on the sensed glucose measurements and the meal announcements by the patient. We provide details about the system design and the control algorithm, which incorporates both a fading memory proportional derivative controller (FMPD) and an adaptive system for estimating changing sensitivity to insulin based on a glucoregulatory model of insulin action. For an inpatient study carried out in eight subjects using Dexcom SEVEN PLUS sensors, pre-study HbA1c averaged 7.6, which translates to an estimated average glucose of 171 mg/dL. In contrast, during use of the automated system, after initial stabilization, glucose averaged 145 mg/dL and subjects were kept within the euglycemic range (between 70 and 180 mg/dL) for 73.1% of the time, indicating improved glycemic control. A further study on five additional subjects in which we used a newer and more reliable glucose sensor (Dexcom G4 PLATINUM) and made improvements to the insulin and glucagon pump communication system resulted in elimination of hypoglycemic events. For this G4 study, the system was able to maintain subjects’ glucose levels within the near-euglycemic range for 71.6% of the study duration and the mean venous glucose level was 151 mg/dL. PMID:24835122

Effectiveness of a Predictive Algorithm in the Prevention of Exercise-Induced Hypoglycemia in Type 1 Diabetes.

PubMed

Abraham, Mary B; Davey, Raymond; O'Grady, Michael J; Ly, Trang T; Paramalingam, Nirubasini; Fournier, Paul A; Roy, Anirban; Grosman, Benyamin; Kurtz, Natalie; Fairchild, Janice M; King, Bruce R; Ambler, Geoffrey R; Cameron, Fergus; Jones, Timothy W; Davis, Elizabeth A

2016-09-01

Sensor-augmented pump therapy (SAPT) with a predictive algorithm to suspend insulin delivery has the potential to reduce hypoglycemia, a known obstacle in improving physical activity in patients with type 1 diabetes. The predictive low glucose management (PLGM) system employs a predictive algorithm that suspends basal insulin when hypoglycemia is predicted. The aim of this study was to determine the efficacy of this algorithm in the prevention of exercise-induced hypoglycemia under in-clinic conditions. This was a randomized, controlled cross-over study in which 25 participants performed 2 consecutive sessions of 30 min of moderate-intensity exercise while on basal continuous subcutaneous insulin infusion on 2 study days: a control day with SAPT alone and an intervention day with SAPT and PLGM. The predictive algorithm suspended basal insulin when sensor glucose was predicted to be below the preset hypoglycemic threshold in 30 min. We tested preset hypoglycemic thresholds of 70 and 80 mg/dL. The primary outcome was the requirement for hypoglycemia treatment (symptomatic hypoglycemia with plasma glucose <63 mg/dL or plasma glucose <50 mg/dL) and was compared in both control and intervention arms. Results were analyzed in 19 participants. In the intervention arm with both thresholds, only 6 participants (32%) required treatment for hypoglycemia compared with 17 participants (89%) in the control arm (P = 0.003). In participants with a 2-h pump suspension on intervention days, the plasma glucose was 84 ± 12 and 99 ± 24 mg/dL at thresholds of 70 and 80 mg/dL, respectively. SAPT with PLGM reduced the need for hypoglycemia treatment after moderate-intensity exercise in an in-clinic setting.

Randomized trial of a dual-hormone artificial pancreas with dosing adjustment during exercise compared with no adjustment and sensor-augmented pump therapy.

PubMed

Jacobs, P G; El Youssef, J; Reddy, R; Resalat, N; Branigan, D; Condon, J; Preiser, N; Ramsey, K; Jones, M; Edwards, C; Kuehl, K; Leitschuh, J; Rajhbeharrysingh, U; Castle, J R

2016-11-01

To test whether adjusting insulin and glucagon in response to exercise within a dual-hormone artificial pancreas (AP) reduces exercise-related hypoglycaemia. In random order, 21 adults with type 1 diabetes (T1D) underwent three 22-hour experimental sessions: AP with exercise dosing adjustment (APX); AP with no exercise dosing adjustment (APN); and sensor-augmented pump (SAP) therapy. After an overnight stay and 2 hours after breakfast, participants exercised for 45 minutes at 60% of their maximum heart rate, with no snack given before exercise. During APX, insulin was decreased and glucagon was increased at exercise onset, while during SAP therapy, subjects could adjust dosing before exercise. The two primary outcomes were percentage of time spent in hypoglycaemia (<3.9 mmol/L) and percentage of time spent in euglycaemia (3.9-10 mmol/L) from the start of exercise to the end of the study. The mean (95% confidence interval) times spent in hypoglycaemia (<3.9 mmol/L) after the start of exercise were 0.3% (-0.1, 0.7) for APX, 3.1% (0.8, 5.3) for APN, and 0.8% (0.1, 1.4) for SAP therapy. There was an absolute difference of 2.8% less time spent in hypoglycaemia for APX versus APN (p = .001) and 0.5% less time spent in hypoglycaemia for APX versus SAP therapy (p = .16). Mean time spent in euglycaemia was similar across the different sessions. Adjusting insulin and glucagon delivery at exercise onset within a dual-hormone AP significantly reduces hypoglycaemia compared with no adjustment and performs similarly to SAP therapy when insulin is adjusted before exercise. © 2016 John Wiley & Sons Ltd.

Usability of Medical Devices for Patients With Diabetes Who Are Visually Impaired or Blind

PubMed Central

Heinemann, Lutz; Drossel, Diana; Freckmann, Guido; Kulzer, Bernhard

2016-01-01

The estimation is that every third to fourth patient with diabetes suffers from some degree of diabetic retinopathy. Medical products for insulin administration (such as insulin pens and pumps) or glucose monitoring not optimized to the needs of these patients’ represent a high barrier for optimal diabetes therapy in daily practice. To date, the number of devices suitable for visually impaired and blind patients with diabetes is scarce. This manuscript outlines the specific needs of this patient group with regard to systems for insulin administration, blood glucose measurement, and continuous glucose monitoring. We see the clear need for a policy requirement for manufacturers to provide accessible/user friendly technical aids for visually impaired and blind patients with diabetes. This would represent an important step toward improving the situation for this impressively large patient group. PMID:27605593

PSECMAC intelligent insulin schedule for diabetic blood glucose management under nonmeal announcement.

PubMed

Teddy, S D; Quek, C; Lai, E M-K; Cinar, A

2010-03-01

Therapeutically, the closed-loop blood glucose-insulin regulation paradigm via a controllable insulin pump offers a potential solution to the management of diabetes. However, the development of such a closed-loop regulatory system to date has been hampered by two main issues: 1) the limited knowledge on the complex human physiological process of glucose-insulin metabolism that prevents a precise modeling of the biological blood glucose control loop; and 2) the vast metabolic biodiversity of the diabetic population due to varying exogneous and endogenous disturbances such as food intake, exercise, stress, and hormonal factors, etc. In addition, current attempts of closed-loop glucose regulatory techniques generally require some form of prior meal announcement and this constitutes a severe limitation to the applicability of such systems. In this paper, we present a novel intelligent insulin schedule based on the pseudo self-evolving cerebellar model articulation controller (PSECMAC) associative learning memory model that emulates the healthy human insulin response to food ingestion. The proposed PSECMAC intelligent insulin schedule requires no prior meal announcement and delivers the necessary insulin dosage based only on the observed blood glucose fluctuations. Using a simulated healthy subject, the proposed PSECMAC insulin schedule is demonstrated to be able to accurately capture the complex human glucose-insulin dynamics and robustly addresses the intraperson metabolic variability. Subsequently, the PSECMAC intelligent insulin schedule is employed on a group of type-1 diabetic patients to regulate their impaired blood glucose levels. Preliminary simulation results are highly encouraging. The work reported in this paper represents a major paradigm shift in the management of diabetes where patient compliance is poor and the need for prior meal announcement under current treatment regimes poses a significant challenge to an active lifestyle.

Improving the Estimation of Mealtime Insulin Dose in Adults With Type 1 Diabetes

PubMed Central

Bao, Jiansong; Gilbertson, Heather R.; Gray, Robyn; Munns, Diane; Howard, Gabrielle; Petocz, Peter; Colagiuri, Stephen; Brand-Miller, Jennie C.

2011-01-01

OBJECTIVE Although carbohydrate counting is routine practice in type 1 diabetes, hyperglycemic episodes are common. A food insulin index (FII) has been developed and validated for predicting the normal insulin demand generated by mixed meals in healthy adults. We sought to compare a novel algorithm on the basis of the FII for estimating mealtime insulin dose with carbohydrate counting in adults with type 1 diabetes. RESEARCH DESIGN AND METHODS A total of 28 patients using insulin pump therapy consumed two different breakfast meals of equal energy, glycemic index, fiber, and calculated insulin demand (both FII = 60) but approximately twofold difference in carbohydrate content, in random order on three consecutive mornings. On one occasion, a carbohydrate-counting algorithm was applied to meal A (75 g carbohydrate) for determining bolus insulin dose. On the other two occasions, carbohydrate counting (about half the insulin dose as meal A) and the FII algorithm (same dose as meal A) were applied to meal B (41 g carbohydrate). A real-time continuous glucose monitor was used to assess 3-h postprandial glycemia. RESULTS Compared with carbohydrate counting, the FII algorithm significantly decreased glucose incremental area under the curve over 3 h (–52%, P = 0.013) and peak glucose excursion (–41%, P = 0.01) and improved the percentage of time within the normal blood glucose range (4–10 mmol/L) (31%, P = 0.001). There was no significant difference in the occurrence of hypoglycemia. CONCLUSIONS An insulin algorithm based on physiological insulin demand evoked by foods in healthy subjects may be a useful tool for estimating mealtime insulin dose in patients with type 1 diabetes. PMID:21949219

Intelligent pump test system based on virtual instrument

NASA Astrophysics Data System (ADS)

Ma, Jungong; Wang, Shifu; Wang, Zhanlin

2003-09-01

The intelligent pump system is the key component of the aircraft hydraulic system that can solve the problem, such as the temperature sharply increasing. As the performance of the intelligent pump directly determines that of the aircraft hydraulic system and seriously affects fly security and reliability. So it is important to test all kinds of performance parameters of intelligent pump during design and development, while the advanced, reliable and complete test equipments are the necessary instruments for achieving the goal. In this paper, the application of virtual instrument and computer network technology in aircraft intelligent pump test is presented. The composition of the hardware, software, hydraulic circuit in this system are designed and implemented.

Initiation of insulin pump therapy in children at diagnosis of type 1 diabetes resulted in improved long-term glycemic control.

PubMed

Lang, Eunice G; King, Bruce R; Miller, Malcolm N; Dunn, Sandra V; Price, Darrell A; Foskett, Deborah C

2017-02-01

Insulin pump therapy (IPT) is increasingly used in children and young people with type 1 diabetes. There are limited studies evaluating the optimal time to start IPT. The aim of this study was to determine if early initiation of IPT in children with type 1 diabetes leads to improved glycaemic control and quality of life (QOL) compared with the later introduction of IPT. There were 38 subjects in the early pump group (EPG) (age 12.6 + 4.9 yr, 23 male) and 37 in the later pump group (LPG) (age 13.1 + 4.1 yr, 19 male). Hemoglobin A1c (HbA1c), rate of severe hypoglycemia, and diabetic ketoacidosis (DKA) were collected retrospectively over a 48-month period. Eligible subjects and/or their parents completed both a Paediatric and Paediatric Diabetes-specific Quality of Life Inventory. HbA1c measurements were lower in the EPG (6.8%; 51 mmol/mol) compared to the LPG (7.9%; 63 mmol/mol), across the 48 months of the study (p < 0.0001). There was no significant difference in the rate (per patient years) of severe hypoglycaemia (0.02; 0.07) p = 0.075 between the two groups. There were no episodes of DKA in either group. There was no significant difference in QOL between the groups with both having high satisfaction rates. Initiation of IPT at diagnosis of type 1 diabetes in children resulted in consistently lower HbA1c with no apparent change in hypoglycemia, DKA, or QOL. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Power consumption analysis of pump station control systems based on fuzzy controllers with discrete terms in iThink software

NASA Astrophysics Data System (ADS)

Muravyova, E. A.; Bondarev, A. V.; Sharipov, M. I.; Galiaskarova, G. R.; Kubryak, A. I.

2018-03-01

In this article, power consumption of pumping station control systems is discussed. To study the issue, two simulation models of oil level control in the iThink software have been developed, using a frequency converter only and using a frequency converter and a fuzzy controller. A simulation of the oil-level control was carried out in a graphic form, and plots of pumps power consumption were obtained. Based on the initial and obtained data, the efficiency of the considered control systems has been compared, and also the power consumption of the systems was shown graphically using a frequency converter only and using a frequency converter and a fuzzy controller. The models analysis has shown that it is more economical and safe to use a control circuit with a frequency converter and a fuzzy controller.

Performance and safety of an integrated bihormonal artificial pancreas for fully automated glucose control at home.

PubMed

Blauw, H; van Bon, A C; Koops, R; DeVries, J H

2016-07-01

To assess the performance and safety of an integrated bihormonal artificial pancreas system consisting of one wearable device and two wireless glucose sensor transmitters during short-term daily use at home. Adult patients with type 1 diabetes using an insulin pump were invited to enrol in this randomized crossover study. Treatment with the artificial pancreas started with a day and night in the clinical research centre, followed by 3 days at home. The control period consisted of 4 days of insulin pump therapy at home with blinded continuous glucose monitoring for data collection. Days 2-4 were predefined as the analysis period, with median glucose as the primary outcome. A total of 10 patients completed the study. The median [interquartile range (IQR)] glucose level was similar for the two treatments [7.3 (7.0-7.6) mmol/l for the artificial pancreas vs. 7.7 (7.0-9.0) mmol/l for the control; p = 0.123]. The median (IQR) percentage of time spent in euglycaemia (3.9-10 mmol/l) was longer during use of the artificial pancreas [84.7 (82.2-87.8)% for the artificial pancreas vs. 68.5 (57.9-83.6)% for the control; p = 0.007]. Time in hypoglycaemia was 1.3 (0.2-3.2)% for the artificial pancreas and 2.4 (0.4-10.3)% for the control treatment (p = 0.139). Separate analysis of daytime and night-time showed that the improvements were mainly achieved during the night. The results of this pilot study suggest that our integrated artificial pancreas provides better glucose control than insulin pump therapy in patients with type 1 diabetes at home and that the treatment is safe. © 2016 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.

Abnormal cation transport in uremia. Mechanisms in adipocytes and skeletal muscle from uremic rats.

PubMed

Druml, W; Kelly, R A; May, R C; Mitch, W E

1988-04-01

The cause of the abnormal active cation transport in erythrocytes of some uremic patients is unknown. In isolated adipocytes and skeletal muscle from chronically uremic chronic renal failure rats, basal sodium pump activity was decreased by 36 and 30%, and intracellular sodium was increased by 90 and 50%, respectively, compared with pair-fed control rats; insulin-stimulated sodium pump activity was preserved in both tissues. Lower basal NaK-ATPase activity in adipocytes was due to a proportionate decline in [3H]ouabain binding, while in muscle, [3H]ouabain binding was not changed, indicating that the NaK-ATPase turnover rate was decreased. Normal muscle, but not normal adipocytes, acquired defective Na pump activity when incubated in uremic sera. Thus, the mechanism for defective active cation transport in CRF is multifactorial and tissue specific. Sodium-dependent amino acid transport in adipocytes closely paralleled diminished Na pump activity (r = 0.91), indicating the importance of this defect to abnormal cellular metabolism in uremia.

Abnormal cation transport in uremia. Mechanisms in adipocytes and skeletal muscle from uremic rats.

PubMed Central

Druml, W; Kelly, R A; May, R C; Mitch, W E

1988-01-01

The cause of the abnormal active cation transport in erythrocytes of some uremic patients is unknown. In isolated adipocytes and skeletal muscle from chronically uremic chronic renal failure rats, basal sodium pump activity was decreased by 36 and 30%, and intracellular sodium was increased by 90 and 50%, respectively, compared with pair-fed control rats; insulin-stimulated sodium pump activity was preserved in both tissues. Lower basal NaK-ATPase activity in adipocytes was due to a proportionate decline in [3H]ouabain binding, while in muscle, [3H]ouabain binding was not changed, indicating that the NaK-ATPase turnover rate was decreased. Normal muscle, but not normal adipocytes, acquired defective Na pump activity when incubated in uremic sera. Thus, the mechanism for defective active cation transport in CRF is multifactorial and tissue specific. Sodium-dependent amino acid transport in adipocytes closely paralleled diminished Na pump activity (r = 0.91), indicating the importance of this defect to abnormal cellular metabolism in uremia. PMID:2832446

Brain function monitoring during off-pump cardiac surgery: a case report

PubMed Central

Zanatta, Paolo; Bosco, Enrico; Di Pasquale, Piero; Nivedita, Agarwal; Valfrè, Carlo; Sorbara, Carlo

2008-01-01

Background Early postoperative stroke is an adverse syndrome after coronary bypass surgery. This report focuses on overcoming of cerebral ischemia as a result of haemodynamic instability during heart enucleation in off-pump procedure. Case presentation A 67 year old male patient, Caucasian race, with a body mass index of 28, had a recent non-Q posterolateral myocardial infarction one month before and recurrent instable angina. His past history includes an uncontrolled hypertension, dyslipidemia, insulin dependent diabetes mellitus, epiaortic vessel stenosis. The patient was scheduled for an off-pump procedure and monitored with bilateral somatosensory evoked potentials, whose alteration signalled the decrement of the cardiac index during operation. The somatosensory evoked potentials appeared when the blood pressure was increased with a pharmacological treatment. Conclusion During the off-pump coronary bypass surgery, a lower cardiac index, predisposes patients, with multiple stroke risk factors, to a reduction of the cerebral blood flow. Intraoperative somatosensory evoked potentials monitoring provides informations about the functional status of somatosensory cortex to reverse effects of brain ischemia. PMID:18706094

The research on flow pulsation characteristics of axial piston pump

NASA Astrophysics Data System (ADS)

Wang, Bingchao; Wang, Yulin

2017-01-01

The flow pulsation is an important factor influencing the axial piston pump performance. In this paper we implement modeling and simulation of the axial piston pump with AMESim software to explore the flow pulsation characteristics under various factors . Theory analysis shows the loading pressure, angular speed, piston numbers and the accumulator impose evident influence on the flow pulsation characteristics. This simulation and analysis can be used for reducing the flow pulsation rate via properly setting the related factors.

AZ-101 Mixer Pump Test Qualification Test Procedures (QTP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

THOMAS, W.K.

2000-01-10

Describes the Qualification test procedure for the AZ-101 Mixer Pump Data Acquisition System (DAS). The purpose of this Qualification Test Procedure (QTP) is to confirm that the AZ-101 Mixer Pump System has been properly programmed and hardware configured correctly. This QTP will test the software setpoints for the alarms and also check the wiring configuration from the SIMcart to the HMI. An Acceptance Test Procedure (ATP), similar to this QTP will be performed to test field devices and connections from the field.

Use of Commonly Available Technologies for Diabetes Information and Self-Management Among Adolescents With Type 1 Diabetes and Their Parents: A Web-Based Survey Study.

PubMed

Vaala, Sarah E; Hood, Korey K; Laffel, Lori; Kumah-Crystal, Yaa A; Lybarger, Cindy K; Mulvaney, Shelagh A

2015-12-29

For individuals with Type 1 diabetes (T1D), following a complicated daily medical regimen is critical to maintaining optimal health. Adolescents in particular struggle with regimen adherence. Commonly available technologies (eg, diabetes websites, apps) can provide diabetes-related support, yet little is known about how many adolescents with T1D use them, why they are used, or relationships between use and self-management. This study examined adolescent and parent use of 5 commonly available technologies for diabetes, including proportions who use each technology, frequency of use, and number of different technologies used for diabetes. Analyses also investigated the reasons adolescents reported for using or not using technologies for diabetes, and factors correlated with adolescents' technology use. Finally, this study examined relationships between the type and number of technologies adolescents use for diabetes and their self-management and glycemic control. Adolescents (12-17 years) and their parents (N=174 pairs), recruited from a pediatric diabetes clinic (n=134) and the Children with Diabetes community website (n=40), participated in this Web-based survey study. Glycosylated hemoglobin (A1C) values were obtained from medical records for pediatric clinic patients. Adolescents reported their use of 5 commonly available technologies for diabetes (ie, social networking, diabetes websites, mobile diabetes apps, text messaging, and glucometer/insulin pump software), reasons for use, and self-management behavior (Self-Care Inventory-Revised, SCI-R). Most adolescents and parents used at least one of the 5 technologies for diabetes. Among adolescents, the most commonly used technology for diabetes was text messaging (53%), and the least commonly used was diabetes websites (25%). Most adolescents who used diabetes apps, text messaging, or pump/glucometer software did so more frequently (≥2 times per week), compared to social networking and website use (≤1 time per week). The demographic, clinical, and parent-technology use factors related to adolescents' technology use varied by technology. Adolescents who used social networking, websites, or pump/glucometer software for diabetes had better self-management behavior (SCI-R scores: beta=.18, P=.02; beta=.15, P=.046; beta=.15, P=.04, respectively), as did those who used several technologies for diabetes (beta=.23, P=.003). However, use of diabetes websites was related to poorer glycemic control (A1C: beta=.18, P=.01). Adolescents with T1D may be drawn to different technologies for different purposes, as individual technologies likely offer differing forms of support for diabetes self-management (eg, tracking blood glucose or aiding problem solving). Findings suggest that technologies that are especially useful for adolescents' diabetes problem solving may be particularly beneficial for their self-management. Additional research should examine relationships between the nature of technology use and adolescents' T1D self-management over time.

Use of Commonly Available Technologies for Diabetes Information and Self-Management Among Adolescents With Type 1 Diabetes and Their Parents: A Web-Based Survey Study

PubMed Central

Vaala, Sarah E; Hood, Korey K; Laffel, Lori; Kumah-Crystal, Yaa A; Lybarger, Cindy K

2015-01-01

Background For individuals with Type 1 diabetes (T1D), following a complicated daily medical regimen is critical to maintaining optimal health. Adolescents in particular struggle with regimen adherence. Commonly available technologies (eg, diabetes websites, apps) can provide diabetes-related support, yet little is known about how many adolescents with T1D use them, why they are used, or relationships between use and self-management. Objective This study examined adolescent and parent use of 5 commonly available technologies for diabetes, including proportions who use each technology, frequency of use, and number of different technologies used for diabetes. Analyses also investigated the reasons adolescents reported for using or not using technologies for diabetes, and factors correlated with adolescents’ technology use. Finally, this study examined relationships between the type and number of technologies adolescents use for diabetes and their self-management and glycemic control. Methods Adolescents (12-17 years) and their parents (N=174 pairs), recruited from a pediatric diabetes clinic (n=134) and the Children with Diabetes community website (n=40), participated in this Web-based survey study. Glycosylated hemoglobin (A1C) values were obtained from medical records for pediatric clinic patients. Adolescents reported their use of 5 commonly available technologies for diabetes (ie, social networking, diabetes websites, mobile diabetes apps, text messaging, and glucometer/insulin pump software), reasons for use, and self-management behavior (Self-Care Inventory-Revised, SCI-R). Results Most adolescents and parents used at least one of the 5 technologies for diabetes. Among adolescents, the most commonly used technology for diabetes was text messaging (53%), and the least commonly used was diabetes websites (25%). Most adolescents who used diabetes apps, text messaging, or pump/glucometer software did so more frequently (≥2 times per week), compared to social networking and website use (≤1 time per week). The demographic, clinical, and parent-technology use factors related to adolescents’ technology use varied by technology. Adolescents who used social networking, websites, or pump/glucometer software for diabetes had better self-management behavior (SCI-R scores: beta=.18, P=.02; beta=.15, P=.046; beta=.15, P=.04, respectively), as did those who used several technologies for diabetes (beta=.23, P=.003). However, use of diabetes websites was related to poorer glycemic control (A1C: beta=.18, P=.01). Conclusions Adolescents with T1D may be drawn to different technologies for different purposes, as individual technologies likely offer differing forms of support for diabetes self-management (eg, tracking blood glucose or aiding problem solving). Findings suggest that technologies that are especially useful for adolescents’ diabetes problem solving may be particularly beneficial for their self-management. Additional research should examine relationships between the nature of technology use and adolescents’ T1D self-management over time. PMID:26715191

Vitamin C deficiency aggravates tumor necrosis factor α-induced insulin resistance.

PubMed

Qing, Zhou; Xiao-Hui, Wu; Xi-Mei, Wu; Chao-Chun, Zou

2018-06-15

Chronic low-grade inflammation plays a major role in the development of insulin resistance. The potential role and underlying mechanism of vitamin C, an antioxidant and anti-inflammatory agent, was investigated in tumor necrosis factor-α (TNF-α)-induced insulin resistance. Gulonolactone oxidase knockout (Gulo -/- ) mice genetically unable to synthesize vitamin C were used to induce insulin resistance by continuously pumping small doses of TNF-α for seven days, and human liver hepatocellular carcinoma cells (HepG2 cells) were used to induce insulin resistance by treatment with TNF-α. Vitamin C deficiency aggravated TNF-α-induced insulin resistance in Gulo -/- mice, resulting in worse glucose tolerance test (GTT) results, higher fasting plasma insulin level, and the inactivation of the protein kinase B (AKT)/glycogen synthase kinase-3β (GSK3β) pathway in the liver. Vitamin C deficiency also worsened liver lipid accumulation and inflammation in TNF-α-treated Gulo -/- mice. In HepG2 cells, vitamin C reversed the TNF-α-induced reduction of glucose uptake and glycogen synthesis, which were mediated by increasing GLUT2 levels and the activation of the insulin receptor substrate (IRS-1)/AKT/GSK3β pathway. Furthermore, vitamin C inhibited the TNF-α-induced activation of not only the mitogen-activated protein kinase (MAPKs), but also nuclear factor-kappa B (NF-κB) signaling. Taken together, vitamin C is essential for preventing and improving insulin resistance, and the supplementing with vitamin C may be an effective therapeutic intervention for metabolic disorders. Copyright © 2018 Elsevier B.V. All rights reserved.

Thermodynamic performance of multi-stage gradational lead screw vacuum pump

NASA Astrophysics Data System (ADS)

Zhao, Fan; Zhang, Shiwei; Sun, Kun; Zhang, Zhijun

2018-02-01

As a kind of dry mechanical vacuum pump, the twin-screw vacuum pump has an outstanding pumping performance during operation, widely used in the semiconductor industry. Compared with the constant lead screw (CLS) vacuum pump, the gradational lead screw (GLS) vacuum pump is more popularly applied in recent years. Nevertheless, not many comparative studies on the thermodynamic performance of GLS vacuum pump can be found in the literature. Our study focuses on one type of GLS vacuum pump, the multi-stage gradational lead screw (MGLS) vacuum pump, gives a detailed description of its construction and illustrates it with the drawing. Based on the structural analysis, the thermodynamic procedure is divided into four distinctive processes, including sucking process, transferring (compressing) process, backlashing process and exhausting process. The internal mechanism of each process is qualitatively illustrated and the mathematical expressions of seven thermodynamic parameters are given under the ideal situation. The performance curves of MGLS vacuum pump are plotted by MATLAB software and compared with those of the CLS vacuum pump in the same case. The results can well explain why the MGLS vacuum pump has more favorable pumping performance than the CLS vacuum pump in saving energy, reducing noise and heat dissipation.

Progress of artificial pancreas devices towards clinical use: the first outpatient studies.

PubMed

Russell, Steven J

2015-04-01

This article describes recent progress in the automated control of glycemia in type 1 diabetes with artificial pancreas devices that combine continuous glucose monitoring with automated decision-making and insulin delivery. After a gestation period of closely supervised feasibility studies in research centers, the last 2 years have seen publication of studies testing these devices in outpatient environments, and many more such studies are ongoing. The most basic form of automation, suspension of insulin delivery for actual or predicted hypoglycemia, has been shown to be effective and well tolerated, and a first-generation device has actually reached the market. Artificial pancreas devices that actively dose insulin fall into two categories, those that dose insulin alone and those that also use glucagon to prevent and treat hypoglycemia (bihormonal artificial pancreas). Initial outpatient clinical trials have shown that both strategies can improve glycemic management in comparison with patient-controlled insulin pump therapy, but only the bihormonal strategy has been tested without restrictions on exercise. Artificial pancreas technology has the potential to reduce acute and chronic complications of diabetes and mitigate the burden of diabetes self-management. Successful outpatient studies bring these technologies one step closer to availability for patients.

Diabetic ketoacidosis producing extreme hyperkalemia in a patient with type 1 diabetes on hemodialysis.

PubMed

Yamada, Hodaka; Funazaki, Shunsuke; Kakei, Masafumi; Hara, Kazuo; Ishikawa, San-E

2017-01-01

Diabetic ketoacidosis (DKA) is a critical complication of type 1 diabetes associated with water and electrolyte disorders. Here, we report a case of DKA with extreme hyperkalemia (9.0 mEq/L) in a patient with type 1 diabetes on hemodialysis. He had a left frontal cerebral infarction resulting in inability to manage his continuous subcutaneous insulin infusion pump. Electrocardiography showed typical changes of hyperkalemia, including absent P waves, prolonged QRS interval and tented T waves. There was no evidence of total body water deficit. After starting insulin and rapid hemodialysis, the serum potassium level was normalized. Although DKA may present with hypokalemia, rapid hemodialysis may be necessary to resolve severe hyperkalemia in a patient with renal failure. Patients with type 1 diabetes on hemodialysis may develop ketoacidosis because of discontinuation of insulin treatment.Patients on hemodialysis who develop ketoacidosis may have hyperkalemia because of anuria.Absolute insulin deficit alters potassium distribution between the intracellular and extracellular space, and anuria abolishes urinary excretion of potassium.Rapid hemodialysis along with intensive insulin therapy can improve hyperkalemia, while fluid infusions may worsen heart failure in patients with ketoacidosis who routinely require hemodialysis.

Evaluation of rotor axial vibrations in a turbo pump unit equipped with an automatic unloading machine

NASA Astrophysics Data System (ADS)

Martsynkovskyy, V. A.; Deineka, A.; Kovalenko, V.

2017-08-01

The article presents forced axial vibrations of the rotor with an automatic unloading machine in an oxidizer pump. A feature of the design is the use in the autoloading system of slotted throttles with mutually inverse throttling. Their conductivity is determined by a numerical experiment in the ANSYS CFX software package.

Quantification of Abdominal Fat in Obese and Healthy Adolescents Using 3 Tesla Magnetic Resonance Imaging and Free Software for Image Analysis.

PubMed

Eloi, Juliana Cristina; Epifanio, Matias; de Gonçalves, Marília Maia; Pellicioli, Augusto; Vieira, Patricia Froelich Giora; Dias, Henrique Bregolin; Bruscato, Neide; Soder, Ricardo Bernardi; Santana, João Carlos Batista; Mouzaki, Marialena; Baldisserotto, Matteo

2017-01-01

Computed tomography, which uses ionizing radiation and expensive software packages for analysis of scans, can be used to quantify abdominal fat. The objective of this study is to measure abdominal fat with 3T MRI using free software for image analysis and to correlate these findings with anthropometric and laboratory parameters in adolescents. This prospective observational study included 24 overweight/obese and 33 healthy adolescents (mean age 16.55 years). All participants underwent abdominal MRI exams. Visceral and subcutaneous fat area and percentage were correlated with anthropometric parameters, lipid profile, glucose metabolism, and insulin resistance. Student's t test and Mann-Whitney's test was applied. Pearson's chi-square test was used to compare proportions. To determine associations Pearson's linear correlation or Spearman's correlation were used. In both groups, waist circumference (WC) was associated with visceral fat area (P = 0.001 and P = 0.01 respectively), and triglycerides were associated with fat percentage (P = 0.046 and P = 0.071 respectively). In obese individuals, total cholesterol/HDL ratio was associated with visceral fat area (P = 0.03) and percentage (P = 0.09), and insulin and HOMA-IR were associated with visceral fat area (P = 0.001) and percentage (P = 0.005). 3T MRI can provide reliable and good quality images for quantification of visceral and subcutaneous fat by using a free software package. The results demonstrate that WC is a good predictor of visceral fat in obese adolescents and visceral fat area is associated with total cholesterol/HDL ratio, insulin and HOMA-IR.

Usability of Medical Devices for Patients With Diabetes Who Are Visually Impaired or Blind.

PubMed

Heinemann, Lutz; Drossel, Diana; Freckmann, Guido; Kulzer, Bernhard

2016-11-01

The estimation is that every third to fourth patient with diabetes suffers from some degree of diabetic retinopathy. Medical products for insulin administration (such as insulin pens and pumps) or glucose monitoring not optimized to the needs of these patients' represent a high barrier for optimal diabetes therapy in daily practice. To date, the number of devices suitable for visually impaired and blind patients with diabetes is scarce. This manuscript outlines the specific needs of this patient group with regard to systems for insulin administration, blood glucose measurement, and continuous glucose monitoring. We see the clear need for a policy requirement for manufacturers to provide accessible/user friendly technical aids for visually impaired and blind patients with diabetes. This would represent an important step toward improving the situation for this impressively large patient group. © 2016 Diabetes Technology Society.

Fucosterol activates the insulin signaling pathway in insulin resistant HepG2 cells via inhibiting PTP1B.

PubMed

Jung, Hyun Ah; Bhakta, Himanshu Kumar; Min, Byung-Sun; Choi, Jae Sue

2016-10-01

Insulin resistance is a characteristic feature of type 2 diabetes mellitus (T2DM) and is characterized by defects in insulin signaling. This study investigated the modulatory effects of fucosterol on the insulin signaling pathway in insulin-resistant HepG2 cells by inhibiting protein tyrosine phosphatase 1B (PTP1B). In addition, molecular docking simulation studies were performed to predict binding energies, the specific binding site of fucosterol to PTP1B, and to identify interacting residues using Autodock 4.2 software. Glucose uptake was determined using a fluorescent D-glucose analogue and the glucose tracer 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxyglucose, and the signaling pathway was detected by Western blot analysis. We found that fucosterol enhanced insulin-provoked glucose uptake and conjointly decreased PTP1B expression level in insulin-resistant HepG2 cells. Moreover, fucosterol significantly reduced insulin-stimulated serine (Ser307) phosphorylation of insulin receptor substrate 1 (IRS1) and increased phosphorylation of Akt, phosphatidylinositol-3-kinase, and extracellular signal- regulated kinase 1 at concentrations of 12.5, 25, and 50 µM in insulin-resistant HepG2 cells. Fucosterol inhibited caspase-3 activation and nuclear factor kappa B in insulin-resistant hepatocytes. These results suggest that fucosterol stimulates glucose uptake and improves insulin resistance by downregulating expression of PTP1B and activating the insulin signaling pathway. Thus, fucosterol has potential for development as an anti-diabetic agent.

Unique Challenges of Type 1 Diabetes in the Preschool Population.

PubMed

Coshway, Loyal K; Hoffman, Robert P

2017-01-01

Extremely young children aged ≤6 years old represent a unique population among patients with type 1 diabetes in terms of glycemic variation, diabetes management and complications. We describe distinct features of diabetes care and outcomes in preschool age children. We searched PubMed, Google Scholar, and authors' bibliographies in order to extract articles specific to type 1 diabetes in preschool age children. The preschool age group is beset by many challenges to diabetes care, including more frequent hypo- and hyperglycemia, hypoglycemia unawareness, decreased residual beta cell function, and greater long-term neurocognitive effects from severe hypoglycemia and chronic hyperglycemia. Randomized controlled trials show that equally good metabolic control can be obtained with multiple daily injections or an insulin pump. Several non-randomized trials, including an 8 year longitudinal study, show lower hemoglobin A1C and decreased hypoglycemia on insulin pumps. Sensor augmented pump therapy resulted in superior A1C as long as sensors were used regularly. In contrast to adults, continuous glucose monitoring has little to no impact on A1C, although parents appreciate the improved monitoring for hypoglycemia. Children with onset of diabetes prior to age 5 are at risk for younger onset of microalbuminuria, however do not develop earlier onset retinopathy than children diagnosed after 5 years. Both severe hypoglycemia and chronic hyperglycemia have negative impact on neurocognition. Special knowledge about this young population is helpful for practitioners and parents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Combining Basal–Bolus Insulin Infusion for Tight Postprandial Glucose Control: An in Silico Evaluation in Adults, Children, and Adolescents

PubMed Central

Revert, Ana; Rossetti, Paolo; Calm, Remei; Vehí, Josep; Bondia, Jorge

2010-01-01

Background Achieving good postprandial glycemic control, without triggering hypoglycemia events, is a challenge of treatment strategies for type 1 diabetes subjects. Continuous subcutaneous insulin infusion, the gold standard of therapy, is based on heuristic adjustments of both basal and prandial insulin. Some tools, such as bolus calculators, are available to aid patients in selecting a meal-related insulin dose. However, they are still based on empiric parameters such as the insulin-to-carbohydrate ratio and on the physicians’ and patients’ ability to fit bolus mode to meal composition. Method In this article, a nonheuristic method for assessment of prandial insulin administration is presented and evaluated. An algorithm based on set inversion via interval analysis is used to coordinate basal and bolus insulin infusions to deal with postprandial glucose excursions. The evaluation is carried out through an in silico study using the 30 virtual patients available in the educational version of the Food and Drug Administration-accepted University of Virginia simulator. Results obtained using the standard bolus strategy and different coordinated basal–bolus solutions provided by the algorithm are compared. Results Coordinated basal–bolus solutions improve postprandial glucose performance in most cases, mainly in terms of reducing hypoglycemia risk, but also increasing the percentage of time in normoglycemia. Moreover, glycemic variability is reduced considerably by using these innovative solutions. Conclusions The algorithm presented here is a robust nonheuristic alternative to deal with postprandial glycemic control. It is shown as a powerful tool that could be integrated in future smart insulin pumps. PMID:21129338

Prevention of Hypoglycemia during Exercise in Children with Type 1 Diabetes by Suspending Basal Insulin

PubMed Central

2006-01-01

Background Strategies for preventing hypoglycemia during exercise in children with T1D have not been well studied. DirecNet conducted a study to determine whether stopping basal insulin could reduce the frequency of hypoglycemia occurring during exercise. Methods Using a randomized, crossover design, 49 children 8–17y with T1D on insulin pump therapy were studied during structured exercise sessions on two days. On one day basal insulin was stopped during exercise and on the other day it was continued. Each exercise session, performed from approximately 4–5 p.m., consisted of four 15-minute treadmill cycles at a target heart rate of 140 beats/minute (interspersed with three 5-minute rest breaks over 75 minutes) followed by a 45 minute observation period. Frequently sampled glucose concentrations (measured in the DirecNet Central Laboratory) were measured prior to, during, and following the exercise. Results Hypoglycemia (≤70 mg/dL) during exercise occurred less frequently when the basal insulin was discontinued than when it was continued (16% vs. 43%; P=0.003). Hyperglycemia (increase from baseline of ≥20% to ≥200 mg/dL) 45 minutes after the completion of exercise was more frequent without basal insulin (27% vs. 4%; P=0.002). There were no cases of abnormal blood ketone levels. Conclusion Discontinuing basal insulin during exercise is an effective strategy for reducing hypoglycemia in children with T1D, but the risk of hyperglycemia is increased. PMID:17003293

Glucose acutely decreases pH of secretory granules in mouse pancreatic islets. Mechanisms and influence on insulin secretion.

PubMed

Stiernet, Patrick; Guiot, Yves; Gilon, Patrick; Henquin, Jean-Claude

2006-08-04

Glucose-induced insulin secretion requires a rise in beta-cell cytosolic Ca2+ ([Ca2+]c) that triggers exocytosis and a mechanistically unexplained amplification of the action of [Ca2+]c. Insulin granules are kept acidic by luminal pumping of protons with simultaneous Cl- uptake to maintain electroneutrality. Experiments using patched, dialyzed beta-cells prompted the suggestion that acute granule acidification by glucose underlies amplification of insulin secretion. However, others found glucose to increase granular pH in intact islets. In this study, we measured islet granular pH with Lysosensor DND-160, a fluorescent dye that permits ratiometric determination of pH < 6 in acidic compartments. Stimulation of mouse islets with glucose reversibly decreased granular pH by mechanisms that are dependent on metabolism and Cl- ions but independent of changes in [Ca2+]c and protein kinase A or C activity. Granular pH was increased by concanamycin (blocker of the vesicular type H+-ATPase) > methylamine (weak base) > Cl- omission. Concanamycin and methylamine did not alter glucose-induced [Ca2+]c increase in islets but strongly inhibited the two phases of insulin secretion. Omission of Cl- did not affect the first phase but decreased the second phase of both [Ca2+]c and insulin responses. Neither experimental condition affected the [Ca2+]c rise induced by 30 mM KCl, but the insulin responses were inhibited by concanamycin > methylamine and not affected by Cl- omission. The amplification of insulin secretion by glucose was not suppressed. We conclude that an acidic granular pH is important for insulin secretion but that the acute further acidification produced by glucose is not essential for the augmentation of secretion via the amplifying pathway.

Conversion from insulin glargine U-100 to insulin glargine U-300 or insulin degludec and the impact on dosage requirements.

PubMed

Pearson, Scott M; Trujillo, Jennifer M

2018-04-01

We wanted to determine whether basal insulin requirements change when patients transition from insulin glargine U-100 (Gla-100) to insulin glargine U-300 (Gla-300) or insulin degludec. This study involved subjects seen in the University of Colorado Health Endocrine Clinic who were transitioned from Gla-100 to either Gla-300 ( n = 95) or insulin degludec ( n = 39). The primary outcome was the difference between baseline Gla-100 dose and dose of Gla-300 or insulin degludec prescribed after first follow-up visit within 1-12 months. Secondary outcomes included changes in glycemic control and empiric dose conversion from Gla-100 to Gla-300 or insulin degludec on the day of transition. Wilcoxon rank sum tests evaluated changes in insulin doses, and paired t tests assessed changes in glycemic control using GraphPad statistical software. Median daily basal insulin dose increased for individuals transitioned from Gla-100 to Gla-300 from 30 [19-60 interquartile range (IQR)] units at baseline to 34.5 (19-70 IQR) units after follow up ( p = 0.01). For patients transitioned to insulin degludec, dose changes from baseline to follow up were not significantly different ( p = 0.56). At the time of transition, the prescribed dose of Gla-300 or insulin degludec did not significantly differ from the previous dose of Gla-100 ( p = 0.73 and 0.28, respectively), indicating that empiric dose adjustments were not routinely prescribed. Patients who transitioned from Gla-100 to Gla-300 had increased basal insulin requirements between visits, while basal insulin requirements for those transitioned from Gla-100 to insulin degludec were not significantly different.

Conversion from insulin glargine U-100 to insulin glargine U-300 or insulin degludec and the impact on dosage requirements

PubMed Central

Trujillo, Jennifer M.

2018-01-01

Background: We wanted to determine whether basal insulin requirements change when patients transition from insulin glargine U-100 (Gla-100) to insulin glargine U-300 (Gla-300) or insulin degludec. Methods: This study involved subjects seen in the University of Colorado Health Endocrine Clinic who were transitioned from Gla-100 to either Gla-300 (n = 95) or insulin degludec (n = 39). The primary outcome was the difference between baseline Gla-100 dose and dose of Gla-300 or insulin degludec prescribed after first follow-up visit within 1–12 months. Secondary outcomes included changes in glycemic control and empiric dose conversion from Gla-100 to Gla-300 or insulin degludec on the day of transition. Wilcoxon rank sum tests evaluated changes in insulin doses, and paired t tests assessed changes in glycemic control using GraphPad statistical software. Results: Median daily basal insulin dose increased for individuals transitioned from Gla-100 to Gla-300 from 30 [19–60 interquartile range (IQR)] units at baseline to 34.5 (19–70 IQR) units after follow up (p = 0.01). For patients transitioned to insulin degludec, dose changes from baseline to follow up were not significantly different (p = 0.56). At the time of transition, the prescribed dose of Gla-300 or insulin degludec did not significantly differ from the previous dose of Gla-100 (p = 0.73 and 0.28, respectively), indicating that empiric dose adjustments were not routinely prescribed. Conclusions: Patients who transitioned from Gla-100 to Gla-300 had increased basal insulin requirements between visits, while basal insulin requirements for those transitioned from Gla-100 to insulin degludec were not significantly different. PMID:29619208

Modeling and performance improvement of the constant power regulator systems in variable displacement axial piston pump.

PubMed

Park, Sung Hwan; Lee, Ji Min; Kim, Jong Shik

2013-01-01

An irregular performance of a mechanical-type constant power regulator is considered. In order to find the cause of an irregular discharge flow at the cut-off pressure area, modeling and numerical simulations are performed to observe dynamic behavior of internal parts of the constant power regulator system for a swashplate-type axial piston pump. The commercial numerical simulation software AMESim is applied to model the mechanical-type regulator with hydraulic pump and simulate the performance of it. The validity of the simulation model of the constant power regulator system is verified by comparing simulation results with experiments. In order to find the cause of the irregular performance of the mechanical-type constant power regulator system, the behavior of main components such as the spool, sleeve, and counterbalance piston is investigated using computer simulation. The shape modification of the counterbalance piston is proposed to improve the undesirable performance of the mechanical-type constant power regulator. The performance improvement is verified by computer simulation using AMESim software.

Insulin activation of plasma non-esterified fatty acid uptake in metabolic syndrome

PubMed Central

Ramos-Roman, Maria A.; Lapidot, Smadar A.; Phair, Robert D.; Parks, Elizabeth J.

2012-01-01

Objectives Insulin control of fatty acid metabolism has long been deemed dominated by suppression of adipose lipolysis. This study’s goal was to test the hypothesis that this single role of insulin is insufficient to explain observed fatty acid dynamics. Methods and Results Fatty acid kinetics were measured during a meal-tolerance test and insulin sensitivity assessed by IVGTT in overweight human subjects (n=15, BMI 35.8 ± 7.1 kg/m2). Non-steady state tracer kinetic models were formulated and tested using ProcessDB© software. Suppression of adipose release alone could not account for NEFA concentration changes postprandially, but when combined with insulin activation of fatty acid uptake was consistent with the NEFA data. The observed insulin Km for NEFA uptake was inversely correlated with both insulin sensitivity of glucose uptake (IVGTT Si) (r=−0.626, P=0.01), and whole body fat oxidation after the meal (r=−0.538, P=0.05). Conclusions These results support insulin regulation of fatty acid turnover by both release and uptake mechanisms. Activation of fatty acid uptake is consistent with the human data, has mechanistic precedent in cell culture, and highlights a new potential target for therapies aimed at improving the control of fatty acid metabolism in insulin-resistant disease states. PMID:22723441

Incorporating a Generic Model of Subcutaneous Insulin Absorption into the AIDA v4 Diabetes Simulator: 1. A Prospective Collaborative Development Plan

PubMed Central

Lehmann, Eldon D.; Tarín, Cristina; Bondia, Jorge; Teufel, Edgar; Deutsch, Tibor

2007-01-01

Introduction AIDA v4 is an interactive educational diabetes simulator that has been made available, for over a decade, without charge via the Internet. The software is currently freely accessible at http://www.2aida.org. This report sets out a collaborative development plan to enhance the program with a new model of subcutaneous insulin absorption, which permits the simulation of rapidly acting and very long-acting insulin analogues, as well as insulin injection doses larger than 40 units. Methods A novel, generic, physiological subcutaneous insulin absorption model is overviewed and a methodology is proposed by which this can be substituted in place of the previously adopted insulin absorption model utilized within AIDA v4.3a. Apart from this substitution it is proposed to retain the existing model of the glucoregulatory system currently used in AIDA v4.3a. Results Initial simulation results based on bench testing of this approach using MATLAB are presented for the exogenous insulin flow profile (Iex) following subcutaneous injections of a rapidly acting insulin analogue, a short-acting (regular) insulin preparation, intermediate-acting insulins (both Semilente and neutral protamine Hagedorn types), and a very long-acting insulin analogue. Discussion It is proposed to implement this collaborative development plan—first by bench testing the approach in MATLAB and then by integrating the generic subcutaneous insulin absorption Iex model into the AIDA simulator in Pascal. The aim is to provide enhanced functionality and educational simulations of regimens utilizing novel insulin analogues, as well as injections larger than 40 units of insulin. PMID:19885100

Flexibility of rapid-acting insulin analogues in children and adolescents with diabetes mellitus.

PubMed

Danne, Thomas

2007-01-01

Every year, approximately 70,000 children aged<15 years develop type 1 diabetes mellitus (DM) worldwide. Achieving glycosylated hemoglobin control is a very important aim, but quality-of-life concerns for the child and the family should also have high priority in the management of pediatric DM. This review outlines some of the issues involved in treating type 1 DM in children and adolescents, as well as the use of rapid-acting insulin analogues in basal-bolus therapy and continuous subcutaneous insulin infusion pumps. This review article was based on a presentation at a satellite symposium entitled "Realising the Value of Modern Insulins: Reaching Further with Rapid-Acting Insulin Analogues "that was convened during the XIXth World Diabetes Congress, December 3, 2006, in Cape Town, South Africa. Treating children and adolescents with DM is a challenge that should not be ignored. Furthermore, DM in children is quite different from that in adults. Numerous factors have to be taken into account when evaluating treatment for children with DM in comparison with treatment for adult DM: sleep patterns; unpredictable activities, especially eating behaviors; limited size of injection sites, making it difficult to rotate injections; higher insulin sensitivity; and frequent infectious diseases. In addition, achieving normal psychosocial development may be just as important as achieving strict metabolic control in this population. Rapid-acting insulin analogues can be used effectively in these individuals with type 1 DM. The pharmacokinetic profile of insulin aspart suggests that it is suitable for flexible mealtime administration in children and adolescents. Indeed, clinical studies in children and adolescents have shown the efficacy and tolerability of postprandial administration of insulin aspart, particularly in comparison with soluble human insulin. Postprandial administration of insulin aspart, compared with preprandial soluble human insulin, has also been studied in very young children (aged 2-6 years); similar metabolic control and increased parent preference for insulin aspart were reported. Rapid-acting insulin analogues in children and adolescents with type 1 DM are effective and well tolerated; they can be injected postprandially, and this is a reliable option that can be recommended to patients and their families.

Childhood diabetes mellitus: recent advances & future prospects.

PubMed

Dejkhamron, Prapai; Menon, Ram K; Sperling, Mark A

2007-03-01

Diabetes mellitus (DM) is a metabolic disease characterized by absolute or relative insulin deficiency. Absolute deficiency of insulin most commonly results from an autoimmune destruction of insulin producing cells in the pancreas and in general, the term Type 1 DM (T1DM) is used to denote childhood diabetes associated with autoimmunity and absolute insulin deficiency. The term Type 2 DM (T2DM) is used to denote diabetes resulting from a relative deficiency of insulin when insulin secretion is inadequate to overcome co-existent resistance to insulin action on carbohydrate, protein or fat metabolism; T2DM is most commonly associated with the prototypic insulin resistant state of obesity. In the western hemisphere DM is one of the most prevalent chronic diseases in childhood, whereas the incidence of T1DM in developing countries is significantly less than that in the western hemisphere. Epidemiological studies indicate that there is gradual but steady increase in the incidence of both T1DM and T2DM in both developed and developing countries. This review provides an overview of the major advances in our understanding of the aetiology, pathogenesis, and clinical management of DM in children with the focus being on T1DM. Genetic predisposition, environmental causes, and emerging concepts of the pathogenesis of T1DM such as the accelerator hypothesis are discussed. The goals of treating a child with DM are to achieve normal growth and development with prevention of acute and chronic complications of DM. These goals are achieved by co-ordinated care delivered by a multidisciplinary team focusing on insulin administrations, glucose monitoring, meal planning, and screening for complications. Newer insulin analogues ("designer" insulin) and automated methods of delivery via programmable pumps have revolutionized the care of the child with diabetes. Though T1DM cannot yet be prevented, ongoing trials and strategies aimed at modulating the autoimmune response and the burgeoning science of embryonic stem cell biology, and isolating and propagating islet cell progenitor cells are discussed in this review.

Model-based engineering for medical-device software.

PubMed

Ray, Arnab; Jetley, Raoul; Jones, Paul L; Zhang, Yi

2010-01-01

This paper demonstrates the benefits of adopting model-based design techniques for engineering medical device software. By using a patient-controlled analgesic (PCA) infusion pump as a candidate medical device, the authors show how using models to capture design information allows for i) fast and efficient construction of executable device prototypes ii) creation of a standard, reusable baseline software architecture for a particular device family, iii) formal verification of the design against safety requirements, and iv) creation of a safety framework that reduces verification costs for future versions of the device software. 1.

Continuous subcutaneous insulin infusion therapy and multiple daily insulin injections in type 1 diabetes mellitus: a comparative overview and future horizons.

PubMed

Thabit, Hood; Hovorka, Roman

2016-01-01

Continuous subcutaneous insulin infusion (CSII) therapy is currently accepted as a treatment strategy for type 1 diabetes. Transition from multiple daily injection therapy (MDI; including basal-bolus regimens) to CSII is based on expectations of better metabolic control and fewer hypoglycaemic events. Evidence to date has not been always conclusive. Evidence for CSII and MDI in terms of glycaemic control, hypoglycaemia and psychosocial outcomes is reviewed in the adult and paediatric population with type 1 diabetes. Findings from studies on threshold-based insulin pump suspension and predictive low glucose management (PLGM) are outlined. Limitations of current CSII application and future technological developments are discussed. Glycaemic control and quality of life (QOL) may be improved by CSII compared to MDI depending on baseline HbA1c and hypoglycaemia rates. Future studies are expected to provide evidence on clinical and cost effectiveness in those who will benefit the most. Training, structured education and support are important to benefit from CSII. Novel technological approaches linking continuous glucose monitoring (CGM) and CSII may help mitigate against frequent hypoglycaemia in those at risk. Development of glucose-responsive automated closed-loop insulin delivery systems may reduce the burden of disease management and improve outcomes in type 1 diabetes.

Heat pump concepts for nZEB Technology developments, design tools and testing of heat pump systems for nZEB in the USA: Country report IEA HPT Annex 40 Task 2, Task 3 and Task 4 of the USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxter, Van D.; Payne, W. Vance; Ling, Jiazhen

The IEA HPT Annex 40 "Heat pump concepts for Nearly Zero Energy Buildings" deals with the application of heat pumps as a core component of the HVAC system for Nearly or Net Zero energy buildings (nZEB). This report covers Task 2 on the system comparison and optimisation and Task 3 dedicated to the development of adapted technologies for nZEB and field monitoring results of heat pump systems in nZEB. In the US team three institutions are involved and have worked on the following projects: The Oak Ridge National Laboratory (ORNL) will summarize development activities through the field demonstration stage formore » several integrated heat pump (IHP) systems electric ground-source (GS-IHP) and air-source (AS-IHP) versions and an engine driven AS-IHP version. The first commercial GS-IHP product was just introduced to the market in December 2012. This work is a contribution to Task 3 of the Annex. The University of Maryland will contribute a software development project to Task 2 of the Annex. The software ThermCom evaluates occupied space thermal comfort conditions accounting for all radiative and convective heat transfer effects as well as local air properties. The National Institute of Standards and Technology (NIST) is working on a field study effort on the NIST Net Zero Energy Residential Test Facility (NZERTF). This residential building was constructed on the NIST campus and officially opened in summer 2013. During the first year, between July 2013 and June 2014, baseline performance of the NZERTF was monitored under a simulated occupancy protocol. The house was equipped with an air-to-air heat pump which included a dedicated dehumidification operating mode. Outdoor conditions, internal loads and modes of heat pump operation were monitored. Field study results with respect to heat pump operation will be reported and recommendations on heat pump optimization for a net zero energy building will be provided. This work is a contribution to Task 3 of the Annex.« less

No effect of yeast-like fungi on lipid metabolism and vascular endothelial growth factor level in children and adolescents with type 1 diabetes mellitus.

PubMed

Zorena, Katarzyna; Kowalewska, Beata; Szmigiero-Kawko, Małgorzata; Wąż, Piotr; Myśliwiec, Małgorzata

2016-12-12

The objective of the research was to investigate vascular endothelial growth factor (VEGF) levels in the context of lipid metabolism and amount of yeast-like fungi colonizing the digestive tract in children and adolescents with type 1 diabetes mellitus (T1DM). The study included 45 children with T1DM and 27 age- and sex-matched healthy control subjects. In the study sample 33 T1DM patients were administered insulin pump therapy and 12 T1DM patients were administered multiple daily injections with insulin pen devices. All T1DM patients were free of micro- and macrovascular complications. In T1DM patients and healthy controls biochemical tests were performed and measurements of yeast-like fungi colonizing the alimentary tract were conducted. Moreover all study subjects had their serum VEGF levels measured with ELISA test. The subgroup of children and adolescents with T1DM and yeast-like fungus colony number 10^ 3 CFU/g was shown statistically significantly lower HbA1c levels, and lower but not statistically significantly total cholesterol, LDL cholesterol and VEGF levels versus T1DM patients with the amount of yeast-like fungi 10^ 6 CFU/g. Moreover higher HDL levels were observed in this subgroup versus T1DM patients with the amount of yeast-like fungi 10^ 6 CFU/g although the difference was not statistically significant. Our study has shown no influence of yeast-like fungi on lipid metabolism and VEGF level in children and adolescents with T1DM. Comprehensive treatment of T1DM patients and intensive insulin therapy with help of personal insulin pumps can reduce or prevent the development of long-term diabetic complications. Further studies in this field are needed.

Automated hybrid closed-loop control with a proportional-integral-derivative based system in adolescents and adults with type 1 diabetes: individualizing settings for optimal performance.

PubMed

Ly, Trang T; Weinzimer, Stuart A; Maahs, David M; Sherr, Jennifer L; Roy, Anirban; Grosman, Benyamin; Cantwell, Martin; Kurtz, Natalie; Carria, Lori; Messer, Laurel; von Eyben, Rie; Buckingham, Bruce A

2017-08-01

Automated insulin delivery systems, utilizing a control algorithm to dose insulin based upon subcutaneous continuous glucose sensor values and insulin pump therapy, will soon be available for commercial use. The objective of this study was to determine the preliminary safety and efficacy of initialization parameters with the Medtronic hybrid closed-loop controller by comparing percentage of time in range, 70-180 mg/dL (3.9-10 mmol/L), mean glucose values, as well as percentage of time above and below target range between sensor-augmented pump therapy and hybrid closed-loop, in adults and adolescents with type 1 diabetes. We studied an initial cohort of 9 adults followed by a second cohort of 15 adolescents, using the Medtronic hybrid closed-loop system with the proportional-integral-derivative with insulin feed-back (PID-IFB) algorithm. Hybrid closed-loop was tested in supervised hotel-based studies over 4-5 days. The overall mean percentage of time in range (70-180 mg/dL, 3.9-10 mmol/L) during hybrid closed-loop was 71.8% in the adult cohort and 69.8% in the adolescent cohort. The overall percentage of time spent under 70 mg/dL (3.9 mmol/L) was 2.0% in the adult cohort and 2.5% in the adolescent cohort. Mean glucose values were 152 mg/dL (8.4 mmol/L) in the adult cohort and 153 mg/dL (8.5 mmol/L) in the adolescent cohort. Closed-loop control using the Medtronic hybrid closed-loop system enables adaptive, real-time basal rate modulation. Initializing hybrid closed-loop in clinical practice will involve individualizing initiation parameters to optimize overall glucose control. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The impact of insurance coverage and the family on pediatric diabetes management.

PubMed

Watson, Sara E; Kuhl, Evan A; Foster, Michael B; Omoruyi, Adetokunbo O; Kingery, Suzanne E; Woods, Charles; Wintergerst, Kupper A

2017-06-01

The impact of family composition on glycemic control in children with type 1 diabetes remains unclear. We sought to evaluate the relationship between health insurance coverage, family composition, and insulin management, and assess their impact on glycemic control in a pediatric type 1 diabetes population. A retrospective chart review was completed for patients seen in the Pediatric Endocrinology Clinic at the University of Louisville in 2012. The analysis included 729 patients with type 1 diabetes; 268 (37%) had public insurance while 461(63%) had private insurance. Compared with publicly insured patients, privately insured patients had higher rates of intensive insulin management with multiple daily injections (MDI) plans or pump devices (88 vs. 83.2%, p = 0.066) and lower HbA1c levels [8.57 vs. 9.39% (70 vs. 79 mmol/mol), p < 0.001]. Of the 729 patients, 243 were in single-adult homes (33%). Single-adult homes had higher HbA1c levels than two-adult homes, [9.3 vs. 8.6% (78 vs. 70 mmol/mol), p < 0.001]. Among publicly insured, there was no difference in HbA1c levels for single-adult vs. two-adult homes [9.4 (79 mmol/mol), p = 0.868]. For privately insured, patients in single-adult homes had higher HbA1c levels than peers in two-adult homes [9.2 vs. 8.4% (77 vs. 68), p < 0.001]. Insurance type and family composition have significant associative effects on glycemic control and insulin management that may be mitigated by insulin pump therapy. Identifying and addressing factors such as availability of resources, family education, and adult support and supervision, may help improve glycemic control in high-risk pediatric diabetes patients. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Resource utilization with insulin pump therapy for type 2 diabetes mellitus.

PubMed

Lynch, Peter M; Riedel, Aylin Altan; Samant, Navendu; Fan, Ying; Peoples, Tim; Levinson, Jennifer; Lee, Scott W

2010-01-01

To evaluate the effects of switching from multiple daily injection (MDI) therapy to insulin pump therapy, also called continuous subcutaneous insulin infusion (CSII), on antidiabetic drug and healthcare resource utilization. This study was a retrospective analysis of administrative claims data from a large geographically diverse health plan in the United States from January 1, 2005, through April 30, 2008. Changes in antidiabetic drug use, antidiabetic drug switching and augmentation, and healthcare utilization during the baseline period and after CSII initiation were assessed using paired t test. There were 3649 possible subjects, of whom 943 met the criteria for analysis. The mean number of antidiabetic drugs used decreased by 46% after CSII initiation, and the mean reduction in antidiabetic drug utilization was 0.67; both were statistically significant. More than one-third of subjects who were taking antidiabetic drugs before CSII initiation discontinued oral therapy after CSII initiation. The number of subjects using multiple antidiabetic drugs significantly decreased after CSII initiation by 58%, and rates of switching or augmenting significantly decreased from 42% at baseline to 25% after CSII initiation.The rates of emergency department visits and inpatient admissions significantly decreased, and the rate of ambulatory visits significantly increased. CSII was associated with significant decreases in antidiabetic drug and healthcare resource utilization, contributing to stability of care. The evidence from this study indicates that CSII should be considered as an option for patients with type 2 diabetes mellitus who are using MDI and are experiencing a high degree of antidiabetic drug and healthcare resource utilization.

Human-machine interface (HMI) report for 241-SY-101 data acquisition [and control] system (DACS) upgrade study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Truitt, R.W.

1997-10-22

This report provides an independent evaluation of information for a Windows based Human Machine Interface (HMI) to replace the existing DOS based Iconics HMI currently used in the Data Acquisition and Control System (DACS) used at Tank 241-SY-101. A fundamental reason for this evaluation is because of the difficulty of maintaining the system with obsolete, unsupported software. The DACS uses a software operator interface (Genesis for DOS HMI) that is no longer supported by its manufacturer, Iconics. In addition to its obsolescence, it is complex and difficult to train additional personnel on. The FY 1997 budget allocated $40K for phasemore » 1 of a software/hardware upgrade that would have allowed the old DOS based system to be replaced by a current Windows based system. Unfortunately, budget constraints during FY 1997 has prompted deferral of the upgrade. The upgrade needs to be performed at the earliest possible time, before other failures render the system useless. Once completed, the upgrade could alleviate other concerns: spare pump software may be able to be incorporated into the same software as the existing pump, thereby eliminating the parallel path dilemma; and the newer, less complex software should expedite training of future personnel, and in the process, require that less technical time be required to maintain the system.« less

Mold heating and cooling microprocessor conversion. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, D.P.

Conversion of the microprocessors and software for the Mold Heating and Cooling (MHAC) pump package control systems was initiated to allow required system enhancements and provide data communications capabilities with the Plastics Information and Control System (PICS). The existing microprocessor-based control systems for the pump packages use an Intel 8088-based microprocessor board with a maximum of 64 Kbytes of program memory. The requirements for the system conversion were developed, and hardware has been selected to allow maximum reuse of existing hardware and software while providing the required additional capabilities and capacity. The new hardware will incorporate an Intel 80286-based microprocessormore » board with an 80287 math coprocessor, the system includes additional memory, I/O, and RS232 communication ports.« less

Simulation of pump-turbine prototype fast mode transition for grid stability support

NASA Astrophysics Data System (ADS)

Nicolet, C.; Braun, O.; Ruchonnet, N.; Hell, J.; Béguin, A.; Avellan, F.

2017-04-01

The paper explores the additional services that Full Size Frequency Converter, FSFC, solution can provide for the case of an existing pumped storage power plant of 2x210 MW, for which conversion from fixed speed to variable speed is investigated with a focus on fast mode transition. First, reduced scale model tests experiments of fast transition of Francis pump-turbine which have been performed at the ANDRITZ HYDRO Hydraulic Laboratory in Linz Austria are presented. The tests consist of linear speed transition from pump to turbine and vice versa performed with constant guide vane opening. Then existing pumped storage power plant with pump-turbine quasi homologous to the reduced scale model is modelled using the simulation software SIMSEN considering the reservoirs, penstocks, the two Francis pump-turbines, the two downstream surge tanks, and the tailrace tunnel. For the electrical part, an FSFC configuration is considered with a detailed electrical model. The transitions from turbine to pump and vice versa are simulated, and similarities between prototype simulation results and reduced scale model experiments are highlighted.

Fluid structure interaction dynamic analysis of a mixed-flow waterjet pump

NASA Astrophysics Data System (ADS)

Pan, X. W.; Y Pan, Z.; Huang, D.; Shen, Z. H.

2013-12-01

In order to avoid resonance of a mixed-flow waterjet pump at run time and calculate the stress and deformation of the pump rotor in the flow field, a one-way fluid structure interaction method was applied to simulate the pump rotor using ANSYS CFX and ANSYS Workbench software. The natural frequencies and mode shapes of the pump rotor in the air and in the flow field were analyzed, and the stress and deformation of the impeller were obtained at different flow rates. The obtained numerical results indicated that the mode shapes were similar both in the air and in the flow field, but the pump rotor's natural frequency in the flow field was slightly smaller than that in the air; the difference of the pump rotor's natural frequency varied lightly at different flow rates, and all frequencies at different flow rates were higher than the safe frequency, the pump rotor under the effect of prestress rate did not occur resonance; The maximum stress was on the blade near the hub and the maximum deformation on the blade tip at different flow rates.

A critical review and analysis of ethical issues associated with the artificial pancreas.

PubMed

Quintal, A; Messier, V; Rabasa-Lhoret, R; Racine, E

2018-04-25

The artificial pancreas combines a hormone infusion pump with a continuous glucose monitoring device, supported by a dosing algorithm currently installed on the pump. It allows for dynamic infusions of insulin (and possibly other hormones such as glucagon) tailored to patient needs. For patients with type 1 diabetes the artificial pancreas has been shown to prevent more effectively hypoglycaemic events and hyperglycaemia than insulin pump therapy and has the potential to simplify care. However, the potential ethical issues associated with the upcoming integration of the artificial pancreas into clinical practice have not yet been discussed. Our objective was to identify and articulate ethical issues associated with artificial pancreas use for patients, healthcare professionals, industry and policymakers. We performed a literature review to identify clinical, psychosocial and technical issues raised by the artificial pancreas and subsequently analysed them through a common bioethics framework. We identified five sensitive domains of ethical issues. Patient confidentiality and safety can be jeopardized by the artificial pancreas' vulnerability to security breaches or unauthorized data sharing. Public and private coverage of the artificial pancreas could be cost-effective and warranted. Patient selection criteria need to ensure equitable access and sensitivity to patient-reported outcomes. Patient coaching and support by healthcare professionals or industry representatives could help foster realistic expectations in patients. Finally, the artificial pancreas increases the visibility of diabetes and could generate issues related to personal identity and patient agency. The timely consideration of these issues will optimize the technological development and clinical uptake of the artificial pancreas. Copyright © 2018. Published by Elsevier Masson SAS.

Quality of life and technology: impact on children and families with diabetes.

PubMed

Hirose, Masakazu; Beverly, Elizabeth A; Weinger, Katie

2012-12-01

Ensuring quality of life (QOL) while maintaining glycemic control within targets is an important challenge in type 1 and type 2 diabetes treatment. For children with diabetes, QOL includes enjoying meals, feeling safe in school, and perceiving positive, supportive relationships with parents, siblings, and friends. Yet many treatment-related and psychosocial barriers can interfere with a child's QOL and their ability to manage diabetes effectively. Diabetes management also imposes considerable lifestyle demands that are difficult and often frustrating for children to negotiate at a young age. Recent advances in diabetes medications and technologies have improved glycemic control in children with diabetes. Two widely used technologies are the insulin pump and continuous glucose monitoring (CGM) system. These technologies provide patients with more flexibility in their daily life and information about glucose fluctuations. Several studies report improvements in glycemic control in children with type 1 diabetes using the insulin pump or sensor-augmented pump therapy. Importantly, these technologies may impact QOL for children and families with diabetes, although they are rarely used or studied in the treatment of children with type 2 diabetes. Further, emerging closed loop and web- and phone-based technologies have great potential for supporting diabetes self-management and perhaps QOL. A deeper understanding and appreciation of the impact of diabetes technology on children's and parents' QOL is critical for both the medical and psychological care of diabetes. Thus, the purpose of this review is to discuss the impact of new diabetes technologies on QOL in children, adolescents and families with type 1 diabetes.

Association between post-dinner dietary intakes and nocturnal hypoglycemic risk in adult patients with type 1 diabetes.

PubMed

Desjardins, Katherine; Brazeau, Anne-Sophie; Strychar, Irene; Leroux, Catherine; Gingras, Véronique; Rabasa-Lhoret, Rémi

2014-12-01

To describe (i) current bedtime nutritional practices and (ii) the association between post-dinner dietary intake and the occurrence of non-severe nocturnal hypoglycemia (NH) in real-life conditions among adult patients with type 1 diabetes using insulin analogs. One hundred adults (median [interquartile range]: age 46.4 [36.0-55.8] years, HbA1c 7.9 [7.3-8.6] % (63 [56-70] mmol/mol)) using multiple daily injections (n=67) or insulin pump (n=33) wore a blinded continuous glucose monitoring system and completed a food diary for 72-h. NH occurred on 28% of 282 nights analyzed. (i) Patients reported post-dinner dietary intakes on 63% of the evenings. They injected rapid-acting insulin boluses on 64 occasions (23% of 282 evenings). These insulin boluses were mostly injected with (n=37) dietary intakes. (ii) Post-dinner dietary intake was not associated with NH occurrence in univariate analyses. In multivariate analyses, the injection of rapid-acting insulin modulated the association between post-dinner dietary intake and NH: with insulin, post-dinner carbohydrate intake was positively associated with NH (odds ratio (OR): 1.16 [95% confidence interval, CI: 1.04-1.29] per 5g increase, p=0.008); without insulin, post-dinner protein intake was inversely associated with NH occurrence (OR [95% CI]: 0.88 [0.78-1.00] per 2g increase, p=0.048). NH remains frequent in adults with type 1 diabetes. There is a complex relationship between post-dinner dietary intake and NH occurrence, including the significant role of nutrient content and rapid-acting insulin injection that requires further investigation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Insulin therapy in children and adolescents with type 1 diabetes.

PubMed

Malik, Faisal S; Taplin, Craig E

2014-04-01

Treatment of type 1 diabetes mellitus (T1DM) requires lifelong administration of exogenous insulin. The primary goal of treatment of T1DM in children and adolescents is to maintain near-normoglycemia through intensive insulin therapy, avoid acute complications, and prevent long-term microvascular and macrovascular complications, while facilitating as close to a normal life as possible. Effective insulin therapy must, therefore, be provided on the basis of the needs, preferences, and resources of the individual and the family for optimal management of T1DM. To achieve target glycemic control, the best therapeutic option for patients with T1DM is basal-bolus therapy either with multiple daily injections (MDI) or continuous subcutaneous insulin infusion (CSII). Many formulations of insulin are available to help simulate endogenous insulin secretion as closely as possible in an effort to eliminate the symptoms and complications of hyperglycemia, while minimizing the risk of hypoglycemia secondary to therapy. When using MDI, basal insulin requirements are given as an injection of long- or intermediate-acting insulin analogs, while meal-related glucose excursions are controlled with bolus injections of rapid-acting insulin analogs. Alternatively, CSII can be used, which provides a 24-h preselected but adjustable basal rate of rapid-acting insulin, along with patient-activated mealtime bolus doses, eliminating the need for periodic injections. Both MDI treatment and CSII therapy must be supported by comprehensive education that is appropriate for the individual needs of the patient and family before and after initiation. Current therapies still do not match the endogenous insulin profile of pancreatic β-cells, and all still pose risks of suboptimal control, hypoglycemia, and ketosis in children and adolescents. The safety and success of a prescribed insulin regimen is, therefore, dependent on self-monitoring of blood glucose and/or a continuous glucose monitoring system to avoid critical hypoglycemia and glucose variability. Regardless of the mode of insulin therapy, doses should be adapted on the basis of the daily pattern of blood glucose, through regular review and reassessment, and patient factors such as exercise and pubertal status. New therapy options such as sensor-augmented insulin pump therapy, which integrates CSII with a continuous glucose sensor, along with emerging therapies such as the artificial pancreas, will likely continue to improve safe insulin therapy in the near future.

Optimizing the combination insulin bolus split for a high-fat, high-protein meal in children and adolescents using insulin pump therapy.

PubMed

Lopez, P E; Smart, C E; McElduff, P; Foskett, D C; Price, D A; Paterson, M A; King, B R

2017-10-01

To determine the optimum combination bolus split to maintain postprandial glycaemia with a high-fat and high-protein meal in young people with Type 1 diabetes. A total of 19 young people (mean age 12.9 ± 6.7 years) participated in a randomized, repeated-measures trial comparing postprandial glycaemic control across six study conditions after a high-fat and high-protein meal. A standard bolus and five different combination boluses were delivered over 2 h in the following splits: 70/30 = 70% standard /30% extended bolus; 60/40=60% standard/40% extended bolus; 50/50=50% standard/50% extended bolus; 40/60=40% standard/60% extended bolus; and 30/70=30% standard/70% extended bolus. Insulin dose was determined using the participant's optimized insulin:carbohydrate ratio. Continuous glucose monitoring was used to assess glucose excursions for 6 h after the test meal. Standard bolus and combination boluses 70/30 and 60/40 controlled the glucose excursion up to 120 min. From 240 to 300 min after the meal, the glucose area under the curve was significantly lower for combination bolus 30/70 compared with standard bolus (P=0.004). High-fat and high-protein meals require a ≥60% insulin:carbohydrate ratio as a standard bolus to control the initial postprandial rise. Additional insulin at an insulin:carbohydrate ratio of up to 70% is needed in the extended bolus for a high fat and protein meal to prevent delayed hyperglycaemia. © 2017 Diabetes UK.

Treating type 1 diabetes: from strategies for insulin delivery to dual hormonal control

PubMed Central

McCall, A. L.; Farhy, L. S.

2014-01-01

Type 1 diabetes is a disorder where slow destruction of pancreatic β-cells occurs through autoimmune mechanisms. The result is a progressive and ultimately complete lack of endogenous insulin. Due to β-cell lack, secondary abnormalities in glucagon and likely in incretins occur. These multiple hormonal abnormalities cause metabolic instability and extreme glycemic variability, which is the primary phenotype. As the disease progresses patients often develop hypoglycemia unawareness and defects in their counterregulatory defenses. Intensive insulin therapy may thus lead to 3-fold excess of severe hypoglycemia and severely hinder the effective and safe control of hyperglycemia. The main goal of the therapy for type 1 diabetes has long been physiological mimicry of normal insulin secretion based on monitoring which requires considerable effort and understanding of the underlying physiology. Attainment of this goal is challenged by the nature of the disease and our current lack of means to fully repair the abnormal endocrine pancreas interactive functions. As a result, various insulin preparations has been developed to partially compensate for the inability to deliver timely exogenous insulin directly to the portal/intrapancreatic circulation. It remains an ongoing task to identify the ideal routes and regimens of their delivery and potentially that of other hormones to restore the deficient and disordered hormonal environment of the pancreas to achieve a near normal metabolic state. Several recent technological advances help addressing these goals, including the rapid progress in insulin pumps, continuous glucose sensors, and ultimately the artificial pancreas closed-loop technology and the recent start of dual-hormone therapies. PMID:23732369

Time delay compensation for closed-loop insulin delivery systems: a simulation study.

PubMed

Reboldi, G P; Home, P D; Calabrese, G; Fabietti, P G; Brunetti, P; Massi Benedetti, M

1991-06-01

Closed loop insulin therapy certainly represents the best possible approach to insulin replacement. However, present limitations preclude wider application of the so-called artificial pancreas. Therefore, a thorough understanding of these limitations is needed to design better systems for future long-term use. The present simulation study was design: to obtain better information on the impact of the measurement delay of currently available closed-loop devices both during closed-loop insulin delivery and blood glucose clamp studies, and to design and test a time delay compensator based on the method originally described by O.J. Smith. Simulations were performed on a Compaq Deskpro 486/25 personal computer under MS-DOS operating system using Simnon rel. 3.00 software. There was a direct relationship between measurement delay and amount of insulin delivered, i.e., the longer the delay the higher the insulin dose needed to control a rise in blood glucose; the closed-loop response in presence of a time delay was qualitatively impaired both during insulin delivery and blood glucose clamp studies; time delay compensation was effective in reducing the insulin dose and improving controller stability during the early phase of clamp studies. However, the robustness of a Smith's predictor-based controller should be carefully evaluated before implementation in closed-loop systems can be considered.

Efficacy and safety of mini-dose glucagon for treatment of nonsevere hypoglycemia in adults with type 1 diabetes

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to evaluate low-dose glucagon to treat mild hypoglycemia in ambulatory adults with type 1 diabetes (T1D). This was a randomized crossover trial (two 3-week periods) conducted at five U.S. diabetes clinics. Twenty adults with T1D using an insulin pump and continuous gluc...

A miniature, nongassing electroosmotic pump operating at 0.5 V.

PubMed

Shin, Woonsup; Lee, Jong Myung; Nagarale, Rajaram Krishna; Shin, Samuel Jaeho; Heller, Adam

2011-03-02

Electroosmotic pumps are arguably the simplest of all pumps, consisting merely of two flow-through electrodes separated by a porous membrane. Most use platinum electrodes and operate at high voltages, electrolyzing water. Because evolved gas bubbles adhere and block parts of the electrodes and the membrane, steady pumping rates are difficult to sustain. Here we show that when the platinum electrodes are replaced by consumed Ag/Ag(2)O electrodes, the pumps operate well below 1.23 V, the thermodynamic threshold for electrolysis of water at 25 °C, where neither H(2) nor O(2) is produced. The pumping of water is efficient: 13 000 water molecules are pumped per reacted electron and 4.8 mL of water are pumped per joule at a flow rate of 0.13 mL min(-1) V(-1) cm(-2), and a flow rate per unit of power is 290 mL min(-1) W(-1). The water is driven by protons produced in the anode reaction 2Ag(s) + H(2)O → Ag(2)O(s) + 2H(+) + 2e(-), traveling through the porous membrane, consumed by hydroxide ions generated in the cathode reaction Ag(2)O(s) + 2 H(2)O + 2e(-) → 2Ag(s) + 2 OH(-). A pump of 2 mm thickness and 0.3 cm(2) cross-sectional area produces flow of 5-30 μL min(-1) when operating at 0.2-0.8 V and 0.04-0.2 mA. Its flow rate can be either voltage or current controlled. The flow rate suffices for the delivery of drugs, such as a meal-associated boli of insulin.

Prevention of hypoglycemia by using low glucose suspend function in sensor-augmented pump therapy.

PubMed

Danne, Thomas; Kordonouri, Olga; Holder, Martin; Haberland, Holger; Golembowski, Sven; Remus, Kerstin; Bläsig, Sara; Wadien, Tanja; Zierow, Susanne; Hartmann, Reinhard; Thomas, Andreas

2011-11-01

Severe hypoglycemic episodes are a barrier for achieving optimal glycemic control. Sensor-augmented pump (SAP) therapy with insulin in combination with a novel mechanism of automatic insulin shutoff (low glucose suspend [LGS]) can be used to prevent and reduce hypoglycemia. In a prospective study, we investigated the effect of the LGS algorithm on the frequency of hypoglycemia in children and adolescents with type 1 diabetes under real-life conditions. Twenty-one patients with type 1 diabetes (10.8±3.8 years old, duration of diabetes 5.9±3.0 years, pump therapy for 3.7±1.7 years, glycated hemoglobin level 7.8±1.1%) from three pediatric centers used the Paradigm(®) Veo(™) system (Medtronic Minimed, Northridge, CA) during two subseqent time periods: SAP without LGS for 2 weeks and then SAP with LGS enabled for 6 weeks. The primary objective was to assess the frequency of hypoglycemic episodes when using the LGS feature with an insulin delivery shutoff of a maximum of 2 h at a sensor glucose level below 70 mg/dL (3.9 mmol/L). In total, 1,298 LGS alerts occurred (853 shorter than 5 min). Forty-two percent of LGS activations (>5 min) lasted less than 30 min, whereas 24% had a duration of 2 h. The number of hypoglycemic excursions (average/day) was reduced during SAP+LGS (<70 mg/L, 1.27±0.75 vs. 0.95±0.49, P=0.010; ≤40 mg/dL, 0.28±0.18 vs. 0.13±0.14, P=0.005) as was the time spent in hypoglycemia (average minutes/day, 101±68 vs. 58±33, P=0.002) without significant difference in the mean glucose level (145±23 vs. 148±19 mg/dL). No episodes of severe hyperglycemia or diabetic ketoacidosis were observed following LGS activation. The present investigation provides evidence that SAP with LGS reduces the frequency of hypoglycemia without compromising safety.

Increasing the use of 'smart' pump drug libraries by nurses: a continuous quality improvement project.

PubMed

Harding, Andrew D

2012-01-01

The use of infusion pumps that incorporate "smart" technology (smart pumps) can reduce the risks associated with receiving IV therapies. Smart pump technology incorporates safeguards such as a list of high-alert medications, soft and hard dosage limits, and a drug library that can be tailored to specific patient care areas. Its use can help to improve patient safety and to avoid potentially catastrophic harm associated with medication errors. But when one independent community hospital in Massachusetts switched from older mechanical pumps to smart pumps, it neglected to assign an "owner" to oversee the implementation process. One result was that nurses were using the smart pump library for only 37% of all infusions.To increase pump library usage percentage-thereby reducing the risks associated with infusion and improving patient safety-the hospital undertook a continuous quality improvement project over a four-month period in 2009. With the involvement of direct care nurses, and using quantitative data available from the smart pump software, the nursing quality and pharmacy quality teams identified ways to improve pump and pump library use. A secondary goal was to calculate the hospital's return on investment for the purchase of the smart pumps. Several interventions were developed and, on the first of each month, implemented. By the end of the project, pump library usage had nearly doubled; and the hospital had completely recouped its initial investment.

Off-pump versus on-pump coronary artery bypass surgery in patients with actively treated diabetes and multivessel coronary disease.

PubMed

Benedetto, Umberto; Caputo, Massimo; Vohra, Hunaid; Davies, Alan; Hillier, James; Bryan, Alan; Angelini, Gianni D

2016-11-01

We conducted a single-center analysis on short-term outcomes and long-term survival in actively treated diabetic patients undergoing off-pump coronary artery bypass versus on-pump coronary artery bypass surgery. The final population consisted of 2450 patients with actively treated diabetes (mean age, 66 ± 9 years; female/male 545/1905, 22%). Of those, 1493 subjects were orally treated and 1011 subjects were taking insulin. Off-pump coronary artery bypass and on-pump coronary artery bypass were performed in 1253 and 1197 patients, respectively. Propensity score matching was used to compare the 2 matched groups. When compared with on-pump coronary artery bypass, off-pump coronary artery bypass was associated with a significant risk reduction for postoperative cerebrovascular accident (odds ratio, 0.49; 95% confidence interval [CI], 0.25-0.99; P = .04), need for postoperative intra-aortic balloon pump (odds ratio, 0.48; 95% CI, 0.30-0.77; P = .002), and reexploration for bleeding (odds ratio, 0.55; 95% CI, 0.33-0.94; P = .02). Off-pump coronary artery bypass did not significantly affect early (hazard ratio [HR], 1.32; 95% CI, 0.73-2.40; P = .36) and late (HR, 1.08; 95% CI, 0.92-1.28; P = .32) mortality. However, off-pump coronary artery bypass with incomplete revascularization was associated with reduced survival when compared with off-pump coronary artery bypass with complete revascularization (HR, 1.82; 95% CI, 1.34-2.46; P = .0002) and on-pump coronary artery bypass with complete revascularization (HR, 1.83; 95% CI, 1.36-2.47; P < .0001). Off-pump coronary artery bypass is a safe and feasible option for diabetic patients with multivessel disease, reduces the incidence of early complications including postoperative cerebrovascular events, and provides excellent long-term survival similar to on-pump coronary artery bypass surgery in case of complete revascularization. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Predictors of Hypoglycemia in the ASPIRE In-Home Study and Effects of Automatic Suspension of Insulin Delivery.

PubMed

Weiss, Ram; Garg, Satish K; Bergenstal, Richard M; Klonoff, David C; Bode, Bruce W; Bailey, Timothy S; Thrasher, James; Schwartz, Frank; Welsh, John B; Kaufman, Francine R

2015-05-18

Hypoglycemia varies between patients with type 1 diabetes and is the main obstacle to therapy intensification. We investigated known and potential risk factors for hypoglycemia in subjects with type 1 diabetes. In the ASPIRE In-Home study (NCT01497938), a randomized trial of the threshold suspend (TS) feature of sensor-augmented insulin pump (SAP) therapy, subjects' propensity to nocturnal hypoglycemia (NH) was established in a 2-week run-in phase and assessed in a 3-month study phase via continuous glucose monitoring. Categorical variables were tested for association with NH rates in both phases. Elevated rates of NH were significantly associated with baseline A1C ≤7%, with bolus insulin deliveries unassisted by the bolus estimation calculator, and with assignment to the control group during the study phase. Routine use of the TS feature and the bolus estimation calculator are strategies that may reduce the risk of NH. © 2015 Diabetes Technology Society.

Packaged peristaltic micropump for controlled drug delivery application

NASA Astrophysics Data System (ADS)

Vinayakumar, K. B.; Nadiger, Girish; R. Shetty, Vikas; Dinesh, N. S.; Nayak, M. M.; Rajanna, K.

2017-01-01

Micropump technology has evolved significantly in the last two decades and is finding a variety of applications ranging from μTAS (micro Total Analysis System) to drug delivery. However, the application area of the micropump is limited owing to: simple pumping mechanism, ease of handling, controlled (microliter to milliliter) delivery, continuous delivery, and accuracy in flow rate. Here, the author presents the design, development, characterization, and precision flow controlling of a DC-motor driven peristaltic pump for controlled drug delivery application. All the micropump components were fabricated using the conventional fabrication technique. The volume flow variation of the pump has been characterized for different viscous fluids. The change in volume flow due to change in back pressure has been presented in detail. The fail-safe mode operation of the pump has been tested and leak rate was measured (˜0.14% leak for an inlet pressure of 140 kPa) for different inlet pressures. The precision volume flow of the pump has been achieved by measuring the pinch cam position and load current. The accuracy in the volume flow has been measured after 300 rotations. Finally, the complete system has been integrated with the necessary electronics and an android application has been developed for the self-administration of bolus and basal delivery of insulin.

A Method of Porcine Pancreatic Islet Isolation for Microencapsulation.

PubMed

Kendall, William F; Opara, Emmanuel C

2017-01-01

Since the discovery of insulin by Banting and Best in 1921, the prognosis and treatment options for individuals with diabetes have improved. The development of various insulin types, various oral agents, and insulin pumps have improved the available medical options for individuals afflicted with diabetes. The current need for frequent blood glucose monitoring imposed by multiple daily insulin injections, result in significant life-style challenges for in individuals afflicted with Type 1 diabetes (T1D). In contrast the use of surgical interventions, such as whole organ pancreas transplantation (PT) requires less-intensive glucose monitoring while the organ is viable. Also, isolated human pancreatic islet transplantation (IT) holds similar promise as PT; however, the limited availability of human pancreata exacerbated by, the need for multiple pancreata per individual IT recipient, and issues with prolonged viability, still hamper widespread successful, and routine use of IT. The use of porcine pancreata holds promise as a viable alternative to human pancreas to significantly increase the volume of islets available to meet the needs of millions of patients afflicted with T1D. This chapter outlines our protocol utilized to reliably isolate and microencapsulate porcine islets.

When Intensive Insulin Therapy (MDI) Fails in Patients With Type 2 Diabetes: Switching to GLP-1 Receptor Agonist Versus Insulin Pump.

PubMed

Cohen, Ohad; Filetti, Sebastiano; Castañeda, Javier; Maranghi, Marianna; Glandt, Mariela

2016-08-01

Treatment with insulin, alone or with oral or injectable hypoglycemic agents, is becoming increasingly common in patients with type 2 diabetes. However, approximately 40% of patients fail to reach their glycemic targets with the initially prescribed regimen and require intensification of insulin therapy, which increases the risks of weight gain and hypoglycemia. Many of these patients eventually reach a state in which further increases in the insulin dosage fail to improve glycemic control while increasing the risks of weight gain and hypoglycemia. The recently completed OpT2mise clinical trial showed that continuous subcutaneous insulin infusion (CSII) is more effective in reducing glycated hemoglobin (HbA1c) than intensification of multiple daily injection (MDI) insulin therapy in patients with type 2 diabetes who do not respond to intensive insulin therapy. CSII therapy may also be useful in patients who do not reach glycemic targets despite multidrug therapy with basal-bolus insulin and other agents, including glucagon-like peptide (GLP)-1 receptor agonists; current guidelines offer no recommendations for the treatment of such patients. Importantly, insulin and GLP-1 receptor agonists have complementary effects on glycemia and, hence, can be used either sequentially or in combination in the initial management of diabetes. Patients who have not previously failed GLP-1 receptor agonist therapy may show reduction in weight and insulin dose, in addition to moderate improvement in HbA1c, when GLP-1 receptor agonist therapy is added to MDI regimens. In subjects with long-standing type 2 diabetes who do not respond to intensive insulin therapies, switching from MDI to CSII and/or the addition of GLP-1 receptor agonists to MDI have the potential to improve glycemic control without increasing the risk of adverse events. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

High efficiency and good beam quality of electro-optic, cavity-dumped and double-end pumped Nd:YLF laser

NASA Astrophysics Data System (ADS)

Tang, X. X.; Fan, Z. W.; Qiu, J. S.; Lian, F. Q.; Zhang, X. L.

2012-06-01

In this paper, we describe a Nd:YLF laser based on high-speed RTP electro-optical cavity dumping technique. Two home-made 150 W fiber pump modules are used from both sides to pump Nd:YLF crystal. Coupling systems are the key elements in end-pumped solid-state lasers, the aberrations of which greatly affect the efficiency of the lasers. In order to get high efficient and good quality laser output, the optical software ZEMAX is used to design a four-piece coupling system. When the pumped energy is 32 mJ at the repetition rate of 1 Hz, the output energy is 6.5 mJ with 2.5 ns pulse width. When the pumped energy is 13.1 W at the repetition rate of 200 Hz, the output energy is 2.2 W with small M 2 factor where M {/x 2} is 1.04, and M {/y 2} is 1.05, and the light-light conversion efficiency is up to 16.8%.

Effect of artificial pancreas systems on glycaemic control in patients with type 1 diabetes: a systematic review and meta-analysis of outpatient randomised controlled trials.

PubMed

Weisman, Alanna; Bai, Johnny-Wei; Cardinez, Marina; Kramer, Caroline K; Perkins, Bruce A

2017-07-01

Closed-loop artificial pancreas systems have been in development for several years, including assessment in numerous varied outpatient clinical trials. We aimed to summarise the efficacy and safety of artificial pancreas systems in outpatient settings and explore the clinical and technical factors that can affect their performance. We did a systematic review and meta-analysis of randomised controlled trials comparing artificial pancreas systems (insulin only or insulin plus glucagon) with conventional pump therapy (continuous subcutaneous insulin infusion [CSII] with blinded continuous glucose monitoring [CGM] or unblinded sensor-augmented pump [SAP] therapy) in adults and children with type 1 diabetes. We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials for studies published from 1946, to Jan 1, 2017. We excluded studies not published in English, those involving pregnant women or participants who were in hospital, and those testing adjunct medications other than glucagon. The primary outcome was the mean difference in percentage of time blood glucose concentration remained in target range (3·9-10 mmol/L or 3·9-8 mmol/L, depending on the study), assessed by random-effects meta-analysis. This study is registered with PROSPERO, number 2015:CRD42015026854. We identified 984 reports; after exclusions, 27 comparisons from 24 studies (23 crossover and one parallel design) including a total of 585 participants (219 in adult studies, 265 in paediatric studies, and 101 in combined studies) were eligible for analysis. Five comparisons assessed dual-hormone (insulin and glucagon), two comparisons assessed both dual-hormone and single-hormone (insulin only), and 20 comparisons assessed single-hormone artificial pancreas systems. Time in target was 12·59% higher with artificial pancreas systems (95% CI 9·02-16·16; p<0·0001), from a weighted mean of 58·21% for conventional pump therapy (I 2 =84%). Dual-hormone artificial pancreas systems were associated with a greater improvement in time in target range compared with single-hormone systems (19·52% [95% CI 15·12-23·91] vs 11·06% [6·94 to 15·18]; p=0·006), although six of seven comparisons compared dual-hormone systems to CSII with blinded CGM, whereas 21 of 22 single-hormone comparisons had SAP as the comparator. Single-hormone studies had higher heterogeneity than dual-hormone studies (I 2 79% vs 66%). Bias assessment characteristics were incompletely reported in 12 of 24 studies, no studies masked participants to the intervention assignment, and masking of outcome assessment was not done in 12 studies and was unclear in 12 studies. Artificial pancreas systems uniformly improved glucose control in outpatient settings, despite heterogeneous clinical and technical factors. None. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of 12 weeks' treatment with a proton pump inhibitor on insulin secretion, glucose metabolism and markers of cardiovascular risk in patients with type 2 diabetes: a randomised double-blind prospective placebo-controlled study.

PubMed

Hove, K D; Brøns, C; Færch, K; Lund, S S; Petersen, J S; Karlsen, A E; Rossing, P; Rehfeld, J F; Vaag, A

2013-01-01

Recent studies suggest that proton pump inhibitor treatment may increase insulin secretion and improve glucose metabolism in type 2 diabetes. In a randomised double-blind prospective placebo-controlled 2 × 2 factorial study, we examined the effect of esomeprazole on insulin secretion, HbA(1c) and cardiovascular risk factors in type 2 diabetes. Forty-one patients with type 2 diabetes using dietary control or oral glucose-lowering treatment were randomised to receive add-on esomeprazole 40 mg (n = 20) or placebo (n = 21) for 12 weeks. Randomisation was carried out prior to inclusion on the basis of a computer-generated random-number list. The allocation sequence was concealed in sealed envelopes from the researcher enrolling and assessing participants. The study was undertaken at Steno Diabetes Center, Gentofte, Denmark. The primary outcome was change in AUC for insulin levels during a meal test. Secondary outcomes were the levels of HbA(1c) and biochemical markers of cardiovascular risk, including lipids, coagulation factors, inflammation markers, markers of endothelial function and 24 h ambulatory BP measurements. Forty-one participants were analysed. In the esomeprazole-treated group the AUC for insulin did not change (before vs after treatment: 28,049 ± 17,659 vs 27,270 ± 32,004 pmol/l × min (p = 0.838). In the placebo group AUC for insulin decreased from 27,392 ± 14,348 pmol/l × min to 22,938 ± 11,936 pmol/l × min (p = 0.002). Esomeprazole treatment (n = 20) caused a ninefold increase in the AUC for gastrin. HbA(1c) increased from 7.0 ± 0.6% (53 ± 5 mmol/mol) to 7.3 ± 0.8% (56 ± 6 mmol/mol) in the esomeprazole-treated group and from 7.0 ± 0.6% (53 ± 5 mmol/mol) to 7.4 ± 0.8% (57 ± 6 mmol/mol) in the placebo group (n = 21) (p for difference in change >0.05). Except for BP, there were no differences between the groups in the markers of cardiovascular risk (p > 0.05). Monitoring of 24 h ambulatory BP showed a significant decrease in daytime systolic BP, daytime diastolic BP and 24 h diastolic BP in the placebo group (p < 0.05). No change in BP was seen in the patients treated with esomeprazole. Treatment with esomeprazole over 12 weeks did not improve insulin secretion, glycaemic control or cardiovascular disease biomarkers in patients with type 2 diabetes.

Screw-actuated displacement micropumps for thermoplastic microfluidics.

PubMed

Han, J Y; Rahmanian, O D; Kendall, E L; Fleming, N; DeVoe, D L

2016-10-05

The fabrication of on-chip displacement pumps integrated into thermoplastic chips is explored as a simple and low cost method for achieving precise and programmable flow control for disposable microfluidic systems. The displacement pumps consist of stainless steel screws inserted into threaded ports machined into a thermoplastic substrate which also serve as on-chip reagent storage reservoirs. Three different methods for pump sealing are investigated to enable high pressure flows without leakage, and software-defined control of multiple pumps is demonstrated in a self-contained platform using a compact and self-contained microcontroller for operation. Using this system, flow rates ranging from 0.5-40 μl min -1 are demonstrated. The pumps are combined with on-chip burst valves to fully seal multiple reagents into fabricated chips while providing on-demand fluid distribution in a downstream microfluidic network, and demonstrated for the generation of size-tunable water-in-oil emulsions.

Modeling and Performance Improvement of the Constant Power Regulator Systems in Variable Displacement Axial Piston Pump

PubMed Central

Park, Sung Hwan; Lee, Ji Min; Kim, Jong Shik

2013-01-01

An irregular performance of a mechanical-type constant power regulator is considered. In order to find the cause of an irregular discharge flow at the cut-off pressure area, modeling and numerical simulations are performed to observe dynamic behavior of internal parts of the constant power regulator system for a swashplate-type axial piston pump. The commercial numerical simulation software AMESim is applied to model the mechanical-type regulator with hydraulic pump and simulate the performance of it. The validity of the simulation model of the constant power regulator system is verified by comparing simulation results with experiments. In order to find the cause of the irregular performance of the mechanical-type constant power regulator system, the behavior of main components such as the spool, sleeve, and counterbalance piston is investigated using computer simulation. The shape modification of the counterbalance piston is proposed to improve the undesirable performance of the mechanical-type constant power regulator. The performance improvement is verified by computer simulation using AMESim software. PMID:24282389

Hypoglycaemia incidence and recovery during home use of hybrid closed-loop insulin delivery in adults with type 1 diabetes.

PubMed

Ruan, Yue; Bally, Lia; Thabit, Hood; Leelarathna, Lalantha; Hartnell, Sara; Tauschmann, Martin; Wilinska, Malgorzata E; Evans, Mark L; Mader, Julia K; Kojzar, Harald; Dellweg, Sibylle; Benesch, Carsten; Arnolds, Sabine; Pieber, Thomas R; Hovorka, Roman

2018-03-25

Glucose excursion was assessed prior to and post hypoglycaemia to increase understanding of hypoglycaemia incidence and recovery during hybrid closed-loop insulin delivery. We retrospectively analysed data from 60 adults with type 1 diabetes who received, in a crossover randomized design, day-and-night hybrid closed-loop insulin delivery and insulin pump therapy, the latter with or without real-time continuous glucose monitoring. Over 4-week study periods, we identified hypoglycaemic episodes, defined as sensor glucose <3.0 mmol/L, and analysed sensor glucose relative to the onset of hypoglycaemia. We identified 377 hypoglycaemic episodes during hybrid closed-loop intervention vs 662 during control intervention (P < .001), with a predominant reduction of nocturnal hypoglycaemia. The slope of sensor glucose prior to hypoglycaemia was steeper during closed-loop intervention than during control intervention (P < .01), while insulin delivery was reduced (P < .01). During both day and night, participants recovered from hypoglycaemia faster when treated by closed-loop intervention. At 120 minutes post hypoglycaemia, sensor glucose levels were higher during closed-loop intervention compared to the control period (P < .05). In conclusion, closed-loop intervention reduces the risk of hypoglycaemia, particularly overnight, with swift recovery from hypoglycaemia leading to higher 2-hour post-hypoglycaemia glucose levels. © 2018 John Wiley & Sons Ltd.

Palmitate-Induced Vacuolar-Type H+-ATPase Inhibition Feeds Forward Into Insulin Resistance and Contractile Dysfunction.

PubMed

Liu, Yilin; Steinbusch, Laura K M; Nabben, Miranda; Kapsokalyvas, Dimitris; van Zandvoort, Marc; Schönleitner, Patrick; Antoons, Gudrun; Simons, Peter J; Coumans, Will A; Geomini, Amber; Chanda, Dipanjan; Glatz, Jan F C; Neumann, Dietbert; Luiken, Joost J F P

2017-06-01

Dietary fat overconsumption leads to myocardial lipid accumulation through mechanisms that are incompletely resolved. Previously, we identified increased translocation of the fatty acid transporter CD36 from its endosomal storage compartment to the sarcolemma as the primary mechanism of excessive myocellular lipid import. Here, we show that increased CD36 translocation is caused by alkalinization of endosomes resulting from inhibition of proton pumping activity of vacuolar-type H + -ATPase (v-ATPase). Endosomal alkalinization was observed in hearts from rats fed a lard-based high-fat diet and in rodent and human cardiomyocytes upon palmitate overexposure, and appeared as an early lipid-induced event preceding the onset of insulin resistance. Either genetic or pharmacological inhibition of v-ATPase in cardiomyocytes exposed to low palmitate concentrations reduced insulin sensitivity and cardiomyocyte contractility, which was rescued by CD36 silencing. The mechanism of palmitate-induced v-ATPase inhibition involved its dissociation into two parts: the cytosolic V 1 and the integral membrane V 0 subcomplex. Interestingly, oleate also inhibits v-ATPase function, yielding triacylglycerol accumulation but not insulin resistance. In conclusion, lipid oversupply increases CD36-mediated lipid uptake that directly impairs v-ATPase function. This feeds forward to enhanced CD36 translocation and further increased lipid uptake. In the case of palmitate, its accelerated uptake ultimately precipitates into cardiac insulin resistance and contractile dysfunction. © 2017 by the American Diabetes Association.

Product-based Safety Certification for Medical Devices Embedded Software.

PubMed

Neto, José Augusto; Figueiredo Damásio, Jemerson; Monthaler, Paul; Morais, Misael

2015-01-01

Worldwide medical device embedded software certification practices are currently focused on manufacturing best practices. In Brazil, the national regulatory agency does not hold a local certification process for software-intensive medical devices and admits international certification (e.g. FDA and CE) from local and international industry to operate in the Brazilian health care market. We present here a product-based certification process as a candidate process to support the Brazilian regulatory agency ANVISA in medical device software regulation. Center of Strategic Technology for Healthcare (NUTES) medical device embedded software certification is based on a solid safety quality model and has been tested with reasonable success against the Class I risk device Generic Infusion Pump (GIP).

Optimized Biasing of Pump Laser Diodes in a Highly Reliable Metrology Source for Long-Duration Space Missions

NASA Technical Reports Server (NTRS)

Poberezhskiy, Ilya; Chang, Daniel; Erlig, Hernan

2011-01-01

Non Planar Ring Oscillator (NPRO) lasers are highly attractive for metrology applications. NPRO reliability for prolonged space missions is limited by reliability of 808 nm pump diodes. Combined laser farm aging parameter allows comparing different bias approaches. Monte-Carlo software developed to calculate the reliability of laser pump architecture, perform parameter sensitivity studies To meet stringent Space Interferometry Mission (SIM) Lite lifetime reliability / output power requirements, we developed a single-mode Laser Pump Module architecture that: (1) provides 2 W of power at 808 nm with >99.7% reliability for 5.5 years (2) consists of 37 de-rated diode lasers operating at -5C, with outputs combined in a very low loss 37x1 all-fiber coupler

Prevalence and predictors of severe hypoglycemia in Danish children and adolescents with diabetes.

PubMed

Johansen, A; Kanijo, B; Fredheim, S; Olsen, B; Hertz, B; Lauridsen, M H; Andersen, M L M; Mortensen, H B; Svensson, J

2015-08-01

To investigate the prevalence of severe hypoglycemia in Danish children and adolescents with type 1 diabetes and to pinpoint predictors of this acute complication in children on modern treatment modalities. The study is based on data from DanDiabKids, a national diabetes register for children and adolescents. The register contains data on patients with type 1 diabetes with an ascertainment rate of 99%. Data from 3320 patients aged 0-18 yr was included in the study period from 1998 to 2009 and analyzed using a negative binomial model. One thousand nine hundred and ninety-nine episodes of severe hypoglycemia in 867 patients were registered conferring an overall incidence of severe hypoglycemia of 15.1 [95% confident interval (CI): 13.8; 16.4] per 100 patient years. This remained unchanged during the study period. Duration of diabetes, age and treatment in centers managing less than 100 patients significantly increased the risk of severe hypoglycemia (p < 0.001). Patients on insulin pump therapy had a 42% reduced risk of severe hypoglycemia compared with pen treated patients (p = 0.01). Patients treated with five or more daily insulin injections had a 31% (95% CI: 17; 49) reduced risk of severe hypoglycemia compared to patients on fewer daily injections (p = 0.015). Despite improvements in metabolic control over a decade the prevalence of severe hypoglycemic events remained unchanged. More intensive treatments such as insulin pump therapy and multiple daily injections on a national level seems to be a protective factor for developing severe hypoglycemia up to 2009. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Destabilization of Human Insulin Fibrils by Peptides of Fruit Bromelain Derived From Ananas comosus (Pineapple).

PubMed

Das, Sromona; Bhattacharyya, Debasish

2017-12-01

Deposition of insulin aggregates in human body leads to dysfunctioning of several organs. Effectiveness of fruit bromelain from pineapple in prevention of insulin aggregate was investigated. Proteolyses of bromelain was done as par human digestive system and the pool of small peptides was separated from larger peptides and proteins. Under conditions of growth of insulin aggregates from its monomers, this pool of peptides restricted the reaction upto formation of oligomers of limited size. These peptides also destabilized preformed insulin aggregates to oligomers. These processes were followed fluorimetrically using Thioflavin T and 1-ANS, size-exclusion HPLC, dynamic light scattering, atomic force microscopy, and transmission electron microscopy. Sequences of insulin (A and B chains) and bromelain were aligned using Clustal W software to predict most probable sites of interactions. Synthetic tripeptides corresponding to the hydrophobic interactive sites of bromelain showed disaggregation of insulin suggesting specificity of interactions. The peptides GG and AAA serving as negative controls showed no potency in destabilization of aggregates. Disaggregation potency of the peptides was also observed when insulin was deposited on HepG2 liver cells where no formation of toxic oligomers occurred. Amyloidogenic des-octapeptide (B23-B30 of insulin) incapable of cell signaling showed cytotoxicity similar to insulin. This toxicity could be neutralized by bromelain derived peptides. FT-IR and far-UV circular dichroism analysis indicated that disaggregated insulin had structure distinctly different from that of its hexameric (native) or monomeric states. Based on the stoichiometry of interaction and irreversibility of disaggregation, the mechanism/s of the peptides and insulin interactions has been proposed. J. Cell. Biochem. 118: 4881-4896, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Programmable Infusion Pumps in ICUs: An Analysis of Corresponding Adverse Drug Events

PubMed Central

Bower, Anthony G.; Paddock, Susan M.; Hilborne, Lee H.; Wallace, Peggy; Rothschild, Jeffrey M.; Griffin, Anne; Fairbanks, Rollin J.; Carlson, Beverly; Panzer, Robert J.; Brook, Robert H.

2007-01-01

Background Patients in intensive care units (ICUs) frequently experience adverse drug events involving intravenous medications (IV-ADEs), which are often preventable. Objectives To determine how frequently preventable IV-ADEs in ICUs match the safety features of a programmable infusion pump with safety software (“smart pump”) and to suggest potential improvements in smart-pump design. Design Using retrospective medical-record review, we examined preventable IV-ADEs in ICUs before and after 2 hospitals replaced conventional pumps with smart pumps. The smart pumps alerted users when programmed to deliver duplicate infusions or continuous-infusion doses outside hospital-defined ranges. Participants 4,604 critically ill adults at 1 academic and 1 nonacademic hospital. Measurements Preventable IV-ADEs matching smart-pump features and errors involved in preventable IV-ADEs. Results Of 100 preventable IV-ADEs identified, 4 involved errors matching smart-pump features. Two occurred before and 2 after smart-pump implementation. Overall, 29% of preventable IV-ADEs involved overdoses; 37%, failures to monitor for potential problems; and 45%, failures to intervene when problems appeared. Error descriptions suggested that expanding smart pumps’ capabilities might enable them to prevent more IV-ADEs. Conclusion The smart pumps we evaluated are unlikely to reduce preventable IV-ADEs in ICUs because they address only 4% of them. Expanding smart-pump capabilities might prevent more IV-ADEs. PMID:18095043

Risk of adverse effects of intensified treatment in insulin-dependent diabetes mellitus: a meta-analysis.

PubMed

Egger, M; Davey Smith, G; Stettler, C; Diem, P

1997-11-01

While the benefits of intensified insulin treatment in insulin-dependent (Type 1) diabetes mellitus (IDDM) are well recognized, the risks have not been comprehensively characterized. We examined the risk of severe hypoglycaemia, ketoacidosis, and death in a meta-analysis of randomized controlled trials. The MEDLINE database, reference lists, and specialist journals were searched electronically or by hand to identify relevant studies with at least 6 months of follow-up and the monitoring of glycaemia by glycosylated haemoglobin measurements. Logistic regression was used for calculation of combined odds ratios and 95% confidence intervals (95% CI). The influence of covariates was examined by including covariate-by-treatment interaction terms. Methodological study quality was assessed and sensitivity analyses were performed. Fourteen trials were identified. These contributed 16 comparisons with 1028 patients allocated to intensified and 1039 allocated to conventional treatment. A total of 846 patients suffered at least one episode of severe hypoglycaemia, 175 patients experienced ketoacidosis and 26 patients died. The combined odds ratio (95% CI) for hypoglycaemia was 2.99 (2.45-3.64), for ketoacidosis 1.74 (1.27-2.38) and for death from all causes 1.40 (0.65-3.01). The risk of severe hypoglycaemia was determined by the degree of normalization of glycaemia achieved (p=0.005 for interaction term), with the results from the Diabetes Control and Complications Trial (DCCT) in line with the other trials. Ketoacidosis risk depended on the type of intensified treatment used. Odds ratios (95% CI) were 7.20 (2.95-17.58) for exclusive use of pumps, 1.13 (0.15-8.35) for multiple daily injections and 1.28 (0.90-1.83) for trials offering a choice between the two (p = 0.004 for interaction). Mortality was significantly (p = 0.007) increased for causes potentially associated with acute complications (7 vs 0 deaths, 5 deaths attributed to ketoacidosis, and 2 sudden deaths), and non-significantly (p = 0.16) decreased for macrovascular causes (3 vs 8 deaths). We conclude that there is a substantial risk of severe adverse effects associated with intensified insulin treatment. Mortality from acute metabolic causes is increased; however, this is largely counterbalanced by a reduction in cardiovascular mortality. The excess of severe hypoglycemia in the DCCT is not exceptional. Multiple daily injection schemes may be safer than treatment with insulin pumps.

Central infusion of leptin improves insulin resistance and suppresses beta-cell function, but not beta-cell mass, primarily through the sympathetic nervous system in a type 2 diabetic rat model.

PubMed

Park, Sunmin; Ahn, Il Sung; Kim, Da Sol

2010-06-05

We investigated whether hypothalamic leptin alters beta-cell function and mass directly via the sympathetic nervous system (SNS) or indirectly as the result of altered insulin resistant states. The 90% pancreatectomized male Sprague Dawley rats had sympathectomy into the pancreas by applying phenol into the descending aorta (SNSX) or its sham operation (Sham). Each group was divided into two sections, receiving either leptin at 300ng/kgbw/h or artificial cerebrospinal fluid (aCSF) via intracerebroventricular (ICV) infusion for 3h as a short-term study. After finishing the infusion study, ICV leptin (3mug/kg bw/day) or ICV aCSF (control) was infused in rats fed 30 energy % fat diets by osmotic pump for 4weeks. At the end of the long-term study, glucose-stimulated insulin secretion and islet morphometry were analyzed. Acute ICV leptin administration in Sham rats, but not in SNSX rats, suppressed the first- and second-phase insulin secretion at hyperglycemic clamp by about 48% compared to the control. Regardless of SNSX, the 4-week administration of ICV leptin improved glucose tolerance during oral glucose tolerance tests and insulin sensitivity at hyperglycemic clamp, compared to the control, while it suppressed second-phase insulin secretion in Sham rats but not in SNSX rats. However, the pancreatic beta-cell area and mass were not affected by leptin and SNSX, though ICV leptin decreased individual beta-cell size and concomitantly increased beta-cell apoptosis in Sham rats. Leptin directly decreases insulin secretion capacity mainly through the activation of SNS without modulating pancreatic beta-cell mass.

A Role for Glutamate Transporters in the Regulation of Insulin Secretion

PubMed Central

Gammelsaeter, Runhild; Coppola, Thierry; Marcaggi, Païkan; Storm-Mathisen, Jon; Chaudhry, Farrukh A.; Attwell, David; Regazzi, Romano; Gundersen, Vidar

2011-01-01

In the brain, glutamate is an extracellular transmitter that mediates cell-to-cell communication. Prior to synaptic release it is pumped into vesicles by vesicular glutamate transporters (VGLUTs). To inactivate glutamate receptor responses after release, glutamate is taken up into glial cells or neurons by excitatory amino acid transporters (EAATs). In the pancreatic islets of Langerhans, glutamate is proposed to act as an intracellular messenger, regulating insulin secretion from β-cells, but the mechanisms involved are unknown. By immunogold cytochemistry we show that insulin containing secretory granules express VGLUT3. Despite the fact that they have a VGLUT, the levels of glutamate in these granules are low, indicating the presence of a protein that can transport glutamate out of the granules. Surprisingly, in β-cells the glutamate transporter EAAT2 is located, not in the plasma membrane as it is in brain cells, but exclusively in insulin-containing secretory granules, together with VGLUT3. In EAAT2 knock out mice, the content of glutamate in secretory granules is higher than in wild type mice. These data imply a glutamate cycle in which glutamate is carried into the granules by VGLUT3 and carried out by EAAT2. Perturbing this cycle by knocking down EAAT2 expression with a small interfering RNA, or by over-expressing EAAT2 or a VGLUT in insulin granules, significantly reduced the rate of granule exocytosis. Simulations of granule energetics suggest that VGLUT3 and EAAT2 may regulate the pH and membrane potential of the granules and thereby regulate insulin secretion. These data suggest that insulin secretion from β-cells is modulated by the flux of glutamate through the secretory granules. PMID:21853059

Who is downloading the free AIDA v4.3a interactive educational diabetes computer software? A 1-year survey of 3864 downloads.

PubMed

Lehmann, Eldon D

2003-01-01

AIDA is a free diabetes computer program that permits the interactive simulation of plasma insulin and blood glucose profiles for educational, demonstration, self-learning, and research purposes. To date over 70000 copies of the software have been downloaded from the AIDA Website, www.2aida.org. This column documents a survey of downloaders of the latest release of the program (AIDA v4.3a). The Internet-based survey methodology was confirmed to be robust and reliable. Over a 1-year period (from March 2001 to February 2002) in total 3864 responses were received. During the corresponding period some 8578 actual downloads of the software were independently logged via the same route at the AIDA Website, giving a response rate for this survey of 45%. Responses were received from participants in 66 countries - over half of these (n = 2,137; 55.3%) were from the United States and the United Kingdom. There were 2318 responses (60.0%) received from patients with diabetes and 443 (11.5%) from relatives of patients, with fewer responses from doctors, students, diabetes educators, nurses, pharmacists, and other end users. This study highlights considerable interest amongst patients and their relatives to learn more about balancing insulin and diet in diabetes, as well as possibly to get more involved in self-management of insulin dosages. More computer applications that can cater for this interest in diabetes patient self-care need to be developed and made available. The Internet provides an ideal medium for the distribution of such educational tools.

Assessing performance of closed-loop insulin delivery systems by continuous glucose monitoring: drawbacks and way forward.

PubMed

Hovorka, Roman; Nodale, Marianna; Haidar, Ahmad; Wilinska, Malgorzata E

2013-01-01

We investigated whether continuous glucose monitoring (CGM) levels can accurately assess glycemic control while directing closed-loop insulin delivery. Data were analyzed retrospectively from 33 subjects with type 1 diabetes who underwent closed-loop and conventional pump therapy on two separate nights. Glycemic control was evaluated by reference plasma glucose and contrasted against three methods based on Navigator (Abbott Diabetes Care, Alameda, CA) CGM levels. Glucose mean and variability were estimated by unmodified CGM levels with acceptable clinical accuracy. Time when glucose was in target range was overestimated by CGM during closed-loop nights (CGM vs. plasma glucose median [interquartile range], 86% [65-97%] vs. 75% [59-91%]; P=0.04) but not during conventional pump therapy (57% [32-72%] vs. 51% [29-68%]; P=0.82) providing comparable treatment effect (mean [SD], 28% [29%] vs. 23% [21%]; P=0.11). Using the CGM measurement error of 15% derived from plasma glucose-CGM pairs (n=4,254), stochastic interpretation of CGM gave unbiased estimate of time in target during both closed-loop (79% [62-86%] vs. 75% [59-91%]; P=0.24) and conventional pump therapy (54% [33-66%] vs. 51% [29-68%]; P=0.44). Treatment effect (23% [24%] vs. 23% [21%]; P=0.96) and time below target were accurately estimated by stochastic CGM. Recalibrating CGM using reference plasma glucose values taken at the start and end of overnight closed-loop was not superior to stochastic CGM. CGM is acceptable to estimate glucose mean and variability, but without adjustment it may overestimate benefit of closed-loop. Stochastic CGM provided unbiased estimate of time when glucose is in target and below target and may be acceptable for assessment of closed-loop in the outpatient setting.

Numerical and clinical precision of continuous glucose monitoring in Colombian patients treated with insulin infusion pump with automated suspension in hypoglycemia.

PubMed

Gómez, Ana M; Marín Sánchez, Alejandro; Muñoz, Oscar M; Colón Peña, Christian Alejandro

2015-12-01

Insulin pump therapy associated with continuous glucose monitoring has shown a positive clinical impact on diabetes control and reduction of hypoglycemia episodes. There are descriptions of the performance of this device in other populations, but its precision and accuracy in Colombia and Latin America are unknown, especially in the routine outpatient setting. Data from 33 type 1 and type 2 diabetes patients with sensor-augmented pump therapy with threshold suspend automation, MiniMed Paradigm® Veo™ (Medtronic, Northridge, California), managed at Hospital Universitario San Ignacio (Bogotá, Colombia) and receiving outpatient treatment, were analyzed. Simultaneous data from continuous glucose monitoring and capillary blood glucose were compared, and their precision and accuracy were calculating with different methods, including Clarke error grid. Analyses included 2,262 continuous glucose monitoring -reference paired glucose values. A mean absolute relative difference of 20.1% was found for all measurements, with a value higher than 23% for glucose levels ≤75mg/dL. Global compliance with the ISO criteria was 64.9%. It was higher for values >75mg/dl (68.3%, 1,308 of 1,916 readings), than for those ≤ 75mg/dl (49.4%, 171 of 346 readings). Clinical accuracy, as assessed by the Clarke error grid, showed that 91.77% of data were within the A and B zones (75.6% in hypoglycemia). A good numerical accuracy was found for continuous glucose monitoring in normo and hyperglycemia situations, with low precision in hypoglycemia. The clinical accuracy of the device was adequate, with no significant safety concerns for patients. Copyright © 2015 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Effectiveness of early intensive therapy on β-cell preservation in type 1 diabetes.

PubMed

Buckingham, Bruce; Beck, Roy W; Ruedy, Katrina J; Cheng, Peiyao; Kollman, Craig; Weinzimer, Stuart A; DiMeglio, Linda A; Bremer, Andrew A; Slover, Robert; Tamborlane, William V

2013-12-01

To assess effectiveness of inpatient hybrid closed-loop control (HCLC) followed by outpatient sensor-augmented pump (SAP) therapy initiated within 7 days of diagnosis of type 1 diabetes on the preservation of β-cell function at 1 year. Sixty-eight individuals (mean age 13.3 ± 5.7 years; 35% female, 92% Caucasian) were randomized to HCLC followed by SAP therapy (intensive group; N = 48) or to the usual-care group treated with multiple daily injections or insulin pump therapy (N = 20). Primary outcome was C-peptide concentrations during mixed-meal tolerance tests at 12 months. Intensive-group participants initiated HCLC a median of 6 days after diagnosis for a median duration of 71.3 h, during which median participant mean glucose concentration was 140 mg/dL (interquartile range 134-153 mg/dL). During outpatient SAP, continuous glucose monitor (CGM) use decreased over time, and at 12 months, only 33% of intensive participants averaged sensor use ≥6 days/week. In the usual-care group, insulin pump and CGM use were initiated prior to 12 months by 15 and 5 participants, respectively. Mean HbA1c levels were similar in both groups throughout the study. At 12 months, the geometric mean (95% CI) of C-peptide area under the curve was 0.43 (0.34-0.52) pmol/mL in the intensive group and 0.52 (0.32-0.75) pmol/mL in the usual-care group (P = 0.49). Thirty-seven (79%) intensive and 16 (80%) usual-care participants had a peak C-peptide concentration ≥0.2 pmol/mL (P = 0.30). In new-onset type 1 diabetes, HCLC followed by SAP therapy did not provide benefit in preserving β-cell function compared with current standards of care.

Low socioeconomic status is associated with adverse events in children and teens on insulin pumps under a universal access program: a population-based cohort study

PubMed Central

Shulman, Rayzel; Stukel, Therese A; Miller, Fiona A; Newman, Alice; Daneman, Denis; Wasserman, Jonathan D; Guttmann, Astrid

2016-01-01

Objective To describe adverse events in pediatric insulin pump users since universal funding in Ontario and to explore the role of socioeconomic status and 24-hour support. Research design and methods Population-based cohort study of youth (<19 years) with type 1 diabetes (n=3193) under a universal access program in Ontario, Canada, from 2006 to 2013. We linked 2012 survey data from 33 pediatric diabetes centers to health administrative databases. The relationship between patient and center-level characteristics and time to first diabetic ketoacidosis (DKA) admission or death was tested using a Cox proportional hazards model and the rate of diabetes-related emergency department visits and hospitalizations with a Poisson model, both using generalized estimating equations. Results The rate of DKA was 5.28/100 person-years and mortality 0.033/100 person-years. Compared with the least deprived quintile, the risk of DKA or death for those in the most deprived quintile was significantly higher (HR 1.58, 95% CI 1.05 to 2.38) as was the rate of diabetes-related acute care use (RR 1.60, 95% CI 1.27 to 2.00). 24-hour support was not associated with these outcomes. Higher glycated hemoglobin, prior DKA, older age, and higher nursing patient load were associated with a higher risk of DKA or death. Conclusions The safety profile of pump therapy in the context of universal funding is similar to other jurisdictions and unrelated to 24-hour support. Several factors including higher deprivation were associated with an increased risk of adverse events and could be used to inform the design of interventions aimed at preventing poor outcomes in high-risk individuals. PMID:27547416

STAR 3 randomized controlled trial to compare sensor-augmented insulin pump therapy with multiple daily injections in the treatment of type 1 diabetes: research design, methods, and baseline characteristics of enrolled subjects.

PubMed

Davis, Stephen N; Horton, Edward S; Battelino, Tadej; Rubin, Richard R; Schulman, Kevin A; Tamborlane, William V

2010-04-01

Sensor-augmented pump therapy (SAPT) integrates real-time continuous glucose monitoring (RT-CGM) with continuous subcutaneous insulin infusion (CSII) and offers an alternative to multiple daily injections (MDI). Previous studies provide evidence that SAPT may improve clinical outcomes among people with type 1 diabetes. Sensor-Augmented Pump Therapy for A1c Reduction (STAR) 3 is a multicenter randomized controlled trial comparing the efficacy of SAPT to that of MDI in subjects with type 1 diabetes. Subjects were randomized to either continue with MDI or transition to SAPT for 1 year. Subjects in the MDI cohort were allowed to transition to SAPT for 6 months after completion of the study. SAPT subjects who completed the study were also allowed to continue for 6 months. The primary end point was the difference between treatment groups in change in hemoglobin A1c (HbA1c) percentage from baseline to 1 year of treatment. Secondary end points included percentage of subjects with HbA1c < or =7% and without severe hypoglycemia, as well as area under the curve of time spent in normal glycemic ranges. Tertiary end points include percentage of subjects with HbA1c < or =7%, key safety end points, user satisfaction, and responses on standardized assessments. A total of 495 subjects were enrolled, and the baseline characteristics similar between the SAPT and MDI groups. Study completion is anticipated in June 2010. Results of this randomized controlled trial should help establish whether an integrated RT-CGM and CSII system benefits patients with type 1 diabetes more than MDI.

Synchronization software for automation in anesthesia.

PubMed

Bressan, Nadja; Castro, Ana; Brás, Susana; Oliveira, Hélder P; Ribeiro, Lénio; Ferreira, David A; Antunes, Luís; Amorim, Pedro; Nunes, Catarina S

2007-01-01

This work presents the development of a software for data acquisition and control (ASYS) on a clinical setup. Similar to the industrial Supervisory Control And Data Acquisition (SCADA) the software assembles a Target Controlled Infusion (TCI) monitoring and supervisory control data in real time from devices in a surgical room. The software is not a full controller since the TCI systems comprehend permanent interaction from the anesthesiologist. Based on pharmacokinetic models, the effect-site and plasma concentrations can be related with the drug dose infused and vice versa. The software determines the infusion rates of the drug which are given as commands to the infusion pumps. This software provides the anesthesiologist with a trustworthy tool for managing a safe and balanced anesthesia. Since it also incorporates the acquisition and display of patients brain signals.

NASA Tech Briefs, February 2004

NASA Technical Reports Server (NTRS)

2004-01-01

Topics include: Simulation Testing of Embedded Flight Software; Improved Indentation Test for Measuring Nonlinear Elasticity; Ultraviolet-Absorption Spectroscopic Biofilm Monitor; Electronic Tongue for Quantitation of Contaminants in Water; Radar for Measuring Soil Moisture Under Vegetation; Modular Wireless Data-Acquisition and Control System; Microwave System for Detecting Ice on Aircraft; Routing Algorithm Exploits Spatial Relations; Two-Finger EKG Method of Detecting Evasive Responses; Updated System-Availability and Resource-Allocation Program; Routines for Computing Pressure Drops in Venturis; Software for Fault-Tolerant Matrix Multiplication; Reproducible Growth of High-Quality Cubic-SiC Layers; Nonlinear Thermoelastic Model for SMAs and SMA Hybrid Composites; Liquid-Crystal Thermosets, a New Generation of High-Performance Liquid-Crystal Polymers; Formulations for Stronger Solid Oxide Fuel-Cell Electrolytes; Simulation of Hazards and Poses for a Rocker-Bogie Rover; Autonomous Formation Flight; Expandable Purge Chambers Would Protect Cryogenic Fittings; Wavy-Planform Helicopter Blades Make Less Noise; Miniature Robotic Spacecraft for Inspecting Other Spacecraft; Miniature Ring-Shaped Peristaltic Pump; Compact Plasma Accelerator; Improved Electrohydraulic Linear Actuators; A Software Architecture for Semiautonomous Robot Control; Fabrication of Channels for Nanobiotechnological Devices; Improved Thin, Flexible Heat Pipes; Miniature Radioisotope Thermoelectric Power Cubes; Permanent Sequestration of Emitted Gases in the Form of Clathrate Hydrates; Electrochemical, H2O2-Boosted Catalytic Oxidation System; Electrokinetic In Situ Treatment of Metal-Contaminated Soil; Pumping Liquid Oxygen by Use of Pulsed Magnetic Fields; Magnetocaloric Pumping of Liquid Oxygen; Tailoring Ion-Thruster Grid Apertures for Greater Efficiency; and Lidar for Guidance of a Spacecraft or Exploratory Robot.

Insulin during pregnancy, labour and delivery.

PubMed

de Valk, Harold W; Visser, Gerard H A

2011-02-01

Optimal glycaemic control is of the utmost importance to achieve the best possible outcome of a pregnancy complicated by diabetes. This holds for pregnancies in women with preconceptional type 1 or type 2 diabetes as well as for pregnancies complicated by gestational diabetes. Glycaemic control is conventionally expressed in the HbA1c value but the HbA1c value does not completely capture the complexity of glycaemic control. The daily glucose profile measured by the patients themselves through measurements performed in capillary blood obtained by finger stick provides valuable information needed to adjust insulin therapy. Hypoglycaemia is the major threat to the pregnant woman or the woman with tight glycaemic control in the run-up to pregnancy. Repetitive hypoglycaemia can lead to hypoglycaemia unawareness, which is reversible with prevention of hypoglycaemia. A delicate balance should be struck between preventing hyperglycaemia and hypoglycaemia. Insulin requirements are not uniform across the day: it is low during the night with a more or less pronounced rise at dawn, followed by a gradual decrease during the remainder of the day. A basal amount of insulin is needed to regulate the endogenous glucose production, short-acting insulin shots are needed to handle exogenous glucose loads. Insulin therapy means two choices: the type of insulin used and the method of insulin administration. Regarding the type of insulin, the choice is between human and analogue insulins. The analogue short-acting insulin aspart has been shown to be safe during pregnancy in a randomised trial and has received registration for this indication; the short-acting analogue insulin lispro has been shown to be safe in observational studies. No such information is available on the long-acting insulin analogues detemir and glargine and both are prescribed off-label with human long-acting insulin as obvious alternatives. Randomised trials have not been able to show superiority of continuous subcutaneous insulin administration (CSII (insulin pump)) over intensive insulin injection therapy (multiple-dose insulin (MDI)) on any maternal or foeto-neonatal end point. However, group sizes were far too small to allow assessment of superiority and issues such as manageability of the disease and quality of life were never assessed. These two issues are of major importance to patients. The first trimester is often the period of most hypoglycaemic events, and insulin therapy should be especially closely monitored and adjusted in this period. After midterm, insulin requirements increase. Continuous glucose monitoring can offer better insights into the glycaemic profile than self-monitoring of blood glucose levels by the patients but the place of these new monitoring techniques has yet to be established more clearly. Insulin therapy during labour means short-acting insulin adjusted to achieve glucose levels between 4 and 8 mmol l(-1) to prevent neonatal hypoglycaemia as much as possible. After delivery, glycaemic control must be relaxed to prevent hypoglycaemia, especially in women who breastfeed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Diabetes Cannot Be Controlled, But It Can Be Managed

DTIC Science & Technology

2017-05-05

promise that my glucose would be fine. Please keep in mind that this was before we understood insulin to carbohydrate ratios. I refused to eat anything...characterizes diabetes management as a " complex , demanding, and often confusing set of self-care directives" (p. 626). Furthermore, current notions of...lowering your pump basal rate while exercising could prevent hypoglycemia or carbohydrate counting instead of fixed dosing for meals may allow blood sugar to

Evaluation of the efficiency and reliability of software generated by code generators

NASA Technical Reports Server (NTRS)

Schreur, Barbara

1994-01-01

There are numerous studies which show that CASE Tools greatly facilitate software development. As a result of these advantages, an increasing amount of software development is done with CASE Tools. As more software engineers become proficient with these tools, their experience and feedback lead to further development with the tools themselves. What has not been widely studied, however, is the reliability and efficiency of the actual code produced by the CASE Tools. This investigation considered these matters. Three segments of code generated by MATRIXx, one of many commercially available CASE Tools, were chosen for analysis: ETOFLIGHT, a portion of the Earth to Orbit Flight software, and ECLSS and PFMC, modules for Environmental Control and Life Support System and Pump Fan Motor Control, respectively.

Continuous glucose monitoring systems for type 1 diabetes mellitus.

PubMed

Langendam, Miranda; Luijf, Yoeri M; Hooft, Lotty; Devries, J Hans; Mudde, Aart H; Scholten, Rob J P M

2012-01-18

Self-monitoring of blood glucose is essential to optimise glycaemic control in type 1 diabetes mellitus. Continuous glucose monitoring (CGM) systems measure interstitial fluid glucose levels to provide semi-continuous information about glucose levels, which identifies fluctuations that would not have been identified with conventional self-monitoring. Two types of CGM systems can be defined: retrospective systems and real-time systems. Real-time systems continuously provide the actual glucose concentration on a display. Currently, the use of CGM is not common practice and its reimbursement status is a point of debate in many countries. To assess the effects of CGM systems compared to conventional self-monitoring of blood glucose (SMBG) in patients with diabetes mellitus type 1. We searched The Cochrane Library, MEDLINE, EMBASE and CINAHL for the identification of studies. Last search date was June 8, 2011. Randomised controlled trials (RCTs) comparing retrospective or real-time CGM with conventional self-monitoring of blood glucose levels or with another type of CGM system in patients with type 1 diabetes mellitus. Primary outcomes were glycaemic control, e.g. level of glycosylated haemoglobin A1c (HbA1c) and health-related quality of life. Secondary outcomes were adverse events and complications, CGM derived glycaemic control, death and costs. Two authors independently selected the studies, assessed the risk of bias and performed data-extraction. Although there was clinical and methodological heterogeneity between studies an exploratory meta-analysis was performed on those outcomes the authors felt could be pooled without losing clinical merit. The search identified 1366 references. Twenty-two RCTs meeting the inclusion criteria of this review were identified. The results of the meta-analyses (across all age groups) indicate benefit of CGM for patients starting on CGM sensor augmented insulin pump therapy compared to patients using multiple daily injections of insulin (MDI) and standard monitoring blood glucose (SMBG). After six months there was a significant larger decline in HbA1c level for real-time CGM users starting insulin pump therapy compared to patients using MDI and SMBG (mean difference (MD) in change in HbA1c level -0.7%, 95% confidence interval (CI) -0.8% to -0.5%, 2 RCTs, 562 patients, I(2)=84%). The risk of hypoglycaemia was increased for CGM users, but CIs were wide and included unity (4/43 versus 1/35; RR 3.26, 95% CI 0.38 to 27.82 and 21/247 versus 17/248; RR 1.24, 95% CI 0.67 to 2.29). One study reported the occurrence of ketoacidosis from baseline to six months; there was however only one event. Both RCTs were in patients with poorly controlled diabetes.For patients starting with CGM only, the average decline in HbA1c level six months after baseline was also statistically significantly larger for CGM users compared to SMBG users, but much smaller than for patients starting using an insulin pump and CGM at the same time (MD change in HbA1c level -0.2%, 95% CI -0.4% to -0.1%, 6 RCTs, 963 patients, I(2)=55%). On average, there was no significant difference in risk of severe hypoglycaemia or ketoacidosis between CGM and SMBG users. The confidence interval however, was wide and included a decreased as well as an increased risk for CGM users compared to the control group (severe hypoglycaemia: 36/411 versus 33/407; RR 1.02, 95% CI 0.65 to 1.62, 4 RCTs, I(2)=0% and ketoacidosis: 8/411 versus 8/407; RR 0.94, 95% CI 0.36 to 2.40, 4 RCTs, I(2)=0%).Health-related quality of life was reported in five of the 22 studies. In none of these studies a significant difference between CGM and SMBG was found. Diabetes complications, death and costs were not measured.There were no studies in pregnant women with diabetes type 1 and in patients with hypoglycaemia unawareness. There is limited evidence for the effectiveness of real-time continuous glucose monitoring (CGM) use in children, adults and patients with poorly controlled diabetes. The largest improvements in glycaemic control were seen for sensor-augmented insulin pump therapy in patients with poorly controlled diabetes who had not used an insulin pump before. The risk of severe hypoglycaemia or ketoacidosis was not significantly increased for CGM users, but as these events occurred infrequent these results have to be interpreted cautiously.There are indications that higher compliance of wearing the CGM device improves glycosylated haemoglobin A1c level (HbA1c) to a larger extent. 

Low threshold diode-pumped picosecond mode-locked Nd:YAG laser with a semiconductor saturable absorber mirror

NASA Astrophysics Data System (ADS)

Eshghi, M. J.; Majdabadi, A.; Koohian, A.

2017-01-01

In this paper, a low threshold diode pumped passively mode-locked Nd:YAG laser has been demonstrated by using a semiconductor saturable absorber mirror. The threshold power for continuous-wave mode-locking is relatively low, about 3.2 W. The resonator stability across the pump power has been analytically examined. Moreover, the mode overlap between the pump beam and the laser fundamental mode has been simulated by MATLAB software. Adopting Z-shaped resonator configuration and suitable design of the resonator’s arm lengths, has enabled the author to prepare mode-locking conditions, and obtain 40 ps pulses with 112 MHz pulse repetition rate. The laser output was stable without any Q switched instability. To the best of our knowledge, this is the lowest threshold for CW mode-locking operation of a Nd:YAG laser.

A day in the life of a diabetic diver: the Undersea and Hyperbaric Medical Society/Divers Alert Network protocol for diving with diabetes in action.

PubMed

Johnson, Rebecca

2016-09-01

Some people with well-managed insulin-dependent diabetes can dive safely. Those cleared to participate should control tightly the variables that impact blood glucose levels, including activity, timing, food and insulin. Honest self-assessment is critical. A diabetic diver should cancel a dive if seasick, unusually anxious, or following significant high or low blood glucose levels in the preceding 24 hours. The diver should enter the water with a blood glucose level above 8.3 mmol·L⁻¹ and below 14 mmol·L⁻¹ with a stable or rising trend in blood glucose established with glucose tests at 90, 60, and 30 minutes prior to a dive. The diver should carry emergency glucose at all times and brief dive buddies about hypoglycaemia procedures. This is a personal account of the author's experience diving with type 1 diabetes and details how the UHMS/DAN recommendations are put into practice on dive days. Key elements of the self-assessment process, long- and rapid-acting insulin adjustments, meal timing, responses to blood glucose trends, handling hypoglycaemia and approaching multi-dive days are described. Some considerations for people using insulin pumps are also briefly discussed.

A multicentre randomized controlled trial of an empowerment-inspired intervention for adolescents starting continuous subcutaneous insulin infusion--a study protocol.

PubMed

Brorsson, Anna Lena; Leksell, Janeth; Viklund, Gunnel; Lindholm Olinder, Anna

2013-12-20

Continuous subcutaneous insulin infusion (CSII) treatment among children with type 1 diabetes is increasing in Sweden. However, studies evaluating glycaemic control in children using CSII show inconsistent results. The distribution of responsibility for diabetes self-management between children and parents is often unclear and needs clarification. There is much published support for continued parental involvement and shared diabetes management during adolescence. Guided Self-Determination (GSD) is an empowerment-based, person-centred, reflection and problem solving method intended to guide the patient to become self-sufficient and develop life skills for managing difficulties in diabetes self-management. This method has been adapted for adolescents and parents as Guided Self-Determination-Young (GSD-Y). This study aims to evaluate the effect of an intervention with GSD-Y in groups of adolescents starting on insulin pumps and their parents on diabetes-related family conflicts, perceived health and quality of life (QoL), and metabolic control. Here, we describe the protocol and plans for study enrollment. This study is designed as a randomized, controlled, prospective, multicentre study. Eighty patients between 12-18 years of age who are planning to start CSII will be included. All adolescents and their parents will receive standard insulin pump training. The education intervention will be conducted when CSII is to be started and at four appointments in the first 4 months after starting CSII. The primary outcome is haemoglobin A1c levels. Secondary outcomes are perceived health and QoL, frequency of blood glucose self-monitoring and bolus doses, and usage of carbohydrate counting. The following instruments will be used: Disabkids, 'Check your health', the Diabetes Family Conflict Scale and the Swedish Diabetes Empowerment Scale. Outcomes will be evaluated within and between groups by comparing data at baseline, and at 6 and 12 months after starting treatment. In this study, we will assess the effect of starting an CSII together with the model of GSD to determine whether this approach leads to retention of improved glycaemic control, QoL, responsibility distribution and reduced diabetes-related conflicts in the family.

Regulation of ENaC-mediated alveolar fluid clearance by insulin via PI3K/Akt pathway in LPS-induced acute lung injury.

PubMed

Deng, Wang; Li, Chang-Yi; Tong, Jin; Zhang, Wei; Wang, Dao-Xin

2012-03-30

Stimulation of epithelial sodium channel (ENaC) increases Na(+) transport, a driving force of alveolar fluid clearance (AFC) to keep alveolar spaces free of edema fluid that is beneficial for acute lung injury (ALI). It is well recognized that regulation of ENaC by insulin via PI3K pathway, but the mechanism of this signaling pathway to regulate AFC and ENaC in ALI remains unclear. The aim of this study was to investigate the effect of insulin on AFC in ALI and clarify the pathway in which insulin regulates the expression of ENaC in vitro and in vivo. A model of ALI (LPS at a dose of 5.0 mg/kg) with non-hyperglycemia was established in Sprague-Dawley rats receiving continuous exogenous insulin by micro-osmotic pumps and wortmannin. The lungs were isolated for measurement of bronchoalveolar lavage fluid(BALF), total lung water content(TLW), and AFC after ALI for 8 hours. Alveolar epithelial type II cells were pre-incubated with LY294002, Akt inhibitor and SGK1 inhibitor 30 minutes before insulin treatment for 2 hours. The expressions of α-,β-, and γ-ENaC were detected by immunocytochemistry, reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. In vivo, insulin decreased TLW, enchanced AFC, increased the expressions of α-,β-, and γ-ENaC and the level of phosphorylated Akt, attenuated lung injury and improved the survival rate in LPS-induced ALI, the effects of which were blocked by wortmannin. Amiloride, a sodium channel inhibitor, significantly reduced insulin-induced increase in AFC. In vitro, insulin increased the expressions of α-,β-, and γ-ENaC as well as the level of phosphorylated Akt but LY294002 and Akt inhibitor significantly prevented insulin-induced increase in the expression of ENaC and the level of phosphorylated Akt respectively. Immunoprecipitation studies showed that levels of Nedd4-2 binding to ENaC were decreased by insulin via PI3K/Akt pathway. Our study demonstrated that insulin alleviated pulmonary edema and enhanced AFC by increasing the expression of ENaC that dependent upon PI3K/Akt pathway by inhibition of Nedd4-2.

Vane Pump Casing Machining of Dumpling Machine Based on CAD/CAM

NASA Astrophysics Data System (ADS)

Huang, Yusen; Li, Shilong; Li, Chengcheng; Yang, Zhen

Automatic dumpling forming machine is also called dumpling machine, which makes dumplings through mechanical motions. This paper adopts the stuffing delivery mechanism featuring the improved and specially-designed vane pump casing, which can contribute to the formation of dumplings. Its 3D modeling in Pro/E software, machining process planning, milling path optimization, simulation based on UG and compiling post program were introduced and verified. The results indicated that adoption of CAD/CAM offers firms the potential to pursue new innovative strategies.

Commentary on “Performance of a Glucose Meter with a Built-In Automated Bolus Calculator versus Manual Bolus Calculation in Insulin-Using Subjects”

PubMed Central

Rossetti, Paolo; Vehí, Josep; Revert, Ana; Calm, Remei; Bondia, Jorge

2012-01-01

Since the early 2000s, there has been an exponentially increasing development of new diabetes-applied technology, such as continuous glucose monitoring, bolus calculators, and “smart” pumps, with the expectation of partially overcoming clinical inertia and low patient compliance. However, its long-term efficacy in glucose control has not been unequivocally proven. In this issue of Journal of Diabetes Science and Technology, Sussman and colleagues evaluated a tool for the calculation of the prandial insulin dose. A total of 205 insulin-treated patients were asked to compute a bolus dose in two simulated conditions either manually or with the bolus calculator built into the FreeStyle InsuLinx meter, revealing the high frequency of wrong calculations when performed manually. Although the clinical impact of this study is limited, it highlights the potential implications of low diabetes-related numeracy in poor glycemic control. Educational programs aiming to increase patients’ empowerment and caregivers’ knowledge are needed in order to get full benefit of the technology. PMID:22538145

Managing type 1 diabetes in school: Recommendations for policy and practice

PubMed Central

Lawrence, Sarah E; Cummings, Elizabeth A; Pacaud, Danièle; Lynk, Andrew; Metzger, Daniel L

2015-01-01

Diabetes requiring insulin is increasingly common and likely to impact students in most, if not all, schools. Diabetes and its complications have major personal, social and economic impact, and improved diabetes control reduces the risk of both short- and long-term complications. Evidence shows that more intensive management of diabetes – through frequent blood glucose monitoring, insulin administration with injections and/or insulin pumps, and careful attention to diet and exercise – leads to better control. Since children spend 30 to 35 hours per week at school, effectively managing their diabetes while there is integral to their short- and long-term health. The Canadian Paediatric Society and the Canadian Pediatric Endocrine Group recommend that minimum standards for supervision and care be established across Canada to support children and youth with type 1 diabetes in schools. These recommendations are derived from evidence-based clinical practice guidelines, with input from diabetes care providers from across Canada, and are consistent with the Canadian Diabetes Association’s Guidelines for the Care of Students Living with Diabetes at School. PMID:25722642

Programmable control means for providing safe and controlled medication infusion

NASA Technical Reports Server (NTRS)

Fischell, Robert E. (Inventor)

1988-01-01

An implantable programmable infusion pump (IPIP) is disclosed and generally includes: a fluid reservoir filled with selected medication; a pump for causing a precise volumetric dosage of medication to be withdrawn from the reservoir and delivered to the appropriate site within the body; and, a control means for actuating the pump in a safe and programmable manner. The control means includes a microprocessor, a permanent memory containing a series of fixed software instructions, and a memory for storing prescription schedules, dosage limits and other data. The microprocessor actuates the pump in accordance with programmable prescription parameters and dosage limits stored in the memory. A communication link allows the control means to be remotely programmed. The control means incorporates a running integral dosage limit and other safety features which prevent an inadvertent or intentional medication overdose. The control means also monitors the pump and fluid handling system and provides an alert if any improper or potentially unsafe operation is detected.

The Apical Localization of Na+, K+-ATPase in Cultured Human Retinal Pigment Epithelial Cells Depends on Expression of the β2 Subunit

PubMed Central

Lobato-Álvarez, Jorge A.; Roldán, María L.; López-Murillo, Teresa del Carmen; González-Ramírez, Ricardo; Bonilla-Delgado, José; Shoshani, Liora

2016-01-01

Na+, K+-ATPase, or the Na+ pump, is a key component in the maintenance of the epithelial phenotype. In most epithelia, the pump is located in the basolateral domain. Studies from our laboratory have shown that the β1 subunit of Na+, K+-ATPase plays an important role in this mechanism because homotypic β1-β1 interactions between neighboring cells stabilize the pump in the lateral membrane. However, in the retinal pigment epithelium (RPE), the Na+ pump is located in the apical domain. The mechanism of polarization in this epithelium is unclear. We hypothesized that the apical polarization of the pump in RPE cells depends on the expression of its β2 subunit. ARPE-19 cells cultured for up to 8 weeks on inserts did not polarize, and Na+, K+-ATPase was expressed in the basolateral membrane. In the presence of insulin, transferrin and selenic acid (ITS), ARPE-19 cells cultured for 4 weeks acquired an RPE phenotype, and the Na+ pump was visible in the apical domain. Under these conditions, Western blot analysis was employed to detect the β2 isoform and immunofluorescence analysis revealed an apparent apical distribution of the β2 subunit. qPCR results showed a time-dependent increase in the level of β2 isoform mRNA, suggesting regulation at the transcriptional level. Moreover, silencing the expression of the β2 isoform in ARPE-19 cells resulted in a decrease in the apical localization of the pump, as assessed by the mislocalization of the α2 subunit in that domain. Our results demonstrate that the apical polarization of Na+, K+-ATPase in RPE cells depends on the expression of the β2 subunit. PMID:27774068

The Apical Localization of Na+, K+-ATPase in Cultured Human Retinal Pigment Epithelial Cells Depends on Expression of the β2 Subunit.

PubMed

Lobato-Álvarez, Jorge A; Roldán, María L; López-Murillo, Teresa Del Carmen; González-Ramírez, Ricardo; Bonilla-Delgado, José; Shoshani, Liora

2016-01-01

Na + , K + -ATPase, or the Na + pump, is a key component in the maintenance of the epithelial phenotype. In most epithelia, the pump is located in the basolateral domain. Studies from our laboratory have shown that the β 1 subunit of Na + , K + -ATPase plays an important role in this mechanism because homotypic β 1 -β 1 interactions between neighboring cells stabilize the pump in the lateral membrane. However, in the retinal pigment epithelium (RPE), the Na + pump is located in the apical domain. The mechanism of polarization in this epithelium is unclear. We hypothesized that the apical polarization of the pump in RPE cells depends on the expression of its β 2 subunit. ARPE-19 cells cultured for up to 8 weeks on inserts did not polarize, and Na + , K + -ATPase was expressed in the basolateral membrane. In the presence of insulin, transferrin and selenic acid (ITS), ARPE-19 cells cultured for 4 weeks acquired an RPE phenotype, and the Na + pump was visible in the apical domain. Under these conditions, Western blot analysis was employed to detect the β 2 isoform and immunofluorescence analysis revealed an apparent apical distribution of the β 2 subunit. qPCR results showed a time-dependent increase in the level of β 2 isoform mRNA, suggesting regulation at the transcriptional level. Moreover, silencing the expression of the β 2 isoform in ARPE-19 cells resulted in a decrease in the apical localization of the pump, as assessed by the mislocalization of the α 2 subunit in that domain. Our results demonstrate that the apical polarization of Na + , K + -ATPase in RPE cells depends on the expression of the β 2 subunit.

Continuous subcutaneous insulin infusion versus multiple daily injections of insulin for pregnant women with diabetes.

PubMed

Farrar, Diane; Tuffnell, Derek J; West, Jane; West, Helen M

2016-06-07

Diabetes results in a rise in blood glucose above normal physiological levels; if untreated this may cause damage to many systems including the cardiovascular and renal systems. Pregnancy increases resistance to insulin action; for those women who have pre-gestational diabetes, this results in an increasing insulin requirement. There are several methods of administering insulin. Conventionally, insulin has been administered subcutaneously, formally referred to as intensive conventional treatment, but now more usually referred to as multiple daily injections (MDI). An alternative method of insulin administration is the continuous subcutaneous insulin infusion pump (CSII). To compare CSII with MDI of insulin for pregnant women with pre-existing and gestational diabetes. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2016) and reference lists of retrieved studies. Randomised trials comparing CSII with MDI for pregnant women with diabetes. Three review authors independently assessed studies and two review authors extracted data. Disagreements were resolved through discussion with the third author. We assessed the quality of the evidence using the GRADE approach. We included five single-centre trials (undertaken in Italy) with 153 women and 154 pregnancies in this review.There were no clear differences in the primary outcomes reported between CSII and MDI in the included trials: caesarean section (risk ratio (RR) 1.09, 95% confidence interval (CI) 0.66 to 1.77; three trials, 71 women, evidence graded very low), large-for-gestational age (RR 4.15, 95% CI 0.49 to 34.95; three trials, 73 infants; evidence graded very low), and perinatal mortality (RR 2.33, 95% CI 0.38 to 14.32; four trials, 83 infants, evidence graded very low). Other primary outcomes were not reported in these trials (hypertensive disorders of pregnancy, development of type 2 diabetes, composite outcome of serious neonatal outcomes, and neurosensory disability).There was no clear evidence of differences in the maternal secondary outcomes: maternal weight gain during pregnancy, 24 hour mean blood glucose in each trimester, mean maternal HbA1c in each trimester, maternal hypoglycaemia, and maternal hyperglycaemia. The included studies did not report several GRADE outcomes: perineal trauma, return to pre-pregnancy weight, postnatal depression, induction of labour. Many maternal secondary outcomes were also not reported.In two trials, including a total of 61 infants, CSII was associated with an increase in mean birthweight compared with MDI (mean difference (MD) 220.56 g, 95% CI -2.09 g to 443.20 g; P = 0.05). However, the large CI including anything from a small reduction to an increase in mean birthweight and the lack of a difference in macrosomia rate (RR 3.20, CI 0.14 to 72.62; two trials, 61 infants) suggests uncertainty. Large-for-gestational age (see above), andsmall-for-gestational age also suggests uncertainty of effect. No significant differences were found in: gestation at delivery, preterm birth < 37 weeks' gestation, preterm birth < 32 weeks' gestation, neonatal hypoglycaemia (evidence graded very low), respiratory distress syndrome, neonatal hyperbilirubinaemia, and fetal anomaly. There were no data reported on many important infant outcomes, including the GRADE outcomes adiposity and diabetes. There was no follow-up of infants in childhood or adulthood, so longer-term outcomes were not reported.The only outcome reported for use of health service resources wasmaternal days hospitalised, which did not show a difference between groups in the small number of women included (MD 9.40, CI -6.04 to 24.84; one trial, 10 women).The methods used by the trials were poorly reported, for example although blinding of participants and clinicians regarding intervention allocation is impossible, it is possible to blind assessors and this along with other aspects of trial methods was not reported, which means that the trials are at an unclear or high risk of bias. We do not know if the women who participated were representative, and therefore if the results can be generalised. Most GRADE outcomes were not reported. For the GRADE outcomes that were reported, our assessment was that the evidence is very low quality (caesarean section, large-for-gestational age, perinatal mortality, andneonatal hypoglycaemia). This was due to design limitations in the included trials, small sample sizes in the trials contributing data, wide CIs crossing both the line of no effect and the line of appreciable benefit and/or harm, and often few events. We are therefore uncertain whether CSII or MDI improves outcomes for pregnant women with diabetes and their infants, and the results of further studies may differ substantially from those presented in this review. There is no evidence to support the use of one particular form of insulin administration over another for pregnant women with diabetes. There are only a small number of trials appropriate for meta-analysis, a small number of women included and questionable generalisability of the trial population.Pump technology has progressed since these trials were undertaken. Well-designed randomised trials are required to evaluate comparisons such as patch pumps against MDI and more conventional CSII against MDI. These trials should be adequately powered to assess the effect of interventions, and report the core set of outcomes used in Cochrane reviews of diabetes in pregnancy. Trials to assess the effects of pumps on birthweight and macrosomia rates are needed. It would be beneficial for future trials to undertake longer-term follow-up of participants and their infants, assess women's preferences, and conduct an economic evaluation.

A performance improvement plan to increase nurse adherence to use of medication safety software.

PubMed

Gavriloff, Carrie

2012-08-01

Nurses can protect patients receiving intravenous (IV) medication by using medication safety software to program "smart" pumps to administer IV medications. After a patient safety event identified inconsistent use of medication safety software by nurses, a performance improvement team implemented the Deming Cycle performance improvement methodology. The combined use of improved direct care nurse communication, programming strategies, staff education, medication safety champions, adherence monitoring, and technology acquisition resulted in a statistically significant (p < .001) increase in nurse adherence to using medication safety software from 28% to above 85%, exceeding national benchmark adherence rates (Cohen, Cooke, Husch & Woodley, 2007; Carefusion, 2011). Copyright © 2012 Elsevier Inc. All rights reserved.

Industrial energy systems and assessment opportunities

NASA Astrophysics Data System (ADS)

Barringer, Frank Leonard, III

Industrial energy assessments are performed primarily to increase energy system efficiency and reduce energy costs in industrial facilities. The most common energy systems are lighting, compressed air, steam, process heating, HVAC, pumping, and fan systems, and these systems are described in this document. ASME has produced energy assessment standards for four energy systems, and these systems include compressed air, steam, process heating, and pumping systems. ASHRAE has produced an energy assessment standard for HVAC systems. Software tools for energy systems were developed for the DOE, and there are software tools for almost all of the most common energy systems. The software tools are AIRMaster+ and LogTool for compressed air systems, SSAT and 3E Plus for steam systems, PHAST and 3E Plus for process heating systems, eQUEST for HVAC systems, PSAT for pumping systems, and FSAT for fan systems. The recommended assessment procedures described in this thesis are used to set up an energy assessment for an industrial facility, collect energy system data, and analyze the energy system data. The assessment recommendations (ARs) are opportunities to increase efficiency and reduce energy consumption for energy systems. A set of recommended assessment procedures and recommended assessment opportunities are presented for each of the most common energy systems. There are many assessment opportunities for industrial facilities, and this thesis describes forty-three ARs for the seven different energy systems. There are seven ARs for lighting systems, ten ARs for compressed air systems, eight ARs for boiler and steam systems, four ARs for process heating systems, six ARs for HVAC systems, and four ARs for both pumping and fan systems. Based on a history of past assessments, average potential energy savings and typical implementation costs are shared in this thesis for most ARs. Implementing these ARs will increase efficiency and reduce energy consumption for energy systems in industrial facilities. This thesis does not explain all energy saving ARs that are available, but does describe the most common ARs.

Identification and Quantitative Measurements of Chemical Species by Mass Spectrometry

NASA Technical Reports Server (NTRS)

Zondlo, Mark A.; Bomse, David S.

2005-01-01

The development of a miniature gas chromatograph/mass spectrometer system for the measurement of chemical species of interest to combustion is described. The completed system is a fully-contained, automated instrument consisting of a sampling inlet, a small-scale gas chromatograph, a miniature, quadrupole mass spectrometer, vacuum pumps, and software. A pair of computer-driven valves controls the gas sampling and introduction to the chromatographic column. The column has a stainless steel exterior and a silica interior, and contains an adsorbent of that is used to separate organic species. The detection system is based on a quadrupole mass spectrometer consisting of a micropole array, electrometer, and a computer interface. The vacuum system has two miniature pumps to maintain the low pressure needed for the mass spectrometer. A laptop computer uses custom software to control the entire system and collect the data. In a laboratory demonstration, the system separated calibration mixtures containing 1000 ppm of alkanes and alkenes.

Incorporating a Generic Model of Subcutaneous Insulin Absorption into the AIDA v4 Diabetes Simulator 3. Early Plasma Insulin Determinations

PubMed Central

Lehmann, Eldon D.; Tarín, Cristina; Bondia, Jorge; Teufel, Edgar; Deutsch, Tibor

2009-01-01

Introduction AIDA is an interactive educational diabetes simulator that has been available without charge via the Internet for over 12 years. Recent articles have described the incorporation of a novel generic model of insulin absorption into AIDA as a way of enhancing its capabilities. The basic model components to be integrated have been overviewed, with the aim being to provide simulations of regimens utilizing insulin analogues, as well as insulin doses greater than 40 IU (the current upper limit within the latest release of AIDA [v4.3a]). Some preliminary calculated insulin absorption results have also recently been described. Methods This article presents the first simulated plasma insulin profiles from the integration of the generic subcutaneous insulin absorption model, and the currently implemented model in AIDA for insulin disposition. Insulin absorption has been described by the physiologically based model of Tarín and colleagues. A single compartment modeling approach has been used to specify how absorbed insulin is distributed in, and eliminated from, the human body. To enable a numerical solution of the absorption model, a spherical subcutaneous depot for the injected insulin dose has been assumed and spatially discretized into shell compartments with homogeneous concentrations, having as its center the injection site. The number of these compartments will depend on the dose and type of insulin. Insulin inflow arises as the sum of contributions to the different shells. For this report the first bench testing of plasma insulin determinations has been done. Results Simulated plasma insulin profiles are provided for currently available insulin preparations, including a rapidly acting insulin analogue (e.g., lispro/Humalog or aspart/Novolog), a short-acting (regular) insulin preparation (e.g., Actrapid), intermediate-acting insulins (both Semilente and neutral protamine Hagedorn types), and a very long-acting insulin analogue (e.g., glargine/Lantus), as well as for insulin doses up to 50 IU. Discussion The methodology to be adopted for implementing the generic absorption model within AIDA has been overviewed, and the first plasma insulin profiles based on this approach have been demonstrated. Ideas for future work and development are discussed. It is expected that an updated release of AIDA (v4.5), based on this collaborative approach, will become available for free—in due course—via the www.2aida.org Web site. Readers who wish to be informed when the new software is launched can join the very low volume AIDA announcement list by sending a blank email note to subscribe@2aida.org. PMID:20046665

OpT2mise: a randomized controlled trial to compare insulin pump therapy with multiple daily injections in the treatment of type 2 diabetes-research design and methods.

PubMed

Aronson, Ronnie; Cohen, Ohad; Conget, Ignacio; Runzis, Sarah; Castaneda, Javier; de Portu, Simona; Lee, Scott; Reznik, Yves

2014-07-01

In insulin-requiring type 2 diabetes patients, current insulin therapy approaches such as basal-alone or basal-bolus multiple daily injections (MDI) have not consistently provided achievement of optimal glycemic control. Previous studies have suggested a potential benefit of continuous subcutaneous insulin infusion (CSII) in these patients. The OpT2mise study is a multicenter, randomized, trial comparing CSII with MDI in a large cohort of subjects with evidence of persistent hyperglycemia despite previous MDI therapy. Subjects were enrolled into a run-in period for optimization of their MDI insulin regimen. Subjects showing persistent hyperglycemia (glycated hemoglobin [HbA1c] ≥8% and ≤12%) were then randomly assigned to CSII or continuing an MDI regimen for a 6-month phase followed by a single crossover of the MDI arm, switching to CSII. The primary end point is the between-group difference in mean change in HbA1c from baseline to 6 months. Secondary end points include change in mean 24-h glucose values, area under the curve and time spent in hypoglycemia and hyperglycemia, measures of glycemic excursions, change in postprandial hyperglycemia, and evaluation of treatment satisfaction. Safety end points include hypoglycemia, hospital admissions, and emergency room visits. When subject enrollment was completed in May 2013, 495 subjects had been enrolled in the study. The study completion for the primary end point is expected in January 2014. OpT2mise will represent the largest studied homogeneous cohort of type 2 diabetes patients with persistent hyperglycemia despite optimized MDI therapy. OpT2mise will help define the role of CSII in insulin intensification and define its safety, rate of hypoglycemia, patient adherence, and patient satisfaction.

A multivariate model exploring the predictive value of demographic, adolescent, and family factors on glycemic control in adolescents with type 1 diabetes.

PubMed

Agarwal, Shivani; Jawad, Abbas F; Miller, Victoria A

2016-11-01

The current study examined how a comprehensive set of variables from multiple domains, including at the adolescent and family level, were predictive of glycemic control in adolescents with type 1 diabetes (T1D). Participants included 100 adolescents with T1D ages 10-16 yrs and their parents. Participants were enrolled in a longitudinal study about youth decision-making involvement in chronic illness management of which the baseline data were available for analysis. Bivariate associations with glycemic control (HbA1C) were tested. Hierarchical linear regression was implemented to inform the predictive model. In bivariate analyses, race, family structure, household income, insulin regimen, adolescent-reported adherence to diabetes self-management, cognitive development, adolescent responsibility for T1D management, and parent behavior during the illness management discussion were associated with HbA1c. In the multivariate model, the only significant predictors of HbA1c were race and insulin regimen, accounting for 17% of the variance. Caucasians had better glycemic control than other racial groups. Participants using pre-mixed insulin therapy and basal-bolus insulin had worse glycemic control than those on insulin pumps. This study shows that despite associations of adolescent and family-level variables with glycemic control at the bivariate level, only race and insulin regimen are predictive of glycemic control in hierarchical multivariate analyses. This model offers an alternative way to examine the relationship of demographic and psychosocial factors on glycemic control in adolescents with T1D. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Research of working pulsation in closed angle based on rotating-sleeve distributing-flow system

NASA Astrophysics Data System (ADS)

Zhang, Yanjun; Zhang, Hongxin; Zhao, Qinghai; Jiang, Xiaotian; Cheng, Qianchang

2017-08-01

In order to reduce negative effects including hydraulic impact, noise and mechanical vibration, compression and expansion of piston pump in closed volume are used to optimize the angle between valve port and chamber. In addition, the mathematical model about pressurization and depressurization in pump chamber are analyzed based on distributing-flow characteristic, and it is necessary to use simulation software Fluent to simulate the distributing-flow fluid model so as to select the most suitable closed angle. As a result, when compression angle is 3°, the angle is closest to theoretical analysis and has the minimum influence on flow and pump pressure characteristic. Meanwhile, cavitation phenomenon appears in pump chamber in different closed angle on different degrees. Besides the flow pulsation is increasingly smaller with increasing expansion angle. Thus when expansion angle is 2°, the angle is more suitable for distributing-flow system.

Numerical simulation on the cavitation of waterjet propulsion pump

NASA Astrophysics Data System (ADS)

Xia, C. Z.; Cheng, L.; Shang, Y. N.; Zhou, J. R.; Yang, F.; Jin, Y.

2016-05-01

Waterjet propulsion system is widely used in high speed vessels with advantages of simple transmission mechanism, low noise underwater and good manoeuvrability. Compared with the propeller, waterjet propulsion can be used flow stamping to increasing cavitation resistance at high speed. But under certain conditions, such as low ship speed or high ship speed, cavitation problem still exists. If water-jet propulsion pump is run in cavitation condition for a long time, then the cavitation will cause a great deal of noise CFD is applied to analysis and predict the process of production and development of cavitation in waterjet propulsion pump. Based on the cavitation model of Zwart-Gerber-Belamri and a mixture of homogeneous flow model, commercial CFD software CFX was taken for characteristics of cavitation under the three operating conditions. Commercial software ANSYS 14.0 is used to build entity model, mesh and numerical simulation. The grid independence analysis determine the grid number of mixed flow pump model is about 1.6 million and the grid number of water-jet pump system unit is about 2.7 million. The cavitation characteristics of waterjet pump under three operating conditions are studied. The results show that the cavitation development trend is similar design and small rate of flow condition .Under the design conditions Cavitation bubbles are mainly gathered in suction surface of blade near the inlet side of the hub under the primary stage, and gradually extended to the water side in the direction of the rim with the loss of the inlet total pressure. Cavitation appears in hub before the blade rim, but the maximum value of gas content in blade rim is bigger than that in hub. Under large flow conditions, bubble along the direction of wheel hub extends to the rim gradually. Cavitation is found in the pressure surface of blade near the hub region under the critical point of cavitation nearby. When NPSHa is lower than critical point, the area covering by bubbles is about 40% in the suction surface of blade. It means that the critical point of cavitation of pump system is not the accrue point of install cavitation but cavitation has been developed to a certain stage.

Computer controlled fluorometer device and method of operating same

DOEpatents

Kolber, Z.; Falkowski, P.

1990-07-17

A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means. 13 figs.

Computer controlled fluorometer device and method of operating same

DOEpatents

Kolber, Zbigniew; Falkowski, Paul

1990-01-01

A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means.

Shuttle avionics software trials, tribulations and success

NASA Technical Reports Server (NTRS)

Henderson, O. L.

1985-01-01

The early problems and the solutions developed to provide the required quality software needed to support the space shuttle engine development program are described. The decision to use a programmable digital control system on the space shuttle engine was primarily based upon the need for a flexible control system capable of supporting the total engine mission on a large complex pump fed engine. The mission definition included all control phases from ground checkout through post shutdown propellant dumping. The flexibility of the controller through reprogrammable software allowed the system to respond to the technical challenges and innovation required to develop both the engine and controller hardware. This same flexibility, however, placed a severe strain on the capability of the software development and verification organization. The overall development program required that the software facility accommodate significant growth in both the software requirements and the number of software packages delivered. This challenge was met by reorganization and evolution in the process of developing and verifying software.

Silicon micromachined pumps employing piezoelectric membrane actuation for microfluidic systems

NASA Astrophysics Data System (ADS)

Koch, Michael

Microsystems technology is a rapidly expanding area that comprises electronics, mechanics and optics. In this field, physical/chemical sensing, fluid handling and optical communication are emerging as potential markets. Microfluidic systems like an implantable insulin pump, a drug delivery system and a total chemical analysis system are currently being developed by academia and industry around the world. This project contributes to the area of microfluidics in that a novel thick-film-on-silicon membrane actuator has been developed to allow inexpensive mass production of micropumps. To date piezoelectric plates have been surface mounted onto a silicon membrane. This single chip fabrication method can now be replaced by screen printing thick piezoelectric layers onto 4 inch silicon substrates. Two different pump types have been developed. These are membrane pumps with either cantilever valves or diffuser/nozzle valves. Pump rates between 100 and 200 μl min-1 and backpressures up to 4 kPa have been achieved with these pumps. Along with the technology of micropumps, simulators have been developed. A novel coupled FEM-CFD solver was realised by a computer controlled coupling of two commercially available packages (ANSYS and CFX-Flow3D). The results of this simulator were in good agreement with measurements on micromachined cantilever valves. CFX- Flow3D was also used to successfully model the behaviour of the diffuser/nozzle valve. Finally, the pump has been simulated using a continuity equation. A behavioural dynamic extension of the cantilever valve was necessary to achieve better prediction of the pump rates for higher frequencies. As well, a common process has been developed for microfluidic devices like micromixers, particle counters and sorters as well as flow sensors. The micromixer has been tested already and achieves mixing for input pressures between 2 and 7 kPa. This agrees with simulations of the diffusive mixing with CFX-Flow3D. Together with the micropump, a combination of these devices allows future development of microfluidic systems for the medical and (bio)chemical market.

Development and Optimized Design of Propeller Pump System & Structure with VFD in Low-head Pumping Station

NASA Astrophysics Data System (ADS)

Rentian, Zhang; Honggeng, Zhu; Arnold, Jaap; Linbi, Yao

2010-06-01

Compared with vertical-installed pumps, the propeller (bulb tubular) pump systems can achieve higher hydraulic efficiencies, which are particularly suitable for low-head pumping stations. More than four propeller pumping stations are being, or will be built in the first stage of the S-to-N Water Diversion Project in China, diverting water from Yangtze River to the northern part of China to alleviate water-shortage problems and develop the economy. New structures of propeller pump have been developed for specified pumping stations in Jiangsu and Shandong Provinces respectively and Variable Frequency Drives (VFDs) are used in those pumping stations to regulate operating conditions. Based on the Navier-Stokes equations and the standard k-e turbulent model, numerical simulations of the flow field and performance prediction in the propeller pump system were conducted on the platform of commercial software CFX by using the SIMPLEC algorithm. Through optimal design of bulb dimensions and diffuser channel shape, the hydraulic system efficiency has improved evidently. Furthermore, the structures of propeller pumps have been optimized to for the introduction of conventional as well as permanent magnet motors. In order to improve the hydraulic efficiency of pumping systems, both the pump discharge and the motor diameter were optimized respectively. If a conventional motor is used, the diameter of the pump casing has to be increased to accommodate the motor installed inside. If using a permanent magnet motor, the diameter of motor casing can be decreased effectively without decreasing its output power, thus the cross-sectional area is enlarged and the velocity of flowing water decreased favorably to reduce hydraulic loss of discharge channel and thereby raising the pumping system efficiency. Witness model tests were conducted after numerical optimization on specific propeller pump systems, indicating that the model system hydraulic efficiencies can be improved by 0.5%˜3.7% in different specified operational conditions.

Numerical study on the responses of groundwater and strata to pumping and recharge in a deep confined aquifer

NASA Astrophysics Data System (ADS)

Zhang, Yang-Qing; Wang, Jian-Hua; Chen, Jin-Jian; Li, Ming-Guang

2017-05-01

Groundwater drawdown and strata settlements induced by dewatering in confined aquifers can be relieved by artificial recharge. In this study, numerical simulations of a field multi-well pumping-recharge test in a deep confined aquifer are conducted to analyze the responses of groundwater and strata to pumping and recharge. A three-dimensional numerical model is developed in a finite-difference software, which considers the fluid-mechanical interaction using the Biot consolidation theory. The predicted groundwater drawdown and ground settlements are compared to the measured data to confirm the validation of the numerical analysis of the pumping and recharge. Both numerical results and measured data indicate that the effect of recharge on controlling the groundwater drawdown and strata settlements correlates with the injection rate and well arrangements. Since the groundwater drawdown induced by pumping can be controlled by artificial recharge, soil compression can be relieved by reducing the changes of effective stress of the soils. Consequently, strata settlement induced by pumping can be relieved by artificial recharge and ground settlements can be eliminated if an appropriate injection rate and well arrangement are being determined. Moreover, the changes of the pore pressure and seepage force induced by pumping and recharge will also result in significant horizontal deformations in the strata near the recharge wells.

Fields of application of continuous subcutaneous insulin infusion in the treatment of diabetes and implications in the use of rapid-acting insulin analogues.

PubMed

Pitocco, D; Rizzi, A; Scavone, G; Tanese, L; Zaccardi, F; Manto, A; Ghirlanda, G

2013-09-01

In western countries, diabetes mellitus, because of macrovascular and microvascular complications related to it, is still an important cause of death. Patients with type 1 diabetes mellitus (T1DM) have a six-time higher risk of mortality than healthy patients. Since the Diabetes Control and Complications Trial (DCCT) established how an intensive therapy is necessary to prevent diabetes mellitus complications, many studies have been conducted to understand which method is able to reach an optimal metabolic control. In the past 30 years continuous subcutaneous insulin infusion established/introduced as a validate alternative to multiple daily injections. Several trials demonstrated that, when compared to MDI, CSII brings to a better metabolic control, in terms of a reduction of glycated hemoglobin and blood glucose variability, hypoglycemic episodes and improvement in quality of life. Because of their pharmacokinetic and pharmacodynamic characteristics, rapid-action insulin analogues are imposed as best insulin to be used in CSII. The rapid onset and the fast reached peak make them better mimic the way how pancreas secretes insulin. CSII by pump is not free from issues. Catheter occlusions, blockages, clogs can arrest insulin administration. The consequent higher levels of glycemic values, can easily bring to the onset of ketoacidosis, with an high risk for patients' life. Aspart is a rapid analogue obtained by aminoacidic substitution. It is as effective as lispro and glulisine in gaining a good metabolic control and even better in reducing glucose variability. Some studies tried to compare rapid analogues in terms of stability. Obtained data are controversial. An in vivo study evidenced higher stability or glulisine, while studies in vitro highlighted a higher safety of aspart. Nowadays it is not possible to assess which analogues is safer. When the infusion set is changed every 48 hours equivalent rates of occlusions have been observed.

The Diabeo software enabling individualized insulin dose adjustments combined with telemedicine support improves HbA1c in poorly controlled type 1 diabetic patients: a 6-month, randomized, open-label, parallel-group, multicenter trial (TeleDiab 1 Study).

PubMed

Charpentier, Guillaume; Benhamou, Pierre-Yves; Dardari, Dured; Clergeot, Annie; Franc, Sylvia; Schaepelynck-Belicar, Pauline; Catargi, Bogdan; Melki, Vincent; Chaillous, Lucy; Farret, Anne; Bosson, Jean-Luc; Penfornis, Alfred

2011-03-01

To demonstrate that Diabeo software enabling individualized insulin dose adjustments combined with telemedicine support significantly improves HbA(1c) in poorly controlled type 1 diabetic patients. In a six-month open-label parallel-group, multicenter study, adult patients (n = 180) with type 1 diabetes (>1 year), on a basal-bolus insulin regimen (>6 months), with HbA(1c) ≥ 8%, were randomized to usual quarterly follow-up (G1), home use of a smartphone recommending insulin doses with quarterly visits (G2), or use of the smartphone with short teleconsultations every 2 weeks but no visit until point end (G3). Six-month mean HbA(1c) in G3 (8.41 ± 1.04%) was lower than in G1 (9.10 ± 1.16%; P = 0.0019). G2 displayed intermediate results (8.63 ± 1.07%). The Diabeo system gave a 0.91% (0.60; 1.21) improvement in HbA(1c) over controls and a 0.67% (0.35; 0.99) reduction when used without teleconsultation. There was no difference in the frequency of hypoglycemic episodes or in medical time spent for hospital or telephone consultations. However, patients in G1 and G2 spent nearly 5 h more than G3 patients attending hospital visits. The Diabeo system gives a substantial improvement to metabolic control in chronic, poorly controlled type 1 diabetic patients without requiring more medical time and at a lower overall cost for the patient than usual care.

Signal transduction meets vesicle traffic: the software and hardware of GLUT4 translocation.

PubMed

Klip, Amira; Sun, Yi; Chiu, Tim Ting; Foley, Kevin P

2014-05-15

Skeletal muscle is the major tissue disposing of dietary glucose, a function regulated by insulin-elicited signals that impart mobilization of GLUT4 glucose transporters to the plasma membrane. This phenomenon, also central to adipocyte biology, has been the subject of intense and productive research for decades. We focus on muscle cell studies scrutinizing insulin signals and vesicle traffic in a spatiotemporal manner. Using the analogy of an integrated circuit to approach the intersection between signal transduction and vesicle mobilization, we identify signaling relays ("software") that engage structural/mechanical elements ("hardware") to enact the rapid mobilization and incorporation of GLUT4 into the cell surface. We emphasize how insulin signal transduction switches from tyrosine through lipid and serine phosphorylation down to activation of small G proteins of the Rab and Rho families, describe key negative regulation step of Rab GTPases through the GTPase-activating protein activity of the Akt substrate of 160 kDa (AS160), and focus on the mechanical effectors engaged by Rabs 8A and 10 (the molecular motor myosin Va), and the Rho GTPase Rac1 (actin filament branching and severing through Arp2/3 and cofilin). Finally, we illustrate how actin filaments interact with myosin 1c and α-Actinin4 to promote vesicle tethering as preamble to fusion with the membrane. Copyright © 2014 the American Physiological Society.

System Description for Tank 241-AZ-101 Waste Retrieval Data Acquisition System

DOE Office of Scientific and Technical Information (OSTI.GOV)

ROMERO, S.G.

2000-01-10

Describes the hardware and software for the AZ-101 Mixer Pump Data Acquisition System. The purpose of the tank 241-AZ-101 retrieval system Data Acquisition System (DAS) is to provide monitoring and data acquisition of key parameters in order to confirm the effectiveness of the mixer pumps utilized for suspending solids in the tank. The suspension of solids in Tank 241-AZ-101 is necessary for pretreatment of the neutralized current acid waste (NCAW), and eventual disposal as glass via the Hanford Waste Vitrification Plant.

Mathematical model of glucose-insulin homeostasis in healthy rats.

PubMed

Lombarte, Mercedes; Lupo, Maela; Campetelli, German; Basualdo, Marta; Rigalli, Alfredo

2013-10-01

According to the World Health Organization there are over 220 million people in the world with diabetes and 3.4 million people died in 2004 as a consequence of this pathology. Development of an artificial pancreas would allow to restore control of blood glucose by coupling an infusion pump to a continuous glucose sensor in the blood. The design of such a device requires the development and application of mathematical models which represent the gluco-regulatory system. Models developed by other research groups describe very well the gluco-regulatory system but have a large number of mathematical equations and require complex methodologies for the estimation of its parameters. In this work we propose a mathematical model to study the homeostasis of glucose and insulin in healthy rats. The proposed model consists of three differential equations and 8 parameters that describe the variation of: blood glucose concentration, blood insulin concentration and amount of glucose in the intestine. All parameters were obtained by setting functions to the values of glucose and insulin in blood obtained after oral glucose administration. In vivo and in silico validations were performed. Additionally, a qualitative analysis has been done to verify the aforementioned model. We have shown that this model has a single, biologically consistent equilibrium point. This model is a first step in the development of a mathematical model for the type I diabetic rat. Copyright © 2013 Elsevier Inc. All rights reserved.

Banting Memorial Lecture 2014* Technology and diabetes care: appropriate and personalized.

PubMed

Pickup, J C

2015-01-01

Continuous subcutaneous insulin infusion was initially developed as a research procedure in the 1970s but quickly became a routine treatment for selected people with Type 1 diabetes. Continuous subcutaneous insulin infusion and other diabetes technologies, such as continuous glucose monitoring, are now an established and evidence-based part of diabetes care, but there has been some confusion about effectiveness and best use, particularly because of conflicting results from meta-analyses. This is because literature summary meta-analyses (including all trials) are inappropriate for therapeutic and economic decision-making; such meta-analyses should only include trials representative of groups likely to benefit. For example, for continuous subcutaneous insulin infusion, this would be those with continued disabling hypoglycaemia or elevated HbA1c levels. Alternatively, individual patient data meta-analysis allows modelling of covariates that determine effect size, e.g. in the case of continuous glucose monitoring, baseline HbA1c and frequency of sensor usage. Diabetes technology is therefore an example of personalized medicine, where evaluation and use should be both appropriate and targeted. This will also apply to future technologies such as new 'patch' pumps for Type 2 diabetes, closed-loop insulin delivery systems and nanomedicine applications in diabetes that we are currently researching. These include fluorescence lifetime-based non-invasive glucose monitoring and nanoencapsulation of islets for improved post-transplant survival. © 2014 The Author. Diabetic Medicine © 2014 Diabetes UK.

Cystic fibrosis-related diabetes in adults: where can we go from here?

PubMed

de Valk, Harold W; van der Graaf, Eduard A

2007-01-01

Cystic fibrosis (CF), a dysfunction of the exocrine glands, is one of the most frequently diagnosed genetic diseases. It is characterized by chronic pulmonary disease and pancreatic deficiency. Cystic fibrosis-related diabetes (CFRD) is a complication of CF and develops from impaired glucose tolerance via postprandial hyperglycemia with fasting normoglycemia to full-blown diabetes with fasting and postprandial hyperglycemia. CFRD is related to decreased life expectancy, most notably in female patients, as well as to decreased pulmonary function and body weight reduction, which can be improved with adequate insulin therapy. Insulin therapy is accepted in full-blown diabetes but the treatment required by lesser degrees of abnormal glucose metabolism is unknown and needs to be clarified. Chronic organ complications of diabetes are seen only in full-blown diabetes with a particular tendency to affect the autonomous nervous system. Continuous glucose measurement techniques have opened new fields of investigation, particularly in relation to CF-related complications. Insulin therapy needs to be intensified and insulin pump therapy should receive more attention. While improvements in therapy, including lung transplantation, have resulted in increased life expectancies, other issues, such as fertility problems and pregnancy, have raised new questions. All of these need to be addressed to find new treatment options for CFRD patients. In this article we aim to illustrate how these new questions in the treatment of adult patients with CFRD could be answered.

Beyond Reasonable Doubt: Who Is the Culprit in Lipotoxicity in NAFLD/NASH?

PubMed Central

Arteel, Gavin E.

2016-01-01

BACKGROUND & AIMS Type 2 diabetes and nonalcoholic steatohepatitis (NASH) are associated with insulin resistance and disordered cholesterol homeostasis. We investigated the basis for hepatic cholesterol accumulation with insulin resistance and its relevance to the pathogenesis of NASH. METHODS Alms1 mutant (foz/foz) and wild-type NOD.B10 mice were fed high-fat diets that contained varying percentages of cholesterol; hepatic lipid pools and pathways of cholesterol turnover were determined. Hepatocytes were exposed to insulin concentrations that circulate in diabetic foz/foz mice. RESULTS Hepatic cholesterol accumulation was attributed to up-regulation of low-density lipoprotein receptor via activation of sterol regulatory element binding protein 2 (SREBP-2), reduced biotransformation to bile acids, and suppression of canalicular pathways for cholesterol and bile acid excretion in bile. Exposing primary hepatocytes to concentrations of insulin that circulate in diabetic Alms1 mice replicated the increases in SREBP-2 and low-density lipoprotein receptor and suppression of bile salt export pump. Removing cholesterol from diet prevented hepatic accumulation of free cholesterol and NASH; increasing dietary cholesterol levels exacerbated hepatic accumulation of free cholesterol, hepatocyte injury or apoptosis, macrophage recruitment, and liver fibrosis. CONCLUSIONS In obese, diabetic mice, hyperinsulinemia alters nuclear transcriptional regulators of cholesterol homeostasis, leading to hepatic accumulation of free cholesterol; the resulting cytotoxicity mediates transition of steatosis to NASH. PMID:22422583

Hepatic free cholesterol accumulates in obese, diabetic mice and causes nonalcoholic steatohepatitis.

PubMed

Van Rooyen, Derrick M; Larter, Claire Z; Haigh, W Geoffrey; Yeh, Matthew M; Ioannou, George; Kuver, Rahul; Lee, Sum P; Teoh, Narci C; Farrell, Geoffrey C

2011-10-01

Type 2 diabetes and nonalcoholic steatohepatitis (NASH) are associated with insulin resistance and disordered cholesterol homeostasis. We investigated the basis for hepatic cholesterol accumulation with insulin resistance and its relevance to the pathogenesis of NASH. Alms1 mutant (foz/foz) and wild-type NOD.B10 mice were fed high-fat diets that contained varying percentages of cholesterol; hepatic lipid pools and pathways of cholesterol turnover were determined. Hepatocytes were exposed to insulin concentrations that circulate in diabetic foz/foz mice. Hepatic cholesterol accumulation was attributed to up-regulation of low-density lipoprotein receptor via activation of sterol regulatory element binding protein 2 (SREBP-2), reduced biotransformation to bile acids, and suppression of canalicular pathways for cholesterol and bile acid excretion in bile. Exposing primary hepatocytes to concentrations of insulin that circulate in diabetic Alms1 mice replicated the increases in SREBP-2 and low-density lipoprotein receptor and suppression of bile salt export pump. Removing cholesterol from diet prevented hepatic accumulation of free cholesterol and NASH; increasing dietary cholesterol levels exacerbated hepatic accumulation of free cholesterol, hepatocyte injury or apoptosis, macrophage recruitment, and liver fibrosis. In obese, diabetic mice, hyperinsulinemia alters nuclear transcriptional regulators of cholesterol homeostasis, leading to hepatic accumulation of free cholesterol; the resulting cytotoxicity mediates transition of steatosis to NASH. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

Hepatic Free Cholesterol Accumulates in Obese, Diabetic Mice and Causes Non-Alcoholic Steatohepatitis

PubMed Central

Van Rooyen, Derrick M; Larter, Claire Z; Haigh, W Geoffrey; Yeh, Matthew M; Ioannou, George; Kuver, Rahul; Lee, Sum P; Teoh, Narci C; Farrell, Geoffrey C

2011-01-01

Background & Aims Type-2 diabetes and non-alcoholic steatohepatitis (NASH) are associated with insulin resistance and disordered cholesterol homeostasis. We investigated the basis for hepatic cholesterol accumulation with insulin resistance and its relevance to pathogenesis of NASH. Methods Alms1 mutant (foz/foz) and wild-type (WT) NOD.B10 mice were fed high-fat diets that contained varying percentages of cholesterol; hepatic lipid pools and pathways of cholesterol turnover were determined. Hepatocytes were exposed to insulin concentrations that circulate in diabetic foz/foz mice. Results Hepatic cholesterol accumulation was attributed to up-regulation of low density lipoprotein receptor (LDLR) via activation of sterol regulatory element binding protein-2 (SREBP-2), reduced biotransformation to bile acids, and suppression of canalicular pathways for cholesterol and bile acid excretion in bile. Exposing primary hepatocytes to concentrations of insulin that circulate in diabetic Alms1 mice replicated the increases in SREBP-2 and LDLR and suppression of bile salt export pump. Removing cholesterol from diet prevented hepatic accumulation of free cholesterol and NASH; increasing dietary cholesterol exacerbated hepatic accumulation of free cholesterol, hepatocyte injury or apoptosis, macrophage recruitment, and liver fibrosis. Conclusions In obese, diabetic mice, hyperinsulinemia alters nuclear transcriptional regulators of cholesterol homeostasis, leading to hepatic accumulation of free cholesterol; the resulting cytotoxicity mediates transition of steatosis to NASH. PMID:21703998

Insulin delivery device technology 2012: where are we after 90 years?

PubMed

Fry, Andrew

2012-07-01

Since the first successful use of insulin in 1921 to treat diabetes at Toronto General Hospital, the major advances in development of the medication itself have taken place in parallel with equally significant developments in the means of delivery. Administration of insulin remains parenteral. This article reviews the main variants in prescription-available delivery technology: vial and syringe, pen injector, needle-free injection, and continuous subcutaneous insulin infusion pumps. For each of these, the background and major milestones are covered briefly and followed by a discussion of the latest product innovations, technologies, and implementations, which are all considered in the context of the interaction with users. The article concludes by reflecting upon how the progress in the technology of diabetes management can best serve the patient. The spectacular technological advances in medication, monitoring, and delivery since 1922 have transformed the lives of millions. However, the fact that we can add sophisticated technology to delivery devices and accessories does not mean it is always the best thing for the patient. Electronic sophistication may be welcomed by a young, eager type 1 diabetes patient, while a senior citizen who discovers he has type 2 diabetes may yearn for simplicity. Technology continues to provide great solutions, but the type of solution delivered must be matched to the user if the maximum benefit is to be achieved for all. © 2012 Diabetes Technology Society.

Insulin Delivery Device Technology 2012: Where Are We after 90 Years?

PubMed Central

Fry, Andrew

2012-01-01

Since the first successful use of insulin in 1921 to treat diabetes at Toronto General Hospital, the major advances in development of the medication itself have taken place in parallel with equally significant developments in the means of delivery. Administration of insulin remains parenteral. This article reviews the main variants in prescription-available delivery technology: vial and syringe, pen injector, needle-free injection, and continuous subcutaneous insulin infusion pumps. For each of these, the background and major milestones are covered briefly and followed by a discussion of the latest product innovations, technologies, and implementations, which are all considered in the context of the interaction with users. The article concludes by reflecting upon how the progress in the technology of diabetes management can best serve the patient. The spectacular technological advances in medication, monitoring, and delivery since 1922 have transformed the lives of millions. However, the fact that we can add sophisticated technology to delivery devices and accessories does not mean it is always the best thing for the patient. Electronic sophistication may be welcomed by a young, eager type 1 diabetes patient, while a senior citizen who discovers he has type 2 diabetes may yearn for simplicity. Technology continues to provide great solutions, but the type of solution delivered must be matched to the user if the maximum benefit is to be achieved for all. PMID:22920823

Young people with type 1 diabetes mellitus: Attitudes, perceptions, and experiences of diabetes management and continuous subcutaneous insulin infusion therapy.

PubMed

Perry, Lin; James, Steven; Steinbeck, Katharine; Dunbabin, Janet; Lowe, Julia

2017-06-01

Continuous subcutaneous insulin infusion (CSII; insulin pump) use is increasing. However, there is little information about how this technology is used compared with other insulin delivery methods (ie, injections) by young people with type 1 diabetes mellitus in Australia. This study explored young people's attitudes, perceptions, and experiences with diabetes management comparing those using with those not using CSII, and proportions likely to transition to adult services requiring initiation and/or support for CSII use. A survey was undertaken of young people (aged 12 to 18 years) with type 1 diabetes mellitus and their parents/guardians living in Hunter New England, Australia, using a questionnaire designed to collect quantitative, descriptive, and demographic data. Most questions were based on previously developed and validated instruments. In total, 107 respondents returned partially or fully completed questionnaires. Respondents had positive attitudes and perceptions of their self-efficacy and diabetes management, but were moderately disturbed by their diabetes and reported experiencing suboptimal management outcomes. Patterns of associations were demonstrated between knowledge, attitudes, and experiences of diabetes modeled by regression analysis. There were no statistically significant differences in responses between users and nonusers of CSII. Over 40% indicated their intention to use the technology as adults. Opportunities for enhanced diabetes service support were clear, and CSII did not appear to be used to its full potential. Service redesign could enhance support for this young population using all preferred insulin delivery methods and should align to patients' goals and preferences to maximize service and patient gain. © 2017 John Wiley & Sons, Ltd.

Chronic hyperinsulinemia promotes meta-inflammation and extracellular matrix deposition in adipose tissue: Implications of nitric oxide.

PubMed

Kumar, Durgesh; Shankar, Kripa; Patel, Saraswati; Gupta, Abhishek; Varshney, Salil; Gupta, Sanchita; Rajan, Sujith; Srivastava, Ankita; Vishwakarma, Achchhe Lal; Gaikwad, Anil N

2018-05-10

Various imperative studies support the notion that hyperinsulinemia (HI) itself serves as the common link between adipose tissue inflammation (ATI) and metabolic syndrome. However, the contribution of HI mediated ATI and its metabolic consequences are yet to be explored. We induced chronic HI per se in mice by administration of exogenous insulin for 8 weeks through mini-osmotic pumps. For the reduction of circulating insulin in response to excess calorie intake, we have partially ablated β-cells by using streptozotocin (STZ) in the diet-induced obesity (DIO) and genetic mice models (db/db). Flow cytometry analysis was performed for the quantification of immune cells in stromal vascular fraction (SVF) isolated from epididymal white adipose tissue (eWAT). Our studies demonstrated that chronic HI augmented ATI in terms of elevated pro-inflammatory cells (M1 macrophages and NK-cells) and suppressed anti-inflammatory cells (M2 macrophages, eosinophils and regulatory T-cells). These results were correlated with altered obesity-associated metabolic phenotype. Partial reduction of circulating insulin level attenuated excess calorie-induced ATI and improved insulin sensitivity. Mechanistically, an imbalance in M1 and M2 macrophage proportions in eWAT promoted iNOS (inducible nitric oxide synthase): arginase-1 imbalance that resulted into extracellular matrix (ECM) deposition and insulin resistance (IR) development. However, iNOS -/- mice were protected from HI-induced M1:M2 macrophage imbalance, ECM deposition and IR in adipose tissue. Overall, we conclude that chronic HI per se contributed in ATI and iNOS corroborated ECM deposition. Copyright © 2018. Published by Elsevier B.V.

Types and Frequency of Infusion Pump Alarms: Protocol for a Retrospective Data Analysis.

PubMed

Glover, Kevin R; Vitoux, Rachel R; Schuster, Catherine; Curtin, Christopher R

2018-06-14

The variety of alarms from all types of medical devices has increased from 6 to 40 in the last three decades, with today's most critically ill patients experiencing as many as 45 alarms per hour. Alarm fatigue has been identified as a critical safety issue for clinical staff that can lead to potentially dangerous delays or nonresponse to actionable alarms, resulting in serious patient injury and death. To date, most research on medical device alarms has focused on the nonactionable alarms of physiological monitoring devices. While there have been some reports in the literature related to drug library alerts during the infusion pump programing sequence, research related to the types and frequencies of actionable infusion pump alarms remains largely unexplored. The objectives of this study protocol are to establish baseline data related to the types and frequency of infusion pump alarms from the B. Braun Outlook 400ES Safety Infusion System with the accompanying DoseTrac Infusion Management Software. The most recent consecutive 60-day period of backup hospital data received between April 2014 and February 2017 from 32 United States-based hospitals will be selected for analysis. Microsoft SQL Server (2012 - 11.0.5343.0 X64) will be used to manage the data with unique code written to sort data and perform descriptive analyses. A validated data management methodology will be utilized to clean and analyze the data. Data management procedures will include blinding, cleaning, and review of existing infusion data within the DoseTrac Infusion Management Software databases at each hospital. Patient-identifying data will be removed prior to merging into a dedicated and secure data repository. This pooled data will then be analyzed. This exploratory study will analyze the aggregate alarm data for each hospital by care area, drug infused, time of day, and day of week, including: overall infusion pump alarm frequency (number of alarms per active infusion), duration of alarms (average, range, median), and type and frequency of alarms distributed by care area. Infusion pump alarm data collected and analyzed in this study will be used to help establish a baseline of infusion pump alarm types and relative frequencies. Understanding the incidences and characteristics of infusion pump alarms will result in more informed quality improvement recommendations to decrease and/or modify infusion pump alarms, and potentially reduce clinical staff alarm fatigue and improve patient safety. . RR1-10.2196/10446. ©Kevin R Glover, Rachel R Vitoux, Catherine Schuster, Christopher R Curtin. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 14.06.2018.

Thermal Analysis of Magnetically-Coupled Pump for Cryogenic Applications

NASA Technical Reports Server (NTRS)

Senocak, Inanc; Udaykumar, H. S.; Ndri, Narcisse; Francois, Marianne; Shyy, Wei

1999-01-01

Magnetically-coupled pump is under evaluation at Kennedy Space Center for possible cryogenic applications. A major concern is the impact of low temperature fluid flows on the pump performance. As a first step toward addressing this and related issues, a computational fluid dynamics and heat transfer tool has been adopted in a pump geometry. The computational tool includes (i) a commercial grid generator to handle multiple grid blocks and complicated geometric definitions, and (ii) an in-house computational fluid dynamics and heat transfer software developed in the Principal Investigator's group at the University of Florida. Both pure-conduction and combined convection-conduction computations have been conducted. A pure-conduction analysis gives insufficient information about the overall thermal distribution. Combined convection-conduction analysis indicates the significant influence of the coolant over the entire flow path. Since 2-D simulation is of limited help, future work on full 3-D modeling of the pump using multi-materials is needed. A comprehensive and accurate model can be developed to take into account the effect of multi-phase flow in the cooling flow loop, and the magnetic interactions.

Hybrid Geothermal Heat Pumps for Cooling Telecommunications Data Centers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beckers, Koenraad J; Zurmuhl, David P.; Lukawski, Maciej Z.

The technical and economic performance of geothermal heat pump (GHP) systems supplying year-round cooling to representative small data centers with cooling loads less than 500 kWth were analyzed and compared to air-source heat pumps (ASHPs). A numerical model was developed in TRNSYS software to simulate the operation of air-source and geothermal heat pumps with and without supplementary air cooled heat exchangers - dry coolers (DCs). The model was validated using data measured at an experimental geothermal system installed in Ithaca, NY, USA. The coefficient of performance (COP) and cooling capacity of the GHPs were calculated over a 20-year lifetime andmore » compared to the performance of ASHPs. The total cost of ownership (TCO) of each of the cooling systems was calculated to assess its economic performance. Both the length of the geothermal borehole heat exchangers (BHEs) and the dry cooler temperature set point were optimized to minimize the TCO of the geothermal systems. Lastly, a preliminary analysis of the performance of geothermal heat pumps for cooling dominated systems was performed for other locations including Dallas, TX, Sacramento, CA, and Minneapolis, MN.« less

Effect of Pumping on Groundwater Levels: A Case Study

NASA Astrophysics Data System (ADS)

Sindhu, G.; Vijayachandran, Lekshmi

2018-03-01

Groundwater is a major source for drinking and domestic purposes. Nowadays, extensive pumping has become a major issue of concern since pumping has led to rapid decline in the groundwater table, thus imposing landward gradient, leading to saline water intrusion especially in coastal areas. Groundwater pumping has seen its utmost effect on coastal aquifer systems, where the sea-ward gradient gets disturbed due to anthropogenic influences. Hence, a groundwater flow modelling of an aquifer system is essential for understanding the various hydro-geologic conditions, which can be used to study the responses of the aquifer system with regard to various pumping scenarios. Besides, a model helps to predict the water levels for the future period with respect to changing environment. In this study, a finite element groundwater flow model of a coastal aquifer system at Aakulam, Trivandrum district is developed, calibrated and simulated using the software Finite Element subsurface Flow system (FEFLOW 6.2).This simulated model is then used to predict the groundwater levels for a future 5 year period during pre monsoon and post monsoon season.

Effect of Pumping on Groundwater Levels: A Case Study

NASA Astrophysics Data System (ADS)

Sindhu, G.; Vijayachandran, Lekshmi

2018-06-01

Groundwater is a major source for drinking and domestic purposes. Nowadays, extensive pumping has become a major issue of concern since pumping has led to rapid decline in the groundwater table, thus imposing landward gradient, leading to saline water intrusion especially in coastal areas. Groundwater pumping has seen its utmost effect on coastal aquifer systems, where the sea-ward gradient gets disturbed due to anthropogenic influences. Hence, a groundwater flow modelling of an aquifer system is essential for understanding the various hydro-geologic conditions, which can be used to study the responses of the aquifer system with regard to various pumping scenarios. Besides, a model helps to predict the water levels for the future period with respect to changing environment. In this study, a finite element groundwater flow model of a coastal aquifer system at Aakulam, Trivandrum district is developed, calibrated and simulated using the software Finite Element subsurface Flow system (FEFLOW 6.2).This simulated model is then used to predict the groundwater levels for a future 5 year period during pre monsoon and post monsoon season.

Diabetes and Ramadan: A concise and practical update

PubMed Central

Ahmed, Mohamed H.; Husain, Nazik Elmalaika; Elmadhoun, Wadie M.; Noor, Sufian K.; Khalil, Abbas A.; Almobarak, Ahmed O.

2017-01-01

Despite the fact that the month of Ramadan includes 29–30 days and the duration of fasting for each day can last for between 12 and 16 h, it was estimated that a large number of individuals with diabetes do fast during Ramadan. In light of recent advancement of new pharmacological agents, drugs such as vildagliptin, sitagliptin, and liraglutide were found to be safe to use during this month of fasting. These therapeutic agents can also be used in combination with metformin. The use of sulfonylureas, in most of the recent guidelines about diabetes and Ramadan, seems not to gain much support due to the risk of hypoglycemia. In this review, we also addressed the use of insulin injection, insulin pump, and education before, during, and after Ramadan. Further research is needed to determine (i) the therapeutic benefit of new antidiabetic agents and (ii) the benefit of new technologies for the treatment of diabetes. PMID:29026740

Numerical investigation of the effect of number of blades on centrifugal pump performance

NASA Astrophysics Data System (ADS)

Kocaaslan, O.; Ozgoren, M.; Babayigit, O.; Aksoy, M. H.

2017-07-01

In this study, the flow structure in a centrifugal pump was numerically investigated for the different blade numbers in the impeller between 5 and 9. The pump used in the study is a single-stage horizontal shafted centrifugal pump. The original pump impeller was designed as 7 blades for the parameters of flow rate Q=100 mł/h, head Hm=180 kPa and revolution n=1480 rpm. First, models of impellers with the different blade numbers between 5 and 9 and the volute section of the centrifugal pump were separately drawn using Solidworks software. Later, grid structures were generated on the flow volume of the pump. Last, the flow analyses were performed and the flow characteristics under different operational conditions were determined numerically. In the numerical analyses, k-ɛ turbulence model and standard wall functions were used to solve turbulent flow. Balance holes and surface roughness, which adversely affect the hydraulic efficiency of pumps, were also considered. The obtained results of the analyses show that the hydraulic torque and head values have increased with the application of higher number of the impeller blades. For the impellers with 5 and 9 blades on the design flow rate of 100 mł/h (Q/Qd=1), the hydraulic torque and head were found 49/59.1 Nm and 153.1/184.4 kPa, respectively. Subsequently the hydraulic efficiencies of each pump were calculated. As a result, the highest hydraulic efficiency on the design flow rate was calculated as 54.16% for the pump impeller having 8 blades.

Using Smart Pumps to Understand and Evaluate Clinician Practice Patterns to Ensure Patient Safety

PubMed Central

Mansfield, Jennifer; Jarrett, Steven

2013-01-01

Background: Safety software installed on intravenous (IV) infusion pumps has been shown to positively impact the quality of patient care through avoidance of medication errors. The data derived from the use of smart pumps are often overlooked, although these data provide helpful insight into the delivery of quality patient care. Objective: The objectives of this report are to describe the value of implementing IV infusion safety software and analyzing the data and reports generated by this system. Case study: Based on experience at the Carolinas HealthCare System (CHS), executive score cards provide an aggregate view of compliance rate, number of alerts, overrides, and edits. The report of serious errors averted (ie, critical catches) supplies the location, date, and time of the critical catch, thereby enabling management to pinpoint the end-user for educational purposes. By examining the number of critical catches, a return on investment may be calculated. Assuming 3,328 of these events each year, an estimated cost avoidance would be $29,120,000 per year for CHS. Other reports allow benchmarking between institutions. Conclusion: A review of the data about medication safety across CHS has helped garner support for a medication safety officer position with the goal of ultimately creating a safer environment for the patient. PMID:24474836

Myocardial protection by glucose-insulin-potassium in acute coronary syndrome patients undergoing urgent multivessel off-pump coronary artery bypass surgery.

PubMed

Shim, J-K; Yang, S-Y; Yoo, Y-C; Yoo, K-J; Kwak, Y-L

2013-01-01

The aim of this randomized and controlled trial was to investigate the effect of a glucose-insulin-potassium (GIK) solution on myocardial protection in acute coronary syndrome (ACS) patients undergoing urgent multivessel off-pump coronary artery bypass (OPCAB) surgery. Sixty-six patients were randomly allocated either to receive 0.3 ml kg(-1) h(-2) GIK solution (potassium 80 mEq and regular insulin 325 IU in 500 ml of 50% glucose) or equivalent volume of normal saline (control) upon anaesthetic induction until 6 h after reperfusion. The primary endpoints were to compare the concentrations of creatine kinase-MB (CK-MB) and troponin-T between the groups after reperfusion. The secondary endpoints were to compare the incidences of postoperative troponin-T >0.8 ng ml(-1) and myocardial infarction (MI) between the groups. Highest CK-MB [8.7 (4.4) vs 13.1 (7.9) ng ml(-1), P=0.006] and troponin-T [0.20 (0.13-0.49) vs 0.48 (0.18-0.91) ng ml(-1), P<0.0001] values after reperfusion were significantly lower in the GIK group compared with the control group. The area under the curve of serially measured troponin-T was also significantly smaller in the GIK group compared with the control group [0.83 (0.43-1.81) vs 0.46 (0.31-1.00), P=0.036]. Significantly fewer patients in the GIK group showed troponin-T >0.8 ng ml(-1) after reperfusion compared with the control group (3 vs 11, P=0.033). The incidence of postoperative MI was similar between the groups. GIK administration in ACS patients undergoing urgent multivessel OPCAB significantly attenuated the degree of ensuing myocardial injury without complications related to glycaemic control. Clinical Trial Registry. URL: http://clinicaltrials.gov/ct2/show/NCT01384656?term=GIK+AND+OPCAB&rank=1. Unique identification number NCT01384656.

Long-Term Efficacy and Safety of Sensor Augmented Insulin Pump Therapy with Low-Glucose Suspend Feature in Patients with Type 1 Diabetes.

PubMed

Gómez, Ana María; Marín Carrillo, Lisseth Fernanda; Muñoz Velandia, Oscar Mauricio; Rondón Sepúlveda, Martín Alonso; Arévalo Correa, Carol M; Mora Garzón, Edwin; Cuervo Diaz, Maria Camila; Henao Carrillo, Diana Cristina

2017-02-01

Literature supports short-term efficacy and safety of Sensor Augmented Insulin Pump (SAP) therapy in patients with type 1 diabetes (T1D). However, no data are available showing long-term outcomes. Our study describes the long-term outcomes of SAP therapy with low-glucose suspend feature (SAP+LGS) in hypoglycemia in a Colombian population with T1D and hypoglycemia. A cohort study was conducted with T1D patients receiving SAP+LGS therapy who initiated this therapy because of hypoglycemia at San Ignacio University Hospital diabetes center in Bogotá, Colombia. Glycated hemoglobin (A1c) was assessed at least every 6 months, severe hypoglycemia (SH) and hypoglycemia unawareness (HU) incidence yearly. Adherence to therapy was also evaluated. One hundred eleven patients were included in the analysis. Total daily insulin dose was reduced during follow-up (mean difference -0.22 U/kg; 95% confidence interval [CI] -0.18 to -0.26; P < 0.001). A1c levels were reduced from a baseline value of 8.8% ± 1.9% to 7.5% ± 1.0% at 5 months (mean difference -1.3%; 95% CI -1.09 to -1.50; P < 0.001) and 7.1% ± 0.8% (mean difference -1.7%; 95% CI -1.59 to -1.90; P < 0.001) at the end of follow-up (47 months on average). The incidence of SH and HU episodes decreased significantly since the first year, and this effect was maintained over time (P < 0.001). SAP+LGS therapy in T1D patients with hypoglycemia led to a significant and sustained decrease in A1c during long periods of follow-up, as well as a significant reduction in SH and HU. Future randomized clinical trials are desired.

Evaluation of Intradermal and Subcutaneous Infusion Set Performance Under 24-Hour Basal and Bolus Conditions

PubMed Central

McVey, Elaine; Keith, Steven; Herr, Joshua K.; Sutter, Diane; Pettis, Ronald J.

2015-01-01

Background: This study sought to assess the function and delivery reliability of intradermal (ID) infusion sets used with commercial insulin pumps. Method: Healthy subjects (n = 43) were randomized to either ID or subcutaneous (SC) arms, and received basal/bolus placebo delivery for 24 hours. Subjects received 4 of 8 infusion set combinations (ID: microneedle design A or B, with 2 pump brands [Animas or MiniMed]; SC: Teflon Quickset or steel Rapid-D, Animas pump only, with or without overtaping) and were evaluated for pump occlusion alarms, fluid leakage, pain, and tissue tolerability. A novel algorithm was developed to determine flow consistency based on fluid pressure, and the duration and occurrence rate for periods of unalarmed but interrupted flow (“silent occlusions’”) were compared. Results: ID delivery was successfully maintained over the 24-hour infusion period. The number of silent occlusions was lower for ID microneedle cannula design B than A (P < .01) and lower for Rapid-D SC device compared to Quick-set (P = .03). There was no significant difference in the number of occlusion alarms between the ID and SC devices with the Animas pump. However, the pumps tested with ID devices had significantly different alarm rates (MiniMed 29.5%, Animas 0%, P < .001). Leakage and tissue tolerability were comparable across devices. Conclusion: The ID infusion set reliably delivered diluent for an extended 24-hour period in healthy subjects and was well tolerated. Silent occlusion flow interruptions could be detected in both ID and SC infusion sets using a proprietary algorithm. This algorithm is a promising method for quantitatively evaluating infusion set flow performance. PMID:26319228

Severe hypoglycaemia in type 1 diabetes mellitus: underlying drivers and potential strategies for successful prevention.

PubMed

Little, S A; Leelarathna, L; Barendse, S M; Walkinshaw, E; Tan, H K; Lubina Solomon, A; de Zoysa, N; Rogers, H; Choudhary, P; Amiel, S A; Heller, S R; Evans, M; Flanagan, D; Speight, J; Shaw, J A M

2014-03-01

Hypoglycaemia remains an over-riding factor limiting optimal glycaemic control in type 1 diabetes. Severe hypoglycaemia is prevalent in almost half of those with long-duration diabetes and is one of the most feared diabetes-related complications. In this review, we present an overview of the increasing body of literature seeking to elucidate the underlying pathophysiology of severe hypoglycaemia and the limited evidence behind the strategies employed to prevent episodes. Drivers of severe hypoglycaemia including impaired counter-regulation, hypoglycaemia-associated autonomic failure, psychosocial and behavioural factors and neuroimaging correlates are discussed. Treatment strategies encompassing structured education, insulin analogue regimens, continuous subcutaneous insulin infusion pumps, continuous glucose sensing and beta-cell replacement therapies have been employed, yet there is little randomized controlled trial evidence demonstrating effectiveness of new technologies in reducing severe hypoglycaemia. Optimally designed interventional trials evaluating these existing technologies and using modern methods of teaching patients flexible insulin use within structured education programmes with the specific goal of preventing severe hypoglycaemia are required. Individuals at high risk need to be monitored with meticulous collection of data on awareness, as well as frequency and severity of all hypoglycaemic episodes. Copyright © 2013 John Wiley & Sons, Ltd.

Toward Automation of Insulin Delivery - Management Solutions for Type 1 Diabetes.

PubMed

Nimri, Revital; Phillip, Moshe

2016-01-01

In the past decade, the field of type 1 diabetes was characterized by the efforts to integrate technology into the daily management of diabetes. Automated insulin delivery systems have emerged followed by the improvements in technology of pumps and sensors and automated close-loop systems that were developed around the world for overnight as well as for day and night use. Initially, these closed-loop systems were tested clinically in research centers, then at diabetes camps or hotels, and recently at patients' homes. The systems were tested in a wide range of populations of patients with type 1 diabetes: children, adolescents, adults, newly diagnosed, well and suboptimally controlled patients, the critically ill and pregnant women. The extensive clinical evaluation found these close-loop systems to be safe and efficient in controlling blood glucose levels. Now is the time to take these systems from research to industry and to get a regulatory approval of convenient devices for the use at home. Automated insulin delivery systems have the potential to change the way diabetes is treated and managed for the benefit of patients. This chapter summarizes the recent advances in this field. © 2016 S. Karger AG, Basel.

Evaluation of PD/PID controller for insulin control on blood glucose regulation in a Type-I diabetes

NASA Astrophysics Data System (ADS)

Mahmud, Farhanahani; Isse, Nadir Hussien; Daud, Nur Atikah Mohd; Morsin, Marlia

2017-01-01

This project introduces a simulation of Proportional-Derivative (PD) and Proportional-Integral-Derivative (PID) controller based on a virtual Type 1 Diabetes Mellitus (T1DM) patient: Hovorka diabetic model using MATLAB-Simulink software. The results of these simulations are based on three tuning responses for each controller which are fast, slow and oscillation responses. The main purpose of this simulation is to achieve an acceptable stability and fastness response towards the regulation of glucose concentration using PD and PID controller response with insulin infusion rate. Therefore, in order to analyze and compare the responses of both controller performances, one-day simulations of the insulin-glucose dynamic have been conducted using a typical day meal plan that contains five meals of different bolus size. It is found that the PID closed-loop control with a short rise time is required to retrieve a satisfactory glucose regulation.

Off-pump versus on-pump coronary artery bypass surgery: meta-analysis and meta-regression of 13,524 patients from randomized trials.

PubMed

Sá, Michel Pompeu Barros de Oliveira; Ferraz, Paulo Ernando; Escobar, Rodrigo Renda; Martins, Wendell Nunes; Lustosa, Pablo César; Nunes, Eliobas de Oliveira; Vasconcelos, Frederico Pires; Lima, Ricardo Carvalho

2012-12-01

Most recent published meta-analysis of randomized controlled trials (RCTs) showed that off-pump coronary artery bypass graft surgery (CABG) reduces incidence of stroke by 30% compared with on-pump CABG, but showed no difference in other outcomes. New RCTs were published, indicating need of new meta-analysis to investigate pooled results adding these further studies. MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, LILACS, Google Scholar and reference lists of relevant articles were searched for RCTs that compared outcomes (30-day mortality for all-cause, myocardial infarction or stroke) between off-pump versus on-pump CABG until May 2012. The principal summary measures were relative risk (RR) with 95% Confidence Interval (CI) and P values (considered statistically significant when <0.05). The RR's were combined across studies using DerSimonian-Laird random effects weighted model. Meta-analysis and meta-regression were completed using the software Comprehensive Meta-Analysis version 2 (Biostat Inc., Englewood, New Jersey, USA). Forty-seven RCTs were identified and included 13,524 patients (6,758 for off-pump and 6,766 for on-pump CABG). There was no significant difference between off-pump and on-pump CABG groups in RR for 30-day mortality or myocardial infarction, but there was difference about stroke in favor to off-pump CABG (RR 0.793, 95% CI 0.660-0.920, P=0.049). It was observed no important heterogeneity of effects about any outcome, but it was observed publication bias about outcome "stroke". Meta-regression did not demonstrate influence of female gender, number of grafts or age in outcomes. Off-pump CABG reduces the incidence of post-operative stroke by 20.7% and has no substantial effect on mortality or myocardial infarction in comparison to on-pump CABG. Patient gender, number of grafts performed and age do not seem to explain the effect of off-pump CABG on mortality, myocardial infarction or stroke, respectively.

Effect of Bearing Housings on Centrifugal Pump Rotor Dynamics

NASA Astrophysics Data System (ADS)

Yashchenko, A. S.; Rudenko, A. A.; Simonovskiy, V. I.; Kozlov, O. M.

2017-08-01

The article deals with the effect of a bearing housing on rotor dynamics of a barrel casing centrifugal boiler feed pump rotor. The calculation of the rotor model including the bearing housing has been performed by the method of initial parameters. The calculation of a rotor solid model including the bearing housing has been performed by the finite element method. Results of both calculations highlight the need to add bearing housings into dynamic analyses of the pump rotor. The calculation performed by modern software packages is more a time-taking process, at the same time it is a preferred one due to a graphic editor that is employed for creating a numerical model. When it is necessary to view many variants of design parameters, programs for beam modeling should be used.

Numerical simulation and optimization of casting process for complex pump

NASA Astrophysics Data System (ADS)

Liu, Xueqin; Dong, Anping; Wang, Donghong; Lu, Yanling; Zhu, Guoliang

2017-09-01

The complex shape of the casting pump body has large complicated structure and uniform wall thickness, which easy give rise to casting defects. The numerical simulation software ProCAST is used to simulate the initial top gating process, after analysis of the material and structure characteristics of the high-pressure pump. The filling process was overall smooth, not there the water shortage phenomenon. But the circular shrinkage defects appear at the bottom of casting during solidification process. Then, the casting parameters were optimized and adding cold iron in the bottom. The shrinkage weight was reduced from 0.00167g to 0.0005g. The porosity volume was reduced from 1.39cm3 to 0.41cm3. The optimization scheme is simulated and actual experimented. The defect has been significantly improved.

Home use of a bihormonal bionic pancreas versus insulin pump therapy in adults with type 1 diabetes: a multicentre randomised crossover trial

PubMed Central

El-Khatib, Firas H; Balliro, Courtney; Hillard, Mallory A; Magyar, Kendra L; Ekhlaspour, Laya; Sinha, Manasi; Mondesir, Debbie; Esmaeili, Aryan; Hartigan, Celia; Thompson, Michael J; Malkani, Samir; Lock, J Paul; Harlan, David M; Clinton, Paula; Frank, Eliana; Wilson, Darrell M; DeSalvo, Daniel; Norlander, Lisa; Ly, Trang; Buckingham, Bruce A; Diner, Jamie; Dezube, Milana; Young, Laura A; Goley, April; Kirkman, M Sue; Buse, John B; Zheng, Hui; Selagamsetty, Rajendranath R; Damiano, Edward R; Russell, Steven J

2017-01-01

Summary Background The safety and effectiveness of a continuous, day-and-night automated glycaemic control system using insulin and glucagon has not been shown in a free-living, home-use setting. We aimed to assess whether bihormonal bionic pancreas initialised only with body mass can safely reduce mean glycaemia and hypoglycaemia in adults with type 1 diabetes who were living at home and participating in their normal daily routines without restrictions on diet or physical activity. Methods We did a random-order crossover study in volunteers at least 18 years old who had type 1 diabetes and lived within a 30 min drive of four sites in the USA. Participants were randomly assigned (1:1) in blocks of two using sequentially numbered sealed envelopes to glycaemic regulation with a bihormonal bionic pancreas or usual care (conventional or sensor-augmented insulin pump therapy) first, followed by the opposite intervention. Both study periods were 11 days in length, during which time participants continued all normal activities, including athletics and driving. The bionic pancreas was initialised with only the participant’s body mass. Autonomously adaptive dosing algorithms used data from a continuous glucose monitor to control subcutaneous delivery of insulin and glucagon. The coprimary outcomes were the mean glucose concentration and time with continuous glucose monitoring (CGM) glucose concentration less than 3·3 mmol/L, analysed over days 2–11 in participants who completed both periods of the study. This trial is registered with ClinicalTrials.gov, number NCT02092220. Findings We randomly assigned 43 participants between May 6, 2014, and July 3, 2015, 39 of whom completed the study: 20 who were assigned to bionic pancreas first and 19 who were assigned to the comparator first. The mean CGM glucose concentration was 7·8 mmol/L (SD 0·6) in the bionic pancreas period versus 9·0 mmol/L (1·6) in the comparator period (difference 1·1 mmol/L, 95% CI 0·7–1·6; p<0·0001), and the mean time with CGM glucose concentration less than 3·3 mmol/L was 0·6% (0·6) in the bionic pancreas period versus 1·9% (1·7) in the comparator period (difference 1·3%, 95% CI 0·8–1·8; p<0·0001). The mean nausea score on the Visual Analogue Scale (score 0–10) was greater during the bionic pancreas period (0·52 [SD 0·83]) than in the comparator period (0·05 [0·17]; difference 0·47, 95% CI 0·21–0·73; p=0·0024). Body mass and laboratory parameters did not differ between periods. There were no serious or unexpected adverse events in the bionic pancreas period of the study. Interpretation Relative to conventional and sensor-augmented insulin pump therapy, the bihormonal bionic pancreas, initialised only with participant weight, was able to achieve superior glycaemic regulation without the need for carbohydrate counting. Larger and longer studies are needed to establish the long-term benefits and risks of automated glycaemic management with a bihormonal bionic pancreas. Funding National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health, and National Center for Advancing Translational Sciences. PMID:28007348

Home use of a bihormonal bionic pancreas versus insulin pump therapy in adults with type 1 diabetes: a multicentre randomised crossover trial.

PubMed

El-Khatib, Firas H; Balliro, Courtney; Hillard, Mallory A; Magyar, Kendra L; Ekhlaspour, Laya; Sinha, Manasi; Mondesir, Debbie; Esmaeili, Aryan; Hartigan, Celia; Thompson, Michael J; Malkani, Samir; Lock, J Paul; Harlan, David M; Clinton, Paula; Frank, Eliana; Wilson, Darrell M; DeSalvo, Daniel; Norlander, Lisa; Ly, Trang; Buckingham, Bruce A; Diner, Jamie; Dezube, Milana; Young, Laura A; Goley, April; Kirkman, M Sue; Buse, John B; Zheng, Hui; Selagamsetty, Rajendranath R; Damiano, Edward R; Russell, Steven J

2017-01-28

The safety and effectiveness of a continuous, day-and-night automated glycaemic control system using insulin and glucagon has not been shown in a free-living, home-use setting. We aimed to assess whether bihormonal bionic pancreas initialised only with body mass can safely reduce mean glycaemia and hypoglycaemia in adults with type 1 diabetes who were living at home and participating in their normal daily routines without restrictions on diet or physical activity. We did a random-order crossover study in volunteers at least 18 years old who had type 1 diabetes and lived within a 30 min drive of four sites in the USA. Participants were randomly assigned (1:1) in blocks of two using sequentially numbered sealed envelopes to glycaemic regulation with a bihormonal bionic pancreas or usual care (conventional or sensor-augmented insulin pump therapy) first, followed by the opposite intervention. Both study periods were 11 days in length, during which time participants continued all normal activities, including athletics and driving. The bionic pancreas was initialised with only the participant's body mass. Autonomously adaptive dosing algorithms used data from a continuous glucose monitor to control subcutaneous delivery of insulin and glucagon. The coprimary outcomes were the mean glucose concentration and time with continuous glucose monitoring (CGM) glucose concentration less than 3·3 mmol/L, analysed over days 2-11 in participants who completed both periods of the study. This trial is registered with ClinicalTrials.gov, number NCT02092220. We randomly assigned 43 participants between May 6, 2014, and July 3, 2015, 39 of whom completed the study: 20 who were assigned to bionic pancreas first and 19 who were assigned to the comparator first. The mean CGM glucose concentration was 7·8 mmol/L (SD 0·6) in the bionic pancreas period versus 9·0 mmol/L (1·6) in the comparator period (difference 1·1 mmol/L, 95% CI 0·7-1·6; p<0·0001), and the mean time with CGM glucose concentration less than 3·3 mmol/L was 0·6% (0·6) in the bionic pancreas period versus 1·9% (1·7) in the comparator period (difference 1·3%, 95% CI 0·8-1·8; p<0·0001). The mean nausea score on the Visual Analogue Scale (score 0-10) was greater during the bionic pancreas period (0·52 [SD 0·83]) than in the comparator period (0·05 [0·17]; difference 0·47, 95% CI 0·21-0·73; p=0·0024). Body mass and laboratory parameters did not differ between periods. There were no serious or unexpected adverse events in the bionic pancreas period of the study. Relative to conventional and sensor-augmented insulin pump therapy, the bihormonal bionic pancreas, initialised only with participant weight, was able to achieve superior glycaemic regulation without the need for carbohydrate counting. Larger and longer studies are needed to establish the long-term benefits and risks of automated glycaemic management with a bihormonal bionic pancreas. National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health, and National Center for Advancing Translational Sciences. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of medical electronic devices in the APL space department

NASA Technical Reports Server (NTRS)

Newman, A. L.

1985-01-01

Several electronic devices for automatically correcting specific defects in a body's physiologic regulation and allowing approximately normal functioning are described. A self-injurious behavior inhibiting system (SIBIS) is fastened to the arm of a person with chronic self-injurious behavior patterns. An electric shock is delivered into the arm whenever the device senses above-threshold acceleration of the head such as occur with head-bangers. Sounding a buzzer tone with the shock eventually allows transference of the aversive stimulus to the buzzer so shocks are no longer necessary. A programmable implantable medication system features a solenoid pump placed beneath the skin and refueled by hypodermic needle. The pump functions are programmable and can deliver insulin, chemotherapy mixes and/or pain killers according to a preset schedule or on patient demand. Finally, an automatic implantible defibrillator has four electrodes attached directly to the heart for sensing electrical impulses or emitting them in response to cardiac fibrillation.

Subcutaneous glucagon infusion and continuous glucose monitoring enable effective management of hypoglycemia in a patient with IGF-2-producing hemangiopericytoma.

PubMed

Buras, Eric D; Weatherup, Emily; Wyckoff, Jennifer

2018-01-01

Ectopic insulin-like growth factor (IGF)-2 production is a rare complication of an array of epithelial and mesenchymal tumors, and can clinically manifest as life-threatening hypoglycemia. A 49-year-old woman with 13-year history of metastatic hemangiopericytoma, previously treated with multiple rounds of chemotherapy and palliative radiation, presented to the emergency department after a hypoglycemic seizure. On arrival, glucose was 18 mg/dL (1.0 mmol/L) and required continuous dextrose infusion for maintenance within normal limits. Insulin was <2.0 μU/mL, C-peptide 0.1 ng/mL, and beta-hydroxybutyrate <0.2 mmol/L. Random cortisol was 21 μg/dL; sulfonylurea screen, and insulin antibodies were negative. IGF-2 level was 1320 ng/mL; IGF-1 was within normal limits and IGF binding protein (BP)-3 suppressed. Dexamethasone, started at 6 mg twice daily, allowed discontinuation of the glucose infusion. Given concern for nocturnal hypoglycemia, and patient interest in steroid-sparing anti-hypoglycemic regimen, she was also started on overnight continuous subcutaneous glucagon infusion via insulin pump. She was discharged with instructions to maintain a diet high in complex carbohydrates during the day, while utilizing glucagon pump at night. She was also started on continuous glucose monitoring system (CGMS) with an alarm to warn of hypoglycemia. Glucagon infusion rate was later titrated based on CGMS readings. Abdominal CT revealed increasing size of a right upper quadrant mass not previously subjected to radiotherapy. After radiation to this area, hypoglycemia improved, allowing further glucagon titration. In parallel, IGF-2 level declined to 380 ng/mL. Ectopic IGF-2 production is a rare but often fatal complication of many cancers, and should be considered on the differential diagnosis in patients with malignancy and unexplained hypoglycemia. Once hypoglycemia is diagnosed, patients often have end-stage disease. While treatment of the causative tumor is the only definitive intervention, anti-hypoglycemia therapy is a life-saving, temporizing measure. In this case, the patient attained euglycemia and survived 3 months after presentation before ultimately succumbing to other malignancy-related complications. Given efficacy in management of hypoglycemia while awaiting definitive tumor-directed therapy, we submit nighttime subcutaneous glucagon infusion and CGMS are valuable additions to the physician's armamentarium in managing this condition.

The use and efficacy of continuous glucose monitoring in type 1 diabetes treated with insulin pump therapy: a randomised controlled trial.

PubMed

Battelino, T; Conget, I; Olsen, B; Schütz-Fuhrmann, I; Hommel, E; Hoogma, R; Schierloh, U; Sulli, N; Bolinder, J

2012-12-01

The aim of this multicentre, randomised, controlled crossover study was to determine the efficacy of adding continuous glucose monitoring (CGM) to insulin pump therapy (CSII) in type 1 diabetes. Children and adults (n = 153) on CSII with HbA(1c) 7.5-9.5% (58.5-80.3 mmol/mol) were randomised to (CGM) a Sensor On or Sensor Off arm for 6 months. After 4 months' washout, participants crossed over to the other arm for 6 months. Paediatric and adult participants were separately electronically randomised through the case report form according to a predefined randomisation sequence in eight secondary and tertiary centres. The primary outcome was the difference in HbA(1c) levels between arms after 6 months. Seventy-seven participants were randomised to the On/Off sequence and 76 to the Off/On sequence; all were included in the primary analysis. The mean difference in HbA(1c) was -0.43% (-4.74 mmol/mol) in favour of the Sensor On arm (8.04% [64.34 mmol/mol] vs 8.47% [69.08 mmol/mol]; 95% CI -0.32%, -0.55% [-3.50, -6.01 mmol/mol]; p < 0.001). Following cessation of glucose sensing, HbA(1c) reverted to baseline levels. Less time was spent with sensor glucose <3.9 mmol/l during the Sensor On arm than in the Sensor Off arm (19 vs 31 min/day; p = 0.009). The mean number of daily boluses increased in the Sensor On arm (6.8 ± 2.5 vs 5.8 ± 1.9, p < 0.0001), together with the frequency of use of the temporary basal rate (0.75 ± 1.11 vs 0.26 ± 0.47, p < 0.0001) and manual insulin suspend (0.91 ± 1.25 vs 0.70 ± 0.75, p < 0.018) functions. Four vs two events of severe hypoglycaemia occurred in the Sensor On and Sensor Off arm, respectively (p = 0.40). Continuous glucose monitoring was associated with decreased HbA(1c) levels and time spent in hypoglycaemia in individuals with type 1 diabetes using CSII. More frequent self-adjustments of insulin therapy may have contributed to these effects.

Fish oil supplementation and insulin sensitivity: a systematic review and meta-analysis.

PubMed

Gao, Huanqing; Geng, Tingting; Huang, Tao; Zhao, Qinghua

2017-07-03

Fish oil supplementation has been shown to be associated with a lower risk of metabolic syndrome and benefit a wide range of chronic diseases, such as cardiovascular disease, type 2 diabetes and several types of cancers. However, the evidence of fish oil supplementation on glucose metabolism and insulin sensitivity is still controversial. This meta-analysis summarized the exist evidence of the relationship between fish oil supplementation and insulin sensitivity and aimed to evaluate whether fish oil supplementation could improve insulin sensitivity. We searched the Cochrane Library, PubMed, Embase database for the relevant studies update to Dec 2016. Two researchers screened the literature independently by the selection and exclusion criteria. Studies were pooled using random effect models to estimate a pooled SMD and corresponding 95% CI. This meta-analysis was performed by Stata 13.1 software. A total of 17 studies with 672 participants were included in this meta-analysis study after screening from 498 published articles found after the initial search. In a pooled analysis, fish oil supplementation had no effects on insulin sensitivity compared with the placebo (SMD 0.17, 95%CI -0.15 to 0.48, p = 0.292). In subgroup analysis, fish oil supplementation could benefit insulin sensitivity among people who were experiencing at least one symptom of metabolic disorders (SMD 0.53, 95% CI 0.17 to 0.88, p < 0.001). Similarly, there were no significant differences between subgroups of methods of insulin sensitivity, doses of omega-3 polyunsaturated fatty acids (n-3 PUFA) of fish oil supplementation or duration of the intervention. The sensitivity analysis indicated that the results were robust. Short-term fish oil supplementation is associated with increasing the insulin sensitivity among those people with metabolic disorders.

Detecting intentional insulin omission for weight loss in girls with type 1 diabetes mellitus.

PubMed

Pinhas-Hamiel, Orit; Hamiel, Uri; Greenfield, Yuval; Boyko, Valentina; Graph-Barel, Chana; Rachmiel, Marianna; Lerner-Geva, Liat; Reichman, Brian

2013-12-01

Intentional insulin omission is a unique inappropriate compensatory behavior that occurs in patients with type 1 diabetes mellitus, mostly in females, who omit or restrict their required insulin doses in order to lose weight. Diagnosis of this underlying disorder is difficult. We aimed to use clinical and laboratory criteria to create an algorithm to assist in the detection of intentional insulin omission. The distribution of HbA1c levels from 287 (181 females) patients with type 1 diabetes were used as reference. Data from 26 patients with type 1 diabetes and intentional insulin omission were analysed. The Weka (Waikato Environment for Knowledge Analysis) machine learning software, decision tree classifier with 10-fold cross validation was used to developed prediction models. Model performance was assessed by cross-validation in a further 43 patients. Adolescents with intentional insulin omission were discriminated by: female sex, HbA1c>9.2%, more than 20% of HbA1c measurements above the 90th percentile, the mean of 3 highest delta HbA1c z-scores>1.28, current age and age at diagnosis. The models developed showed good discrimination (sensitivity and specificity 0.88 and 0.74, respectively). The external test dataset revealed good performance of the model with a sensitivity and specificity of 1.00 and 0.97, respectively. Using data mining methods we developed a clinical prediction model to determine an individual's probability of intentionally omitting insulin. This model provides a decision support system for the detection of intentional insulin omission for weight loss in adolescent females with type 1 diabetes mellitus. Copyright © 2013 Wiley Periodicals, Inc.

Association between insulin resistance and sustained virologic response in hepatitis C treatment, genotypes 1 versus 2 and 3: systematic literature review and meta-analysis.

PubMed

Laurito, Marcela Pezzoto; Parise, Edison Roberto

2013-01-01

Controversial results have been found in literature for the association between insulin resistance and sustained virologic response to standard chronic hepatitis C treatment. This study aims to provide a systematic literature review with meta-analysis, in order to evaluate if insulin resistance interferes with sustained virologic response in patients infected by the HCV genotype 1 versus HCV genotypes 2 and 3, undergoing treatment with interferon and ribavirin or pegylated interferon and ribavarin. Systematic search was performed on main electronic databases until May 2012. Primary outcome was sustained virologic response, defined as undetectable levels of HCV-RNA six months after the end of treatment. Meta-analytic measure was estimated using Dersimonian and Laird's method, using Stata software. Thirteen studies involving 2238 infected patients were included. There was a statistically significant association between insulin resistance and lower sustained virologic response rate, and this difference occurred in HCV genotype G1 (OR: 2.23; 95% CI: 1.59-3.13) and G2/G3 (OR: 4.45; 95% CI: 1.59-12.49). In addition, a difference was seen in the cut-offs used for defining insulin resistance by Homeostasis Model Assessment of Insulin Resistance. To minimize this limitation, sub-analysis that excluded the studies that did not use 2 as a cut-off value was performed and the results still demonstrated association between insulin resistance and sustained virologic response, for both genotypic groups. This meta-analysis provides evidence that elevated Homeostasis Model Assessment of Insulin Resistance is associated with a lower sustained virologic response rate in patients with hepatitis C treated with interferon and ribavirin or pegylated interferon and ribavarin, regardless of their genotype. Copyright © 2013 Elsevier Editora Ltda. All rights reserved.

[Integration to school of young children with type 1 diabetes on insulin pump therapy: parent's feed-back].

PubMed

Crosnier, H; Tubiana-Rufi, N

2013-12-01

There is an increase in the incidence of type 1 diabetes (T1D) in children younger than 5 years of age and continuous subcutaneous insulin infusion (CSII) appears to be an increasingly popular therapeutic option in France. A retrospective self-evaluation questionnaire was distributed to parents of young children with T1D treated by CSII (42 children, age 4.8±1.0 years, 2.3±0.5 years at the onset of TD1, mean± SD). It focused on the quality of diabetes management in daycare centers or with nannies and at school. Parental satisfaction related to the management of their children was overall good (84% for all the parents, 70.5% for the parents of children at nursery-school, from 3 to 6 years. However 93% of the parents experienced and overcame serious difficulties: exclusion of the children on account of DT1 (school trips, daycare centers after school), use of the pump for lunch and snacks, realization of glycemic controls, participation in school trips, survey during school meals. In spite of these difficulties these young children had a normal and safe time at school. The management of the young children with DT1, treated by CSII, in alternate care centers and at school need to be improved; the experience was positive when daycare workers and teachers agreed to be instructed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Consideration of Insulin Pumps or Continuous Glucose Monitors by Adolescents With Type 1 Diabetes and Their Parents: Stakeholder Engagement in the Design of Web-Based Decision Aids.

PubMed

Wysocki, Tim; Hirschfeld, Fiona; Miller, Louis; Izenberg, Neil; Dowshen, Steven A; Taylor, Alex; Milkes, Amy; Shinseki, Michelle T; Bejarano, Carolina; Kozikowski, Chelsea; Kowal, Karen; Starr-Ashton, Penny; Ross, Judith L; Kummer, Mark; Carakushansky, Mauri; Lyness, D'Arcy; Brinkman, William; Pierce, Jessica; Fiks, Alexander; Christofferson, Jennifer; Rafalko, Jessica; Lawson, Margaret L

2016-08-01

This article describes the stakeholder-driven design, development, and testing of web-based, multimedia decision aids for youth with type 1 diabetes who are considering the insulin pump or continuous glucose monitoring and their parents. This is the initial phase of work designed to develop and evaluate the efficacy of these decision aids in promoting improved decision-making engagement with use of a selected device. Qualitative interviews of 36 parents and adolescents who had previously faced these decisions and 12 health care providers defined the content, format and structure of the decision aids. Experts in children's health media helped the research team to plan, create, and refine multimedia content and its presentation. A web development firm helped organize the content into a user-friendly interface and enabled tracking of decision aid utilization. Throughout, members of the research team, adolescents, parents, and 3 expert consultants offered perspectives about the website content, structure, and function until the design was complete. With the decision aid websites completed, the next phase of the project is a randomized controlled trial of usual clinical practice alone or augmented by use of the decision aid websites. Stakeholder-driven development of multimedia, web-based decision aids requires meticulous attention to detail but can yield exceptional resources for adolescents and parents contemplating major changes to their diabetes regimens. © 2016 The Author(s).

V-Go Insulin Delivery System Versus Multiple Daily Insulin Injections for Patients With Uncontrolled Type 2 Diabetes Mellitus.

PubMed

Winter, Abigail; Lintner, Michaela; Knezevich, Emily

2015-04-21

Type 2 diabetes mellitus affects over 29.1 million Americans, diagnosed and undiagnosed. Achieving and maintaining glycemic control for these patients is of extreme importance when working to prevent complications and improve quality of life for patients. The V-Go is a newly developed insulin delivery system. The push of a button inserts a needle into the patient once daily and remains attached for 24 hours. The V-Go is designed to release a set basal rate throughout the day, while allowing patients to provide up to 36 units of on-demand bolus insulin with the manual click of 2 buttons. It is a spring-loaded device filled daily with rapid-acting insulin that runs without the use of batteries or computer software. The main objective of this prospective active comparator study was to observe the A1C lowering effects of multiple daily insulin injections (MDII) versus the use of the V-Go insulin delivery system for patients with uncontrolled type 2 diabetes mellitus over a 3-month period. In addition, the effect on insulin requirement for these patients was assessed with secondary comparisons of weight, blood pressure, prevalence of hypoglycemic events, and quality of life before and after 3 months of intensified insulin therapy with regular monitoring by a clinical pharmacist at an internal medicine clinic. The average A1C lowering experienced by the 3 patients in the V-Go group was 1.5%, while the average A1C change in the 3 patients in the MDII group was an increase of 0.2%. All patients in the V-Go group experienced a decrease in insulin total daily dose (TDD), with an average decrease of 26.3 units. All patients in the MDII group experienced an increase in insulin TDD with an average of 15 units daily to achieve therapeutic goals individualized for each patient. All patients who underwent intensification of insulin therapy experienced an increase in subjective quality of life (QOL) as determined using the Diabetes-39 (D-39) questionnaire, though QOL results lacked statistical significance. © 2015 Diabetes Technology Society.

PumpKin: A tool to find principal pathways in plasma chemical models

NASA Astrophysics Data System (ADS)

Markosyan, A. H.; Luque, A.; Gordillo-Vázquez, F. J.; Ebert, U.

2014-10-01

PumpKin is a software package to find all principal pathways, i.e. the dominant reaction sequences, in chemical reaction systems. Although many tools are available to integrate numerically arbitrarily complex chemical reaction systems, few tools exist in order to analyze the results and interpret them in relatively simple terms. In particular, due to the large disparity in the lifetimes of the interacting components, it is often useful to group reactions into pathways that recycle the fastest species. This allows a researcher to focus on the slow chemical dynamics, eliminating the shortest timescales. Based on the algorithm described by Lehmann (2004), PumpKin automates the process of finding such pathways, allowing the user to analyze complex kinetics and to understand the consumption and production of a certain species of interest. We designed PumpKin with an emphasis on plasma chemical systems but it can also be applied to atmospheric modeling and to industrial applications such as plasma medicine and plasma-assisted combustion.

Internet-based interface for STRMDEPL08

USGS Publications Warehouse

Reeves, Howard W.; Asher, A. Jeremiah

2010-01-01

The core of the computer program STRMDEPL08 that estimates streamflow depletion by a pumping well with one of four analytical solutions was re-written in the Javascript software language and made available through an internet-based interface (web page). In the internet-based interface, the user enters data for one of the four analytical solutions, Glover and Balmer (1954), Hantush (1965), Hunt (1999), and Hunt (2003), and the solution is run for constant pumping for a desired number of simulation days. Results are returned in tabular form to the user. For intermittent pumping, the interface allows the user to request that the header information for an input file for the stand-alone executable STRMDEPL08 be created. The user would add the pumping information to this header information and run the STRMDEPL08 executable that is available for download through the U.S. Geological Survey. Results for the internet-based and stand-alone versions of STRMDEPL08 are shown to match.

Simulation of the thermal performance of a hybrid solar-assisted ground-source heat pump system in a school building

NASA Astrophysics Data System (ADS)

Androulakis, N. D.; Armen, K. G.; Bozis, D. A.; Papakostas, K. T.

2018-04-01

A hybrid solar-assisted ground-source heat pump (SAGSHP) system was designed, in the frame of an energy upgrade study, to serve as a heating system in a school building in Greece. The main scope of this study was to examine techniques to reduce the capacity of the heating equipment and to keep the primary energy consumption low. Simulations of the thermal performance of both the building and of five different heating system configurations were performed by using the TRNSYS software. The results are presented in this work and show that the hybrid SAGSHP system displays the lower primary energy consumption among the systems examined. A conventional ground-source heat pump system has the same primary energy consumption, while the heat pump's capacity is double and the ground heat exchanger 2.5 times longer. This work also highlights the contribution of simulation tools to the design of complex heating systems with renewable energy sources.

Geometric Optimization for Non-Thrombogenicity of a Centrifugal Blood Pump through Flow Visualization

NASA Astrophysics Data System (ADS)

Toyoda, Masahiro; Nishida, Masahiro; Maruyama, Osamu; Yamane, Takashi; Tsutsui, Tatsuo; Sankai, Yoshiyuki

A monopivot centrifugal blood pump, whose impeller is supported with a pivot bearing and a passive magnetic bearing, is under development for implantable artificial heart. The hemolysis level is less than that of commercial centrifugal pumps and the pump size is as small as 160 mL in volume. To solve a problem of thrombus caused by fluid dynamics, flow visualization experiments and animal experiments have been undertaken. For flow visualization a three-fold scale-up model, high-speed video system, and particle tracking velocimetry software were used. To verify non-thrombogenicity one-week animal experiments were conducted with sheep. The initially observed thrombus around the pivot was removed through unifying the separate washout holes to a small centered hole to induce high shear around the pivot. It was found that the thrombus contours corresponded to the shear rate of 300s-1 for red thrombus and 1300-1700s-1 for white thrombus, respectively. Thus flow visualization technique was found to be a useful tool to predict thrombus location.

Robust modeling and performance analysis of high-power diode side-pumped solid-state laser systems.

PubMed

Kashef, Tamer; Ghoniemy, Samy; Mokhtar, Ayman

2015-12-20

In this paper, we present an enhanced high-power extrinsic diode side-pumped solid-state laser (DPSSL) model to accurately predict the dynamic operations and pump distribution under different practical conditions. We introduce a new implementation technique for the proposed model that provides a compelling incentive for the performance assessment and enhancement of high-power diode side-pumped Nd:YAG lasers using cooperative agents and by relying on the MATLAB, GLAD, and Zemax ray tracing software packages. A large-signal laser model that includes thermal effects and a modified laser gain formulation and incorporates the geometrical pump distribution for three radially arranged arrays of laser diodes is presented. The design of a customized prototype diode side-pumped high-power laser head fabricated for the purpose of testing is discussed. A detailed comparative experimental and simulation study of the dynamic operation and the beam characteristics that are used to verify the accuracy of the proposed model for analyzing the performance of high-power DPSSLs under different conditions are discussed. The simulated and measured results of power, pump distribution, beam shape, and slope efficiency are shown under different conditions and for a specific case, where the targeted output power is 140 W, while the input pumping power is 400 W. The 95% output coupler reflectivity showed good agreement with the slope efficiency, which is approximately 35%; this assures the robustness of the proposed model to accurately predict the design parameters of practical, high-power DPSSLs.

Lunar Base Heat Pump

NASA Technical Reports Server (NTRS)

Walker, D.; Fischbach, D.; Tetreault, R.

1996-01-01

The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

Sensor-augmented pump therapy in very young children with type 1 diabetes: an efficacy and feasibility observational study.

PubMed

Frontino, Giulio; Bonfanti, Riccardo; Scaramuzza, Andrea; Rabbone, Ivana; Meschi, Franco; Rigamonti, Andrea; Battaglino, Roseila; Favalli, Valeria; Bonura, Clara; Sicignano, Sabrina; Gioia, Elisa; Zuccotti, Gian Vincenzo; Cerutti, Franco; Chiumello, Giuseppe

2012-09-01

Efficacy and feasibility of sensor-augmented pump (SAP) therapy were evaluated in very young children with type 1 diabetes (T1D). SAP (Dexcom [San Diego, CA] Seven Plus™ usage combined with insulin pump) therapy was retrospectively evaluated in 28 children (15 boys) younger than 7 years (mean age, 5.8 ± 1.2 years; range, 3-7 years), with T1D. Glycosylated hemoglobin (HbA1c) was evaluated at baseline and at the end of the study, as were efficacy and feasibility of the system, using a rating scale (with 3 being the most positive). SAP has been used for at least 6 months by 85% of patients, with an overall good satisfaction (92%). The greatest perceived benefit was the reduced fear of hypoglycemia (score of 3, 81%). HbA1c significantly improved only in patients with baseline HbA1c >7.5% (P = 0.026). SAP therapy is effective and feasible in preschool children with T1D. In patients with high HbA1c at baseline it provide a 0.9% decrease, sustained for at least 6 months.

"Do-It-Yourself" reliable pH-stat device by using open-source software, inexpensive hardware and available laboratory equipment

PubMed Central

Kragic, Rastislav; Kostic, Mirjana

2018-01-01

In this paper, we present the construction of a reliable and inexpensive pH stat device, by using open-source “OpenPhControl” software, inexpensive hardware (a peristaltic and a syringe pump, Arduino, a step motor…), readily available laboratory devices: a pH meter, a computer, a webcam, and some 3D printed parts. We provide a methodology for the design, development and test results of each part of the device, as well as of the entire system. In addition to dosing reagents by means of a low-cost peristaltic pump, we also present carefully controlled dosing of reagents by an open-source syringe pump. The upgrading of the basic open-source syringe pump is given in terms of pump control and application of a larger syringe. In addition to the basic functions of pH stat, i.e. pH value measurement and maintenance, an improvement allowing the device to be used for potentiometric titration has been made as well. We have demonstrated the device’s utility when applied for cellulose fibers oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl radical, i.e. for TEMPO-mediated oxidation. In support of this, we present the results obtained for the oxidation kinetics, the consumption of added reagent and experimental repeatability. Considering that the open-source scientific tools are available to everyone, and that researchers can construct and adjust the device according to their needs, as well as, that the total cost of the open-source pH stat device, excluding the existing laboratory equipment (pH meter, computer and glossary) was less than 150 EUR, we believe that, at a small fraction of the cost of available commercial offers, our open-source pH stat can significantly improve experimental work where the use of pH stat is necessary. PMID:29509793

"Do-It-Yourself" reliable pH-stat device by using open-source software, inexpensive hardware and available laboratory equipment.

PubMed

Milanovic, Jovana Z; Milanovic, Predrag; Kragic, Rastislav; Kostic, Mirjana

2018-01-01

In this paper, we present the construction of a reliable and inexpensive pH stat device, by using open-source "OpenPhControl" software, inexpensive hardware (a peristaltic and a syringe pump, Arduino, a step motor…), readily available laboratory devices: a pH meter, a computer, a webcam, and some 3D printed parts. We provide a methodology for the design, development and test results of each part of the device, as well as of the entire system. In addition to dosing reagents by means of a low-cost peristaltic pump, we also present carefully controlled dosing of reagents by an open-source syringe pump. The upgrading of the basic open-source syringe pump is given in terms of pump control and application of a larger syringe. In addition to the basic functions of pH stat, i.e. pH value measurement and maintenance, an improvement allowing the device to be used for potentiometric titration has been made as well. We have demonstrated the device's utility when applied for cellulose fibers oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl radical, i.e. for TEMPO-mediated oxidation. In support of this, we present the results obtained for the oxidation kinetics, the consumption of added reagent and experimental repeatability. Considering that the open-source scientific tools are available to everyone, and that researchers can construct and adjust the device according to their needs, as well as, that the total cost of the open-source pH stat device, excluding the existing laboratory equipment (pH meter, computer and glossary) was less than 150 EUR, we believe that, at a small fraction of the cost of available commercial offers, our open-source pH stat can significantly improve experimental work where the use of pH stat is necessary.

Bolus Guide: A Novel Insulin Bolus Dosing Decision Support Tool Based on Selection of Carbohydrate Ranges

PubMed Central

Shapira, Gali; Yodfat, Ofer; HaCohen, Arava; Feigin, Paul; Rubin, Richard

2010-01-01

Background Optimal continuous subcutaneous insulin infusion (CSII) therapy emphasizes the relationship between insulin dose and carbohydrate consumption. One widely used tool (bolus calculator) requires the user to enter discrete carbohydrate values; however, many patients might not estimate carbohydrates accurately. This study assessed carbohydrate estimation accuracy in type 1 diabetes CSII users and compared simulated blood glucose (BG) outcomes using the bolus calculator and the “bolus guide,” an alternative system based on ranges of carbohydrate load. Methods Patients (n = 60) estimated the carbohydrate load of a representative sample of meals of known carbohydrate value. The estimated error distribution [coefficient of variation (CV)] was the basis for a computer simulation (n = 1.6 million observations) of insulin recommendations for the bolus guide and bolus calculator, translated into outcome blood glucose (OBG) ranges (≤60, 61–200, >201 mg/dl). Patients (n = 30) completed questionnaires assessing satisfaction with the bolus guide. Results The CV of typical meals ranged from 27.9% to 44.5%. The percentage of simulated OBG for the calculator and the bolus guide in the <60 mg/dl range were 20.8% and 17.2%, respectively, and 13.8% and 15.8%, respectively, in the >200 mg/dl range. The mean and median scores of all bolus guide satisfaction items and ease of learning and use were 4.17 and 4.2, respectively (of 5.0). Conclusion The bolus guide recommendation based on carbohydrate range selection is substantially similar to the calculator based on carbohydrate point estimation and appears to be highly accepted by type 1 diabetes insulin pump users. PMID:20663453

Does treatment with an insulin pump improve glycaemic control in children and adolescents with type 1 diabetes? A retrospective case-control study.

PubMed

Brorsson, Anna Lena; Viklund, Gunnel; Örtqvist, Eva; Lindholm Olinder, Anna

2015-11-01

To investigate long-term effects on glycaemic control, ketoacidosis, serious hypoglycaemic events, insulin requirements, and body mass index standard deviation scores (BMI-SDS) in children and adolescents with type 1 diabetes starting on continuous subcutaneous insulin infusion (CSII) compared with children and adolescents treated with multiple daily injections (MDI). This retrospective case-control study compares 216 patients starting CSII with a control group on MDI (n = 215), matched for glycated hemoglobin (HbA1c), sex, and age during a 2-yr period. Variables collected were gender, age, HbA1c, insulin requirement, BMI, BMI-SDS, ketoacidosis, and serious hypoglycaemic events. In the CSII group there was an improvement in HbA1c after 6 and 12 months compared with the MDI group. For boys and girls separately the same effect was detected after 6 months, but only for boys after 12 months. The incidence of ketoacidosis was higher in the CSII group compared with the MDI group (2.8 vs. 0.5/100 person-yr). The incidences of severe hypoglycaemic episodes per 100 person-yr were three in the CSII group and six in the MDI group (p < 0.05). After 6, 12, and 24 months, the insulin requirement was higher in the MDI group. This study shows that treatment with CSII resulted in an improvement in HbA1c levels up to 1 yr and decreased the number of severe hypoglycaemic events, but the frequency of ketoacidosis increased. The major challenge is to identify methods to maintain the HbA1c improvement, especially among older children and teenagers, and reduce the frequency of ketoacidosis. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Direct Diabetes-Related Costs in Young Patients with Early-Onset, Long-Lasting Type 1 Diabetes

PubMed Central

Straßburger, Klaus; Flechtner-Mors, Marion; Hungele, Andreas; Beyer, Peter; Placzek, Kerstin; Hermann, Ulrich; Schumacher, Andrea; Freff, Markus; Stahl-Pehe, Anna

2013-01-01

Objective To estimate diabetes-related direct health care costs in pediatric patients with early-onset type 1 diabetes of long duration in Germany. Research Design and Methods Data of a population-based cohort of 1,473 subjects with type 1 diabetes onset at 0–4 years of age within the years 1993–1999 were included (mean age 13.9 (SD 2.2) years, mean diabetes duration 10.9 (SD 1.9) years, as of 31.12.2007). Diabetes-related health care services utilized in 2007 were derived from a nationwide prospective documentation system (DPV). Health care utilization was valued in monetary terms based on inpatient and outpatient medical fees and retail prices (perspective of statutory health insurance). Multiple regression models were applied to assess associations between direct diabetes-related health care costs per patient-year and demographic and clinical predictors. Results Mean direct diabetes-related health care costs per patient-year were €3,745 (inter-quartile range: 1,943–4,881). Costs for glucose self-monitoring were the main cost category (28.5%), followed by costs for continuous subcutaneous insulin infusion (25.0%), diabetes-related hospitalizations (22.1%) and insulin (18.4%). Female gender, pubertal age and poor glycemic control were associated with higher and migration background with lower total costs. Conclusions Main cost categories in patients with on average 11 years of diabetes duration were costs for glucose self-monitoring, insulin pump therapy, hospitalization and insulin. Optimization of glycemic control in particular in pubertal age through intensified care with improved diabetes education and tailored insulin regimen, can contribute to the reduction of direct diabetes-related costs in this patient group. PMID:23967077

Comparison of treatment with continuous subcutaneous insulin infusion versus multiple daily insulin injections with bolus calculator in patients with type 1 diabetes.

PubMed

Pérez-García, L; Goñi-Iriarte, M J; García-Mouriz, M

2015-01-01

A study of the glycemic control, quality of life, and fear and perception of hypoglycemia by comparing continuous subcutaneous insulin infusion (CSII) group with multiple daily inyections (MDI) with bolus calculator group. This is a retrospective cohort study with following up during the first 12 months that CSII group (n=30) begins the use of "bolus wizard" and the MDI-calculator (n=30) group begins the use of the bolus calculator (Accu-Chek(®) Aviva Expert). HbA1c (3, 6 and 12 months). Questionnaires used: EsDQOL (quality of life), FH-15 (fear of hypoglycemia), and Clarke (perception of hypoglycemia). T Student and nonparametric tests. The average reduction in HbA1c during the study was significantly higher in CSII group (-0.56±0.84%) compared with the MDI group (0.097±0.94%), P=.028. The average basal insulin dose was significantly higher in the MDI group (at baseline, 6 and 12 months). No significant differences were found between the 2 treatment groups after analyzing the EsDQOL, FH-15 and Clarke questionnaires. In the CSII group, perceived quality of life assessed by the EsDQOL questionnaire was found to be better at the end of the study than at the beginning of using the insulin pump. The average reduction in HbA1c was significantly higher in the CSII group. In the CSII group, perceived quality of life was better at the end of the study than at the beginning. Copyright © 2014 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Microbial load monitor

NASA Technical Reports Server (NTRS)

Caplin, R. S.; Royer, E. R.

1977-01-01

Design analysis of a microbial load monitor system flight engineering model was presented. Checkout of the card taper and media pump system was fabricated as well as the final two incubating reading heads, the sample receiving and card loading device assembly, related sterility testing, and software. Progress in these areas was summarized.

SIMWEST: A simulation model for wind and photovoltaic energy storage systems (CDC user's manual), volume 1

NASA Technical Reports Server (NTRS)

Warren, A. W.; Esinger, A. W.

1979-01-01

Procedures are given for using the SIMWEST program on CDC 6000 series computers. This expanded software package includes wind and/or photovoltaic systems utilizing any combination of five types of storage (pumped hydro, battery, thermal, flywheel, and pneumatic).

Variability of Basal Rate Profiles in Insulin Pump Therapy and Association with Complications in Type 1 Diabetes Mellitus.

PubMed

Laimer, Markus; Melmer, Andreas; Mader, Julia K; Schütz-Fuhrmann, Ingrid; Engels, Heide-Rose; Götz, Gabriele; Pfeifer, Martin; Hermann, Julia M; Stettler, Christoph; Holl, Reinhard W

2016-01-01

Traditionally, basal rate profiles in continuous subcutaneous insulin infusion therapy are individually adapted to cover expected insulin requirements. However, whether this approach is indeed superior to a more constant BR profile has not been assessed so far. This study analysed the associations between variability of BR profiles and acute and chronic complications in adult type 1 diabetes mellitus. BR profiles of 3118 female and 2427 male patients from the "Diabetes-Patienten-Verlaufsdokumentation" registry from Germany and Austria were analysed. Acute and chronic complications were recorded 6 months prior and after the most recently documented basal rate. The "variability index" was calculated as variation of basal rate intervals in percent and describes the excursions of the basal rate intervals from the median basal rate. The variability Index correlated positively with severe hypoglycemia (r = .06; p<0.001), hypoglycemic coma (r = .05; p = 0.002), and microalbuminuria (r = 0.05; p = 0.006). In addition, a higher variability index was associated with higher frequency of diabetic ketoacidosis (r = .04; p = 0.029) in male adult patients. Logistic regression analysis adjusted for age, gender, duration of disease and total basal insulin confirmed significant correlations of the variability index with severe hypoglycemia (β = 0.013; p<0.001) and diabetic ketoacidosis (β = 0.012; p = 0.017). Basal rate profiles with higher variability are associated with an increased frequency of acute complications in adults with type 1 diabetes.

Closed-Loop Insulin Delivery for Adults with Type 1 Diabetes Undertaking High-Intensity Interval Exercise Versus Moderate-Intensity Exercise: A Randomized, Crossover Study.

PubMed

Jayawardene, Dilshani C; McAuley, Sybil A; Horsburgh, Jodie C; Gerche, André La; Jenkins, Alicia J; Ward, Glenn M; MacIsaac, Richard J; Roberts, Timothy J; Grosman, Benyamin; Kurtz, Natalie; Roy, Anirban; O'Neal, David N

2017-06-01

We aimed to compare closed-loop glucose control for people with type 1 diabetes undertaking high-intensity interval exercise (HIIE) versus moderate-intensity exercise (MIE). Adults with type 1 diabetes established on insulin pumps undertook HIIE and MIE stages in random order during automated insulin delivery via a closed-loop system (Medtronic). Frequent venous sampling for glucose, lactate, ketones, insulin, catecholamines, cortisol, growth hormone, and glucagon levels was performed. The primary outcome was plasma glucose <4.0 mmol/L for ≥15 min, from exercise commencement to 120 min postexercise. Secondary outcomes included continuous glucose monitoring and biochemical parameters. Twelve adults (age mean ± standard deviation 40 ± 13 years) were recruited; all completed the study. Plasma glucose of one participant fell to 3.4 mmol/L following MIE completion; no glucose levels were <4.0 mmol/L for HIIE (primary outcome). There were no glucose excursions >15.0 mmol/L for either stage. Mean (±standard error) plasma glucose did not differ between stages pre-exercise; was higher during exercise in HIIE than MIE (11.3 ± 0.5 mmol/L vs. 9.7 ± 0.6 mmol/L, respectively; P < 0.001); and remained higher until 60 min postexercise. There were no differences in circulating free insulin before, during, or postexercise. During HIIE compared with MIE, there were greater increases in lactate (P < 0.001), catecholamines (all P < 0.05), and cortisol (P < 0.001). Ketones increased more with HIIE than MIE postexercise (P = 0.031). Preliminary findings suggest that closed-loop glucose control is safe for people undertaking HIIE and MIE. However, the management of the postexercise rise in ketones secondary to counter-regulatory hormone-induced insulin resistance observed with HIIE may represent a challenge for closed-loop systems.

Development of a cross-disciplinary continuous insulin infusion protocol for non-critically ill patients in a French university hospital.

PubMed

Bernard, Lise; Roche, Béatrice; Batisse, Marie; Maqdasy, Salwan; Terral, Daniel; Sautou, Valérie; Tauveron, Igor

2016-10-01

In non-critically ill patients, the use of an insulin syringe pump allows the management of temporary situations during which other therapies cannot be used (failure of subcutaneous injections, awaiting advice from the diabetes team, emergency situations, prolonged corticosteroid therapy, initiation of an artificial nutrition, need for a fasting status, etc.). To manage the risks related to this «never event», the use of a standard validated protocol for insulin administration and monitoring is an essential prerequisite. To this end, a multidisciplinary approach is recommended. With the support of our subcommission «Endocrinology-Diabetology», we proceeded with a «step-by-step process» to create such a standardized protocol: (1) review of all existing protocols in our hospital; (2) overview of the literature data concerning insulin infusion protocols developed by multidisciplinary teams in France and abroad; (3) development of a standardized protocol for non-intensive care unit patients, respecting the current recommendations and adapting it to the working habits of health teams; and (4) validation of the protocol Two protocols based on the same structure but adapted to the health status of the patient have been developed. The protocols are divided in to three parts: (1) golden rules to make the use of the protocol appropriate and safe; (2) the algorithm (a double entry table) corresponding to a dynamic adaptation of insulin doses, clearly defining the target and the 'at risk situations'; and (3) practical aspects of the protocol: preparation of the syringe, treatment initiation and traceability. The protocols have been validated by the institution. Our standardized insulin infusion protocol is simple, easy to implement, safe and is likely to be applicable in diverse care units. However, the efficiency, safety and the workability of our protocols have to be clinically evaluated. © 2016 John Wiley & Sons, Ltd.

Optimization of the intravenous glucose tolerance test in T2DM patients using optimal experimental design.

PubMed

Silber, Hanna E; Nyberg, Joakim; Hooker, Andrew C; Karlsson, Mats O

2009-06-01

Intravenous glucose tolerance test (IVGTT) provocations are informative, but complex and laborious, for studying the glucose-insulin system. The objective of this study was to evaluate, through optimal design methodology, the possibilities of more informative and/or less laborious study design of the insulin modified IVGTT in type 2 diabetic patients. A previously developed model for glucose and insulin regulation was implemented in the optimal design software PopED 2.0. The following aspects of the study design of the insulin modified IVGTT were evaluated; (1) glucose dose, (2) insulin infusion, (3) combination of (1) and (2), (4) sampling times, (5) exclusion of labeled glucose. Constraints were incorporated to avoid prolonged hyper- and/or hypoglycemia and a reduced design was used to decrease run times. Design efficiency was calculated as a measure of the improvement with an optimal design compared to the basic design. The results showed that the design of the insulin modified IVGTT could be substantially improved by the use of an optimized design compared to the standard design and that it was possible to use a reduced number of samples. Optimization of sample times gave the largest improvement followed by insulin dose. The results further showed that it was possible to reduce the total sample time with only a minor loss in efficiency. Simulations confirmed the predictions from PopED. The predicted uncertainty of parameter estimates (CV) was low in all tested cases, despite the reduction in the number of samples/subject. The best design had a predicted average CV of parameter estimates of 19.5%. We conclude that improvement can be made to the design of the insulin modified IVGTT and that the most important design factor was the placement of sample times followed by the use of an optimal insulin dose. This paper illustrates how complex provocation experiments can be improved by sequential modeling and optimal design.

A new variation in the promoter region, the -604 C>T, and the Leu72Met polymorphism of the ghrelin gene are associated with protection to insulin resistance.

PubMed

Zavarella, S; Petrone, A; Zampetti, S; Gueorguiev, M; Spoletini, M; Mein, C A; Leto, G; Korbonits, M; Buzzetti, R

2008-04-01

Previous studies suggested that polymorphisms in the coding region of the preproghrelin were involved in the etiology of obesity and might modulate glucose-induced insulin secretion. We evaluated the association of a new variation, -604C>T, in the promoter region of the ghrelin gene, of Leu72Met (247C>A) and of Gln90Leu (265A>T), all haplotype-tagging single nucleotide polymorphisms (SNPs), with measures of insulin sensitivity in 1420 adult individuals. The three SNPs were genotyped using ABI PRISM 7900 HT Sequence Detection System. We used multiple linear regression analysis for quantitative traits and THESIAS software for haplotype analysis. We observed a protective effect exerted by Met72 variant of Leu72Met SNP on insulin resistance parameters; a significant decreasing trend from Leu/Leu to Leu/Met and to Met/Met homozygous subjects in triglycerides, fasting insulin levels and HOMA-IR index (P=0.02, 0.01 and 0.003, respectively), and, consistently, an increase in ghrelin levels (P=0.003) was found. A significant decrease from CC to TC and to TT genotypes in insulin levels and HOMA-IR index was also detected (P=0.00l for both), but only in subjects homozygous for Leu72, where the protective effect of Met72 was not present. The haplotype analysis results supported the data obtained by the evaluation of each single SNP, showing the highest value of insulin levels and HOMA-IR index in the -604(c)247(c) haplotype intermediate value in -604(T)247(C) and lowest value in -604(C)247(A). Our observations suggest a protective role of the Met72 variant and of -604 T allele in modulating insulin resistance. These SNPs or an unknown functional variant in linkage disequilibrium could increase ghrelin levels and probably insulin sensitivity.

Vacuum system of the cyclotrons in VECC, Kolkata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Anindya; Bhole, R.B.; Akhtar, J.

2011-07-01

The vacuum system of the K=130 Room Temperature Cyclotron (RTC) (operational since 1978) has been recently modernized and the same of the K{sub bend}=520 Superconducting Cyclotron (SCC), currently under commissioning, is being deployed for remote monitoring and control. The vacuum system of RTC is designed to achieve and maintain vacuum level of 2 X 10{sup -6} mbar inside 23 m{sup 3} volume of Resonator tank and DEE tank. This has been upgraded by replacing several valves, Freon units, gauges and pumps. The relay based manual control system has been replaced by PLC based automated system. The SCC vacuum system alsomore » has an elaborate arrangement comprising of turbo molecular pumping modules with associated isolation valves and characteristic gauges. This paper describes essential elements, typically used to obtain high (1X10{sup -7} mbar) vacuum using rotary pumps, diffusion pumps and cold traps/turbo-molecular pumps and other system components such as valves, gauges and baffles. The supervisory control methodology/scheme of both the vacuum systems, developed in-house using EPICS (Experimental Physics and Industrial Control System), a standard open-source software tool for designing distributed control system, is also elaborated here. (author)« less

Seasonal performance for Heat pump with vertical ground heat exchanger in Riga

NASA Astrophysics Data System (ADS)

Jaundālders, S.; Stanka, P.; Rusovs, D.

2017-10-01

Experimental measurements of Seasonal Coefficient of Performance (SCOP) for heating of 160 m2 household in Riga were conducted for operation of brine-water heat pump with vertical ground heat exchangers (GHE). Data regarding heat and electrical power consumption were recorded during three-year period from 2013 to 2016. Vapor compression heat pump has heat energy output of 8 kW. GHE consists of three boreholes. Each borehole is 60 m deep. Data regarding brine temperature for borehole input and output were presented and discussed. As far as house had floor heating, there were presented data about COP for B0/W35 and its dependence from room and outdoor temperature during heating season. Empirical equation was created. Average heat energy consumption during one year for heating was 72 kWh/m2 measured by heat meter. Detected primary energy consumption (electrical energy from grid) was 21 kWh/m2 which resulted in SCOP=3.8. These data were compared with SCOP for air-to-water heat pump in Latvia and available configuration software for heat pumps operation. Good agreement between calculated performance and reported experimental data were founded.

Continuous glucose monitoring for patients with diabetes: an evidence-based analysis.

PubMed

2011-01-01

To determine the effectiveness and cost-effectiveness of continuous glucose monitoring combined with self-monitoring of blood glucose compared with self-monitoring of blood glucose alone in the management of diabetes. CONDITION AND TARGET POPULATION Diabetes is a chronic metabolic disorder that interferes with the body's ability to produce or effectively use insulin. In 2005, an estimated 816,000 Ontarians had diabetes representing 8.8% of the province's population. Type 1 or juvenile onset diabetes is a life-long disorder that commonly manifests in children and adolescents. It represents about 10% of the total diabetes population and involves immune-mediated destruction of insulin producing cells in the pancreas. The loss of these cells necessitates insulin therapy. Type 2 or "adult-onset" diabetes represents about 90% of the total diabetes population and is marked by a resistance to insulin or insufficient insulin secretion. The risk of developing type 2 diabetes increases with age, obesity and lack of physical activity. Approximately 30% of patients with type 2 diabetes eventually require insulin therapy. Continuous glucose monitors (CGM) measure glucose levels in the interstitial fluid surrounding skin cells. These measurements supplement conventional self monitoring of blood glucose (SMBG) by monitoring the glucose fluctuations continuously over a stipulated period of time, thereby identifying fluctuations that would not be identified with SMBG alone. To use a CGM, a sensor is inserted under the skin to measure glucose in the interstitial fluid. The sensor is wired to a transmitter. The device requires calibration using a capillary blood glucose measurement. Each sensor continuously measures glucose every 5-10 seconds averaging these values every 5 minutes and storing this data in the monitors memory. Depending on the device used, the algorithm in the device can measure glucose over a 3 or 6 day period using one sensor. After the 3 or 6 day period, a new sensor is required. The device is equipped with alarms which warn the patient of impending hypo-or hyperglycemia. Two types of CGM are available: Systems that is stored in a monitor and can be downloaded later.Real time systems that continuously provide the actual glucose concentration on a display. What is the effectiveness and cost-effectiveness of CGM combined with SMBG compared with SMBG alone in the management of diabetes? A literature search was performed on September 15, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 2002 until September 15, 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology. English languageRandomized controlled trials (N>30 patients)Adults or pediatric patients with insulin dependent diabetes (type 1 or 2 or gestational)Studies comparing CGM plus SMBG versus SMBG alone Case studiesStudies that did not compare CGM plus SMBG versus SMBG aloneStudies that did not report statistical analysis of outcomes or data was unextractable Change in glycosylated hemoglobin (HbA1c)Frequency or duration of hypo-or hyperglycemic episodes or euglycemiaAdverse effects Moderate quality evidence that CGM + SMBG: is not more effective than self monitoring of blood glucose (SMBG) alone in the reduction of HbA1c using insulin infusion pumps for Type 1 diabetes.is not more effective than SMBG alone in the reduction of hypoglycemic or severe hypoglycemic events using insulin infusion pumps for Type 1 diabetes.

Automated bolus advisor control and usability study (ABACUS): does use of an insulin bolus advisor improve glycaemic control in patients failing multiple daily insulin injection (MDI) therapy? [NCT01460446

PubMed Central

2012-01-01

Background People with T1DM and insulin-treated T2DM often do not follow and/or adjust their insulin regimens as needed. Key contributors to treatment non-adherence are fear of hypoglycaemia, difficulty and lack of self-efficacy associated with insulin dose determination. Because manual calculation of insulin boluses is both complex and time consuming, people may rely on empirical estimates, which can result in persistent hypoglycaemia and/or hyperglycaemia. Use of automated bolus advisors (BA) has been shown to help insulin pump users to more accurately meet prandial insulin dosage requirements, improve postprandial glycaemic excursions, and achieve optimal glycaemic control with an increased time within optimal range. Use of a BA containing an early algorithm based on sliding scales for insulin dosing has also been shown to improve HbA1c levels in people treated with multiple daily insulin injections (MDI). We designed a study to determine if use of an automated BA can improve clinical and psychosocial outcomes in people treated with MDI. Methods/design The Automated Bolus Advisor Control and Usability Study (ABACUS) is a 6-month, prospective, randomised, multi-centre, multi-national trial to determine if automated BA use improves glycaemic control as measured by a change in HbA1c in people using MDI with elevated HbA1c levels (#62;7.5%). A total of 226 T1DM and T2DM participants will be recruited. Anticipated attrition of 20% will yield a sample size of 90 participants, which will provide #62;80% power to detect a mean difference of 0.5%, with SD of 0.9%, using a one-sided 5% t-test, with 5% significance level. Other measures of glycaemic control, self-care behaviours and psychosocial issues will also be assessed. Discussion It is critical that healthcare providers utilise available technologies that both facilitate effective glucose management and address concerns about safety and lifestyle. Automated BAs may help people using MDI to manage their diabetes more effectively and minimise the risk of long-term diabetes related complications. Findings from a recent study suggest that BA use positively addresses both safety and lifestyle concerns; however, randomised trials are needed to confirm these perceptions and determine whether bolus advisor use improves clinical outcomes. Our study is designed to make these assessments. Trial registration NCT01460446 PMID:23062116

The first object oriented monitor for intravenous anesthesia.

PubMed

Cantraine, F R; Coussaert, E J

2000-01-01

To describe the design and implementation of "INFUSION TOOLBOX," a software tool to control and monitor multiple intravenous drug infusions simultaneously using pharmacokinetic and pharmacodynamic principles. INFUSION TOOLBOX has been designed to present a graphical interface. Object Oriented design was used and the software was implemented using Smalltalk, to run on a PC. Basic tools are available to manage patient, drugs, pumps and reports. These tools are the PatientPanel, the DrugPanel, the PumpPanel and the HistoryPanel. The screen is built dynamically. The panels may be collapsed or closed to avoid a crowded display. We also built control panels such as the Target ControlPanel which calculates the best infusion sequence to bring the drug concentration in the plasma compartment to a preset value. Before drug delivery, the user enters the patient's data, selects a drug, enters its dilution factor and chooses a pharmacokinetic model. The calculated plasma concentration is continually displayed and updated. The anesthetist may ask for the history of the delivery to obtain a graphic report or to add events to the logbook. A panel targeting the effect is used when a pharmacodynamic model is known. Data files for drugs, pumps and surgery are upgradable. By creating a resizeable ControlPanel we enable the anesthetist to display the information he wishes, when he wishes it. The available panels are diverse enough to meet the anesthetist needs; they may be adapted to the drug used, pumps used and surgery. It is the anesthetist who builds dynamically its different control screens. By adopting an evolutionary solution model we have achieved considerable success in building our drug delivery monitor. In addition we have gained valuable insight into the anesthesia information domain that will allow us to further enhance and expand the system.

Low threshold and high efficiency solar-pumped laser with Fresnel lens and a grooved Nd:YAG rod

NASA Astrophysics Data System (ADS)

Guan, Zhe; Zhao, Changming; Yang, Suhui; Wang, Yu; Ke, Jieyao; Gao, Fengbin; Zhang, Haiyang

2016-11-01

Sunlight is considered as a new efficient source for direct optical-pumped solid state lasers. High-efficiency solar pumped lasers with low threshold power would be more promising than semiconductor lasers with large solar panel in space laser communication. Here we report a significant advance in solar-pumped laser threshold by pumping Nd:YAG rod with a grooved sidewall. Two-solar pumped laser setups are devised. In both cases, a Fresnel lens is used as the primary sunlight concentrator. Gold-plated conical cavity with a liquid light-guide lens is used as the secondary concentrator to further increase the solar energy concentration. In the first setup, solar pumping a 6mm diameter Nd:YAG rod, maximum laser power of 31.0W/m2 cw at 1064nm is produced, which is higher than the reported record, and the slope efficiency is 4.98% with the threshold power on the surface of Fresnel lens is 200 W. In the second setup, a 5 mm diameter laser rod output power is 29.8W/m2 with a slope efficiency of 4.3%. The threshold power of 102W is obtained, which is 49% lower than the former. Meanwhile, the theoretical calculating of the threshold power and slope efficiency of the solar-pumped laser has been established based on the rate-equation of a four-level system. The results of the finite element analysis by simulation software are verified in experiment. The optimization of the conical cavity by TraceProsoftware and the optimization of the laser resonator by LASCADare useful for the design of a miniaturization solar- pumped laser.

[Design and verification of Luo-Ye pump-based stress formation for cultivation of tissue-engineered blood vessel].

PubMed

Liao, Wen-Jun; Chen, Wan-Wen; Wen, Zhang; Wu, Yue-Heng; Li, Dong-Feng; Zhou, Jia-Hui; Zheng, Jian-Yi; Lin, Zhan-Yi

2016-06-20

To improve Luo-Ye pump-based stress-forming system and optimize the stimulating effect on smooth muscle cells during cultivation of tissue-engineered blood vessels (TEBV). A new Luo-Ye pump-based TEBV 3D culture system was developed by adding an air pump to the output of the bioreactor. A pressure guide wire was used to measure the stress at different points of the silicone tube inside the TEBV bio-reactor, and fitting curves of the stress changes over time was created using Origin 8.0 software. The TEBVs were constructed by seeding vascular smooth muscle cells (VSMCs) isolated from human umbilical artery on polyglycolic acid (PGA) and cultured under dynamic conditions with 40 mmHg resistance (improved group), dynamic conditions without resistance (control group) or static condition (static group) for 4 weeks. The harvested TEBVs were then examined with HE staining, masson staining, α-SMA immunohistochemical staining, and scanning and transmission electron microscopy with semi-quantitative analysis of collagen content and α-SMA expression. The measured stress values and the fitting curves showed that the stress stimuli from the Luo-Ye pump were enhanced by adding an air pump to the output of the bioreactor. Histological analysis revealed improved VSMC density, collagen content and α-SMA expression in the TEBVs constructed with the improved method as compared with those in the control and static groups. Adding an air pump to the Luo-Ye pump significantly enhances the stress stimulation in the TEBV 3-D culture system to promote the secretion function of VSMCs.

The Roles of IL-6, IL-10, and IL-1RA in Obesity and Insulin Resistance in African-Americans

PubMed Central

Doumatey, Ayo; Huang, Hanxia; Zhou, Jie; Chen, Guanjie; Shriner, Daniel; Adeyemo, Adebowale

2011-01-01

Objective: The aim of the study was to investigate the associations between IL-1 receptor antagonist (IL-1RA), IL-6, IL-10, measures of obesity, and insulin resistance in African-Americans. Research Design and Methods: Nondiabetic participants (n = 1025) of the Howard University Family Study were investigated for associations between serum IL (IL-1RA, IL-6, IL-10), measures of obesity, and insulin resistance, with adjustment for age and sex. Measures of obesity included body mass index, waist circumference, hip circumference, waist-to-hip ratio, and percent fat mass. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR). Data were analyzed with R statistical software using linear regression and likelihood ratio tests. Results: IL-1RA and IL-6 were associated with measures of obesity and insulin resistance, explaining 4–12.7% of the variance observed (P values < 0.001). IL-1RA was bimodally distributed and therefore was analyzed based on grouping those with low vs. high IL-1RA levels. High IL-1RA explained up to 20 and 12% of the variance in measures of obesity and HOMA-IR, respectively. Among the IL, only high IL-1RA improved the fit of models regressing HOMA-IR on measures of obesity. In contrast, all measures of obesity improved the fit of models regressing HOMA-IR on IL. IL-10 was not associated with obesity measures or HOMA-IR. Conclusions: High IL-1RA levels and obesity measures are associated with HOMA-IR in this population-based sample of African-Americans. The results suggest that obesity and increased levels of IL-1RA both contribute to the development of insulin resistance. PMID:21956416

Optimal hydraulic design of new-type shaft tubular pumping system

NASA Astrophysics Data System (ADS)

Zhu, H. G.; Zhang, R. T.; Zhou, J. R.

2012-11-01

Based on the characteristics of large flow rate, low-head, short annual operation time and high reliability of city flood-control pumping stations, a new-type shaft tubular pumping system featuring shaft suction box, siphon-type discharge passage with vacuum breaker as cutoff device was put forward, which possesses such advantages as simpler structure, reliable cutoff and higher energy performance. According to the design parameters of a city flood control pumping station, a numerical computation model was set up including shaft-type suction box, siphon-type discharge passage, pump impeller and guide vanes. By using commercial CFD software Fluent, RNG κ-epsilon turbulence model was adopted to close the three-dimensional time-averaged incompressible N-S equations. After completing optimal hydraulic design of shaft-type suction box, and keeping the parameters of total length, maximum width and outlet section unchanged, siphon-type discharge passages of three hump locations and three hump heights were designed and numerical analysis on the 9 hydraulic design schemes of pumping system were proceeded. The computational results show that the changing of hump locations and hump heights directly affects the internal flow patterns of discharge passages and hydraulic performances of the system, and when hump is located 3.66D from the inlet section and hump height is about 0.65D (D is the diameter of pump impeller), the new-type shaft tubular pumping system achieves better energy performances. A pumping system model test of the optimal designed scheme was carried out. The result shows that the highest pumping system efficiency reaches 75.96%, and when at design head of 1.15m the flow rate and system efficiency were 0.304m3/s and 63.10%, respectively. Thus, the validity of optimal design method was verified by the model test, and a solid foundation was laid for the application and extension of the new-type shaft tubular pumping system.

Quantitative measurement of zinc secretion from pancreatic islets with high temporal resolution using droplet-based microfluidics.

PubMed

Easley, Christopher J; Rocheleau, Jonathan V; Head, W Steven; Piston, David W

2009-11-01

We assayed glucose-stimulated insulin secretion (GSIS) from live, murine islets of Langerhans in microfluidic devices by the downstream formation of aqueous droplets. Zinc ions, which are cosecreted with insulin from beta-cells, were quantitatively measured from single islets with high temporal resolution using a fluorescent indicator, FluoZin-3. Real-time storage of secretions into droplets (volume of 0.470 +/- 0.009 nL) effectively preserves the temporal chemical information, allowing reconstruction of the secretory time record. The use of passive flow control within the device removes the need for syringe pumps, requiring only a single hand-held syringe. Under stimulatory glucose levels (11 mM), bursts of zinc as high as approximately 800 fg islet(-1) min(-1) were measured. Treatment with diazoxide effectively blocked zinc secretion, as expected. High temporal resolution reveals two major classes of oscillations in secreted zinc, with predominate periods at approximately 20-40 s and approximately 5-10 min. The more rapid oscillation periods match closely with those of intraislet calcium oscillations, while the slower oscillations are consistent with insulin pulses typically measured in bulk islet experiments or in the bloodstream. This droplet sampling technique should be widely applicable to time-resolved cellular secretion measurements, either in real-time or for postprocessing.

Quantitative measurement of zinc secretion from pancreatic islets with high temporal resolution using droplet-based microfluidics

PubMed Central

Easley, Christopher J.; Rocheleau, Jonathan V.; Head, W. Steven; Piston, David W.

2009-01-01

We assayed glucose-stimulated insulin secretion (GSIS) from live, murine islets of Langerhans in microfluidic devices by the downstream formation of aqueous droplets. Zinc ions, which are co-secreted with insulin from β-cells, were quantitatively measured from single islets with high temporal resolution using a fluorescent indicator, FluoZin-3. Real-time storage of secretions into droplets (volume of 0.470 ± 0.009 nL) effectively preserves the temporal chemical information, allowing reconstruction of the secretory time record. The use of passive flow control within the device removes the need for syringe pumps, requiring only a single handheld syringe. Under stimulatory glucose levels (11 mM), bursts of zinc as high as ~800 fg islet−1 min−1 were measured. Treatment with diazoxide effectively blocked zinc secretion, as expected. High temporal resolution reveals two major classes of oscillations in secreted zinc, with predominate periods at ~20-40 s and ~ 5-10 min. The more rapid oscillation periods match closely with those of intraislet calcium oscillations, while the slower oscillations are consistent with insulin pulses typically measured in bulk islet experiments or in the bloodstream. This droplet sampling technique should be widely applicable to time-resolved cellular secretion measurements, either in real-time or for post-processing. PMID:19874061

Diabetes and Ramadan: An Update On Use of Glycemic Therapies During Fasting

PubMed Central

Ahmed, Mohamed H.; Abdu, Tarig A. M.

2011-01-01

The fasting of Ramadan is observed by a large proportion of Muslims with diabetes. Recommendations for the management of diabetes during Ramadan were last published in 2005 by the American Diabetes Association. Several studies in this field have since been published, some addressing the use of new pharmacological agents in managing diabetes during Ramadan. The incritin memetics are potentially safe during Ramadan; the DPP4 inhibitors vildagliptin and sitagliptin provide an effective and safe therapeutic option, administered either alone or in combination with metformin or sulfonylureas. There are no published studies on the use of GLP-1 receptor agonists during Ramadan. Among the sulfonylureas, gliclazide MR (modified release) and glimepride can be safely used during Ramadan, but glibenclamide should be avoided due to the associated risk of hypoglycemia. In selected patients with type 1 and type 2 diabetes, the long-acting insulin analogues glargine and detemir, as well as the premixed insulin analogues, can be used with minimal risk of metabolic derangement or hypoglycemia; the risk is higher in type 1 diabetes. Insulin pumps can potentially empower patients with diabetes and enable safe fasting during the month of Ramadan. Further clinical trials are needed to evaluate the safety and efficacy of new antidiabetic agents and new diabetes-related technologies during Ramadan. PMID:21727749

Diabetes and Ramadan: an update on use of glycemic therapies during fasting.

PubMed

Ahmed, Mohamed H; Abdu, Tarig A M

2011-01-01

The fasting of Ramadan is observed by a large proportion of Muslims with diabetes. Recommendations for the management of diabetes during Ramadan were last published in 2005 by the American Diabetes Association. Several studies in this field have since been published, some addressing the use of new pharmacological agents in managing diabetes during Ramadan. The incritin memetics are potentially safe during Ramadan; the DPP4 inhibitors vildagliptin and sitagliptin provide an effective and safe therapeutic option, administered either alone or in combination with metformin or sulfonylureas. There are no published studies on the use of GLP-1 receptor agonists during Ramadan. Among the sulfonylureas, gliclazide MR (modified release) and glimepride can be safely used during Ramadan, but glibenclamide should be avoided due to the associated risk of hypoglycemia. In selected patients with type 1 and type 2 diabetes, the long-acting insulin analogues glargine and detemir, as well as the premixed insulin analogues, can be used with minimal risk of metabolic derangement or hypoglycemia; the risk is higher in type 1 diabetes. Insulin pumps can potentially empower patients with diabetes and enable safe fasting during the month of Ramadan. Further clinical trials are needed to evaluate the safety and efficacy of new antidiabetic agents and new diabetes-related technologies during Ramadan.

Unannounced Meals in the Artificial Pancreas: Detection Using Continuous Glucose Monitoring

PubMed Central

Herrero, Pau; Bondia, Jorge

2018-01-01

The artificial pancreas (AP) system is designed to regulate blood glucose in subjects with type 1 diabetes using a continuous glucose monitor informed controller that adjusts insulin infusion via an insulin pump. However, current AP developments are mainly hybrid closed-loop systems that include feed-forward actions triggered by the announcement of meals or exercise. The first step to fully closing the loop in the AP requires removing meal announcement, which is currently the most effective way to alleviate postprandial hyperglycemia due to the delay in insulin action. Here, a novel approach to meal detection in the AP is presented using a sliding window and computing the normalized cross-covariance between measured glucose and the forward difference of a disturbance term, estimated from an augmented minimal model using an Unscented Kalman Filter. Three different tunings were applied to the same meal detection algorithm: (1) a high sensitivity tuning, (2) a trade-off tuning that has a high amount of meals detected and a low amount of false positives (FP), and (3) a low FP tuning. For the three tunings sensitivities 99 ± 2%, 93 ± 5%, and 47 ± 12% were achieved, respectively. A sensitivity analysis was also performed and found that higher carbohydrate quantities and faster rates of glucose appearance result in favorable meal detection outcomes. PMID:29547553

Hypoglycaemia in diabetes mellitus: epidemiology and clinical implications.

PubMed

Frier, Brian M

2014-12-01

Hypoglycaemia is a frequent adverse effect of treatment of diabetes mellitus with insulin and sulphonylureas. Fear of hypoglycaemia alters self-management of diabetes mellitus and prevents optimal glycaemic control. Mild (self-treated) and severe (requiring help) hypoglycaemia episodes are more common in type 1 diabetes mellitus but people with insulin-treated type 2 diabetes mellitus are also exposed to frequent hypoglycaemic events, many of which occur during sleep. Hypoglycaemia can disrupt many everyday activities such as driving, work performance and leisure pursuits. In addition to accidents and physical injury, the morbidity of hypoglycaemia involves the cardiovascular and central nervous systems. Whereas coma and seizures are well-recognized neurological sequelae of hypoglycaemia, much interest is currently focused on the potential for hypoglycaemia to cause dangerous and life-threatening cardiac complications, such as arrhythmias and myocardial ischaemia, and whether recurrent severe hypoglycaemia can cause permanent cognitive impairment or promote cognitive decline and accelerate the onset of dementia in middle-aged and elderly people with diabetes mellitus. Prevention of hypoglycaemia is an important part of diabetes mellitus management and strategies include patient education, glucose monitoring, appropriate adjustment of diet and medications in relation to everyday circumstances including physical exercise, and the application of new technologies such as real-time continuous glucose monitoring, modified insulin pumps and the artificial pancreas.

Experimental and Numerical Analysis of Air Flow, Heat Transfer and Thermal Comfort in Buildings with Different Heating Systems

NASA Astrophysics Data System (ADS)

Sabanskis, A.; Virbulis, J.

2016-04-01

Monitoring of temperature, humidity and air flow velocity is performed in 5 experimental buildings with the inner size of 3×3×3 m3 located in Riga, Latvia. The buildings are equipped with different heating systems, such as an air-air heat pump, air-water heat pump, capillary heating mat on the ceiling and electric heater. Numerical simulation of air flow and heat transfer by convection, conduction and radiation is carried out using OpenFOAM software and compared with experimental data. Results are analysed regarding the temperature and air flow distribution as well as thermal comfort.

Project Baiterek: A Patient Access Program to Improve Clinical Outcomes and Quality of Life in Children with Type 1 Diabetes in Kazakhstan.

PubMed

Muratalina, Aigul; Smith-Palmer, Jayne; Nurbekova, Akmaral; Abduakhassova, Gulmira; Zhubandykova, Leila; Roze, Stéphane; Karamalis, Manolis; Shamshatova, Gulzhakhan; Demessinov, Adi; D'Agostino, Nicola Dunne; Lynch, Peter; Yedigarova, Larisa; Klots, Motty; Valentine, William; Welsh, John; Kaufman, Francine

2015-09-01

Diabetes is a key driver in the rise of noncommunicable diseases globally. It causes expensive and burdensome short- and long-term complications, with both an economic and social impact. In many countries, however, access to care and disease management in type 1 diabetes is suboptimal, increasing the risk for complications. In 2011, Project Baiterek was initiated as a collaborative effort between the Kazakhstan Ministry of Health, industry (Medtronic Plc), local physicians, and the Diabetes Association of the Republic of Kazakhstan to enhance patient access to continuous subcutaneous insulin infusion (CSII) therapy. It was the first countrywide project to provide equity and universal access to insulin pump therapy among children with type 1 diabetes, increasing pump use from zero to two-thirds of this population in less than 3 years. The project also involved instigating longitudinal data collection, and long-term clinical outcomes continue to be monitored. Here, we provide an overview of the clinical, quality-of-life, and economic outcomes to date associated with providing CSII therapy to children with type 1 diabetes in Kazakhstan. Initial clinical data show that CSII therapy improved clinical outcomes and quality of life for patients entered into the program and that CSII therapy was cost-effective relative to multiple daily injection therapy. The positive outcomes of Project Baiterek provide a template for similar patient access programs in other settings, and its framework could be adapted to initiatives to change health care infrastructures and standards of care for other noncommunicable diseases. Copyright © 2015. Published by Elsevier Inc.

Effects of performing morning versus afternoon exercise on glycemic control and hypoglycemia frequency in type 1 diabetes patients on sensor-augmented insulin pump therapy.

PubMed

Gomez, Ana Maria; Gomez, Claudia; Aschner, Pablo; Veloza, Angelica; Muñoz, Oscar; Rubio, Claudia; Vallejo, Santiago

2015-05-01

Although physical exercise (PE) is recommended for individuals with type 1 diabetes (DM1), participation in exercise is challenging because it increases the risk of severe hypoglycemia and the available therapeutic options to prevent it frequently result in hyperglycemia. There is no clear recommendation about the best timing for exercise. The aim of this study was to compare the risk of hypoglycemia after morning or afternoon exercise sessions up to 36 hours postworkout. This randomized crossover study enrolled subjects with DM1, older than 18 years of age, on sensor-augmented insulin pump (SAP) therapy. Participants underwent 2 moderate-intensity exercise sessions; 1 in the morning and 1 in the afternoon, separated by a 7 to 14 day wash-out period. Continuous glucose monitoring (CGM) data were collected 24 hours before, during and 36 hours after each session. Thirty-five subjects (mean age 30.31 ± 12.66 years) participated in the study. The rate of hypoglycemia was significantly lower following morning versus afternoon exercise sessions (5.6 vs 10.7 events per patient, incidence rate ratio, 0.52; 95% CI, 0.43-0.63; P < .0001). Most hypoglycemic events occurred 15-24 hours after the session. On days following morning exercise sessions, there were 20% more CGM readings in near-euglycemic range (70-200 mg/dL) than on days prior to morning exercise (P = .003). Morning exercise confers a lower risk of late-onset hypoglycemia than afternoon exercise and improves metabolic control on the subsequent day. © 2015 Diabetes Technology Society.

Nocturnal hypoglycaemia in type 1 diabetes--consequences and assessment.

PubMed

DeVries, J Hans; Wentholt, Iris M E; Masurel, Nathalie; Mantel, Itske; Poscia, Alessandro; Maran, Alberto; Heine, Robert J

2004-01-01

Hypoglycaemia is inevitable when striving for low HbA1c values. Nocturnal hypoglycaemia often occurs without symptoms, but results in diminished next day well-being and hypoglycaemia unawareness. Frequency of nocturnal hypoglycaemia was first assessed in research ward settings, but suffered from insufficient glucose sampling frequency. This may have resulted in overestimation of the duration of hypoglycaemic episodes. The advent of the first continuous glucose sensor, the needle-type MedtronicMiniMed Continuous Glucose Measurement System, revolutionized the assessment of glucose values. However, on scrutiny, the first version of this sensor showed a drift into the hypoglycaemic area and delayed recovery from hypoglycaemia. Using the microdialysis-based GlucoDay system, our group reported a lower frequency of nocturnal hypoglycaemia in type 1 diabetes patients using an insulin pump, than that expected from the existing literature. Today, more than 80 years after the introduction of insulin for the treatment of type 1 diabetes, the associated frequency of nocturnal hypoglycaemia still awaits its definitive assessment. Copyright 2004 John Wiley & Sons, Ltd.

Current trends in the monitoring and treatment of diabetic retinopathy in young adults.

PubMed

Raczyńska, Dorota; Zorena, Katarzyna; Urban, Beata; Zalewski, Dominik; Skorek, Andrzej; Malukiewicz, Grażyna; Sikorski, Bartosz L

2014-01-01

The diagnosis and treatment of diabetic retinopathy (DR) in young adults have significantly improved in recent years. Research methods have widened significantly, for example, by introducing spectral optical tomography of the eye. Invasive diagnostics, for example, fluorescein angiography, are done less frequently. The early introduction of an insulin pump to improve the administration of insulin is likely to delay the development of diabetic retinopathy, which is particularly important for young patients with type 1 diabetes mellitus (T1DM). The first years of diabetes occurring during childhood and youth are the most appropriate to introduce proper therapeutic intervention before any irreversible changes in the eyes appear. The treatment of DR includes increased metabolic control, laserotherapy, pharmacological treatment (antiangiogenic and anti-inflammatory treatment, enzymatic vitreolysis, and intravitreal injections), and surgery. This paper summarizes the up-to-date developments in the diagnostics and treatment of DR. In the literature search, authors used online databases, PubMed, and clinitrials.gov and browsed through individual ophthalmology journals, books, and leading pharmaceutical company websites.

Glucagon in the artificial pancreas: supply and marketing challenges.

PubMed

Rylander, Dick

2015-01-01

The use of glucagon, in conjunction with insulin, in a dual chamber pump (artificial pancreas, AP) is a working goal for multiple companies and researchers. However, capital investment to create, operate, and maintain facilities with sufficient scale to produce enough glucagon to treat millions of patients, at a level of profit that makes it feasible, will be substantial. It can be assumed that the marketplace will expect the daily cost of glucagon (to the consumer) to be similar to the daily cost of insulin. After one subtracts wholesaler and pharmacy markup, there may be very few dollars remaining for the drug company to cover profit, capital expenditures, marketing, burden, and other costs. Without the potential for adequate margins, manufacturers may not be willing to take the risk. Assuming that the projections discussed in this article are in the right ballpark, advance planning for the supply for glucagon needs to start today and not wait for the AP to come to market. © 2014 Diabetes Technology Society.

Adaptive control of artificial pancreas systems - a review.

PubMed

Turksoy, Kamuran; Cinar, Ali

2014-01-01

Artificial pancreas (AP) systems offer an important improvement in regulating blood glucose concentration for patients with type 1 diabetes, compared to current approaches. AP consists of sensors, control algorithms and an insulin pump. Different AP control algorithms such as proportional-integral-derivative, model-predictive control, adaptive control, and fuzzy logic control have been investigated in simulation and clinical studies in the past three decades. The variability over time and complexity of the dynamics of blood glucose concentration, unsteady disturbances such as meals, time-varying delays on measurements and insulin infusion, and noisy data from sensors create a challenging system to AP. Adaptive control is a powerful control technique that can deal with such challenges. In this paper, a review of adaptive control techniques for blood glucose regulation with an AP system is presented. The investigations and advances in technology produced impressive results, but there is still a need for a reliable AP system that is both commercially viable and appealing to patients with type 1 diabetes.

Analysis of laser pumping and thermal effects based on element analysis

NASA Astrophysics Data System (ADS)

Cui, Li; Liu, Zhijia; Zhang, Yizhuo; Han, Juan

2018-03-01

Thermal effect is a plateau that limits the output of high-power, high beam quality laser, and thermal effects become worse with the increase of pump power. We can reduce the effects caused by thermal effects from pumping, laser medium shape, cooling method and other aspects. In this article, by using finite element analysis software, the thermal effects between Nd:Glass and Nd:YAG laser crystal was analyzed and compared. The causes of generation for thermal effects, and factors that influence the distribution in laser medium were analyzed, including the light source, the laser medium shape and the working mode. Nd:Glass is more suitable for low repetition frequency, high energy pulsed laser output, due to its large size, line width and so on, and Nd:YAG is more suitable for continue or high repetition rate laser output, due to its higher thermal conductivity.

Performance analysis of underwater pump for water-air dual-use engine

NASA Astrophysics Data System (ADS)

Xia, Jun; Wang, Yun; Chen, Yu

2017-10-01

To make water-air dual-use engine work both in air and under water, the compressor of the engine should not only meet the requirements of air flight, but also must have the ability to work underwater. To verify the performance of the compressor when the water-air dual-use engine underwater propulsion mode, the underwater pumping water model of the air compressor is simulated by commercial CFD software, and the flow field analysis is carried out. The results show that conventional air compressors have a certain ability to work in the water environment, however, the blade has a great influence on the flow, and the compressor structure also affects the pump performance. Compressor can initially take into account the two modes of water and air. In order to obtain better performance, the structure of the compressor needs further improvement and optimization.

Bubble measuring instrument and method

NASA Technical Reports Server (NTRS)

Magari, Patrick J. (Inventor); Kline-Schoder, Robert (Inventor)

2003-01-01

Method and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer, respectively. The image transducer frequency is much higher than the pump transducer frequency. The relatively low-frequency pump signal is used to excite bubbles to resonate at a frequency related to their diameter. The image transducer is operated in a pulse-echo mode at a controllable repetition rate that transmits bursts of high-frequency ultrasonic signal to the measurement volume in which bubbles may be detected and then receives the echo. From the echo or received signal, a beat signal related to the repetition rate may be extracted and used to indicate the presence or absence of a resonant bubble. In a preferred embodiment, software control maintains the beat signal at a preselected frequency while varying the pump transducer frequency to excite bubbles of different diameters to resonate depending on the range of bubble diameters selected for investigation.

European Regional Climate Zone Modeling of a Commercial Absorption Heat Pump Hot Water Heater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Vishaldeep; Shen, Bo; Keinath, Chris

2017-01-01

High efficiency gas-burning hot water heating takes advantage of a condensing heat exchanger to deliver improved combustion efficiency over a standard non-condensing configuration. The water heating is always lower than the gas heating value. In contrast, Gas Absorption Heat Pump (GAHP) hot water heating combines the efficiency of gas burning with the performance increase from a heat pump to offer significant gas energy savings. An ammonia-water system also has the advantage of zero Ozone Depletion Potential and low Global Warming Potential. In comparison with air source electric heat pumps, the absorption system can maintain higher coefficients of performance in coldermore » climates. In this work, a GAHP commercial water heating system was compared to a condensing gas storage system for a range of locations and climate zones across Europe. The thermodynamic performance map of a single effect ammonia-water absorption system was used in a building energy modeling software that could also incorporate the changing ambient air temperature and water mains temperature for a specific location, as well as a full-service restaurant water draw pattern.« less

Bubble Measuring Instrument and Method

NASA Technical Reports Server (NTRS)

Kline-Schoder, Robert (Inventor); Magari, Patrick J. (Inventor)

2002-01-01

Method and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer. respectively. The image transducer frequency is much higher than the pump transducer frequency. The relatively low-frequency pump signal is used to excite bubbles to resonate at a frequency related to their diameter. The image transducer is operated in a pulse-echo mode at a controllable repetition rate that transmits bursts of high-frequency ultrasonic signal to the measurement volume in which bubbles may be detected and then receives the echo. From the echo or received signal, a beat signal related to the repetition rate may be extracted and used to indicate the presence or absence of a resonant bubble. In a preferred embodiment, software control maintains the beat signal at a preselected frequency while varying the pump transducer frequency to excite bubbles of different diameters to resonate depending on the range of bubble diameters selected for investigation.

Output characteristics of a series three-port axial piston pump

NASA Astrophysics Data System (ADS)

Zhang, Xiaogang; Quan, Long; Yang, Yang; Wang, Chengbin; Yao, Liwei

2012-05-01

Driving a hydraulic cylinder directly by a closed-loop hydraulic pump is currently a key research area in the field of electro-hydraulic control technology, and it is the most direct means to improve the energy efficiency of an electro-hydraulic control system. So far, this technology has been well applied to the pump-controlled symmetric hydraulic cylinder. However, for the differential cylinder that is widely used in hydraulic technology, satisfactory results have not yet been achieved, due to the asymmetric flow constraint. Therefore, based on the principle of the asymmetric valve controlled asymmetric cylinder in valve controlled cylinder technology, an innovative idea for an asymmetric pump controlled asymmetric cylinder is put forward to address this problem. The scheme proposes to transform the oil suction window of the existing axial piston pump into two series windows. When in use, one window is connected to the rod chamber of the hydraulic cylinder and the other is linked with a low-pressure oil tank. This allows the differential cylinders to be directly controlled by changing the displacement or rotation speed of the pumps. Compared with the loop principle of offsetting the area difference of the differential cylinder through hydraulic valve using existing technology, this method may simplify the circuits and increase the energy efficiency of the system. With the software SimulationX, a hydraulic pump simulation model is set up, which examines the movement characteristics of an individual piston and the compressibility of oil, as well as the flow distribution area as it changes with the rotation angle. The pump structure parameters, especially the size of the unloading groove of the valve plate, are determined through digital simulation. All of the components of the series arranged three distribution-window axial piston pump are designed, based on the simulation analysis of the flow pulse characteristics of the pump, and then the prototype pump is made. The basic characteristics, such as the pressure, flow and noise of the pumps under different rotation speeds, are measured on the test bench. The test results verify the correctness of the principle. The proposed research lays a theoretical foundation for the further development of a new pump-controlled cylinder system.

A Practical Application of Microcomputers to Control an Active Solar System.

ERIC Educational Resources Information Center

Goldman, David S.; Warren, William

1984-01-01

Describes the design and implementation of a microcomputer-based model active solar heating system. Includes discussions of: (1) the active solar components (solar collector, heat exchanger, pump, and fan necessary to provide forced air heating); (2) software components; and (3) hardware components (in the form of sensors and actuators). (JN)

Implementation guide for turbidity threshold sampling: principles, procedures, and analysis

Treesearch

Jack Lewis; Rand Eads

2009-01-01

Turbidity Threshold Sampling uses real-time turbidity and river stage information to automatically collect water quality samples for estimating suspended sediment loads. The system uses a programmable data logger in conjunction with a stage measurement device, a turbidity sensor, and a pumping sampler. Specialized software enables the user to control the sampling...

Automated Cryocooler Monitor and Control System Software

NASA Technical Reports Server (NTRS)

Britchcliffe, Michael J.; Conroy, Bruce L.; Anderson, Paul E.; Wilson, Ahmad

2011-01-01

This software is used in an automated cryogenic control system developed to monitor and control the operation of small-scale cryocoolers. The system was designed to automate the cryogenically cooled low-noise amplifier system described in "Automated Cryocooler Monitor and Control System" (NPO-47246), NASA Tech Briefs, Vol. 35, No. 5 (May 2011), page 7a. The software contains algorithms necessary to convert non-linear output voltages from the cryogenic diode-type thermometers and vacuum pressure and helium pressure sensors, to temperature and pressure units. The control function algorithms use the monitor data to control the cooler power, vacuum solenoid, vacuum pump, and electrical warm-up heaters. The control algorithms are based on a rule-based system that activates the required device based on the operating mode. The external interface is Web-based. It acts as a Web server, providing pages for monitor, control, and configuration. No client software from the external user is required.

Heterodyne-detected dispersed vibrational echo spectroscopy.

PubMed

Jones, Kevin C; Ganim, Ziad; Tokmakoff, Andrei

2009-12-24

We develop heterodyned dispersed vibrational echo spectroscopy (HDVE) and demonstrate the new capabilities in biophysical applications. HDVE is a robust ultrafast technique that provides a characterization of the real and imaginary components of third-order nonlinear signals with high sensitivity and single-laser-shot capability and can be used to extract dispersed pump-probe and dispersed vibrational echo spectra. Four methods for acquiring HDVE phase and amplitude spectra were compared: Fourier transform spectral interferometry, a new phase modulation spectral interferometry technique, and combination schemes. These extraction techniques were demonstrated in the context of protein amide I spectroscopy. Experimental HDVE and heterodyned free induction decay amide I spectra were explicitly compared to conventional dispersed pump-probe, dispersed vibrational echo, and absorption spectra. The new capabilities of HDVE were demonstrated by acquiring single-shot spectra and melting curves of ubiquitin and concentration-dependent spectra of insulin suitable for extracting the binding constant for dimerization. The introduced techniques will prove particularly useful in transient experiments, studying irreversible reactions, and micromolar concentration studies of small proteins.

Efficacy of an Overnight Predictive Low-Glucose Suspend System in Relation to Hypoglycemia Risk Factors in Youth and Adults With Type 1 Diabetes.

PubMed

Calhoun, Peter M; Buckingham, Bruce A; Maahs, David M; Hramiak, Irene; Wilson, Darrell M; Aye, Tandy; Clinton, Paula; Chase, Peter; Messer, Laurel; Kollman, Craig; Beck, Roy W; Lum, John

2016-11-01

We developed a system to suspend insulin pump delivery overnight when the glucose trend predicts hypoglycemia. This predictive low-glucose suspend (PLGS) system substantially reduces nocturnal hypoglycemia without an increase in morning ketosis. Evaluation of hypoglycemia risk factors that could potentially influence the efficacy of the system remains critical for understanding possible problems with the system and identifying patients that may have the greatest benefit when using the system. The at-home randomized trial consisted of 127 study participants with hemoglobin A1c (A1C) of ≤8.5% (mmol/mol) for patients aged 4-14 years and ≤8.0% for patient aged 15-45 years. Factors assessed included age, gender, A1C, diabetes duration, daily percentage basal insulin, total daily dose of insulin (units/kg-day), bedtime BG, bedtime snack, insulin on board, continuous glucose monitor (CGM) rate of change (ROC), day of the week, time system activated, daytime exercise intensity, and daytime CGM-measured hypoglycemia. The PLGS system was effective in preventing hypoglycemia for each factor subgroup. There was no evidence that the PLGS system was more or less effective in preventing hypoglycemia in any one subgroup compared with the other subgroups based on that factor. In addition, the effect of the system on overnight hyperglycemia did not differ in subgroups. The PLGS system tested in this study effectively reduced hypoglycemia without a meaningful increase in hyperglycemia across a variety of factors. © 2016 Diabetes Technology Society.

Development of Stable Liquid Glucagon Formulations for Use in Artificial Pancreas

PubMed Central

Li, Ming; Krasner, Alan; De Souza, Errol

2014-01-01

Background: A promising approach to treat diabetes is the development of fully automated artificial/bionic pancreas systems that use both insulin and glucagon to maintain euglycemia. A physically and chemically stable liquid formulation of glucagon does not currently exist. Our goal is to develop a glucagon formulation that is stable as a clear and gel-free solution, free of fibrils and that has the requisite long-term shelf life for storage in the supply chain, short-term stability for at least 7 days at 37°C, and pump compatibility for use in a bihormonal pump. Methods: We report the development of two distinct families of stable liquid glucagon formulations which utilize surfactant or surfactant-like excipients (LMPC and DDM) to “immobilize” the glucagon in solution potentially through the formation of micelles and prevention of interaction between glucagon molecules. Results: Data are presented that demonstrate long-term physical and chemical stability (~2 years) at 5°C, short-term stability (up to 1 month) under accelerated 37°C testing conditions, pump compatibility for up to 9 days, and adequate glucose responses in dogs and diabetic swine. Conclusions: These stable glucagon formulations show utility and promise for further development in artificial pancreas systems. PMID:25352634

Cavitation in centrifugal pump with rotating walls of axial inlet device

NASA Astrophysics Data System (ADS)

Moloshnyi, O.; Sotnyk, M.

2017-08-01

The article deals with the analysis of cavitation processes in the flowing part of the double entry centrifugal pump. The analysis is conducted using numerical modeling of the centrifugal pump operating process in the software environment ANSYS CFX. Two models of the axial inlet device is researched. It is shaped by a cylindrical section and diffuser section in front of the impeller, which includes fairing. The walls of the axial inlet device rotate with the same speed as the pump rotor. The numerical experiment is conducted under the condition of the flow rate change and absolute pressure at the inlet. The analysis shows that the pump has the average statistical cavitation performance. The occurrence of the cavitation in the axial inlet device is after narrowing the cross-section of flow channel and at the beginning of the diffuser section. Additional sudden expansion at the outlet of the axial inlet diffuser section does not affect the cavitation characteristics of the impeller, however, improves cavitation characteristics of the axial inlet device. For considered geometric parameters of the axial inlet device the cavitation in the impeller begins earlier than in the axial inlet device. That is, the considered design of the axial inlet device will not be subjected to destruction at the ensuring operation without cavitation in the impeller.

Optimization on the impeller of a low-specific-speed centrifugal pump for hydraulic performance improvement

NASA Astrophysics Data System (ADS)

Pei, Ji; Wang, Wenjie; Yuan, Shouqi; Zhang, Jinfeng

2016-09-01

In order to widen the high-efficiency operating range of a low-specific-speed centrifugal pump, an optimization process for considering efficiencies under 1.0 Q d and 1.4 Q d is proposed. Three parameters, namely, the blade outlet width b 2, blade outlet angle β 2, and blade wrap angle φ, are selected as design variables. Impellers are generated using the optimal Latin hypercube sampling method. The pump efficiencies are calculated using the software CFX 14.5 at two operating points selected as objectives. Surrogate models are also constructed to analyze the relationship between the objectives and the design variables. Finally, the particle swarm optimization algorithm is applied to calculate the surrogate model to determine the best combination of the impeller parameters. The results show that the performance curve predicted by numerical simulation has a good agreement with the experimental results. Compared with the efficiencies of the original impeller, the hydraulic efficiencies of the optimized impeller are increased by 4.18% and 0.62% under 1.0 Q d and 1.4Qd, respectively. The comparison of inner flow between the original pump and optimized one illustrates the improvement of performance. The optimization process can provide a useful reference on performance improvement of other pumps, even on reduction of pressure fluctuations.

A cohort of children with type 1 diabetes in Greece: predictors of direct costs of care.

PubMed

Karachaliou, Feneli; Athanasakis, Konstantinos; Tsentidis, Charalabos; Soldatou, Alexandra; Simatos, George; Kyriopoulos, John; Michalakos, Stefanos; Karavanaki, Kyriaki

2017-08-01

To examine the predictors of direct costs of pediatric type 1 diabetes (T1D) in a hospital-based outpatient clinic in Greece. The outpatient records of 89 children and adolescents (mean age: 12.05 ± 5.15 y) with T1D followed in the Second Department of Pediatrics, University of Athens Medical School, were analyzed. The mean ± SD diabetes duration was 4.9 ± 3.88 y (range: 0.25-17) and glycated hemoglobin (HbA1c) was 8.2 ± 1.09% (66 ± 11.9 mmol/mol). A total of 80% of patients were on multiple daily injections regimen, 10% on pump therapy, and 10% on conventional regimen. Total direct costs per patient-year (ppy) were estimated at €2.712 [95% confidence interval (CI): 2.468-2.956]. Supply costs accounted for 73.7% of total costs and were the highest for pump therapy (P < .001). Multivariate linear regression analysis showed that costs were significantly higher for children (1) on multiple daily injections or pump therapy (r = 0.364, P < .001), (2) of older age (r = 0.25, P < .001) and (3) higher daily insulin dose (r = 0.46, P < .001). Patients on pump therapy had significantly higher costs €5.538 (95%CI 4480-6597) compared with patients on multiple daily injections €2.447 (95% CI 2320-2574) and conventional regimen €1.978.5 (95%CI 1682-2275) (P = .0001). Patients on pump therapy had better glycemic control compared with all other patients [HbA1c (mean ± SD): 7.2% ± 1.0 vs 8.3% ±1.5, P = .039]. The total T1D cost in this cohort of Greek children was €2712 ppy. The main factor that predicted direct cost was the use of pump. However, pump therapy was associated with better glycaemic control, which may decrease the risk of total long-term diabetes care cost. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Development of a miniature motor-driven pulsatile LVAD driven by a fuzzy controller.

PubMed

Okamoto, Eiji; Makino, Tsutomu; Tanaka, Shuji; Yasuda, Takahiko; Akasaka, Yuta; Tani, Makiko; Inoue, Yusuke; Mitoh, Ayumu; Mitamura, Yoshinori

2007-01-01

We have been developing a small, lightweight motor-driven pulsatile left ventricular assist device (LVAD) with a ball screw. The motor-driven LVAD consists of a brushless DC motor and a ball screw. The attractive magnetic force between Nd-Fe-B magnets (with a diameter of 5 mm and a thickness of 1.5 mm) mounted in holes in a silicone rubber sheet (thickness 2 mm) and an iron plate adhered onto the a diaphragm of the blood pump can provide optimum active blood filling during the pump filling phase. The LVAD has a stroke volume of 55 ml and an overall volume of 285 ml; it weighs 360 g. The controller mainly consists of a fuzzy logic position and velocity controller to apply doctors' and engineers' knowledge to control the LVAD. Each unit of the controller consists of a functionally independent program module for easy improvement of the controller's performance. The LVAD was evaluated in in vitro experiments using a mock circulation. A maximum pump outflow of 5.1 l/min was obtained at a drive rate of 95 bpm against an afterload of 95 mmHg, and active filling using the attractive magnetic force provided a pump output of 3.6 l/min at a drive rate of 75 bpm under a preload of 0 mmHg. The operating efficiency of the LVAD was measured at between 8% and 10.5%. While the LVAD can provide adequate pump outflow for cardiac assistance, further upgrading of the software and improvement of the blood pump are required to improve pump performance and efficiency.