21 CFR 870.5550 - External transcutaneous cardiac pacemaker (noninvasive).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External transcutaneous cardiac pacemaker... § 870.5550 External transcutaneous cardiac pacemaker (noninvasive). (a) Identification. An external transcutaneous cardiac pacemaker (noninvasive) is a device used to supply a periodic electrical pulse intended to...

21 CFR 870.5550 - External transcutaneous cardiac pacemaker (noninvasive).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false External transcutaneous cardiac pacemaker... § 870.5550 External transcutaneous cardiac pacemaker (noninvasive). (a) Identification. An external transcutaneous cardiac pacemaker (noninvasive) is a device used to supply a periodic electrical pulse intended to...

21 CFR 870.5550 - External transcutaneous cardiac pacemaker (noninvasive).

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false External transcutaneous cardiac pacemaker... § 870.5550 External transcutaneous cardiac pacemaker (noninvasive). (a) Identification. An external transcutaneous cardiac pacemaker (noninvasive) is a device used to supply a periodic electrical pulse intended to...

21 CFR 870.5550 - External transcutaneous cardiac pacemaker (noninvasive).

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false External transcutaneous cardiac pacemaker... § 870.5550 External transcutaneous cardiac pacemaker (noninvasive). (a) Identification. An external transcutaneous cardiac pacemaker (noninvasive) is a device used to supply a periodic electrical pulse intended to...

21 CFR 870.5550 - External transcutaneous cardiac pacemaker (noninvasive).

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false External transcutaneous cardiac pacemaker... § 870.5550 External transcutaneous cardiac pacemaker (noninvasive). (a) Identification. An external transcutaneous cardiac pacemaker (noninvasive) is a device used to supply a periodic electrical pulse intended to...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Transcutaneous electrical nerve stimulator for... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Transcutaneous electrical nerve stimulator for...

Permeation of antigen protein-conjugated nanoparticles and live bacteria through microneedle-treated mouse skin

PubMed Central

Kumar, Amit; Li, Xinran; Sandoval, Michael A; Rodriguez, B Leticia; Sloat, Brian R; Cui, Zhengrong

2011-01-01

Background: The present study was designed to evaluate the extent to which pretreatment with microneedles can enhance skin permeation of nanoparticles in vitro and in vivo. Permeation of live bacteria, which are physically nanoparticles or microparticles, through mouse skin pretreated with microneedles was also studied to evaluate the potential risk of microbial infection. Methods and results: It was found that pretreatment of mouse skin with microneedles allowed permeation of solid lipid nanoparticles, size 230 nm, with ovalbumin conjugated on their surface. Transcutaneous immunization in a mouse skin area pretreated with microneedles with ovalbumin nanoparticles induced a stronger antiovalbumin antibody response than using ovalbumin alone. The dose of ovalbumin antigen determined whether microneedle-mediated transcutaneous immunization with ovalbumin nanoparticles induced a stronger immune response than subcutaneous injection of the same ovalbumin nanoparticles. Microneedle treatment permitted skin permeation of live Escherichia coli, but the extent of the permeation was not greater than that enabled by hypodermic injection. Conclusion: Transcutaneous immunization on a microneedle-treated skin area with antigens carried by nanoparticles can potentially induce a strong immune response, and the risk of bacterial infection associated with microneedle treatment is no greater than that with a hypodermic injection. PMID:21753877

An Implantable Wireless Neural Interface for Recording Cortical Circuit Dynamics in Moving Primates

PubMed Central

Borton, David A.; Yin, Ming; Aceros, Juan; Nurmikko, Arto

2013-01-01

Objective Neural interface technology suitable for clinical translation has the potential to significantly impact the lives of amputees, spinal cord injury victims, and those living with severe neuromotor disease. Such systems must be chronically safe, durable, and effective. Approach We have designed and implemented a neural interface microsystem, housed in a compact, subcutaneous, and hermetically sealed titanium enclosure. The implanted device interfaces the brain with a 510k-approved, 100-element silicon-based MEA via a custom hermetic feedthrough design. Full spectrum neural signals were amplified (0.1Hz to 7.8kHz, ×200 gain) and multiplexed by a custom application specific integrated circuit, digitized, and then packaged for transmission. The neural data (24 Mbps) was transmitted by a wireless data link carried on an frequency shift key modulated signal at 3.2GHz and 3.8GHz to a receiver 1 meter away by design as a point-to-point communication link for human clinical use. The system was powered by an embedded medical grade rechargeable Li-ion battery for 7-hour continuous operation between recharge via an inductive transcutaneous wireless power link at 2MHz. Main results Device verification and early validation was performed in both swine and non-human primate freely-moving animal models and showed that the wireless implant was electrically stable, effective in capturing and delivering broadband neural data, and safe for over one year of testing. In addition, we have used the multichannel data from these mobile animal models to demonstrate the ability to decode neural population dynamics associated with motor activity. Significance We have developed an implanted wireless broadband neural recording device evaluated in non-human primate and swine. The use of this new implantable neural interface technology can provide insight on how to advance human neuroprostheses beyond the present early clinical trials. Further, such tools enable mobile patient use, have the potential for wider diagnosis of neurological conditions, and will advance brain research. PMID:23428937

An implantable wireless neural interface for recording cortical circuit dynamics in moving primates

NASA Astrophysics Data System (ADS)

Borton, David A.; Yin, Ming; Aceros, Juan; Nurmikko, Arto

2013-04-01

Objective. Neural interface technology suitable for clinical translation has the potential to significantly impact the lives of amputees, spinal cord injury victims and those living with severe neuromotor disease. Such systems must be chronically safe, durable and effective. Approach. We have designed and implemented a neural interface microsystem, housed in a compact, subcutaneous and hermetically sealed titanium enclosure. The implanted device interfaces the brain with a 510k-approved, 100-element silicon-based microelectrode array via a custom hermetic feedthrough design. Full spectrum neural signals were amplified (0.1 Hz to 7.8 kHz, 200× gain) and multiplexed by a custom application specific integrated circuit, digitized and then packaged for transmission. The neural data (24 Mbps) were transmitted by a wireless data link carried on a frequency-shift-key-modulated signal at 3.2 and 3.8 GHz to a receiver 1 m away by design as a point-to-point communication link for human clinical use. The system was powered by an embedded medical grade rechargeable Li-ion battery for 7 h continuous operation between recharge via an inductive transcutaneous wireless power link at 2 MHz. Main results. Device verification and early validation were performed in both swine and non-human primate freely-moving animal models and showed that the wireless implant was electrically stable, effective in capturing and delivering broadband neural data, and safe for over one year of testing. In addition, we have used the multichannel data from these mobile animal models to demonstrate the ability to decode neural population dynamics associated with motor activity. Significance. We have developed an implanted wireless broadband neural recording device evaluated in non-human primate and swine. The use of this new implantable neural interface technology can provide insight into how to advance human neuroprostheses beyond the present early clinical trials. Further, such tools enable mobile patient use, have the potential for wider diagnosis of neurological conditions and will advance brain research.

Transcutaneous Bilirubin Nomogram for Healthy Term and Late Preterm Neonates in First 96 Hours of Life.

PubMed

Thakkar, Pareshkumar; Chavda, Hardas; Doshi, Vikas

2017-05-15

To develop nomogram of Transcutaneous Bilirubin among healthy term and late-preterm neonates during first 96 hours of age. Longitudinal observational study. Neonatal unit of a tertiary care Hospital of Central Gujarat, India. 1075 healthy term and late preterm neonates (≥35weeks). Six-hourly transcutaneous bilirubin was obtained from birth to 96 hour of life using Drager JM 103 Transcutaneous Bilirubinometer. Main outcome measures: Nomogram of Transcutaneous Bilirubin with percentile values was obtained, rate of rise of bilirubin was calculated and predictive ability of normative data was analyzed for subsequent need of phototherapy. The age-specific percentile curves and nomogram were developed from the transcutaneous bilirubin readings of 1,010 neonates. Rate of rise in first 12 hour was 0.2 mg/dL and was 0.17 mg/dL in 12 to 24 hour of life which decreased on second day of life. Neonates who required phototherapy had consistently higher readings of transcutaneous bilirubin and also higher rate of rise in first 48 hrs. Neonates whose transcutaneous bilirubin is above the 50th percentile should be monitored for the development of significant hyperbilirubinemia.

Comparison of Transcutaneous Bilirubin Measurement With Total Serum Bilirubin Levels in Preterm Neonates Receiving Phototherapy.

PubMed

Pendse, Amruta; Jasani, Bonny; Nanavati, Ruchi; Kabra, Nandkishor

2017-08-15

To compare transcutaneous bilirubin with total serum bilirubin in preterm neonates after initiation of phototherapy. Jaundice was assessed in 30 preterm neonates with transcutaneous bilirubin and total serum bilirubin before initiation of phototherapy and at 12 hr after initiation of phototherapy. A photo-occlusive patch was applied over the sternum. Transcutaneous bilirubin has a good correlation with total serum bilirubin after initiation of phototherapy. (r=0.918, P<0.001). Transcutaneous bilirubin at 28-32 weeks of gestation (r = 0.97) was better correlated with total serum bilirubin than those at 32-37 weeks (r =0.88). The correlation was better for neonates <72 hours old (r = 0.96) than those >72 hours of age (r = 0.82). Transcutaneous bilirubin correlates significantly with total serum bilirubin at the patched sternal site after initiation of phototherapy in preterm neonates.

Cutaneous electrical stimulation treatment in unresolved facial nerve paralysis: an exploratory study.

PubMed

Hyvärinen, Antti; Tarkka, Ina M; Mervaala, Esa; Pääkkönen, Ari; Valtonen, Hannu; Nuutinen, Juhani

2008-12-01

The purpose of this study was to assess clinical and neurophysiological changes after 6 mos of transcutaneous electrical stimulation in patients with unresolved facial nerve paralysis. A pilot case series of 10 consecutive patients with chronic facial nerve paralysis either of idiopathic origin or because of herpes zoster oticus participated in this open study. All patients received below sensory threshold transcutaneous electrical stimulation for 6 mos for their facial nerve paralysis. The intervention consisted of gradually increasing the duration of electrical stimulation of three sites on the affected area for up to 6 hrs/day. Assessments of the facial nerve function were performed using the House-Brackmann clinical scale and neurophysiological measurements of compound motor action potential distal latencies on the affected and nonaffected sides. Patients were tested before and after the intervention. A significant improvement was observed in the facial nerve upper branch compound motor action potential distal latency on the affected side in all patients. An improvement of one grade in House-Brackmann scale was observed and some patients also reported subjective improvement. Transcutaneous electrical stimulation treatment may have a positive effect on unresolved facial nerve paralysis. This study illustrates a possibly effective treatment option for patients with the chronic facial paresis with no other expectations of recovery.

A flexible transcutaneous oxygen sensor using polymer membranes.

PubMed

Kudo, Hiroyuki; Iguchi, Shigehito; Yamada, Takua; Kawase, Tatsuya; Saito, Hirokazu; Otsuka, Kimio; Mitsubayashi, Kohji

2007-02-01

A wearable and flexible oxygen sensor for transcutaneous blood gas monitoring was fabricated and tested. The sensor has a laminar film-like structure, which was fabricated by pouching KCl electrolyte solution by both non-permeable (metal weldable) sheet and gas-permeable membrane with Pt- and Ag/AgCl-electrodes patterned using microfabrication process. The electrolyte solution was fixed only by heat-sealing the edges of the weldable membranes without any chemical adhesives. The wearable oxygen sensor (thickness: 84 mum) was applied to the electrochemical measurement with a constant potential of -600 mV vs. Ag/AgCl, thus obtaining the calibration range to dissolved oxygen (DO) from 0.0 to 7.0 mg/l with a correlation coefficient of 0.998 and the quick response time (53.4 s to 90% of a steady-state current), which operate similarly to a commercially available oxygen electrode. The sensor was also utilized to transcutaneous oxygen monitoring for healthy human subject. The sensing region of the wearable oxygen sensor was attached onto the forearm-skin surface of the subject inhaling various concentrations of oxygen. As a result of physiological application, the output current was varied from -6.2 microA to -7.8 microA within 2 min when the concentration of inhaling oxygen was changed from atmospheric air to 60% oxygen. Thus, the transcutaneous oxygen was successfully monitored without any inconveniences such as skin inflammation, etc.

Effect of Fixed Versus Adjusted Transcutaneous Electrical Nerve Stimulation Amplitude on Chronic Mechanical Low Back Pain.

PubMed

Elserty, Noha; Kattabei, Omaima; Elhafez, Hytham

2016-07-01

This study aimed to investigate the effect of adjusting pulse amplitude of transcutaneous electrical nerve stimulation versus fixed pulse amplitude in treatment of chronic mechanical low back pain. Randomized clinical trial. El-sahel Teaching Hospital, Egypt. Forty-five patients with chronic low back pain assigned to three equal groups. Their ages ranged from 20 to 50 years. The three groups received the same exercise program. Group A received transcutaneous electrical nerve stimulation with fixed pulse amplitude for 40 minutes. Group B received transcutaneous electrical nerve stimulation with adjusted pulse amplitude for 40 minutes, with the pulse amplitude adjusted every 5 minutes. Group C received exercises only. Treatment sessions were applied three times per week for 4 weeks for the three groups. A visual analogue scale was used to assess pain severity, the Oswestry Disability Index was used to assess functional level, and a dual inclinometer was used to measure lumbar range of motion. Evaluations were performed before and after treatment. Visual analogue scale, Oswestry Disability Index, and back range of motion significantly differed between the two groups that received transcutaneous electrical nerve stimulation and the control group and did not significantly differ between fixed and adjusted pulse amplitude of transcutaneous electrical nerve stimulation. Adjusting pulse amplitude of transcutaneous electrical nerve stimulation does not produce a difference in the effect of transcutaneous electrical nerve stimulation used to treat chronic low back pain.

Effect of Transcutaneous Electrode Temperature on Accuracy and Precision of Carbon Dioxide and Oxygen Measurements in the Preterm Infants.

PubMed

Jakubowicz, Jessica F; Bai, Shasha; Matlock, David N; Jones, Michelle L; Hu, Zhuopei; Proffitt, Betty; Courtney, Sherry E

2018-05-01

High electrode temperature during transcutaneous monitoring is associated with skin burns in extremely premature infants. We evaluated the accuracy and precision of CO 2 and O 2 measurements using lower transcutaneous electrode temperatures below 42°C. We enrolled 20 neonates. Two transcutaneous monitors were placed simultaneously on each neonate, with one electrode maintained at 42°C and the other randomized to temperatures of 38, 39, 40, 41, and 42°C. Arterial blood was collected twice at each temperature. At the time of arterial blood sampling, values for transcutaneously measured partial pressure of CO 2 (P tcCO 2 ) were not significantly different among test temperatures. There was no evidence of skin burning at any temperature. For P tcCO 2 , Bland-Altman analyses of all test temperatures versus 42°C showed good precision and low bias. Transcutaneously measured partial pressure of O 2 (P tcO 2 ) values trended arterial values but had large negative bias. Transcutaneous electrode temperatures as low as 38°C allow an assessment of P tcCO 2 as accurate as that with electrodes at 42°C. Copyright © 2018 by Daedalus Enterprises.

Weaning mechanical ventilation after off-pump coronary artery bypass graft procedures directed by noninvasive gas measurements.

PubMed

Chakravarthy, Murali; Narayan, Sandeep; Govindarajan, Raghav; Jawali, Vivek; Rajeev, Subramanyam

2010-06-01

Partial pressure of carbon dioxide and oxygen were transcutaneously measured in adults after off-pump coronary artery bypass (OPCAB) surgery. The clinical use of such measurements and interchangeability with arterial blood gas measurements for weaning patients from postoperative mechanical ventilation were assessed. This was a prospective observational study. Tertiary referral heart hospital. Postoperative OPCAB surgical patients. Transcutaneous oxygen and carbon dioxide measurements. In this prospective observational study, 32 consecutive adult patients in a tertiary care medical center underwent OPCAB surgery. Noninvasive measurement of respiratory gases was performed during the postoperative period and compared with arterial blood gases. The investigator was blinded to the reports of arterial blood gas studies and weaned patients using a "weaning protocol" based on transcutaneous gas measurement. The number of patients successfully weaned based on transcutaneous measurements and the number of times the weaning process was held up were noted. A total of 212 samples (pairs of arterial and transcutaneous values of oxygen and carbon dioxide) were obtained from 32 patients. Bland-Altman plots and mountain plots were used to analyze the interchangeability of the data. Twenty-five (79%) of the patients were weaned from the ventilator based on transcutaneous gas measurements alone. Transcutaneous carbon dioxide measurements were found to be interchangeable with arterial carbon dioxide during 96% of measurements, versus 79% for oxygen measurements. More than three fourths of the patients were weaned from mechanical ventilation and extubated based on transcutaneous gas values alone after OPCAB surgery. The noninvasive transcutaneous carbon dioxide measurement can be used as a surrogate for arterial carbon dioxide measurement to manage postoperative OPCAB patients. Copyright 2010 Elsevier Inc. All rights reserved.

Switchable Polymer Based Thin Film Coils as a Power Module for Wireless Neural Interfaces.

PubMed

Kim, S; Zoschke, K; Klein, M; Black, D; Buschick, K; Toepper, M; Tathireddy, P; Harrison, R; Solzbacher, F

2007-05-01

Reliable chronic operation of implantable medical devices such as the Utah Electrode Array (UEA) for neural interface requires elimination of transcutaneous wire connections for signal processing, powering and communication of the device. A wireless power source that allows integration with the UEA is therefore necessary. While (rechargeable) micro batteries as well as biological micro fuel cells are yet far from meeting the power density and lifetime requirements of an implantable neural interface device, inductive coupling between two coils is a promising approach to power such a device with highly restricted dimensions. The power receiving coils presented in this paper were designed to maximize the inductance and quality factor of the coils and microfabricated using polymer based thin film technologies. A flexible configuration of stacked thin film coils allows parallel and serial switching, thereby allowing to tune the coil's resonance frequency. The electrical properties of the fabricated coils were characterized and their power transmission performance was investigated in laboratory condition.

A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty.

PubMed

Beckwée, David; Bautmans, Ivan; Swinnen, Eva; Vermet, Yorick; Lefeber, Nina; Lievens, Pierre; Vaes, Peter

2014-01-01

To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality.

Transcutaneous Vagus Nerve Stimulation: A Promising Method for Treatment of Autism Spectrum Disorders

PubMed Central

Jin, Yu; Kong, Jian

2017-01-01

Transcutaneous Vagus Nerve Stimulation (tVNS) on the auricular branch of the vagus nerve has been receiving attention due to its therapeutic potential for neuropsychiatric disorders. Although the mechanism of tVNS is not yet completely understood, studies have demonstrated the potential role of vagal afferent nerve stimulation in the regulation of mood and visceral state associated with social communication. In addition, a growing body of evidence shows that tVNS can activate the brain regions associated with Autism Spectrum Disorder (ASD), trigger neuroimmune modulation and produce treatment effects for comorbid disorders of ASD such as epilepsy and depression. We thus hypothesize that tVNS may be a promising treatment for ASD, not only for comorbid epilepsy and depression, but also for the core symptoms of ASD. The goal of this manuscript is to summarize the findings and rationales for applying tVNS to treat ASD and propose potential parameters for tVNS treatment of ASD. PMID:28163670

One lesson from arthroplasty to osseointegration in search for better fixation of in-bone implanted prosthesis

PubMed Central

Pitkin, Mark

2011-01-01

Direct transcutaneous prosthetic attachment (osseointegration) consists of implanting directly into the residuum bone a metal pylon whose external fraction connects the residuum to the external prosthesis. Since the introduction of osseointegration about 20 years ago, the obvious challenge associated with this technology has been the skin-pylon interface as a source of infections. In comparison, the bone-device interface was considered less problematic because of the knowledge and experience inherited from dental implantology and total joint replacement (arthroplasty). Current methods of pylon fixation in osseointegration follow arthroplasty’s paradigm of positioning the pylon’s shaft inside the bone’s medullary canal. However, adopting the medullary canal as a holding compartment for the pylon’s shaft creates the problem of shaft loosening, which has not yet been solved in arthroplasty. PMID:18712634

Transcutaneous immunization with cross-reacting material CRM(197) of diphtheria toxin boosts functional antibody levels in mice primed parenterally with adsorbed diphtheria toxoid vaccine.

PubMed

Stickings, Paul; Peyre, Marisa; Coombes, Laura; Muller, Sylviane; Rappuoli, Rino; Del Giudice, Giuseppe; Partidos, Charalambos D; Sesardic, Dorothea

2008-04-01

Transcutaneous immunization (TCI) capitalizes on the accessibility and immunocompetence of the skin, elicits protective immunity, simplifies vaccine delivery, and may be particularly advantageous when frequent boosting is required. In this study we examined the potential of TCI to boost preexisting immune responses to diphtheria in mice. The cross-reacting material (CRM(197)) of diphtheria toxin was used as the boosting antigen and was administered alone or together with either one of two commonly used mucosal adjuvants, cholera toxin (CT) and a partially detoxified mutant of heat-labile enterotoxin of Escherichia coli (LTR72). We report that TCI with CRM(197) significantly boosted preexisting immune responses elicited after parenteral priming with aluminum hydroxide-adsorbed diphtheria toxoid (DTxd) vaccine. In the presence of LTR72 as an adjuvant, toxin-neutralizing antibody titers were significantly higher than those elicited by CRM(197) alone and were comparable to the functional antibody levels induced after parenteral booster immunization with the adsorbed DTxd vaccine. Time course study showed that high levels of toxin-neutralizing antibodies persisted for at least 14 weeks after the transcutaneous boost. In addition, TCI resulted in a vigorous antigen-specific proliferative response in all groups of mice boosted with the CRM(197) protein. These findings highlight the promising prospect of using booster administrations of CRM(197) via the transcutaneous route to establish good herd immunity against diphtheria.

Effectiveness of transcutaneous electrical nerve stimulation and interferential current in primary dysmenorrhea.

PubMed

Tugay, Nazan; Akbayrak, Türkan; Demirtürk, Funda; Karakaya, Ilkim Citak; Kocaacar, Ozge; Tugay, Umut; Karakaya, Mehmet Gürhan; Demirtürk, Fazli

2007-01-01

To compare the effectiveness of transcutaneous electrical nerve stimulation and interferential current in primary dysmenorrhea. A prospective, randomized, and controlled study. Hacettepe University School of Physical Therapy and Rehabilitation. Thirty-four volunteer subjects with primary dysmenorrhea (mean age: 21.35 +/- 1.70 years) were included. Statistical analyses were performed in 32 subjects who completed all measures. Fifteen subjects received interferential current application for 20 minutes and 17 subjects received transcutaneous electrical nerve stimulation for 20 minutes when they were experiencing dysmenorrhea. Physical characteristics, years since menarche, length of menstrual cycle (days), and duration of menstruation (days) were recorded. Visual analog scale ( VAS) intensities of menstrual pain, referred lower limb pain, and low back pain were recorded before treatment, and immediately, 8 hours, and 24 hours after treatment. Intensities of the evaluated parameters decreased beginning from just after the applications in both groups (P<0.05). Intensity of referring low back pain in first three measurement times was different between the groups (P<0.05), but this difference is thought to be due to the baseline values of the groups. So, it can be said that no superiority existed between the methods (P>0.05). Both transcutaneous electrical nerve stimulation and interferential current appear to be effective in primary dysmenorrhea. As they are free from the potentially adverse effects of analgesics, and no adverse effects are reported in the literature nor observed in this study, a clinical trial of their effectiveness in comparison with untreated and placebo-treated control groups is warranted.

Transcutaneous Electrical Nerve Stimulation Combined with Oxybutynin is Superior to Monotherapy in Children with Urge Incontinence: A Randomized, Placebo Controlled Study.

PubMed

Borch, Luise; Hagstroem, Soeren; Kamperis, Konstantinos; Siggaard, C V; Rittig, Soeren

2017-08-01

We evaluated whether combination therapy with transcutaneous electrical nerve stimulation and oxybutynin results in a superior treatment response compared to either therapy alone in children with urge incontinence. In this placebo controlled study 66 children with a mean ± SD age of 7.3 ± 1.6 years who were diagnosed with urge incontinence were randomized to 3 treatment groups. Group 1 consisted of 22 children undergoing transcutaneous electrical nerve stimulation plus active oxybutynin administration. Group 2 included 21 children undergoing active transcutaneous electrical nerve stimulation plus placebo oxybutynin administration. Group 3 consisted of 23 children undergoing active oxybutynin administration plus placebo transcutaneous electrical nerve stimulation. The children received active or placebo transcutaneous electrical nerve stimulation over the sacral S2 to S3 outflow for 2 hours daily in combination with 5 mg active or placebo oxybutynin twice daily. The intervention period was 10 weeks. Primary outcome was number of wet days weekly. Secondary outcomes were severity of incontinence, frequency, maximum voided volume over expected bladder capacity for age, average voided volume over expected bladder capacity for age and visual analogue scale score. Combination therapy was superior to oxybutynin monotherapy, with an 83% greater chance of treatment response (p = 0.05). Combination therapy was also significantly more effective than transcutaneous electrical nerve stimulation monotherapy regarding reduced number of wet days weekly (mean difference -2.28, CI -4.06 to -0.49), severity of incontinence (-3.11, CI -5.98 to -0.23) and daily voiding frequency (-2.82, CI -4.48 to -1.17). Transcutaneous electrical nerve stimulation in combination with oxybutynin for childhood urge incontinence was superior to monotherapy consisting of transcutaneous electrical nerve stimulation or oxybutynin, although the latter only reached borderline statistical significance. Furthermore, transcutaneous electrical nerve stimulation was associated with a decreased risk of oxybutynin induced post-void residual urine greater than 20 ml. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

High-fidelity simulation of transcutaneous cardiac pacing: characteristics and limitations of available high-fidelity simulators, and description of an alternative two-mannequin model.

PubMed

Robitaille, Arnaud; Perron, Roger; Germain, Jean-François; Tanoubi, Issam; Georgescu, Mihai

2015-04-01

Transcutaneous cardiac pacing (TCP) is a potentially lifesaving technique that is part of the recommended treatment for symptomatic bradycardia. Transcutaneous cardiac pacing however is used uncommonly, and its successful application is not straightforward. Simulation could, therefore, play an important role in the teaching and assessment of TCP competence. However, even the highest-fidelity mannequins available on the market have important shortcomings, which limit the potential of simulation. Six criteria defining clinical competency in TCP were established and used as a starting point in the creation of an improved TCP simulator. The goal was a model that could be used to assess experienced clinicians, an objective that justifies the additional effort required by the increased fidelity. The proposed 2-mannequin model (TMM) combines a highly modified Human Patient Simulator with a SimMan 3G, the latter being used solely to provide the electrocardiography (ECG) tracing. The TMM improves the potential of simulation to assess experienced clinicians (1) by reproducing key features of TCP, like using the same multifunctional pacing electrodes used clinically, allowing dual ECG monitoring, and responding with upper body twitching when stimulated, but equally importantly (2) by reproducing key pitfalls of the technique, like allowing pacing electrode misplacement and reproducing false signs of ventricular capture, commonly, but erroneously, used clinically to establish that effective pacing has been achieved (like body twitching, electrical artifact on the ECG, and electrical capture without ventricular capture). The proposed TMM uses a novel combination of 2 high-fidelity mannequins to improve TCP simulation until upgraded mannequins become commercially available.

A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty

PubMed Central

Beckwée, David; Bautmans, Ivan; Swinnen, Eva; Vermet, Yorick; Lefeber, Nina; Lievens, Pierre

2014-01-01

Objective: To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. Data Sources: PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Review Methods: Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. Results: A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. Conclusion: This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality. PMID:26770730

Use of a combined oxygen and carbon dioxide transcutaneous electrode in the estimation of gas exchange during exercise.

PubMed Central

Sridhar, M K; Carter, R; Moran, F; Banham, S W

1993-01-01

BACKGROUND--Accurate and reliable measurement of gas exchange during exercise has traditionally involved arterial cannulation. Non-invasive devices to estimate arterial oxygen (O2) and carbon dioxide (CO2) tensions are now available. A method has been devised and evaluated for measuring gas exchange during exercise with a combined transcutaneous O2 and CO2 electrode. METHODS--Symptom limited exercise tests were carried out in 24 patients reporting effort intolerance and breathlessness. Exercise testing was performed by bicycle ergometry with a specifically designed protocol involving gradual two minute workload increments. Arterial O2 and CO2 tensions were measured at rest and during exercise by direct blood sampling from an indwelling arterial cannula and a combined transcutaneous electrode heated to 45 degrees C. The transcutaneous system was calibrated against values obtained by direct arterial sampling before each test. RESULTS--In all tests the trend of gas exchange measured by the transcutaneous system was true to the trend measured from direct arterial sampling. In the 140 measurements the mean difference between the O2 tensions estimated by direct sampling and the transcutaneous method was 0.08 kPa (0.62 mm Hg, limits of agreement 4.42 and -3.38 mm Hg). The mean difference between the methods for CO2 was 0.02 kPa (0.22 mm Hg, limits of agreement 2.20 and -1.70 mm Hg). There was no morbidity associated with the use of the transcutaneous electrode heated to 45 degrees C. CONCLUSIONS--A combined transcutaneous O2 and CO2 electrode heated to 45 degrees C can be used to provide a reliable estimate of gas exchange during gradual incremental exercise in adults. PMID:8346496

The effect of intra-operative transcutaneous electrical nerve stimulation on posterior neck pain following thyroidectomy.

PubMed

Park, C; Choi, J B; Lee, Y-S; Chang, H-S; Shin, C S; Kim, S; Han, D W

2015-04-01

Posterior neck pain following thyroidectomy is common because full neck extension is required during the procedure. We evaluated the effect of intra-operative transcutaneous electrical nerve stimulation on postoperative neck pain in patients undergoing total thyroidectomy under general anaesthesia. One hundred patients were randomly assigned to one of two groups; 50 patients received transcutaneous electrical nerve stimulation applied to the trapezius muscle and 50 patients acted as controls. Postoperative posterior neck pain and anterior wound pain were evaluated using an 11-point numerical rating scale at 30 min, 6 h, 24 h and 48 h following surgery. The numerical rating scale for posterior neck pain was significantly lower in the transcutaneous electrical nerve stimulation group compared with the control group at all time points (p < 0.05). There were no significant differences in the numerical rating scale for anterior wound pain at any time point. No adverse effects related to transcutaneous electrical nerve stimulation were observed. We conclude that intra-operative transcutaneous electrical nerve stimulation applied to the trapezius muscle reduced posterior neck pain following thyroidectomy. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

The effect of transcutaneous electrical nerve stimulation in patients with acute exacerbation of chronic obstructive pulmonary disease: randomised controlled trial.

PubMed

Öncü, Emine; Zincir, Handan

2017-07-01

The aim of the present study was to assess the efficacy of transcutaneous electrical nerve stimulation in patients with acute exacerbation of chronic obstructive pulmonary disease. In patients with stable chronic obstructive pulmonary disease, transcutaneous electrical nerve stimulation has been known to attain improvement in forced expiratory volume in 1 seconds, physical activity, and quality of life. However, information about the effects of transcutaneous electrical nerve stimulation on acute exacerbation of chronic obstructive pulmonary disease is quite limited. A single-blind, randomised controlled trial. Data were collected between August 2013-May 2014. Eighty-two patients who were hospitalised with a diagnosis of acute exacerbation of chronic obstructive pulmonary disease were randomly assigned to a transcutaneous electrical nerve stimulation group receiving transcutaneous electrical nerve stimulation treatment for 20 seance over the acupuncture points with pharmacotherapy or placebo group receiving the same treatment without electrical current output from the transcutaneous electrical nerve stimulation device. Pulmonary functional test, six-minute walking distance, dyspnoea and fatigue scale, and St. George's Respiratory Questionnaire scores were assessed pre- and postprogram. The program started at the hospital by the researcher was sustained in the patient's home by the caregiver. All patients were able to complete the program, despite the exacerbation. The 20 seance transcutaneous electrical nerve stimulation program provided clinically significant improvement in forced expiratory volume in 1 seconds 21 ml, 19·51% but when compared with the placebo group, the difference was insignificant (p > 0·05). The six-minute walking distance increased by 48·10 m more in the placebo group (p < 0·05). There were no significant differences between the two groups' St. George's Respiratory Questionnaire, dyspnoea and fatigue score (p > 0·05). Adding transcutaneous electrical nerve stimulation therapy to pharmacotherapy in patients with acute exacerbation of chronic obstructive pulmonary disease provided clinical improvement in forced expiratory volume in 1 seconds and add benefit in exercise capacity, but no significant effect on the other outcomes measured. Transcutaneous electrical nerve stimulation can be used as a non-invasive complementary therapy due to its beneficial effects on forced expiratory volume in 1 seconds and exercise capacity in patients with acute exacerbation of chronic obstructive pulmonary disease. © 2016 John Wiley & Sons Ltd.

Transcutaneous Electrical Nerve Stimulation in Children with Monosymptomatic Nocturnal Enuresis: A Randomized, Double-Blind, Placebo Controlled Study.

PubMed

Jørgensen, Cecilie Siggaard; Kamperis, Konstantinos; Borch, Luise; Borg, Britt; Rittig, Søren

2017-09-01

In a third of all children with monosymptomatic nocturnal enuresis their condition is refractory to first line treatments. Transcutaneous electrical nerve stimulation has been documented to be efficacious in children with daytime incontinence. We investigated the effect of transcutaneous electrical nerve stimulation in children with monosymptomatic nocturnal enuresis without nocturnal polyuria. Children with monosymptomatic nocturnal enuresis (3 or more wet nights per week) and no nocturnal polyuria were randomized to treatment with active or sham transcutaneous electrical nerve stimulation involving 1-hour sessions twice daily for 10 weeks in a double-blind design. Of the 52 children with monosymptomatic nocturnal enuresis included in the study 47 completed treatment (mean age 9.5 ± 2.1 years, 38 males). None of the children experienced a full response with complete remission of enuresis. Treatment with transcutaneous electrical nerve stimulation did not lead to significant changes in number of wet nights, nocturnal urine production on wet or dry nights, maximum voided volume with and without first morning voided volume, or voiding frequency when comparing parameters before and after treatment. The present study demonstrates no anti-enuretic effect of transcutaneous electrical nerve stimulation in children with monosymptomatic nocturnal enuresis without nocturnal polyuria. Nocturnal urine production and bladder capacity remained unchanged during and after treatment with transcutaneous electrical nerve stimulation. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Trans-Cutaneous Bilirubinometery versus Serum Bilirubin in Neonatal Jaundice.

PubMed

Mahram, Manoochehr; Oveisi, Sonia; Jaberi, Najmeh

2015-12-01

Hyperbilirubinemia is a common problem in neonates and causes serious complications. Thus, serial measurements of bilirubin should be done. This assessment is done through two methods of laboratory measurement in serum sample and transcutaneous bilirubinometer. This descriptive study compared transcutaneous bilirubin assessment and laboratory serum bilirubin. Bilirubin level was assessed among 256 neonates admitted to the Qods Children's Hospital in Qazvin- Iran, because of neonatal indirect jaundice, through two methods of transcutaneous bilirubinometery from two sites of forehead and sternum and laboratory measurement of bilirubin in serum. The cases were non-hemolytic icteric term neonates weighing 2500 gram or more and had not received phototherapy or other treatments. Neonates with hemolytic forms of jaundice, sepsis and suspicious to metabolic disorders were excluded. Assessments by means of KJ-8000 transcutaneous bilirubinometer from two sites of forehead and sternum and through laboratory measurement of serum bilirubin were registered and analyzed. The results of the current study showed that there was a correlation of 0.82 between serum bilirubin and transcutaneous forehead bilirubin assessment and for the used device sensitivity of 0.844; specificity of 0.842, Youden Index of 0.709 and Shortest of 0.042 for a cut-off of 12.4 in bilirubin of participants. Furthermore, Likelihood Ratio positive and negative (LR) were 5.665 and 0.164, respectively and diagnostic Odds Ratio (LR+/LR-) was 34.56. Transcutaneous bilirubinometery can be considered as a reliable tool to assess bilirubin for the screening of neonatal jaundice in term neonates.

Diagnostic Usefulness of Transcutaneous Bilirubinometry in Very Preterm Newborns

PubMed Central

Badiee, Zohreh; Mohammadizadeh, Majid; Shamee, Masih

2012-01-01

Background: This study was performed to find out whether transcutaneous bilirubinometry could be a valid screening method for hyperbilirubinemia in preterm infants, especially for those who needed mechanical ventilation. Methods: We evaluated 63 preterm Iranian newborns who were managed in the neonatal intensive care unit of Shahidbeheshti University Hospital, Isfahan, Iran from April 2009 to April 2010. Transcutaneous bilirubin (TCB) measurements were obtained using BiliCheck™ shortly before or 10 minutes after taking blood for determination of the plasma bilirubin level in premature newborns, who did not receive phototherapy. We assessed the correlation between the transcutaneous bilirubin and plasma bilirubin level by linear regression analysis. We also analyzed the gestational age, birth weight, postnatal age, sex, and hematocrit, for determination of their effect on transcutaneous bilirubin accuracy. Results: The overall bilirubin concentration ranged from 5.4 to 17 mg/dL and from 4.8 to 17.3 mg/dl for total serum bilirubin (TSB) and transcutaneous bilirubin, respectively. The mean values obtained by transcutaneous bilirubinometry were slightly higher than the total TSB values. The correlation coefficient between TSB and TCB was r=0.82, P<0.001, and this was not influenced by gestational age, postnatal age or hematocrit, which were previously considered to be important. The correlation coefficient between TSB and TCB in mechanically ventilated preterm infants was r=0.75, P<0.001. Conclusion: Plasma bilirubin level can be accurately measured by BiliCheck™ in premature newborns, even in newborns who need mechanical ventilation. PMID:22624082

[A non-invasive portable blood-glucose monitoring system: sampling of suction effusion fluid].

PubMed

Arai, T; Kayashima, S; Kikuchi, M; Kaneyoshi, A; Itoh, N

1995-04-01

We developed a new portable transcutaneous blood glucose monitoring system using non-invasive collection of suction effusion fluid (SEF) from human skin. A ion sensitive field effect transistor (ISFET) sensor was employed to measure glucose concentration in a very small quantity of the SEF. The system was composed of a couple of portions. One structure was a suction cell, and the other was a main frame. The suction cell included the ISFET glucose sensor, a dilution mechanism, and a sucking interface to human skin. The main frame contained a dilution solution reservoir, a liquid waste reservoir, a fluid pump, a vacuum pump, a micro processor, batteries, and a user interface. The system is self-contained for portable usage during up to 6 hrs monitoring. This system may be the first blood glucose monitoring equipment which does not use blood sampling.

Active Microelectronic Neurosensor Arrays for Implantable Brain Communication Interfaces

PubMed Central

Song, Y.-K.; Borton, D. A.; Park, S.; Patterson, W. R.; Bull, C. W.; Laiwalla, F.; Mislow, J.; Simeral, J. D.; Donoghue, J. P.; Nurmikko, A. V.

2010-01-01

We have built a wireless implantable microelectronic device for transmitting cortical signals transcutaneously. The device is aimed at interfacing a microelectrode array cortical to an external computer for neural control applications. Our implantable microsystem enables presently 16-channel broadband neural recording in a non-human primate brain by converting these signals to a digital stream of infrared light pulses for transmission through the skin. The implantable unit employs a flexible polymer substrate onto which we have integrated ultra-low power amplification with analog multiplexing, an analog-to-digital converter, a low power digital controller chip, and infrared telemetry. The scalable 16-channel microsystem can employ any of several modalities of power supply, including via radio frequency by induction, or infrared light via a photovoltaic converter. As of today, the implant has been tested as a sub-chronic unit in non-human primates (~ 1 month), yielding robust spike and broadband neural data on all available channels. PMID:19502132

Volume conductor model of transcutaneous electrical stimulation with kilohertz signals

PubMed Central

Medina, Leonel E.; Grill, Warren M.

2014-01-01

Objective Incorporating high-frequency components in transcutaneous electrical stimulation (TES) waveforms may make it possible to stimulate deeper nerve fibers since the impedance of tissue declines with increasing frequency. However, the mechanisms of high-frequency TES remain largely unexplored. We investigated the properties of TES with frequencies beyond those typically used in neural stimulation. Approach We implemented a multilayer volume conductor model including dispersion and capacitive effects, coupled to a cable model of a nerve fiber. We simulated voltage- and current-controlled transcutaneous stimulation, and quantified the effects of frequency on the distribution of potentials and fiber excitation. We also quantified the effects of a novel transdermal amplitude modulated signal (TAMS) consisting of a non-zero offset sinusoidal carrier modulated by a square-pulse train. Main results The model revealed that high-frequency signals generated larger potentials at depth than did low frequencies, but this did not translate into lower stimulation thresholds. Both TAMS and conventional rectangular pulses activated more superficial fibers in addition to the deeper, target fibers, and at no frequency did we observe an inversion of the strength-distance relationship. Current regulated stimulation was more strongly influenced by fiber depth, whereas voltage regulated stimulation was more strongly influenced by skin thickness. Finally, our model reproduced the threshold-frequency relationship of experimentally measured motor thresholds. Significance The model may be used for prediction of motor thresholds in TES, and contributes to the understanding of high-frequency TES. PMID:25380254

Volume conductor model of transcutaneous electrical stimulation with kilohertz signals

NASA Astrophysics Data System (ADS)

Medina, Leonel E.; Grill, Warren M.

2014-12-01

Objective. Incorporating high-frequency components in transcutaneous electrical stimulation (TES) waveforms may make it possible to stimulate deeper nerve fibers since the impedance of tissue declines with increasing frequency. However, the mechanisms of high-frequency TES remain largely unexplored. We investigated the properties of TES with frequencies beyond those typically used in neural stimulation. Approach. We implemented a multilayer volume conductor model including dispersion and capacitive effects, coupled to a cable model of a nerve fiber. We simulated voltage- and current-controlled transcutaneous stimulation, and quantified the effects of frequency on the distribution of potentials and fiber excitation. We also quantified the effects of a novel transdermal amplitude modulated signal (TAMS) consisting of a non-zero offset sinusoidal carrier modulated by a square-pulse train. Main results. The model revealed that high-frequency signals generated larger potentials at depth than did low frequencies, but this did not translate into lower stimulation thresholds. Both TAMS and conventional rectangular pulses activated more superficial fibers in addition to the deeper, target fibers, and at no frequency did we observe an inversion of the strength-distance relationship. Current regulated stimulation was more strongly influenced by fiber depth, whereas voltage regulated stimulation was more strongly influenced by skin thickness. Finally, our model reproduced the threshold-frequency relationship of experimentally measured motor thresholds. Significance. The model may be used for prediction of motor thresholds in TES, and contributes to the understanding of high-frequency TES.

Laser microporation of the skin: prospects for painless application of protective and therapeutic vaccines

PubMed Central

Scheiblhofer, Sandra; Thalhamer, Josef; Weiss, Richard

2013-01-01

Introduction: In contrast to muscle and subcutaneous tissue, the skin is easily accessible and provides unique immunological properties. Increasing knowledge about the complex interplay of skin-associated cell types in the development of cutaneous immune responses has fueled efforts to target the skin for vaccination as well as for immunotherapy. Areas covered: This review provides an overview on skin layers and their resident immunocompetent cell types. Advantages and shortcomings of standard methods and innovative technologies to circumvent the outermost skin barrier are addressed. Studies employing fractional skin ablation by infrared lasers for cutaneous delivery of drugs, as well as high molecular weight molecules such as protein antigens or antibodies, are reviewed, and laserporation is introduced as a versatile transcutaneous vaccination platform. Specific targeting of the epidermis or the dermis by different laser settings, the resulting kinetics of uptake and transport and the immune response types elicited are discussed, and the potential of this transcutaneous delivery platform for allergen-specific immunotherapy is demonstrated. Expert opinion: Needle-free and painless vaccination approaches have the potential to replace standard methods due to their improved safety and optimal patient compliance. The use of fractional laser devices for stepwise ablation of skin layers might be advantageous for both vaccination against microbial pathogens, as well as immunotherapeutic approaches, such as allergen-specific immunotherapy. Thorough investigation of the underlying immunological mechanisms will help to provide the knowledge for a rational design of transcutaneous protective/therapeutic vaccines. PMID:23425032

Reduced local field potential power in the medial prefrontal cortex by noxious stimuli.

PubMed

Li, Ai-Ling; Yang, Xiaofei; Chiao, Jung-Chih; Peng, Yuan Bo

2016-10-01

Nociceptive signals produced by noxious stimuli at the periphery reach the brain through ascending pathways. These signals are processed by various brain areas and lead to activity changes in those areas. The medial prefrontal cortex (mPFC) is involved in higher cognitive functions and emotional processing. It receives projections from brain areas involved in nociception. In this study, we investigated how nociceptive input from the periphery changes the local field potential (LFP) activity in the mPFC. Three different types of noxious stimuli were applied to the hind paw contralateral to the LFP recording site. They were transcutaneous electrical stimulations, mechanical stimuli and a chemical stimulus (formalin injection). High intensity transcutaneous stimulations (10V to 50V) and noxious mechanical stimulus (pinch) significantly reduced the LFP power during the stimulating period (p<0.05), but not the low intensity subcutaneous stimulations (0.1V to 5V) and other innocuous mechanical stimuli (brush and pressure). More frequency bands were inhibited with increased intensity of transcutaneous electrical stimulation, and almost all frequency bands were inhibited by stimulations at or higher than 30v. Pinch significantly reduced the power for beta band and formalin injection significantly reduced the power of alpha and beta band. Our data demonstrated the noxious stimuli-induced reduction of LFP power in the mPFC, which indicates the active processing of nociceptive information by the mPFC. Copyright © 2016 Elsevier Inc. All rights reserved.

Influence of transcutaneous electrical nerve stimulation on spasticity, balance, and walking speed in stroke patients: A systematic review and meta-analysis.

PubMed

Lin, Shuqin; Sun, Qi; Wang, Haifeng; Xie, Guomin

2018-01-10

To evaluate the influence of transcutaneous electrical nerve stimulation in patients with stroke through a systematic review and meta-analysis. PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases were searched systematically. Randomized controlled trials assessing the effect of transcutaneous electrical nerve stimulation vs placebo transcutaneous electrical nerve stimulation on stroke were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome was modified Ashworth scale (MAS). Meta-analysis was performed using the random-effect model. Seven randomized controlled trials were included in the meta-analysis. Compared with placebo transcutaneous electrical nerve stimulation, transcutaneous electrical nerve stimulation supplementation significantly reduced MAS (standard mean difference (SMD) = -0.71; 95% confidence interval (95% CI) = -1.11 to -0.30; p = 0.0006), improved static balance with open eyes (SMD = -1.26; 95% CI = -1.83 to -0.69; p<0.0001) and closed eyes (SMD = -1.74; 95% CI = -2.36 to -1.12; p < 0.00001), and increased walking speed (SMD = 0.44; 95% CI = 0.05 to 0.84; p = 0.03), but did not improve results on the Timed Up and Go Test (SMD = -0.60; 95% CI=-1.22 to 0.03; p = 0.06). Transcutaneous electrical nerve stimulation is associated with significantly reduced spasticity, increased static balance and walking speed, but has no influence on dynamic balance.

Preliminary results of sacral transcutaneous electrical nerve stimulation for fecal incontinence.

PubMed

Leung, Edmund; Francombe, James

2013-03-01

Fecal incontinence is a common debilitating condition. The aim of this study is to investigate the feasibility of sacral transcutaneous electrical nerve stimulation as an alternative treatment modality for fecal incontinence. All consecutive patients who presented with fecal incontinence to the senior author's clinic were prospectively recruited between June 2009 and September 2010. The severity of their fecal incontinence was assessed by the Wexner and Vaizey scores and anal physiology. Any improvement following a period of sacral transcutaneous electrical nerve stimulation treatment was determined by repeating the scores. In addition, patient satisfaction with the procedure was assessed by using a patient impression score. Twenty female patients with a median age of 57.5 years (range, 30-86) were evaluated. The median follow-up was 10 months (range, 5-12 months). Two patients did not record a change in their Vaizey score. The overall mean Wexner score was 7.9 ± 4.2 before in comparison with 4.0 ± 3.1 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 2.2-5.7, SE = 0.832). The overall mean Vaizey score was 12.7 ± 5.7 before in comparison with 5.8 ± 5.6 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 4.5-9.4, SE = 1.162). The pretreatment patient impression score was set at a mean of 1 ± 0 in comparison with 2.8 ± 1.1 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 1.2-2.3, SE = 0.25). The preliminary results suggest sacral transcutaneous electrical nerve stimulation is a promising noninvasive alternative to existing modalities in the treatment of idiopathic fecal incontinence.

Posterior tibial nerve stimulation vs parasacral transcutaneous neuromodulation for overactive bladder in children.

PubMed

Barroso, Ubirajara; Viterbo, Walter; Bittencourt, Joana; Farias, Tiago; Lordêlo, Patrícia

2013-08-01

Parasacral transcutaneous electrical nerve stimulation and posterior tibial nerve stimulation have emerged as effective methods to treat overactive bladder in children. However, to our knowledge no study has compared the 2 methods. We evaluated the results of parasacral transcutaneous electrical nerve stimulation and posterior tibial nerve stimulation in children with overactive bladder. We prospectively studied children with overactive bladder without dysfunctional voiding. Success of treatment was evaluated by visual analogue scale and dysfunctional voiding symptom score, and by level of improvement of each specific symptom. Parasacral transcutaneous electrical nerve stimulation was performed 3 times weekly and posterior tibial nerve stimulation was performed once weekly. A total of 22 consecutive patients were treated with posterior tibial nerve stimulation and 37 with parasacral transcutaneous electrical nerve stimulation. There was no difference between the 2 groups regarding demographic characteristics or types of symptoms. Concerning the evaluation by visual analogue scale, complete resolution of symptoms was seen in 70% of the group undergoing parasacral transcutaneous electrical nerve stimulation and in 9% of the group undergoing posterior tibial nerve stimulation (p = 0.02). When the groups were compared, there was no statistically significant difference (p = 0.55). The frequency of persistence of urgency and diurnal urinary incontinence was nearly double in the group undergoing posterior tibial nerve stimulation. However, this difference was not statistically significant. We found that parasacral transcutaneous electrical nerve stimulation is more effective in resolving overactive bladder symptoms, which matches parental perception. However, there were no statistically significant differences in the evaluation by dysfunctional voiding symptom score, or in complete resolution of urgency or diurnal incontinence. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Randomized clinical trial of transcutaneous electrical posterior tibial nerve stimulation versus lateral internal sphincterotomy for treatment of chronic anal fissure.

PubMed

Youssef, Tamer; Youssef, Mohamed; Thabet, Waleed; Lotfy, Ahmed; Shaat, Reham; Abd-Elrazek, Eman; Farid, Mohamed

2015-10-01

The objective of this study was to evaluate the efficacy of transcutaneous electrical posterior tibial nerve stimulation in treatment of patients with chronic anal fissure and to compare it with the conventional lateral internal sphincterotomy. Consecutive patients with chronic anal fissure were randomly allocated into two treatment groups: transcutaneous electrical posterior tibial nerve stimulation group and lateral internal sphincterotomy group. The primary outcome measures were number of patients with clinical improvement and healed fissure. Secondary outcome measures were complications, VAS pain scores, Wexner's constipation and Peascatori anal incontinence scores, anorectal manometry, and quality of life index. Seventy-three patients were randomized into two groups of 36 patients who were subjected to transcutaneous electrical nerve stimulation and 37 patients who underwent lateral internal sphincterotomy. All (100%) patients in lateral internal sphincterotomy group had clinical improvement at one month following the procedure in contrast to 27 (75%) patients in transcutaneous electrical nerve stimulation group. Recurrence of anal fissure after one year was reported in one (2.7%) and 11 (40.7%) patients in lateral internal sphincterotomy and transcutaneous electrical nerve stimulation groups respectively. Resting anal pressure and functional anal canal length were significantly reduced after lateral internal sphincterotomy. Transcutaneous electrical posterior tibial nerve stimulation for treatment of chronic anal fissure is a novel, non-invasive procedure and has no complications. However, given the higher rate of clinical improvement and fissure healing and the lower rate of fissure recurrence, lateral internal sphincterotomy remains the gold standard for treating chronic anal fissure. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

One-shot percutaneous electrical nerve stimulation vs. transcutaneous electrical nerve stimulation for low back pain: comparison of therapeutic effects.

PubMed

Hsieh, Ru-Lan; Lee, Wen-Chung

2002-11-01

To investigate the therapeutic effects of one shot of low-frequency percutaneous electrical nerve stimulation one shot of transcutaneous electrical nerve stimulation in patients with low back pain. In total, 133 low back pain patients were recruited for this randomized, control study. Group 1 patients received medication only. Group 2 patients received medication plus one shot of percutaneous electrical nerve stimulation. Group 3 patients received medication plus one shot of transcutaneous electrical nerve stimulation. Therapeutic effects were measured using a visual analog scale, body surface score, pain pressure threshold, and the Quebec Back Pain Disability Scale. Immediately after one-shot treatment, the visual analog scale improved 1.53 units and the body surface score improved 3.06 units in the percutaneous electrical nerve stimulation group. In the transcutaneous electrical nerve stimulation group, the visual analog scale improved 1.50 units and the body surface score improved 3.98 units. The improvements did not differ between the two groups. There were no differences in improvement at 3 days or 1 wk after the treatment among the three groups. Simple one-shot treatment with percutaneous electrical nerve stimulation or transcutaneous electrical nerve stimulation provided immediate pain relief for low back pain patients. One-shot transcutaneous electrical nerve stimulation treatment is recommended due to the rarity of side effects and its convenient application.

Tissue Variability and Antennas for Power Transfer to Wireless Implantable Medical Devices.

PubMed

Bocan, Kara N; Mickle, Marlin H; Sejdic, Ervin

2017-01-01

The design of effective transcutaneous systems demands the consideration of inevitable variations in tissue characteristics, which vary across body areas, among individuals, and over time. The purpose of this paper was to design and evaluate several printed antenna topologies for ultrahigh frequency (UHF) transcutaneous power transfer to implantable medical devices, and to investigate the effects of variations in tissue properties on dipole and loop topologies. Here, we show that a loop antenna topology provides the greatest achievable gain with the smallest implanted antenna, while a dipole system provides higher impedance for conjugate matching and the ability to increase gain with a larger external antenna. In comparison to the dipole system, the loop system exhibits greater sensitivity to changes in tissue structure and properties in terms of power gain, but provides higher gain when the separation is on the order of the smaller antenna dimension. The dipole system was shown to provide higher gain than the loop system at greater implant depths for the same implanted antenna area, and was less sensitive to variations in tissue properties and structure in terms of power gain at all investigated implant depths. The results show the potential of easily-fabricated, low-cost printed antenna topologies for UHF transcutaneous power, and the importance of environmental considerations in choosing the antenna topology.

Transcutaneous vaccination via laser microporation

PubMed Central

Weiss, Richard; Hessenberger, Michael; Kitzmüller, Sophie; Bach, Doris; Weinberger, Esther E.; Krautgartner, Wolf D.; Hauser-Kronberger, Cornelia; Malissen, Bernard; Boehler, Christof; Kalia, Yogeshvar N.; Thalhamer, Josef; Scheiblhofer, Sandra

2012-01-01

Driven by constantly increasing knowledge about skin immunology, vaccine delivery via the cutaneous route has recently gained renewed interest. Considering its richness in immunocompetent cells, targeting antigens to the skin is considered to be more effective than intramuscular or subcutaneous injections. However, circumvention of the superficial layer of the skin, the stratum corneum, represents the major challenge for cutaneous immunization. An optimal delivery method has to be effective and reliable, but also highly adaptable to specific demands, should avoid the use of hypodermic needles and the requirement of specially trained healthcare workers. The P.L.E.A.S.E.® (Precise Laser Epidermal System) device employed in this study for creation of aqueous micropores in the skin fulfills these prerequisites by combining the precision of its laser scanning technology with the flexibility to vary the number, density and the depth of the micropores in a user-friendly manner. We investigated the potential of transcutaneous immunization via laser-generated micropores for induction of specific immune responses and compared the outcomes to conventional subcutaneous injection. By targeting different layers of the skin we were able to bias polarization of T cells, which could be modulated by addition of adjuvants. The P.L.E.A.S.E.® device represents a highly effective and versatile platform for transcutaneous vaccination. PMID:22750193

Tissue Variability and Antennas for Power Transfer to Wireless Implantable Medical Devices

PubMed Central

Bocan, Kara N.; Mickle, Marlin H.

2017-01-01

The design of effective transcutaneous systems demands the consideration of inevitable variations in tissue characteristics, which vary across body areas, among individuals, and over time. The purpose of this paper was to design and evaluate several printed antenna topologies for ultrahigh frequency (UHF) transcutaneous power transfer to implantable medical devices, and to investigate the effects of variations in tissue properties on dipole and loop topologies. Here, we show that a loop antenna topology provides the greatest achievable gain with the smallest implanted antenna, while a dipole system provides higher impedance for conjugate matching and the ability to increase gain with a larger external antenna. In comparison to the dipole system, the loop system exhibits greater sensitivity to changes in tissue structure and properties in terms of power gain, but provides higher gain when the separation is on the order of the smaller antenna dimension. The dipole system was shown to provide higher gain than the loop system at greater implant depths for the same implanted antenna area, and was less sensitive to variations in tissue properties and structure in terms of power gain at all investigated implant depths. The results show the potential of easily-fabricated, low-cost printed antenna topologies for UHF transcutaneous power, and the importance of environmental considerations in choosing the antenna topology. PMID:29018637

Clinical diagnosis by transcutaneous Doppler ultrasound

PubMed Central

Wyse, R. K. H.

1982-01-01

Transcutaneous Doppler ultrasound represents a convenient, reliable technique for the non-invasive diagnosis and assessment of a rapidly increasing number of diverse circulatory disorders. ImagesFig. 2Fig. 3 PMID:7050948

Improvement in magnetic field immunity of externally-coupled transcutaneous energy transmission system for a totally implantable artificial heart.

PubMed

Yamamoto, Takahiko; Koshiji, Kohji; Homma, Akihiko; Tatsumi, Eisuke; Taenaka, Yoshiyuki

2008-01-01

Transcutaneous energy transmission (TET) that uses electromagnetic induction between the external and internal coils of a transformer is the most promising method to supply driving energy to a totally implantable artificial heart without invasion. Induction-heating (IH) cookers generate magnetic flux, and if a cooker is operated near a transcutaneous transformer, the magnetic flux generated will link with the external and internal coils of the transcutaneous transformer. This will affect the performance of the TET and the artificial heart system. Hence, it is necessary to improve the magnetic field immunity of the TET system. During operation of the system, if the transcutaneous transformer is in close proximity to an IH cooker, the electric power generated by the cooker and coupled to the transformer can drive the artificial heart system. To prevent this coupling, the external coil was shielded with a conductive shield that had a slit in it. This reduces the coupling between the transformer and the magnetic field generated by the induction cooker. However, the temperature of the shield increased due to heating by eddy currents. The temperature of the shield can be reduced by separating the IH cooker and the shield.

Establishing Multiscale Models for Simulating Whole Limb Estimates of Electric Fields for Osseointegrated Implants

PubMed Central

Isaacson, Brad M.; Stinstra, Jeroen G.; Bloebaum, Roy D.; Pasquina, COL Paul F.; MacLeod, Rob S.

2011-01-01

Although the survival rates of warfighters in recent conflicts are among the highest in military history, those who have sustained proximal limb amputations, may pose additional rehabilitation concerns. In some of these cases, traditional prosthetic limbs may not provide adequate function for returning to an active lifestyle. Osseointegration has emerged as a potential prosthetic alternative for those with limited residual limb length. Using this technology, direct skeletal attachment occurs between a transcutaneous osseointegrated implant (TOI) and the host bone, thereby eliminating the need for a socket. While reports from the first 100 patients with a TOI have been promising, some rehabilitation regimens require 12–18 months of restricted weight bearing to prevent overloading at the bone implant-interface. Electrically induced osseointegration has been proposed as an option for expediting periprosthetic fixation and preliminary studies have demonstrated the feasibility of adapting the TOI into a functional cathode. To assure safe and effective electrical fields that are conducive for osseoinduction and osseointegration, we have developed multiscale modeling approaches to simulate the expected electric metrics at the bone-implant interface. We have used computed tomography scans and volume segmentation tools to create anatomically accurate models that clearly distinguish tissue parameters and serve as the basis for finite element analysis. This translational computational biological process has supported biomedical electrode design, implant placement, and experiments to date have demonstrated the clinical feasibility of electrically induced osseointegration. PMID:21712151

Reduction of skin damage from transcutaneous oxygen electrodes using a spray on dressing.

PubMed Central

Evans, N J; Rutter, N

1986-01-01

A spray on, copolymer acrylic dressing (Op-Site) was used to limit the skin damage caused by a transcutaneous oxygen electrode and its adhesive ring. Two identical electrodes were applied to the abdominal skin of 10 preterm infants, one on untreated skin, the other after application of Op-Site. It was found that Op-Site prevented the epidermal damage (as measured by transepidermal water loss) that occurs when the adhesive ring is removed from untreated skin. It did not interfere with transcutaneous oxygen measurements; absolute values and response times were unchanged. Op-Site is therefore useful in preventing the skin trauma that occurs when transcutaneous oxygen monitoring is being performed in preterm infants below 30 weeks' gestation in the first week of life. Care must be taken, however, to prevent a build up of Op-Site--it should be applied as a single layer, allowed to dry, and removed after use. PMID:3767417

Reduction of skin damage from transcutaneous oxygen electrodes using a spray on dressing.

PubMed

Evans, N J; Rutter, N

1986-09-01

A spray on, copolymer acrylic dressing (Op-Site) was used to limit the skin damage caused by a transcutaneous oxygen electrode and its adhesive ring. Two identical electrodes were applied to the abdominal skin of 10 preterm infants, one on untreated skin, the other after application of Op-Site. It was found that Op-Site prevented the epidermal damage (as measured by transepidermal water loss) that occurs when the adhesive ring is removed from untreated skin. It did not interfere with transcutaneous oxygen measurements; absolute values and response times were unchanged. Op-Site is therefore useful in preventing the skin trauma that occurs when transcutaneous oxygen monitoring is being performed in preterm infants below 30 weeks' gestation in the first week of life. Care must be taken, however, to prevent a build up of Op-Site--it should be applied as a single layer, allowed to dry, and removed after use.

Effect of transcutaneous electrical nerve stimulation for pain control after total knee arthroplasty: A systematic review and meta-analysis.

PubMed

Zhu, Yongjun; Feng, Yuxing; Peng, Lihua

2017-11-21

Transcutaneous electrical nerve stimulation is a possible adjunctive therapy to pharmacological treatment for controlling pain after total knee arthroplasty. However, the results are controversial. A systematic review and meta-analysis was conducted to explore the effect of transcutaneous electrical nerve stimulation on patients with total knee arthroplasty. PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases were searched systematically. Randomized controlled trials assessing the effect of transcutaneous electrical nerve stimulation on patients with total knee arthroplasty were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. Primary outcome was visual analogue scale (VAS) score over a period of 24 h. Meta-analysis was performed using a random-effect model. Six randomized controlled trials involving 529 patients were included in the meta-analysis. Overall, compared with control intervention, transcutaneous electrical nerve stimulation supplementation intervention was found to significantly reduce VAS scores and total postoperative morphine dose over a period of 24 h, and to improve active range of knee motion (standard mean difference (SMD) = 0.37; 95% confidence interval (95% CI) = 0.06-0.68; p = 0.02), but had no effect on VAS scores at 2 weeks (SMD = 0.20; 95% CI = -0.07 to 0.48; p = 0.15). Compared with control intervention, transcutaneous electrical nerve stimulation supplementation intervention was found to significantly reduce pain and morphine requirement over a period of 24 h and to promote functional recovery in patients who have undergone total knee arthroplasty.

Transcutaneous electrical nerve stimulation and interferential current demonstrate similar effects in relieving acute and chronic pain: a systematic review with meta-analysis.

PubMed

Almeida, Camila Cadena de; Silva, Vinicius Z Maldaner da; Júnior, Gerson Cipriano; Liebano, Richard Eloin; Durigan, Joao Luiz Quagliotti

2018-02-02

Transcutaneous electrical nerve stimulation and interferential current have been widely used in clinical practice. However, a systematic review comparing their effects on pain relief has not yet been performed. To investigate the effects of transcutaneous electrical nerve stimulation and interferential current on acute and chronic pain. We use Pubmed, Embase, LILACS, PEDro and Cochrane Central Register of Controlled Trials as data sources. Two independent reviewers that selected studies according to inclusion criteria, extracted information of interest and verified the methodological quality of the studies made study selection. The studies were selected if transcutaneous electrical nerve stimulation and interferential current were used as treatment and they had pain as the main outcome, as evaluated by a visual analog scale. Secondary outcomes were the Western Ontario Macmaster and Rolland Morris Disability questionnaires, which were added after data extraction. Eight studies with a pooled sample of 825 patients were included. The methodological quality of the selected studies was moderate, with an average of six on a 0-10 scale (PEDro). In general, both transcutaneous electrical nerve stimulation and interferential current improved pain and functional outcomes without a statistical difference between them. Transcutaneous electrical nerve stimulation and interferential current have similar effects on pain outcome The low number of studies included in this meta-analysis indicates that new clinical trials are needed. Copyright © 2018 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Design and Evaluation on the Mobile Application of Transcutaneous Electrical Nerve Stimulation (TENS).

PubMed

Cheng, Ching-Lung; Lee, Li-Hui; Cheng, Yu-Ting

2017-01-01

This study aims to design a transcutaneous electrical nerve stimulation Application (TENS App) according to the suggestions from potential users. To the best of our knowledge, this is the first App including meridian and acupoints for TENS. After its development, there are eight participants recruited for evaluating the usability. Despite two out of eight users reporting that the typical TENS system requires lower cost and has better functionality than TENS App, the results show that almost seventy percent of participants have a better perception of TENS App on price, functionality, convenience, operational ability, and quality. However, participants still reported concerns about the safety issue of adopting TENS App. Therefore, for people who are the first time or unfamiliar with TENS App, instructions from occupational or physical therapists are recommended. We conclude that by using TENS App, users can not only use the portable electrotherapy devices at anyplace, but also reduce their outpatient visits.

Transcutaneous immunization with an outer membrane protein of Porphyromonas gingivalis without adjuvant elicits marked antibody responses.

PubMed

Koizumi, Y; Kurita-Ochiai, T; Yamamoto, M

2008-04-01

We have previously reported that specific immunoglobulin G (IgG) antibodies induced by transcutaneous immunization (TCI) with a 40-kDa outer membrane protein (40k-OMP) of Porphyromonas gingivalis, with cholera toxin (CT) as adjuvant, inhibited coaggregation by P. gingivalis. In this study, we further pursue the potential of the 40k-OMP as a transcutaneous vaccine. TCI of rats administered 40k-OMP elicited significant 40k-OMP-specific serum IgG and IgA, as well as salivary IgG antibody titers. Importantly, these antibody responses were induced without adjuvant. Thus, both serum and saliva antibody titers induced by TCI with the 40k-OMP alone were identical to those of 40k-OMP plus cholera toxin as adjuvant. The serum antibody responses induced by 40k-OMP persisted for more than 140 days. On the other hand, salivary IgG anti-40k-OMP antibodies were gradually decreased. Analysis of antibody-forming cells (AFCs) confirmed the antibody titers by detecting high numbers of 40k-OMP-specific IgG AFCs in spleen and cervical lymph node. Since 40k-OMP-specific IgG inhibited the coaggregation of P. gingivalis with Streptococcus gordonii, and the hemagglutinin activity of P. gingivalis, TCI with the 40k-OMP may be important as an adjuvant-free immunogen for the prevention of chronic periodontitis.

Mechanisms underpinning sympathetic nervous activity and its modulation using transcutaneous vagus nerve stimulation.

PubMed

Deuchars, Susan A; Lall, Varinder K; Clancy, Jennifer; Mahadi, Mohd; Murray, Aaron; Peers, Lucy; Deuchars, Jim

2018-03-01

What is the topic of this review? This review briefly considers what modulates sympathetic nerve activity and how it may change as we age or in pathological conditions. It then focuses on transcutaneous vagus nerve stimulation, a method of neuromodulation in autonomic cardiovascular control. What advances does it highlight? The review considers the pathways involved in eliciting the changes in autonomic balance seen with transcutaneous vagus nerve stimulation in relationship to other neuromodulatory techniques. The autonomic nervous system, consisting of the sympathetic and parasympathetic branches, is a major contributor to the maintenance of cardiovascular variables within homeostatic limits. As we age or in certain pathological conditions, the balance between the two branches changes such that sympathetic activity is more dominant, and this change in dominance is negatively correlated with prognosis in conditions such as heart failure. We have shown that non-invasive stimulation of the tragus of the ear increases parasympathetic activity and reduces sympathetic activity and that the extent of this effect is correlated with the baseline cardiovascular parameters of different subjects. The effects could be attributable to activation of the afferent branch of the vagus and, potentially, other sensory nerves in that region. This indicates that tragus stimulation may be a viable treatment in disorders where autonomic activity to the heart is compromised. © 2017 The Authors. Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

The combined effects of transcutaneous electrical nerve stimulation (TENS) and stretching on muscle hardness and pressure pain threshold.

PubMed

Karasuno, Hiroshi; Ogihara, Hisayoshi; Morishita, Katsuyuki; Yokoi, Yuka; Fujiwara, Takayuki; Ogoma, Yoshiro; Abe, Koji

2016-04-01

[Purpose] This study aimed to clarify the immediate effects of a combined transcutaneous electrical nerve stimulation and stretching protocol. [Subjects] Fifteen healthy young males volunteered to participate in this study. The inclusion criterion was a straight leg raising range of motion of less than 70 degrees. [Methods] Subjects performed two protocols: 1) stretching (S group) of the medial hamstrings, and 2) tanscutaneous electrical nerve stimulation (100 Hz) with stretching (TS group). The TS group included a 20-minute electrical stimulation period followed by 10 minutes of stretching. The S group performed 10 minutes of stretching. Muscle hardness, pressure pain threshold, and straight leg raising range of motion were analyzed to evaluate the effects. The data were collected before transcutaneous electrical nerve stimulation (T1), before stretching (T2), immediately after stretching (T3), and 10 minutes after stretching (T4). [Results] Combined transcutaneous electrical nerve stimulation and stretching had significantly beneficial effects on muscle hardness, pressure pain threshold, and straight leg raising range of motion at T2, T3, and T4 compared with T1. [Conclusion] These results support the belief that transcutaneous electrical nerve stimulation combined with stretching is effective in reducing pain and decreasing muscle hardness, thus increasing range of motion.

Clinical study and stability assessment of a novel transcutaneous influenza vaccination using a dissolving microneedle patch.

PubMed

Hirobe, Sachiko; Azukizawa, Hiroaki; Hanafusa, Takaaki; Matsuo, Kazuhiko; Quan, Ying-Shu; Kamiyama, Fumio; Katayama, Ichiro; Okada, Naoki; Nakagawa, Shinsaku

2015-07-01

Transcutaneous immunization (TCI) is an attractive vaccination method compared with conventional injectable vaccines because it is easier to administer without pain. We developed a dissolving microneedle patch (MicroHyala, MH) made of hyaluronic acid and showed that transcutaneous vaccination using MH induced a strong immune response against various antigens in mice. In the present study, we investigated the clinical safety and efficacy of a novel transcutaneous influenza vaccine using MH (flu-MH), which contains trivalent influenza hemagglutinins (15 μg each). Subjects of the TCI group were treated transcutaneously with flu-MH, and were compared with subjects who received subcutaneous injections of a solution containing 15 μg of each influenza antigen (SCI group). No severe local or systemic adverse events were detected in either group and immune responses against A/H1N1 and A/H3N2 strains were induced equally in the TCI and SCI groups. Moreover, the efficacy of the vaccine against the B strain in the TCI group was stronger than that in the SCI group. Influenza vaccination using MH is promising for practical use as an easy and effective method to replace conventional injections systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of assessment site in measuring transcutaneous bilirubin

PubMed Central

da Conceição, Cristiane Maria; Dornaus, Maria Fernanda Pellegrino da Silva; Portella, Maria Aparecida; Deutsch, Alice D'Agostini; Rebello, Celso Moura

2014-01-01

ABSTRACT Objective: To investigate the influence of the site of measurement of transcutaneous bilirubin (forehead or sternum) in reproducibility of results as compared to plasma bilirubin. Methods: A cohort study including 58 term newborns with no hemolytic disease. Transcutaneous measurements were performed on the forehead (halfway between the headline and the glabella, from the left toward the right side, making consecutive determinations, one-centimeter apart) and the sternum (five measurements, from the suprasternal notch to the xiphoid process with consecutive determinations, one-centimeter apart) using Bilicheck® (SpectRx Inc, Norcross, Georgia, USA). The correlation and agreement between both methods and plasma bilirubin were calculated. Results: There was a strong linear correlation between both determinations of serum bilirubin at the forehead and sternum (r=0.704; p<0.01 and r=0.653; p<0.01, respectively). There was correspondence of the mean values of transcutaneous bilirubin measured on the sternum (9.9±2.2mg/dL) compared to plasma levels (10.2±1.7mg/dL), but both differ from the values measured on the forehead (8.6±2.0mg/dL), p<0.05. Conclusion: In newborn term infants with no hemolytic disease, measuring of transcutaneous bilirubin on the sternum had higher accuracy as compared to serum bilirubin measurement on the forehead. PMID:24728239

Analysis, design, and control of a transcutaneous power regulator for artificial hearts.

PubMed

Qianhong Chen; Siu Chung Wong; Tse, C K; Xinbo Ruan

2009-02-01

Based on a generic transcutaneous transformer model, a remote power supply using a resonant topology for use in artificial hearts is analyzed and designed for easy controllability and high efficiency. The primary and secondary windings of the transcutaneous transformer are positioned outside and inside the human body, respectively. In such a transformer, the alignment and gap may change with external positioning. As a result, the coupling coefficient of the transcutaneous transformer is also varying, and so are the two large leakage inductances and the mutual inductance. Resonant-tank circuits with varying resonant-frequency are formed from the transformer inductors and external capacitors. For a given range of coupling coefficients, an operating frequency corresponding to a particular coupling coefficient can be found, for which the voltage transfer function is insensitive to load. Prior works have used frequency modulation to regulate the output voltage under varying load and transformer coupling. The use of frequency modulation may require a wide control frequency range which may extend well above the load insensitive frequency. In this paper, study of the input-to-output voltage transfer function is carried out, and a control method is proposed to lock the switching frequency at just above the load insensitive frequency for optimized efficiency at heavy loads. Specifically, operation at above resonant of the resonant circuits is maintained under varying coupling-coefficient. Using a digital-phase-lock-loop (PLL), zero-voltage switching is achieved in a full-bridge converter which is also programmed to provide output voltage regulation via pulsewidth modulation (PWM). A prototype transcutaneous power regulator is built and found to to perform excellently with high efficiency and tight regulation under variations of the alignment or gap of the transcutaneous transformer, load and input voltage.

Rearfoot Transcutaneous Oximetry is a Useful Tool to Highlight Ischemia of the Heel

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

Izzo, Valentina, E-mail: valentina-izzo@virgilio.it; Meloni, Marco, E-mail: meloni.marco@libero.it; Fabiano, Sebastiano, E-mail: sebas575@yahoo.it

PurposeTo demonstrate the usefulness of rearfoot transcutaneous oximetry to assess the peripheral arterial disease in diabetic patients with heel ulcer.MethodsFrom our database of 550 critical limb ischemia diabetic patients followed after a percutaneous transluminal angioplasty, we have selected patients with below the knee arterial disease. Patients were grouped according to the dorsal transcutaneous oximetry value (Group A < 30 mmHg; Group B ≥ 30 mmHg). Patients of Group B had a second oximetry performed at the rearfoot, close to the lesion localized in all cases at the heel. Finally, the analysis of the arterial pattern disease has been done.ResultsWe selected 191 patients: Group A (151 patients),more » dorsal transcutaneous oximetry of 11.8 ± 0.7 mmHg; Group B (40 patients), dorsal transcutaneous oximetry of 44.2 ± 10.1 mmHg. In Group B, rearfoot oximetry was 20.5 ± 5 mmHg, significantly lower than dorsal oximetry (p = 0.0179). The anterior tibial artery was involved in all patients of Group A. In Group B, the anterior tibial artery was involved in 15 subjects and never alone; the posterior tibial artery was involved in 20 subjects and in 11 cases alone. The peroneal artery was affected in 20 subjects and in 14 patients alone.ConclusionWhen a heel lesion is present and the transcutaneous oximetry recorded on the dorsum of the foot does not confirm the presence of critical limb ischemia (not ≤30 mmHg), a second oximetry recorded on the rearfoot is useful to point out ischemia of the peroneal artery and/or of the posterior tibial artery.« less

Optimization of antitumor treatment conditions for transcutaneous CO2 application: An in vivo study.

PubMed

Ueha, Takeshi; Kawamoto, Teruya; Onishi, Yasuo; Harada, Risa; Minoda, Masaya; Toda, Mitsunori; Hara, Hitomi; Fukase, Naomasa; Kurosaka, Masahiro; Kuroda, Ryosuke; Akisue, Toshihiro; Sakai, Yoshitada

2017-06-01

Carbon dioxide (CO2) therapy can be applied to treat a variety of disorders. We previously found that transcutaneous application of CO2 with a hydrogel decreased the tumor volume of several types of tumors and induced apoptosis via the mitochondrial pathway. However, only one condition of treatment intensity has been tested. For widespread application in clinical antitumor therapy, the conditions must be optimized. In the present study, we investigated the relationship between the duration, frequency, and treatment interval of transcutaneous CO2 application and antitumor effects in murine xenograft models. Murine xenograft models of three types of human tumors (breast cancer, osteosarcoma, and malignant fibrous histiocytoma/undifferentiated pleomorphic sarcoma) were used to assess the antitumor effects of transcutaneous CO2 application of varying durations, frequencies, and treatment intervals. In all human tumor xenografts, apoptosis was significantly induced by CO2 treatment for ≥10 min, and a significant decrease in tumor volume was observed with CO2 treatments of >5 min. The effect on tumor volume was not dependent on the frequency of CO2 application, i.e., twice or five times per week. However, treatment using 3- and 4-day intervals was more effective at decreasing tumor volume than treatment using 2- and 5-day intervals. The optimal conditions of transcutaneous CO2 application to obtain the best antitumor effect in various tumors were as follows: greater than 10 min per application, twice per week, with 3- and 4-day intervals, and application to the site of the tumor. The results suggest that this novel transcutaneous CO2 application might be useful to treat primary tumors, while mitigating some side effects, and therefore could be safe for clinical trials.

Assessment of patient support surfaces: principle, practice and limitations.

PubMed

Rithalia, S

2005-01-01

Pressure ulcers cause great pain and suffering to patients as well as unnecessary strain on nursing staff. Their treatment is both costly and time consuming. Every effort therefore should be directed towards their prevention. Understanding of the aetiology of pressure ulcers is still incomplete and assessment of devices aimed at prevention is difficult. Over the years, numerous parameters, including interface pressure and transcutaneous blood gas measurements, have been used to evaluate mattresses and cushions. However, the quality of the data gathered is variable and its clinical interpretation remains unsatisfactory. It could be said that the science of evaluation of support surfaces is still at a formative stage, as clinical validation of many of the approaches has yet to be carried out.

Non-invasive measurement of the temperature rise in tissue surrounding a kidney stone subjected to ultrasonic propulsion.

PubMed

Oweis, Ghanem F; Dunmire, Barbrina L; Cunitz, Bryan W; Bailey, Michael R

2015-01-01

Transcutaneous focused ultrasound (US) is used to propel kidney stones using acoustic radiation force. It is important to estimate the level of heating generated at the stone/tissue interface for safety assessment. An in-vitro experiment is conducted to measure the temperature rise in a tissue-mimicking phantom with an embedded artificial stone and subjected to a focused beam from an imaging US array. A novel optical-imaging-based thermometry method is described using an optically clear tissue phantom. Measurements are compared to the output from a fine wire thermocouple placed on the stone surface. The optical method has good sensitivity, and it does not suffer from artificial viscous heating typically observed with invasive probes and thermocouples.

Transcutaneous vagus nerve stimulation (tVNS) enhances conflict-triggered adjustment of cognitive control.

PubMed

Fischer, Rico; Ventura-Bort, Carlos; Hamm, Alfons; Weymar, Mathias

2018-04-24

Response conflicts play a prominent role in the flexible adaptation of behavior as they represent context-signals that indicate the necessity for the recruitment of cognitive control. Previous studies have highlighted the functional roles of the affectively aversive and arousing quality of the conflict signal in triggering the adaptation process. To further test this potential link with arousal, participants performed a response conflict task in two separate sessions with either transcutaneous vagus nerve stimulation (tVNS), which is assumed to activate the locus coeruleus-noradrenaline (LC-NE) system, or with neutral sham stimulation. In both sessions the N2 and P3 event-related potentials (ERP) were assessed. In line with previous findings, conflict interference, the N2 and P3 amplitude were reduced after conflict. Most importantly, this adaptation to conflict was enhanced under tVNS compared to sham stimulation for conflict interference and the N2 amplitude. No effect of tVNS on the P3 component was found. These findings suggest that tVNS increases behavioral and electrophysiological markers of adaptation to conflict. Results are discussed in the context of the potentially underlying LC-NE and other neuromodulatory (e.g., GABA) systems. The present findings add important pieces to the understanding of the neurophysiological mechanisms of conflict-triggered adjustment of cognitive control.

Measuring Tissue Perfusion During Pressure Relief Maneuvers: Insights Into Preventing Pressure Ulcers

PubMed Central

Makhsous, Mohsen; Priebe, Michael; Bankard, James; Rowles, Diana; Zeigler, Mary; Chen, David; Lin, Fang

2007-01-01

Background/Objective: To study the effect on tissue perfusion of relieving interface pressure using standard wheelchair pushups compared with a mechanical automated dynamic pressure relief system. Design: Repeated measures in 2 protocols on 3 groups of subjects. Participants: Twenty individuals with motor-complete paraplegia below T4, 20 with motor-complete tetraplegia, and 20 able-bodied subjects. Methods: Two 1-hour sitting protocols: dynamic protocol, sitting configuration alternated every 10 minutes between a normal sitting configuration and an off-loading configuration; wheelchair pushup protocol, normal sitting configuration with standard wheelchair pushup once every 20 minutes. Main Outcome Measures: Transcutaneous partial pressures of oxygen and carbon dioxide measured from buttock overlying the ischial tuberosity and interface pressure measured at the seat back and buttocks. Perfusion deterioration and recovery times were calculated during changes in interface pressures. Results: In the off-loading configuration, concentrated interface pressure during the normal sitting configuration was significantly diminished, and tissue perfusion was significantly improved. Wheelchair pushups showed complete relief of interface pressure but incomplete recovery of tissue perfusion. Conclusions: Interface pressure analysis does not provide complete information about the effectiveness of pressure relief maneuvers. Measures of tissue perfusion may help establish more effective strategies. Relief achieved by standard wheelchair pushups may not be sufficient to recover tissue perfusion compromised during sitting; alternate maneuvers may be necessary. The dynamic seating system provided effective pressure relief with sustained reduction in interface pressure adequate for complete recovery of tissue perfusion. Differences in perfusion recovery times between subjects with spinal cord injury (SCI) and controls raise questions about the importance of changes in vascular responses to pressure after SCI. PMID:18092567

Electrophysiological evidence for the antinociceptive effect of transcutaneous electrical stimulation on mechanically evoked responsiveness of dorsal horn neurons in neuropathic rats.

PubMed

Leem, J W; Park, E S; Paik, K S

1995-06-16

Using a rat model of peripheral neuropathy induced by a tight ligation of L5-6 spinal nerves, the effects of transcutaneous electrical stimulation on the mechanical responses of wide dynamic range (WDR) dorsal horn neurons were investigated. The responses of the WDR neurons to both the brush and pinch stimuli were found to be enhanced in the neuropathic rats compared to those in the normal rats. These enhanced responses were depressed by low-frequency and high-intensity transcutaneous electrical stimulation (2 Hz, 4-5 mA) applied to the somatic receptive field. The durations of the depressive effects on the brush responses ranged between 30 and 45 min and those on the pinch responses were 60-90 min. These results imply that the transcutaneous electrical stimulation used here produces an antinociceptive effect via a depressive action on the enhanced mechanical responsiveness of the spinal neurons in this rat model of peripheral neuropathy.

Laser-acoustic transcutaneous drug delivery: A new trend in administration of drugs

NASA Astrophysics Data System (ADS)

Zharov, Vladimir P.; Latyshev, Alexei S.

1999-03-01

This work deals with the principles of transcutaneous drug delivery technique which uses optoacoustic (OA) effect. Laser OA impregnation, enhanced laser OA impregnation, simple laser and laser OA injections are presented. Drug impregnation mathematical model and preliminary experiments on laser injection are described.

Development of a transcutaneous blood-constituent monitoring method using a suction effusion fluid collection technique and an ion-sensitive field-effect transistor glucose sensor.

PubMed

Ito, N; Kayashima, S; Kimura, J; Kuriyama, T; Arai, T; Kikuchi, M; Nagata, N

1994-05-01

The paper describes a method for the transcutaneous monitoring of blood constituents. It combines the use of a suction effusion fluid (SEF) collecting technique with a silicon on sapphire/ion-sensitive field-effect transistor (SOS/ISFET) biosensor. SEF is directly collected by a weak evacuation through skin from which the stratum corneum has been removed. An SEF collecting cell with a stainless-steel mesh at the bottom is kept in a weak vacuum condition, and SEF is sucked up through the mesh and deposited in a reservoir above. An ISFET glucose sensor is able to detect glucose concentrations in very small SEF samples through the use of two small ISFETs and an immobilised enzyme membrane. The reliability of transcutaneously obtained SEF was first confirmed in an experiment using rabbits. A clinical analyser was used to determine levels of glucose, urea nitrogen and creatinine in SEF obtained transcutaneously; these results are compared with results obtained by the same analyser directly from sera. The ISFET glucose sensor was successfully tested on human subjects for the monitoring of blood glucose levels. During these tests, glucose level changes in the SEF followed actual blood glucose level changes with a slight time delay. Results suggest the feasibility of non-invasive, transcutaneous monitoring of low molecular weight substances in the blood without the use of ordinary blood sampling.

Improved Walking Claudication Distance with Transcutaneous Electrical Nerve Stimulation: An Old Treatment with a New Indication in Patients with Peripheral Artery Disease.

PubMed

Labrunée, Marc; Boned, Anne; Granger, Richard; Bousquet, Marc; Jordan, Christian; Richard, Lisa; Garrigues, Damien; Gremeaux, Vincent; Sénard, Jean-Michel; Pathak, Atul; Guiraud, Thibaut

2015-11-01

The aim of this study was to determine whether 45 mins of transcutaneous electrical nerve stimulation before exercise could delay pain onset and increase walking distance in peripheral artery disease patients. After a baseline assessment of the walking velocity that led to pain after 300 m, 15 peripheral artery disease patients underwent four exercise sessions in a random order. The patients had a 45-min transcutaneous electrical nerve stimulation session with different experimental conditions: 80 Hz, 10 Hz, sham (presence of electrodes without stimulation), or control with no electrodes, immediately followed by five walking bouts on a treadmill until pain occurred. The patients were allowed to rest for 10 mins between each bout and had no feedback concerning the walking distance achieved. Total walking distance was significantly different between T10, T80, sham, and control (P < 0.0003). No difference was observed between T10 and T80, but T10 was different from sham and control. Sham, T10, and T80 were all different from control (P < 0.001). There was no difference between each condition for heart rate and blood pressure. Transcutaneous electrical nerve stimulation immediately before walking can delay pain onset and increase walking distance in patients with class II peripheral artery disease, with transcutaneous electrical nerve stimulation of 10 Hz being the most effective.

Association between gestational age and bovine fetal characteristics measured by transcutaneous ultrasound over the right flank of the dairy cow.

PubMed

Hunnam, J C; Parkinson, T J; Lopez-Villalobos, N; McDougall, S

2009-09-01

To determine bovine fetal characteristics significantly associated with increasing gestational age as measured via transcutaneous ultrasonography over the right flank. The length of gestation at date of pregnancy diagnosis via transcutaneous and transrectal ultrasonography was determined for 224 dairy cattle by estimation from subsequent calving dates. A separate dataset was created for each measurable fetal characteristic (i.e. thoracic diameter, abdominal diameter, umbilical diameter, placentome length and placentome height) and risk factors significantly associated with gestational age at pregnancy diagnosis within each dataset, including the fetal characteristic, were identified. Abdominal diameter was the most frequently observed fetal characteristic and thoracic diameter was the least. Gestational age at pregnancy diagnosis (d) was significantly associated with fetal thoracic diameter (P < 0.01), abdominal diameter (P < 0.01) and umbilical diameter (P = 0.02) when measured via transcutaneous ultrasound. Within each model, sire breed, dam breed, dam age and/or calf sex were also significantly associated with gestational age. Gestational age at pregnancy diagnosis was not significantly associated with either placentome height or length (P > 0.05). Fetal thoracic diameter, abdominal diameter and umbilical diameter were found to be significantly associated with gestational age between approximate days 73 to 190 of gestation. Transcutaneous ultrasonography may prove a useful method of estimating gestational age in the absence of accurate breeding records.

Transcutaneous Electrical Nerve Stimulation: Research Update.

ERIC Educational Resources Information Center

Johns, Florene Carnicelli

Currently, research is being performed in the area of nonsurgical and nonchemical means for influencing the body's threshold for pain. Today, transcutaneous electrical nerve stimulation (TENS) is being widely used for this purpose. Application of this treatment can be confusing, however, because determining such things as selection of the proper…

Measuring Transcutaneous Oxygenation to Validate the Duration Required to Achieve Electrode Equilibration.

PubMed

Chiang, Nathaniel; Jain, Jitendra K; Sleigh, Jamie; Vasudevan, Thodur

2018-06-01

The transcutaneous oxygenation measurement (TCOM) system is useful in assessing tissue viability. There are no clear recommendations regarding the duration required for the electrode to equilibrate and reliably evaluate tissue oxygenation values. The objective of this study was to validate the duration required to achieve electrode equilibration in a clinical setting. Minute-by-minute recordings using TCOM (TCOM3; Radiometer Medical ApS, Brønshøj, Copenhagen) were obtained for 82 limbs in 50 participants. Twenty-five limbs were in patients with peripheral vascular disease; 30 were in patients with no known peripheral vascular disease; and 27 were in healthy volunteers. Transcutaneous partial pressure of oxygen and carbon dioxide (TcPO2 and TcPCO2) were recorded over a 15-minute period. Participants' TcPO2 decreased and TcPCO2 increased over time. Both changed in a nonlinear fashion, eventually settling at an "equilibrium" where the measurements became stable. The difference in proportional change of TcPO2 between minutes 14 and 15 was 0.8%, and for TcPCO2was 2.9%. Changes in TCOM measurements over time were similar among the 3 groups. This is the first study to target minute-by-minute variation in TcPO2 and TcPCO2 measurements. Recording for a minimum of 15 minutes allows a reliable period for the TCOM electrode to equilibrate to record absolute values and determine wound healing potential.

A multi-pad electrode based functional electrical stimulation system for restoration of grasp

PubMed Central

2012-01-01

Background Functional electrical stimulation (FES) applied via transcutaneous electrodes is a common rehabilitation technique for assisting grasp in patients with central nervous system lesions. To improve the stimulation effectiveness of conventional FES, we introduce multi-pad electrodes and a new stimulation paradigm. Methods The new FES system comprises an electrode composed of small pads that can be activated individually. This electrode allows the targeting of motoneurons that activate synergistic muscles and produce a functional movement. The new stimulation paradigm allows asynchronous activation of motoneurons and provides controlled spatial distribution of the electrical charge that is delivered to the motoneurons. We developed an automated technique for the determination of the preferred electrode based on a cost function that considers the required movement of the fingers and the stabilization of the wrist joint. The data used within the cost function come from a sensorized garment that is easy to implement and does not require calibration. The design of the system also includes the possibility for fine-tuning and adaptation with a manually controllable interface. Results The device was tested on three stroke patients. The results show that the multi-pad electrodes provide the desired level of selectivity and can be used for generating a functional grasp. The results also show that the procedure, when performed on a specific user, results in the preferred electrode configuration characteristics for that patient. The findings from this study are of importance for the application of transcutaneous stimulation in the clinical and home environments. PMID:23009589

Novel diode-based laser system for combined transcutaneous monitoring and computer-controlled intermittent treatment of jaundiced neonates

NASA Astrophysics Data System (ADS)

Hamza, Mostafa; El-Ahl, Mohammad H. S.; Hamza, Ahmad M.

2001-06-01

The high efficacy of laser phototherapy combined with transcutaneous monitoring of serum bilirubin provides optimum safety for jaundiced infants from the risk of bilirubin encephalopathy. In this paper the authors introduce the design and operating principles of a new laser system that can provide simultaneous monitoring and treatment of several jaundiced babies at one time. The new system incorporates diode-based laser sources oscillating at selected wavelengths to achieve both transcutaneous differential absorption measurements of bilirubin concentration in addition to the computer controlled intermittent laser therapy through a network of optical fibers. The detailed description and operating characteristics of this system are presented.

Transcutaneous electrical neurostimulation in musculoskeletal pain of acute spinal cord injuries.

PubMed

Richardson, R R; Meyer, P R; Cerullo, L J

1980-01-01

Cervical, thoracic, thoracolumbar, and lumbar fractures associated with physiologic complete or incomplete spinal cord injuries frequently have severe soft-tissue injury as well as severe pain associated with the site or area of injury. Transcutaneous electrical neurostimulation has proved effective in the treatment of various causes of severe acute and chronic intractable pains. We applied this modality to a group of 20 patients who had acute spinal cord injuries and pain associated with severe, extensive soft-tissue injury. Its advantages include ease of application, lack of major complications, increased intestinal peristalsis, and avoidance of narcotic analgesic medications. It also produced significant (greater than 50%) pain relief in 75% of patients treated by transcutaneous electrical neurostimulation.

42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

Code of Federal Regulations, 2010 CFR

2010-10-01

... nerve stimulators (TENS). 414.232 Section 414.232 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Special payment rules for transcutaneous electrical nerve stimulators (TENS). (a) General payment rule. Except as provided in paragraph (b) of this section, payment for TENS is made on a purchase basis with...

Increased transcutaneous oxygen tension in the skin dorsum over the foot in patients with diabetic foot disease in response to the topical use of an emulsion of hyperoxygenated Fatty acids.

PubMed

Lázaro-Martínez, J L; Sánchez-Ríos, J P; García-Morales, E; Cecilia-Matilla, A; Segovia-Gómez, T

2009-12-01

The aim of this study was to examine changes in the skin over the feet of patients with diabetic foot syndrome after local application of a product containing hyperoxygenated fatty acids (HOFAs) by measuring transcutaneous oxygen. In 64 patients, transcutaneous oxygen pressure (TcPo(2)) was measured on days 0, 7, 30, 60, and 90 of the study. Foot skin dryness, shedding, and skin color were also assessed using a clinical score. The patients were grouped on the basis of initial levels of transcutaneous oxygen; group 1 comprised patients with TcPo( 2) >30 mm Hg and group 2 comprised patients with TcPo(2) <30 mm Hg on the skin over the dorsum of the feet. Increases in local oxygenation values were observed at a local level in group 2 patients after 30 days of treatment. Skin trophism showed clinical improvement in all patients and these observations may be attributed to improved local microcirculation.

A urodynamic study of surface neuromodulation versus sham in detrusor instability and sensory urgency.

PubMed

Bower, W F; Moore, K H; Adams, R D; Shepherd, R

1998-12-01

We studied the effect of surface neuromodulation on cystometric pressure and volume parameters in women with detrusor instability or sensory urgency. Electrical current was delivered to the suprapubic region and third sacral foramina via a transcutaneous electrical nerve stimulator with sham neuromodulation control. A consecutive series of women with proved detrusor instability or sensory urgency were randomized to 3 surface neuromodulation groups. Volume and pressure parameters were the main outcomes of transcutaneous electrical nerve stimulation applied during second cystometric fill. Sham transcutaneous electrical nerve stimulation did not alter the outcome measures. However, neuromodulation delivered across the suprapubic and sacral skin effected a reduction in mean maximum height of detrusor contraction. A current which inhibits motor activity was not superior to that which inhibits sensory perception in reducing detrusor pressure. Response in sensory urgency was poor. Results from our sham controlled study suggest that short-term surface neuromodulation via transcutaneous electrical nerve stimulation may have a role in the treatment of detrusor instability. Future studies must examine the clinical effect of long-term surface neuromodulation.

Advances in selective activation of muscles for non-invasive motor neuroprostheses.

PubMed

Koutsou, Aikaterini D; Moreno, Juan C; Del Ama, Antonio J; Rocon, Eduardo; Pons, José L

2016-06-13

Non-invasive neuroprosthetic (NP) technologies for movement compensation and rehabilitation remain with challenges for their clinical application. Two of those major challenges are selective activation of muscles and fatigue management. This review discusses how electrode arrays improve the efficiency and selectivity of functional electrical stimulation (FES) applied via transcutaneous electrodes. In this paper we review the principles and achievements during the last decade on techniques for artificial motor unit recruitment to improve the selective activation of muscles. We review the key factors affecting the outcome of muscle force production via multi-pad transcutaneous electrical stimulation and discuss how stimulation parameters can be set to optimize external activation of body segments. A detailed review of existing electrode array systems proposed by different research teams is also provided. Furthermore, a review of the targeted applications of existing electrode arrays for control of upper and lower limb NPs is provided. Eventually, last section demonstrates the potential of electrode arrays to overcome the major challenges of NPs for compensation and rehabilitation of patient-specific impairments.

The effects of high-frequency transcranial magnetic stimulation combined with transcutaneous electrical stimulation in a severe stroke patient.

PubMed

Koyama, Soichiro; Tanabe, Shigeo; Takeda, Kazuya; Warashina, Hiroaki; Sakurai, Hiroaki; Kanada, Yoshikiyo; Okumura, Ryuji; Shinoda, Jun; Nagata, Junji; Kanno, Tetsuo

2012-10-12

The case report describes the effects of 5 Hz repetitive transcranial magnetic stimulation (rTMS) combined with transcutaneous electrical stimulation (TES) in a patient with severe stroke. The patient was a 69-year-old male who was affected by a left middle cerebral artery infarction. The patient had no movement in his right hand. To assess the effects, cerebral blood flow and motor function were measured before and after treatment. This treatment delivered rTMS over the affected M1 with TES at the paretic wrist extensor muscles for 10 days. The regional cerebral blood flow (rCBF) in the entire brain was measured by positronemission tomography. To evaluate the motor function, the Fugl-Meyer assessment (FMA) was used. After treatment, the rCBF was increased (except for the stimulated region), and the FMA score was slightly improved. These results suggest the potential therapeutic use of rTMS combined with TES for recovery in severe stroke.

Comparison of the Effectiveness of Transcutaneous Electrical Nerve Stimulation and Interferential Therapy on the Upper Trapezius in Myofascial Pain Syndrome: A Randomized Controlled Study.

PubMed

Dissanayaka, Thusharika Dilrukshi; Pallegama, Ranjith Wasantha; Suraweera, Hilari Justus; Johnson, Mark I; Kariyawasam, Anula Padma

2016-09-01

The aim of this study was to compare the effectiveness of transcutaneous electrical nerve stimulation and interferential therapy (IFT) both in combination with hot pack, myofascial release, active range of motion exercise, and a home exercise program on myofascial pain syndrome patients with upper trapezius myofascial trigger point. A total of 105 patients with an upper trapezius myofascial trigger point were recruited to this single-blind randomized controlled trial. Following random allocation of patients to three groups, three therapeutic regimens-control-standard care (hot pack, active range of motion exercises, myofascial release, and a home exercise program with postural advice), transcutaneous electrical nerve stimulation-standard care and IFT-standard care-were administered eight times during 4 wks at regular intervals. Pain intensity and cervical range of motions (cervical extension, lateral flexion to the contralateral side, and rotation to the ipsilateral side) were measured at baseline, immediately after the first treatment, before the eighth treatment, and 1 wk after the eighth treatment. Immediate and short-term improvements were marked in the transcutaneous electrical nerve stimulation group (n = 35) compared with the IFT group (n = 35) and the control group (n = 35) with respect to pain intensity and cervical range of motions (P < 0.05). The IFT group showed significant improvement on these outcome measurements than the control group did (P < 0.05). Transcutaneous electrical nerve stimulation with standard care facilitates recovery better than IFT does in the same combination.

Assessment of Wound Therapy Systems.

DTIC Science & Technology

1983-10-06

electrodes in vinyl foam (mfr: Healthco) (for potential measurements), sticky carbon-impregnated pads (commonly used * for transcutaneous electrical nerve...improved product is a conductive material, applied to the target surface as a liquid (in which an electrode can be embedded); this liquid material then gels... conducted with two grades of collagen hydrolysate (gelatins) which have been cross-linked in situ from water solu- tion. This work clearly shows that stable

Deep tissue afferents, but not cutaneous afferents, mediate transcutaneous electrical nerve stimulation-Induced antihyperalgesia.

PubMed

Radhakrishnan, Rajan; Sluka, Kathleen A

2005-10-01

In this study we investigated the involvement of cutaneous versus knee joint afferents in the antihyperalgesia produced by transcutaneous electrical nerve stimulation (TENS) by differentially blocking primary afferents with local anesthetics. Hyperalgesia was induced in rats by inflaming one knee joint with 3% kaolin-carrageenan and assessed by measuring paw withdrawal latency to heat before and 4 hours after injection. Skin surrounding the inflamed knee joint was anesthetized using an anesthetic cream (EMLA). Low (4 Hz) or high (100 Hz) frequency TENS was then applied to the anesthetized skin. In another group, 2% lidocaine gel was injected into the inflamed knee joint, and low or high frequency TENS was applied. Control experiments were done using vehicles. In control and EMLA groups, both low and high frequency TENS completely reversed hyperalgesia. However, injection of lidocaine into the knee joint prevented antihyperalgesia produced by both low and high frequency TENS. Recordings of cord dorsum potentials showed that both low and high frequency TENS at sensory intensity activates only large diameter afferent fibers. Increasing intensity to twice the motor threshold recruits Adelta afferent fibers. Furthermore, application of EMLA cream to the skin reduces the amplitude of the cord dorsum potential by 40% to 70% for both high and low frequency TENS, confirming a loss of large diameter primary afferent input after EMLA is applied to the skin. Thus, inactivation of joint afferents, but not cutaneous afferents, prevents the antihyperalgesia effects of TENS. We conclude that large diameter primary afferent fibers from deep tissue are required and that activation of cutaneous afferents is not sufficient for TENS-induced antihyperalgesia. Transcutaneous electrical nerve stimulation (TENS) is an accepted clinical modality used for pain relief. It is generally believed that TENS analgesia is caused mainly by cutaneous afferent activation. In this study by differentially blocking cutaneous and deep tissue primary afferents, we show that the activation of large diameter primary afferents from deep somatic tissues, and not cutaneous afferents, are pivotal in causing TENS analgesia.

21 CFR 874.3950 - Transcutaneous air conduction hearing aid system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Transcutaneous air conduction hearing aid system. 874.3950 Section 874.3950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Conduction Hearing Aid System (TACHAS); Guidance for Industry and FDA.” See § 874.1 for the availability of...

Effect of Transcutaneous Electrical Nerve Stimulation on Sensation Thresholds in Patients with Painful Diabetic Neuropathy: An Observational Study

ERIC Educational Resources Information Center

Moharic, Metka

2010-01-01

Transcutaneous electrical nerve stimulation (TENS) is one of the therapies for painful neuropathy. Its analgesic mechanisms probably involve the gate control theory, the physiological block and the endogenous pain inhibitory system. The aim of the study was to determine whether TENS improves small fibre function diminished because of painful…

Validating in vivo Raman spectroscopy of bone in human subjects

NASA Astrophysics Data System (ADS)

Esmonde-White, Francis W. L.; Morris, Michael D.

2013-03-01

Raman spectroscopy can non-destructively measure properties of bone related to mineral density, mineral composition, and collagen composition. Bone properties can be measured through the skin in animal and human subjects, but correlations between the transcutaneous and exposed bone measurements have only been reported for human cadavers. In this study, we examine human subjects to collect measurements transcutaneously, on surgically exposed bone, and on recovered bone fragments. This data will be used to demonstrate in vivo feasibility and to compare transcutaneous and exposed Raman spectroscopy of bone. A commercially available Raman spectrograph and optical probe operating at 785 nm excitation are used for the in vivo measurements. Requirements for applying Raman spectroscopy during a surgery are also discussed.

Transcutaneous periorbital electrical stimulation in the treatment of dry eye.

PubMed

Pedrotti, Emilio; Bosello, Francesca; Fasolo, Adriano; Frigo, Anna C; Marchesoni, Ivan; Ruggeri, Alfredo; Marchini, Giorgio

2017-06-01

To evaluate efficacy and safety of transcutaneous application of electrical current on symptoms and clinical signs of dry eye (DE). 27 patients with DE underwent transcutaneous electrostimulation with electrodes placed onto the periorbital region of both eyes and manual stimulation with a hand-piece conductor moved by the operator. Each patient underwent 12 sessions of 22 min spread over 2 months, two sessions per week in the first month and one session per week in the second month. Ocular Surface Disease Index (OSDI) questionnaire, tear break-up time (TBUT), fluorescein staining of the cornea, Schirmer I test and adverse events were evaluated at baseline, at end of treatment and at 6 and 12 months. OSDI improved from 43.0±19.2 at baseline to 25.3±22.1 at end of treatment (mean±SD, p=0.001). These effects were substantially maintained at 6-month and 12-month follow-up evaluations. Improvement of the values of TBUT was recorded for the right eye at the end of treatment (p=0.003) and found in the left eye after 12 months (p=0.02). The Oxford scores changed in both eyes at the end of treatment and at the 6-month evaluation (p<0.001), and in the right eye at the 12-month evaluation (p=0.035). Schirmer I improved significantly at the end of treatment in the left eye (p=0.001) and in both eyes at the 12-month evaluation (p=0.004 and p=0.039 for the left and right eye, respectively). A significant reduction of the use of tear substitutes was found at the end of treatment (p=0.003), and was maintained during the follow-up (p<0.001).No complications occurred and patients found the treatment satisfying. Transcutaneous electrical stimulation was shown to improve DE, both subjectively and objectively, without any adverse effects and has the potential to enlarge the armamentarium for treating DE. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Simultaneous estimation of transcutaneous bilirubin, hemoglobin, and melanin based on diffuse reflectance spectroscopy

NASA Astrophysics Data System (ADS)

Nishidate, Izumi; Abdul, Wares MD.; Ohtsu, Mizuki; Nakano, Kazuya; Haneishi, Hideaki

2018-02-01

We propose a method to estimate transcutaneous bilirubin, hemoglobin, and melanin based on the diffuse reflectance spectroscopy. In the proposed method, the Monte Carlo simulation-based multiple regression analysis for an absorbance spectrum in the visible wavelength region (460-590 nm) is used to specify the concentrations of bilirubin (Cbil), oxygenated hemoglobin (Coh), deoxygenated hemoglobin (Cdh), and melanin (Cm). Using the absorbance spectrum calculated from the measured diffuse reflectance spectrum as a response variable and the extinction coefficients of bilirubin, oxygenated hemoglobin, deoxygenated hemoglobin, and melanin, as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of bilirubin, oxygenated hemoglobin, deoxygenated hemoglobin, and melanin, are then determined from the regression coefficients using conversion vectors that are numerically deduced in advance by the Monte Carlo simulations for light transport in skin. Total hemoglobin concentration (Cth) and tissue oxygen saturation (StO2) are simply calculated from the oxygenated hemoglobin and deoxygenated hemoglobin. In vivo animal experiments with bile duct ligation in rats demonstrated that the estimated Cbil is increased after ligation of bile duct and reaches to around 20 mg/dl at 72 h after the onset of the ligation, which corresponds to the reference value of Cbil measured by a commercially available transcutaneous bilirubin meter. We also performed in vivo experiments with rats while varying the fraction of inspired oxygen (FiO2). Coh and Cdh decreased and increased, respectively, as FiO2 decreased. Consequently, StO2 was dramatically decreased. The results in this study indicate potential of the method for simultaneous evaluation of multiple chromophores in skin tissue.

Feasibility study of Transcutaneous Electrical Nerve Stimulation (TENS) for cancer bone pain.

PubMed

Bennett, Michael I; Johnson, Mark I; Brown, Sarah R; Radford, Helen; Brown, Julia M; Searle, Robert D

2010-04-01

This multicenter study assessed the feasibility of conducting a phase III trial of transcutaneous electrical nerve stimulation (TENS) in patients with cancer bone pain recruited from palliative care services. Eligible patients received active and placebo TENS for 1 hour at site of pain in a randomized crossover design; median interval between applications 3 days. Responses assessed at 30 and 60 minutes included numerical and verbal ratings of pain at rest and on movement, and pain relief. Recruitment, tolerability, adverse events, and effectiveness of blinding were also evaluated. Twenty-four patients were randomised and 19 completed both applications. The intervention was well tolerated. Five patients withdrew: 3 due to deteriorating performance status, and 2 due to increased pain (1 each following active and placebo TENS). Confidence interval estimation around the differences in outcomes between active and placebo TENS suggests that TENS has the potential to decrease pain on movement more than pain on rest. Nine patients did not consider that a placebo was used; the remaining 10 correctly identified placebo TENS. Feasibility studies are important in palliative care prior to undertaking clinical trials. Our findings suggest that further work is required on recruitment strategies and refining the control arm before evaluating TENS in cancer bone pain. Cancer bone pain is common and severe, and partly mediated by hyperexcitability. Animal studies suggest that Transcutaneous Electrical Nerve Stimulation can reduce hyperalgesia. This study examined the feasibility of evaluating TENS in patients with cancer bone pain in order to optimize methods before a phase III trial. Copyright 2010 American Pain Society. Published by Elsevier Inc. All rights reserved.

Safety and feasibility of breast lesion localization using magnetic seeds (Magseed): a multi-centre, open-label cohort study.

PubMed

Harvey, James R; Lim, Yit; Murphy, John; Howe, Miles; Morris, Julie; Goyal, Amit; Maxwell, Anthony J

2018-06-01

Wire localization has several disadvantages, notably wire migration and difficulty scheduling the procedure close to surgery. Radioactive seed localization overcomes these disadvantages, but implementation is limited due to radiation safety requirements. Magnetic seeds potentially offer the logistical benefits and transcutaneous detection equivalence of a radioactive seed, with easier implementation. This study was designed to evaluate the feasibility and safety of using magnetic seeds for breast lesion localization. A two-centre open-label cohort study to assess the feasibility and safety of magnetic seed (Magseed) localization of breast lesions. Magseeds were placed under radiological guidance into women having total mastectomy surgery. The primary outcome measure was seed migration distance. Secondary outcome measures included accuracy of placement, ease of transcutaneous detection, seed integrity and safety. Twenty-nine Magseeds were placed into the breasts of 28 patients under ultrasound guidance. There was no migration of the seeds between placement and surgery. Twenty-seven seeds were placed directly in the target lesion with the other seeds being 2 and 3 mm away. All seeds were detectable transcutaneously in all breast sizes and at all depths. There were no complications or safety issues. Magnetic seeds are a feasible and safe method of breast lesion localization. They can be accurately placed, demonstrate no migration in this feasibility study and are detectable in all sizes and depths of breast tissue. Now that safety and feasibility have been demonstrated, further clinical studies are required to evaluate the seed's effectiveness in wide local excision surgery.

Blue-green diode-pumped solid state laser system for transcutaneous bilirubinometry in neonatal jaundice

NASA Astrophysics Data System (ADS)

Hamza, Mostafa; El-Ahl, Mohammad H. S.; Hamza, Ahmad M.

2001-01-01

The authors introduce the design of a blue-green diode- pumped solid-state laser system for transcutaneous measurement of serum bilirubin level in jaundiced new born infant. The system follows the principles of optical bilirubinometry. The choice of wavelengths provides correction for the presence of hemoglobin. The new design is more compact and less expensive.

Development of ultrasonic methods for hemodynamic measurements

NASA Technical Reports Server (NTRS)

Histand, M. B.; Miller, C. W.; Wells, M. K.; Mcleod, F. D.; Greene, E. R.; Winter, D.

1975-01-01

A transcutanous method to measure instantaneous mean blood flow in peripheral arteries of the human body was defined. Transcutanous and implanted cuff ultrasound velocity measurements were evaluated, and the accuracies of velocity, flow, and diameter measurements were assessed for steady flow. Performance criteria were established for the pulsed Doppler velocity meter (PUDVM), and performance tests were conducted. Several improvements are suggested.

Point Spectroscopy System for Noncontact and Noninvasive Prediction of Transcutaneous Bilirubin Concentration

NASA Astrophysics Data System (ADS)

Ong, P. E.; K. C Huong, Audrey

2017-08-01

This paper presents the use of a point spectroscopy system to determine one’s transcutaneous bilirubin level using Modified Lambert Beer model and the developed fitting routine. This technique required a priori knowledge of extinction coefficient of bilirubin and hemoglobin components in the wavelength range of 440-500 nm for the prediction of the required parameter value. This work was conducted on different skin sites of six healthy Asians namely on the thenar region of the palm of their hand, back of the hand, posterior and anterior forearm. The obtained results revealed the lowest mean transcutaneous bilirubin concentration of 0.44±0.3 g/l predicted for palm site while the highest bilirubin level of 0.98±0.2 g/l was estimated for posterior forearm. These values were also compared with that presented in the literature. This study found considerably good consistency in the value predicted for different subjects especially at the thenar region of the palm. This work concluded that the proposed system and technique may be suitably served as an alternative means to noncontact and noninvasive measurement of one’s transcutaneous bilirubin level at palm site.

Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review

PubMed Central

Bocan, Kara N.; Sejdić, Ervin

2016-01-01

Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver. PMID:26999154

Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review.

PubMed

Bocan, Kara N; Sejdić, Ervin

2016-03-18

Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver.

Synergetic analgesic effect of the combination of arnica and hydroxyethyl salicylate in ethanolic solution following cutaneous application by transcutaneous electrostimulation.

PubMed

Kucera, Miroslav; Horácek, Ondrej; Kálal, Jan; Kolár, Pavel; Korbelar, Peter; Polesná, Zora

2003-01-01

A combination of the active agents arnica and hydroxyethyl salicylate (HES) in ethanolic solution (Sportino Acute Spray) is cutaneously applied for the treatment of sports injuries and diseases of the locomotor apparatus. The aim was to examine the efficacy and synergism of the single substances and the combination with regard to the analgesic effect after cutaneous application as well as to validate the method of transcutaneous electronic stimulation as a method of measuring the analgesic effect. In the present article, the method of transcutaneous electrostimulation was used in a randomized, controlled, single-blind trial on healthy volunteers to provide objective evidence that the combination of active agents displays a significantly greater analgesic effect than the individual active agents. Thus there is synergy between the active agents arnica and hydroxyethyl salicylate in the combination preparation. In addition, the effect of the vehicle ethanol and the reference substance water could be determined within the framework of these comparative experiments and the difference between the combination preparation and the individual substances arnica and HES could be shown. The method of transcutaneous electrostimulation used for the objective measurement of the analgesic effect was validated.

Adjunct High Frequency Transcutaneous Electric Stimulation (TENS) for Postoperative Pain Management during Weaning from Epidural Analgesia Following Colon Surgery: Results from a Controlled Pilot Study.

PubMed

Bjerså, Kristofer; Jildenstaal, Pether; Jakobsson, Jan; Egardt, Madelene; Fagevik Olsén, Monika

2015-12-01

The potential benefit of nonpharmacological adjunctive therapy is not well-studied following major abdominal surgery. The aim of the present study was to investigate transcutaneous electrical nerve stimulation (TENS) as a complementary nonpharmacological analgesia intervention during weaning from epidural analgesia (EDA) after open lower abdominal surgery. Patients were randomized to TENS and sham TENS during weaning from EDA. The effects on pain at rest, following short walk, and after deep breath were assessed by visual analog scale (VAS) grading. Number of patients assessed was lower than calculated because of change in clinical routine. Pain scores overall were low. A trend of lower pain scores was observed in the active TENS group of patients; a statistical significance between the groups was found for the pain lying prone in bed (p < .05). This controlled pilot study indicates benefits of TENS use in postoperative pain management during weaning from EDA after open colon surgery. Further studies are warranted in order to verify the potential beneficial effects from TENS during weaning from EDA after open, lower abdominal surgery. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

The re-design at the transformer portion of transcutaneous energy transmission system for all implantable devices.

PubMed

Watada, Masaya; Saisho, Ryohei; Kim, Yong-Jae; Ohuchi, Katsuhiro; Takatani, Setsuo; Um, Yong-Su

2007-01-01

All implantable devices, such as an artificial heart, an artificial lung, a pacemaker, a defibrillator, need electric power. So the electric power supply through the skin is requested. Then, it is transcutaneous energy transmission system (TETS) that has been studied and used a lot. TETS is the system which performs an electric power supply by non-contact transcutaneously using the electromagnetic induction phenomenon of an external primary side coil and a secondary side coil in human body. In this research, we are developing the core type TETS which applied for the implantable devices. In this paper, corresponding to various conditions, such as a difference in required electric power and transmission distance change, the core type transformer which can hold high transmission efficiency is designed.

Combined effects of cerebellar transcranial direct current stimulation and transcutaneous spinal direct current stimulation on robot-assisted gait training in patients with chronic brain stroke: A pilot, single blind, randomized controlled trial.

PubMed

Picelli, Alessandro; Chemello, Elena; Castellazzi, Paola; Filippetti, Mirko; Brugnera, Annalisa; Gandolfi, Marialuisa; Waldner, Andreas; Saltuari, Leopold; Smania, Nicola

2018-01-01

Preliminary evidence showed additional effects of anodal transcranial direct current stimulation over the damaged cerebral hemisphere combined with cathodal transcutaneous spinal direct current stimulation during robot-assisted gait training in chronic stroke patients. This is consistent with the neural organization of locomotion involving cortical and spinal control. The cerebellum is crucial for locomotor control, in particular for avoidance of obstacles, and adaptation to novel conditions during walking. Despite its key role in gait control, to date the effects of transcranial direct current stimulation of the cerebellum have not been investigated on brain stroke patients treated with robot-assisted gait training. To evaluate the effects of cerebellar transcranial direct current stimulation combined with transcutaneous spinal direct current stimulation on robot-assisted gait training in patients with chronic brain stroke. After balanced randomization, 20 chronic stroke patients received ten, 20-minute robot-assisted gait training sessions (five days a week, for two consecutive weeks) combined with central nervous system stimulation. Group 1 underwent on-line cathodal transcranial direct current stimulation over the contralesional cerebellar hemisphere + cathodal transcutaneous spinal direct current stimulation. Group 2 received on-line anodal transcranial direct current stimulation over the damaged cerebral hemisphere + cathodal transcutaneous spinal direct current stimulation. The primary outcome was the 6-minute walk test performed before, after, and at follow-up at 2 and 4 weeks post-treatment. The significant differences in the 6-minute walk test noted between groups at the first post-treatment evaluation (p = 0.041) were not maintained at either the 2-week (P = 0.650) or the 4-week (P = 0.545) follow-up evaluations. Our preliminary findings support the hypothesis that cathodal transcranial direct current stimulation over the contralesional cerebellar hemisphere in combination with cathodal transcutaneous spinal direct current stimulation might be useful to boost the effects of robot-assisted gait training in chronic brain stroke patients with walking impairment.

Transcutaneous blood glucose monitoring system based on an ISFET glucose sensor and studies on diabetic patients.

PubMed

Ito, N; Saito, A; Kayashima, S; Kimura, J; Kuriyama, T; Nagata, N; Arai, T; Kikuchi, M

1995-01-01

A transcutaneous blood glucose monitoring system consists of an ion-sensitive field-effect transistor (ISFET) glucose sensor unit and a suction effusion fluid (SEF) collecting unit. The SEF is directly collected by a weak suction (400 mmHg absolute pressure) through the skin from which the corneum layer of the epidermis has been previously removed. An ISFET glucose sensor unit is able to measure glucose concentrations in a microliter order sampling volume. The system was applied to three diabetic patients during a 75 g oral glucose tolerance test for monitoring blood glucose levels. During the experiments, glucose changes in the SEF followed actual blood glucose levels with 10 min delays. Results suggest the feasibility of utilizing quasi-continuous, transcutaneous blood glucose monitoring for individual patients with various diabetic histories or diabetic complications.

Transcutaneous electrical neurostimulation in functional pain.

PubMed

Richardson, R R; Arbit, J; Siqueira, E B; Zagar, R

1981-01-01

Transcutaneous electrical neurostimulation (TENS) has recently emerged as a distinct therapeutic modality in the alleviation of acute and chronic pain. We applied this modality to 15 nonsurgical low-back pain patients having diagnoses of functional pain, with 40% initially having significant pain relief (50% of greater). However, this pain-alleviating effect of TENS did not last longer than two months. After initiation of neurostimulation, increased pain and/or bizarre and inappropriate sensations and behavior frequently developed. We also applied this modality in the diagnostic evaluation and treatment of 24 patients having diagnoses of postsurgical chronic intractable low-back pain of psychosomatic origin and achieved similar results. In both groups, we utilized a simplified poststimulation "normal-saline-sterile-water intramuscular injection test" to confirm the findings from transcutaneous electrical neurostimulation and to verify the functional basis of the present low-back pain.

Transcutaneous Electrical Acupoint Stimulation in Children with Autism and Its Impact on Plasma Levels of Arginine-Vasopressin and Oxytocin: A Prospective Single-Blinded Controlled Study

ERIC Educational Resources Information Center

Zhang, Rong; Jia, Mei-Xiang; Zhang, Ji-Sui; Xu, Xin-Jie; Shou, Xiao-Jing; Zhang, Xiu-Ting; Li, Li; Li, Ning; Han, Song-Ping; Han, Ji-Sheng

2012-01-01

Acupuncture increases brain levels of arginine-vasopressin (AVP) and oxytocin (OXT), which are known to be involved in the modulation of mammalian social behavior. Transcutaneous electrical acupoint stimulation (TEAS) is often used clinically to produce a similar stimulation to that of acupuncture on the acupoints. In the present study, TEAS was…

Transcutaneous sacral neurostimulation for irritative voiding dysfunction.

PubMed

Walsh, I K; Johnston, R S; Keane, P F

1999-01-01

Patients with irritative voiding dysfunction are often unresponsive to standard clinical treatment. We evaluated the response of such individuals to transcutaneous electrical stimulation of the third sacral nerve. 32 patients with refractory irritative voiding dysfunction (31 female and 1 male; mean age 47 years) were recruited to the study. Ambulatory transcutaneous electrical neurostimulation was applied bilaterally to the third sacral dermatomes for 1 week. Symptoms of frequency, nocturia, urgency, and bladder pain were scored by each patient throughout and up to 6 months following treatment. The mean daytime frequency was reduced from 11.3 to 7.96 (p = 0.01). Nocturia episodes were reduced from a mean of 2.6 to 1.8 (p = 0.01). Urgency and bladder pain mean symptom scores were reduced from 5.97 to 4.89 and from 1.48 to 0.64, respectively. After stopping therapy, symptoms returned to pretreatment levels within 2 weeks in 40% of the patients and within 6 months in 100%. Three patients who continued with neurostimulation remained satisfied with this treatment modality at 6 months. Transcutaneous third sacral nerve stimulation may be an effective and noninvasive ambulatory technique for the treatment of patients with refractory irritative voiding dysfunction. Following an initial response, patients may successfully apply this treatment themselves to ensure long-term relief.

Analysis of current density and specific absorption rate in biological tissue surrounding an air-core type of transcutaneous transformer for an artificial heart.

PubMed

Shiba, Kenji; Nukaya, Masayuki; Tsuji, Toshio; Koshiji, Kohji

2006-01-01

This paper reports on the specific absorption rate (SAR) and the current density analysis of biological tissue surrounding an air-core type of transcutaneous transformer for an artificial heart. The electromagnetic field in the biological tissue surrounding the transformer was analyzed by the transmission-line modeling method, and the SAR and current density as a function of frequency (200k-1 MHz) for a transcutaneous transmission of 20 W were calculated. The model's biological tissue has three layers including the skin, fat and muscle. As a result, the SAR in the vicinity of the transformer is sufficiently small and the normalized SAR value, which is divided by the ICNIRP's basic restriction, is 7 x 10(-3) or less. On the contrary, the current density is slightly in excess of the ICNIRP's basic restrictions as the frequency falls and the output voltage rises. Normalized current density is from 0.2 to 1.2. In addition, the layer in which the current's density is maximized depends on the frequency, the muscle in the low frequency (<700 kHz) and the skin in the high frequency (>700 kHz). The result shows that precision analysis taking into account the biological properties is very important for developing the transcutaneous transformer for TAH.

The effects of transcutaneous low-level laser therapy on the skin healing process: an experimental model.

PubMed

Ramos, Felipe Scholz; Maifrino, Laura Beatriz Mesiano; Alves, Sarah; da Costa Aguiar Alves, Beatriz; Perez, Matheus Moreira; Feder, David; Azzalis, Ligia Ajaime; Junqueira, Virginia Berlanga Campos; Fonseca, Fernando Luiz Affonso

2018-01-06

We aim to evaluate the action of transcutaneous laser in the initial wound healing process. The use of low-level laser therapy (LLLT) has proven to be effective on inflammatory modulation and wound healing. The trial was performed on five groups of rats, through a dorsal incision. All groups received treatment on auricular artery. Groups 1 and 3 were treated with transcutaneous LLLT over a period of 15 min. Groups 2 and 4 received one and two inactive laser applications (placebo), respectively. Group 5 was the control one. Blood samples were collected 2 h after the last application of LLLT so that cytokine levels could be measured by ELISA. Tissue fragments were harvested for morphometric, histomorphometric, and RT-qPCR analyses. The morphometric analysis revealed a greater decrease in the wounded area in G1 when compared with G2, whereas in G3, the improvement in the area was greater when compared with G4. Finally, the histomorphometric analysis showed that G1 was the group closer to G5 in terms of collagen fiber count. G2 and G4 had higher amounts of collagen fibers than G5 while G3 had a lower quantity. The use of the transcutaneous LLLT in the current study influenced the wound healing process.

Studies on the temperature distribution of a thick film transcutaneous oxygen sensor and its thermal influences on oxygen measurement.

PubMed

Lam, Liza; Bilek, Jaromir; Atkinson, John

2006-11-01

The partial pressures of gases, namely oxygen and carbon dioxide, in the arterial blood are important parameters for doctors to determine the respiratory conditions of patients. Currently in practice, there are a number of ways to measure these parameters, one of which is transcutaneous blood gas monitoring. This technique is a popular noninvasive measurement method for obtaining fast and relatively accurate responses. In this investigation, thick film technology has been employed to develop an amperometric oxygen sensor which consists of a heating module to elevate the temperature at the skin surface to transcutaneous levels. The heating module includes a heating element and its temperature is regulated by a temperature control circuit. Using an infrared camera, the transient and steady-state temperature distributions as well as the stability of the heating element have been analysed. The influence of temperature on the oxygen sensing module is also studied. In addition, a three-dimensional theoretical model is established to evaluate the thermal response of the sensor and subsequently compared with the results from the practical prototype. With this model, the design stages can be simplified and future heating modules for transcutaneous sensors could be generated and improved more easily and effectively.

Near infrared spectroscopy evaluation of bladder function: the impact of skin pigmentation on detection of physiologic change during voiding

NASA Astrophysics Data System (ADS)

Shadgan, Babak; Stothers, Lynn; Molavi, Behnam; Mutabazi, Sharif; Mukisa, Ronald; Macnab, Andrew

2015-02-01

Background: Prior research indicates the epidermal pigment layer of human skin (Melanin) has a significant absorption coefficient in the near infra-red (NIR) region; hence attenuation of light in vivo is a potential confounder for NIR spectroscopy (NIRS). A NIRS method developed for transcutaneous evaluation of bladder function is being investigated as a means of improving the burden of bladder disease in sub-Saharan Africa. This required development of a simple wireless NIRS device suitable for use as a screening tool in patients with pigmented skin where the NIR light emitted would penetrate through the epidermal pigment layer and return in sufficient quantity to provide effective monitoring. Methods: Two healthy subjects, one with pigmented skin and one with fair skin, were monitored as they voided spontaneously using the prototype transcutaneous NIRS device positioned over the bladder. The device was a self-contained wireless unit with light emitting diodes (wavelengths 760 and 850 nanometres) and interoptode distance of 4cm. The raw optical data were transmitted to a laptop where graphs of chromophore change were generated with proprietary software and compared between the subjects and with prior data from asymptomatic subjects. Results: Serial monitoring was successful in both subjects. Voiding volumes varied between 350 and 380 cc. In each subject the patterns of chromophore change, trend and magnitude of change were similar and matched the physiologic increase in total and oxygenated hemoglobin recognized to occur in normal bladder contraction during voiding. Conclusions: Skin pigmentation does not compromise the ability of transcutaneous NIRS to interrogate physiologic change in the bladder during bladder contraction in healthy subjects.

[The combined laser therapy of rheumatoid arthritis].

PubMed

Sidorov, V D; Mamiliaeva, D R; Derevnina, N A; Reformatskaia, S Iu

2000-01-01

Low-intensity infrared laser radiation to the tympanic vessels was studied as one of the hemophysiotherapeutic methods and as a component of combined treatment in which it accompanies local transcutaneous laser radiation of the affected joints. It is shown that immunomodulation is feasible under noninvasive interauricular laser effect on hemostasis. Indications for both laser regimens are formulated. Joint exposure to transcutaneous laser radiation is contraindicated if the affected joints have an exudative component of inflammation.

Modulation of laser-evoked potentials and pain perception by transcutaneous electrical nerve stimulation (TENS): a placebo-controlled study in healthy volunteers.

PubMed

Vassal, François; Créac'h, C; Convers, Ph; Laurent, B; Garcia-Larrea, L; Peyron, R

2013-09-01

To investigate the effects of transcutaneous electrical nerve stimulation (TENS) on brain nociceptive responses (laser-evoked potentials, LEPs) and pain perception. Twenty healthy subjects were included. Nociceptive CO(2)-laser pulses were sequentially delivered to the dorsum of both feet. The amplitude of LEPs and nociceptive thresholds were collected in three consecutive conditions: T1: "sham" TENS (2 Hz/low-intensity) positioned heterotopically, over the left thigh; T2: "active" TENS (120 Hz/low-intensity) applied homotopically, over the left common peroneal nerve; and T3: "sham" TENS (replication of condition T1). Compared with "sham" TENS, "active" TENS significantly decreased the LEPs amplitude. This effect was observed exclusively when "active" TENS was applied ipsilaterally to the painful stimulus. Nociceptive thresholds increased with sessions in both limbs, but the increase observed during the "active" condition of TENS (T2) exceeded significantly that observed during the condition T3 only on the foot ipsilateral to TENS. Compared with a credible placebo TENS, high-frequency TENS induced a significant attenuation of both the acute pain and LEPs induced by noxious stimuli applied on the same dermatome. This modulation of subjective and objective concomitants of pain processing reflects a real neurophysiological TENS-related effect on nociceptive transmission. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Different effects of transcutaneous electric nerve stimulation and electroacupuncture at ST36–ST37 on the cerebral cortex

PubMed Central

Kang, Yu-Tien; Liao, Yi-Sheng; Hsieh, Ching-Liang

2015-01-01

Background The effects of transcutaneous electric nerve stimulation (TENS) and electroacupuncture (EA) on the cerebral cortex are largely unclear. The purpose of the present study was to investigate the effect of TENS and EA on the cerebral cortex by examining their effect on the median nerve-somatosensory evoked potentials (MN-SEPs). Methods Twenty volunteers were studied. The cortical and cervical spinal potentials were recorded by median nerve stimulation at the left wrist. Sham TENS, 2 Hz TENS and 2 Hz EA were applied to both ST36 and ST37. MN-SEPs were recorded during sham TENS, 2 Hz TENS and 2 Hz EA, with at least 1 week interval for each subject. One-way analysis of variance was used to determine the differences in latency and amplitude of the MN-SEPs observed in the stimulation and post-stimulation periods compared with baseline. Scheffe's post hoc correction was employed to identify pairwise differences. Results No differences in mean latency were found between the stimulation procedures during the stimulation and post-stimulation periods. 2 Hz EA but not sham TENS or 2 Hz TENS caused higher mean amplitudes in N20 and N30 during the stimulation and post-stimulation periods. Conclusions EA, but not TENS, induces changes in certain components of the signal. PMID:25432425

A novel transcutaneous, non-focused ultrasound energy delivering device is able to induce subcutaneous adipose tissue destruction in an animal model.

PubMed

Levi, Assi; Amitai, Dan Ben; Lapidoth, Moshe

2017-01-01

The understanding that adipocytes are greatly influenced by thermal changes combined with the advancement of non-invasive ultrasound technologies have led to the application of ultrasound as an energy source to induce thermal fat destruction. While application of high intensity focused, ultrasound energy have been widely explored, there is far less information regarding the effects of non-focused ultrasound on adipose tissue. The purpose of this study was to characterize the effects of a novel transcutaneous, multi-elements, non-focused ultrasound energy regimen in an animal model, as a proof-of-concept of its potential to treat non-invasive subcutaneous benign tumors. The non-invasive transcutaneous ultrasound system prototype (LUMENIS, Ltd., Yoqneam, Israel) was applied to thermally induce adipocytes' death. During treatment, the ultrasound energy was transmitted into the subcutaneous adipose tissue (SAT) of 12 domestic adult female pigs. Two modes of operation (long and short), which differ in both the acoustic energy applied to the tissue and in their time durations (i.e., differ in their power settings), were used in this study. Efficacy and safety assessments included: Temperature measurement of skin and subcutaneous adipose tissue (SAT) visual inspection and ultrasound imaging of the thermally affected areas, histopathological assessment of tissue samples using hematoxylin & eosin, and Masson's trichrome stains and in situ cell death detection kit for apoptosis assessment. The long and short treatment modes led to a 13.2°C and 17.8°C rise from baseline, respectively, in the SAT, whereas skin surface temperature was practically unaffected. Visual, ultrasonographic, and histopathological evaluation of the treated area showed SAT ablation. No treatment-related changes were observed in the epidermis, dermis subcutaneous muscle and nerves, or in livers and kidneys of treated animals. Additionally, no significant changes from baseline in blood- and urine-borne analytes were detected post-treatment. The novel transcutaneous, multi-elements, non-focused ultrasound energy regimen used in this study, proved effective in non-invasively ablating SAT in an animal model. The usage of low energy settings such as in the current study might reduce unwanted side effects related to high energy application. Lasers Surg. Med. 49:110-121, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A graphene-based electrochemical device with thermoresponsive microneedles for diabetes monitoring and therapy

NASA Astrophysics Data System (ADS)

Lee, Hyunjae; Choi, Tae Kyu; Lee, Young Bum; Cho, Hye Rim; Ghaffari, Roozbeh; Wang, Liu; Choi, Hyung Jin; Chung, Taek Dong; Lu, Nanshu; Hyeon, Taeghwan; Choi, Seung Hong; Kim, Dae-Hyeong

2016-06-01

Owing to its high carrier mobility, conductivity, flexibility and optical transparency, graphene is a versatile material in micro- and macroelectronics. However, the low density of electrochemically active defects in graphene synthesized by chemical vapour deposition limits its application in biosensing. Here, we show that graphene doped with gold and combined with a gold mesh has improved electrochemical activity over bare graphene, sufficient to form a wearable patch for sweat-based diabetes monitoring and feedback therapy. The stretchable device features a serpentine bilayer of gold mesh and gold-doped graphene that forms an efficient electrochemical interface for the stable transfer of electrical signals. The patch consists of a heater, temperature, humidity, glucose and pH sensors and polymeric microneedles that can be thermally activated to deliver drugs transcutaneously. We show that the patch can be thermally actuated to deliver Metformin and reduce blood glucose levels in diabetic mice.

Nano-sized Soluplus® polymeric micelles enhance the induction of tetanus toxin neutralising antibody response following transcutaneous immunisation with tetanus toxoid.

PubMed

Saydam, Manolya; Cheng, Woei Ping; Palmer, Nathan; Tierney, Robert; Francis, Robert; MacLellan-Gibson, Kirsty; Khan, Ambreen; Mawas, Fatme

2017-04-25

The use of Soluplus® polymeric micelles as a novel adjuvant for tetanus toxoid (TTxd) in transcutaneous immunisation was evaluated. TTxd was added to Soluplus® polymeric micelles to form TTxd-Soluplus® nano-aggregates with a size of 68nm. Non-adjuvanted TTxd commonly induces very poor antibody response by the transcutaneous route. However, in this study, the use of TTxd-Soluplus® resulted in a significant increase in the antibody response to TTxd, which was similar to that induced in the presence of CPG-oligodeoxynucleotides (CPG-ODNs) adjuvant. The toxin neutralising potency of the immune sera induced by TTxd-Soluplus® was also much stronger than that from TTxd alone, in a passive transfer experiment in mice. Soluplus® also enhanced the immunogenicity of the toxoid when TTxd-Soluplus® was stored at 4°C for 4weeks, but not at higher temperatures. Confocal microscopy imaging showed a much higher uptake of TTxd in the epidermis and dermis layers of the skin when it was associated with Soluplus®, suggesting that the mechanism for Soluplus® adjuvanticity is through enhanced uptake of the TTxd through the skin. Overall, our findings demonstrated that Soluplus® is an effective novel adjuvant for transcutaneous immunisation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of BiliCare™ transcutaneous bilirubin device in Japanese newborns.

PubMed

Yamana, Keiji; Morioka, Ichiro; Kurokawa, Daisuke; Fukushima, Sachiyo; Nishida, Kosuke; Ohyama, Shohei; Nishimura, Noriyuki; Nozu, Kandai; Taniguchi-Ikeda, Mariko; Nagase, Hiroaki; Fujioka, Kazumichi; Iwatani, Sota; Nakamura, Hajime; Iijima, Kazumoto

2017-10-01

Non-invasive transcutaneous bilirubin (TcB) monitoring has been widely used to screen for hyperbilirubinemia. TcB measured using the recently developed BiliCare™ system, however, has not been fully evaluated. One hundred and seven TcB measurements were obtained from 82 Japanese newborns ≥35 weeks' gestational age within 2 weeks after birth. Measurements were taken at the scaphoid fossa, conchal cavity, and lobe of the ear using BiliCare. BiliCare TcB were compared with total serum bilirubin (TB) and TcB obtained using another bilirubinometer (JM-105™). Transcutaneous bilirubin measured at all three sites significantly correlated with TB (r = 0.91, 0.93, and 0.93 at the scaphoid fossa, conchal cavity, and lobe, respectively). The mean differences were 0.1, -0.3, and 3.6 at the scaphoid fossa, conchal cavity, and lobe, respectively. BiliCare TcB at the scaphoid fossa significantly correlated with that using the JM-105 (r = 0.91). The mean difference was 0.0. BiliCare, however, produced a significantly higher and lower TcB than the JM-105 for TB <7 and ≥15 mg/dL, respectively. Transcutaneous bilirubin measurements taken at the scaphoid fossa or conchal cavity using BiliCare were more reliable than those at the earlobe. BiliCare TcB differed from those of the JM-105, for TB <7 or ≥15 mg/dL. © 2017 Japan Pediatric Society.

Transcutaneous bilirubinometry reduces the need for blood sampling in neonates with visible jaundice.

PubMed

Mishra, S; Chawla, D; Agarwal, R; Deorari, A K; Paul, V K; Bhutani, V K

2009-12-01

We determined usefulness of transcutaneous bilirubinometry to decrease the need for blood sampling to assay serum total bilirubin (STB) in the management of jaundiced healthy Indian neonates. Newborns, > or =35 weeks' gestation, with clinical evidence of jaundice were enrolled in an institutional approved randomized clinical trial. The severity of hyperbilirubinaemia was determined by two non-invasive methods: i) protocol-based visual assessment of bilirubin (VaB) and ii) transcutaneous bilirubin (TcB) determination (BiliCheck). By a random allocation, either method was used to decide the need for blood sampling, which was defined to be present if assessed STB by allocated method exceeded 80% of hour-specific threshold values for phototherapy (2004 AAP Guidelines). A total of 617 neonates were randomized to either TcB (n = 314) or VaB (n = 303) groups with comparable gestation, birth weight and postnatal age. Need for blood sampling to assay STB was 34% lower (95% CI: 10% to 51%) in the TcB group compared with VaB group (17.5% vs 26.4% assessments; risk difference: -8.9%, 95% CI: -2.4% to -15.4%; p = 0.008). Routine use of transcutaneous bilirubinometry compared with systematic visual assessment of bilirubin significantly reduced the need for blood sampling to assay STB in jaundiced term and late-preterm neonates. (ClinicalTrials.gov number, NCT00653874).

Investigation of unifying transcutaneous transformer for transmission of energy and information.

PubMed

Tamura, Nozomi; Yamamoto, Takahiko; Aoki, Hirooki; Koshiji, Kohji; Homma, Akihiko; Tatsumi, Eisuke; Taenaka, Yoshiyuki

2009-01-01

When patients are fitted with a totally implantable artificial heart (TAH), they need to be implanted with two additional devices: one for the transmission of energy and one for information. However, this is a cumbersome process that affects the quality of life of the recipient. Therefore, we investigated the use of electromagnetic coupling for the transmission of energy and information and the possibility of unifying two transcutaneous transformers for the simultaneous transmission of energy and information. While unifying the transformers, it is important to suppress the electromagnetic coupling between energy and information transmission. Therefore, we ensured that the electromagnetic fields generated from the transformer windings for the transmissions of information and energy intersected perpendicularly. If the fields are perpendicular, the electromagnetic coupling between the energy and information transmissions will be suppressed significantly. The characteristics of the simultaneous transmission of information and energy using the unified transcutaneous transformer, developed experimentally, were evaluated by changing the number of windings used for the transmission of information. The electromagnetic coupling between the energy and information transmissions was suppressed by determining the direction of the magnetic field. Moreover, the optimum number of transformer windings required for the simultaneous transmission of energy and information was determined. We concluded that the externally coupled transcutaneous transformer unified for the simultaneous transmission of energy and information performed with good transmission characteristics.

Transcutaneous Drainage of Gel-Like Substance after Application of Hydrogel Dural Sealant: Report of Two Cases.

PubMed

Siman, Homayoun; Techy, Fernando

2016-02-01

Study Design Case report. Objective Incidental durotomy (IDT) is a common complication of spinal surgery. The use of collagen matrix graft along with hydrogel dural sealant is a common method of IDT repair. With this method, there have been several reported cases of detrimental dural sealant expansion in the literature. One case study reported an expansion rate greater than 300%; many report neurologic damage. This article reports the clinical course of two patients who developed postoperative transcutaneous drainage of a gel-like substance after the use of a dural sealant, which is a previously unreported complication. Methods The clinical course and treatment outcome of two patients is presented. Results Both patients experienced postoperative transcutaneous drainage of a gel-like substance at the surgical site. Case one began draining this substance on postoperative day 14. This patient required no further intervention, and the drainage ended after 3 mL of a gel-like substance was expressed from his incision while in the clinic. Case two began draining the gel on postoperative day 16. This patient underwent two washout procedures and resolution of the drainage. No infection was ever detected. Conclusions To our knowledge, our patients are the first reported cases of transcutaneous drainage of expanded dural sealant. It is important to take into consideration the unexpected expansion of a dural sealant when using it for the repair of IDT.

Transcutaneous Drainage of Gel-Like Substance after Application of Hydrogel Dural Sealant: Report of Two Cases

PubMed Central

Siman, Homayoun; Techy, Fernando

2015-01-01

Study Design Case report. Objective Incidental durotomy (IDT) is a common complication of spinal surgery. The use of collagen matrix graft along with hydrogel dural sealant is a common method of IDT repair. With this method, there have been several reported cases of detrimental dural sealant expansion in the literature. One case study reported an expansion rate greater than 300%; many report neurologic damage. This article reports the clinical course of two patients who developed postoperative transcutaneous drainage of a gel-like substance after the use of a dural sealant, which is a previously unreported complication. Methods The clinical course and treatment outcome of two patients is presented. Results Both patients experienced postoperative transcutaneous drainage of a gel-like substance at the surgical site. Case one began draining this substance on postoperative day 14. This patient required no further intervention, and the drainage ended after 3 mL of a gel-like substance was expressed from his incision while in the clinic. Case two began draining the gel on postoperative day 16. This patient underwent two washout procedures and resolution of the drainage. No infection was ever detected. Conclusions To our knowledge, our patients are the first reported cases of transcutaneous drainage of expanded dural sealant. It is important to take into consideration the unexpected expansion of a dural sealant when using it for the repair of IDT. PMID:26835216

New-Onset Left Bundle Branch Block Induced by Transcutaneous Aortic Valve Implantation.

PubMed

Massoullié, Grégoire; Bordachar, Pierre; Ellenbogen, Kenneth A; Souteyrand, Géraud; Jean, Frédéric; Combaret, Nicolas; Vorilhon, Charles; Clerfond, Guillaume; Farhat, Mehdi; Ritter, Philippe; Citron, Bernard; Lusson, Jean-R; Motreff, Pascal; Ploux, Sylvain; Eschalier, Romain

2016-03-01

New-onset left bundle branch block (LBBB) is a specific concern of transcutaneous aortic valve implantation (TAVI) given its estimated incidence ranging from 5% to 65%. This high rate of occurrence is dependent on the type of device used (size and shape), implantation methods, and patient co-morbidities. The appearance of an LBBB after TAVI reflects a very proximal lesion of the left bundle branch as it exits the bundle of His. At times transient, its persistence can lead to permanent pacemaker implantation in 15% to 20% of cases, most often for high-degree atrioventricular block. The management of LBBB after TAVI is currently not defined by international societies resulting in individual centers developing their own management strategy. The potential consequences of LBBB are dysrhythmias (atrioventricular block, syncope, and sudden death) and functional (heart failure) complications. Prompt postprocedural recognition and management (permanent pacemaker implantation) of patients prevents the occurrence of potential complications and may constitute the preferred approach in this frail and elderly population despite additional costs and complications of cardiac pacing. Moreover, the expansion of future indications for TAVI necessitates better identification of the predictive factors for the development of LBBB. Indeed, long-term right ventricular pacing may potentially increase the risk of developing heart failure in this population. In conclusion, it is thus imperative to not only develop new aortic prostheses with a less-deleterious impact on the conduction system but also to prescribe appropriate pacing modes in this frail population. Copyright © 2016 Elsevier Inc. All rights reserved.

A Study on Duration of Effect of Transcutaneous Electrical Nerve Stimulation Therapy on Whole Saliva Flow.

PubMed

Bhasin, Neha; Reddy, Sreedevi; Nagarajappa, Anil Kumar; Kakkad, Ankur

2015-06-01

Saliva is a complex fluid, whose important role is to maintain the well being of oral cavity. Salivary gland hypofunction or hyposalivation is the condition of having reduced saliva production which leads to the subjective complaint of oral dryness termed xerostomia.(7) Management of xerostomia includes palliative therapy using topical agents or systemic therapy. Electrostimulation to produce saliva was studied in the past and showed moderate promise but never became part of mainstream therapy. Hence, this study was undertaken to evaluate the effect of transcutaneous electrical nerve stimulation (TENS) on whole salivary flow rate in healthy adults and to evaluate how long this effect of TENS lasts on salivary flow. One hundred healthy adult subjects were divided into five age groups with each group containing 20 subjects equally divided into males and females in each group. Unstimulated saliva was collected using a graduated test tube fitted with funnel and quantity was measured. Transcutaneous electrical nerve stimulation unit was activated and stimulated saliva was collected. Saliva was again collected 30 minutes and 24 hours post stimulation. The mean unstimulated whole saliva flow rate for all subjects (n = 100) was 2.60 ml/5 min. During stimulation, it increased to 3.60 ± 0.39 ml/5 min. There was 38.46% increase in salivary flow. Ninety six out of 100 responded positively to TENS therapy. Salivary flow remained increased 30 minutes and 24 hours post stimulation with the values being 3.23 ± 0.41 ml/5 min and 2.69 ± 0.39 ml/5 min respectively. Repeated measures One way analysis of variance (ANOVA) test showed that the difference between these values were statistically significant. Transcutaneous electrical nerve stimulation therapy was effective for stimulation of whole saliva in normal, healthy subjects and its effect retained till 30 minutes and a little up to 24 hours. Transcutaneous electrical nerve stimulation may work best synergistically with other sialagogues and can be used for the management of xerostomia.

WITHDRAWN: Transcutaneous electrical nerve stimulation and acupuncture-like transcutaneous electrical nerve stimulation for chronic low back pain.

PubMed

Gadsby, J G; Flowerdew, M W

2007-07-18

In view of the claims and counter-claims of the effectiveness of transcutaneous electrical nerve stimulation, it would seem appropriate to systematically review the literature. To determine the effectiveness of transcutaneous electrical nerve stimulation in reducing pain and improving range of movement in patients with chronic low back pain. Electronic searches of EMBASE, MEDLINE, CISCOM, AMED for all studies of TENS in the English language, identifying those treating chronic low back pain and hand searching their references. The inclusion criterion for studies included in this review, 6 of 68 identified, was comparisons of TENS/ALTENS versus placebo in patients with chronic low back pain. Outcome data on pain reduction, range of movement, functional status and work was extracted by two independent reviewers together with trial design qualities to construct a Quality Index. The ratio of odds of improvement in pain for each comparison was calculated: TENS vs. placebo at 1.62 (95% CI 0.90, 2.68); ALTENS vs. placebo at 7.22 (95% CI 2.60, 20.01) and TENS/ALTENS vs. placebo at 2.11 (95% CI 1.32, 3.38) times that of placebo. An improvement in pain reduction was seen in 45.80% (CI 37.00%, 55.00%) of TENS; 86.70% (CI 80.00%, 93.00%) of ALTENS; 54.00% (CI 46.20%, 61.80%) of TENS/ ALTENS and 36.40% (95%CI 28.40%, 44.40%) of placebo subjects. The odds of improvement in range of movement on ALTENS vs. placebo was 6.61 times (95% CI 2.36, 18.55) that of placebo. Transcutaneous electrical nerve stimulation appears to reduce pain and improve the range of movement in chronic low back pain subjects. A definitive randomised controlled study of ALTENS, TENS, placebo/no treatment controls, of sufficient power, is needed to confirm these findings.

Non-anesthesiologist-administered Propofol is not Related to an Increase in Transcutaneous CO2 Pressure During Flexible Bronchoscopy Compared to Guideline-based Sedation: A Randomized Controlled Trial.

PubMed

Mercado-Longoría, Roberto; Armeaga-Azoños, Carolina; Tapia-Orozco, Jasel; González-Aguirre, Julio E

2017-09-01

Evidence for the use of non-anesthesiologist-administered propofol for sedation during flexible bronchoscopy is scarce. The main objective of this study was to determine whether non-anesthesiologist-administered propofol balanced sedation was related to higher transcutaneous CO 2 pressure compared with current guideline-based sedation (combination midazolam and opioid). Secondary outcomes were post-procedural recuperation time, patient satisfaction and frequency of adverse events. In this randomized controlled trial we included data from outpatients aged 18 years or older with an indication for flexible bronchoscopy in a university hospital in northern Mexico. Ninety-one patients were included: 42 in the midazolam group and 49 in the propofol group. During 60min of transcutaneous capnometry monitoring, mean transcutaneous CO 2 pressure values did not differ significantly between groups (43.6 [7.5] vs. 45.6 [9.6]mmHg, P=.281). Propofol was related with a high Aldrete score at 5, 10, and 15min after flexible bronchoscopy (9 [IQR 6-10] vs. 10 [9,10], P=.006; 9 [8-10] vs. 10 [IQR 10-10], P<.001 and 10 [IQR 9-10] vs. 10 [10], respectively) and with high patient satisfaction on a visual analogue scale of 1 (not satisfied) to 10 (very satisfied) (8.41 [1.25] vs. 8.97 [0.98], P=.03). Frequency of adverse events was similar among groups (30.9% vs. 22.4%, P=.47). Compared with guideline-recommended sedation, non-anesthesiologist-administered propofol balanced sedation is not associated with higher transcutaneous CO 2 pressure or with more frequent adverse effects. Propofol use is associated with faster sedation recovery and with high patient satisfaction. NCT02820051. Copyright © 2017 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

Two-way communication for programming and measurement in a miniature implantable stimulator.

PubMed

Thil, M A; Gérard, B; Jarvis, J C; Delbeke, J

2005-07-01

Implantable stimulators are needed for chronic electrical stimulation of nerves and muscles in experimental studies. The device described exploits the versatility of current microcontrollers for stimulation and communication in a miniature implant. Their standard outputs can provide the required selectable constant-current sources. In this device, pre-programmed stimulation paradigms were selected by transcutaneous light pulses. The potential of a programmable integrated circuit (PIC) was thus exploited. Implantable devices must be biocompatible. A novel encapsulation method that require no specialised equipment and that used two classical encapsulants, silicone and Teflon was developed. It was tested for implantation periods of up to four weeks. A novel way to estimate electrode impedance in awake animals is also presented. It was thus possible to follow the evolution of the nerve-electrode interface and, if necessary, to adjust the stimulation parameters. In practice, the electrode voltage at the end of a known constant-current pulse was measured by the PIC. The binary coded value was then indicated to the user as a series of muscle twitches that represented the binary value of the impedance measurement. This neurostimulator has been successfully tested in vitro and in vivo. Thresholds and impedance values were chronically monitored following implantation of a self-sizing spiral cuff electrode. Impedance variations in the first weeks could reflect morphological changes usually observed after the implantation of such electrodes.

A Pilot Study: Evaluation of the Effects of Treatment with 0.75% Topical Capsaicin in Patients with Reflex Sympathetic Dystrophy Using Three Phase Bone Scintigraphy

DTIC Science & Technology

1991-01-28

were maintained at pre-treatment levels in all patients. Non- pharmaceutical pain therapies such as transcutaneous nerve stimulation , contrast baths and...utilizing passive range of motion, physical and occupational therapy, and counter- irritation, by such means as contrast baths and transcutaneous nerve ...her pain lessened. At ten weeks of treatment she rated pain relief (VAS) to be 82%. H.W. (thalamic pain) rated pain relief at approximately 18%; his

Pulmonoscopy of Snakes.

PubMed

Knotek, Zdenek; Jekl, Vladimir

2015-09-01

Pulmonoscopy is a practical diagnostic tool for investigating respiratory diseases in snakes. Two different approaches exist for pulmonoscopy, tracheal and transcutaneous. The access to the proximal or distal lung is limited by the length and diameter of the endoscope when using the tracheal approach. The transcutaneous approach allows direct evaluation of the lung and distal trachea through the air sac. Both of the methods are safe, and specific contraindications for pulmonoscopy in snakes are not known except for any anesthesia contraindication. Copyright © 2015 Elsevier Inc. All rights reserved.

Influence of transcutaneous electrical nerve stimulation conditions on disynaptic reciprocal Ia inhibition and presynaptic inhibition in healthy adults.

PubMed

Takeda, Kazuya; Tanabe, Shigeo; Koyama, Soichiro; Ushiroyama, Kosuke; Naoi, Yuki; Motoya, Ikuo; Sakurai, Hiroaki; Kanada, Yoshikiyo

2017-03-01

This study investigated the influence of stimulus conditions of transcutaneous electrical nerve stimulation (TENS) on disynaptic reciprocal Ia inhibition (RI) and presynaptic inhibition (D1 inhibition) in healthy adults. Eight healthy participants received TENS (stimulus frequencies of 50, 100, and 200 Hz) over the deep peroneal nerve and tibialis anterior (TA) muscle in the resting condition for 30 min. At pre- and post-intervention, the RI from the TA to the soleus (SOL) and D1 inhibition of the SOL alpha motor neuron were assessed by evoked electromyography. The results showed that RI was not changed by TENS at any stimulus frequency condition. Conversely, D1 inhibition was significantly changed by TENS regardless of the stimulus frequency. The present results and previous studies pertaining to RI suggest that the resting condition might strongly influence the lack of pre- vs. post-intervention change in the RI. Regarding the D1 inhibition, the present results suggest that the effect of TENS might be caused by post-tetanic potentiation. The knowledge gained from the present study might contribute to a better understanding of fundamental studies of TENS in healthy adults and its clinical application for stroke survivors.

Can we "predict" long-term outcome for ambulatory transcutaneous electrical nerve stimulation in patients with chronic pain?

PubMed

Köke, Albère J; Smeets, Rob J E M; Perez, Roberto S; Kessels, Alphons; Winkens, Bjorn; van Kleef, Maarten; Patijn, Jacob

2015-03-01

Evidence for effectiveness of transcutaneous electrical nerve stimulation (TENS) is still inconclusive. As heterogeneity of chronic pain patients might be an important factor for this lack of efficacy, identifying factors for a successful long-term outcome is of great importance. A prospective study was performed to identify variables with potential predictive value for 2 outcome measures on long term (6 months); (1) continuation of TENS, and (2) a minimally clinical important pain reduction of ≥ 33%. At baseline, a set of risk factors including pain-related variables, psychological factors, and disability was measured. In a multiple logistic regression analysis, higher patient's expectations, neuropathic pain, no severe pain (< 80 mm visual analogue scale [VAS]) were independently related to long-term continuation of TENS. For the outcome "minimally clinical important pain reduction," the multiple logistic regression analysis indicated that no multisited pain (> 2 pain locations) and intermittent pain were positively and independently associated with a minimally clinical important pain reduction of ≥ 33%. The results showed that factors associated with a successful outcome in the long term are dependent on definition of successful outcome. © 2014 World Institute of Pain.

Transcutaneous pleural biopsy with a retrograde forceps: a novel approach.

PubMed

Wiewiorski, Martin; Hiebinger, Andreas; Hoechel, Sebastian; Müller-Gerbl, Magdalena; Barg, Alexej; Valderrabano, Victor; Hügle, Thomas

2016-01-01

Pleural biopsies are commonly performed to investigate the cause of exudative pleural effusion. Biopsy needles (e.g. Abrams needle, Cope needle) are traditionally used to perform the biopsy. However, certain complications such as pneumothorax and haemothorax have been described. We present a technique utilizing a novel retrograde forceps, which could improve the simplicity and lower the complication rate of performing closed pleural biopsies. A retrograde forceps (Retroforceps, Karl Storz, Tuttlingen, Germany) was used to perform 20 transcutaneous pleural biopsies in a cadaver thorax under thoracoscopical control. Video documentation of the procedure from outside and inside the thorax was performed. The surgeon performing the biopsy was blinded to the thoracoscopical view. After the removal of the forceps, it was checked whether biopsy material was retrieved. The video material was retrospectively used to confirm whether the biopsy was taken from the pleura parietalis. Biopsy material was retrieved in 19 out of 20 biopsy attempts. Video material confirmed that the biopsy was taken from the pleura parietalis in all cases. Using a retrograde biopsy forceps is a simple and practicable procedure suitable for clinical application. This technique could potentially reduce the incidence of pneumothorax.

Weight Bearing Over-ground Stepping in an Exoskeleton with Non-invasive Spinal Cord Neuromodulation after Motor Complete Paraplegia.

PubMed

Gad, Parag; Gerasimenko, Yury; Zdunowski, Sharon; Turner, Amanda; Sayenko, Dimitry; Lu, Daniel C; Edgerton, V Reggie

2017-01-01

We asked whether coordinated voluntary movement of the lower limbs could be regained in an individual having been completely paralyzed (>4 year) and completely absent of vision (>15 year) using two novel strategies-transcutaneous electrical spinal cord stimulation at selected sites over the spine as well as pharmacological neuromodulation by buspirone. We also asked whether these neuromodulatory strategies could facilitate stepping assisted by an exoskeleton (EKSO, EKSO Bionics, CA) that is designed so that the subject can voluntarily complement the work being performed by the exoskeleton. We found that spinal cord stimulation and drug enhanced the level of effort that the subject could generate while stepping in the exoskeleton. In addition, stimulation improved the coordination patterns of the lower limb muscles resulting in a more continuous, smooth stepping motion in the exoskeleton along with changes in autonomic functions including cardiovascular and thermoregulation. Based on these data from this case study it appears that there is considerable potential for positive synergistic effects after complete paralysis by combining the over-ground step training in an exoskeleton, combined with transcutaneous electrical spinal cord stimulation either without or with pharmacological modulation.

The Effect of Electrical Stimulation in Improving Muscle Tone (Clinical)

NASA Astrophysics Data System (ADS)

Azman, M. F.; Azman, A. W.

2017-11-01

Electrical stimulation (ES) and also known as neuromuscular electrical stimulation (NMES) and transcutaneous electrical stimulation (TES) involves the use of electrical current to stimulate the nerves or nerve endings that innervate muscle beneath the skin. Electrical stimulation may be applied superficially on the skin (transcutaneously) or directly into a muscle or muscles (intramuscularly) for the primary purpose of enhancing muscle function. The basic theoretical premise is that if the peripheral nerve can be stimulated, the resulting excitation impulse will be transmitted along the nerve to the motor endplates in the muscle, producing a muscle contraction. In this work, the effect of mere electrical stimulation to the muscle bulk and strength are tested. This paper explains how electrical stimulation can affect the muscle bulk, muscle size, muscle tone, muscle atrophy and muscle strength. The experiment and data collection are performed on 5 subjects and the results obtained are analyzed. This research aims to understand the full potential of electrical stimulation and identifying its possible benefits or disadvantages to the muscle properties. The results indicated that electrical stimulation alone able to improve muscle properties but with certain limits and precautions which might be useful in rehabilitation programme.

Laser Transcutaneous Bilirubin Meter: A New Device For Bilirubin Monitoring In Neonatal Jaundice

NASA Astrophysics Data System (ADS)

Hamza, Mostafa; Hamza, Mohammad

1988-06-01

Neonates with jaundice require monitoring of serum bilirubin which should be repeated at frequent intervals. However, taking blood samples from neonates is not always an easy job, plus being an invasive and traumatising procedure with the additional risk of blood loss. In this paper the authors present the theory and design of a new noninvasive device for transcutaneous bilirubinometry, using a differential absorption laser system. The new technique depends upon illuminating the skin of the neonate with radiation from a two wave-length oscillation laser. The choice of the wavelengths follows the principles of optical bilirubinometry. For obtaining more accurate measurements, different pairs of two wave-lengths are incorporated in the design. The presence of hemoglobin is corrected for by appropriate selection of the laser wavelengths. The new design was tested for accuracy and precision using an argon ion laser. Correlation study between serum bilirubin determination by laser transcutaneous bilirubinometry and by American optical bilirubinometer was highly significant.

Transcutaneous immunization with tetanus toxoid and mutants of Escherichia coli heat-labile enterotoxin as adjuvants elicits strong protective antibody responses.

PubMed

Tierney, Rob; Beignon, Anne-Sophie; Rappuoli, Rino; Muller, Sylviane; Sesardic, Dorothea; Partidos, Charalambos D

2003-09-01

In this study, the adjuvanticity of 2 nontoxic derivatives (LTK63 and LTR72) of heat-labile enterotoxin of Escherichia coli (LT) was evaluated and was compared with that of a cytosine phosphodiester-guanine (CpG) motif, after transcutaneous immunization with tetanus toxoid (TT). TT plus LTR72 elicited the strongest antibody responses, compared with those elicited by the other vaccines (TT, TT plus LTK63, TT plus CpG, and TT plus LTK63 plus CpG); it neutralized the toxin and conferred full protection after passive transfer in mice. Preexisting immunity to LT mutants did not adversely affect their adjuvant potency. Both LTK63 and LTR72 promoted the induction of IgG1 antibodies. In contrast, mice receiving either CpG motif alone or CpG motif plus LTK63 produced strong IgG2a anti-TT antibody responses. Overall, these findings demonstrate that mutants of enterotoxins with reduced toxicity are effective adjuvants for transcutaneous immunization.

Assessment of transcutaneous vaccine delivery by optical coherence tomography Assessment of transcutaneous vaccine delivery by OCT

NASA Astrophysics Data System (ADS)

Kamali, T.; Doronin, A.; Rattanapak, T.; Hook, S.; Meglinski, I.

2012-08-01

Immunization is one of the most efficient and cost-effective means for the prevention of diseases. The latest trend for inducing protective immunity is topical application of vaccines to intact skin rather than invasive administration via injection. Apart from being a non-invasive route of drug delivery, skin itself also offers advantages through the presence of cells of the immune system in both the dermis and epidermis. However, vaccine penetration through the outermost layers of skin is limited by the barrier provided by the Stratum corneum. In the current study utilizing conventional Optical Coherence Tomography (OCT) we investigate the transcutaneous delivery of a nano- particulate peptide vaccine into mouse skin in vivo. We demonstrate that a front of molecular diffusion within the skin can be clearly observed by using cross-correlations of successive 2D OCT images. Thus, OCT provides a unique tool for quantitative assessment of dynamics of diffusion of drugs, target compounds, analytes, cosmetics and various chemical agents in biological tissues in vivo.

Fractional laser microablation of skin: increasing the efficiency of transcutaneous delivery of particles

NASA Astrophysics Data System (ADS)

Genina, E. A.; Dolotov, L. E.; Bashkatov, A. N.; Tuchin, V. V.

2016-06-01

We study several regimes of fractional laser microablation using a pulsed Er : YAG laser for producing microchannels of different depth and incisions that allow transcutaneous delivery of particles of different size, namely, Al2O3 (27 μm), ZrO2 (smaller than 5 μm) and TiO2 (smaller than 100 nm). The shock wave regime was used both for enhancing the penetration of particles into the ablation zones and as an independent method of particle delivery into the skin. Based on optical coherence tomography we assessed the coherent depth of particle detection in the skin in 2 hours, 3 days and 10 days after the administration. The maximal localisation depth (up to 450 μm) was obtained for TiO2 nanoparticles in the regime of incisions with enhancement of particle penetration by pulses of a multiple-beam hydrodynamic shock wave. The results of the study can be useful for developing new methods of transcutaneous delivery of micro- and nanocarriers of medicinal preparations.

Transcutaneous measurement of hyperbilirubinaemia: comparison of the Minolta jaundice meter and the Ingram icterometer.

PubMed

Bilgen, H; Ince, Z; Ozek, E; Bekiroglu, N; Ors, R

1998-12-01

The effectiveness of two different non-invasive transcutaneous bilirubin measurement devices was compared with serum bilirubin levels in 96 healthy newborns. Transcutaneous measurements were obtained with the Minolta Air Shields jaundice meter and the Ingram icterometer and serum bilirubin levels were determined by a direct spectrophotometric method (Bilitron 444). A linear correlation existed between serum bilirubin values and the readings on both the Minolta jaundice meter (r = 0.83) and the Ingram icterometer (r = 0.78). The Kappa coefficient was 0.66. the sensitivity, specificity and positive and negative predictive values were 100%, 56%, 33% and 100% for the Minolta jaundice meter and 100%, 48%, 29% and 100% for the Ingram icterometer, respectively. The high sensitivity and negative predictive value of both devices render them suitable for screening neonatal hyperbilirubinaemia. However, because of its low cost, the Ingram icterometer is preferable to the more complex and expensive Minolta jaundice meter, especially in countries with a high birth rate, such as Turkey.

Frequency Splitting Analysis and Compensation Method for Inductive Wireless Powering of Implantable Biosensors.

PubMed

Schormans, Matthew; Valente, Virgilio; Demosthenous, Andreas

2016-08-04

Inductive powering for implanted medical devices, such as implantable biosensors, is a safe and effective technique that allows power to be delivered to implants wirelessly, avoiding the use of transcutaneous wires or implanted batteries. Wireless powering is very sensitive to a number of link parameters, including coil distance, alignment, shape, and load conditions. The optimum drive frequency of an inductive link varies depending on the coil spacing and load. This paper presents an optimum frequency tracking (OFT) method, in which an inductive power link is driven at a frequency that is maintained at an optimum value to ensure that the link is working at resonance, and the output voltage is maximised. The method is shown to provide significant improvements in maintained secondary voltage and system efficiency for a range of loads when the link is overcoupled. The OFT method does not require the use of variable capacitors or inductors. When tested at frequencies around a nominal frequency of 5 MHz, the OFT method provides up to a twofold efficiency improvement compared to a fixed frequency drive. The system can be readily interfaced with passive implants or implantable biosensors, and lends itself to interfacing with designs such as distributed implanted sensor networks, where each implant is operating at a different frequency.

Literature Review and Meta-Analysis of Transcutaneous Electrical Nerve Stimulation in Treating Chronic Back Pain

PubMed Central

Wu, Lien-Chen; Weng, Pei-Wei; Chen, Chia-Hsien; Huang, Yi-You; Tsuang, Yang-Hwei; Chiang, Chang-Jung

2018-01-01

Background and Objectives This study is a meta-analysis of randomized controlled trials comparing the efficacy of transcutaneous electrical nerve stimulation (TENS) to a control and to other nerve stimulation therapies (NSTs) for the treatment of chronic back pain. Methods Citations were identified in MEDLINE, the Cochrane Library, Google Scholar, and ClinicalTrials.gov through June 2014 using the following keywords: nerve stimulation therapy, transcutaneous electrical nerve stimulation, back pain, chronic pain. Control treatments included sham, placebo, or medication only. Other NSTs included electroacupuncture, percutaneous electrical nerve stimulation, and percutaneous neuromodulation therapy. Results Twelve randomized controlled trials including 700 patients were included in the analysis. The efficacy of TENS was similar to that of control treatment for providing pain relief (standardized difference in means [SDM] = −0.20; 95% confidence interval [CI], −0.58 to 0.18; P = 0.293). Other types of NSTs were more effective than TENS in providing pain relief (SDM = 0.86; 95% CI, 0.15–1.57; P = 0.017). Transcutaneous electrical nerve stimulation was more effective than control treatment in improving functional disability only in patients with follow-up of less than 6 weeks (SDM = −1.24; 95% CI, −1.83 to −0.65; P < 0.001). There was no difference in functional disability outcomes between TENS and other NSTs. Conclusions These results suggest that TENS does not improve symptoms of lower back pain, but may offer short-term improvement of functional disability. PMID:29394211

Development and clinical trial results of a prototype device for trans-cutaneous monitoring of kidney function

NASA Astrophysics Data System (ADS)

Debreczeny, Martin P.; Dorshow, Richard B.

2017-02-01

A prototype medical device for trans-cutaneous monitoring of kidney function has been developed, validated, and used in a clinical trial on 16 healthy subjects having a wide range of skin color types. The fluorescent tracer agent MB-102 was administered intravenously as a bolus that was varied between 0.5 and 4 μmole/kg subject weight. The tracer agent was tracked as a function of time in plasma by blood sampling and trans-cutaneously at four body sites (sternum, forehead, arm, and side) simultaneously. Excitation was performed with a very low level of amplitude-modulated LED light at 450 nm (<50 μW/cm2), and fluorescence emission was synchronously detected at 570 nm. With adjustment of detection gain between subjects, no skin color dependence was observed of the signal-to-noise ratio (SNR) of the transcutaneous measurements. The primary source of measurement noise appeared to be subject motion, likely due to variations in blood content at the skin measurement site. A typical two-compartment pharmacokinetic dependence was observed with equilibration of the fluorescent agent between the vascular space into which it was injected and the extracellular space into which it subsequently diffused. Variation of this equilibration time was observed across body sites, with the sternum providing the shortest and most consistent equilibration. After equilibration, the terminal fluorescence time dependence at the sternum site was found to be highly correlated with tracer agent concentration time dependence sampled from the blood plasma.

[Physiotherapy and neurogenic lower urinary tract dysfunction in multiple sclerosis patients: a randomized controlled trial].

PubMed

Gaspard, L; Tombal, B; Opsomer, R-J; Castille, Y; Van Pesch, V; Detrembleur, C

2014-09-01

This randomized controlled trial compare the efficacy of pelvic floor muscle training vs. transcutaneous posterior tibial nerve stimulation. Inclusion criteria were EDSS score<7 and presence of lower urinary tract symptoms. Exclusion criteria were multiple sclerosis relapse during the study, active urinary tract infection and pregnancy. The primary outcome was quality of life (SF-Qualiveen questionnaire). Secondary outcomes included overactive bladder (USP questionnaire) score and frequency of urgency episodes (3-day bladder diary). Sample size was calculated after 18 patients were included. Data analysis was blinded. Each patient received 9 sessions of 30 minutes weekly. Patients were randomized in pelvic floor muscles exercises with biofeedback group (muscle endurance and relaxation) or transcutaneous posterior tibial nerve stimulation group (rectangular alternative biphasic current with low frequency). A total of 31 patients were included. No difference appeared between groups for quality of life, overactive bladder and frequency of urgency episodes (respectively P=0.197, P=0.532 et P=0.788). These parameters were significantly improved in pelvic floor muscle training group (n=16) (respectively P=0.004, P=0.002 et P=0.006) and in transcutaneous posterior tibial nerve stimulation group (n=15) (respectively P=0.001, P=0.001 et P=0.031). Pelvic floor muscle training and transcutaneous posterior tibial nerve stimulation improved in the same way symptoms related to urgency in MS patients with mild disability. 2. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Amplification of transcutaneous and percutaneous bone-conduction devices with a test-band in an induced model of conductive hearing loss.

PubMed

Park, Marn Joon; Lee, Jae Ryung; Yang, Chan Joo; Yoo, Myung Hoon; Jin, In Suk; Choi, Chi Ho; Park, Hong Ju

2016-11-01

Transcutaneous devices have a disadvantage, the dampening effect by soft tissue between the bone and devices. We investigated hearing outcomes with percutaneous and transcutaneous devices using test-bands in an induced unilateral conductive hearing loss. Comparison of hearing outcomes of two devices in the same individuals. The right ear was plugged in 30 subjects and a test-band with devices (Cochlear™ Baha® BP110 Power and Sophono® Alpha-2 MPO™) was applied on the right mastoid tip with the left ear masked. Sound-field thresholds, speech recognition thresholds (SRTs), and word recognition scores (WRSs) were compared. Aided thresholds of Sophono were significantly better than those of Baha at most frequencies. Sophono WRSs (86 ± 12%) at 40 dB SPL and SRTs (14 ± 5 dB HL) were significantly better than those (73 ± 24% and 23 ± 8 dB HL) of Baha. However, Sophono WRSs (98 ± 3%) at 60 dB SPL did not differ from Baha WRSs (95 ± 12%). Amplifications of the current transcutaneous device were not inferior to those of percutaneous devices with a test-band in subjects with normal bone-conduction thresholds. Since the percutaneous devices can increase the gain when fixed to the skull by eliminating the dampening effect, both devices are expected to provide sufficient hearing amplification.

Evaluation of transcutaneous electrical simulation to improve recovery from corneal hypoesthesia after LASIK.

PubMed

Ghaffariyeh, Alireza; Peyman, Alireza; Puyan, Sadollah; Honarpisheh, Nazafarin; Bagheri, Babak; Peyman, Mohammadreza

2009-08-01

To evaluate the efficacy, and safety of transcutaneous electrical stimulation (TES) to accelerate corneal nerve regeneration and improved recovery from corneal hypesthasia after laser-assisted in situ keratomileusis (LASIK). Khodadoust Eye Hospital, Shiraz, Fars, Iran This prospective, randomized, clinical study comprised 40 eyes of 20 patients scheduled to undergo bilateral LASIK. In each patient, one eye was randomly assigned to receive transcutaneous electrical stimulation (20 HZ) for 60 minutes, and the other eye allocated as control. Corneal sensitivity was measured using the Cochet-Bonnet esthesiometer in four areas outside and five areas inside the LASIK flap preoperatively, and at 1 day, 1 week, 1 month, and 3 months postoperatively. Best-corrected visual acuity and the incidence of adverse events were noted at each visit. For all four points outside the LASIK flap, normal corneal sensitivity was maintained throughout the study; no significant difference was found between the study eyes and the control eyes at these points (P > 0.05). All points within the LASIK flap except the point closest to the hinge demonstrated profound corneal hypoesthesia at 1 day, 1 week, and 1 month postoperatively, with no differences noted between the control and study eyes (P > 0.05). After 3 months, points within the flap had statistically significantly better corneal sensitivity in the study group than in the control group (P < 0.05). Transcutaneous electrical stimulation significantly improves corneal sensitivity at 3 months after LASIK. This may be due to accelerated corneal nerve regeneration by electrical stimulation.

Different effects of transcutaneous electric nerve stimulation and electroacupuncture at ST36-ST37 on the cerebral cortex.

PubMed

Kang, Yu-Tien; Liao, Yi-Sheng; Hsieh, Ching-Liang

2015-02-01

The effects of transcutaneous electric nerve stimulation (TENS) and electroacupuncture (EA) on the cerebral cortex are largely unclear. The purpose of the present study was to investigate the effect of TENS and EA on the cerebral cortex by examining their effect on the median nerve-somatosensory evoked potentials (MN-SEPs). Twenty volunteers were studied. The cortical and cervical spinal potentials were recorded by median nerve stimulation at the left wrist. Sham TENS, 2 Hz TENS and 2 Hz EA were applied to both ST36 and ST37. MN-SEPs were recorded during sham TENS, 2 Hz TENS and 2 Hz EA, with at least 1 week interval for each subject. One-way analysis of variance was used to determine the differences in latency and amplitude of the MN-SEPs observed in the stimulation and post-stimulation periods compared with baseline. Scheffe's post hoc correction was employed to identify pairwise differences. No differences in mean latency were found between the stimulation procedures during the stimulation and post-stimulation periods. 2 Hz EA but not sham TENS or 2 Hz TENS caused higher mean amplitudes in N20 and N30 during the stimulation and post-stimulation periods. EA, but not TENS, induces changes in certain components of the signal. 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.

Development of mobile phone based transcutaneous billirubinometry

NASA Astrophysics Data System (ADS)

Dumont, Alexander P.; Harrison, Brandon; McCormick, Zachary T.; Ganesh Kumar, Nishant; Patil, Chetan A.

2017-03-01

Infants in the US are routinely screened for risk of neurodevelopmental impairment due to neonatal jaundice using transcutaneous bilirubinometry (TcB). In low-resource settings, such as sub-Saharan Africa, TcB devices are not common, however, mobile camera-phones are now widespread. We provide an update on the development of TcB using the built-in camera and flash of a mobile phone, along with a snap-on adapter containing optical filters. We will present Monte Carlo Extreme modeling of diffuse reflectance in neonatal skin, implications in design, and refined analysis methods.

A distinct biomarker of continuous transcutaneous vagus nerve stimulation treatment in major depressive disorder.

PubMed

Tu, Yiheng; Fang, Jiliang; Cao, Jin; Wang, Zengjian; Park, Joel; Jorgenson, Kristen; Lang, Courtney; Liu, Jun; Zhang, Guolei; Zhao, Yanping; Zhu, Bing; Rong, Peijing; Kong, Jian

Major depression is the fourth leading cause of disability worldwide and poses a socioeconomic burden worldwide. Transcutaneous vagus nerve stimulation (tVNS) is a promising noninvasive clinical device that may reduce the severity of major depression. However, the neural mechanism underlying continuous tVNS has not yet been elucidated. We aimed to explore the effect of hypothalamic subregion functional connectivity (FC) changes during continuous tVNS treatment on major depressive disorder (MDD) patients and to identify the potential biomarkers for treatment outcomes. Forty-one mild to moderate MDD patients were recruited and received either real or sham tVNS treatment for 4 weeks. We used a seed-to-whole brain approach to estimate the FC changes of hypothalamic subregions and their surrounding control areas during continuous tVNS treatment and explored their association with clinical outcome changes after 4 weeks of treatment. Of the thirty-six patients that completed the study, those in the tVNS group had significantly lower scores on the 24-item Hamilton Depression (HAM-D) Rating Scale compared to the sham tVNS group after 4 weeks of treatment. The FC between the bilateral medial hypothalamus (MH) and rostral anterior cingulate cortex (rACC) was significantly decreased during tVNS but not during sham tVNS. The strength of this FC was significantly correlated with HAM-D improvements after 4 weeks of tVNS. The FC between the bilateral MH and rACC may serve as a potential biomarker for the tVNS state and predict treatment responses. Our results provide insights into the neural modulation mechanisms of continuous tVNS and reveal a potential therapeutic target for MDD patients. Copyright © 2018 Elsevier Inc. All rights reserved.

Transcutaneous Electrical Nerve Stimulation Effects on Neglect: A Visual-Evoked Potential Study

PubMed Central

Pitzalis, Sabrina; Spinelli, Donatella; Vallar, Giuseppe; Di Russo, Francesco

2013-01-01

We studied the effects of transcutaneous electrical nerve stimulation (TENS) in six right-brain-damaged patients with left unilateral spatial neglect (USN), using both standard clinical tests (reading, line, and letter cancelation, and line bisection), and electrophysiological measures (steady-state visual-evoked potentials, SSVEP). TENS was applied on left neck muscles for 15′, and measures were recorded before, immediately after, and 60′ after stimulation. Behavioral results showed that the stimulation temporarily improved the deficit in all patients. In cancelation tasks, omissions and performance asymmetries between the two hand-sides were reduced, as well as the rightward deviation in line bisection. Before TENS, SSVEP average latency to stimuli displayed in the left visual half-field [LVF (160 ms)] was remarkably longer than to stimuli shown in the right visual half-field [RVF (120 ms)]. Immediately after TENS, latency to LVF stimuli was 130 ms; 1 h after stimulation the effect of TENS faded, with latency returning to baseline. TENS similarly affected also the latency SSVEP of 12 healthy participants, and their line bisection performance, with effects smaller in size. The present study, first, replicates evidence concerning the positive behavioral effects of TENS on the manifestations of left USN in right-brain-damaged patients; second, it shows putatively related electrophysiological effects on the SSVEP latency. These behavioral and novel electrophysiological results are discussed in terms of specific directional effects of left somatosensory stimulation on egocentric coordinates, which in USN patients are displaced toward the side of the cerebral lesion. Showing that visual-evoked potentials latency is modulated by proprioceptive stimulation, we provide electrophysiological evidence to the effect that TENS may improve some manifestations of USN, with implications for its rehabilitation. PMID:23966919

Transcutaneous acupoint electrical stimulation pain management after surgical abortion: A cohort study.

PubMed

Feng, Xiaozhen; Ye, Tianshen; Wang, Zedong; Chen, Xiufang; Cong, Wenjie; Chen, Yong; Chen, Pinjie; Chen, Chong; Shi, Beibei; Xie, Wenxia

2016-06-01

Transcutaneous acupoint electrical stimulation (TEAS) is a standard therapy for painful conditions. This study evaluated pain-relieving effects of treatment with TEAS before and after surgical abortion. In this cohort study 140 nulliparae requesting pregnancy termination with intravenous anesthesia from August to December 2013 at the outpatient clinic of Wenzhou Medical University First Affiliated Hospital were recruited and divided into three cohorts who received TEAS pre-, post-, and both pre- and post-operation, alongside a control group. The cohorts underwent TEAS treatment for 30 min before and/or after the procedure while the control group received no TEAS treatment. Pain levels were evaluated upon recovery at 10, 30, and 45 min, respectively, after abortion. Mean Visual Analog Scale (VAS) scores in pre-operation cohorts, but not the post-operation cohort, were significantly lower than those obtained for the control group at 10 min (p < 0.01). VAS scores at 30 min and 45 min postoperatively were similar in each cohort but lower than control values (p < 0.001). More cohort patients reported mild or no pain than control patients (p < 0.05); the pre-operation cohorts had more women with no pain compared with the post-operation group (p < 0.05). There were no differences among groups in medical treatment required after 45 min. There were fewer complications of nausea and vomiting in the cohorts compared with the control group (p < 0.05). Performing TEAS before and after surgical abortion provides postoperative pain relief. However, receiving TEAS before surgery allowed more women to experience mild or no pain. Transcutaneous acupoint electrical stimulation shows potential as an adjunct to conventional pain treatment following surgical abortion in nulliparae. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Transcutaneous electrical nerve stimulation and acupuncture-like transcutaneous electrical nerve stimulation for chronic low back pain.

PubMed

Gadsby, J G; Flowerdew, M W

2000-01-01

Transcutaneous electrical nerve stimulation (TENS), originally based on the gate-control theory of pain, is widely used for the treatment of chronic low back pain. Despite its wide use and theoretical rationale, there appears at first glance little scientific evidence to support its use. This Cochrane review examines the available evidence on TENS for the treatment of chronic back pain through an exhaustive search of the literature. Transcutaneous electrical nerve stimulation (TENS) and acupuncture-like transcutaneous electrical nerve stimulation (ALTENS) for chronic low back pain management have experienced a tremendous growth over the past 25 years. The objective of this review was to assess the effects of TENS and ALTENS for reducing pain and improving function in patients with chronic back pain. We searched MEDLINE up to November 1997, EMBASE from 1985 to September 1995, Amed and Ciscom to January 1995, reference lists of the retrieved articles, proceedings of conferences and contacted investigators in the field. Randomised trials comparing TENS or ALTENS therapy to placebo in patients with chronic low back pain. Two reviewers independently assessed trial quality and extracted data on pain reduction, range of movement, functional and work status. Six trials were included. The trials included 288 participants with an average age range of 45 to 50 years and approximately equal numbers of women and men. The overall odds ratio for improvement in pain for each comparison was: TENS/ALTENS versus placebo 2.11 (95% confidence interval 1.32 to 3. 38), ALTENS versus placebo 7.22 (95% confidence interval 2.60 to 20.01) and TENS versus placebo 1.52 (95% confidence interval 0.90 to 2.58). The odds ration for improvement in range of motion on ALTENS versus placebo was 6.61 (95% confidence interval 2.36 to 18.55). There is evidence from the limited data available that TENS/ALTENS reduces pain and improves range of motion in chronic back pain patients, at least in the short term. A large trial of ALTENS and TENS is needed to confirm these findings.

Development of a high permeability cored transintegumental power transformer.

PubMed

Helmicki, A J; Melvin, D M; Henderson, H T; Nebrigic, D; Venkat, R; Glos, D L

1996-01-01

Circulatory support devices require 10-20 W. Currently, several devices are under development for the transmission of this power via transcutaneous transformers, with the secondary implanted subcutaneously and the primary worn externally. Because these devices are air cored, they have relatively large, bulky external appliances, poor coil to coil coupling, and result in significant stray fields passing through adjacent tissues. This article reports on the engineering design of a novel, high permeability cored transformer implanted in a transenteric configuration using an isolated intestinal pouch. Such an approach offers greater energy transmission efficiency, less heat dissipation, less stray electromagnetic energy, and greatly reduced device size. Two competing designs using this concept have been developed and tested. Each consists of the transformer, together with power interface electronics, forming a direct current (DC)/DC resonant converter. Operating frequencies are 90.2 and 14.7 kHz, respectively, with primary/secondary turns ratios of 10/10 and 11/14, respectively. In addition, data interface electronics allows communication across the transformer of up to four signals at a per channel sample rate of 10 Hz. Both designs are able to continuously transmit 25 W at an output level of 12 Vdc into a 5.8 omega load. Calorimetry tests indicate DC to DC efficiencies greater than 75% and coil to coil efficiencies greater than 96%. Total package size for the implantable portion of each device (including sensor internal interface electronics) is less than 40 ml, with a weight weight of less than 100 g. The results of short-term implantation studies have been favorable. Long-term implantation studies currently are under way.

Efficacy of Imiquimod-Based Transcutaneous Immunization Using a Nano-Dispersed Emulsion Gel Formulation

PubMed Central

Tenzer, Stefan; Schild, Hansjörg; Stevanovic, Stefan; Langguth, Peter; Radsak, Markus P.

2014-01-01

Background Transcutaneous immunization (TCI) approaches utilize skin associated lymphatic tissues to elicit specific immune responses. In this context, the imidazoquinoline derivative imiquimod formulated in Aldara applied onto intact skin together with a cytotoxic T lymphocyte (CTL) epitope induces potent CTL responses. However, the feasibility and efficacy of the commercial imiquimod formulation Aldara is limited by its physicochemical properties as well as its immunogenicity. Methodology/Principal Findings To overcome these obstacles, we developed an imiquimod-containing emulsion gel (IMI-Gel) and characterized it in comparison to Aldara for rheological properties and in vitro mouse skin permeation in a Franz diffusion cell system. Imiquimod was readily released from Aldara, while IMI-Gel showed markedly decreased drug release. Nevertheless, comparing vaccination potency of Aldara or IMI-Gel-based TCI in C57BL/6 mice against the model cytotoxic T-lymphocyte epitope SIINFEKL, we found that IMI-Gel was equally effective in terms of the frequency of peptide-specific T-cells and in vivo cytolytic activity. Importantly, transcutaneous delivery of IMI-Gel for vaccination was clearly superior to the subcutaneous or oral route of administration. Finally, IMI-Gel based TCI was at least equally effective compared to Aldara-based TCI in rejection of established SIINFEKL-expressing E.G7 tumors in a therapeutic setup indicated by enhanced tumor rejection and survival. Conclusion/Significance In summary, we developed a novel imiquimod formulation with feasible pharmaceutical properties and immunological efficacy that fosters the rational design of a next generation transcutaneous vaccination platform suitable for the treatment of cancer or persistent virus infections. PMID:25025233

Transcutaneous oxygen tension monitoring in critically ill patients receiving packed red blood cells.

PubMed

Schlager, Oliver; Gschwandtner, Michael E; Willfort-Ehringer, Andrea; Kurz, Martin; Mueller, Markus; Koppensteiner, Renate; Heinz, Gottfried

2014-12-01

Whether transfusions of packed red blood cells (PRBCs) affect tissue oxygenation in stable critically ill patients is still matter of discussion. The microvascular capacity for tissue oxygenation can be determined noninvasively by measuring transcutaneous oxygen tension (tcpO2). The aim of this study was to assess tissue oxygenation by measuring tcpO2 in stable critically ill patients receiving PRBC transfusions. Nineteen stable critically ill patients, who received 2 units of PRBC, were prospectively included into this pilot study. Transcutaneous oxygen tension was measured continuously during PRBC transfusions using Clark's electrodes. In addition, whole blood viscosity and global hemodynamics were determined. Reliable measurement signals during continuous tcpO2 monitoring were observed in 17 of 19 included patients. Transcutaneous oxygen tension was related to the global oxygen consumption (r=-0.78; P=.003), the arterio-venous oxygen content difference (r=-0.65; P=.005), and the extraction rate (r=-0.71; P=.02). The transfusion-induced increase of the hemoglobin concentration was paralleled by an increase of the whole blood viscosity (P<.001). Microvascular tissue oxygenation by means of tcpO2 was not affected by PRBC transfusions (P=.46). Packed red blood cell transfusions resulted in an increase of global oxygen delivery (P=.02) and central venous oxygen saturation (P=.01), whereas oxygen consumption remained unchanged (P=.72). In stable critically ill patients, microvascular tissue oxygenation can be continuously monitored by Clark's tcpO2 electrodes. According to continuous tcpO2 measurements, the microvascular tissue oxygenation is not affected by PRBC transfusions. Copyright © 2014 Elsevier Inc. All rights reserved.

Efficacy of electroacupuncture compared with transcutaneous electric nerve stimulation for functional constipation

PubMed Central

Zeng, Yuxiao; Zhang, Xuecheng; Zhou, Jing; Wang, Xinwei; Jiao, Ruimin; Liu, Zhishun

2018-01-01

Abstract Background: To treat functional constipation, both electroacupuncture (EA) therapy and transcutaneous electric nerve stimulation (TENS) are safe and effective. However, no head-to-head comparison trial has been conducted. This trial compares the efficacy of electroacupuncture relative to transcutaneous electric nerve stimulation for functional constipation. Methods: Individuals with functional constipation will be randomly allocated to receive either EA or TENS (n = 51, each), 3 times per week for 8 weeks. The primary outcome is the percentage of participants with an average increase from baseline of 1 or more complete spontaneous bowel movements at week 8. The secondary outcome measures are the following: at the time of visits, changes in the number of complete spontaneous bowel movements, number of spontaneous bowel movements, stool character, difficulty in defecation, patients’ assessment of quality of life regarding constipation (self-report questionnaire), and use of auxiliary defecation methods. Discussion: The results of this trial should verify whether EA is more efficacious than TENS for relieving symptoms of functional constipation. The major limitation of the study is the lack of blinding of the participants and acupuncturist. PMID:29742718

Assessment: efficacy of transcutaneous electric nerve stimulation in the treatment of pain in neurologic disorders (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

PubMed

Dubinsky, Richard M; Miyasaki, Janis

2010-01-12

To determine if transcutaneous electric nerve stimulation (TENS) is efficacious in the treatment of pain in neurologic disorders. We performed a systematic literature search of Medline and the Cochrane Library from inception to April 2009. There are conflicting reports of TENS compared to sham TENS in the treatment of chronic low back pain, with 2 Class II studies showing benefit, but 2 Class I studies and another Class II study not showing benefit. Because the Class I studies are stronger evidence, TENS is established as ineffective for the treatment of chronic low back pain (2 Class I studies). TENS is probably effective in treating painful diabetic neuropathy (2 Class II studies). Transcutaneous electric nerve stimulation (TENS) is not recommended for the treatment of chronic low back pain (Level A). TENS should be considered in the treatment of painful diabetic neuropathy (Level B). Further research into the mechanism of action of TENS is needed, as well as more rigorous studies for determination of efficacy.

Efficacy of electroacupuncture compared with transcutaneous electric nerve stimulation for functional constipation: Study protocol for a randomized, controlled trial.

PubMed

Zeng, Yuxiao; Zhang, Xuecheng; Zhou, Jing; Wang, Xinwei; Jiao, Ruimin; Liu, Zhishun

2018-05-01

To treat functional constipation, both electroacupuncture (EA) therapy and transcutaneous electric nerve stimulation (TENS) are safe and effective. However, no head-to-head comparison trial has been conducted. This trial compares the efficacy of electroacupuncture relative to transcutaneous electric nerve stimulation for functional constipation. Individuals with functional constipation will be randomly allocated to receive either EA or TENS (n = 51, each), 3 times per week for 8 weeks. The primary outcome is the percentage of participants with an average increase from baseline of 1 or more complete spontaneous bowel movements at week 8. The secondary outcome measures are the following: at the time of visits, changes in the number of complete spontaneous bowel movements, number of spontaneous bowel movements, stool character, difficulty in defecation, patients' assessment of quality of life regarding constipation (self-report questionnaire), and use of auxiliary defecation methods. The results of this trial should verify whether EA is more efficacious than TENS for relieving symptoms of functional constipation. The major limitation of the study is the lack of blinding of the participants and acupuncturist.

Influence of heat and moisture exchanger respiratory load on transcutaneous oxygenation in laryngectomized individuals: a randomized crossover study.

PubMed

Zuur, J Karel; Muller, Sara H; Sinaasappel, Michiel; Hart, Guus A M; van Zandwijk, Nico; Hilgers, Frans J M

2007-12-01

High-resistance heat and moisture exchangers (HMEs) have been reported to increase transcutaneous oxygenation (tcpO(2)) values in laryngectomized individuals and to negatively influence patient compliance. The goal of the present study was to validate earlier published results on short-term transcutaneous oxygenation changes by high-resistance HMEs. We conducted a randomized crossover study, monitoring the influence of an HME on tcpO(2) over a 2-hour time interval in 20 subjects. No evidence of an immediate HME effect (95% CI: -14.9-13.3 mm Hg, p = .91), or a time-dependent HME effect (95% CI: -.121 - .172 mm Hg/minute, p = .74), on tcpO(2) was found. After fitting the statistical model without time dependency, again no evidence of HME presence was seen (95% CI: -.5 mm Hg - 3.6 mm Hg, p = .15). In contrast to earlier suggestions, there is no evidence of increased tcpO(2) levels by high-resistance HMEs in laryngectomized individuals. Thus, using such HMEs has no added clinical value in this respect.

Longitudinal, transcranial measurement of functional activation in the rat brain by diffuse correlation spectroscopy.

PubMed

Blanco, Igor; Zirak, Peyman; Dragojević, Tanja; Castellvi, Clara; Durduran, Turgut; Justicia, Carles

2017-10-01

Neural activity is an important biomarker for the presence of neurodegenerative diseases, cerebrovascular alterations, and brain trauma; furthermore, it is a surrogate marker for treatment effects. These pathologies may occur and evolve in a long time-period, thus, noninvasive, transcutaneous techniques are necessary to allow a longitudinal follow-up. In the present work, we have customized noninvasive, transcutaneous, diffuse correlation spectroscopy (DCS) to localize changes in cerebral blood flow (CBF) induced by neural activity. We were able to detect changes in CBF in the somatosensory cortex by using a model of electrical forepaw stimulation in rats. The suitability of DCS measurements for longitudinal monitoring was demonstrated by performing multiple sessions with the same animals at different ages (from 6 to 18 months). In addition, functional DCS has been cross-validated by comparison with functional magnetic resonance imaging (fMRI) in the same animals in a subset of the time-points. The overall results obtained with transcutaneous DCS demonstrates that it can be utilized in longitudinal studies safely and reproducibly to locate changes in CBF induced by neural activity in the small animal brain.

Reinstatement of contextual conditioned anxiety in virtual reality and the effects of transcutaneous vagus nerve stimulation in humans.

PubMed

Genheimer, Hannah; Andreatta, Marta; Asan, Esther; Pauli, Paul

2017-12-20

Since exposure therapy for anxiety disorders incorporates extinction of contextual anxiety, relapses may be due to reinstatement processes. Animal research demonstrated more stable extinction memory and less anxiety relapse due to vagus nerve stimulation (VNS). We report a valid human three-day context conditioning, extinction and return of anxiety protocol, which we used to examine effects of transcutaneous VNS (tVNS). Seventy-five healthy participants received electric stimuli (unconditioned stimuli, US) during acquisition (Day1) when guided through one virtual office (anxiety context, CTX+) but never in another (safety context, CTX-). During extinction (Day2), participants received tVNS, sham, or no stimulation and revisited both contexts without US delivery. On Day3, participants received three USs for reinstatement followed by a test phase. Successful acquisition, i.e. startle potentiation, lower valence, higher arousal, anxiety and contingency ratings in CTX+ versus CTX-, the disappearance of these effects during extinction, and successful reinstatement indicate validity of this paradigm. Interestingly, we found generalized reinstatement in startle responses and differential reinstatement in valence ratings. Altogether, our protocol serves as valid conditioning paradigm. Reinstatement effects indicate different anxiety networks underlying physiological versus verbal responses. However, tVNS did neither affect extinction nor reinstatement, which asks for validation and improvement of the stimulation protocol.

Mixed evidence for the potential of non-invasive transcutaneous vagal nerve stimulation to improve the extinction and retention of fear.

PubMed

Burger, A M; Verkuil, B; Fenlon, H; Thijs, L; Cools, L; Miller, H C; Vervliet, B; Van Diest, I

2017-10-01

Extinction memories are fragile and their formation has been proposed to partially rely on vagus nerve activity. We tested whether stimulating the auricular branch of the vagus (transcutaneous VNS; tVNS) accelerates extinction and reduces spontaneous recovery of fear. Forty-two healthy students participated in a 3-day fear conditioning study, where we tested fear acquisition (day 1), fear extinction (day 2) and the retention of the extinction memory (day 3). During extinction, participants were randomly allocated to receive tVNS or sham stimulation concurrently with each CS presentation. During the acquisition and retention phases, all participants received sham stimulation. Indexes of fear included US-expectancy, startle blink EMG and skin conductance responses. Results showed successful acquisition and extinction of fear in all measures. tVNS facilitated the extinction of declarative fear (US expectancy ratings), but did not promote a stronger retention of the declarative extinction memory. No clear effects of tVNS on extinction and retention of extinction were found for the psychophysiological indexes. The present findings provide tentative indications that tVNS could be a promising tool to improve fear extinction and call for larger scale studies to replicate these effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

DERMAL DRUG LEVELS OF ANTIBIOTIC (CEPHALEXIN) DETERMINED BY ELECTROPORATION AND TRANSCUTANEOUS SAMPLING (ETS) TECHNIQUE

PubMed Central

Sammeta, SM; Vaka, SRK; Murthy, S. Narasimha

2009-01-01

The purpose of this project was to assess the validity of a novel “Electroporation and transcutaneous sampling (ETS)” technique for sampling cephalexin from the dermal extracellular fluid (ECF). This work also investigated the plausibility of using cephalexin levels in the dermal ECF as a surrogate for the drug level in the synovial fluid. In vitro and in vivo studies were carried out using hair less rats to assess the workability of ETS. Cephalexin (20mg/kg) was administered i.v. through tail vein and the time course of drug concentration in the plasma was determined. In the same rats, cephalexin concentration in the dermal ECF was determined by ETS and microdialysis techniques. In a separate set of rats, only intraarticular microdialysis was carried out determine the time course of cephalexin concentration in synovial fluid. The drug concentration in the dermal ECF determined by ETS and microdialysis did not differ significantly from each other and so as were the pharmacokinetic parameters. The results provide validity to the ETS technique. Further, there was a good correlation (~0.9) between synovial fluid and dermal ECF levels of cephalexin indicating that dermal ECF levels could be used as a potential surrogate for cephalexin concentration in the synovial fluid. PMID:19067398

Transcutaneous monitoring of steroid-induced osteoporosis with Raman spectroscopy

NASA Astrophysics Data System (ADS)

Maher, Jason R.; Inzana, Jason; Takahata, Masahiko; Awad, Hani A.; Berger, Andrew J.

2012-01-01

Although glucocorticoids are among the most frequently prescribed anti-inflammatory agents used in the treatment of rheumatoid arthritis, extended exposure to this steroid hormone is the leading cause of iatrogenic osteoporosis. Recently, Raman spectroscopy has been utilized to exploit biochemical differences between osteoporotic and normal bones in order to predict fracture risk. In this presentation, we report the results of ongoing research in our laboratory towards the clinical translation of this technique. We will discuss strategies for the transcutaneous acquisition of spectra from the tibiae of mice that are of sufficient quality to generate accurate predictions of fracture risk.

Neuralgia associated with transcutaneous electrical nerve stimulation therapy in a patient initially diagnosed with temporomandibular disorder.

PubMed

Omolehinwa, Temitope T; Musbah, Thamer; Desai, Bhavik; O'Malley, Bert W; Stoopler, Eric T

2015-03-01

Head and neck neoplasms may be difficult to detect because of wide-ranging symptoms and the presence of overlapping anatomic structures in the region. This case report describes a patient with chronic otalgia and temporomandibular disorder, who developed sudden-onset neuralgia while receiving transcutaneous electrical nerve stimulation (TENS) therapy. Further diagnostic evaluation revealed a skull base tumor consistent with adenoid cystic carcinoma. To our knowledge, this is the first report of TENS-associated neuralgia leading to a diagnosis of primary intracranial adenoid cystic carcinoma. Copyright © 2015 Elsevier Inc. All rights reserved.

A 32-channel fully implantable wireless neurosensor for simultaneous recording from two cortical regions.

PubMed

Aceros, Juan; Yin, Ming; Borton, David A; Patterson, William R; Nurmikko, Arto V

2011-01-01

We present a fully implantable, wireless, neurosensor for multiple-location neural interface applications. The device integrates two independent 16-channel intracortical microelectrode arrays and can simultaneously acquire 32 channels of broadband neural data from two separate cortical areas. The system-on-chip implantable sensor is built on a flexible Kapton polymer substrate and incorporates three very low power subunits: two cortical subunits connected to a common subcutaneous subunit. Each cortical subunit has an ultra-low power 16-channel preamplifier and multiplexer integrated onto a cortical microelectrode array. The subcutaneous epicranial unit has an inductively coupled power supply, two analog-to-digital converters, a low power digital controller chip, and microlaser-based infrared telemetry. The entire system is soft encapsulated with biocompatible flexible materials for in vivo applications. Broadband neural data is conditioned, amplified, and analog multiplexed by each of the cortical subunits and passed to the subcutaneous component, where it is digitized and combined with synchronization data and wirelessly transmitted transcutaneously using high speed infrared telemetry.

Development of a near-infrared spectroscopy instrument for applications in urology.

PubMed

Macnab, Andrew J; Stothers, Lynn

2008-10-01

Near infrared spectroscopy (NIRS) is an established technology using photons of light in the near infrared spectrum to monitor changes in tissue of naturally occurring chromophores, including oxygenated and deoxygenated hemoglobin. Technology and methodology have been validated for measurement of a range of physiologic parameters. NIRS has been applied successfully in urology research; however current instruments are designed principally for brain and muscle study. To describe development of a NIRS instrument specifically designed for monitoring changes in chromophore concentration in the bladder detrusor in real time, to facilitate research to establish the role of this non-invasive technology in the evaluation of patients with voiding dysfunction The portable continuous wave NIRS instrument has a 3 laser diode light source (785, 808 and 830 nanometers), fiber optic cables for light transmission, a self adhesive patient interface patch with an emitter and sensor, and software to detect the difference between the light transmitted and received by the instrument. Software incorporated auto-attenuates the optical signals and converts raw optical data into chromophore concentrations displayed graphically. The prototype was designed, tested, and iteratively developed to achieve optimal suprapubic transcutaneous monitoring of the detrusor in human subjects during bladder filling and emptying. Evaluation with simultaneous invasive urodynamic measurement in men and women indicates good specificity and sensitivity of NIRS chromophore concentration changes by receiver operator curve analysis, and correlation between NIRS data and urodynamic pressures. Urological monitoring with this NIRS instrument is feasible and generates data of potential diagnostic value.

Transcutaneous yellow fever vaccination of subjects with or without atopic dermatitis

PubMed Central

Slifka, Mark K.; Leung, Donald Y. M.; Hammarlund, Erika; Raué, Hans-Peter; Simpson, Eric L.; Tofte, Susan; Baig-Lewis, Shahana; David, Gloria; Lynn, Henry; Woolson, Rob; Hata, Tissa; Milgrom, Henry; Hanifin, Jon

2013-01-01

Background Atopic dermatitis (AD) is a common inflammatory skin disease with global prevalence ranging from 3% to 20%. AD patients have an increased risk for complications following viral infection (e.g., herpes simplex virus), and vaccination of AD patients with live vaccinia virus is contraindicated due to a heightened risk of eczema vaccinatum, a rare but potentially lethal complication associated with smallpox vaccination. Objective To develop a better understanding of immunity to cutaneous viral infection in AD patients. Methods In a double-blind, randomized study, we investigated the safety and immunogenicity of live attenuated yellow fever virus (YFV) vaccination of non-atopic (NA) subjects and AD patients following standard subcutaneous (SC) inoculation or transcutaneous (TC) vaccination administered with a bifurcated needle. Viremia, neutralizing antibody, and antiviral T cell responses were analyzed for up to 30 days post-vaccination. Results YFV vaccination by either route was well tolerated. SC vaccination resulted in higher seroconversion rates than TC vaccination but elicited similar antiviral antibody levels and T cell responses in both NA and AD groups. Following TC vaccination, both groups mounted similar neutralizing antibody responses, but AD patients demonstrated lower antiviral T cell responses by 30 days after vaccination. Among TC-vaccinated subjects, a significant inverse correlation between baseline IgE levels and the magnitude of antiviral antibody and CD4+ T cell responses was observed. Conclusions YFV vaccination of AD patients by the TC route revealed that high baseline IgE levels provides a potential biomarker for predicting reduced virus-specific immune memory following TC infection with a live virus. PMID:24331381

Transcutaneous Electrical Nerve Stimulation Improves Walking Performance in Patients With Intermittent Claudication.

PubMed

Seenan, Chris; McSwiggan, Steve; Roche, Patricia A; Tan, Chee-Wee; Mercer, Tom; Belch, Jill J F

2016-01-01

The purpose of this study was to investigate the effects of 2 types of transcutaneous electrical nerve stimulation (TENS) on walking distance and measures of pain in patients with peripheral arterial disease (PAD) and intermittent claudication (IC). In a phase 2a study, 40 participants with PAD and IC completed a graded treadmill test on 2 separate testing occasions. Active TENS was applied to the lower limb on the first occasion; and placebo TENS, on the second. The participants were divided into 2 experimental groups. One group received high-frequency TENS; and the other, low-frequency TENS. Measures taken were initial claudication distance, functional claudication distance, and absolute claudication distance. The McGill Pain Questionnaire (MPQ) vocabulary was completed at the end of the intervention, and the MPQ-Pain Rating Index score was calculated. Four participants were excluded from the final analysis because of noncompletion of the experimental procedure. Median walking distance increased with high-frequency TENS for all measures (P < .05, Wilcoxon signed rank test, all measures). Only absolute claudication distance increased significantly with low-frequency TENS compared with placebo (median, 179-228; Ws = 39; z = 2.025; P = .043; r = 0.48). No difference was observed between reported median MPQ-Pain Rating Index scores: 21.5 with placebo TENS and 21.5 with active TENS (P = .41). Transcutaneous electrical nerve stimulation applied to the lower limb of the patients with PAD and IC was associated with increased walking distance on a treadmill but not with any reduction in pain. Transcutaneous electrical nerve stimulation may be a useful adjunctive intervention to help increase walking performance in patients with IC.

The influence of massage on neonatal hyperbilirubinemia: a meta-analysis of randomized controlled trials.

PubMed

Zhang, Min; Wang, Lili; Wang, Yang; Tang, Jiulai

2018-04-09

The efficacy of massage to treat neonatal hyperbilirubinemia remains controversial. We conducted a systematic review and meta-analysis to explore the influence of massage on the neonatal hyperbilirubinemia. We search PubMed, Embase, Web of science, EBSCO, and Cochrane Library databases through November 2017 for randomized controlled trials (RCTs) assessing the effect of massage on neonatal hyperbilirubinemia. This meta-analysis is performed using the random-effect model. Six RCTs involving 357 patients are included in the meta-analysis. Overall, compared with the control group in neonatal hyperbilirubinemia, massage therapy is associated with substantially reduced serum bilirubin level within 4 d (mean difference (MD) = -2.31; 95% CI = -2.92 to -1.70; p < .00001) and transcutaneous bilirubin level within 4 d for neonatal hyperbilirubinemia (MD = -1.97; 95% CI = -2.55 to -1.39; p < .00001), but results no remarkable impact on serum bilirubin level on 2 d (MD = -0.82; 95% CI = -2.16-0.52; p = .23), transcutaneous bilirubin level on 2 d (MD = -0.17; 95% CI = -1.34 to 1.00; p = .77), frequency of defecation daily on 2 d (MD = 0.57; 95% CI = -0.03 to 1.16; p = .06), and frequency of defecation daily within 4 d (MD = 0.83; 95% CI = -0.11 to 1.76; p = .08). Massage therapy can significantly reduce serum bilirubin level and transcutaneous bilirubin level within 4 d, but demonstrates no influence on serum bilirubin level and transcutaneous bilirubin level on 2 d, frequency of defecation daily on 2 and 4 d for neonatal hyperbilirubinemia.

Evaluation of peripheral microcirculation improvement of foot after tarsal tunnel release in diabetic patients by transcutaneous oximetry.

PubMed

Trignano, Emilio; Fallico, Nefer; Chen, Hung-Chi; Faenza, Mario; Bolognini, Alfonso; Armenti, Andrea; Santanelli Di Pompeo, Fabio; Rubino, Corrado; Campus, Gian Vittorio

2016-01-01

According to recent studies, peripheral nerve decompression in diabetic patients seems to not only improve nerve function, but also to increase microcirculation; thus decreasing the incidence of diabetic foot wounds and amputations. However, while the postoperative improvement of nerve function is demonstrated, the changes in peripheral microcirculation have not been demonstrated yet. The aim of this study is to assess the degree of microcirculation improvement of foot after the tarsal tunnel release in the diabetic patients by using transcutaneous oximetry. Twenty diabetic male patients aged between 43 and 72 years old (mean age 61.2 years old) suffering from diabetic peripheral neuropathy with superimposed nerve compression underwent transcutaneous oximetry (PtcO2) before and after tarsal tunnel release by placing an electrode on the skin at the level of the dorsum of the foot. Eight lower extremities presented diabetic foot wound preoperatively. Thirty-six lower extremities underwent surgical release of the tibialis posterior nerve only, whereas four lower extremities underwent the combined release of common peroneal nerve, anterior tibialis nerve, and posterior tibialis nerve. Preoperative values of transcutaneous oximetry were below the critical threshold, that is, lower than 40 mmHg (29.1 ± 5.4 mmHg). PtcO2 values at one month after surgery (45.8 ± 6.4 mmHg) were significantly higher than the preoperative ones (P = 0.01). The results of postoperative increase in PtcO2 values demonstrate that the release of the tarsal tunnel determines a relevant increase in microcirculation in the feet of diabetic patients. © 2015 Wiley Periodicals, Inc.

PubMed Central

MARSELLA, P.; DALMASSO, G.; PACIFICO, C.

2015-01-01

SUMMARY Since 2011, transcutaneous bone-anchored auditory implants have been an alternative to the classic percutaneous implant (Baha) for bilateral conductive/mixed hearing loss that cannot be corrected by surgery. Recently, a new transcutaneous device has been approved for clinical use. Its internal component is made of the classic titanium Baha fixture, coupled to a 27 mm diameter subcutaneous circular magnet. The external component includes a second circular magnet 29 mm in diameter and a digital sound processor. To date, there are no reports describing the results of the application of this device. The aim of the present study is to report on the anatomical and functional results of transcutaneous Baha implantation in three patients: two adults, one with syndromic aural atresia and one with bilateral conductive hearing loss due to bilateral tympanomastoidectomy, and an 8-year-old child with non-syndromic aural atresia. No major intraoperative or postoperative complications were observed. The three patients tolerated the external magnet, with no signs of skin irritation. Functional results were good: median unaided free-field PTA (0.5-3 kHz) was 50 dB HL (range = 41-66 dB HL); with the transcutaneous Baha median PTA (0.5-3 kHz) was 27 dB HL (range = 25-30 dB HL) and median gain was 25 dB HL (range = 11-39 dB HL). Preliminary results encourage use of the device as a valuable alternative to other implantable devices in these patients. To ensure the success of treatment, several precautions are suggested including gradually increasing use during the first post-operative months to favour skin adaptation to magnet pressure. In addition to skin reactions, in a paediatric age most concerns are related to the curvature of the skull, which may induce tenting of the skin over the internal magnet. PMID:26015648

Transcutaneous Raman Spectroscopy of Bone

NASA Astrophysics Data System (ADS)

Maher, Jason R.

Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral differences in murine bone.

Effect of transcutaneous electrical stimulation amplitude on timing of swallow pressure peaks between healthy young and older adults.

PubMed

Barikroo, Ali; Berretin-Felix, Giedré; Carnaby, Giselle; Crary, Michael

2017-03-01

This study compared the effect of transcutaneous electrical stimulation (TES) amplitude on timing of lingual-palatal and pharyngeal peak pressures during swallowing in healthy younger and older adults. Transcutaneous electrical stimulation amplitude is one parameter that may have different impacts on the neuromotor system and swallowing physiology. One aspect of swallowing physiology influenced by age is the timing of swallowing events. However, the effect of varying TES amplitudes on timing of swallowing physiology is poorly understood, especially in older adults. Thirty-four adults (20 younger and 14 older) swallowed 10 ml of nectar-thick liquid under three TES conditions: no stimulation, low-amplitude stimulation and high-amplitude stimulation. TES was delivered by surface electrodes on the anterior neck. Timing of pressure peaks for lingual-palatal contacts and pharyngeal pressures were measured under each condition. A significant age × stimulation amplitude interaction was identified for the base of tongue (BOT) [F(2,62) = 5.087, p < 0.009] and the hypopharynx (HYPO) [F(2,62) = 3.277, p < 0.044]. At the BOT, low-amplitude TES resulted in slower swallows in the younger adults compared with no TES. In older adults, low-amplitude TES resulted in faster swallows compared with high-amplitude TES. At the HYPO, no significant differences were identified in pressure timing across the three TES amplitudes in both age groups. In each case, low-amplitude TES resulted in faster swallows in older adults compared with younger adults. Transcutaneous electrical stimulation influences pharyngeal pressure timing differently in young and old people, which questions the appropriateness of using a 'one-size-fits-all' TES amplitude for rehabilitating people with dysphagia. © 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Characterization of evoked tactile sensation in forearm amputees with transcutaneous electrical nerve stimulation

NASA Astrophysics Data System (ADS)

Chai, Guohong; Sui, Xiaohong; Li, Si; He, Longwen; Lan, Ning

2015-12-01

Objective. The goal of this study is to characterize the phenomenon of evoked tactile sensation (ETS) on the stump skin of forearm amputees using transcutaneous electrical nerve stimulation (TENS). Approach. We identified the projected finger map (PFM) of ETS on the stump skin in 11 forearm amputees, and compared perceptual attributes of the ETS in nine forearm amputees and eight able-bodied subjects using TENS. The profile of perceptual thresholds at the most sensitive points (MSPs) in each finger-projected area was obtained by modulating current amplitude, pulse width, and frequency of the biphasic, rectangular current stimulus. The long-term stability of the PFM and the perceptual threshold of the ETS were monitored in five forearm amputees for a period of 11 months. Main results. Five finger-specific projection areas can be independently identified on the stump skin of forearm amputees with a relatively long residual stump length. The shape of the PFM was progressively similar to that of the hand with more distal amputation. Similar sensory modalities of touch, pressure, buzz, vibration, and numb below pain sensation could be evoked both in the PFM of the stump skin of amputees and in the normal skin of able-bodied subjects. Sensory thresholds in the normal skin of able-bodied subjects were generally lower than those in the stump skin of forearm amputees, however, both were linearly modulated by current amplitude and pulse width. The variation of the MSPs in the PFM was confined to a small elliptical area with 95% confidence. The perceptual thresholds of thumb-projected areas were found to vary less than 0.99 × 10-2 mA cm-2. Significance. The stable PFM and sensory thresholds of ETS are desirable for a non-invasive neural interface that can feed back finger-specific tactile information from the prosthetic hand to forearm amputees.

Transcutaneous Electrical Nerve Stimulation (TENS) A Possible Aid for Pain Relief in Developing Countries?

PubMed Central

Tashani, O; Johnson, MI

2009-01-01

Transcutaneous electrical nerve stimulation (TENS) refers to the delivery of electrical currents through the skin to activate peripheral nerves. The technique is widely used in developed countries to relieve a wide range of acute and chronic pain conditions, including pain resulting from cancer and its treatment. There are many systematic reviews on TENS although evidence is often inconclusive because of shortcomings in randomised control trials methodology. In this overview the basic science behind TENS will be discussed, the evidence of its effectiveness in specific clinical conditions analysed and a case for its use in pain management in developing countries will be made. PMID:21483510

Transcutaneous closure of chronic broncho-pleuro-cutaneous fistula by duct occluder device

PubMed Central

Marwah, Vikas; Ravikumar, R; Rajput, Ashok Kumar; Singh, Amandeep

2016-01-01

Bronchopleural fistula (BPF) is a well known complication of several pulmonary conditions posing challenging management problem and is often associated with high morbidity and mortality. Though no consensus exists on a definite closure management algorithm, strategies for closure widely include various methods like tube thoracostomy with suction, open surgical closure, bronchoscopy directed glue, coiling and sealants which now also includes use of occlusion devices. We report a case in which a novel method of delivery and closure of recurrent post-operative broncho-pleuro-cutaneous fistula by a duct occluder device was done transcutaneously which has not been previously described in literature. PMID:27051115

Lower limb sympathectomy assessed by laser Doppler blood flow and transcutaneous oxygen measurements.

PubMed

Lantsberg, L; Goldman, M

1990-01-01

In a retrospective study of critical ischaemia of the lower limb, sympathectomy appeared to be of value in the majority of patients. We therefore assessed sympathectomy by measuring skin blood flow before and after the procedure using laser Doppler flowmetry (LDF) and transcutaneous oxygen tension (TCpO2) techniques. Twenty patients underwent chemical sympathectomy and there was one surgical procedure. Measurements were performed before and 1 week after sympathectomy below the knee and on the forefoot. Symptomatic improvement occurred in 20 of 21 patients. This study demonstrates that skin blood flow in the leg and foot is improved by sympathectomy and confirms objectively our clinical impression.

Particle based vaccine formulations for transcutaneous immunization.

PubMed

Mittal, Ankit; Raber, Anne S; Lehr, Claus-Michael; Hansen, Steffi

2013-09-01

Vaccine formulations on the basis of nano- (NP) or microparticles (MP) can solve issues with stabilization, controlled release, and poor immunogenicity of antigens. Likewise transcutaneous immunization (TCI) promises superior immunogenicity as well as the advantages of needle-free application compared with conventional intramuscular injections. Thus the combination of both strategies seems to be a very valuable approach. However, until now TCI using particle based vaccine formulations has made no impact on medical practice. One of the main difficulties is that NPs and MPs cannot penetrate the skin to an extent that would allow the application of the required dose of antigen. This is due to the formidable stratum corneum (SC) barrier, the limited amount of antigen in the formulation and often an insufficient immunogenicity. A multitude of strategies are currently under investigation to overcome these issues. We highlight selected methods presenting a spectrum of solutions ranging from transfollicular delivery, to devices disrupting the SC barrier and the combination of particle based vaccines with adjuvants discussing their advantages and shortcomings. Some of these are currently at an experimental state while others are already in clinical testing. All methods have been shown to be capable of transcutaneous antigen delivery.

The effect of massage on neonatal jaundice in stable preterm newborn infants: a randomized controlled trial.

PubMed

Basiri-Moghadam, Mahdi; Basiri-Moghadam, Kokab; Kianmehr, Mojtaba; Jani, Somaye

2015-06-01

To evaluate the effects of massage therapy on transcutaneous bilirubin of stable preterm infants. The controlled clinical trial was conducted in 2014 at Shahid Hasheminejhad Hospital, Iran, and comprised preterm neonatal children in the neonatal intensive care unit. The newborns were divided into two groups of massage and control via random allocation. The children in the control group received the routine therapy whereas those in the massage group underwent the same four days of routine plus 20 minutes of massage twice a day. The transcutaneous bilirubin and the number of excretions of the newborns were noted from the first to the fourth day of the intervention and results were compared between the two groups. There were 40 newborns in the study l 20(50%) each in the two groups. There was a significant difference in the number of times of defecation (p=0.002) and in the level of bilirubin (p=0.003) between the groups with those in the massage group having a higher number of defecations as well as a lower level of transcutaneous bilirubin. Through massage therapy the bilirubin level in preterm newborns can be controlled and a need for phototherapy can also be delayed.

Dynamic analysis of modified transcutaneous lower blepharoplasty based on biochemical and biophysical principles.

PubMed

Liao, Chuh-Kai; Tsai, Feng-Chou; Fong, Tsorng-Harn; Huang, Chin-Ju; Shen, Yi-Chin; Ku, Yuan-Hao; Su, Ching-Hua

2013-12-01

In this study, we analyzed the key parameters of modified transcutaneous lower blepharoplasty based on multidisciplinary principles (biochemical findings and biophysical wrinkling theory). A total of 408 female patients received our subciliary lower blepharoplasty between March 2002 and January 2010. The severity of the eyebags (dynamic wrinkle numbers and prolapse) was evaluated through preoperative and postoperative photography, whereas the excised lower eyelid skin specimens from 56 patients were investigated with hematoxylin and eosin staining. The modified techniques produced significant improvements in the severity of eyebags in all age groups (P < 0.001). Poor surgical outcome was found to correlate significantly with preoperative dynamic wrinkle numbers (P < 0.001). Age, dynamic wrinkle numbers, and prolapse correlated significantly with dermal fiber density (P = 0.004, 0.000, and 0.000, respectively) but not epidermal, rete ridge, and dermal thickness or the number of rete ridges. In conclusion, modified transcutaneous lower blepharoplasty provides significant improvement to dynamic wrinkles and prolapse in the eyebags. Periorbital aging progressively disturbs the dermal compactness (fiber density) until the structure can no longer hold its integrity at the critical age (around the age of 40).

Traditional transcutaneous approaches in head and neck surgery

PubMed Central

Goessler, Ulrich R.

2012-01-01

The treatment of laryngeal and hypopharyngeal malignancies remains a challenging task for the head and neck surgeon as the chosen treatment modality often has to bridge the gap between oncologically sound radicality and preservation of function. Due to the increase in transoral laser surgery in early tumor stages and chemoradiation in advanced stages, the usage of traditional transcutaneous approaches has decreased over the recent past. In addition, the need for a function-sparing surgical approach as well as highest possible quality of life has become evident. In view of these facts, rationale and importance of traditional transcutaneous approaches to the treatment of laryngeal and hypopharyngeal malignancies are discussed in a contemporary background. The transcutaneous open partial laryngectomies remain a valuable tool in the surgeon's armamentarium for the treatment of early and advanced laryngeal carcinomas, especially in cases of impossible laryngeal overview using the rigid laryngoscope. Open partial laryngetomies offer superior overview and oncologic safety at the anterior commissure, especially in recurrencies. In select advanced cases and salvage settings, the supracricoid laryngectomy offers a valuable tool for function-preserving but oncologically safe surgical therapy at the cost of high postoperative morbidity and a very demanding rehabilitation of swallowing. In hypopharyngeal malignancies, the increasing use of transoral laser surgery has led to a decline in transcutaneous resections via partial pharyngectomy with partial laryngectomy in early tumor stages. In advanced stages of tumors of the piriform sinus and the postcricoid area with involvement of the larynx, total laryngectomy with partial pharyngectomy is an oncologically safe approach. The radical surgical approach using circumferent laryngopharyngectomy with/without esophagectomy is indicated in salvage cases with advanced recurrences or as a primary surgical approach in patients where chemoradiation does not offer sufficient oncologic control or preservation of function. In cases with impending reconstruction, fasciocutaneous free flaps (anterolateral thigh flap, radial forearm flap) seem to offer superior results to enteric flaps in cases where the cervical esophagus is not involved leading to better voice rehabilitation with fewer complications and postoperative morbidity. In salvage situations, the Gastroomental Free Flap has proven to be a valuable tool. In conclusion, the choice of a surgical treatment modality is influenced by the patient's anatomy, tumor size and location as well as the surgeon's personal expertise. PMID:23320058

Transcutaneous stimulation of the posterior tibial nerve for treating refractory urge incontinence of idiopathic and neurogenic origin.

PubMed

Valles-Antuña, C; Pérez-Haro, M L; González-Ruiz de L, C; Quintás-Blanco, A; Tamargo-Diaz, E M; García-Rodríguez, J; San Martín-Blanco, A; Fernandez-Gomez, J M

2017-09-01

To assess the efficacy of treatment with transcutaneous posterior tibial nerve stimulation (TPTNS) in patients with urge urinary incontinence, of neurogenic or nonneurogenic origin, refractory to first-line therapeutic options. We included 65 patients with urge urinary incontinence refractory to medical treatment. A case history review, a urodynamic study and a somatosensory evoked potentials (SEP) study were conducted before the TPTNS, studying the functional urological condition by means of a voiding diary. The treatment consisted of 10 weekly sessions of TPTNS lasting 30minutes. Some 57.7% of the patients showed abnormal tibial SEPs, and 42% showed abnormal pudendal SEPs. A statistically significant symptomatic improvement was observed in all clinical parameters after treatment with TPTNS, and 66% of the patients showed an overall improvement, regardless of sex, the presence of underlying neurological disorders, detrusor hyperactivity in the urodynamic study or SEP disorders. There were no adverse effects during the treatment. TPTNS is an effective and well tolerated treatment in patients with urge incontinence refractory to first-line therapies and should be offered early in the treatment strategy. New studies are needed to identify the optimal parameters of stimulation, the most effective treatment protocols and long-term efficacy, as well as its applicability to patients with a neurogenic substrate. Copyright © 2017 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Noninvasive glucose sensing by transcutaneous Raman spectroscopy

NASA Astrophysics Data System (ADS)

Shih, Wei-Chuan; Bechtel, Kate L.; Rebec, Mihailo V.

2015-05-01

We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ˜1.5-2 mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies.

Noninvasive glucose sensing by transcutaneous Raman spectroscopy.

PubMed

Shih, Wei-Chuan; Bechtel, Kate L; Rebec, Mihailo V

2015-05-01

We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ~1.5-2  mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies.

Direct and Indirect Benefits Reported by Users of Transcutaneous Electrical Nerve Stimulation for Chronic Musculoskeletal Pain: Qualitative Exploration Using Patient Interviews.

PubMed

Gladwell, Peter William; Badlan, Kathryn; Cramp, Fiona; Palmer, Shea

2015-11-01

There is no consensus regarding the effectiveness of transcutaneous electrical nerve stimulation (TENS) for management of chronic musculoskeletal pain or chronic low back pain. A recent review of previous trial methodology identified significant problems with low treatment fidelity. There is little information available to guide selection of patient-reported outcome measures appropriate for TENS evaluation. The purpose of this study was to explore the experiences of patients at a secondary care pain clinic who successfully used TENS to help manage chronic musculoskeletal pain. These key informants were selected because they had the potential to generate knowledge that could inform research design and clinical practice. A qualitative method using individual semistructured interviews with open questions was selected for its capacity to generate rich data. A mini focus group informed the development of a discussion guide for semistructured interviews with 9 patients (6 women, 3 men). Thematic analysis was used as the primary data analysis method, and this analysis was enhanced by a case-level analysis of the context and processes of TENS use of each individual. Data analysis indicated that distraction from pain and a reduction in the sensations associated with muscle tension or spasm should be considered as separate outcomes from pain relief. These direct benefits led to a wide range of indirect benefits dependent on patient decision making, including medication reduction, enhanced function, psychological benefits, and enhanced ability to rest. The findings indicate that evaluating TENS using a unidimensional pain scale is likely to overlook potential benefits. The complex pattern of TENS usage, as well as multiple direct and indirect outcomes, indicates that TENS could be considered as a complex intervention. © 2015 American Physical Therapy Association.

[Chronic fatigue syndrome treated with transcutaneous electrical acupoint stimulation: a randomized controlled trial].

PubMed

Li, Jinxia; Xie, Jingjun; Pan, Zhongqiang; Guo, Xiaoqing; Li, Ye; Fu, Ruiyang

2017-12-12

To evaluate the clinical therapeutic effects and safety of chronic fatigue syndrome treated with transcutaneous electrical acupoint stimulation (TEAS) on the conception vessel and the governor vessel. Eighty-nine patients of chronic fatigue syndrome were randomized into an observation group (46 cases) and a control group (43 cases). In the observation group, TEAS was applied at Dazhui (GV 14) and Mingmen (GV 4), Shenque (CV 8) and Guanyuan (CV 4) [the current intensity: (14±2) mA]. In the control group, the simulated TEAS was applied at the same acupoints as the observation group (the current intensity: 1 mA). The treatment was given for 30 min, once a day, 5 times a week and the treatment of 4 weeks was as 1 session in the two groups. One session of treatment was required. Before treatment and at the end of 1 session of treatment, the fatigue severity scale (FSS) was adopted to evaluate the fatigue symptoms and the somatic and psychological health report (SPHERE) was adopted to evaluate the potential symptoms and observe the safety of TEAS therapy. At the end of treatment, FSS score and SPHERE score in the control group were not different significantly as compared with those before treatment (both P >0.05). FSS score and SPHERE score in the observation group were reduced significantly as compared with those before treatment (both P <0.01). FSS score and SPHERE score in the observation group were reduced apparently as compared with those in the control group (both P <0.001). In the entire process of treatment with TEAS, no any adverse reaction occurred. TEAS on the conception vessel and the governor vessel relieves fatigue symptoms and the potential symptoms in the patients of chronic fatigue syndrome. It is a safe therapy.

Electrodes for high-definition transcutaneous DC stimulation for applications in drug delivery and electrotherapy, including tDCS.

PubMed

Minhas, Preet; Bansal, Varun; Patel, Jinal; Ho, Johnson S; Diaz, Julian; Datta, Abhishek; Bikson, Marom

2010-07-15

Transcutaneous electrical stimulation is applied in a range of biomedical applications including transcranial direct current stimulation (tDCS). tDCS is a non-invasive procedure where a weak direct current (<2 mA) is applied across the scalp to modulate brain function. High-definition tDCS (HD-tDCS) is a technique used to increase the spatial focality of tDCS by passing current across the scalp using <12 mm diameter electrodes. The purpose of this study was to design and optimize "high-definition" electrode-gel parameters for electrode durability, skin safety and subjective pain. Anode and cathode electrode potential, temperature, pH and subjective sensation over time were assessed during application of 2 mA direct current, for up to 22 min on agar gel or subject forearms. A selection of five types of solid-conductors (Ag pellet, Ag/AgCl pellet, rubber pellet, Ag/AgCl ring and Ag/AgCl disc) and seven conductive gels (Signa, Spectra, Tensive, Redux, BioGel, Lectron and CCNY-4) were investigated. The Ag/AgCl ring in combination with CCNY-4 gel resulted in the most favorable outcomes. Under anode stimulations, electrode potential and temperature rises were generally observed in all electrode-gel combinations except for Ag/AgCl ring and disc electrodes. pH remained constant for all solid-conductors except for both Ag and rubber pellet electrodes with Signa and CCNY-4 gels. Sensation ratings were independent of stimulation polarity. Ag/AgCl ring electrodes were found to be the most comfortable followed by Ag, rubber and Ag/AgCl pellet electrodes across all gels. Copyright 2010 Elsevier B.V. All rights reserved.

A novel implantable catheter system with transcutaneous port for intermittent convection-enhanced delivery of carboplatin for recurrent glioblastoma.

PubMed

Barua, Neil U; Hopkins, Kirsten; Woolley, Max; O'Sullivan, Stephen; Harrison, Rob; Edwards, Richard J; Bienemann, Alison S; Wyatt, Marcella J; Arshad, Azeem; Gill, Steven S

2016-01-01

Inadequate penetration of the blood-brain barrier (BBB) by systemically administered chemotherapies including carboplatin is implicated in their failure to improve prognosis for patients with glioblastoma. Convection-enhanced delivery (CED) of carboplatin has the potential to improve outcomes by facilitating bypass of the BBB. We report the first use of an implantable CED system incorporating a novel transcutaneous bone-anchored port (TBAP) for intermittent CED of carboplatin in a patient with recurrent glioblastoma. The CED catheter system was implanted using a robot-assisted surgical method. Catheter targeting accuracy was verified by performing intra-operative O-arm imaging. The TBAP was implanted using a skin-flap dermatome technique modeled on bone-anchored hearing aid surgery. Repeated infusions were performed by attaching a needle administration set to the TBAP. Drug distribution was monitored with serial real-time T2-weighted magnetic resonance imaging (MRI). All catheters were implanted to within 1.5 mm of their planned target. Intermittent infusions of carboplatin were performed on three consecutive days and repeated after one month without the need for further surgical intervention. Infused volumes of 27.9 ml per day were well tolerated, with the exception of a single seizure episode. Follow-up MRI at eight weeks demonstrated a significant reduction in the volume of tumor enhancement from 42.6 ml to 24.6 ml, and was associated with stability of the patient's clinical condition. Reduction in the volume of tumor enhancement indicates that intermittent CED of carboplatin has the potential to improve outcomes in glioblastoma. The novel technology described in this report make intermittent CED infusion regimes an achievable treatment strategy.

Electrodes for high-definition transcutaneous DC stimulation for applications in drug-delivery and electrotherapy, including tDCS

PubMed Central

Minhas, Preet; Bansal, Varun; Patel, Jinal; Ho, Johnson S.; Diaz, Julian; Datta, Abhishek; Bikson, Marom

2010-01-01

Transcutaneous electrical stimulation is applied in a range of biomedical applications including Transcranial Direct Current Stimulation (tDCS). tDCS is a non-invasive procedure where a weak direct current (<2 mA) is applied across the scalp to modulate brain function. High-Definition tDCS (HD-tDCS) is a technique used to increase the spatial focality of tDCS by passing current across the scalp using <12 mm diameter electrodes. The purpose of this study was to design and optimize “high-definition” electrode-gel parameters for electrode durability, skin safety, and subjective pain. Anode and cathode electrode potential, temperature, pH, and subjective sensation over time were assessed during application of 2 mA direct current, for up to 22 minutes on agar gel or subject forearms. A selection of 5 types of solid-conductors (Ag pellet, Ag/AgCl pellet, Rubber pellet, Ag/AgCl ring, and Ag/AgCl disc) and 7 conductive gels (Signa, Spectra, Tensive, Redux, BioGel, Lectron, and CCNY-4) were investigated. The Ag/AgCl ring in combination with CCNY-4 gel resulted in the most favorable outcomes. Under anode stimulations, electrode potential and temperature rises were generally observed in all electrode-gel combinations except for Ag/AgCl ring and disc electrodes. pH remained constant for all solid-conductors except for both Ag and Rubber pellet electrodes with Signa and CCNY-4 gels. Sensation ratings were independent of stimulation polarity. Ag/AgCl ring electrodes were found to be the most comfortable followed by Ag, Rubber, and Ag/AgCl pellet electrodes across all gels. PMID:20488204

Genetic algorithm optimization of transcutaneous energy transmission systems for implantable ventricular assist devices.

PubMed

Byron, Kelly; Bluvshtein, Vlad; Lucke, Lori

2013-01-01

Transcutaneous energy transmission systems (TETS) wirelessly transmit power through the skin. TETS is particularly desirable for ventricular assist devices (VAD), which currently require cables through the skin to power the implanted pump. Optimizing the inductive link of the TET system is a multi-parameter problem. Most current techniques to optimize the design simplify the problem by combining parameters leading to sub-optimal solutions. In this paper we present an optimization method using a genetic algorithm to handle a larger set of parameters, which leads to a more optimal design. Using this approach, we were able to increase efficiency while also reducing power variability in a prototype, compared to a traditional manual design method.

Transcutaneous measurement of glomerular filtration rate in conscious laboratory animals: state of the art and future perspectives

NASA Astrophysics Data System (ADS)

Friedemann, Jochen; Schock-Kusch, Daniel; Shulhevich, Yury

2017-02-01

Transcutaneous measurement of Glomerular Filtration Rate (tGFR) is now frequently used in preclinical in vivo animal studies. tGFR allows consecutive measurements on the same animal, including multiple measurements on a daily basis. A description of the measurement device and its many applications, along with examples from the recent literature will be given. We will highlight the fields of interest in which the system is used and give an overview about its performance versus endogenous and other exogenous methods of GFR measurement. A special focus will be put on the precision of tGFR compared to standard measurements employed in the research setting.

Preliminary audiologic and peri-operative outcomes of the Sophono™ transcutaneous bone conduction device: A systematic review.

PubMed

Bezdjian, Aren; Bruijnzeel, Hanneke; Daniel, Sam J; Grolman, Wilko; Thomeer, Hans G X M

2017-10-01

To delineate the auditory functional improvement and peri-operative outcomes of the Sophono™ transcutaneous bone conduction device. Eligible articles presenting patients implanted with the Sophono™ were identified through a comprehensive search of PubMed and Embase electronic databases. All relevant articles were reviewed to justify inclusion independently by 2 authors. Studies that successfully passed critical appraisal for directness of evidence and risk of bias were included. From a total of 125 articles, 8 studies encompassing 86 patients using 99 implants were selected. Most patients (79.1%) were children. Ear atresia (67.5%) was the most frequently reported indication for Sophono™ implantation. Overall pure tone average auditory improvement was 31.10 (±8.29) decibel. During a mean follow-up time of 12.48 months, 25 patients (29%) presented with post-operative complications from which 3 were deemed as serious implant-related adverse events (3.5%). The Sophono™ transcutaneous bone conduction device shows promising functional improvement, no intra-operative complications and minor post-operative skin related complications. If suitable, the device could be a proposed solution for the rehabilitation of hearing in children meeting eligibility criteria. A wearing schedule must be implemented in order to reduce magnet-related skin complications. Copyright © 2017 Elsevier B.V. All rights reserved.

The Role of Transcutaneous Electrical Nerve Stimulation in the Management of Temporomandibular Joint Disorder.

PubMed

Awan, Kamran Habib; Patil, Shankargouda

2015-12-01

Temporomandibular joint disorders (TMD) constitutes of a group of diseases that functionally affect the masticatory system, including the muscles of mastication and temporomandibular joint (TMJ). A number of etiologies with specific treatment have been identified, including the transcutaneous electrical nerve stimulation (TENS). The current paper presents a literature review on the use of TENS in the management of TMD patients. Temporomandibular joint disorder is very common disorder with approximately 75% of people showing some signs, while more than quarter (33%) having at least one symptom. An attempt to treat the pain should be made whenever possible. However, in cases with no defined etiology, starting with less intrusive and reversible techniques is prescribed. Transcutaneous electrical nerve stimulation is one such treatment modality, i.e. useful in the management of TMD. It comprises of controlled exposure of electrical current to the surface of skin, causing hyperactive muscles relaxation and decrease pain. Although the value of TENS to manage chronic pain in TMD patients is still controversial, its role in utilization for masticatory muscle pain is significant. However, an accurate diagnosis is essential to minimize its insufficient use. Well-controlled randomized trials are needed to determine the utilization of TENS in the management of TMD patients.

Effects of baby massage on neonatal jaundice in healthy Iranian infants: A pilot study.

PubMed

Dalili, Hosein; Sheikhi, Sanaz; Shariat, Mamak; Haghnazarian, Edith

2016-02-01

To evaluate the effects of baby massage on transcutaneous bilirubin levels and stool frequency of healthy term newborns. This Pilot study was conducted on 50 healthy newborns in Valiasr Hospital of IKHC. The infants were randomly allocated to two treatment (massage) and control group. The massage group received massage therapy (according to Touch Therapy) for four days from the first day postnatal while the control group received routine care. Main variable studied were transcutaneous bilirubin level (TCB) and stool frequency which were compared in two groups. There were 50 newborns in the study 25 in each group (50%). There was a significant difference in the TCB levels between two groups (p=0.000) with those in the massage group having lower bilirubin levels. As for the stool frequency there was a significant difference in two groups on the first day showing more defecation in the control group (p=0.042) which on the consequent days was not significant and the frequencies were almost similar. Massage group had a lower transcutaneous billirubin levels compared to the control group, thus, these pilot results indicate that massaging the newborns can be accompanied by a lower bilirubin level in the healthy term newborn. Copyright © 2015 Elsevier Inc. All rights reserved.

Influence of different frequencies of transcutaneous electrical nerve stimulation on the threshold and pain intensity in young subjects

PubMed Central

Gomes, Adriana de Oliveira; Silvestre, Ana Caroline; da Silva, Cristina Ferreira; Gomes, Mariany Ribeiro; Bonfleur, Maria Lúcia; Bertolini, Gladson Ricardo Flor

2014-01-01

Objective To investigate the effects of different transcutaneous electrical nerve stimulation frequencies in nociception front of a pressure pain threshold and cold in healthy individuals. Methods Twenty healthy subjects were divided into four groups, all of which have gone through all forms of electrical stimulation at different weeks. Assessments were pre and post-therapy, 20 and 60 minutes after stimulation. To evaluate the pressure pain threshold, an algometer was used with one tapered tip, pressing the hypothenar region until voluntary report the word “pain”. Cold pain intensity was assessed by immersion in water at 5°C for 30 seconds; at the end, the subject was asked to quantify the pain intensity on a Visual Analog Scale for Pain. For electrical stimulation, two electrodes were used near the elbow, for 20 minutes, with an intensity strong, but not painful. The frequency was in accordance with the group: 0Hz (placebo); 7Hz; 100Hz; and 255Hz. Results Both for the assessment of pressure pain threshold as the cold pain intensity, there was no significant difference (p>0.05). Conclusion We conclude that the use of transcutaneous electrical nerve stimulation on dermatomes C6 to C8 produced no significant change in pressure pain threshold or cold discomfort. PMID:25295453

Can the human lumbar posterior columns be stimulated by transcutaneous spinal cord stimulation? A modeling study

PubMed Central

Danner, Simon M.; Hofstoetter, Ursula S.; Ladenbauer, Josef; Rattay, Frank; Minassian, Karen

2014-01-01

Stimulation of different spinal cord segments in humans is a widely developed clinical practice for modification of pain, altered sensation and movement. The human lumbar cord has become a target for modification of motor control by epidural and more recently by transcutaneous spinal cord stimulation. Posterior columns of the lumbar spinal cord represent a vertical system of axons and when activated can add other inputs to the motor control of the spinal cord than stimulated posterior roots. We used a detailed three-dimensional volume conductor model of the torso and the McIntyre-Richard-Grill axon model to calculate the thresholds of axons within the posterior columns in response to transcutaneous lumbar spinal cord stimulation. Superficially located large diameter posterior column fibers with multiple collaterals have a threshold of 45.4 V, three times higher than posterior root fibers (14.1 V). With the stimulation strength needed to activate posterior column axons, posterior root fibers of large and small diameters as well as anterior root fibers are co-activated. The reported results inform on these threshold differences, when stimulation is applied to the posterior structures of the lumbar cord at intensities above the threshold of large-diameter posterior root fibers. PMID:21401670

Efficacy and Safety of Transthoracic Echocardiography Alone in Transcatheter Closure of Secundum-Type Atrial Septal Defects in Adults.

PubMed

Ding, Cheng; Chang, Jia-Kan; Lin, Chang-Chyi; Wu, Yong-Jian; Hsieh, Kai-Sheng

2016-04-01

On-site transthoracic echocardiography (TTE) to guide the transcutaneous closure of secundum-type atrial septal defects (ASDs) in the catheterization laboratory remains unclear, especially in adults. Between 2005 and 2012, a total of 82 adults underwent transcutaneous closure of ASDs. The initial 15 cases underwent the procedure with both on-site transesophageal echocardiography (TEE) and TTE monitoring. Since January 2008, a total of 67 patients underwent on-site TTE alone to guide the procedure. Among the 82 adult patients who underwent a transcutaneous closure of the secundum-type ASD procedure, all had successful closure of the defects, and no periprocedural adverse complications occurred. No statistical significance was observed in the successful complete shunt closure rate between the TEE plus TTE and TTE groups during sequential follow-up (postprocedure 24 hour [87% vs. 92%],1 month [93% vs. 95%], 3 month [93% vs. 97%], and 12 month [93% vs. 97%], P > 0.05, respectively) nor was a significant difference observed between the two groups, including decreased right ventricular dimension (29.5 ± 3.3 vs. 32.0 ± 4.9 mm, 26.5 ± 3.0 vs. 28.7 ± 4.6 mm, 26.2 ± 3.1 vs. 28.2 ± 4.8 mm, and 25.6 ± 2.8 vs. 27.7 ± 4.7 mm, P > 0.05, respectively) or increased left ventricular end-diastolic dimension (41.1 ± 2.0 vs. 42.6 ± 3.0 mm, 44.3 ± 2.7 vs. 45.5 ± 3.1 mm, 44.2 ± 2.8 vs. 45.4 ± 3.1 mm, 44.9 ± 2.7 vs. 45.8 ± 2.6 mm, P > 0.05, respectively) before the procedure, and at the 3-, 6-, and 12-month follow-up evaluations. This study showed that TTE guidance alone may be considered efficacious and safe as TEE during a transcutaneous ASD occlusion procedure in select adults. © 2015, Wiley Periodicals, Inc.

CNS BOLD fMRI effects of sham-controlled transcutaneous electrical nerve stimulation in the left outer auditory canal - a pilot study.

PubMed

Kraus, Thomas; Kiess, Olga; Hösl, Katharina; Terekhin, Pavel; Kornhuber, Johannes; Forster, Clemens

2013-09-01

It has recently been shown that electrical stimulation of sensory afferents within the outer auditory canal may facilitate a transcutaneous form of central nervous system stimulation. Functional magnetic resonance imaging (fMRI) blood oxygenation level dependent (BOLD) effects in limbic and temporal structures have been detected in two independent studies. In the present study, we investigated BOLD fMRI effects in response to transcutaneous electrical stimulation of two different zones in the left outer auditory canal. It is hypothesized that different central nervous system (CNS) activation patterns might help to localize and specifically stimulate auricular cutaneous vagal afferents. 16 healthy subjects aged between 20 and 37 years were divided into two groups. 8 subjects were stimulated in the anterior wall, the other 8 persons received transcutaneous vagus nervous stimulation (tVNS) at the posterior side of their left outer auditory canal. For sham control, both groups were also stimulated in an alternating manner on their corresponding ear lobe, which is generally known to be free of cutaneous vagal innervation. Functional MR data from the cortex and brain stem level were collected and a group analysis was performed. In most cortical areas, BOLD changes were in the opposite direction when comparing anterior vs. posterior stimulation of the left auditory canal. The only exception was in the insular cortex, where both stimulation types evoked positive BOLD changes. Prominent decreases of the BOLD signals were detected in the parahippocampal gyrus, posterior cingulate cortex and right thalamus (pulvinar) following anterior stimulation. In subcortical areas at brain stem level, a stronger BOLD decrease as compared with sham stimulation was found in the locus coeruleus and the solitary tract only during stimulation of the anterior part of the auditory canal. The results of the study are in line with previous fMRI studies showing robust BOLD signal decreases in limbic structures and the brain stem during electrical stimulation of the left anterior auditory canal. BOLD signal decreases in the area of the nuclei of the vagus nerve may indicate an effective stimulation of vagal afferences. In contrast, stimulation at the posterior wall seems to lead to unspecific changes of the BOLD signal within the solitary tract, which is a key relay station of vagal neurotransmission. The results of the study show promise for a specific novel method of cranial nerve stimulation and provide a basis for further developments and applications of non-invasive transcutaneous vagus stimulation in psychiatric patients. Copyright © 2013 Elsevier Inc. All rights reserved.

The effects of transcutaneous electrical nerve stimulation on joint position sense in patients with knee joint osteoarthritis.

PubMed

Shirazi, Zahra Rojhani; Shafaee, Razieh; Abbasi, Leila

2014-10-01

To study the effects of transcutaneous electrical nerve stimulation (TENS) on joint position sense (JPS) in knee osteoarthritis (OA) subjects. Thirty subjects with knee OA (40-60 years old) using non-random sampling participated in this study. In order to evaluate the absolute error of repositioning of the knee joint, Qualysis Track Manager system was used and sensory electrical stimulation was applied through the TENS device. The mean errors in repositioning of the joint, in two position of the knee joint with 20 and 60 degree angle, after applying the TENS was significantly decreased (p < 0.05). Application of TENS in subjects with knee OA could improve JPS in these subjects.

Transcutaneous analyte measuring method (TAMM): a reflective, noninvasive, near-infrared blood chemistry analyzer

NASA Astrophysics Data System (ADS)

Schlager, Kenneth J.; Ruchti, Timothy L.

1995-04-01

TAMM for Transcutaneous Analyte Measuring Method is a near infrared spectroscopic technique for the noninvasive measurement of human blood chemistry. A near infrared indium gallium arsenide (InGaAs) photodiode array spectrometer has been developed and tested on over 1,000 patients as a part of an SBIR program sponsored by the Naval Medical Research and Development Command. Nine (9) blood analytes have been measured and evaluated during pre-clinical testing: sodium, chloride, calcium, potassium, bicarbonate, BUN, glucose, hematocrit and hemoglobin. A reflective rather than a transmissive invasive approach to measurement has been taken to avoid variations resulting from skin color and sensor positioning. The current status of the instrumentation, neural network pattern recognition algorithms and test results will be discussed.

Application of optical coherence tomography for assessment of transcutaneous vaccine delivery

NASA Astrophysics Data System (ADS)

Kamali, T.; Rattanapak, T.; Hook, S.; Meglinski, I.

2012-03-01

Immunization is one of the most efficient and cost-effective means for the prevention of diseases, but most vaccines have to be administered invasively. A novel strategy of inducing an immune response is topical application of vaccines to intact skin. Apart from being a non-invasive route of drug delivery, skin delivery also offers an advantageous mode of immunization due to the ability of skin immune cells to present antigens to the immune system. Topical vaccine penetration through the outermost layers of skin is based on the percutaneous diffusion of lipid-based nano-particles. In the current study we investigate the applicability of Optical Coherence Tomography for monitoring transcutaneous delivery of a peptide vaccine into the skin in vivo.

Subcuticular Suture Technique: Alternative to Frost Suture to Prevent Ectropion After Transcutaneous Incision of Lower Eyelid.

PubMed

Kudva, Adarsh; Kamath, Abhay; Cariappa, K M; Gadicherla, Srikanth; Dhara, B Vasantha

2017-12-01

An ectropion is a complication that can arise from reconstruction in the infraorbital region. Often, this complication occurs despite proper positioning of the lower lid at the time of closure. Various transcutaneous approaches to orbit skeleton have investigated in view of complication arising from them. A subtarsal approach with a postoperative Frost suture gives an advantage to reduce the occurrence of ectropion especially after treatment of orbital floor fractures. This case describes a method of subcuticular suturing technique for subtarsal incision of lower lid which can be used to support the lid during healing period, thus decreasing the rate of ectropion. The technique described here is an alterative method for frost suturing with certain advantages.

Cyanotic heart disease

MedlinePlus

... by checking it through the skin with a pulse oximeter Complete blood count (CBC) ECG (electrocardiogram) Looking at ... from the groin ( cardiac catheterization ) Transcutaneous oxygen monitor (pulse oximeter) Echo-Doppler

EMG activity of finger flexor muscles and grip force following low-dose transcutaneous electrical nerve stimulation in healthy adult subjects.

PubMed

Kafri, Michal; Zaltsberg, Nir; Dickstein, Ruth

2015-01-01

Somatosensory stimulation modulates cortical and corticospinal excitability and consequently affects motor output. Therefore, low-amplitude transcutaneous electrical nerve stimulation (TENS) has the potential to elicit favorable motor responses. The purpose of the two presented pilot studies was to shed light on TENS parameters that are relevant for the enhancement of two desirable motor outcomes, namely, electromyographic (EMG) activity and contraction strength of the finger flexors and wrist muscles. In 5 and 10 healthy young adults (in Study I and Study II, respectively) TENS was delivered to the volar aspect of the forearm. We manipulated TENS frequency (150 Hz vs. 5 Hz), length of application (10, 20, and 60 min), and side of application (unilateral, right forearm vs. bilateral forearms). EMG amplitude and grip force were measured before (Pre), immediately after (Post), and following 15 min of no stimulation (Study I only). The results indicated that low-frequency bursts of TENS applied to the skin overlying the finger flexor muscles enhance the EMG activity of the finger flexors and grip force. The increase in EMG activity of the flexor muscles was observed after 20 min of stimulation, while grip force was increased only after 1 h. The effects of uni- and bilateral TENS were comparable. These observations allude to a modulatory effect of TENS on the tested motor responses; however, unequivocal conclusions of the findings are hampered by individual differences that affect motor outcomes, such as in level of attention.

Effect of skin barrier disruption on immune responses to topically applied cross-reacting material, CRM(197), of diphtheria toxin.

PubMed

Godefroy, S; Peyre, M; Garcia, N; Muller, S; Sesardic, D; Partidos, C D

2005-08-01

The high accessibility of the skin and the presence of immunocompetent cells in the epidermis makes this surface an attractive route for needle-free administration of vaccines. However, the lining of the skin by the stratum corneum is a major obstacle to vaccine delivery. In this study we examined the effect of skin barrier disruption on the immune responses to the cross-reacting material CRM(197), a nontoxic mutant of diphtheria toxin (DTx) that is considered as a vaccine candidate. Application of CRM(197), together with cholera toxin (CT), onto the tape-stripped skin of mice elicited antibody responses that had anti-DTx neutralizing activity. Vaccine delivery onto mildly ablated skin or intact skin did not elicit any detectable anti-CRM(197) antibodies. Mice immunized with CRM(197) alone onto the tape-stripped skin mounted a vigorous antigen-specific proliferative response. In contrast, the induction of cellular immunity after CRM(197) deposition onto mildly ablated or intact skin was adjuvant dependent. Furthermore, epidermal cells were activated and underwent apoptosis that was more pronounced when the stratum corneum was removed by tape stripping. Overall, these findings highlight the potential for transcutaneous delivery of CRM(197) and establish a correlation between the degree of barrier disruption and levels of antigen-specific immune responses. Moreover, these results provide the first evidence that the development of a transcutaneous immunization strategy for diphtheria, based on simple and practical methods to disrupt the skin barrier, is feasible.

Nanoparticles for transcutaneous vaccination

PubMed Central

Hansen, Steffi; Lehr, Claus‐Michael

2012-01-01

Summary The living epidermis and dermis are rich in antigen presenting cells (APCs). Their activation can elicit a strong humoral and cellular immune response as well as mucosal immunity. Therefore, the skin is a very attractive site for vaccination, and an intradermal application of antigen may be much more effective than a subcutaneous or intramuscular injection. However, the stratum corneum (SC) is a most effective barrier against the invasion of topically applied vaccines. Products which have reached the stage of clinical testing, avoid this problem by injecting the nano‐vaccine intradermally or by employing a barrier disrupting method and applying the vaccine to a relatively large skin area. Needle‐free vaccination is desirable from a number of aspects: ease of application, improved patient acceptance and less risk of infection among them. Nanocarriers can be designed in a way that they can overcome the SC. Also incorporation into nanocarriers protects instable antigen from degradation, improves uptake and processing by APCs, and facilitates endosomal escape and nuclear delivery of DNA vaccines. In addition, sustained release systems may build a depot in the tissue gradually releasing antigen which may avoid booster doses. Therefore, nanoformulations of vaccines for transcutaneous immunization are currently a very dynamic field of research. Among the huge variety of nanocarrier systems that are investigated hopes lie on ultra‐flexible liposomes, superfine rigid nanoparticles and nanocarriers, which are taken up by hair follicles. The potential and pitfalls associated with these three classes of carriers will be discussed. PMID:21854553

A Preliminary Study of a Transdermal Radiofrequency Device for Body Slimming.

PubMed

Key, Douglas J

2015-11-01

The use and potential of radiofrequency energy for tissue contracture and body contouring has been established in the literature. Maximum reduction of laxity can be achieved by simultaneously tightening surface tissue and reducing unwanted fat below by the transdermal application of heat to reach and maintain tissue temperature targets within a well-defined range, inducing collagen remodeling in skin as well as apoptosis of fat cells and creating an overall slimming effect. A novel device utilizes transcutaneous monopolar RF for body slimming in this manner, employing a thermistor feedback control mechanism to safely manage energy delivery and tissue temperature. Subjects (n=14) presenting with abdominal laxity were treated up to four times using the transcutaneous monopolar RF device at one or two zones in the abdominal region (at operator's discretion). Non-expert blinded graders rated correction on an arbitrary scale (0=no laxity, 4=maximum laxity) after choosing the order of the before-and-after photo sets. A patient satisfaction survey was also administered. The two graders correctly ordered 10 of 14 photo sets in agreement. Average rated improvement was 0.75 and 0.80 for graders 1 and 2, respectively. Patient survey results revealed average perceived tightening of 2.14 points on a 0 to 4 scale (0=lowest tightening result, 4=highest tightening), and 8 of 14 subjects would recommend treatment to others. Transdermal monopolar RF is a safe and effective modality for non-invasive body slimming.

On the origin of the electrostatic potential difference at a liquid-vacuum interface.

PubMed

Harder, Edward; Roux, Benoît

2008-12-21

The microscopic origin of the interface potential calculated from computer simulations is elucidated by considering a simple model of molecules near an interface. The model posits that molecules are isotropically oriented and their charge density is Gaussian distributed. Molecules that have a charge density that is more negative toward their interior tend to give rise to a negative interface potential relative to the gaseous phase, while charge densities more positive toward their interior give rise to a positive interface potential. The interface potential for the model is compared to the interface potential computed from molecular dynamics simulations of the nonpolar vacuum-methane system and the polar vacuum-water interface system. The computed vacuum-methane interface potential from a molecular dynamics simulation (-220 mV) is captured with quantitative precision by the model. For the vacuum-water interface system, the model predicts a potential of -400 mV compared to -510 mV, calculated from a molecular dynamics simulation. The physical implications of this isotropic contribution to the interface potential is examined using the example of ion solvation in liquid methane.

Non-invasive, epicutaneous immunisation with toxoid in deformable vesicles protects mice against tetanus, chiefly owing to a Th2 response.

PubMed

Chopra, Amla; Cevc, Gregor

2014-06-02

A non-invasive, intra/transcutaneous immunisation of mice with a suitable combination of tetanus toxoid, ultradeformable vesicle (Transfersome®) carrier, and monophosphoryl lipid A adjuvant targets immuno-competent cells in a body and can protect 100% of the tested mice against an otherwise lethal (50×LD50) parenteral tetanus toxin challenge. The late immune response to the epicutaneously applied tetanus toxoid in such vesicles consists chiefly of circulating IgG1 and IgG2b antibody isotypes, indicative of a specific Th2 cellular response bias. Immunisations by subcutaneous injections moreover protect 100% of mice against a similar, otherwise lethal, dose of tetanus toxin. However, the immune response to transcutaneous and invasive immunisation differs. The latter elicits mainly IgG1 and IgG2b as well as IgG2a antibody isotypes, indicative of a mixed Th1/Th2 response. The cytokine response of the intra/transcutaneously and subcutaneously immunised mice reflects the difference in the organ-specific manner. IFN-γ concentration is appreciably increased in the draining lymph nodes and IL-10 in spleen. Since tetanus is a neutral antigen, both the Th1-specific IFN-γ and the Th-2 specific-IL-10 are observable. Copyright © 2014 Elsevier B.V. All rights reserved.

Transcutaneous electrical nerve stimulation effect on postoperative complications.

PubMed

Sezen, Celal Bugra; Akboga, Suleyman Anil; Celik, Ali; Kalafat, Cem Emrah; Tastepe, Abdullah Irfan

2017-05-01

Objectives Transcutaneous electrical nerve stimulation has been used to control post-thoracotomy pain, with conflicting results. We aimed to assess its efficacy on post-thoracotomy pain and early complications. Methods Between January 2012 and December 2014, 87 patients underwent a standard posterolateral thoracotomy and were randomized in 2 groups: group T was 43 patients who had transcutaneous electrical nerve stimulation and group C was 44 patients who had placebo stimulation with an inoperative device. Pain score was measured using a visual analogue scale ranging from 0 to 10. The frequency of the device was set at 100 Hz and pulse width at 100 ms. Results There were no statistically significant differences in the demographic characteristics of the 2 groups, and there was no difference in the duration of hospitalization (4.74 ± 1.6 vs. 5.23 ± 1.5 days; p = 0.06). Postoperative pain scores of the two groups showed that on postoperative day 0, 1, and 2, the mean pain scores of group T were significantly lower ( p = 0.001, p < 0.001, and p = 0.003). There were no significant differences in early complications or surgical technique. Conclusion We concluded that electrical stimulation is a safe and effective adjunctive therapy for acute post-thoracotomy pain control. However, it does not affect the duration of hospitalization or early pulmonary complications.

Relationship between transcutaneous bilirubin and circulating unbound bilirubin in jaundiced neonates.

PubMed

Letamendia-Richard, Emmanuelle; Ammar, Rafik Ben; Tridente, Ascanio; De Luca, Daniele

2016-12-01

Transcutaneous bilirubin (TcB) consists of the skin-deposited bilirubin. Free bilirubin represents the protein-unbound bilirubin (UB) that is able to pass into the tissues. We aimed to describe the relationship UB-TcB and study the passage of UB into the skin. We prospectively enrolled 194 neonates and we measured TcB, UB, serum bilirubin and albumin. Multiple sites TcB measurement was performed, bilirubin-albumin equilibrium constant and plasma bilirubin avidity (PBA) were calculated. TcB has a similar correlation with UB and TSB. There is a quadratic relationship between UB and TcB (R 2 =0.48; p<0.001), remaining significant (β for UB 2 =-0.8; p<0.001. β for UB=1.1; p<0.001) after adjustment for gestational age, birth weight, postnatal age and albumin (Adj-R 2 =0.72). UB contributes to the skin bilirubin deposition, as there are significant correlations between albumin and TcB (r=-0.202; p=0.01) and between PBA and ΔTcB (r=0.323; p=0.017). TcB assay does not seem to directly replace UB measurement. However, TcB and UB are linked by a quadratic relationship: UB contributes to the skin bilirubin deposition but it is not the only bilirubin species measured by transcutaneous bilirubinometry. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A Prototype Therapy System for Transcutaneous Application of Boiling Histotripsy.

PubMed

Maxwell, Adam D; Yuldashev, Petr V; Kreider, Wayne; Khokhlova, Tatiana D; Schade, George R; Hall, Timothy L; Sapozhnikov, Oleg A; Bailey, Michael R; Khokhlova, Vera A

2017-10-01

Boiling histotripsy (BH) is a method of focused ultrasound surgery that noninvasively applies millisecond-length pulses with high-amplitude shock fronts to generate liquefied lesions in tissue. Such a technique requires unique outputs compared to a focused ultrasound thermal therapy apparatus, particularly to achieve high in situ pressure levels through intervening tissue. This paper describes the design and characterization of a system capable of producing the necessary pressure to transcutaneously administer BH therapy through clinically relevant overlying tissue paths using pulses with duration up to 10 ms. A high-voltage electronic pulser was constructed to drive a 1-MHz focused ultrasound transducer to produce shock waves with amplitude capable of generating boiling within the pulse duration in tissue. The system output was characterized by numerical modeling with the 3-D Westervelt equation using boundary conditions established by acoustic holography measurements of the source field. Such simulations were found to be in agreement with directly measured focal waveforms. An existing derating method for nonlinear therapeutic fields was used to estimate in situ pressure levels at different tissue depths. The system was tested in ex vivo bovine liver samples to create BH lesions at depths up to 7 cm. Lesions were also created through excised porcine body wall (skin, adipose, and muscle) with 3-5 cm thickness. These results indicate that the system is capable of producing the necessary output for transcutaneous ablation with BH.

Basic study of a transcutaneous information transmission system using intra-body communication.

PubMed

Okamoto, Eiji; Sato, Yusuke; Seino, Kazuyuki; Kiyono, Takashi; Kato, Yoshikuni; Mitamura, Yoshinori

2010-07-01

The transcutaneous communication system (TCS) is one of the key technologies for monitoring and controling artificial hearts and other artificial organs in the body. In this study, we have developed a new TCS that uses the human body as a conductive medium. Having no energy conversion from electric currents into electromagnetic waves and light provides energy-saving data transmission with a simple electrical circuit. Each unit of the TCS mainly consists of two electrodes, an amplitude shift keying (ASK) modulator and an ASK demodulator (carrier frequency: 4 and 10 MHz). A resonant frequency of an L-C tank circuit including the capacitance component of the body is tuned into each carrier frequency in order to apply the data current effectively into the body. Performance of the TCS was evaluated by a communication test on the surface of a human body. The TCS was able to transmit 3,315 bytes of data bi-directionally at a transmission rate of 115 kbps from a left wrist to a right forearm, to an abdomen and to a left calf without communication error. The power consumption of each TCS unit was 125 mW with an ASK modulated current of 7 mA (RMS). While further study is required to secure its safety, the TCS promises to be a next-generation transcutaneous communication device.

Improvement of conventional transcutaneous bilirubinometry results in term newborn infants.

PubMed

Felc, Zlata

2005-05-01

This prospective study was performed to determine a way to improve conventional transcutaneous bilirubinometry results in healthy term newborn infants. In 118 infants during phototherapy (group A), and in 118 infants without phototherapy (group B), bilirubin determinations were done in duplicate using the Minolta AirShields Jaundice Meter type 101 (transcutaneous bilirubin index [TcB]), and the diazometric method on the Hitachi 717 Automated Analyzer (total reacting serum bilirubin [SeB]). In 112 infants (group C), bilirubin determinations were done in triplicate, using simple direct-reading photometry on the Moltronic Bilirubinometer (direct serum bilirubin [BiB]). A close correlation between TcB and SeB values was observed in group A ( r = 0.69; p < 0.001) and in group B ( r = 0.59; p < 0.001). The 95% confidence intervals of TcB readings corresponding to SeB were +/- 80.7 micromol/L in group A and +/- 76.9 micromol/L in group B, respectively. In group C, using a correctly calibrated BiB with adult sera containing bilirubin concentration in the range 271 to 344 micromol/L, the 95% confidence intervals of parallel TcB and BiB readings corresponding to SeB were +/- 28 micromol/L. Parallel determinations of the TcB and the BiB in healthy term newborn infants give results almost identical to those of bilirubin determination by the laboratory method.

Does transcutaneous nerve stimulation have effect on sympathetic skin response?

PubMed

Okuyucu, E Esra; Turhanoğlu, Ayşe Dicle; Guntel, Murat; Yılmazer, Serkan; Savaş, Nazan; Mansuroğlu, Ayhan

2018-01-01

This study examined the effects of transcutaneous electrical nerve stimulation (TENS) on the sympathetic nerve system by sympathetic skin response test. Fifty-five healthy volunteers received either: (i) 30minutes TENS (25 participants) (ii) 30minutes sham TENS (30 participants) and SSR test was performed pre- and post-TENS. The mean values of latency and peak-to-peak amplitude of five consecutive SSRs were calculated. A significant amplitude difference was found between TENS and sham TENS group both in right and left hand (p=0.04, p=0.01, respectively). However there was no significant latancy difference between two groups (p>0.05 ). TENS has an inhibitory effect on elicited SNS responses when compared with sham TENS control group. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Development of transcutaneous jaundice predictor for the neonates].

PubMed

Zhu, Pengzhi; Yuan, Hengxin; Tan, Zhifeng; Zhu, Guoping; Yi, Yongju

2011-06-01

Neonatal jaundice is a common neonatal disease. Severe jaundices lead to kernicterus that affects intellectual development of infants or even causes death. Timely and early prediction is vital to the treatment and prevention. This paper presents a jaundice predictor, which uses C8051F020 as the core of single-chip microcomputer (SCM) system with prediction algorithms proven by a large number of clinical trials. The jaundice predictor can reduce the incidence rate of jaundice, alleviate the condition of infants with jaundice, improve the quality of perinatal, with predicting pathologic neonatal jaundice effectively and calling attention to the prophylactic treatment. In addition, compared with the existing transcutaneous jaundice meters, the new predictor has a smaller size, a lighter weight, more user-friendly, and easier to use by hand-holding.

The newborn oxygram: automated processing of transcutaneous oxygen data.

PubMed

Horbar, J D; Clark, J T; Lucey, J F

1980-12-01

Hypoxemic and hyperoxemic episodes are common in newborns with respiratory disorders. We have developed a microprocessor-based data system for use with transcutaneous oxygen (TcPO2) monitors in an attempt to quantitate these episodes. The amount of time spent by an infant in each of ten preset TcPO2 ranges can be automatically recorded. These data are referred to as the oxygram. Fourteen newborn infants were monitored for a total of 552 hours using this system. They spent a mean of 2.96% of the time with a TcPO2 less than or equal to 40 torr and 0.26% of the time with a TcPO2 greater than 100 torr. Representative oxygrams are presented. Clinical and research applications of the data system are discussed.

Concept Developed for an Implanted Stimulated Muscle-Powered Piezoelectric Generator

NASA Technical Reports Server (NTRS)

Lewandowski, Beth; Kilgore, Kevin; Ercegovic, David; Gustafson, Kenneth

2005-01-01

Implanted electronic devices are typically powered by batteries or transcutaneous power transmission. Batteries must be replaced or recharged, and transcutaneous power sources burden the patient or subject with external equipment prone to failure. A completely self-sustaining implanted power source would alleviate these limitations. Skeletal muscle provides an available autologous power source containing native chemical energy that produces power in excess of the requirements for muscle activation by motor nerve stimulation. A concept has been developed to convert stimulated skeletal muscle power into electrical energy (see the preceding illustration). We propose to connect a piezoelectric generator between a muscle tendon and bone. Electrically stimulated muscle contractions would exert force on the piezoelectric generator, charging a storage circuit that would be used to power the stimulator and other devices.

Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain

PubMed Central

Gozani, Shai N

2016-01-01

Objective The objective of this study was to determine if fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS) is effective in treating chronic low back and lower extremity pain. Background Transcutaneous electrical nerve stimulation is widely used for treatment of chronic pain. General-purpose transcutaneous electrical nerve stimulation devices are designed for stimulation anywhere on the body and often cannot be used while the user is active or sleeping. FS-TENS devices are designed for placement at a pre-determined location, which enables development of a wearable device for use over extended time periods. Methods Study participants with chronic low back and/or lower extremity pain self-administered an FS-TENS device for 60 days. Baseline, 30-, and 60-day follow-up data were obtained through an online questionnaire. The primary outcome measure was the patient global impression of change. Pain intensity and interference were assessed using the Brief Pain Inventory. Changes in use of concomitant pain medications were evaluated with a single-item global self-rating. Results One hundred and thirty participants were enrolled, with 88 completing the 60-day follow-up questionnaire. Most participants (73.9%) were 50 years of age or older. At baseline, low back pain was identified by 85.3%, lower extremity pain by 71.6%, and upper extremity pain by 62.5%. Participants reported widespread pain, at baseline, with a mean of 3.4 (standard deviation 1.1) pain sites. At the 60-day follow-up, 80.7% of participants reported that their chronic pain had improved and they were classified as responders. Baseline characteristics did not differentiate non-responders from responders. There were numerical trends toward reduced pain interference with walking ability and sleep, and greater pain relief in responders. There was a large difference in use of concomitant pain medications, with 80.3% of responders reporting a reduction compared to 11.8% of non-responders. Conclusion FS-TENS is a safe and effective option for treating chronic low back and lower extremity pain. These results motivate the use of FS-TENS in development of wearable analgesic devices. PMID:27418854

Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain.

PubMed

Gozani, Shai N

2016-01-01

The objective of this study was to determine if fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS) is effective in treating chronic low back and lower extremity pain. Transcutaneous electrical nerve stimulation is widely used for treatment of chronic pain. General-purpose transcutaneous electrical nerve stimulation devices are designed for stimulation anywhere on the body and often cannot be used while the user is active or sleeping. FS-TENS devices are designed for placement at a pre-determined location, which enables development of a wearable device for use over extended time periods. Study participants with chronic low back and/or lower extremity pain self-administered an FS-TENS device for 60 days. Baseline, 30-, and 60-day follow-up data were obtained through an online questionnaire. The primary outcome measure was the patient global impression of change. Pain intensity and interference were assessed using the Brief Pain Inventory. Changes in use of concomitant pain medications were evaluated with a single-item global self-rating. One hundred and thirty participants were enrolled, with 88 completing the 60-day follow-up questionnaire. Most participants (73.9%) were 50 years of age or older. At baseline, low back pain was identified by 85.3%, lower extremity pain by 71.6%, and upper extremity pain by 62.5%. Participants reported widespread pain, at baseline, with a mean of 3.4 (standard deviation 1.1) pain sites. At the 60-day follow-up, 80.7% of participants reported that their chronic pain had improved and they were classified as responders. Baseline characteristics did not differentiate non-responders from responders. There were numerical trends toward reduced pain interference with walking ability and sleep, and greater pain relief in responders. There was a large difference in use of concomitant pain medications, with 80.3% of responders reporting a reduction compared to 11.8% of non-responders. FS-TENS is a safe and effective option for treating chronic low back and lower extremity pain. These results motivate the use of FS-TENS in development of wearable analgesic devices.

Non-invasive ventilation: evaluation of CO2 washout by intentional leaking in three recent oronasal masks. A pilot study.

PubMed

Medrinal, C; Prieur, G; Contal, O; Villiot-Danger, E; Doyle, C; Reychler, G; Quieffin, J

2015-05-01

Many types of interfaces with intentional leaks exist for Non Invasive Ventilation. The purpose of intentional leaks is to remove CO2 from the interface, however the calibration does not allow a sufficiently large flow and rebreathing of CO2 can occur. The aim of this study was to compare the CO2 rinsing capacities of three new generation oronasal masks with intentional leaks (A: Quattro®, [Resmed]; B: Amara® [Respironics]; C: Forma® [Fisher&Paykel]) in healthy subjects. Seventeen healthy volunteers were included in this prospective cross-sectional, randomized, double-blinded trial. Each subject underwent ventilation with a home ventilator (IPAP: 14 cmH2O; EPAP: 4 cmH2O) with each mask consecutively. Transcutaneous capnography (PtcCO2) recordings were carried out throughout the trial and ventilator data (tidal volume, respiratory rate, minute ventilation and unintentional leaks) were also analyzed. Mask comfort was assessed using a visual analog scale (0 to 10). The results showed no differences in PtcCO2 between masks (P=0.82). There were no significant differences in respiratory parameters (tidal volume, P=0.79; respiratory rate, P=0.65; minute ventilation, P=0.12) between masks. The rate of unintentional leaks were significantly lower for Mask A (P=0.016). Subjects rated Mask A and Mask C as more comfortable than Mask B (P=0.041). There was no effect of mask on PtcCO2 in healthy subjects. The mask with the highest comfort rating had not the lowest rate of unintentional leaks.

Safety considerations for wireless delivery of continuous power to implanted medical devices.

PubMed

Lucke, Lori; Bluvshtein, Vlad

2014-01-01

Wireless power systems for use with implants are referred to as transcutaneous energy transmission systems (TETS) and consist of an implanted secondary coil and an external primary coil along with supporting electronics. A TETS system could be used to power ventricular assist systems and eliminate driveline infections. There are both direct and indirect safety concerns that must be addressed when continuously transferring power through the skin. Direct safety concerns include thermal tissue damage caused by exposure to the electromagnetic fields, coil heating effects, and potential unwanted nerve stimulation. Indirect concerns are those caused by potential interference of the TETS system with other implanted devices. Wireless power systems are trending towards higher frequency operation. Understanding the limits for safe operation of a TETS system across a range of frequencies is important. A low frequency and a high frequency implementation are simulated to demonstrate the impact of this trend for a VAD application.

[transcutaneous oximetry--between theory and practice].

PubMed

Zulec, Mirna

2014-10-01

Transcutaneous oximetry is a procedure used to measure the pressure of oxygen in tissue and to determine oxygenation level. It is essential to determine the state of microcirculation and is used to assess the necessity and level of amputation and the effect of revascularization procedures, as a predictor of wound healing and hyperbaric oxygen therapy (HBOT) effectiveness tool. The measurement is done by the application electrode measuring point and the result is measured in mm Hg. Tissue with adequate oxygen level has a value greater than 50 mm Hg. Values between 20 and 40 mm Hg are considered hypoxic, while those below 20 mm Hg indicate extreme hypoxia. In Croatia, TcPO2 is commonly used for HBOT assessment but there is the need of broader application to objectify and facilitate procedures in the care of persons with impaired microcirculation.

Ultrasound-Guided Transcutaneous Needle Biopsy of the Base of the Tongue and Floor of the Mouth From a Submental Approach.

PubMed

Wagner, Jason M; Conrad, Rachel D; Cannon, Trinitia Y; Alleman, Anthony M

2016-05-01

Limited data exist regarding the feasibility of ultrasound-guided transcutaneous biopsy of the base of the tongue and floor of the mouth. This retrospective study reviewed 8 cases with lesions in the base of the tongue or floor of the mouth that were biopsied by fine-needle aspiration. Core biopsy was also needed in 1 case. All biopsies were technically successful, and all yielded squamous cell carcinoma. One biopsy yielded a false-positive result, as subsequent resection yielded high-grade dysplasia with no invasion. The other biopsy results were considered true-positive based on subsequent pathologic examinations (2 cases) or clinical/imaging follow-up (5 cases). There were no significant complications associated with the biopsies. © 2016 by the American Institute of Ultrasound in Medicine.

[Clinical study on patients with renal-cell carcinoma accompanied with Von Hippel-Lindau disease treated with radiofrequency ablation].

PubMed

Nao, Tomoya; Shimamoto, Tsutomu; Karashima, Takashi; Kamei, Maiko; Fukuhara, Hideo; Fukata, Satoshi; Satake, Hirofumi; Ashida, Shingo; Yamasaki, Ichiro; Kamata, Masayuki; Inoue, Keiji; Yamanishi, Tomoaki; Ogawa, Yasuhiro; Ito, Satoshi; Shuin, Taro

2014-09-01

We report 12 renal cell carcinomas in 6 patients with Von Hippel-Lindau (VHL) disease treated with radiofrequency ablation (RFA). The mean age of the patients was 46 (range 38-53) years (male : 4, female : 2). Computed tomography (CT)-guided transcutaneous RFA was performed under conscious sedation with local anesthetics. The mean size of the tumors was 2.4 (range 0.7-8.1) cm. Nine of the 12 tumors (75%) were locally well controlled. However, 3 tumors in 2 patients developed visceral metastases after RFA. While minimal flank pain, nausea, perinephritic hematoma and lumbago were observed, there was no major complication during or after the procedure. The therapy with CT-guided transcutaneous RFA is efficient and minimal invasive for renal cell carcinoma in patients with VHL, leading to preservation of renal function.

Standardized Approach to Quantitatively Measure Residual Limb Skin Health in Individuals with Lower Limb Amputation.

PubMed

Rink, Cameron L; Wernke, Matthew M; Powell, Heather M; Tornero, Mark; Gnyawali, Surya C; Schroeder, Ryan M; Kim, Jayne Y; Denune, Jeffrey A; Albury, Alexander W; Gordillo, Gayle M; Colvin, James M; Sen, Chandan K

2017-07-01

Objective: (1) Develop a standardized approach to quantitatively measure residual limb skin health. (2) Report reference residual limb skin health values in people with transtibial and transfemoral amputation. Approach: Residual limb health outcomes in individuals with transtibial ( n  = 5) and transfemoral ( n  = 5) amputation were compared to able-limb controls ( n  = 4) using noninvasive imaging (hyperspectral imaging and laser speckle flowmetry) and probe-based approaches (laser doppler flowmetry, transcutaneous oxygen, transepidermal water loss, surface electrical capacitance). Results: A standardized methodology that employs noninvasive imaging and probe-based approaches to measure residual limb skin health are described. Compared to able-limb controls, individuals with transtibial and transfemoral amputation have significantly lower transcutaneous oxygen tension, higher transepidermal water loss, and higher surface electrical capacitance in the residual limb. Innovation: Residual limb health as a critical component of prosthesis rehabilitation for individuals with lower limb amputation is understudied in part due to a lack of clinical measures. Here, we present a standardized approach to measure residual limb health in people with transtibial and transfemoral amputation. Conclusion: Technology advances in noninvasive imaging and probe-based measures are leveraged to develop a standardized approach to quantitatively measure residual limb health in individuals with lower limb loss. Compared to able-limb controls, resting residual limb physiology in people that have had transfemoral or transtibial amputation is characterized by lower transcutaneous oxygen tension and poorer skin barrier function.

Transdermal drug delivery of insulin with ultradeformable carriers.

PubMed

Cevc, Gregor

2003-01-01

For a long time, scientists believed that macromolecules can only be introduced through the skin with a hypodermic needle or some other harsh treatment that locally damages the skin barrier. It is now clear that macromolecules can be administered epicutaneously, so that insulin, for example, can exhibit therapeutic effects in patients with type 1 diabetes mellitus. When carriers are employed for the purpose, the drugs must be associated with specifically designed vehicles in the form of highly deformable aggregates and applied on the skin non-occlusively. Using such optimised carriers, so-called Transfersomes, ensures reproducible and efficient transcutaneous carrier and drug transport. Insulin-loaded Transfersomes, for example, can deliver the drug through the non-compromised skin barrier with a reproducible drug effect that resembles closely that of an ultralente insulin injected under the skin; the pharmacokinetic and pharmacodynamic properties of the injected and transdermal insulin are also comparable. The efficacy of transcutaneously delivered insulin in Transfersomes is not affected by the previous therapy, similar results having been measured in patients normally receiving intensified insulin therapy or a continuous subcutaneous infusion of insulin solution. Systemic normoglycaemia that lasts at least 16 hours has been achieved using a single non-invasive, epicutaneous administration of insulin in Transfersomes. Experience with other drugs suggests that the biodistribution of injected and transcutaneously delivered drugs can be very similar. This notwithstanding, Transfersomes can be designed and applied so as to mediate site-specific drug delivery into peripheral musculoskeletal tissues or into the skin, as may be desired.

Occurence of adverse events due to continuous glucose monitoring.

PubMed

Jadviscokova, Tereza; Fajkusova, Zuzana; Pallayova, Maria; Luza, Jiri; Kuzmina, Galina

2007-12-01

Continuous glucose monitoring (CGM) using transcutaneous sensors is becoming a sophisticated method to control and regulate glucose metabolism. The transcutaneous sensor of the CGM system (CGMS Medtronic Minimed, Northridge, CA, USA) is chosen to measure glucose concentration in interstitial fluid up to three days after insertion even though its function remains stable for a longer period. The question arises, which factors really limit the period of sensor insertion without unnecessary risk. The aim of this study was to assess any adverse events occurring in the course of 9 days after the sensor insertion. In a group of 22 healthy volunteers aged 21.8+/-1.30 y (mean +/- SE) a total of 26 sensors was inserted subcutaneously in gluteal or lumbar region for 9 days. Before insertion the site was sprayed with an antiseptic (Cutasept F, Bode Chemie, Hamburg, Germany). Local adverse reactions and disturbances in general condition were examined. In the course of 184 sensor-days, there were only minor local adverse events: hypersensitivity, itching, pain, redness, burning, subcutaneous hemorrhage. Additionally, sleep disturbances, attention deficits, problems related to the CGMS monitor, to adhesive tape and/or sensor were found. None of these resulted in sensor withdrawal. In 12 volunteers (55 %) no complications were observed. The sensor function measured according to electrical signals (ISIG) failed (always on day 1-2) in 4 cases (16 %). The present FDA approved 3-day insertion period for Medtronic transcutaneous sensor does not seem to limit its use and appears to be worth a careful revision.

Immediate effects of transcutaneous electrical stimulation on physiological swallowing effort in older versus young adults.

PubMed

Berretin-Felix, Giédre; Sia, Isaac; Barikroo, Ali; Carnaby, Giselle D; Crary, Michael A

2016-09-01

This study compared the immediate impact of different transcutaneous electrical stimulation (TES) amplitudes on physiological swallowing effort in healthy older adults versus young adults. Swallowing physiology changes with age. Reduced physiological swallowing effort in older adults including lower lingua-palatal and pharyngeal pressures may increase risk for swallowing dysfunction (i.e. dysphagia). Transcutaneous electrical stimulation (TES) has been advocated as an adjunctive modality to enhance outcomes in exercise-based therapy for individuals with dysphagia. However, significant variation in how TES is applied during therapy remains and the physiological swallowing response to TES is poorly studied, especially in older adults. Physiological change in swallowing associated with no stimulation, sensory stimulation and motor stimulation was compared in 20 young adults versus 14 older adults. Lingua-palatal and pharyngeal manometric pressures assessed physiological swallowing effort. Multivariate analyses identified interactions between age and stimulation amplitude on lingual and pharyngeal functions. Motor stimulation reduced anterior tongue pressure in both age groups but selectively reduced posterior lingua-palatal pressures in young adults only. Sensory stimulation increased base of tongue (BOT) pressures in older adults but decreased BOT pressures in young adults. Motor stimulation increased hypopharyngeal pressures in both groups. Age and TES level interact in determining immediate physiological responses on swallow performance. A one-size-fit-all approach to TES in dysphagia rehabilitation may be misdirected. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Transcutaneous regional venous oximetry: a feasibility study.

PubMed

Thiele, Robert H; Tucker-Schwartz, Jason M; Lu, Yao; Gillies, George T; Durieux, Marcel E

2011-06-01

The arterial pulse oximeter, which was introduced clinically in the 1970s, is a convenient, useful, and now ubiquitous anesthesia monitor. Unfortunately, although percent saturation of arterial hemoglobin is, along with cardiac output and concentration of hemoglobin, one of 3 components of oxygen delivery, it does not indicate whether oxygen delivery to a region of interest is adequate. Knowledge of peripheral or regional venous oxygen saturation (Sxvo₂) may lend insight into analysis of regional oxygen supply and demand. Our goal was to assess the suitability of 3 anatomic sites for the transcutaneous assessment of Sxvo₂. Using a Nonin reflectance oximetry probe (provided by Nonin Medical, Plymouth, MN) placed directly over the antecubital, external jugular, and internal jugular veins in 10 volunteers, we measured the absorbance of red and infrared electromagnetic radiation. We performed fast Fourier transformation on these absorbance waveforms. The ratio of pulsatile absorbance of red and infrared radiation at different frequencies was compared with nonpulsatile absorption, and Sxvo₂ was calculated based on previously derived empiric correlations. Estimates of transcutaneous Sxvo₂ ranged from 41% to 97%, with mean values of 75%, 80%, and 80% at the antecubital, external jugular, and internal jugular veins, respectively. Overall, 93% of predicted Sxvo₂ values were < 90%. Validation and subsequent improvement of this technique requires correlation of our results with venous blood gas measurements, followed by incorporation of technologies from related fields in oximetry (fetal reflectance oximetry and near-infrared spectroscopy), as well as the development of advanced signal processing techniques.

Short-duration transcutaneous electrical nerve stimulation in the postoperative period of cardiac surgery.

PubMed

Gregorini, Cristie; Cipriano Junior, Gerson; Aquino, Leticia Moraes de; Branco, João Nelson Rodrigues; Bernardelli, Graziella França

2010-03-01

Respiratory muscle strength has been related to the postoperative outcome of cardiac surgeries. The main documented therapeutic purpose of transcutaneous electrical nerve stimulation (TENS) is the reduction of pain, which could bring secondary benefits to the respiratory muscles and, consequently, to lung capacities and volumes. The objective of the present study was to evaluate the effectiveness of short-duration transcutaneous electrical nerve stimulation (TENS) in the reduction of pain and its possible influence on respiratory muscle strength and lung capacity and volumes of patients in the postoperative period of cardiac surgery. Twenty five patients with mean age of 59.9 +/- 10.3 years, of whom 72% were men, and homogeneous as regards weight and height, were randomly assigned to two groups. One group received therapeutic TENS (n = 13) and the other, placebo TENS (n = 12), for four hours on the third postoperative day of cardiac surgery. Pain was analyzed by means of a visual analogue scale, and of respiratory muscle strength as measured by maximum respiratory pressures and lung capacity and volumes before and after application of TENS. Short-duration TENS significantly reduced pain of patients in the postoperative period (p < 0.001). Respiratory muscle strength (p < 0.001), tidal volume (p < 0.001) and vital capacity (p < 0.05) significantly improved after therapeutic TENS, unlike in the placebo group. Short-duration TENS proved effective for the reduction of pain and improvement of respiratory muscle strength, as well as of lung volumes and capacity.

SdrF, a Staphylococcus epidermidis Surface Protein, Contributes to the Initiation of Ventricular Assist Device Driveline–Related Infections

PubMed Central

Arrecubieta, Carlos; Toba, Faustino A.; von Bayern, Manuel; Akashi, Hirokazu; Deng, Mario C.; Naka, Yoshifumi; Lowy, Franklin D.

2009-01-01

Staphylococcus epidermidis remains the predominant pathogen in prosthetic-device infections. Ventricular assist devices, a recently developed form of therapy for end-stage congestive heart failure, have had considerable success. However, infections, most often caused by Staphylococcus epidermidis, have limited their long-term use. The transcutaneous driveline entry site acts as a potential portal of entry for bacteria, allowing development of either localized or systemic infections. A novel in vitro binding assay using explanted drivelines obtained from patients undergoing transplantation and a heterologous lactococcal system of surface protein expression were used to identify S. epidermidis surface components involved in the pathogenesis of driveline infections. Of the four components tested, SdrF, SdrG, PIA, and GehD, SdrF was identified as the primary ligand. SdrF adherence was mediated via its B domain attaching to host collagen deposited on the surface of the driveline. Antibodies directed against SdrF reduced adherence of S. epidermidis to the drivelines. SdrF was also found to adhere with high affinity to Dacron, the hydrophobic polymeric outer surface of drivelines. Solid phase binding assays showed that SdrF was also able to adhere to other hydrophobic artificial materials such as polystyrene. A murine model of infection was developed and used to test the role of SdrF during in vivo driveline infection. SdrF alone was able to mediate bacterial adherence to implanted drivelines. Anti-SdrF antibodies reduced S. epidermidis colonization of implanted drivelines. SdrF appears to play a key role in the initiation of ventricular assist device driveline infections caused by S. epidermidis. This pluripotential adherence capacity provides a potential pathway to infection with SdrF-positive commensal staphylococci first adhering to the external Dacron-coated driveline at the transcutaneous entry site, then spreading along the collagen-coated internal portion of the driveline to establish a localized infection. This capacity may also have relevance for other prosthetic device–related infections. PMID:19412528

The use of transcutaneous electrical nerve stimulation (TENS) in a major cancer center for the treatment of severe cancer-related pain and associated disability.

PubMed

Loh, Jeffrey; Gulati, Amitabh

2015-06-01

Cancer pain is difficult to treat, often requiring a multimodal approach. While medication management remains the mainstay for the treatment of cancer pain, medications are often associated with undesired side effects. Transcutaneous electrical nerve stimulation (TENS) provides a potential adjunctive method for treating cancer pain with minimal side effects. Few studies have been performed evaluating the efficacy of TENS on cancer pain. We sought to examine the usefulness of TENS on all cancer patients and to specifically look at the use of TENS as a goal-directed therapy to improve functionality. Retrospective cohort study. Since 2008, patients with chronic cancer pain and on multimodal pain regimens were trialed with TENS. Those patients who showed an improvement in pain symptoms or severity were educated about and provided with a TENS unit for use at home. Pain symptoms and scores were monitored with the visual analog scale (VAS), the numerical rating pain (NRP) scale, and Short-Form McGill Questionnaire at the start of TENS treatment and at 2 months follow-up. TENS proved beneficial in 69.7% of patients over the course of 2 months. In TENS responsive patients, VAS scores decreased by 9.8 on a 0-100 mm scale (P < 0.001), and NRP scores decreased by 0.8 on a 1-10 scale (P < 0.001). Lack of placebo and lack of blinding of physician and patient. TENS provides a beneficial adjunct for the treatment of cancer pain, especially when utilized as a goal-directed therapy. Wiley Periodicals, Inc.

Low-power transcutaneous current stimulator for wearable applications.

PubMed

Karpul, David; Cohen, Gregory K; Gargiulo, Gaetano D; van Schaik, André; McIntyre, Sarah; Breen, Paul P

2017-10-03

Peripheral neuropathic desensitization associated with aging, diabetes, alcoholism and HIV/AIDS, affects tens of millions of people worldwide, and there is little or no treatment available to improve sensory function. Recent studies that apply imperceptible continuous vibration or electrical stimulation have shown promise in improving sensitivity in both diseased and healthy participants. This class of interventions only has an effect during application, necessitating the design of a wearable device for everyday use. We present a circuit that allows for a low-power, low-cost and small form factor implementation of a current stimulator for the continuous application of subthreshold currents. This circuit acts as a voltage-to-current converter and has been tested to drive + 1 to - 1 mA into a 60 k[Formula: see text] load from DC to 1 kHz. Driving a 60 k[Formula: see text] load with a 2 mA peak-to-peak 1 kHz sinusoid, the circuit draws less than 21 mA from a 9 V source. The minimum operating current of the circuit is less than 12 mA. Voltage compliance is ± 60 V with just 1.02 mA drawn by the high voltage current drive circuitry. The circuit was implemented as a compact 46 mm × 21 mm two-layer PCB highlighting its potential for use in a body-worn device. No design to the best of our knowledge presents comparably low quiescent power with such high voltage compliance. This makes the design uniquely appropriate for low-power transcutaneous current stimulation in wearable applications. Further development of driving and instrumentation circuitry is recommended.

Nanoparticles for transcutaneous vaccination.

PubMed

Hansen, Steffi; Lehr, Claus-Michael

2012-03-01

The living epidermis and dermis are rich in antigen presenting cells (APCs). Their activation can elicit a strong humoral and cellular immune response as well as mucosal immunity. Therefore, the skin is a very attractive site for vaccination, and an intradermal application of antigen may be much more effective than a subcutaneous or intramuscular injection. However, the stratum corneum (SC) is a most effective barrier against the invasion of topically applied vaccines. Products which have reached the stage of clinical testing, avoid this problem by injecting the nano-vaccine intradermally or by employing a barrier disrupting method and applying the vaccine to a relatively large skin area. Needle-free vaccination is desirable from a number of aspects: ease of application, improved patient acceptance and less risk of infection among them. Nanocarriers can be designed in a way that they can overcome the SC. Also incorporation into nanocarriers protects instable antigen from degradation, improves uptake and processing by APCs, and facilitates endosomal escape and nuclear delivery of DNA vaccines. In addition, sustained release systems may build a depot in the tissue gradually releasing antigen which may avoid booster doses. Therefore, nanoformulations of vaccines for transcutaneous immunization are currently a very dynamic field of research. Among the huge variety of nanocarrier systems that are investigated hopes lie on ultra-flexible liposomes, superfine rigid nanoparticles and nanocarriers, which are taken up by hair follicles. The potential and pitfalls associated with these three classes of carriers will be discussed. © 2011 The Authors; Microbial Biotechnology © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

Design and Development of a Miniaturized Percutaneously Deployable Wireless Left Ventricular Assist Device: Early Prototypes and Feasibility Testing.

PubMed

Letzen, Brian; Park, Jiheum; Tuzun, Zeynep; Bonde, Pramod

The current left ventricular assist devices (LVADs) are limited by a highly invasive implantation procedure in a severely unstable group of advanced heart failure patients. Additionally, the current transcutaneous power drive line acts as a nidus for infection resulting in significant morbidity and mortality. In an effort to decrease this invasiveness and eliminate drive line complications, we have conceived a wireless miniaturized percutaneous LVAD, capable of being delivered endovascularly with a tether-free operation. The system obviates the need for a transcutaneous fluid purge line required in existing temporary devices by utilizing an incorporated magnetically coupled impeller for a complete seal. The objective of this article was to demonstrate early development and proof-of-concept feasibility testing to serve as the groundwork for future formalized device development. Five early prototypes were designed and constructed to iteratively minimize the pump size and improve fluid dynamic performance. Various magnetic coupling configurations were tested. Using SolidWorks and ANSYS software for modeling and simulation, several geometric parameters were varied. HQ curves were constructed from preliminary in vitro testing to characterize the pump performance. Bench top tests showed no-slip magnetic coupling of the impeller to the driveshaft up to the current limit of the motor. The pump power requirements were tested in vitro and were within the appropriate range for powering via a wireless energy transfer system. Our results demonstrate the proof-of-concept feasibility of a novel endovascular cardiac assist device with the potential to eventually offer patients an untethered, minimally invasive support.

Hand gesture guided robot-assisted surgery based on a direct augmented reality interface.

PubMed

Wen, Rong; Tay, Wei-Liang; Nguyen, Binh P; Chng, Chin-Boon; Chui, Chee-Kong

2014-09-01

Radiofrequency (RF) ablation is a good alternative to hepatic resection for treatment of liver tumors. However, accurate needle insertion requires precise hand-eye coordination and is also affected by the difficulty of RF needle navigation. This paper proposes a cooperative surgical robot system, guided by hand gestures and supported by an augmented reality (AR)-based surgical field, for robot-assisted percutaneous treatment. It establishes a robot-assisted natural AR guidance mechanism that incorporates the advantages of the following three aspects: AR visual guidance information, surgeon's experiences and accuracy of robotic surgery. A projector-based AR environment is directly overlaid on a patient to display preoperative and intraoperative information, while a mobile surgical robot system implements specified RF needle insertion plans. Natural hand gestures are used as an intuitive and robust method to interact with both the AR system and surgical robot. The proposed system was evaluated on a mannequin model. Experimental results demonstrated that hand gesture guidance was able to effectively guide the surgical robot, and the robot-assisted implementation was found to improve the accuracy of needle insertion. This human-robot cooperative mechanism is a promising approach for precise transcutaneous ablation therapy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

[The endo-exo femur prosthesis--a new concept of bone-guided, prosthetic rehabilitation following above-knee amputation].

PubMed

Aschoff, H H; Clausen, A; Hoffmeister, T

2009-01-01

The implantation of an intramedullary transcutaneously conducted femur prosthesis presents a rather new procedure for the rehabilitation of above-knee amputated patients. The aim of the so-called endo-exo prosthesis is to avoid the well-known problems at the interface between the sleeve of the prosthesis and the soft tissue coat of the femur stump which often impedes an inconspicuous and harmonic gait. The company ERSKA Implants in Lübeck/Germany has developed an intramedullary femur prosthesis with a spongiosa metal-configurated relief surface which, when implanted cementless, enables a secure osseointegration and allows a more direct transmission of muscle power to the lower leg prosthesis. A minimum length of 16-18 cm and a sufficient soft tissue coverage of the femur stump is needed. The problems at the perforation point of the implant through the soft tissue coat can be handled or even be avoided and they do not necessarily provoke an intramedullary infection. We report on 30 cases that were operated between 1999 and 2008. The design of the prosthesis, aspects of the operative procedure and latest results are presented.

Association of Transcutaneous Electrical Nerve Stimulation and Hypnosis

ClinicalTrials.gov

2017-08-02

Limbs Arthrosis; Non Arthrosic Limbs Arthralgia; Chronic Lomboradiculalgia; Chronic Back Pain; Cervical Radiculopathy; Post-herpetic Neuralgia; Post-surgical Peripheral Neuropathic Pain; Post Trauma Neuropathic Pain; Complex Regional Pain Syndrome Type I or II; Tendinopathy

Evaluation of phrenic nerve and diaphragm function with peripheral nerve stimulation and M-mode ultrasonography in potential pediatric phrenic nerve or diaphragm pacing candidates.

PubMed

Skalsky, Andrew J; Lesser, Daniel J; McDonald, Craig M

2015-02-01

Assessing phrenic nerve function in the setting of diaphragmatic paralysis in diaphragm pacing candidates can be challenging. Traditional imaging modalities and electrodiagnostic evaluations are technically difficult. Either modality alone is not a direct measure of the function of the phrenic nerve and diaphragm unit. In this article, the authors present their method for evaluating phrenic nerve function and the resulting diaphragm function. Stimulating the phrenic nerve with transcutaneous stimulation and directly observing the resulting movement of the hemidiaphragm with M-mode ultrasonography provides quantitative data for predicting the success of advancing technologies such as phrenic nerve pacing and diaphragm pacing. Copyright © 2015 Elsevier Inc. All rights reserved.

Transcutaneous electric nerve stimulation (TENS) in dentistry- A review.

PubMed

Kasat, Vikrant; Gupta, Aditi; Ladda, Ruchi; Kathariya, Mitesh; Saluja, Harish; Farooqui, Anjum-Ara

2014-12-01

Transcutaneous electric nerve stimulation (TENS) is a non-pharmacological method which is widely used by medical and paramedical professionals for the management of acute and chronic pain in a variety of conditions. Similarly, it can be utilized for the management of pain during various dental procedures as well as pain due to various conditions affecting maxillofacial region. This review aims to provide an insight into clinical research evidence available for the analgesic and non analgesic uses of TENS in pediatric as well as adult patients related to the field of dentistry. Also, an attempt is made to briefly discuss history of therapeutic electricity, mechanism of action of TENS, components of TENs equipment, types, techniques of administration, advantages and contradictions of TENS. With this we hope to raise awareness among dental fraternity regarding its dental applications thereby increasing its use in dentistry. Key words:Dentistry, pain, TENS.

Transcutaneous electric nerve stimulation (TENS) in dentistry- A review

PubMed Central

Gupta, Aditi; Ladda, Ruchi; Kathariya, Mitesh; Saluja, Harish; Farooqui, Anjum-Ara

2014-01-01

Transcutaneous electric nerve stimulation (TENS) is a non-pharmacological method which is widely used by medical and paramedical professionals for the management of acute and chronic pain in a variety of conditions. Similarly, it can be utilized for the management of pain during various dental procedures as well as pain due to various conditions affecting maxillofacial region. This review aims to provide an insight into clinical research evidence available for the analgesic and non analgesic uses of TENS in pediatric as well as adult patients related to the field of dentistry. Also, an attempt is made to briefly discuss history of therapeutic electricity, mechanism of action of TENS, components of TENs equipment, types, techniques of administration, advantages and contradictions of TENS. With this we hope to raise awareness among dental fraternity regarding its dental applications thereby increasing its use in dentistry. Key words:Dentistry, pain, TENS. PMID:25674327

Use of electroacupuncture and transcutaneous electrical acupoint stimulation in reproductive medicine: a group consensus.

PubMed

Qu, Fan; Li, Rong; Sun, Wei; Lin, Ge; Zhang, Rong; Yang, Jing; Tian, Li; Xing, Guo-Gang; Jiang, Hui; Gong, Fei; Liang, Xiao-Yan; Meng, Yan; Liu, Jia-Yin; Zhou, Li-Ying; Wang, Shu-Yu; Wu, Yan; He, Yi-Jing; Ye, Jia-Yu; Han, Song-Ping; Han, Ji-Sheng

With the rapid development of assisted reproductive technology, various reproductive disorders have been effectively addressed. Acupuncture-like therapies, including electroacupuncture (EA) and transcutaneous electrical acupoint stimulation (TEAS), become more popular world-wide. Increasing evidence has demonstrated that EA and TEAS are effective in treating gynecological disorders, especially infertility. This present paper describes how to select acupoints for the treatment of infertility from the view of theories of traditional Chinese medicine and how to determine critical parameters of electric pulses of EA/TEAS based on results from animal and clinical studies. It summarizes the principles of clinical application of EA/TEAS in treating various kinds of reproductive disorders, such as polycystic ovary syndrome (PCOS), pain induced by oocyte retrieval, diminished ovarian reserve, embryo transfer, and oligospermia/ asthenospermia. The possible underlying mechanisms mediating the therapeutic effects of EA/TEAS in reproductive medicine are also examined.

3D splint prototype system for applications in muscular rehab by transcutaneous electrical nerve stimulation (TENS)

NASA Astrophysics Data System (ADS)

Saldaña-Martínez, M. I.; Guzmán-González, J. V.; Barajas-González, O. G.; Guzman-Ramos, V.; García-Garza, A. K.; González-García, R. B.; García-Ramírez, M. A.

2017-03-01

It is quite common that patients with ligamentous ruptures, tendonitis, tenosynovitis or sprains are foreseen the use of ad hoc splints for a swift recovery. In this paper, we propose a rehabilitation split that is focused on upper-limb injuries. By considering that upper-limb patient shows a set of different characteristics, our proposal personalizes and prints the splint custom made though a digital model that is generated by a 3D commercial scanner. To fabricate the 3D scanned model the Stereolithography material (SLA) is considered due to the properties that this material offers. In order to complement the recovery process, an electronic system is implemented within the splint design. This system generates a set of pulses for a fix period of time that focuses mainly on a certain group of muscles to allow a fast recovery process known as Transcutaneous Electrical Nerve Stimulation Principle (TENS).

Electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter system*

PubMed Central

Zan, Peng; Yang, Bang-hua; Shao, Yong; Yan, Guo-zheng; Liu, Hua

2010-01-01

This paper reports on the electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter. The coupling coils and human tissues, including the skin, fat, muscle, liver, and blood, were considered. Specific absorption rate (SAR) and current density were analyzed by a finite-length solenoid model. First, SAR and current density as a function of frequency (10–107 Hz) for an emission current of 1.5 A were calculated under different tissue thickness. Then relations between SAR, current density, and five types of tissues under each frequency were deduced. As a result, both the SAR and current density were below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The results show that the analysis of these data is very important for developing the artificial anal sphincter system. PMID:21121071

Electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter system.

PubMed

Zan, Peng; Yang, Bang-hua; Shao, Yong; Yan, Guo-zheng; Liu, Hua

2010-12-01

This paper reports on the electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter. The coupling coils and human tissues, including the skin, fat, muscle, liver, and blood, were considered. Specific absorption rate (SAR) and current density were analyzed by a finite-length solenoid model. First, SAR and current density as a function of frequency (10-10(7) Hz) for an emission current of 1.5 A were calculated under different tissue thickness. Then relations between SAR, current density, and five types of tissues under each frequency were deduced. As a result, both the SAR and current density were below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The results show that the analysis of these data is very important for developing the artificial anal sphincter system.

[Transcutaneous electrical nervous stimulation in the prognosis of Bell's palsy].

PubMed

Sabag-Ruiz, Enrique; Osuna-Bernal, Janeth; Brito-Zurita, Olga Rosa; Gómez-Alcalá, Alejandro Vidal; Ornelas-Aguirre, José Manuel

2009-01-01

The peripheral face palsy (PFP) is the commonest acute cranial neuropathy. The PFP has a showy clinical pattern which contrasts with a favorable course. Our objective was to determine the sensitivity and specificity for the nervous excitability test (NET) with transcutaneous electrical nerve stimulation (TENS) and the time required to obtain face symmetry. An analytical cross-sectional study was made in 22 patients with PFP. The goal was the time (days) to obtain face symmetry. The sensitivity and specificity was carried out. A sensitivity and specificity of the NET was of 100 %. The correlation corrected by sex and age between both variables was 0.89. The average in days of recovery was smaller in those with a positive NET (p < 0.05) test. The test of nervous excitability for PFP with TENS is safe and simple to use in primary care and urgencies services.

Effects of transcutaneous electrical nerve stimulation on pain intensity during application of carboxytherapy in patients with cellulite: A randomized placebo-controlled trial.

PubMed

Sadala, Adria Y; Machado, Aline F P; Liebano, Richard E

2018-01-16

Carboxytherapy may generate local pain that is considered the main limiting factor in clinical practice. Transcutaneous electric nerve stimulation (TENS) is widely used in the control of acute pain; however, the effect of TENS on pain relief during carboxytherapy has not been studied to date. To assess the effect of TENS on pain intensity during carboxytherapy in patients with cellulite in the gluteal region. This randomized clinical trial was conducted with 84 patients, 18-44 years of age, who had moderate cellulite in the gluteal region, according to Cellulite Severity Scale, but never received carboxytherapy. Patients were randomized into 3 groups: active TENS, placebo TENS, and control group. For the intervention, skin depressions with cellulite were outlined, and the gluteal area to be treated was defined. The subcutaneous injection of CO 2 was performed using 0.30 × 13 mm-needles at a 45° angle, with a controlled flow rate of 100 mL/min maintained for 1 minute at each puncture site. The parameters for TENS were as follows: frequency of 100 Hz and pulse duration of 200 μs; TENS intensity was adjusted until the patient reported strong paresthesia. The visual numeric pain rating scale was used to assess pain intensity after each puncture. The active TENS group reported lower pain intensity compared to the placebo TENS (P < .0001) and control (P < .0001) groups. Transcutaneous electric nerve stimulation (TENS) was effective in reducing pain intensity during carboxytherapy in patients with cellulite in the gluteal region. © 2018 Wiley Periodicals, Inc.

Microcurrent transcutaneous electric nerve stimulation in painful diabetic neuropathy: a randomized placebo-controlled study.

PubMed

Gossrau, Gudrun; Wähner, Michael; Kuschke, Marion; Konrad, Birgit; Reichmann, Heinz; Wiedemann, Bärbel; Sabatowski, Rainer

2011-06-01

Diabetes is a common health care problem in western countries. Painful diabetic neuropathy (PDN) might be one of the consequences of long ongoing diabetes; it is estimated that approximately 20% of European diabetic patients suffer from PDN. Transcutaneous electrical nerve stimulation (TENS) is often used as additional pain treatment. However, recent studies show inconsistent results. We aimed to assess the effect of micro-TENS in reducing neuropathic pain in patients with PDN in a placebo-controlled, single-blinded, and randomized design. DESIGN/SETTING/PATIENTS/OUTCOME MEASURES: 22 diabetic patients have been treated with a micro-TENS therapy and 19 patients have been treated with a placebo therapy. Treatment duration was 4 weeks with three therapeutical settings per week. Standardized questionnaires (Pain Disability Index [PDI], neuropathic pain score [NPS], Center for Epidemiologic Studies Depression Scale [CES-D]) were used to assess pain intensity, pain disability, as well as quality of life at baseline at the end of the treatment period and 4 weeks after treatment termination. Patients with a minimum of 30% reduction in NPS were defined as therapy responders. After 4 weeks of treatment, 6/21 patients in the verum group vs 10/19 patients in the placebo group responded to therapy. The median PDI score after 4 weeks of treatment showed a reduction of 23% in the verum vs 25% in the placebo group. The differences did not reach statistical significance. The pain reduction with the applied transcutaneous electrotherapy regimen is not superior to a placebo treatment. Wiley Periodicals, Inc.

Method to Reduce Muscle Fatigue During Transcutaneous Neuromuscular Electrical Stimulation in Major Knee and Ankle Muscle Groups.

PubMed

Sayenko, Dimitry G; Nguyen, Robert; Hirabayashi, Tomoyo; Popovic, Milos R; Masani, Kei

2015-09-01

A critical limitation with transcutaneous neuromuscular electrical stimulation as a rehabilitative approach is the rapid onset of muscle fatigue during repeated contractions. We have developed a method called spatially distributed sequential stimulation (SDSS) to reduce muscle fatigue by distributing the center of electrical field over a wide area within a single stimulation site, using an array of surface electrodes. To extend the previous findings and to prove feasibility of the method by exploring the fatigue-reducing ability of SDSS for lower limb muscle groups in the able-bodied population, as well as in individuals with spinal cord injury (SCI). SDSS was delivered through 4 active electrodes applied to the knee extensors and flexors, plantarflexors, and dorsiflexors, sending a stimulation pulse to each electrode one after another with 90° phase shift between successive electrodes. Isometric ankle torque was measured during fatiguing stimulations using SDSS and conventional single active electrode stimulation lasting 2 minutes. We demonstrated greater fatigue-reducing ability of SDSS compared with the conventional protocol, as revealed by larger values of fatigue index and/or torque peak mean in all muscles except knee flexors of able-bodied individuals, and in all muscles tested in individuals with SCI. Our study has revealed improvements in fatigue tolerance during transcutaneous neuromuscular electrical stimulation using SDSS, a stimulation strategy that alternates activation of subcompartments of muscles. The SDSS protocol can provide greater stimulation times with less decrement in mechanical output compared with the conventional protocol. © The Author(s) 2014.

In Vivo and Ex Vivo Transcutaneous Glucose Detection Using Surface-Enhanced Raman Spectroscopy

NASA Astrophysics Data System (ADS)

Ma, Ke

Diabetes mellitus is widely acknowledged as a large and growing health concern. The lack of practical methods for continuously monitoring glucose levels causes significant difficulties in successful diabetes management. Extensive validation work has been carried out using surface-enhanced Raman spectroscopy (SERS) for in vivo glucose sensing. This dissertation details progress made towards a Raman-based glucose sensor for in vivo, transcutaneous glucose detection. The first presented study combines spatially offset Raman spectroscopy (SORS) with SERS (SESORS) to explore the possibility of in vivo, transcutaneous glucose sensing. A SERS-based glucose sensor was implanted subcutaneously in Sprague-Dawley rats. SERS spectra were acquired transcutaneously and analyzed using partial least-squares (PLS). Highly accurate and consistent results were obtained, especially in the hypoglycemic range. Additionally, the sensor demonstrated functionality at least17 days after implantation. A subsequent study further extends the application of SESORS to the possibility of in vivo detection of glucose in brain through skull. Specifically, SERS nanoantennas were buried in an ovine tissue behind a bone with 8 mm thickness and detected by using SESORS. In addition, quantitative detection through bones by using SESORS was also demonstrated. A device that could measure glucose continuously as well as noninvasively would be of great use to patients with diabetes. The inherent limitation of the SESORS approach may prevent this technique from becoming a noninvasive method. Therefore, the prospect of using normal Raman spectroscopy for glucose detection was re-examined. Quantitative detection of glucose and lactate in the clinically relevant range was demonstrated by using normal Raman spectroscopy with low power and short acquisition time. Finally, a nonlinear calibration method called least-squares support vector machine regression (LS-SVR) was investigated for analyzing spectroscopic data sets of glucose detection. Comparison studies were demonstrated between LS-SVR and PLS. LS-SVR demonstrated significant improvements in accuracy over PLS for glucose detection, especially when a global calibration model was required. The improvements imparted by LS-SVR open up the possibility of developing an accurate prediction algorithm for Raman-based glucose sensing applicable to a large human population. Overall, these studies show the high promise held by the Raman-based sensor for the challenge of optimal glycemic control.

An induced current method for measuring zeta potential of electrolyte solution-air interface.

PubMed

Song, Yongxin; Zhao, Kai; Wang, Junsheng; Wu, Xudong; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

2014-02-15

This paper reports a novel and very simple method for measuring the zeta potential of electrolyte solution-air interface. When a measuring electrode contacts the electrolyte solution-air interface, an electrical current will be generated due to the potential difference between the electrode-air surface and the electrolyte solution-air interface. The amplitude of the measured electric signal is linearly proportional to this potential difference; and depends only on the zeta potential at the electrolyte solution-air interface, regardless of the types and concentrations of the electrolyte. A correlation between the zeta potential and the measured voltage signal is obtained based on the experimental data. Using this equation, the zeta potential of any electrolyte solution-air interface can be evaluated quickly and easily by inserting an electrode through the electrolyte solution-air interface and measuring the electrical signal amplitude. This method was verified by comparing the obtained results of NaCl, MgCl2 and CaCl2 solutions of different pH values and concentrations with the zeta potential data reported in the published journal papers. Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs.

PubMed

Charton, Antoine; Péronnet, François; Doutreleau, Stephane; Lonsdorfer, Evelyne; Klein, Alexis; Jimenez, Liliana; Geny, Bernard; Diemunsch, Pierre; Richard, Ruddy

2014-01-01

Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply.

Do the Effects of Transcutaneous Electrical Nerve Stimulation on Knee Osteoarthritis Pain and Function Last?

PubMed

Cherian, Jeffrey Jai; Harrison, Paige E; Benjamin, Samantha A; Bhave, Anil; Harwin, Steven F; Mont, Michael A

2016-08-01

Transcutaneous electrical nerve stimulation (TENS) has been shown to decrease pain associated with knee osteoarthritis, which potentially leads to better function, improved quality of life, and postpones the need for surgical intervention. The purpose of this study was to perform a 1-year follow-up of a previous prospective group of patients with knee osteoarthritis, randomized to TENS or standard of care, who were asked to rate their changes in: (1) patient pain perception; (2) subjective medication use; (3) subjective functional abilities; (4) quality of life; (5) device use; and (6) conversion to TKA. A population of 70 patients were randomized to receive either a TENS device or a standard conservative therapy regimen. Patients were evaluated based on various subjective outcomes at minimum 1-year (mean, 19 months) follow-up. The TENS cohort had lower visual analog pain scores compared with the matching cohort. Subjective functional outcomes, as well as functional and activity scores, were also greater in the TENS cohort. Patients in TENS cohort showed significant improvements in their subjective and functional outcomes as compared with their initial status, while the control group did not show significant change. A majority of the TENS patients were able to reduce the amount of pain medications. Additionally, a large portion of the patients assigned to the TENS group continue to use the device, after completion of the trial. This study demonstrated the benefit of TENS for improving subjective outcomes in patients with pain due to knee osteoarthritis, compared with standard conservative treatments. The results of the study suggest that TENS is a safe and effective adjunct as part of the spectrum of current nonoperative treatment methods for knee osteoarthritis. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Prolonged treatment with transcutaneous electrical nerve stimulation (TENS) modulates neuro-gastric motility and plasma levels of vasoactive intestinal peptide (VIP), motilin and interleukin-6 (IL-6) in systemic sclerosis.

PubMed

McNearney, Terry A; Sallam, Hanaa S; Hunnicutt, Sonya E; Doshi, Dipti; Chen, Jiande D Z

2013-01-01

We assessed the effects of transcutaneous electrical nerve stimulation (TENS) on neurogastric functioning in scleroderma patients. Seventeen SSc patients underwent 30 min TENS treatment >10Hz at GI acupuncture points PC6 and ST36, once (acute TENS) and then after two weeks of TENS sessions for 30 min twice daily (prolonged TENS). Data collected at Visits 1 and 2 included gastric myoelectrical activity (GMA) by surface electrogastrography (EGG), heart rate variability (HRV) by surface electrocardiography (EKG), GI specific symptoms and health related SF-36 questionnaires. Plasma VIP, motilin and IL-6 levels were determined. Statistical analyses were performed by Student's t-test, Spearman Rank and p-values <0.05 were considered significant. 1. Only after prolonged TENS, the percentages of normal slow waves and average slow wave coupling (especially channels 1, 2 reflecting gastric pacemaker and corpus regions) were significantly increased; 2. the percentage of normal slow waves was significantly correlated to sympathovagal balance; 3. Mean plasma VIP and motilin levels were significantly decreased after acute TENS, (vs. baseline), generally maintained in the prolonged TENS intervals. Compared to baseline, mean plasma IL-6 levels were significantly increased after acute TENS, but significantly decreased after prolonged TENS. 4. After prolonged TENS, the frequency of awakening due to abdominal pain and abdominal bloating were significantly and modestly decreased, respectively. In SSc patients, two weeks of daily TENS improved patient GMA scores, lowered plasma VIP, motilin and IL-6 levels and improved association between GMA and sympathovagal balance. This supports the therapeutic potential of prolonged TENS to enhance gastric myoelectrical functioning in SSc.

Focused ultrasound to expel calculi from the kidney: safety and efficacy of a clinical prototype device.

PubMed

Harper, Jonathan D; Sorensen, Mathew D; Cunitz, Bryan W; Wang, Yak-Nam; Simon, Julianna C; Starr, Frank; Paun, Marla; Dunmire, Barbrina; Liggitt, H Denny; Evan, Andrew P; McAteer, James A; Hsi, Ryan S; Bailey, Michael R

2013-09-01

Focused ultrasound has the potential to expel small stones or residual stone fragments from the kidney, or move obstructing stones to a nonobstructing location. We evaluated the efficacy and safety of ultrasonic propulsion in a live porcine model. Calcium oxalate monohydrate kidney stones and laboratory model stones (2 to 8 mm) were ureteroscopically implanted in the renal pelvicalyceal system of 12 kidneys in a total of 8 domestic swine. Transcutaneous ultrasonic propulsion was performed using an HDI C5-2 imaging transducer (ATL/Philips, Bothell, Washington) and the Verasonics® diagnostic ultrasound platform. Successful stone relocation was defined as stone movement from the calyx to the renal pelvis, ureteropelvic junction or proximal ureter. Efficacy and procedure time was determined. Three blinded experts evaluated histological injury to the kidney in the control, sham treatment and treatment arms. All 26 stones were observed to move during treatment and 17 (65%) were relocated successfully to the renal pelvis (3), ureteropelvic junction (2) or ureter (12). Average ± SD successful procedure time was 14 ± 8 minutes and a mean of 23 ± 16 ultrasound bursts, each about 1 second in duration, were required. There was no evidence of gross or histological injury to the renal parenchyma in kidneys exposed to 20 bursts (1 second in duration at 33-second intervals) at the same output (2,400 W/cm(2)) used to push stones. Noninvasive transcutaneous ultrasonic propulsion is a safe, effective and time efficient means to relocate calyceal stones to the renal pelvis, ureteropelvic junction or ureter. This technology holds promise as a useful adjunct to surgical management for renal calculi. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Problems, Solutions, and Strategies Reported by Users of Transcutaneous Electrical Nerve Stimulation for Chronic Musculoskeletal Pain: Qualitative Exploration Using Patient Interviews.

PubMed

Gladwell, Peter William; Badlan, Kathryn; Cramp, Fiona; Palmer, Shea

2016-07-01

Transcutaneous electrical nerve stimulation (TENS) could offer a non-drug form of pain relief, but there is no consensus regarding its effectiveness for chronic musculoskeletal pain or chronic low back pain. A recent review of previous trial methods identified significant problems with low treatment fidelity. There is little information available to inform the development of a pragmatic implementation design for a TENS evaluation. The aim of this study was to explore the experiences of patients who were receiving secondary care in a pain clinic and who had expertise in using TENS to manage chronic musculoskeletal pain. These key informants were selected because they had the potential to generate knowledge that could inform research design and clinical practice. A qualitative method using individual semistructured interviews with open questions was selected for its capacity to generate rich data. Semistructured interviews were conducted with 9 patients (6 women, 3 men). Thematic analysis was used as the primary data analysis method, and this analysis was enhanced by a case-level analysis of the context and processes of TENS use of each individual. Data analysis indicated that patients learned to address a range of problems in order to optimize TENS use. Patients may need to personalize the positioning of electrodes and the TENS settings and to readjust them over time. Patients learned to use TENS in a strategic manner, and the outcomes of each strategy varied. The findings indicated that a pragmatic TENS evaluation may need to incorporate a learning phase to allow patients to optimize this complex pattern of TENS usage, and evaluation may need to be sensitive to the outcomes of strategic use. These findings also have implications for clinical practice. © 2016 American Physical Therapy Association.

Validation of two novel electronic devices to time-link transcutaneous electrical nerve stimulation and pain report in patients with chronic back pain.

PubMed

Pallett, Edward J; Rentowl, Patricia; Watson, Paul J

2013-01-01

The analgesic effectiveness of transcutaneous electrical nerve stimulation (TENS) is uncertain. Negative findings, interpreted as ineffectiveness, might be due to poor methodological quality. Monitoring is necessary to differentiate between ineffectiveness and low implementation fidelity. Electronic data-logging devices, "TLOG" and "TSCORE," were developed to monitor and time-link TENS and pain report. TLOG records the time and duration of TENS use and output parameters; TSCORE records time-stamped pain scores. The purpose was to determine the accuracy, reliability, and acceptability of the devices. Forty-two outpatients with chronic back pain consented to use TENS daily for 2 weeks. Treatment times and durations were recorded in paper diaries and compared with TLOG data. Using TSCORE, patients reported pain before, during, and after TENS. Pain scores, reported using TSCORE or paper numerical rating scale at the beginning and end of 2 study visits, were compared using Bland-Altman methodology. The mean (SD) difference between paper and TSCORE pain scores was -0.05 (0.81). Limits of agreement (mean difference ± 1.96 SD) were -1.65 to 1.55. Test-retest reliabilities of paper and TSCORE were comparable: Paper mean (SD) difference was -0.33 (0.66), limits of agreement were -1.62 to 0.96; TSCORE mean (SD) difference was -0.10 (0.31), limits were -0.7 to 0.5. TLOG recorded TENS use accurately and worked reliably for 2 weeks in 84% of cases. An overall 79% of participants preferred TSCORE to paper numerical rating scale. TLOG and TSCORE are accurate, reliable, and acceptable devices for monitoring TENS implementation fidelity and pain outcome, with potential for improving TENS research methodology and clinical application.

Focused Ultrasound to Expel Calculi from the Kidney: Safety and Efficacy of a Clinical Prototype Device

PubMed Central

Harper, Jonathan D.; Sorensen, Mathew D.; Cunitz, Bryan W.; Wang, Yak-Nam; Simon, Julianna C.; Starr, Frank; Paun, Marla; Dunmire, Barbrina; Liggitt, H. Denny; Evan, Andrew P.; McAteer, James A.; Hsi, Ryan S.; Bailey, Michael R.

2015-01-01

Purpose Focused ultrasound has the potential to expel small stones or residual stone fragments from the kidney, or move obstructing stones to a nonobstructing location. We evaluated the efficacy and safety of ultrasonic propulsion in a live porcine model. Materials and Methods Calcium oxalate monohydrate kidney stones and laboratory model stones (2 to 8 mm) were ureteroscopically implanted in the renal pelvicalyceal system of 12 kidneys in a total of 8 domestic swine. Transcutaneous ultrasonic propulsion was performed using an HDI C5-2 imaging transducer (ATL/Philips, Bothell, Washington) and the Verasonics® diagnostic ultrasound platform. Successful stone relocation was defined as stone movement from the calyx to the renal pelvis, ureteropelvic junction or proximal ureter. Efficacy and procedure time was determined. Three blinded experts evaluated histological injury to the kidney in the control, sham treatment and treatment arms. Results All 26 stones were observed to move during treatment and 17 (65%) were relocated successfully to the renal pelvis (3), ureteropelvic junction (2) or ureter (12). Average ± SD successful procedure time was 14 ± 8 minutes and a mean of 23 ± 16 ultrasound bursts, each about 1 second in duration, were required. There was no evidence of gross or histological injury to the renal parenchyma in kidneys exposed to 20 bursts (1 second in duration at 33-second intervals) at the same output (2,400 W/cm2) used to push stones. Conclusions Noninvasive transcutaneous ultrasonic propulsion is a safe, effective and time efficient means to relocate calyceal stones to the renal pelvis, ureteropelvic junction or ureter. This technology holds promise as a useful adjunct to surgical management for renal calculi. PMID:23583535

Excision and Redraping Skin and Orbicularis Oculi Muscle Separately during Transcutaneous Lower Eyelid Blepharoplasty.

PubMed

Haefliger, I O; Pimentel de Figueiredo, A R

2015-04-01

The purpose of this study was to report a transcutaneous lower eyelid blepharoplasty procedure where different amounts of skin and orbicularis oculi muscle are excised and where skin and muscle are redraped (tightened) separately. A retrospective non-consecutive small case-series of patients undergoing lower eyelid blepharoplasty is described. In a nutshell, during this procedure a skin flap was fashioned (caudal to the sub-ciliary pre-tarsal excess of skin to be excised), some pre-septal orbicularis oculi muscle fibers were excised (in regard of the skin flap), muscle and then skin were redraped, separately. In addition to these surgical steps conducted on each patient, when required, orbital fat prolapse was reduced, orbital retaining ligament was detached, and/or a canthopexie/plasty was performed. Assessment of surgical outcome was made by providing, for comparison, pictures taken before and after the procedure. No major intra- or postoperative complications were recorded and overall postoperative outcome was judged satisfactory by both surgeons and patients. In contrast to a conventional skin-muscle lower blepharoplasty approach where, in a block, pre-tarsal skin and muscle are excised and then pre-septal skin and muscle are redraped, the technique described in the present paper allows us to excise different amounts of skin and orbicularis muscle and to redrape them separately. Among several potential advantages, this approach preserves pre-tarsal orbicularis muscle function, allows us to apply more tension on the redraped muscle and less on the redraped skin, and avoids redraping of a relatively thick per-septal orbicularis oculi muscle over the tarsus (like it is in the case of a conventional skin-muscle technique). Georg Thieme Verlag KG Stuttgart · New York.

Transcutaneous Auricular Vagus Nerve Stimulation with Concurrent Upper Limb Repetitive Task Practice for Poststroke Motor Recovery: A Pilot Study.

PubMed

Redgrave, Jessica N; Moore, Lucy; Oyekunle, Tosin; Ebrahim, Maryam; Falidas, Konstantinos; Snowdon, Nicola; Ali, Ali; Majid, Arshad

2018-03-23

Invasive vagus nerve stimulation (VNS) has the potential to enhance the effects of physiotherapy for upper limb motor recovery after stroke. Noninvasive, transcutaneous auricular branch VNS (taVNS) may have similar benefits, but this has not been evaluated in stroke recovery. We sought to determine the feasibility of taVNS delivered alongside upper limb repetitive task-specific practice after stroke and its effects on a range of outcome measures evaluating limb function. Thirteen participants at more than 3 months postischemic stroke with residual upper limb dysfunction were recruited from the community of Sheffield, United Kingdom (October-December 2016). Participants underwent 18 × 1-hour sessions over 6 weeks in which they made 30-50 repetitions of 8-10 arm movements concurrently with taVNS (NEMOS; Cerbomed, Erlangen, Germany, 25 Hz, .1-millisecond pulse width) at maximum tolerated intensity (mA). An electrocardiogram and rehabilitation outcome scores were obtained at each visit. Qualitative interviews determined the acceptability of taVNS to participants. Median time after stroke was 1.16 years, and baseline median/interquartile range upper limb Fugl-Meyer (UFM) score was 63 (54.5-99.5). Participants attended 92% of the planned treatment sessions. Three participants reported side effects, mainly fatigue, but all performed mean of more than 300 arm repetitions per session with no serious adverse events. There was a significant change in the UFM score with a mean increase per participant of 17.1 points (standard deviation 7.8). taVNS is feasible and well-tolerated alongside upper limb repetitive movements in poststroke rehabilitation. The motor improvements observed justify a phase 2 trial in patients with residual arm weakness. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs

PubMed Central

Charton, Antoine; Péronnet, François; Doutreleau, Stephane; Lonsdorfer, Evelyne; Klein, Alexis; Jimenez, Liliana; Geny, Bernard; Diemunsch, Pierre; Richard, Ruddy

2014-01-01

Background Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. Methods Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. Results Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. Conclusions In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply. PMID:25210438

Fatigue reduction during aggregated and distributed sequential stimulation.

PubMed

Bergquist, Austin J; Babbar, Vishvek; Ali, Saima; Popovic, Milos R; Masani, Kei

2017-08-01

Transcutaneous neuromuscular electrical stimulation (NMES) can generate muscle contractions for rehabilitation and exercise. However, NMES-evoked contractions are limited by fatigue when they are delivered "conventionally" (CONV) using a single active electrode. Researchers have developed "sequential" (SEQ) stimulation, involving rotation of pulses between multiple "aggregated" (AGGR-SEQ) or "distributed" (DISTR-SEQ) active electrodes, to reduce fatigue (torque-decline) by reducing motor unit discharge rates. The primary objective was to compare fatigue-related outcomes, "potentiation," "variability," and "efficiency" between CONV, AGGR-SEQ, and DISTR-SEQ stimulation of knee extensors in healthy participants. Torque and current were recorded during testing with fatiguing trains using each NMES type under isometric and isokinetic (180°/s) conditions. Compared with CONV stimulation, SEQ techniques reduced fatigue-related outcomes, increased potentiation, did not affect variability, and reduced efficiency. SEQ techniques hold promise for reducing fatigue during NMES-based rehabilitation and exercise; however, optimization is required to improve efficiency. Muscle Nerve 56: 271-281, 2017. © 2016 Wiley Periodicals, Inc.

Common neural structures activated by epidural and transcutaneous lumbar spinal cord stimulation: Elicitation of posterior root-muscle reflexes

PubMed Central

Freundl, Brigitta; Binder, Heinrich; Minassian, Karen

2018-01-01

Epidural electrical stimulation of the lumbar spinal cord is currently regaining momentum as a neuromodulation intervention in spinal cord injury (SCI) to modify dysregulated sensorimotor functions and augment residual motor capacity. There is ample evidence that it engages spinal circuits through the electrical stimulation of large-to-medium diameter afferent fibers within lumbar and upper sacral posterior roots. Recent pilot studies suggested that the surface electrode-based method of transcutaneous spinal cord stimulation (SCS) may produce similar neuromodulatory effects as caused by epidural SCS. Neurophysiological and computer modeling studies proposed that this noninvasive technique stimulates posterior-root fibers as well, likely activating similar input structures to the spinal cord as epidural stimulation. Here, we add a yet missing piece of evidence substantiating this assumption. We conducted in-depth analyses and direct comparisons of the electromyographic (EMG) characteristics of short-latency responses in multiple leg muscles to both stimulation techniques derived from ten individuals with SCI each. Post-activation depression of responses evoked by paired pulses applied either epidurally or transcutaneously confirmed the reflex nature of the responses. The muscle responses to both techniques had the same latencies, EMG peak-to-peak amplitudes, and waveforms, except for smaller responses with shorter onset latencies in the triceps surae muscle group and shorter offsets of the responses in the biceps femoris muscle during epidural stimulation. Responses obtained in three subjects tested with both methods at different time points had near-identical waveforms per muscle group as well as same onset latencies. The present results strongly corroborate the activation of common neural input structures to the lumbar spinal cord—predominantly primary afferent fibers within multiple posterior roots—by both techniques and add to unraveling the basic mechanisms underlying electrical SCS. PMID:29381748

Breath detection by transcutaneous electromyography of the diaphragm and the Graseby capsule in preterm infants.

PubMed

de Waal, Cornelia G; Kraaijenga, Juliette V; Hutten, Gerard J; de Jongh, Frans H; van Kaam, Anton H

2017-12-01

To compare triggering, breath detection and delay time of the Graseby capsule (GC) and transcutaneous electromyography of the diaphragm (dEMG) in spontaneous breathing preterm infants. In this observational study, a 30 minutes respiration measurement was conducted by respiratory inductance plethysmography (RIP), the GC, and dEMG in stable preterm infants. Triggering was investigated with an in vitro set-up using the Infant Flow ® SiPAP TM system. The possibility to optimize breath detection was tested by developing new algorithms with the abdominal RIP band (RIP AB ) as gold standard. In a subset of breaths, the delay time was calculated between the inspiratory onset in the RIP AB signal and in the GC and dEMG signal. Fifteen preterm infants with a mean gestational age of 28 ± 2 weeks and a mean birth weight of 1086 ± 317 g were included. In total, 14 773 breaths were analyzed. Based on the GC and dEMG signal, the Infant Flow ® SiPAP™ system, respectively, triggered 67.8% and 62.6% of the breaths. Breath detection was improved to 99.9% for the GC and 113.4% for dEMG in new algorithms. In 1492 stable breaths, the median delay time of inspiratory onset detection was +154 ms (IQR +118 to +164) in the GC and -50 ms (IQR -90 to -22) in the dEMG signal. Breath detection using the GC can be improved by optimizing the algorithm. Transcutaneous dEMG provides similar breath detection but with the advantage of detecting the onset of inspiration earlier than the GC. © 2017 Wiley Periodicals, Inc.

Transcutaneous pulsed radiofrequency treatment for patients with shoulder pain booked for surgery: a double-blind, randomized controlled trial.

PubMed

Taverner, Murray; Loughnan, Terence

2014-02-01

Shoulder pain is the third most common musculoskeletal problem and accounts for 5% of general practitioner consultations. Although many treatments are described, there is no consensus on optimal treatment and up to 40% of patients still have pain 12 months after initially seeking help for pain. Previously, the effect of transcutaneous pulsed radiofrequency treatment (TCPRFT) was evaluated in a retrospective audit that showed good pain relief for a mean 395 days and justified this randomized sham controlled trial. In this study, 51 patients entered into a randomized double-blinded, placebo controlled study of TCPRFT. Patients were assessed at 4 and 12 weeks by a blinded observer and compared with baseline. We observed sustained reductions in pain at night, pain with activity, and functional improvement at 4 and 12 weeks with active but not sham TCPRFT. The 25 subjects who received active treatment showed statistically significant reductions of 24/100 in pain at night and 20/100 of pain with activity at 4 weeks and 18/100 and 19/100, respectively, at 12 weeks from baseline. Statistically significant lower Brief Pain Inventory pain and function scores (4 and 12 weeks), improved pain self-efficacy (4 weeks), Oxford Shoulder scores (12 weeks), and internal rotation (12 weeks) were seen. Pain at both rest and shoulder elevation were not improved by active treatment. No complications were seen. This study of a simple, low risk, outpatient treatment confirms the findings of our earlier study of TCPRFT for knee pain and shoulder pain audit that transcutaneous pulsed radiofrequency treatment may help some people with painful shoulders. © 2013 The Authors Pain Practice © 2013 World Institute of Pain.

MAPs/bFGF-PLGA microsphere composite-coated titanium surfaces promote increased adhesion and proliferation of fibroblasts.

PubMed

Wang, Zhongshan; Wu, Guofeng; Bai, Shizhu; Feng, Zhihong; Dong, Yan; Zhou, Jian; Qin, Haiyan; Zhao, Yimin

2014-06-01

Infection and epithelial downgrowth are two major problems with maxillofacial transcutaneous implants, and both are mainly due to lack of stable closure of soft tissues at transcutaneous sites. Fibroblasts have been shown to play a key role in the formation of biological seals. In this work, titanium (Ti) model surfaces were coated with mussel adhesive proteins (MAPs) utilizing its unique adhesion ability on diverse inorganic and organic surfaces in wet environments. Prepared basic fibroblast growth factor (bFGF)-poly(lactic-co-glycolic acid) (PLGA) microspheres can be easily synthesized and combined onto MAPs-coated Ti surfaces, due to the negative surface charges of microspheres in aqueous solution, which is in contrast to the positive charges of MAPs. Titanium model surfaces were divided into three groups. Group A: MAPs/bFGF-PLGA microspheres composite-coated Ti surfaces. Group B: MAPs-coated Ti surfaces. Group C: uncoated Ti surfaces. The effects of coated Ti surfaces on adhesion of fibroblasts, cytoskeletal organization, proliferation, and extracellular matrix (ECM)-related gene expressions were examined. The results revealed increased adhesion (P < 0.05), enhanced actin cytoskeletal organization, and up-regulated ECM-related gene expressions in groups A and B compared with group C. Increased proliferation of fibroblasts during five days of incubation was observed in group A compared with groups B and C (P < 0.05). Collectively, the results from this in vitro study demonstrated that MAPs/bFGF-PLGA microspheres composite-coated Ti surfaces had the ability to increase fibroblast functionality. In addition, MAPs/bFGF-PLGA microsphere composite-coated Ti surfaces should be studied further as a method of promoting formation of stable biological seals around transcutaneous sites.

Prevalence of sleep apnoea and capnographic detection of nocturnal hypoventilation in amyotrophic lateral sclerosis.

PubMed

Boentert, Matthias; Glatz, Christian; Helmle, Cornelia; Okegwo, Angelika; Young, Peter

2018-04-01

This retrospective study aimed to investigate whether overnight oxymetry and early morning blood gas analysis predict nocturnal hypoventilation (NH) as reflected by night-time hypercapnia in patients with amyotrophic lateral sclerosis (ALS). In addition, prevalence and clinical determinants of sleep apnoea in ALS were evaluated. In 250 patients with non-ventilated ALS, transcutaneous capnometry was performed along with polysomnography or polygraphy and early morning blood gases. 123 patients were female, and 84 patients had bulbar-onset ALS. 40.0% showed NH, and an apnoea-hypopnoea index (AHI) >5/hour was found in 45.6%. In 22.3%, sleep apnoea and NH coincided. The obstructive apnoea index was significantly higher than the central apnoea index (p<0.0001). Both NH and sleep apnoea were significantly more common in male than in female patients. Sleep apnoea and AHI were associated with better bulbar function. Desaturation time (t <90% ) and transcutaneous CO 2 were negatively correlated with upright vital capacity. Early morning base excess (EMBE), bicarbonate and t <90% were independent predictors of NH. However, among 100 patients with NH, 31 were missed by t <90% >5 min and 17 were not identified when EMBE >3 mmol/L and t <90% >5 min were combined. In ALS, sleep apnoea is common and often accompanies NH. It is mainly obstructive, and central apnoea appears to be clinically irrelevant. Polygraphy or oxymetry alone are not sufficient to uncover NH. Combination of EMBE and t <90% may increase sensitivity, but transcutaneous capnography is strongly recommended for reliable detection of NH in patients with ALS. © 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.

A new transcutaneous bidirectional communication for monitoring implanted artificial heart using the human body as a conductive medium.

PubMed

Okamoto, Eiji; Kato, Yoshikuni; Seino, Kazuyuki; Miura, Hidekazu; Shiraishi, Yasuyuki; Yambe, Tomoyuki; Mitamura, Yoshinori

2012-10-01

A transcutaneous communication system (TCS) is a key technology for monitoring and controlling artificial hearts and other artificial organs in the body. In this study, we developed a new TCS that uses the human body as a conductive medium. Direct data exchange provides a higher level of communication security compared to that of wireless methods without physical constraints such as an external wire. The external and internal units of the new TCS each consist mainly of a data transmitter and a data receiver. The data transmitter has an amplitude shift keying (ASK) modulator (carrier frequencies: 4 and 10 MHz) and an electrode. The ASK-modulated data current is led into the body through the electrode, and it flows back to the energy source through the body, the data receiver, and the earth ground that includes all conductors and dielectrics in the environment that are in close proximity to the patient. Performance of the TCS was evaluated by a communication test on the surface of the human body and in an animal experiment using a goat. The TCS was able to transmit data concurrently for 4 weeks between everywhere on the surface of the body and everywhere inside the body under full-duplex communication at a transmission rate of 115 kbps. The power consumption of each TCS unit was 125 mW with an ASK-modulated current of 7 mA (root-mean-square). While further study is required to secure its safety, the newly developed TCS has promise to be a next-generation transcutaneous communication device. © 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Sub-threshold depolarizing pre-pulses can enhance the efficiency of biphasic stimuli in transcutaneous neuromuscular electrical stimulation.

PubMed

Vargas Luna, Jose Luis; Mayr, Winfried; Cortés-Ramirez, Jorge-Armando

2018-06-09

There is multiple evidence in the literature that a sub-threshold pre-pulse, delivered immediately prior to an electrical stimulation pulse, can alter the activation threshold of nerve fibers and motor unit recruitment characteristics. So far, previously published works combined monophasic stimuli with sub-threshold depolarizing pre-pulses (DPPs) with inconsistent findings-in some studies, the DPPs decreased the activation threshold, while in others it was increased. This work aimed to evaluate the effect of DPPs during biphasic transcutaneous electrical stimulation and to study the possible mechanism underlying those differences. Sub-threshold DPPs between 0.5 and 15 ms immediately followed by biphasic or monophasic pulses were administered to the tibial nerve; the electrophysiological muscular responses (motor-wave, M-wave) were monitored via electromyogram (EMG) recording from the soleus muscle. The data show that, under the specific studied conditions, DPPs tend to lower the threshold for nerve fiber activation rather than elevating it. DPPs with the same polarity as the leading phase of biphasic stimuli are more effective to increase the sensitivity. This work assesses for the first time the effect of DPPs on biphasic pulses, which are required to achieve charge-balanced stimulation, and it provides guidance on the effect of polarity and intensity to take full advantage of this feature. Graphical abstract In this work, the effect of sub-threshold depolarizing pre-pulses (DPP) is investigated in a setup with transcutaneous electrical stimulation. We found that, within the tested 0-15 ms DPP duration range, the DPPs administered immediately before biphasic pulses proportionally increase the nerve excitability as visible in the M-waves recorded from the soleus muscle. Interestingly, these findings oppose published results, where DPPs, administered immediately before monophasic stimuli via implanted electrodes, led to decrease of nerve excitability.

Dose postural control improve following application of transcutaneous electrical nerve stimulation in diabetic peripheral neuropathic patients? A randomized placebo control trial.

PubMed

Saadat, Z; Rojhani-Shirazi, Z; Abbasi, L

2017-12-01

peripheral neuropathy is the most common problem of diabetes. Neuropathy leads to lower extremity somatosensory deficits and postural instability in these patients. However, there are not sufficient evidences for improving postural control in these patients. To investigate the effects of transcutaneous electrical nerve stimulation (TENS) on postural control in patients with diabetic neuropathy. Twenty eighth patients with diabetic neuropathy (40-55 Y/O) participated in this RCT study. Fourteen patients in case group received TENS and sham TENS was used for control group. Force plate platform was used to extract sway velocity and COP displacement parameters for postural control evaluation. The mean sway velocity and center of pressure displacement along the mediolateral and anteroposterior axes were not significantly different between two groups after TENS application (p>0.05). Application of 5min high frequency TENS on the knee joint could not improve postural control in patients with diabetic neuropathy. Copyright © 2017. Published by Elsevier Ltd.

Effectiveness of Transcutaneous Electrical Nerve Stimulation for Treatment of Hyperalgesia and Pain

PubMed Central

DeSantana, Josimari M.; Walsh, Deirdre M.; Vance, Carol; Rakel, Barbara A.; Sluka, Kathleen A.

2009-01-01

Transcutaneous electrical nerve stimulation (TENS) is a nonpharmacologic treatment for pain relief. TENS has been used to treat a variety of painful conditions. This review updates the basic and clinical science regarding the use of TENS that has been published in the past 3 years (ie, 2005−2008). Basic science studies using animal models of inflammation show changes in the peripheral nervous system, as well as in the spinal cord and descending inhibitory pathways, in response to TENS. Translational studies show mechanisms to prevent analgesic tolerance to repeated application of TENS. This review also highlights data from recent randomized, placebo-controlled trials and current systematic reviews. Clinical trials suggest that adequate dosing, particularly intensity, is critical to obtaining pain relief with TENS. Thus, evidence continues to emerge from both basic science and clinical trials supporting the use of TENS for the treatment of a variety of painful conditions while identifying strategies to increase TENS effectiveness. PMID:19007541

Development of Novel Faster-Dissolving Microneedle Patches for Transcutaneous Vaccine Delivery

PubMed Central

Ono, Akihiko; Ito, Sayami; Sakagami, Shun; Saito, Mio; Quan, Ying-Shu; Kamiyama, Fumio; Hirobe, Sachiko; Okada, Naoki

2017-01-01

Microneedle (MN) patches are promising for transcutaneous vaccination because they enable vaccine antigens to physically penetrate the stratum corneum via low-invasive skin puncturing, and to be effectively delivered to antigen-presenting cells in the skin. In second-generation MN patches, the dissolving MNs release the loaded vaccine antigen into the skin. To shorten skin application time for clinical practice, this study aims to develop novel faster-dissolving MNs. We designed two types of MNs made from a single thickening agent, carboxymethylcellulose (CMC) or hyaluronan (HN). Both CMC-MN and HN-MN completely dissolved in rat skin after a 5-min application. In pre-clinical studies, both MNs could demonstrably increase antigen-specific IgG levels after vaccination and prolong antigen deposition compared with conventional injections, and deliver antigens into resected human dermal tissue. In clinical research, we demonstrated that both MNs could reliably and safely puncture human skin without any significant skin irritation from transepidermal water loss measurements and ICDRG (International Contact Dermatitis Research Group) evaluation results. PMID:28771172

Myoelectric intuitive control and transcutaneous electrical stimulation of the forearm for vibrotactile sensation feedback applied to a 3D printed prosthetic hand.

PubMed

Germany, Enrique I; Pino, Esteban J; Aqueveque, Pablo E

2016-08-01

This paper presents the development of a myoelectric prosthetic hand based on a 3D printed model. A myoelectric control strategy based on artificial neural networks is implemented on a microcontroller for online position estimation. Position estimation performance achieves a correlation index of 0.78. Also a study involving transcutaneous electrical stimulation was performed to provide tactile feedback. A series of stimulations with controlled parameters were tested on five able-body subjects. A single channel stimulator was used, positioning the electrodes 8 cm on the wrist over the ulnar and median nerve. Controlling stimulation parameters such as intensity, frequency and pulse width, the subjects were capable of distinguishing different sensations over the palm of the hand. Three main sensations where achieved: tickling, pressure and pain. Tickling and pressure were discretized into low, moderate and high according to the magnitude of the feeling. The parameters at which each sensation was obtained are further discussed in this paper.

What makes transcutaneous electrical nerve stimulation work? Making sense of the mixed results in the clinical literature.

PubMed

Sluka, Kathleen A; Bjordal, Jan M; Marchand, Serge; Rakel, Barbara A

2013-10-01

Transcutaneous electrical nerve stimulation (TENS) is a nonpharmacological treatment for control of pain. It has come under much scrutiny lately with the Center for Medicare Services rendering a recent decision stating that "TENS is not reasonable and necessary for the treatment of CLBP [chronic low back pain]." When reading and analyzing the existing literature for which systematic reviews show that TENS is inconclusive or ineffective, it is clear that a number of variables related to TENS application have not been considered. Although many of the trials were designed with the highest of standards, recent evidence suggests that factors related to TENS application need to be considered in an assessment of efficacy. These factors include dosing of TENS, negative interactions with long-term opioid use, the population and outcome assessed, timing of outcome measurement, and comparison groups. The purpose of this perspective is to highlight and interpret recent evidence to help improve the design of clinical trials and the efficacy of TENS in the clinical setting.

Angiotensin-converting Enzyme Inhibition Improves the Effectiveness of Transcutaneous Carbon Dioxide Treatment

PubMed Central

NEMETH, BALAZS; KISS, ISTVAN; JENCSIK, TIMEA; PETER, IVAN; KRESKA, ZITA; KOSZEGI, TAMAS; MISETA, ATTILA; KUSTAN, PETER; BONCZ, IMRE; LACZO, ANDREA; AJTAY, ZENO

2017-01-01

Aim: To study the effect of carbon dioxide (CO2) therapy on the nitric oxide (NO) pathway by monitoring plasma asymmetric dimethylarginine (ADMA) concentrations. Patients and Methods: Forty-seven hypertensive patients who underwent transcutaneous CO2 therapy were enrolled. Thirty healthy individuals were recruited for the control group. Blood samples were taken one hour before, as well as one hour, 24 hours and 3 weeks after the first CO2 treatment. Controls did not undergo CO2 treatment. Plasma ADMA levels were measured by ELISA. Results: ADMA levels decreased significantly one hour after the first CO2 treatment compared to the baseline concentrations (p=0.003). Significantly greater reduction was found among patients in whom angiotensin converting enzyme inhibitors (ACEIs) were administered (p=0.019). Conclusion: The short- and long-term decrease of ADMA levels suggests that CO2 is not only a vasodilator, but also has a beneficial effect on the NO pathway. ACE inhibition seems to enhance the effect of CO2 treatment. PMID:28438873

Late administration of high-frequency electrical stimulation increases nerve regeneration without aggravating neuropathic pain in a nerve crush injury.

PubMed

Su, Hong-Lin; Chiang, Chien-Yi; Lu, Zong-Han; Cheng, Fu-Chou; Chen, Chun-Jung; Sheu, Meei-Ling; Sheehan, Jason; Pan, Hung-Chuan

2018-06-25

High-frequency transcutaneous neuromuscular electrical nerve stimulation (TENS) is currently used for the administration of electrical current in denervated muscle to alleviate muscle atrophy and enhance motor function; however, the time window (i.e. either immediate or delayed) for achieving benefit is still undetermined. In this study, we conducted an intervention of sciatic nerve crush injury using high-frequency TENS at different time points to assess the effect of motor and sensory functional recovery. Animals with left sciatic nerve crush injury received TENS treatment starting immediately after injury or 1 week later at a high frequency(100 Hz) or at a low frequency (2 Hz) as a control. In SFI gait analysis, either immediate or late admission of high-frequency electrical stimulation exerted significant improvement compared to either immediate or late administration of low-frequency electrical stimulation. In an assessment of allodynia, immediate high frequency electrical stimulation caused a significantly decreased pain threshold compared to late high-frequency or low-frequency stimulation at immediate or late time points. Immunohistochemistry staining and western blot analysis of S-100 and NF-200 demonstrated that both immediate and late high frequency electrical stimulation showed a similar effect; however the effect was superior to that achieved with low frequency stimulation. Immediate high frequency electrical stimulation resulted in significant expression of TNF-α and synaptophysin in the dorsal root ganglion, somatosensory cortex, and hippocampus compared to late electrical stimulation, and this trend paralleled the observed effect on somatosensory evoked potential. The CatWalk gait analysis also showed that immediate electrical stimulation led to a significantly high regularity index. In primary dorsal root ganglion cells culture, high-frequency electrical stimulation also exerted a significant increase in expression of TNF-α, synaptophysin, and NGF in accordance with the in vivo results. Immediate or late transcutaneous high-frequency electrical stimulation exhibited the potential to stimulate the motor nerve regeneration. However, immediate electrical stimulation had a predilection to develop neuropathic pain. A delay in TENS initiation appears to be a reasonable approach for nerve repair and provides the appropriate time profile for its clinical application.

Deadly drop--cholinergic syndrome from wearing a laundered uniform.

PubMed

Senthilkumaran, Subramanian; SathyaPrabhu, Krishnanswamy; Balamurugan, Namasivayam; Thirumalaikolundusubramanian, Ponniah

2012-01-01

Unintentional organophosphate compound poisoning, although known, contamination of organophosphate compound through laundered uniform and subsequent transcutaneous absorption, in 30 children is reported herewith for its rarity. Emergency physicians have to recognize such entities clinically, confirm by laboratory means wherever possible, and intervene with appropriate measures.

21 CFR 870.3670 - Pacemaker charger.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pacemaker charger. 870.3670 Section 870.3670 Food... DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3670 Pacemaker charger. (a) Identification. A pacemaker charger is a device used transcutaneously to recharge the batteries of a rechargeable...

21 CFR 870.3670 - Pacemaker charger.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pacemaker charger. 870.3670 Section 870.3670 Food... DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3670 Pacemaker charger. (a) Identification. A pacemaker charger is a device used transcutaneously to recharge the batteries of a rechargeable...

21 CFR 870.3670 - Pacemaker charger.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pacemaker charger. 870.3670 Section 870.3670 Food... DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3670 Pacemaker charger. (a) Identification. A pacemaker charger is a device used transcutaneously to recharge the batteries of a rechargeable...

21 CFR 870.3670 - Pacemaker charger.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pacemaker charger. 870.3670 Section 870.3670 Food... DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3670 Pacemaker charger. (a) Identification. A pacemaker charger is a device used transcutaneously to recharge the batteries of a rechargeable...

The efficacy of transcutaneous electrical nerve stimulation on the improvement of walking distance in patients with peripheral arterial disease with intermittent claudication: study protocol for a randomised controlled trial: the TENS-PAD study.

PubMed

Besnier, Florent; Sénard, Jean-Michel; Grémeaux, Vincent; Riédel, Mélanie; Garrigues, Damien; Guiraud, Thibaut; Labrunée, Marc

2017-08-10

In patients with peripheral arterial disease (PAD), walking improvements are often limited by early pain onset due to vascular claudication. It would thus appear interesting to develop noninvasive therapeutic strategies, such as transcutaneous electrical nerve stimulation (TENS), to improve the participation of PAD patients in rehabilitation programmes, and thus improve their quality of life. Our team recently tested the efficacy of a single 45-min session of 10-Hz TENS prior to walking. TENS significantly delayed pain onset and increased the pain-free walking distance in patients with class-II PAD. We now seek to assess the efficacy of a chronic intervention that includes the daily use of TENS for 3 weeks (5 days a week) on walking distance in Leriche-Fontaine stage-II PAD patients. This is a prospective, double-blind, multicentre, randomised, placebo-controlled trial. One hundred subjects with unilateral PAD (Leriche-Fontaine stage II) will be randomised into two groups (1:1). For the experimental group (TENS group): the treatment will consist of stimulation of the affected leg (at a biphasic frequency of 10 Hz, with a pulse width of 200 μs, maximal intensity below the motor threshold) for 45 min per day, in the morning before the exercise rehabilitation programme, for 3 weeks, 5 days per week. For the control group (SHAM group): the placebo stimulation will be delivered according to the same modalities as for the TENS group but with a voltage level automatically falling to zero after 10 s of stimulation. First outcome: walking distance without pain. transcutaneous oxygen pressure (TcPO 2 ) measured during a Strandness exercise test, peak oxygen uptake (VO 2 peak), endothelial function (EndoPAT®), Ankle-brachial Pressure Index, Body Mass Index, lipid profile (LDL-C, HDL-C, triglycerides), fasting glycaemia, HbA1c level, and the WELCH questionnaire. TENS-PAD is the first randomised controlled trial that uses transcutaneous electrical therapy as an adjuvant technique to improve vascular function in the treatment of PAD. If the results are confirmed, this technique could be incorporated into the routine care in cardiovascular rehabilitation centers and used in the long term by patients to improve their walking capacity. ClinicalTrials.gov, ID: NCT02678403 . Registered on 9 February 2016. Toulouse University Hospital.

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

Use of tens in pain management: part two--how to use tens.

PubMed

Poole, Debbie

Transcutaneous electrical nerve stimulation is widely used in pain management but its effectiveness depends on the stimulation being targeted appropriately. This article, the second in a two-part series, outlines how to set up and use a TENS machine to achieve the most effective results.

[The spa and health resort- based treatment of back pain syndrome in the adolescents presenting with juvenile idiopathic scoliosis].

PubMed

Kravtsova, E Yu; Murav'ev, S V; Kravtsov, Yu I

The relevance of the problem arises from the lack of substantiation for the inclusion of transcutaneous spinal direct current stimulation (tSDCS) in the comprehensive spa and health resort-based treatment of back pain syndrome in the adolescents presenting with juvenile idiopathic scoliosis. The objective of the present study was to demonstrate the effectiveness of transcutaneous spinal direct current stimulation for the comprehensive spa and health resort-based treatment of back pain syndrome in the adolescents presenting with juvenile idiopathic scoliosis. A total of 18 patients with scoliosis forming the study group 1 received the traditional comprehensive spa and health resort-based treatment. The course of transcutaneous spinal direct current stimulation was prescribed to 38 other patients (comprising group 2) in addition to the standard procedures. Another control group was comprised of 15 practically healthy adolescents having no signs of spinal deformations. The visual analog scale for pain, the McGill questionnaire, the scale for the assessment of the situational and personal uneasiness levels (Spilberger Ch.D., Khanin Yu.L.), and the Beck and Tsung depression scales were used, beside the routine clinical methods. Statistical data processing was carried out with the use of the Statistica 6.0 software package. In the group of patients treated with the use of transcutaneous spinal direct current stimulation, regression of pain syndrome was well apparent. In the boys with the severity of pain estimated at 2 points based on the visual analog scale who received the standard course of the spa and health resort-based treatment, the pain rank index and the index of the number of the selected descriptors decreased significantly but nonetheless remained higher than in the patients treated by means of tSDCS as a component of the combined therapy (p=0.039). Simultaneously, the significantly lower level of situational (Q1=25.00; Me=36.50; Q3=45.00; p=0.036) and personal (Q1=26.00; Me=36.50; Q3=44.00; p=0.07) anxiety was observed in the group of girls in comparison with the group of those given only the standard course of the spa and health resort-based treatment. In addition, the level of trait anxiety in the female patients treated with the use of tSDCS was lower than in the girls of the control group (Q1=46.00; Me=49.00; Q3=51.5; p=0.001). In the boys undergoing the course the of tSDCS treatment, the levels of trait anxiety (Q1=29.00 ; Me=37.00 ; Q3=42.00; p=0.021) and depression estimated from the Tsung scale (Q1=2.85; Me=3.00; Q3=3.60; p=0.014) and the cognitive-affective scale of Beck (Q1=0.50; Me=2.00; Q3=5.50; p=0.041) were significantly lower than in the boys of the control group. The level of depression based on the Tsung scale was significantly lower (p=0.020) in the boys and after the standard spa and health resort-based treatment (Q1=2.50; Me=2.90; Q3=3.60) was comparable with that in the boys of the control group (Q1=4.00; Me=4.60; Q3=4.80). The present study has demonstrated the expediency of inclusion of a course of transcutaneous spinal direct current stimulation in the programs of the combined spa and health resort-based treatment for the adolescents presenting with scoliosis.

Analysis of factors controlling sediment phosphorus flux potential of wetlands in Hulun Buir grassland by principal component and path analysis method.

PubMed

He, Jing; Su, Derong; Lv, Shihai; Diao, Zhaoyan; Ye, Shengxing; Zheng, Zhirong

2017-11-08

Phosphorus (P) flux potential can predict the trend of phosphorus release from wetland sediments to water and provide scientific parameters for further monitoring and management for phosphorus flux from wetland sediments to overlying water. Many studies have focused on factors affecting sediment P flux potential in sediment-water interface, but rarely on the relationship among these factors. In the present study, experiment on sediment P flux potential in sediment-water interface was conducted in six wetlands in Hulun Buir grassland, China and the relationships among sediment P flux potential in sediment-water interface, sediment physical properties, and sediment chemical characteristics were examined. Principal component analysis and path analysis were used to discuss these data in correlation coefficient, direct, and indirect effects on sediment P flux potential in sediment-water interface. Results indicated that the major factors affecting sediment P flux potential in sediment-water interface were amount of organophosphate-degradation bacterium in sediment, Ca-P content, and total phosphorus concentrations. The factors of direct influence sediment P flux potential were sediment Ca-P content, Olsen-P content, SOC content, and sediment Al-P content. The indirect influence sediment P flux potential in sediment-water interface was sediment Olsen-P content, sediment SOC content, sediment Ca-P content, and sediment Al-P content. And the standard multiple regression describing the relationship between sediment P flux potential in sediment-water interface and its major effect factors was Y = 5.849 - 1.025X 1  - 1.995X 2  + 0.188X 3  - 0.282X 4 (r = 0.9298, p < 0.01, n = 96), where Y is sediment P flux potential in sediment-water interface, X 1 is sediment Ca-P content, X 2 is sediment Olsen-P content, X 3 is sediment SOC content, and X 4 is sediment Al-P content. Therefore, future research will focus on these sediment properties to analyze the interrelation among sediment properties factors, main vegetable factors, and environment factors which influence the sediment P flux potential in sediment-water interface.

Elastic and piezoelectric fields around a quantum wire of zincblende heterostructures with interface elasticity effect

NASA Astrophysics Data System (ADS)

Ye, Wei; Liu, Yifei

2018-04-01

This work formulates the solutions to the elastic and piezoelectric fields around a quantum wire (QWR) with interface elasticity effect. Closed-form solutions to the piezoelectric potential field of zincblende QWR/matrix heterostructures grown along [111] crystallographic orientation are found and numerical results of InAs/InP heterostructures are provided as an example. The piezoelectric potential in the matrix depends on the interface elasticity, the radius and stiffness of the QWR. Our results indicate that interface elasticity can significantly alter the elastic and piezoelectric fields near the interface. Additionally, when the elastic property of the QWR is considered to be anisotropic in contrary to the common isotropic assumption, piezoelectric potentials are found to be distinct near the interface, but the deviations are negligible at positions far away from the interface.

Microneedles for intradermal and transdermal delivery

PubMed Central

Tuan-Mahmood, Tuan-Mazlelaa; McCrudden, Maeliosa T.C.; Torrisi, Barbara M.; McAlister, Emma; Garland, Martin J; Singh, Thakur Raghu Raj; Donnelly, Ryan F

2014-01-01

The formidable barrier properties of the uppermost layer of the skin, the stratum corneum impose significant limitations for successful systemic delivery of a broad range of therapeutic molecules, particularly macromolecules and genetic material. Microneedle delivery has been proposed as a strategy to breach the SC barrier function in order to facilitate effective transport of molecules across the skin. This strategy involves the use of micron sized needles fabricated from different materials and using different geometries to create transient aqueous conduits across the skin. Microneedles in isolation, or in combination with other enhancing strategies, have been shown to dramatically enhance the skin permeability of numerous therapeutic molecules including biopharmaceuticals either in vitro, ex vivo or in vivo. Progress in the areas of microneedle design, development and manufacture have proven promising in terms of the potential use of this emerging delivery method in clinical applications such as insulin delivery, transcutaneous immunisations and cutaneous gene delivery. This review article focuses on recent and potential future developments in microneedle technologies. This will include the detailing of progress made in microneedle design, an exploration of the challenges faced in this field and potential forward strategies to embrace the exploitation of microneedle methodologies, while considering the inherent safety aspects of such therapeutic tools. PMID:23680534

Nasal continuous positive airway pressure: does bubbling improve gas exchange?

PubMed

Morley, C J; Lau, R; De Paoli, A; Davis, P G

2005-07-01

In a randomised crossover trial, 26 babies, treated with Hudson prong continuous positive airway pressure (CPAP) from a bubbling bottle, received vigorous, high amplitude, or slow bubbling for 30 minutes. Pulse oximetry, transcutaneous carbon dioxide, and respiratory rate were recorded. The bubbling rates had no effect on carbon dioxide, oxygenation, or respiratory rate.

49 CFR 173.137 - Class 8-Assignment of packing group.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the Testing of Chemicals, Number 435, “In Vitro Membrane Barrier Test Method for Skin Corrosion” (IBR... Guideline for the Testing of Chemicals, Number 430, “In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER)” (IBR, see § 171.7 of this subchapter) or Number 431, “In Vitro Skin Corrosion: Human...

Isolated marginal facial nerve paresis after TMJ discopexy: a case report.

PubMed

Reychler, H; Mahy, P

2011-01-01

Isolated marginal facial nerve paresis after TMJ discopexy: a case report. This is the first report of a transient, isolated marginal facial nerve paresis after temporomandibular joint arthrotomy. The paresis seems to have resulted from a crush lesion by Backhaus forceps, placed transcutaneously during the operation to distract the intra-articular space.

Etiological and therapeutical observations in a case of belly dancer's dyskinesia.

PubMed

Linazasoro, Girutz; Van Blercom, Nadège; Lasa, Asier; Fernández, José Manuel; Aranzábal, Inés

2005-02-01

We report on the case of a woman with belly dancer's syndrome. This case presented two peculiarities: (1) the condition was induced by the chronic use of clebopride, and (2) abdominal dyskinesias showed a dramatic response to the application of transcutaneous electrical nerve stimulation. Copyright 2004 Movement Disorder Society.

49 CFR 173.137 - Class 8-Assignment of packing group.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the Testing of Chemicals, Number 435, “In Vitro Membrane Barrier Test Method for Skin Corrosion” (IBR... Guideline for the Testing of Chemicals, Number 430, “In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER)” (IBR, see § 171.7 of this subchapter) or Number 431, “In Vitro Skin Corrosion: Human...

Evaluating efficacy and feasibility of transcutaneous electrical nerve stimulation for postoperative pain after video-assisted thoracoscopic surgery: A randomized pilot trial.

PubMed

Engen, Deborah J; Carns, Paul E; Allen, Mark S; Bauer, Brent A; Loehrer, Laura L; Cha, Stephen S; Chartrand, Christine M; Eggler, Eric J; Cutshall, Susanne M; Wahner-Roedler, Dietlind L

2016-05-01

Transcutaneous electrical nerve stimulation (TENS) has been applied for pain relief after surgical procedures. This study evaluated whether TENS after video-assisted thoracoscopic surgery (VATS), in addition to opioid administration, decreased postoperative pain and pain medication use. In a controlled trial, 56 patients scheduled to undergo VATS were randomly assigned to TENS plus opioids (Group 1) or opioids alone (Group 2) for 48 h. Forty patients completed the study. Pain scores and use of oral morphine equivalents (OMEs) were not significantly different between the groups during the first and second 24 h. A decreased use of OMEs between the first and second 24 h was significant for Group 1 (P = .005) but not for Group 2 (P = .11); a decreased use of OMEs between groups was not significant (P = .35). A larger, well-powered clinical trial is indicated to evaluate the effects of TENS for pain control after a VATS procedure. Clinical Trial No.: NCT01046695. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Transcranial cerebellar direct current stimulation and transcutaneous spinal cord direct current stimulation as innovative tools for neuroscientists

PubMed Central

Priori, Alberto; Ciocca, Matteo; Parazzini, Marta; Vergari, Maurizio; Ferrucci, Roberta

2014-01-01

Two neuromodulatory techniques based on applying direct current (DC) non-invasively through the skin, transcranial cerebellar direct current stimulation (tDCS) and transcutaneous spinal DCS, can induce prolonged functional changes consistent with a direct influence on the human cerebellum and spinal cord. In this article we review the major experimental works on cerebellar tDCS and on spinal tDCS, and their preliminary clinical applications. Cerebellar tDCS modulates cerebellar motor cortical inhibition, gait adaptation, motor behaviour, and cognition (learning, language, memory, attention). Spinal tDCS influences the ascending and descending spinal pathways, and spinal reflex excitability. In the anaesthetised mouse, DC stimulation applied under the skin along the entire spinal cord may affect GABAergic and glutamatergic systems. Preliminary clinical studies in patients with cerebellar disorders, and in animals and patients with spinal cord injuries, have reported beneficial effects. Overall the available data show that cerebellar tDCS and spinal tDCS are two novel approaches for inducing prolonged functional changes and neuroplasticity in the human cerebellum and spinal cord, and both are new tools for experimental and clinical neuroscientists. PMID:24907311

What Makes Transcutaneous Electrical Nerve Stimulation Work? Making Sense of the Mixed Results in the Clinical Literature

PubMed Central

Bjordal, Jan M.; Marchand, Serge; Rakel, Barbara A.

2013-01-01

Transcutaneous electrical nerve stimulation (TENS) is a nonpharmacological treatment for control of pain. It has come under much scrutiny lately with the Center for Medicare Services rendering a recent decision stating that “TENS is not reasonable and necessary for the treatment of CLBP [chronic low back pain].” When reading and analyzing the existing literature for which systematic reviews show that TENS is inconclusive or ineffective, it is clear that a number of variables related to TENS application have not been considered. Although many of the trials were designed with the highest of standards, recent evidence suggests that factors related to TENS application need to be considered in an assessment of efficacy. These factors include dosing of TENS, negative interactions with long-term opioid use, the population and outcome assessed, timing of outcome measurement, and comparison groups. The purpose of this perspective is to highlight and interpret recent evidence to help improve the design of clinical trials and the efficacy of TENS in the clinical setting. PMID:23641031

A low-invasive and effective transcutaneous immunization system using a novel dissolving microneedle array for soluble and particulate antigens.

PubMed

Matsuo, Kazuhiko; Yokota, Yayoi; Zhai, You; Quan, Ying-Shu; Kamiyama, Fumio; Mukai, Yohei; Okada, Naoki; Nakagawa, Shinsaku

2012-07-10

Transcutaneous immunization (TCI) is a promising needle-free, easy-to-use, and low-invasive vaccination method. The hydrogel patch-based TCI system induced immune responses against soluble antigens (Ags) like toxoids, but could not induce immune responses against particulate Ags. Here, as an effective TCI system against every form of Ag, we developed a dissolving microneedle array of three lengths (200, 300, or 800 μm) made of hyaluronate as a novel TCI device. Unlike conventional microneedles, the microneedles of our dissolving microneedle arrays dissolved in the skin after insertion. Each dissolving microneedle array effectively delivered both soluble and particulate Ags under the stratum corneum. TCI using these dissolving microneedle arrays induced effective immune responses in rats regardless of the Ag form that were comparable to conventional vaccination using subcutaneous immunization. In addition, application of these dissolving microneedle arrays caused only slight skin irritation. These findings suggest that our TCI system can simply, safely, and effectively improve protective immune responses for every vaccine Ag. Copyright © 2012 Elsevier B.V. All rights reserved.

Transcutaneous supraorbital neurostimulation for the prevention of chronic migraine: a prospective, open-label preliminary trial.

PubMed

Di Fiore, Paola; Bussone, Gennaro; Galli, Alberto; Didier, Henri; Peccarisi, Cesare; D'Amico, Domenico; Frediani, Fabio

2017-05-01

Since chronic migraine is difficult to treat and often associated with medication overuse, non-invasive neurostimulation approaches are worth investigating. Transcutaneous supraorbital neurostimulation using the Cefaly ® device is promising as a non-invasive preventive treatment for episodic migraine, but no data are available for chronic migraine. Our aim was to perform a preliminary evaluation of the efficacy of the Cefaly ® device for the prophylaxis of chronic migraine with or without medication overuse. Primary endpoints were 50% reduction in monthly migraine days and 50% reduction in monthly medication use over 4 months. In an open-label study, twenty-three consecutive headache center patients with chronic migraine, diagnosed according to International Headache Society criteria, were recruited prospectively. After informed consent, patients were trained to use Cefaly ® and instructed to use it for 20 min daily over 4 months. All patients received active neurostimulation. Thirty-five percent of the patients enrolled in the study achieved the study endpoints. Over half the patients had a greater than 50% reduction in acute medication consumption.

Measurements of glucose on the skin surface, in stratum corneum and in transcutaneous extracts: implications for physiological sampling.

PubMed

Cunningham, David D; Young, Douglas F

2003-09-01

Obtaining representative physiological samples for glucose analysis remains a challenge especially when developing less invasive glucose monitoring systems for diabetic patients. In the present study the glucose content of the stratum corneum was compared with the amount of glucose obtained by short aqueous extractions from a site on the dorsal wrist, using high pressure liquid chromatography with pulsed amperometric detection. Ten successive aqueous 1-minute extractions of the site yielded a total of 60 ng cm(-2). The total glucose content of the stratum corneum of the site, determined from 30 successive tape-strippings of the site, was 360 ng cm(-2). After tape-stripping, the transcutaneous aqueous extraction rate was 86 +/- 13 ng cm(-2) min(-1), compared with rates of 80-600 ng cm(-2) min(-1) obtained with suction effusion or microdialysis after tape-stripping. Glucose on the surface of the skin and within the stratum corneum should be considered as sources of extraneous glucose contamination during testing of less invasive glucose monitoring devices.

Topical dissolved oxygen penetrates skin: model and method.

PubMed

Roe, David F; Gibbins, Bruce L; Ladizinsky, Daniel A

2010-03-01

It has been commonly perceived that skin receives its oxygen supply from the internal circulation. However, recent investigations have shown that a significant amount of oxygen may enter skin from the external overlying surface. A method has been developed for measuring the transcutaneous penetration of human skin by oxygen as described herein. This method was used to determine both the depth and magnitude of penetration of skin by topically applied oxygen. An apparatus consisting of human skin samples interposed between a topical oxygen source and a fluid filled chamber that registered changes in dissolved oxygen. Viable human skin samples of variable thicknesses with and without epidermis were used to evaluate the depth and magnitude of oxygen penetration from either topical dissolved oxygen (TDO) or topical gaseous oxygen (TGO) devices. This model effectively demonstrates transcutaneous penetration of topically applied oxygen. Topically applied dissolved oxygen penetrates through >700 microm of human skin. Topically applied oxygen penetrates better though dermis than epidermis, and TDO devices deliver oxygen more effectively than TGO devices. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Investigation of spatial resolution dependent variability in transcutaneous oxygen saturation using point spectroscopy system

NASA Astrophysics Data System (ADS)

Philimon, Sheena P.; Huong, Audrey K. C.; Ngu, Xavier T. I.

2017-08-01

This paper aims to investigate the variation in one’s percent mean transcutaneous oxygen saturation (StO2) with differences in spatial resolution of data. This work required the knowledge of extinction coefficient of hemoglobin derivatives in the wavelength range of 520 - 600 nm to solve for the StO2 value via an iterative fitting procedure. A pilot study was conducted on three healthy subjects with spectroscopic data collected from their right index finger at different arbitrarily selected distances. The StO2 value estimated by Extended Modified Lambert Beer (EMLB) model revealed a higher mean StO2 of 91.1 ± 1.3% at a proximity distance of 30 mm compared to 60.83 ± 2.8% at 200 mm. The results showed a high correlation between data spatial resolution and StO2 value, and revealed a decrease in StO2 value as the sampling distance increased. The preliminary findings from this study contribute to the knowledge of the appropriate distance range for consistent and high repeatability measurement of skin oxygenation.

Treatment of neuropathic pain in a patient with diabetic neuropathy using transcutaneous electrical nerve stimulation applied to the skin of the lumbar region.

PubMed

Somers, D L; Somers, M F

1999-08-01

Diabetic neuropathy can produce severe pain. The purpose of this case report is to describe the alteration of pain in a patient with severe, painful diabetic neuropathy following application of transcutaneous electrical nerve stimulation (TENS) to the low back. The patient was a 73-year-old woman with pain in the left lower extremity over the lateral aspect of the hip and the entire leg below the knee. The pain prevented sound sleep. The intensity of pain was assessed with a visual analog scale. The TENS (80 Hz) was delivered 1 to 2 hours a day and during the entire night through electrodes placed on the lumbar area of the back. Following 20 minutes of TENS on the first day of treatment, the patient reported a 38% reduction in intensity of pain. After 17 days, the patient reported no pain following 20 minutes of TENS and that she could sleep through the night. Application of TENS to the skin of the lumbar area may be an effective treatment for the pain of diabetic neuropathy.

Effect of Transcutaneous Acupoint Electrical Stimulation on Post-Hemorrhoidectomy-Associated Pain, Anxiety, and Heart Rate Variability: A Randomized-Controlled Study.

PubMed

Yeh, Mei-Ling; Chung, Yu-Chu; Hsu, Lun-Chia; Hung, Shuo-Hui

2018-05-01

Hemorrhoidectomy is the current best treatment for severe hemorrhoids, but it causes significant postoperative pain and anxiety, which is associated with heart rate variability (HRV). Transcutaneous acupoint electrical stimulation (TAES) was assumed to alleviate pain and anxiety, and modify the autonomic nervous system. This study aimed to examine the effects of TAES intervention on postoperative pain, anxiety, and HRV in patients who received a hemorrhoidectomy. A randomized-controlled trial with five repeated measures was conducted. The TAES group ( n = 39) received four 20-min sessions of electrical stimulation at chengshan (BL57) and erbai (EX-UE2) after hemorrhoidectomy, whereas the control group ( n = 41) did not. Data were collected using Visual Analogue Scale (VAS), State Anxiety Inventory (STAI), and HRV physiological signal monitor. TAES resulted in a significant group difference in pain scores, anxiety levels, and some HRV parameters. The findings indicate that TAES can help reduce pain and anxiety associated with hemorrhoidectomy. TAES is a noninvasive, simple, and convenient modality for post-hemorrhoidectomy-associated pain control and anxiety reduction.

Edema and elasticity of a fronto-temporal decompressive craniectomy

PubMed Central

Takada, Daikei; Nagai, Hidemasa; Moritake, Kouzo; Akiyama, Yasuhiko

2012-01-01

Background: Decompressive craniectomy is undertaken for relief of brain herniation caused by acute brain swelling. Brain stiffness can be estimated by palpating the decompressive cranial defect and can provide some relatively subjective information to the neurosurgeon to help guide care. The goal of the present study was to objectively evaluate transcutaneous stiffness of the cranial defect using a tactile resonance sensor and to describe the values in patients with a decompressive window in order to characterize the clinical association between brain edema and stiffness. Methods: Data were prospectively collected from 13 of 37 patients who underwent a decompressive craniectomy in our hospital during a 5-year period. Transcutaneous stiffness was measured as change in frequency and as elastic modulus. Results: Stiffness variables of the decompressive site were measured without any adverse effect and subsequent calculations revealed change in frequency = 101.71 ± 36.42 Hz, and shear elastic modulus = 1.99 ± 1.11 kPa. Conclusions: The elasticity of stiffness of a decompressive site correlated with brain edema, cisternal cerebrospinal fluid pressure, and brain shift, all of which are related to acute brain edema. PMID:22347679

Doubly labeled water method: in vivo oxygen and hydrogen isotope fractionation

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

Schoeller, D.A.; Leitch, C.A.; Brown, C.

The accuracy and precision of the doubly labeled water method for measuring energy expenditure are influenced by isotope fractionation during evaporative water loss and CO/sub 2/ excretion. To characterize in vivo isotope fractionation, we collected and isotopically analyzed physiological fluids and gases. Breath and transcutaneous water vapor were isotopically fractionated. The degree of fractionation indicated that the former was fractionated under equilibrium control at 37/sup 0/C, and the latter was kinetically fractionated. Sweat and urine were unfractionated. By use of isotopic balance models, the fraction of water lost via fractionating routes was estimated from the isotopic abundances of body water,more » local drinking water, and dietary solids. Fractionated water loss averaged 23% (SD = 10%) of water turnover, which agreed with our previous estimates based on metabolic rate, but there was a systematic difference between the results based on O/sub 2/ and hydrogen. Corrections for isotopic fractionation of water lost in breath and (nonsweat) transcutaneous loss should be made when using labeled water to measure water turnover or CO/sub 2/ production.« less

Laser Doppler Flowmetry and Transcutaneous Oximetry in Chronic Skin Ulcers: A Comparative Evaluation.

PubMed

Raposio, Edoardo; Bertozzi, Nicolò; Moretti, Rebecca; Grignaffini, Eugenio; Grieco, Michele P

2017-07-01

Laser Doppler Flowmetry (LDF) and transcutaneous oximetry (TcpO2) are established methods for investigating cutaneous perfusion. To date, no study previously performed has compared data obtained from these 2 methodologies in cases of chronic cutaneous ulcers. Laser Doppler Flowmetry and TcpO2 were performed in 25 consecutive outpatients with chronic lower limb ulcers (group A, experimental; 9 women and 16 men; mean age 67 years [range, 52-81 years]) and 25 age- and sex-matched healthy control subjects (group B, control) enrolled for the study. Ulcer aetiologies included 12 peripheral arterial occlusive disease, 9 chronic venous insufficiencies, and 4 pressure ulcers. Data were analyzed with Shapiro-Wilk and Wilcoxon-Mann-Whitney tests. A statistically significant difference (P < .05) was found between LDF values of the 2 groups. No statistically significant differences were found between the 2 groups regarding the TcpO2 measurements. The data confirmed the soundness of LDF while investigating local perfusion in patients with chronic cutaneous ulcers. The same diagnostic accuracy was not obtained by means of TcpO2.

Dynamic Visualization of Dendritic Cell-Antigen Interactions in the Skin Following Transcutaneous Immunization

PubMed Central

Rattanapak, Teerawan; Birchall, James C.; Young, Katherine; Kubo, Atsuko; Fujimori, Sayumi; Ishii, Masaru; Hook, Sarah

2014-01-01

Delivery of vaccines into the skin provides many advantages over traditional parenteral vaccination and is a promising approach due to the abundance of antigen presenting cells (APC) residing in the skin including Langerhans cells (LC) and dermal dendritic cells (DDC). However, the main obstacle for transcutaneous immunization (TCI) is the effective delivery of the vaccine through the stratum corneum (SC) barrier to the APC in the deeper skin layers. This study therefore utilized microneedles (MN) and a lipid-based colloidal delivery system (cubosomes) as a synergistic approach for the delivery of vaccines to APC in the skin. The process of vaccine uptake and recruitment by specific types of skin APC was investigated in real-time over 4 hours in B6.Cg-Tg (Itgax-EYFP) 1 Mnz/J mice by two-photon microscopy. Incorporation of the vaccine into a particulate delivery system and the use of MN preferentially increased vaccine antigen uptake by a highly motile subpopulation of skin APC known as CD207+ DC. No uptake of antigen or any response to immunisation by LC could be detected. PMID:24586830

Angiotensin-converting Enzyme Inhibition Improves the Effectiveness of Transcutaneous Carbon Dioxide Treatment.

PubMed

Nemeth, Balazs; Kiss, Istvan; Jencsik, Timea; Peter, Ivan; Kreska, Zita; Koszegi, Tamas; Miseta, Attila; Kustan, Peter; Boncz, Imre; Laczo, Andrea; Ajtay, Zeno

2017-01-01

To study the effect of carbon dioxide (CO 2 ) therapy on the nitric oxide (NO) pathway by monitoring plasma asymmetric dimethylarginine (ADMA) concentrations. Forty-seven hypertensive patients who underwent transcutaneous CO 2 therapy were enrolled. Thirty healthy individuals were recruited for the control group. Blood samples were taken one hour before, as well as one hour, 24 hours and 3 weeks after the first CO 2 treatment. Controls did not undergo CO 2 treatment. Plasma ADMA levels were measured by ELISA. ADMA levels decreased significantly one hour after the first CO2 treatment compared to the baseline concentrations (p=0.003). Significantly greater reduction was found among patients in whom angiotensin converting enzyme inhibitors (ACEIs) were administered (p=0.019). The short- and long-term decrease of ADMA levels suggests that CO 2 is not only a vasodilator, but also has a beneficial effect on the NO pathway. ACE inhibition seems to enhance the effect of CO 2 treatment. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

[Comparative study on effects of manipulation treatment and transcutaneous electrical nerve stimulation on patients with cervicogenic headache].

PubMed

Li, Chen; Zhang, Xiu-ling; Ding, Hong; Tao, Yue-qiang; Zhan, Hong-sheng

2007-07-01

To compare the effects of manipulation treatment and transcutaneous electrical nerve stimulation (TENS) on patients with cervicogenic headache. Seventy patients with cervicogenic headache were randomly allocated to receive manipulation treatment and TENS treatment, which were given every other day respectively for total 40 days. The headache degree (numeric rating scale, NRS), frequency, lasting time and the range of motion (ROM) of the cervical spine 2 weeks before treatment and 4 weeks after treatment, were compared. Before treatment, there were no significant differences in the headache NRS scores , frequency, lasting time and the ROM scores between the two groups (P>0.05). After treatment, the headache NRS score, frequency, lasting time in the manipulation group decreased significantly (P<0.01), while in the TENS group just the headache NRS score decreased significantly (P<0.05). The ROM scores in both groups showed no significant changes (P>0.05). The response rate of manipulation treatment is 94.5%, significantly higher than 64.5% of TENS treatment (P<0.05). The manipulation treatment is an effective method for patients with cervicogenic headache.

Effects of short and prolonged transcutaneous vagus nerve stimulation on heart rate variability in healthy subjects.

PubMed

De Couck, M; Cserjesi, R; Caers, R; Zijlstra, W P; Widjaja, D; Wolf, N; Luminet, O; Ellrich, J; Gidron, Y

2017-03-01

The vagus nerve is strategically located in the body, and has multiple homeostatic and health-promoting effects. Low vagal activity predicts onset and progression of diseases. These are the reasons to activate this nerve. This study examined the effects of transcutaneous vagus nerve stimulation (t-VNS) on a main index of vagal activity, namely heart rate variability (HRV). In Study 1, we compared short (10min) left versus right ear t-VNS versus sham (no stimulation) in a within-subjects experimental design. Results revealed significant increases in only one HRV parameter (standard deviation of the RR intervals (SDNN)) following right-ear t-VNS. Study 2 examined the prolonged effects of t-VNS (1h) in the right ear. Compared to baseline, right-t-VNS significantly increased the LF and LF/HF components of HRV, and SDNN in women, but not in men. These results show limited effects of t-VNS on HRV, and are discussed in light of neuroanatomical and statistical considerations and future directions are proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

Implementation of a transcutaneous charger for fully implantable middle ear hearing device.

PubMed

Lim, H; Yoon, Y; Lee, C; Park, I; Song, B; Cho, J

2005-01-01

A transcutaneous charger for the fully implantable middle ear hearing device (F-IMEHD), which can monitor the charging level of battery, has been designed and implemented. In order to recharge the battery of F-IMEHD, the electromagnetic coupling between primary coil at outer body and secondary coil at inner body has been used. Considering the implant condition of the F-IMEHD, the primary coil and the secondary coil have been designed. Using the resonance of LC tank circuit at each coil, transmission efficiency was increased. Since the primary and the secondary coil are magnetically coupled, the current variation of the primary coil is related with the impedance of internal resonant circuit. Using the principle mentioned above, the implanted module could transmit outward the information about charging state of battery or coupling between two coils by the changing internal impedance. As in the demonstrated results of experiment, the implemented charger has supplied the sufficient operating voltage for the implanted battery within about 10 mm distance. And also, it has been confirmed that the implanted module can transmit information outward by control of internal impedance.

Noninvasive lifting of arm, thigh, and knee skin with transcutaneous intense focused ultrasound.

PubMed

Alster, Tina S; Tanzi, Elizabeth L

2012-05-01

Transcutaneous intense focused ultrasound is a novel Food and Drug Administration-approved technology for noninvasive skin tightening of the face and neck. No studies have reported on its safety and effectiveness on nonfacial areas. Eighteen paired areas (6 each) on the upper arms, medial thighs, and extensor knees were randomly treated with two different transducers (4.0 MHz, 4.5-mm focal depth and 7.0 MHz, 3.0-mm focal depth). One side was randomly assigned to receive a single pass (single plane) of microthermal coagulation zones over the involved area with the 4.0 MHz, 4.5-mm-depth transducer, and the contralateral side was assigned to receive consecutive single passes (dual plane) using both transducers (4.0 MHz, 4.5-mm depth followed by 7.0 MHz, 3.0-mm depth). Two independent masked assessors determined clinical improvement scores using comparative standardized photographs obtained at baseline and 3 and 6 months after treatment. Subjective assessments of clinical improvement and side effects of treatment were obtained. Global assessment scores revealed significant improvement in all treated areas, with the upper arms and knees demonstrating more skin lifting and tightening than the thighs. Areas receiving dual-plane treatment had slightly better clinical scores than those receiving single-plane treatment in all three sites. Clinical scores from single-plane and dual-plane treated areas continued to improve between 3 and 6 months after treatment. Side effects were mild and transient and included erythema, warmth, and skin tenderness. Rare focal bruising was noted in two patients on the upper arms that resolved within 7 days. No other side effects were reported or observed. Transcutaneous intense focused ultrasound can be safely and effectively used to improve the clinical appearance (texture and contour) of the upper arms, extensor knees, and medial thighs. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Transcutaneous Nerve Stimulation for Pain Relief During Office Hysteroscopy: A Randomized Controlled Trial.

PubMed

Lisón, Juan F; Amer-Cuenca, Juan J; Piquer-Martí, Silvia; Benavent-Caballer, Vicente; Biviá-Roig, Gemma; Marín-Buck, Alejandro

2017-02-01

To evaluate the pain-relieving effect of transcutaneous electrical nerve stimulation (TENS) during office-based hysteroscopy without sedation. We conducted a randomized, double-blind, placebo-controlled trial. Participants were randomly assigned to the active TENS, placebo TENS, or control group. The active TENS intervention consisted of a varying high-frequency (80-100 Hz), 400-microseconds, individually adjusted, high-intensity TENS application with two self-adhesive electrodes placed parallel to the spinal cord at the T10-L1 and S2-S4 levels. In the placebo group, participants were connected to the TENS unit but delivering no electrical stimulation. The primary outcome was self-reported pain intensity (0-100 mm) measured on a visual analog scale at several stages (entry, contact, biopsy, and residual). The minimum clinically relevant difference for the visual analog scale has been previously reported as 10 mm. Sample size was calculated to provide 80% power to show a 10-mm difference (α=0.0125) in the primary outcome. Secondary outcomes included duration of the procedure, vital parameters, vasovagal symptoms, and participant satisfaction index (0-10 rating scale). A total of 138 women (46 per group) participated in the study between January 2016 and April 2016. No differences were found between groups regarding age, weight, body mass index, parity status, menopausal status, or previous hysteroscopy status. Visual analog scale scores highlighted a decrease in pain in the active TENS group compared with the placebo group (entry: -11 mm, 95% confidence interval [CI] -17 to -5; contact: -21.9 mm, 95% CI -30 to -13.9; biopsy: -30.5 mm, 95% CI -47.1 to -13.8, P<.001). Moreover, the reduction in pain reached the minimum clinically relevant difference. Regarding satisfaction, results also revealed differences between active TENS and placebo groups (1.3, 95% CI 0.5-2.2, P=.001). Transcutaneous electrical nerve stimulation reduces pain and increases patient satisfaction during office hysteroscopy without sedation. ClinicalTrials.gov, www.clinicaltrials.gov, NCT02647008.

Transcutaneous oximetry: normal values for the lower limb.

PubMed

Blake, Denise F; Young, Derelle A; Brown, Lawrence H

2014-09-01

Current guidelines for transcutaneous oximetry measurement (TCOM) for the lower limb define tissue hypoxia as a transcutaneous oxygen partial pressure < 40 mmHg. Values obtained with some newer machines and current research bring these reference values into question. To determine 'normal' TCOM values for the lower limb in healthy, non-smoking adults using the TCM400 oximeter with tc Sensor E5250. Thirty-two healthy, non-smoking volunteers had TCOM performed at six positions on the lower leg and foot. Measurements were taken with subjects lying supine breathing air, then with leg elevated and whilst breathing 100 % oxygen. Room-air TCOM values (mean mmHg, 95 % confidence interval (CI) ) were: lateral leg 41.3, CI 37.8 to 44.7; lateral malleolus 38.6, CI 34.1 to 43.1; medial malleolus 43.9, CI 40.2 to 47.6; dorsum, between first and second toe 39.3, CI 35.9 to 42.7; dorsum, proximal to fifth metatarsal-phalangeal joint 46.4, CI 43.4 to 49.3; plantar 52.3, CI 49.6 to 55.1. Using the currently accepted value of less than 40 mmHg for tissue hypoxia, 24 of our 32 'healthy' subjects had at least one air sensor reading that would have been classified as hypoxic. Seventeen subjects had TCOM values less than 100 mmHg when breathing 100 % normobaric oxygen. Normal lower limb TCOM readings using the TCOM400 with tc Sensor E5250 may be lower than 40 mmHg, used to define tissue hypoxia, but consistent with the wide range of values found in the literature. Because of the wide variability in TCOM at the different sensor sites we cannot recommend one TCOM value as indicative of tissue hypoxia. A thorough clinical assessment of the patient is essential to establish appropriateness for hyperbaric oxygen treatment, with TCOM used as an aid to help guide this decision, but not as an absolute diagnostic tool.

Transcutaneous oxygen pressure measurement in diabetic foot ulcers: mean values and cut-point for wound healing.

PubMed

Yang, Chuan; Weng, Huan; Chen, Lihong; Yang, Haiyun; Luo, Guangming; Mai, Lifang; Jin, Guoshu; Yan, Li

2013-01-01

The purpose of this study was to investigate mean values and cut-point of transcutaneous oxygen pressure (TcPO2) measurement in patients with diabetic foot ulcers. Prospective, descriptive study. Sixty-one patients with diabetes mellitus and foot ulcers comprised the sample. The research setting was Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Participants underwent transcutaneous oxygen (TcPO2) measurement at the dorsum of foot. Patients were classified into 3 groups according to clinical outcomes: (1) ulcers healed with intact skin group, (2) ulcer improved, and (3) ulcer failed to improve. TcPO2 was assessed and cut-points for predicting diabetic foot ulcer healing were calculated. Thirty-six patients healed with intact skin, 8 experienced improvement, and 17 showed no improvement. Mean TcPO2 levels were significantly higher (P< .001) in healed ulcers with intact skin (32 ± 10 mmHg) when compared to the improvement group (30 ± 7 mmHg) and the nonhealing group (15 ± 12 mmHg). All patients with TcPO2≤ 10 mmHg failed to heal or experienced deterioration in their foot ulcers. In contrast, all patients with TcPO2≥ 40 mmHg achieved wound closure. Measurement of TcPO2 in the supine position revealed a cut-point value of 25 mmHg as the best threshold for predicting diabetic foot ulcer healing; the area under the curve using this cut-point was 0.838 (95% confidence interval = 0.700-0.976). The sensitivity, specificity, positive predictive value, and negative predictive value for TxPO2 were 88.6%, 82.4%, 90.7%, and 72.2%, respectively. TcPO2≥ 40 mmHg was associated with diabetic foot ulcer healing, but a TcPO2≤ 10 mmHg was associated with failure of wound healing. We found that a cut-point of 25 mmHg was most predictive of diabetic foot ulcer healing.

The efficiency of CO2 elimination during high-frequency jet ventilation for laryngeal microsurgery.

PubMed

Biro, P; Eyrich, G; Rohling, R G

1998-07-01

For adequate and safe use of high-frequency jet ventilation (HFJV), reliable monitoring of the PCO2 status and course is necessary. Because of improved handling and performance, recently available transcutaneous PCO2 monitoring devices such as MicroGas 7650 (Kontron Instruments Medical Sensors, Basel, Switzerland) should enable more effective surveillance of CO2 elimination and, subsequently, better control of subglottic HFJV. Adult patients (n = 164) undergoing laryngeal microsurgery during total i.v. anesthesia were assessed. The resulting transcutaneous PCO2 values, as well as the necessary driving pressure settings, were analyzed to define the CO2 elimination capacity of each patient. Therefore, an individual CO2 elimination coefficient (ECCO2) was calculated. The frequency distribution of the obtained ECCO2 values showed a normal distribution with a median at 0.79 and a range between 0.30 and 2.17. A significant difference in the frequency of obstructive lung disease was found between two patient subpopulations separated by the 25th percentile at an ECCO2 value of 0.63. Other co-factors of CO2 elimination during HFJV were age, gender, and body weight, whereas height and ventilation duration were not involved. We conclude that the individual assessment of ECCO2 enables one to find adequate ventilator settings, resulting in lower airway pressure and less cooling and drying of the tracheobronchial mucosa. CO2 elimination during high-frequency jet ventilation can be assessed by calculating the CO2 elimination coefficient (ECCO2) of each patient from the required driving pressure and the resulting transcutaneous CO2 partial pressure. The frequency distribution of ECCO2 in a typical laryngological patient population was analyzed, and a value of 0.63 was found to be a characteristic limit between sufficient and difficult CO2 elimination. The individual assessment of ECCO2 enables one to find adequate ventilator settings, resulting in lower airway pressure and less cooling and drying of the tracheobronchial mucosa.

Body Position Influences Which Neural Structures Are Recruited by Lumbar Transcutaneous Spinal Cord Stimulation

PubMed Central

Danner, Simon M.; Krenn, Matthias; Hofstoetter, Ursula S.; Toth, Andrea; Mayr, Winfried; Minassian, Karen

2016-01-01

Transcutaneous stimulation of the human lumbosacral spinal cord is used to evoke spinal reflexes and to neuromodulate altered sensorimotor function following spinal cord injury. Both applications require the reliable stimulation of afferent posterior root fibers. Yet under certain circumstances, efferent anterior root fibers can be co-activated. We hypothesized that body position influences the preferential stimulation of sensory or motor fibers. Stimulus-triggered responses to transcutaneous spinal cord stimulation were recorded using surface-electromyography from quadriceps, hamstrings, tibialis anterior, and triceps surae muscles in 10 individuals with intact nervous systems in the supine, standing and prone positions. Single and paired (30-ms inter-stimulus intervals) biphasic stimulation pulses were applied through surface electrodes placed on the skin between the T11 and T12 inter-spinous processes referenced to electrodes on the abdomen. The paired stimulation was applied to evaluate the origin of the evoked electromyographic response; trans-synaptic responses would be suppressed whereas direct efferent responses would almost retain their amplitude. We found that responses to the second stimulus were decreased to 14%±5% of the amplitude of the response to the initial pulse in the supine position across muscles, to 30%±5% in the standing, and to only 80%±5% in the prone position. Response thresholds were lowest during standing and highest in the prone position and response amplitudes were largest in the supine and smallest in the prone position. The responses obtained in the supine and standing positions likely resulted from selective stimulation of sensory fibers while concomitant motor-fiber stimulation occurred in the prone position. We assume that changes of root-fiber paths within the generated electric field when in the prone position increase the stimulation thresholds of posterior above those of anterior root fibers. Thus, we recommend conducting spinal reflex or neuromodulation studies with subjects lying supine or in an upright position, as in standing or stepping. PMID:26797502

Optimal clinical time for reliable measurement of transcutaneous CO2 with ear probes: counterbalancing overshoot and the vasodilatation effect.

PubMed

Domingo, Christian; Canturri, Elisa; Moreno, Amalia; Espuelas, Humildad; Vigil, Laura; Luján, Manel

2010-01-01

To determine the optimal clinical reading time for the transcutaneous measurement of oxygen saturation (SpO(2)) and transcutaneous CO(2) (TcPCO(2)) in awake spontaneously breathing individuals, considering the overshoot phenomenon (transient overestimation of arterial PaCO(2)). EXPERIMENTAL SECTION: Observational study of 91 (75 men) individuals undergoing forced spirometry, measurement of SpO(2) and TcPCO(2) with the SenTec monitor every two minutes until minute 20 and arterial blood gas (ABG) analysis. Overshoot severity: (a) mild (0.1-1.9 mm Hg); (b) moderate (2-4.9 mm Hg); (c) severe: (>5 mm Hg). The mean difference was calculated for SpO(2) and TcPCO(2) and arterial values of PaCO(2) and SpO(2). The intraclass correlation coefficient (ICC) between monitor readings and blood values was calculated as a measure of agreement. The mean age was 63.1 ± 11.8 years. Spirometric values: FVC: 75.4 ± 6.2%; FEV(1): 72.9 ± 23.9%; FEV(1)/FVC: 70 ± 15.5%. ABG: PaO(2): 82.6 ± 13.2; PaCO(2): 39.9.1 ± 4.8 mmHg; SaO(2): 95.3 ± 4.4%. Overshoot analysis: overshoot was mild in 33 (36.3%) patients, moderate in 20 (22%) and severe in nine (10%); no overshoot was observed in 29 (31%) patients. The lowest mean differences between arterial blood gas and TcPCO(2) was -0.57 mmHg at minute 10, although the highest ICC was obtained at minutes 12 and 14 (>0.8). The overshoot lost its influence after minute 12. For SpO(2), measurements were reliable at minute 2. The optimal clinical reading measurement recommended for the ear lobe TcPCO(2) measurement ranges between minute 12 and 14. The SpO(2) measurement can be performed at minute 2.

Optimal Clinical Time for Reliable Measurement of Transcutaneous CO2 with Ear Probes: Counterbalancing Overshoot and the Vasodilatation Effect

PubMed Central

Domingo, Christian; Canturri, Elisa; Moreno, Amalia; Espuelas, Humildad; Vigil, Laura; Luján, Manel

2010-01-01

OBJECTIVES: To determine the optimal clinical reading time for the transcutaneous measurement of oxygen saturation (SpO2) and transcutaneous CO2 (TcPCO2) in awake spontaneously breathing individuals, considering the overshoot phenomenon (transient overestimation of arterial PaCO2). EXPERIMENTAL SECTION: Observational study of 91 (75 men) individuals undergoing forced spirometry, measurement of SpO2 and TcPCO2 with the SenTec monitor every two minutes until minute 20 and arterial blood gas (ABG) analysis. Overshoot severity: (a) mild (0.1–1.9 mm Hg); (b) moderate (2–4.9 mm Hg); (c) severe: (>5 mm Hg). The mean difference was calculated for SpO2 and TcPCO2 and arterial values of PaCO2 and SpO2. The intraclass correlation coefficient (ICC) between monitor readings and blood values was calculated as a measure of agreement. RESULTS: The mean age was 63.1 ± 11.8 years. Spirometric values: FVC: 75.4 ± 6.2%; FEV1: 72.9 ± 23.9%; FEV1/FVC: 70 ± 15.5%. ABG: PaO2: 82.6 ± 13.2; PaCO2: 39.9.1 ± 4.8 mmHg; SaO2: 95.3 ± 4.4%. Overshoot analysis: overshoot was mild in 33 (36.3%) patients, moderate in 20 (22%) and severe in nine (10%); no overshoot was observed in 29 (31%) patients. The lowest mean differences between arterial blood gas and TcPCO2 was −0.57 mmHg at minute 10, although the highest ICC was obtained at minutes 12 and 14 (>0.8). The overshoot lost its influence after minute 12. For SpO2, measurements were reliable at minute 2. CONCLUSIONS: The optimal clinical reading measurement recommended for the ear lobe TcPCO2 measurement ranges between minute 12 and 14. The SpO2 measurement can be performed at minute 2. PMID:22315552

Tracked 3D ultrasound in radio-frequency liver ablation

NASA Astrophysics Data System (ADS)

Boctor, Emad M.; Fichtinger, Gabor; Taylor, Russell H.; Choti, Michael A.

2003-05-01

Recent studies have shown that radio frequency (RF) ablation is a simple, safe and potentially effective treatment for selected patients with liver metastases. Despite all recent therapeutic advancements, however, intra-procedural target localization and precise and consistent placement of the tissue ablator device are still unsolved problems. Various imaging modalities, including ultrasound (US) and computed tomography (CT) have been tried as guidance modalities. Transcutaneous US imaging, due to its real-time nature, may be beneficial in many cases, but unfortunately, fails to adequately visualize the tumor in many cases. Intraoperative or laparoscopic US, on the other hand, provides improved visualization and target imaging. This paper describes a system for computer-assisted RF ablation of liver tumors, combining navigational tracking of a conventional imaging ultrasound probe to produce 3D ultrasound imaging with a tracked RF ablation device supported by a passive mechanical arm and spatially registered to the ultrasound volume.

An update on the use of laser technology in skin vaccination

PubMed Central

Chen, Xinyuan; Wang, Ji; Shah, Dilip; Wu, Mei X

2014-01-01

Vaccination via skin often induces stronger immune responses than via muscle. This, in line with potential needle-free, painless delivery, makes skin a very attractive site for immunization. Yet, despite decades of effort, effective skin delivery is still in its infant stage and safe and potent adjuvants for skin vaccination remain largely undefined. We have shown that laser technologies including both fractional and non-fractional lasers can greatly augment vaccine-induced immune response without incurring any significant local and systemic side effects. Laser illumination at specific settings can accelerate the motility of antigen-presenting cells or trigger release of ‘danger’ signals stimulating the immune system. Moreover, several other groups including the authors explore laser technologies for needle-free transcutaneous vaccine delivery. As these laser-mediated resurfacing technologies are convenient, safe and cost-effective, their new applications in vaccination warrant clinical studies in the very near future. PMID:24127871

Methodological quality in randomised controlled trials of transcutaneous electric nerve stimulation for pain: low fidelity may explain negative findings.

PubMed

Bennett, Michael I; Hughes, Nicola; Johnson, Mark I

2011-06-01

The benefits of transcutaneous electrical nerve stimulation (TENS) for pain relief have not been reliably established, as most systematic reviews find poor methodological quality in many studies. The paradox within the evidence base for TENS is that despite identified sources of bias that may lead to an overestimation of treatment effects, no benefits for TENS can be clearly demonstrated. Conventional assessments of quality assume a single direction of bias, and little work has been undertaken examining other directions of bias. Our hypothesis was that low fidelity in studies (bias leading to an underestimation of treatment effects) may account for inconclusive findings. We included 38 studies from 3 recently published Cochrane systematic reviews that examined TENS for acute, chronic, and cancer pain. We extracted data relating to treatment allocation, application of TENS and to the assessment of outcomes. We quantified these data and judged this against standardised assessment criteria using a "traffic light" approach based on the number of studies reaching the standard. We identified significant sources of potential bias in both directions in relation to study design and implementation fidelity that have not been quantified previously. Suboptimal dosing of TENS and inappropriate outcome assessment were particularly prevalent weaknesses indicating low fidelity. We propose criteria for judging directions of bias in future studies of TENS that may be adapted to assess other trials in which implementation fidelity is important, such as other nonpharmacological interventions for pain. Poor implementation fidelity was identified as a significant source of bias in systematic reviews of TENS studies and might explain lack of consistent treatment effects of TENS in pain. Here, criteria for assessing methodology are proposed for use in designing future clinical trials of TENS. Copyright © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Dysregulation of the Descending Pain System in Temporomandibular Disorders Revealed by Low-Frequency Sensory Transcutaneous Electrical Nerve Stimulation: A Pupillometric Study

PubMed Central

Monaco, Annalisa; Cattaneo, Ruggero; Mesin, Luca; Ortu, Eleonora; Giannoni, Mario; Pietropaoli, Davide

2015-01-01

Using computerized pupillometry, our previous research established that the autonomic nervous system (ANS) is dysregulated in patients suffering from temporomandibular disorders (TMDs), suggesting a potential role for ANS dysfunction in pain modulation and the etiology of TMD. However, pain modulation hypotheses for TMD are still lacking. The periaqueductal gray (PAG) is involved in the descending modulation of defensive behavior and pain through μ, κ, and δ opioid receptors. Transcutaneous electrical nerve stimulation (TENS) has been extensively used for pain relief, as low-frequency stimulation can activate µ receptors. Our aim was to use pupillometry to evaluate the effect of low-frequency TENS stimulation of μ receptors on opioid descending pathways in TMD patients. In accordance with the Research Diagnostic Criteria for TMD, 18 females with myogenous TMD and 18 matched-controls were enrolled. All subjects underwent subsequent pupillometric evaluations under dark and light conditions before, soon after (end of stimulation) and long after (recovery period) sensorial TENS. The overall statistics derived from the darkness condition revealed no significant differences in pupil size between cases and controls; indeed, TENS stimulation significantly reduced pupil size in both groups. Controls, but not TMD patients, displayed significant differences in pupil size before compared with after TENS. Under light conditions, TMD patients presented a smaller pupil size compared with controls; the pupil size was reduced only in the controls. Pupil size differences were found before and during TENS and before and after TENS in the controls only. Pupillometry revealed that stimulating the descending opioid pathway with low-frequency sensory TENS of the fifth and seventh pairs of cranial nerves affects the peripheral target. The TMD patients exhibited a different pattern of response to TENS stimulation compared with the controls, suggesting that impaired modulation of the descending pain system may be involved in TMD. PMID:25905862

No Influence of Transcutaneous Electrical Nerve Stimulation on Exercise-Induced Pain and 5-Km Cycling Time-Trial Performance

PubMed Central

Hibbert, Andrew W.; Billaut, François; Varley, Matthew C.; Polman, Remco C. J.

2017-01-01

Introduction: Afferent information from exercising muscle contributes to the sensation of exercise-induced muscle pain. Transcutaneous electrical nerve stimulation (TENS) delivers low–voltage electrical currents to the skin, inhibiting nociceptive afferent information. The use of TENS in reducing perceptions of exercise-induced pain has not yet been fully explored. This study aimed to investigate the effect of TENS on exercise-induced muscle pain, pacing strategy, and performance during a 5-km cycling time trial (TT). Methods: On three separate occasions, in a single-blind, randomized, and cross-over design, 13 recreationally active participants underwent a 30-min TENS protocol, before performing a 5-km cycling TT. TENS was applied to the quadriceps prior to exercise under the following conditions; control (CONT), placebo with sham TENS application (PLAC), and an experimental condition with TENS application (TENS). Quadriceps fatigue was assessed with magnetic femoral nerve stimulation assessing changes in potentiated quadriceps twitch force at baseline, pre and post exercise. Subjective scores of exertion, affect and pain were taken every 1-km. Results: During TTs, application of TENS did not influence pain perceptions (P = 0.68, ηp2 = 0.03). There was no significant change in mean power (P = 0.16, ηp2 = 0.16) or TT duration (P = 0.17, ηp2 = 0.14), although effect sizes were large for these two variables. Changes in power output were not significant but showed moderate effect sizes at 500-m (ηp2 = 0.10) and 750-m (ηp2 = 0.10). Muscle recruitment as inferred by electromyography data was not significant, but showed large effect sizes at 250-m (ηp2 = 0.16), 500-m (ηp2 = 0.15), and 750-m (ηp2 = 0.14). This indicates a possible effect for TENS influencing performance up to 1-km. Discussion: These findings do not support the use of TENS to improve 5-km TT performance. PMID:28223939

Transcutaneous spinal direct current stimulation induces lasting fatigue resistance and enhances explosive vertical jump performance

PubMed Central

Tate, Rothwelle J.; Conway, Bernard A.

2017-01-01

Transcutaneous spinal direct current stimulation (tsDCS) is a non-invasive neuromodulatory intervention that has been shown to modify excitability in spinal and supraspinal circuits in animals and humans. Our objective in this study was to explore the functional neuromodulatory potential of tsDCS by examining its immediate and lasting effects over the repeated performance of a whole body maximal exercise in healthy volunteers. Using a double-blind, randomized, crossover, sham-controlled design we investigated the effects of 15 min of anodal tsDCS on repeated vertical countermovement jump (VCJ) performance at 0, 20, 60, and 180 minutes post-stimulation. Measurements of peak and take-off velocity, vertical displacement, peak power and work done during countermovement and push-off VCJ phases were derived from changes in vertical ground reaction force (12 performance parameters) in 12 healthy participants. The magnitude and direction of change in VCJ performance from pre- to post-stimulation differed significantly between sham and active tsDCS for 7 of the 12 VCJ performance measures (P < 0.05). These differences comprised of a post-sham fatigue in VCJ displacement/work done, peak to peak power and take-off velocity, and a resilience to this fatigue effect post-active tsDCS. In addition there was also an enhancement of countermovement performance and total work done (P < 0.05). These changes did not vary across repeated VCJ performances over time post-tsDCS (P > 0.05). Our original findings demonstrate that one single session of anodal tsDCS in healthy subjects can prevent fatigue and maintain or enhance different aspects of whole body explosive motor power over repeated sets of VCJs performed over a period of three hours. The observed effects are discussed in relation to alterations in central fatigue mechanisms, muscle contraction mode during jump execution and changes in spinal cord excitability. These findings have important implications for power endurance sport performance and for neuromotor rehabilitation. PMID:28379980

Detection of microcirculatory impairment by transcutaneous oxymetry monitoring during hemodialysis: an observational study

PubMed Central

2014-01-01

Background Little is known about the effects of intermittent hemodialysis on microcirculatory perfusion. The aim of this study is to assess the effects of hemodialysis on microvascular perfusion using transcutaneous oxymetry (TCPO2). Methods In this observational study, hourly TCPO2 measurements were performed during hemodialysis sessions. Ankle brachial index (ABI) was carried out to classify patients according their vascular condition. Results 50 patients (mean age 70 ± 8 years old) were enrolled. Mean TCPO2 decreased significantly on average 23.9% between start and finish of hemodialysis. Severe ischemia (TCPO2 < 30 mmHg) and critical ischemia (TCPO2 < 10 mmHg) occurred during dialysis in 47.1% and 15.5% respectively. Critical ischemia occurred only in limbs with ABI < 0.9 (8.3%) or > 1.3 (28%). Patients with critical ischemia experienced a significantly larger decline in mean blood pressure (32.4 ± 26.1 mmHg vs 12.7 ± 10.7 mmHg; P = 0.007) and a more pronounced ultrafiltration (45.55 ± 16.9 ml/kg vs 35.17 ± 18.2 ml/kg; P = 0.04) compared to patients without ischemia. Clinical outcomes (death or vascular procedures) were five times more frequent in patients who had developed critical ischemia (55.7% vs 10.1% P = 0.01). The elevated age of patients, the low basal value of TCPO2, and the occurrence of critical ischemia were more frequently associated with clinical outcome (P = 0.03, P = 0.048, P = 0.01 respectively). Conclusions This study demonstrates that hemodialysis induces microcirculatory injury, dependent on blood pressure reduction, peripheral vascular state and ultrafiltration. The occurrence of critical ischemia is associated to pejorative patient outcome and therefore, TCPO2 seems to be useful to avoid potential distal tissue damage during hemodialysis. PMID:24400914

Combination of Foot Stimulation and Tramadol Treatment Reverses Irritation Induced Bladder Overactivity in Cats

PubMed Central

Mally, Abhijith D.; Zhang, Fan; Matsuta, Yosuke; Shen, Bing; Wang, Jicheng; Roppolo, James R.; de Groat, William C.; Tai, Changfeng

2013-01-01

Purpose We determined whether transcutaneous electrical foot stimulation combined with a low dose of tramadol (Sigma-Aldrich®) could completely suppress bladder overactivity. Materials and Methods Repeat cystometrograms were performed in 18 α-chloralose anesthetized cats by infusing the bladder with saline or 0.25% acetic acid. Transcutaneous electrical stimulation (5 Hz) of the cat hind foot at 2 to 4 times the threshold intensity needed to induce observable toe movement was applied to suppress acetic acid induced bladder overactivity. Tramadol (1 to 3 mg/kg intravenously) was administered to enhance foot inhibition. Results Acetic acid irritated the bladder, induced bladder overactivity and significantly decreased bladder capacity to a mean ± SE of 26% ± 5% of saline control capacity (p <0.01). Without tramadol, foot stimulation at 2 and 4 threshold intensity applied during acetic acid cystometrograms significantly increased bladder capacity to a mean of 47% ± 5% and 62% ± 6% of saline control capacity, respectively (p <0.05). Without foot stimulation, tramadol (1 mg/kg) only slightly changed bladder capacity to a mean of 39% ± 2% of saline control capacity (p >0.05), while 3 mg/kg significantly increased capacity to 85% ± 14% that of control (p <0.05). However, 1 mg/kg tramadol combined with foot stimulation increased bladder capacity to a mean of 71% ± 18% (2 threshold intensity) and 84% ± 14% (4 threshold intensity), respectively, which did not significantly differ from saline control capacity. In addition, long lasting (greater than 1.5 to 2 hours) post-stimulation inhibition was induced by foot stimulation combined with 3 mg/kg tramadol treatment. Conclusions This study suggests a new treatment strategy for overactive bladder by combining foot stimulation with a low dose of tramadol, which is noninvasive and has potentially high efficacy and fewer adverse effects. PMID:23088991

Role of photoacoustic effects occurring at laser perforation of skin and laser transcutaneous drug delivery

NASA Astrophysics Data System (ADS)

Zharov, Vladimir P.; Latyshev, Alexei S.

2000-05-01

A further study is given of photoacoustic (PA) drug delivery technologies using an Er:YAG laser, with the main emphasis being placed on the laser perforation of skin and on PA impregnation using an additional covering quartz plate. A mathematical model based on Fick's law for PA impregnation with regard to a free and rigid interface is considered. The histological examination of the perforated guinea-pig skin ex vivo shoed that a powerful PA wave forced skin epidermis to be bent inwards. In biopsies taken 15 min later the nuclei pyknosis of epidermis cells lining the perforated channel was observed. In biopsies obtained 36 hours later an insignificant necrotic lesion remained, whereas 120 hours laser the cells recovered. I twas shown experimentally that the PA signal increased 30 times after applying a quartz plate over the drug solution, which substantially enhanced drug penetration through the skin .The dependancies were obtained of the penetration depth of the haematoporphyrin derivative photosensitizer versus the number of laser pulses and the pressing force applied to the quartz plate. The chromatographic fractionation of Diprospan and Dexamethasone hormonal preparations prior to and after the action of 200 Er:YAG laser-induced PA waves demonstrated that no additional chemical agents resulting from drug dissociation were detected. The application of laser drug delivery methods in respect of treating dermatological diseases is also discussed.

Pressure signatures can influence tissue response for individuals supported on an alternating pressure mattress.

PubMed

Chai, C Y; Sadou, O; Worsley, P R; Bader, D L

2017-08-01

Prolonged mechanical loading can lead to the breakdown of skin and underlying tissues which can, in turn, develop into a pressure ulcer. The benefits of pressure relief and/or redistribution to minimise risk have been well documented. Manufacturers have developed alternating air pressure mattresses (APAMs) to provide periodic relief for individuals on prolonged bed-rest. The present study describes the development of a control system, termed Pneumatic Manager which can vary the signature of an APAM, namely its pressure amplitude, cell profile and cycle period. An experimental array was designed to investigate the effects of varying these parameters, particularly with respect to its ability to maintain skin viability in a group of five healthy volunteers lying in a supine position. Transcutaneous gas (T c PO 2 /T c PCO 2 ) tensions at the sacrum were monitored. In addition, pressures and microclimate parameters at the loaded support interface were also measured. In the majority of test conditions the alternating support produced sacral T c PO 2 values, which either remained relatively high or fluctuated in concert with cycle period providing adequate viability. However, in 46% of cases at the extreme pressure amplitude of 100/0 mmHg, there was compromise to the skin viability at the sacrum, as reflected in depressed T c PO 2 levels associated with an elevation of T c PCO 2 levels above the normal range. In all cases, both the humidity and temperature levels increased during the test period. It is interesting to note that interface pressures at the sacrum rarely exceeded 60 mmHg. Although such studies need to be extended to involve bed-bound individuals, the results provide a design template for the optimum pressure signatures of APAM systems to ensure maintenance of skin viability during pronged loading. Copyright © 2017 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

Helmet Versus Nasal-Prong CPAP in Infants With Acute Bronchiolitis.

PubMed

Mayordomo-Colunga, Juan; Rey, Corsino; Medina, Alberto; Martínez-Camblor, Pablo; Vivanco-Allende, Ana; Concha, Andrés

2018-04-01

Nasal prongs are frequently used to deliver noninvasive CPAP in bronchiolitis, especially in the youngest children. A helmet interface is an alternative that might be comparable to nasal prongs. We sought to compare these interfaces. We performed a prospective, randomized, crossover, single-center study in an 8-bed multidisciplinary pediatric ICU in a university hospital. Infants age <3 months who were consecutively admitted to the pediatric ICU during a bronchiolitis epidemic season and fulfilled inclusion criteria were recruited. Subjects were randomly allocated to receive CPAP via a helmet or nasal prongs for 60 min. The subjects were then placed on the other CPAP system for another 60-min period (helmet then nasal prongs [H-NP] or nasal prongs then helmet [NP-H]). Measurements were taken at 30, 60, 90, and 120 min. Failure was defined as the need for further respiratory support. Sixteen subjects were included, with 9 in the H-NP group and 7 in the NP-H group. CPAP significantly reduced respiratory distress, showing no differences between the H-NP and NP-H groups in terms of improving the Modified Wood's Clinical Asthma Score from 4.8 ± 1 to 3 ± 0.9 and 2.7 ± 1.7 points at 60 min and 120 min in the H-NP group, respectively, and from 4.2 ± 0.9 to 2.8 ± 0.9 and to 2.9 ± 0.9 at 60 min and 120 min, respectively, in the NP-H group. Sedatives were used in only 3 subjects (2 in the NP-H group, P = .77). The failure rate was similar in both groups (3 of 9 subjects vs 3 of 7 subjects, P = .70). No significant differences were seen for heart rate, breathing frequency, F IO 2 , or transcutaneous oxygen saturation response. Our results suggest that CPAP delivered by nasal prongs and CPAP delivered by helmet are similar in terms of efficacy in young infants with acute bronchiolitis. Copyright © 2018 by Daedalus Enterprises.

Potential energy landscape of an interstitial O2 molecule in a SiO2 film near the SiO2/Si(001) interface

NASA Astrophysics Data System (ADS)

Ohta, Hiromichi; Watanabe, Takanobu; Ohdomari, Iwao

2008-10-01

Potential energy distribution of interstitial O2 molecule in the vicinity of SiO2/Si(001) interface is investigated by means of classical molecular simulation. A 4-nm-thick SiO2 film model is built by oxidizing a Si(001) substrate, and the potential energy of an O2 molecule is calculated at Cartesian grid points with an interval of 0.05 nm in the SiO2 film region. The result shows that the potential energy of the interstitial site gradually rises with approaching the interface. The potential gradient is localized in the region within about 1 nm from the interface, which coincides with the experimental thickness of the interfacial strained layer. The potential energy is increased by about 0.62 eV at the SiO2/Si interface. The result agrees with a recently proposed kinetic model for dry oxidation of silicon [Phys. Rev. Lett. 96, 196102 (2006)], which argues that the oxidation rate is fully limited by the oxidant diffusion.

Time-resolved determination of the potential of zero charge at polycrystalline Au/ionic liquid interfaces

NASA Astrophysics Data System (ADS)

Vargas-Barbosa, Nella M.; Roling, Bernhard

2018-05-01

The potential of zero charge (PZC) is a fundamental property that describes the electrode/electrolyte interface. The determination of the PZC at electrode/ionic liquid interfaces has been challenging due to the lack of models that fully describe these complex interfaces as well as the non-standardized approaches used to characterize them. In this work, we present a method that combines electrode immersion transient and impedance measurements for the determination of the PZC. This combined approach allows the distinction of the potential of zero free charge (pzfc), related to fast double layer charging on a millisecond timescale, from a potential of zero charge on a timescale of tens of seconds related to slower ion transport processes at the interface. Our method highlights the complementarity of these electrochemical techniques and the importance of selecting the correct timescale to execute experiments and interpret the results.

Cutaneous Recording and Stimulation of Muscles Using Organic Electronic Textiles.

PubMed

Papaiordanidou, Maria; Takamatsu, Seiichi; Rezaei-Mazinani, Shahab; Lonjaret, Thomas; Martin, Alain; Ismailova, Esma

2016-08-01

Electronic textiles are an emerging field providing novel and non-intrusive solutions for healthcare. Conducting polymer-coated textiles enable a new generation of fully organic surface electrodes for electrophysiological evaluations. Textile electrodes are able to assess high quality muscular monitoring and to perform transcutaneous electrical stimulation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of low-power laser radiation on mast cells function and biogenic amines content in stress

NASA Astrophysics Data System (ADS)

Brill, Gregory E.; Dobrovolsky, Gennady A.; Romanova, Tatyana P.; Brill, Alexander G.

1997-06-01

In experiments on white male rats stress was modeled by combined action of immobilization and sound stimulus during 2 h. It was established that stress induced storage of secretory material and accumulation of biogenic amines in mast cells. Preliminary transcutaneous He-Ne laser irradiation prevented stress-induced changes.

The role of charge transfer in the energy level alignment at the pentacene/C60 interface.

PubMed

Beltrán, J; Flores, F; Ortega, J

2014-03-07

Understanding the mechanism of energy level alignment at organic-organic interfaces is a crucial line of research to optimize applications in organic electronics. We address this problem for the C60-pentacene interface by performing local-orbital Density Functional Theory (DFT) calculations, including the effect of the charging energies on the energy gap of both organic materials. The results are analyzed within the induced density of interface states (IDIS) model. We find that the induced interface potential is in the range of 0.06-0.10 eV, in good agreement with the experimental evidence, and that such potential is mainly induced by the small, but non-negligible, charge transfer between the two compounds and the multipolar contribution associated with pentacene. We also suggest that an appropriate external intercompound potential could create an insulator-metal transition at the interface.

High concentration effects of neutral-potential-well interface traps on recombination dc current-voltage lineshape in metal-oxide-silicon transistors

NASA Astrophysics Data System (ADS)

Chen, Zuhui; Jie, Bin B.; Sah, Chih-Tang

2008-11-01

Steady-state Shockley-Read-Hall kinetics is employed to explore the high concentration effect of neutral-potential-well interface traps on the electron-hole recombination direct-current current-voltage (R-DCIV) properties in metal-oxide-silicon field-effect transistors. Extensive calculations include device parameter variations in neutral-trapping-potential-well electron interface-trap density NET (charge states 0 and -1), dopant impurity concentration PIM, oxide thickness Xox, forward source/drain junction bias VPN, and transistor temperature T. It shows significant distortion of the R-DCIV lineshape by the high concentrations of the interface traps. The result suggests that the lineshape distortion observed in past experiments, previously attributed to spatial variation in surface impurity concentration and energy distribution of interface traps in the silicon energy gap, can also arise from interface-trap concentration along surface channel region.

Atomistic calculations of interface elastic properties in noncoherent metallic bilayers

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

Mi Changwen; Jun, Sukky; Kouris, Demitris A.

2008-02-15

The paper describes theoretical and computational studies associated with the interface elastic properties of noncoherent metallic bicrystals. Analytical forms of interface energy, interface stresses, and interface elastic constants are derived in terms of interatomic potential functions. Embedded-atom method potentials are then incorporated into the model to compute these excess thermodynamics variables, using energy minimization in a parallel computing environment. The proposed model is validated by calculating surface thermodynamic variables and comparing them with preexisting data. Next, the interface elastic properties of several fcc-fcc bicrystals are computed. The excess energies and stresses of interfaces are smaller than those on free surfacesmore » of the same crystal orientations. In addition, no negative values of interface stresses are observed. Current results can be applied to various heterogeneous materials where interfaces assume a prominent role in the systems' mechanical behavior.« less

Electrokinetic motion of a spherical micro particle at an oil-water interface in microchannel.

PubMed

Wang, Chengfa; Li, Mengqi; Song, Yongxin; Pan, Xinxiang; Li, Dongqing

2018-03-01

The electrokinetic motion of a negatively charged spherical particle at an oil-water interface in a microchannel is numerically investigated and analyzed in this paper. A three-dimensional (3D) transient numerical model is developed to simulate the particle electrokinetic motion. The channel wall, the surface of the particle and the oil-water interface are all considered negatively charged. The effects of the direct current (DC) electric field, the zeta potentials of the particle-water interface and the oil-water interface, and the dynamic viscosity ratio of oil to water on the velocity of the particle are studied in this paper. In addition, the influences of the particle size are also discussed. The simulation results show that the micro-particle with a small value of negative zeta potential moves in the same direction of the external electric field. However, if the zeta potential value of the particle-water interface is large enough, the moving direction of the particle is opposite to that of the electric field. The velocity of the particle at the interface increases with the increase in the electric field strength and the particle size, but decreases with the increase in the dynamic viscosity ratio of oil to water, and the absolute value of the negative zeta potentials of both the particle-water interface and the oil-water interface. This work is the first numerical study of the electrokinetic motion of a charged particle at an oil-water interface in a microchannel. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Predictors of outcome in children and adolescents with overactive bladder treated with parasacral transcutaneous electrical nerve stimulation.

PubMed

Hoffmann, Anselmo; Sampaio, Clara; Nascimento, Ana Aparecida; Veiga, Maria Luiza; Barroso, Ubirajara

2018-02-01

Parasacral transcutaneous electrical nerve stimulation (TENS) has emerged as an effective treatment for overactive bladder (OAB) in view of its high success rates in improving lower urinary tract symptoms and constipation, with no direct side effects. However, the clinical characteristics associated with the outcomes remain to be established. The aim of this study was to evaluate potential predictors of outcome in children with OAB treated using parasacral TENS. This was a prospective study of children with symptoms of isolated OAB, enrolled consecutively to the study and treated with parasacral TENS (figure). Isolated OAB was defined as the presence of urinary urgency with no signs of dysfunctional voiding. The symptoms were considered completely resolved when a patient's parents/guardians or the patients themselves reported a 100% improvement. Parasacral TENS was performed twice weekly for a total of 20 sessions of 20 min each at 10 Hz. The potential predictive factors evaluated were: sex, age, daytime incontinence, nocturia, a prior history of urinary tract infection, the presence of nocturnal enuresis, constipation and holding maneuvers. Eighty-three patients with a mean age of 7.8 ± 2.8 years were included in the study. Complete resolution of symptoms was achieved in 47 (56.6%). Following parasacral TENS treatment, a significant response was reported in 96.4% of cases. Of the 55 patients with nocturnal enuresis, partial resolution was achieved in 30 cases (54.5%), with a statistically significant association between nocturnal enuresis and the patient's response to treatment (p < 0.004; OR = 4.4, 95% CI 1.5-12.5). No other factor was associated with response to treatment. To the best of our knowledge, this association between nocturnal enuresis and failure to respond to parasacral TENS treatment for lower urinary tract dysfunction has not previously been reported. The identification of factors capable of predicting therapeutic failure may allow professionals to select those specific patients who would benefit from a multimodal approach in the treatment of this pathology, which has such a significant impact on the quality of life of affected patients. Nocturnal enuresis was the only symptom associated with a poor outcome following parasacral TENS treatment in children with OAB. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Positive zeta potential of a negatively charged semi-permeable plasma membrane

NASA Astrophysics Data System (ADS)

Sinha, Shayandev; Jing, Haoyuan; Das, Siddhartha

2017-08-01

The negative charge of the plasma membrane (PM) severely affects the nature of moieties that may enter or leave the cells and controls a large number of ion-interaction-mediated intracellular and extracellular events. In this letter, we report our discovery of a most fascinating scenario, where one interface (e.g., membrane-cytosol interface) of the negatively charged PM shows a positive surface (or ζ) potential, while the other interface (e.g., membrane-electrolyte interface) still shows a negative ζ potential. Therefore, we encounter a completely unexpected situation where an interface (e.g., membrane-cytosol interface) that has a negative surface charge density demonstrates a positive ζ potential. We establish that the attainment of such a property by the membrane can be ascribed to an interplay of the nature of the membrane semi-permeability and the electrostatics of the electric double layer established on either side of the charged membrane. We anticipate that such a membrane property can lead to such capabilities of the cell (in terms of accepting or releasing certain kinds of moieties as well regulating cellular signaling) that was hitherto inconceivable.

Electrostatic complementarity at protein/protein interfaces.

PubMed

McCoy, A J; Chandana Epa, V; Colman, P M

1997-05-02

Calculation of the electrostatic potential of protein-protein complexes has led to the general assertion that protein-protein interfaces display "charge complementarity" and "electrostatic complementarity". In this study, quantitative measures for these two terms are developed and used to investigate protein-protein interfaces in a rigorous manner. Charge complementarity (CC) was defined using the correlation of charges on nearest neighbour atoms at the interface. All 12 protein-protein interfaces studied had insignificantly small CC values. Therefore, the term charge complementarity is not appropriate for the description of protein-protein interfaces when used in the sense measured by CC. Electrostatic complementarity (EC) was defined using the correlation of surface electrostatic potential at protein-protein interfaces. All twelve protein-protein interfaces studied had significant EC values, and thus the assertion that protein-protein association involves surfaces with complementary electrostatic potential was substantially confirmed. The term electrostatic complementarity can therefore be used to describe protein-protein interfaces when used in the sense measured by EC. Taken together, the results for CC and EC demonstrate the relevance of the long-range effects of charges, as described by the electrostatic potential at the binding interface. The EC value did not partition the complexes by type such as antigen-antibody and proteinase-inhibitor, as measures of the geometrical complementarity at protein-protein interfaces have done. The EC value was also not directly related to the number of salt bridges in the interface, and neutralisation of these salt bridges showed that other charges also contributed significantly to electrostatic complementarity and electrostatic interactions between the proteins. Electrostatic complementarity as defined by EC was extended to investigate the electrostatic similarity at the surface of influenza virus neuraminidase where the epitopes of two monoclonal antibodies, NC10 and NC41, overlap. Although NC10 and NC41 both have quite high values of EC for their interaction with neuraminidase, the similarity in electrostatic potential generated by the two on the overlapping region of the epitopes is insignificant. Thus, it is possible for two antibodies to recognise the electrostatic surface of a protein in dissimilar ways.

Excitability of Spinal Motor Neuron Function after the Transcutaneous Electrical Stimulation (TES) in Healthy Subjects -F-wave Study.

PubMed

Hirose, Hiroaki; Suzuki, Toshiaki; Shimada, Tomoaki

2006-01-01

To clarify the excitability of spinal motor neuron function after transcutaneous electrical stimulation (TES), we investigated the F-wave before and after TES. Fourteen healthy volunteers with a mean age of 23.4 years were studied. TES was applied to the flexor hallucis brevis (FHB) for 15 minutes. F-wave and M-wave were recorded from the FHB after tibial nerve stimulation at the ankle before TES, just after TES, 10, 20 and 30 minutes after TES. TES evoked full flexion of the great toe. F-wave was analyzed for the amplitude ratio of F/M, latency and duration. The amplitude ratio of F/ M was 3.1% before TES, 1.4% just after TES, 1.6% 10 minutes after, 1.9% 20 minutes after and 1.7% 30 minutes after TES. Each amplitude ratio of F/M after TES was significantly lower than that before TES (p<0.05). There was no statistically significant difference in the latency and the duration. These results suggest that the excitability of spinal motor neuron function after TES to muscles under this condition was reduced in healthy subjects.

Low Intensity Laser Therapy (LILT) Versus Transcutaneous Electrical Nerve Stimulation On Microcirculation In Diabetic Neuropathy

NASA Astrophysics Data System (ADS)

Battecha, Kadria H.; Atya, Azza M.

2011-09-01

Reduced microcirculation is a morbid element of neuropathy and one of the most common complications of uncontrolled diabetes. Many physical modalities have gained a considerable attention for enhancing cutaneous microcirculation in diabetic patients and prevent its serious complications. Accordingly, the present study was conducted to compare between the effect of low intensity laser therapy (LILT) and transcutaneous electrical nerve stimulation (TENS) on microcirculation in diabetic neuropathy. Thirty diabetic polyneuropathic patients ranged in age from 45-60 years participated in this study. They were randomly divided into two groups of equal number; patients in group (A) received LILT on plantar surface of foot with a dose of 3 J/cm2 and wavelength (904 nm), while those in group (B) received TENS on lower leg for 30 minutes with frequency (2 HZ). Treatment was conducted 3 times/week for 6 weeks. The cutaneous microcirculation was evaluated by Laser Doppler flowmetry at the baseline and at the end of treatment. Results revealed that group (A) showed statistically significant increase in the cutaneous microcirculation compared with group (B). So, it was concluded that LILT has to be more efficient than TENS in increasing cutaneous microcirculation in patients with diabetic neuropathy.

Effect of transcutaneous electrical nerve stimulation therapy for the treatment of primary dysmenorrheal.

PubMed

Bai, Hai-Yan; Bai, Hong-Yan; Yang, Zhi-Qin

2017-09-01

This study aimed to investigate the effect and safety of transcutaneous electrical nerve stimulation (TENS) therapy for relieving pain in women with primary dysmenorrhea (PD). In this study, 134 participants with PD were randomly divided into the intervention group and the sham group, with 67 participants in each group. Participants in the intervention group received TENS, whereas those in the sham group received sham TENS. The primary outcome was measured by the Numeric Rating Scale (NRS). The secondary outcomes were measured by the duration of relief from dysmenorrheal pain, number of ibuprofen tablets taken, and the World Health Organization quality of life (WHOQOL)-BREF score, as well as the adverse events. A total of 122 participants completed the study. Compared to sham TENS, TENS showed a greater effect in pain relief with regard to the NRS (P < .01), duration of relief from dysmenorrheal pain (P < .01), and number of ibuprofen tablets taken (P < .01). However, no significant differences in the quality of life, measured by the WHOQOL-BREF score, were found between 2 groups. The adverse event profiles were also similar between 2 groups. TENS was efficacious and safe in relieving pain in participants with PD.

A Prospective Comparison of Transcutaneous and Serum Bilirubin Within Brief Time Intervals.

PubMed

Jones, Denise F; McRea, Abigail R; Knowles, James D; Lin, Feng-Chang; Burnette, Erin; Reller, Lara A; Lohr, Jacob A

2017-10-01

The American Academy of Pediatrics recommends screening newborns ≥35 weeks' gestation with total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) to detect hyperbilirubinemia. Retrospective studies show TcB measurements strongly correlate with TSB; however, few prospective trials document this relationship. Furthermore, Dräger's newest TcB instrument, JM-105, remains unstudied in the United States. We measure TcB on foreheads and sternums of newborns using JM-105 and Bilichek devices within 30 minutes of TSB measurement. We find best overall TcB/TSB correlation with JM-105 on the sternum (mean TcB-TSB difference: -0.21 ± 1.15 mg/dL). Correlations between paired measurements for TcB on the sternum using JM-105 were 0.93 for all TSB levels (n = 178), 0.82 for TSB > 10 (n = 19), 0.69 for TSB > 12 (n = 11), and 0.52 for TSB > 15 (n = 6). TcB accuracy via JM-105 on the sternum significantly differed among races ( P < .001). For 5% of paired measurements, TcB with JM-105 on the sternum underestimated TSB by ≥2 mg/dL, and for <1% by ≥3 mg/dL.

Design and Evaluation of a Fully Implantable Control Unit for Blood Pumps

PubMed Central

Unthan, Kristin; Gräf, Felix; Laumen, Marco; Finocchiaro, Thomas; Sommer, Christoph; Lanmüller, Hermann; Steinseifer, Ulrich

2015-01-01

As the number of donor hearts is limited while more and more patients suffer from end stage biventricular heart failure, Total Artificial Hearts become a promising alternative to conventional treatment. While pneumatic devices sufficiently supply the patients with blood flow, the patient's quality of life is limited by the percutaneous pressure lines and the size of the external control unit. This paper describes the development of the control unit of the ReinHeart, a fully implantable Total Artificial Heart. General requirements for any implantable control unit are defined from a technical and medical point of view: necessity of a Transcutaneous Energy Transmission, autonomous operation, safety, geometry, and efficiency. Based on the requirements, a prototype is designed; it incorporates a LiFePo4 battery pack with charger, a rectifier for transcutaneous energy transmission, the motor's driver electronics, and a microcontroller which monitors and controls all functions. In validation tests, the control unit demonstrated a stable operation on TET and battery supply and a safe switching from one supply to the other. The overall mean efficiency is 14% on TET and 22% on battery supply. The control unit is suitable for chronic animal trials of the ReinHeart. PMID:26583095

[Breeding hygiene regimen and fertility performance in a swine herd of 400].

PubMed

Scharfe, S; Elze, K; Kraut, G; Gruhle, J

1997-04-01

A specific breeding schedule and the subsequent reproductive performance in a 400 swine breeding herd over five years is described. The reduction of the nursing time from 49 to 28 days increased the number of litters per anno to 2.4 and of weaned piglets by six. The reproductive management is based on the 7-day-breeding schedule. Each week 22 to 23 animals are inseminated, among them eight gilts every 14 days. Mating gilts only every 14 days reduce the cost for transportation. The zoo- and biotechnique is as follows: Sows: weaning on Wednesday; 24 h later 900 IE pregnant mare serum gonadotropin (PMSG) i.m., artificial insemination (AI) on Monday or Tuesday (two times), pregnancy diagnosis by transcutaneous ultrasonography on day 23/24 post insemination. Gilts: transportation (gilts are bought-in) exactly four weeks before insemination; on Saturday/ Sunday transportation induced heat; 23 days after transportation (18th/19th day of female cycle), on Friday 900 IE PMSG (with sows simultaneously); on Monday 150 micrograms GnRH-analogue i.m.; on Wednesday/Thursday AI (two times; the 2nd AI 14 h after the first), pregnancy diagnosis by transcutaneous ultrasonography on day 23/24 post insemination.

A pilot study on using acupuncture and transcutaneous electrical nerve stimulation to treat chronic non-specific low back pain.

PubMed

Itoh, Kazunori; Itoh, Satoko; Katsumi, Yasukazu; Kitakoji, Hiroshi

2009-02-01

The present study tests whether a combined treatment of acupuncture and transcutaneous electrical nerve stimulation (TENS) is more effective than acupuncture or TENS alone for treating chronic low back pain (LBP). Thirty-two patients with chronic LBP were randomly allocated to four groups. The acupuncture group (ACP) received only acupuncture treatment at selected acupoints for low back pain; the TENS group (TENS) received only TENS treatment at pain areas; the acupuncture and TENS group (A&T) received both acupuncture and TENS treatments; the control group (CT) received topical poultice (only when necessary). Each group received specific weekly treatment five times during the study. Outcome measures were pain intensity in terms of visual analogue scale (VAS) and QOL of low back in terms of Roland-Morris Disability Questionnaire (RDQ). The ACP, TENS and A&T groups all reported lower VAS and RDQ scores. Significant reduction in pain intensity (P<0.008) and significant improvement in QOL (P<0.008) were shown in the A&T group. Combined acupuncture and TENS treatment is effective in pain relief and QOL of low back improvement for the sampled patients suffering from chronic LBP.

Optical transcutaneous bilirubin detector

DOEpatents

Kronberg, J.W.

1993-11-09

A transcutaneous bilirubin detector is designed comprising a source of light having spectral components absorbable and not absorbable by bilirubin, a handle assembly, electronic circuitry and a fiber optic bundle connecting the assembly to the light source and circuitry. Inside the assembly is a prism that receives the light from one end of the fiber optic bundle and directs it onto the skin and directs the reflected light back into the bundle. The other end of the bundle is trifucated, with one end going to the light source and the other two ends going to circuitry that determines how much light of each kind has been reflected. A relatively greater amount absorbed by the skin from the portion of the spectrum absorbable by bilirubin may indicate the presence of the illness. Preferably, two measurements are made, one on the kneecap and one on the forehead, and compared to determine the presence of bilirubin. To reduce the impact of light absorption by hemoglobin in the blood carried by the skin, pressure is applied with a plunger and spring in the handle assembly, the pressure limited by points of a button slidably carried in the assembly that are perceived by touch when the pressure applied is sufficient. 6 figures.

Optical transcutaneous bilirubin detector

DOEpatents

Kronberg, J.W.

1991-03-04

This invention consists of a transcutaneous bilirubin detector comprising a source of light having spectral components absorbable and not absorbable by bilirubin, a handle assembly, electronic circuitry and a fiber optic bundle connecting the assembly to the light source and circuitry. Inside the assembly is a prism that receives the light from one end of the fiber optic bundle and directs it onto the skin and directs the reflected light back into the bundle. The other end of the bundle is trifucated, with one end going to the light source and the other two ends going to circuitry that determines how much light of each kind has been reflected. A relatively greater amount absorbed by the skin from the portion of the spectrum absorbable by bilirubin may indicate the presence of the illness. Preferably, two measurements are made, one on the kneecap and one on the forehead, and compared to determine the presence of bilirubin. To reduce the impact of light absorption by hemoglobin in the blood carried by the skin, pressure is applied with a plunger and spring in the handle assembly, the pressure limited by points of a button slidably carried in the assembly that are perceived by touch when the pressure applied is sufficient.

Optical transcutaneous bilirubin detector

DOEpatents

Kronberg, James W.

1993-01-01

A transcutaneous bilirubin detector comprising a source of light having spectral components absorbable and not absorbable by bilirubin, a handle assembly, electronic circuitry and a fiber optic bundle connecting the assembly to the light source and circuitry. Inside the assembly is a prism that receives the light from one end of the fiber optic bundle and directs it onto the skin and directs the reflected light back into the bundle. The other end of the bundle is trifucated, with one end going to the light source and the other two ends going to circuitry that determines how much light of each kind has been reflected. A relatively greater amount absorbed by the skin from the portion of the spectrum absorbable by bilirubin may indicate the presence of the illness. Preferably, two measurements are made, one on the kneecap and one on the forehead, and compared to determine the presence of bilirubin. To reduce the impact of light absorption by hemoglobin in the blood carried by the skin, pressure is applied with a plunger and spring in the handle assembly, the pressure limited by points of a button slidably carried in the assembly that are perceived by touch when the pressure applied is sufficient.

Thoratec transcutaneous energy transformer system: a review and update.

PubMed

Rintoul, Thomas C; Dolgin, Alexander

2004-01-01

A transcutaneous energy transformer system (TETS) can provide power to an implanted ventricular assist device (VAD) across an unbroken layer of skin. A TETS includes a subcutaneous secondary coil, which traditionally connects to remote power conditioning circuitry located to avoid eddy current losses and heating that occur in metal near operating TETS coils. Litz wire, used to construct the coil and connect it to that circuitry, efficiently conducts the high frequency alternating current but is bulky and stiff. A novel concept (US Patent No. 6,327,504 B1) packages the secondary coil's output power conditioning circuitry within the unused aperture of the coil while minimizing eddy current losses. The concept allows use of a more flexible cable for its direct current power output. The result is improved reliability, functionality, and efficiency along with decreased implant volume and a thinner, more flexible lead system to interconnect to the VAD. This in turn enhances system versatility by expanding sites available for module implantation. A TETS using this concept has demonstrated efficiency exceeding 80% and peak power outputs of 45 W with good tissue compatibility in the bovine model after a 30 day implant.

Analysis of specific absorption rate and internal electric field in human biological tissues surrounding an air-core coil-type transcutaneous energy transmission transformer.

PubMed

Shiba, Kenji; Zulkifli, Nur Elina Binti; Ishioka, Yuji

2017-06-01

In this study, we analyzed the internal electric field E and specific absorption rate (SAR) of human biological tissues surrounding an air-core coil transcutaneous energy transmission transformer. Using an electromagnetic simulator, we created a model of human biological tissues consisting of a dry skin, wet skin, fat, muscle, and cortical bone. A primary coil was placed on the surface of the skin, and a secondary coil was located subcutaneously inside the body. The E and SAR values for the model representing a 34-year-old male subject were analyzed using electrical frequencies of 0.3-1.5 MHz. The transmitting power was 15 W, and the load resistance was 38.4 Ω. The results showed that the E values were below the International Commission on Non-ionizing Radiation Protection (ICNIRP) limit for the general public exposure between the frequencies of 0.9 and 1.5 MHz, and SAR values were well below the limit prescribed by the ICNIRP for the general public exposure between the frequencies of 0.3 and 1.2 MHz.

Focused ultrasound: concept for automated transcutaneous control of hemorrhage in austere settings.

PubMed

Kucewicz, John C; Bailey, Michael R; Kaczkowski, Peter J; Carter, Stephen J

2009-04-01

High intensity focused ultrasound (HIFU) is being developed for a range of clinical applications. Of particular interest to NASA and the military is the use of HIFU for traumatic injuries because HIFU has the unique ability to transcutaneously stop bleeding. Automation of this technology would make possible its use in remote, austere settings by personnel not specialized in medical ultrasound. Here a system to automatically detect and target bleeding is tested and reported. The system uses Doppler ultrasound images from a clinical ultrasound scanner for bleeding detection and hardware for HIFU therapy. The system was tested using a moving string to simulate blood flow and targeting was visualized by Schlieren imaging to show the focusing of the HIFU acoustic waves. When instructed by the operator, a Doppler ultrasound image is acquired and processed to detect and localize the moving string, and the focus of the HIFU array is electronically adjusted to target the string. Precise and accurate targeting was verified in the Schlieren images. An automated system to detect and target simulated bleeding has been built and tested. The system could be combined with existing algorithms to detect, target, and treat clinical bleeding.

Development and evaluation of totally implantable ventricular assist system using a vibrating flow pump and transcutaneous energy transmission system with amorphous fibers.

PubMed

Yambe, T; Hashimoto, H; Kobayashi, S; Sonobe, T; Naganuma, S; Nanka, S S; Matsuki, H; Yoshizawa, M; Tabayashi, K; Takayasu, H; Takeda, H; Nitta, S

1997-01-01

We have developed a vibrating flow pump (VFP) that can generate oscillated blood flow with a relatively high frequency (10-50 Hz) for a totally implantable ventricular assist system (VAS). To evaluate the newly developed VAS, left heart bypasses, using the VFP, were performed in chronic animal experiments. Hemodynamic parameters were recorded in a data recorder in healthy adult goats during an awake condition and analyzed in a personal computer system through an alternating-direct current converter. Basic performance of the total system with a transcutaneous energy transmission system were satisfactory. During left ventricular assistance with the VFP, Mayer wave fluctuations of hemodynamics were decreased in the power spectrum, the fractal dimensions of the hemodynamics were significantly decreased, and peripheral vascular resistance was significantly decreased. These results suggest that cardiovascular regulatory nonlinear dynamics, which mediate the hemodynamics, may be affected by left ventricular bypass with oscillated flow. The decreased power of the Mayer wave in the spectrum caused the limit cycle attractor of the hemodynamics and decreased peripheral resistance. These results suggest that this newly developed VAS is useful for the totally implantable system with unique characteristics that can control hemodynamic properties.

Treatment of ischemic ulcers of the lower limbs with alprostadil (prostaglandin E1).

PubMed

Tondi, Paolo; Gerardino, Laura; Santoliquido, Angelo; Pola, Roberto; Gabrielli, Maurizio; Papaleo, Pierangelo; Gasbarrini, Antonio; Pola, Paolo; Flore, Roberto

2004-08-01

Hemodynamic, hemorheologic, and metabolic changes are main determinants in the genesis of ischemic leg ulcers. Because prostaglandin E1 (alprostadil) could successfully counteract these changes, it has been intravenously used in the treatment of this disease. The aim of this study was to evaluate the efficacy of alprostadil in the treatment of ischemic ulcers and to compare subcutaneous with intravenous administration. Eighty patients were enrolled. Twenty-five were treated by injecting low doses of alprostadil around ischemic ulcers of the leg and saline solution intravenously and 25 were treated with intravenous alprostadil and local injections of saline solution; the control group was composed of 30 patients who received saline solution around the ulcers and intravenously. All patients showed a statistically significant improvement in ulcer diameter, pain, and transcutaneous oxygen pressure compared to the control group. No relevant differences in the clinical outcome in the two treated groups were found, but patients treated with subcutaneous alprostadil experienced no side effects and showed higher values of transcutaneous oxygen pressure. Both intravenous and local subcutaneous alprostadil are useful in the treatment of ischemic leg ulcers, but subcutaneous administration is less expensive and easier to perform.

[Intraoperative monitoring in artificial respiration of premature and newborn infants. I. Monitoring of respiratory parameters and alveolar ventilation].

PubMed

Lenz, G; Heipertz, W; Leidig, E; Madee, S

1986-06-01

Monitoring of ventilation serves to ensure adequate alveolar ventilation and arterial oxygenation, and to avoid pulmonary damage due to mechanical ventilation. Basic clinical monitoring, i.e., inspection, auscultation (including precordial or oesophageal stethoscope) and monitoring of heart rate and blood pressure, is mandatory. Mechanical ventilation is monitored by ventilation pressures (peak pressure, plateau pressure and endexpiratory pressure), ventilation volumes (measured at the in/expiratory valve of the respirator and by hot-wire anemometry at the tube connector), ventilation rate, and inspiratory oxygen concentration (FiO2). Alveolar ventilation should be continuously and indirectly recorded by capnometry (pECO2) and by measurement of transcutaneous pCO2 (tcpCO2), whereas oxygenation is determined via measurement of transcutaneous pO2 (tcpO2). Invasive monitoring of gas exchange is essential in prolonged or intrathoracic interventions as well as in neonates with cardiopulmonary problems. paCO2 may be estimated by capillary or venous blood gas analysis; arterial blood gas analysis is required for exact determination of paCO2 as well as arteriocutaneous pCO2 (atcDCO2) and arterio-end-expiratory (aEDCO2) gradients.

Electromagnetic Compatibility of Transcutaneous Energy Transmission Systemfor Totally Implantable Artificial Heart

NASA Astrophysics Data System (ADS)

Shiba, Kenji; Koshiji, Kohji

Transcutaneous Energy Transmission (TET) is one way of providing the energy needed to power a totally implantable artificial heart (TIAH). In the present study, an externally coupled TET system was implanted in a prototype human phantom to evaluate emission and immunity. In the emission evaluation, measurements were conducted based on CISPR Pub.11 and VDE 0871 standards, while immunity tests were based on the standards of the IEC 61000-4 series. The magnetic field of the radiated emission was measured using a loop antenna. At 0.1[MHz], we found the greatest magnetic field of 47.8 [dBμA/m], somewhat less than CISPR’s upper limit of 54 [dBμA/m]. For the conducted emission, by installing a noise filter and ferrite beads in the input section of the DC-power supply, conducted emission could be kept within the allowable limits of CISPR Pub.11 and VDE 0871. Finally, the immunity tests against radiated and conducted emission, electrostatic discharge and voltage fluctuation proved that the prototype could withstand the maximum level of disturbance. These results confirmed that the TET system implanted in a human phantom could, through modification, meet the emission and immunity standards.

A high-performance transcutaneous battery charger for medical implants.

PubMed

Artan, N; Vanjani, Hitesh; Vashist, Gurudath; Fu, Zhen; Bhakthavatsala, Santosh; Ludvig, Nandor; Medveczky, Geza; Chao, H

2010-01-01

As new functionality is added to the implantable devices, their power requirements also increase. Such power requirements make it hard for keeping such implants operational for long periods by non-rechargeable batteries. This result in a need for frequent surgeries to replace these batteries. Rechargeable batteries can satisfy the long-term power requirements of these new functions. To minimize the discomfort to the patients, the recharging of the batteries should be as infrequent as possible. Traditional battery charging methods have low battery charging efficiency. This means they may limit the amount of charge that can be delivered to the device, speeding up the depletion of the battery and forcing frequent recharging. In this paper, we evaluate the suitability of a state-of-the-art general purpose charging method called current-pumped battery charger (CPBC) for implant applications. Using off-the-shelf components and with minimum optimization, we prototyped a proof-of-concept transcutaenous battery charger based on CPBC and show that the CPBC can charge a 100 mAh battery transcutaneously within 137 minutes with at most 2.1°C increase in tissue temperature even with a misalignment of 1.3 cm in between the coils, while keeping the battery charging efficiency at 85%.

Micropower circuits for bidirectional wireless telemetry in neural recording applications.

PubMed

Neihart, Nathan M; Harrison, Reid R

2005-11-01

State-of-the art neural recording systems require electronics allowing for transcutaneous, bidirectional data transfer. As these circuits will be implanted near the brain, they must be small and low power. We have developed micropower integrated circuits for recovering clock and data signals over a transcutaneous power link. The data recovery circuit produces a digital data signal from an ac power waveform that has been amplitude modulated. We have also developed an FM transmitter with the lowest power dissipation reported for biosignal telemetry. The FM transmitter consists of a low-noise biopotential amplifier and a voltage controlled oscillator used to transmit amplified neural signals at a frequency near 433 MHz. All circuits were fabricated in a standard 0.5-microm CMOS VLSI process. The resulting chip is powered through a wireless inductive link. The power consumption of the clock and data recovery circuits is measured to be 129 microW; the power consumption of the transmitter is measured to be 465 microW when using an external surface mount inductor. Using a parasitic antenna less than 2 mm long, a received power level was measured to be -59.73 dBm at a distance of one meter.

Transcutaneous in vivo Raman spectroscopic studies in a mouse model: evaluation of changes in the breast associated with pregnancy and lactation

NASA Astrophysics Data System (ADS)

Bhattacharjee, Tanmoy; Maru, Girish; Ingle, Arvind; Krishna, C. Murali

2013-04-01

Raman spectroscopy (RS) has been extensively explored as an alternative diagnostic tool for breast cancer. This can be attributed to its sensitivity to malignancy-associated biochemical changes. However, biochemical changes due to nonmalignant conditions like benign lesions, inflammatory diseases, aging, menstrual cycle, pregnancy, and lactation may act as confounding factors in diagnosis of breast cancer. Therefore, in this study, the efficacy of RS to classify pregnancy and lactation-associated changes as well as its effect on breast tumor diagnosis was evaluated. Since such studies are difficult in human subjects, a mouse model was used. Spectra were recorded transcutaneously from the breast region of six Swiss bare mice postmating, during pregnancy, and during lactation. Data were analyzed using multivariate statistical tool Principal Component-Linear Discriminant Analysis. Results suggest that RS can differentiate breasts of pregnant/lactating mice from those of normal mice, the classification efficiencies being 100%, 60%, and 88% for normal, pregnant, and lactating mice, respectively. Frank breast tumors could be classified with 97.5% efficiency, suggesting that these physiological changes do not affect the ability of RS to detect breast tumors.

The electrochemistry of "solid/water" interfaces involved in PEM-H2O reactors: part I. The "Pt/water" interfaces.

PubMed

Wang, Qiang; Cha, Chuan-Sin; Lu, Juntao; Zhuang, Lin

2009-01-28

The nature and properties of Pt surfaces in contact with pure water in PEM-H2O reactors were mimetically studied by employing CV measurements with microelectrode techniques. These "Pt/water" interfaces were found to be electrochemically polarizable, and the local interfacial potential relative to reversible hydrogen electrode (RHE) potential in pure water is numerically the same as the potential value measured against a RHE in contact with PEM as the reference electrode. However, the structural parameters of the electric double layer at the "Pt/water" interfaces can be quite different from those at the "Pt/PEM" interfaces, and the kinetics of electrode processes could be seriously affected by the structure of electric double layer in pure water media. Besides, there is active diffusional flow of intermediates of electrode reactions between the "Pt/water" and the "Pt/PEM" interfaces, thus facilitating the active involvement of the "Pt/water" interfaces in the current-generation mechanism of PEM fuel cells and other types of PEM-H2O reactors.

Energy dispersive-EXAFS of Pd nucleation at a liquid/liquid interface

NASA Astrophysics Data System (ADS)

Chang, S.-Y.; Booth, S. G.; Uehara, A.; Mosselmans, J. F. W.; Cibin, G.; Pham, V.-T.; Nataf, L.; Dryfe, R. A. W.; Schroeder, S. L. M.

2016-05-01

Energy dispersive extended X-ray absorption fine structure (EDE) has been applied to Pd nanoparticle nucleation at a liquid/liquid interface under control over the interfacial potential and thereby the driving force for nucleation. Preliminary analysis focusing on Pd K edge-step height determination shows that under supersaturated conditions the concentration of Pd near the interface fluctuate over a period of several hours, likely due to the continuous formation and dissolution of sub-critical nuclei. Open circuit potential measurements conducted ex-situ in a liquid/liquid electrochemical cell support this view, showing that the fluctuations in Pd concentration are also visible as variations in potential across the liquid/liquid interface. By decreasing the interfacial potential through inclusion of a common ion (tetraethylammonium, TEA+) the Pd nanoparticle growth rate could be slowed down, resulting in a smooth nucleation process. Eventually, when the TEA+ ions reached an equilibrium potential, Pd nucleation and particle growth were inhibited.

Potential-specific structure at the hematite-electrolyte interface

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

McBriarty, Martin E.; Stubbs, Joanne; Eng, Peter

The atomic-scale structure of interfaces between metal oxides and aqueous electrolytes controls their catalytic, geochemical, and corrosion behavior. Measurements that probe these interfaces in situ provide important details of ion and solvent arrangements, but atomically precise structural models do not exist for common oxide-electrolyte interfaces far from equilibrium. Using a novel cell, we measured the structure of the hematite (a-Fe 2O 3) (110more » $$\\bar{2}$$)-electrolyte interface under controlled electrochemical bias using synchrotron crystal truncation rod X ray scattering. At increasingly cathodic potentials, charge-compensating protonation of surface oxygen groups increases the coverage of specifically bound water while adjacent water layers displace outwardly and became disordered. Returning to open circuit potential leaves the surface in a persistent metastable protonation state. The flux of current and ions at applied potential is thus regulated by a unique interfacial electrolyte environment, suggesting that electrical double layer models should be adapted to the dynamically changing interfacial structure far from equilibrium.« less

Captured by the pain: pain steady-state evoked potentials are not modulated by selective spatial attention.

PubMed

Blöchl, Maria; Franz, Marcel; Miltner, Wolfgang H R; Weiss, Thomas

2015-04-07

Attention has been shown to affect the neural processing of pain. However, the exact mechanisms underlying this modulation remain unknown. Here, we used a new method called pain steady-state evoked potentials (PSSEPs) to investigate whether selective spatial attention affects EEG responses to tonic painful stimuli. In general, steady-state evoked potentials reflect changes in the EEG spectrum at a certain frequency that correspond to the frequency of a train of applied stimuli. In this study, high intensity transcutaneous electrical stimulation was delivered to both hands simultaneously with 31 Hz and 37 Hz, respectively. Subject׳s attention was directed to one of the two trains of stimulation in order to detect a small gap that was occasionally interspersed into the stimulus trains. Thereby, they had to ignore the stimulation applied to the other hand. Results show that PSSEPs were induced at 31 Hz and 37 Hz at frontal and central electrodes. PSSEPs occurred contralaterally to the respective hand stimulated with that frequency. Surprisingly, the magnitude of PSSEPs was not modulated by spatial attention towards one of the two stimuli. Our results indicate that attention can hardly be shifted between two simultaneously applied tonic painful stimulations. Copyright © 2015 Elsevier B.V. All rights reserved.

Functional recordings from awake, behaving rodents through a microchannel based regenerative neural interface

NASA Astrophysics Data System (ADS)

Gore, Russell K.; Choi, Yoonsu; Bellamkonda, Ravi; English, Arthur

2015-02-01

Objective. Neural interface technologies could provide controlling connections between the nervous system and external technologies, such as limb prosthetics. The recording of efferent, motor potentials is a critical requirement for a peripheral neural interface, as these signals represent the user-generated neural output intended to drive external devices. Our objective was to evaluate structural and functional neural regeneration through a microchannel neural interface and to characterize potentials recorded from electrodes placed within the microchannels in awake and behaving animals. Approach. Female rats were implanted with muscle EMG electrodes and, following unilateral sciatic nerve transection, the cut nerve was repaired either across a microchannel neural interface or with end-to-end surgical repair. During a 13 week recovery period, direct muscle responses to nerve stimulation proximal to the transection were monitored weekly. In two rats repaired with the neural interface, four wire electrodes were embedded in the microchannels and recordings were obtained within microchannels during proximal stimulation experiments and treadmill locomotion. Main results. In these proof-of-principle experiments, we found that axons from cut nerves were capable of functional reinnervation of distal muscle targets, whether regenerating through a microchannel device or after direct end-to-end repair. Discrete stimulation-evoked and volitional potentials were recorded within interface microchannels in a small group of awake and behaving animals and their firing patterns correlated directly with intramuscular recordings during locomotion. Of 38 potentials extracted, 19 were identified as motor axons reinnervating tibialis anterior or soleus muscles using spike triggered averaging. Significance. These results are evidence for motor axon regeneration through microchannels and are the first report of in vivo recordings from regenerated motor axons within microchannels in a small group of awake and behaving animals. These unique findings provide preliminary evidence that efferent, volitional motor potentials can be recorded from the microchannel-based peripheral neural interface; a critical requirement for any neural interface intended to facilitate direct neural control of external technologies.

40 CFR 63.1046 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Method 21 of 40 CFR part 60, appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak... 60, appendix A. (7) Each potential leak interface shall be checked by traversing the instrument probe...

40 CFR 63.1046 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Method 21 of 40 CFR part 60, appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak... 60, appendix A. (7) Each potential leak interface shall be checked by traversing the instrument probe...

40 CFR 63.1046 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Method 21 of 40 CFR part 60, appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak... 60, appendix A. (7) Each potential leak interface shall be checked by traversing the instrument probe...

40 CFR 63.945 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated... determined according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak...

40 CFR 63.945 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated... determined according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak...

40 CFR 63.945 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated... determined according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak...

Controlling the electronic and geometric structures of 2D insertions to realize high performance metal/insertion-MoS2 sandwich interfaces.

PubMed

Su, Jie; Feng, Liping; Zeng, Wei; Liu, Zhengtang

2017-06-08

Metal/insertion-MoS 2 sandwich interfaces are designed to reduce the Schottky barriers at metal-MoS 2 interfaces. The effects of geometric and electronic structures of two-dimensional (2D) insertion materials on the contact properties of metal/insertion-MoS 2 interfaces are comparatively studied by first-principles calculations. Regardless of the geometric and electronic structures of 2D insertion materials, Fermi level pinning effects and charge scattering at the metal/insertion-MoS 2 interface are weakened due to weak interactions between the insertion and MoS 2 layers, no gap states and negligible structural deformations for MoS 2 layers. The Schottky barriers at metal/insertion-MoS 2 interfaces are induced by three interface dipoles and four potential steps that are determined by the charge transfers and structural deformations of 2D insertion materials. The lower the electron affinities of 2D insertion materials, the more are the electrons lost from the Sc surface, resulting in lower n-type Schottky barriers at Sc/insertion-MoS 2 interfaces. The larger the ionization potentials and the thinner the thicknesses of 2D insertion materials, the fewer are the electrons that accumulate at the Pt surface, leading to lower p-type Schottky barriers at Pt/insertion-MoS 2 interfaces. All Sc/insertion-MoS 2 interfaces exhibited ohmic characters. The Pt/BN-MoS 2 interface exhibits the lowest p-type Schottky barrier of 0.52 eV due to the largest ionization potential (∼6.88 eV) and the thinnest thickness (single atomic layer thickness) of BN. These results in this work are beneficial to understand and design high performance metal/insertion-MoS 2 interfaces through 2D insertion materials.

Interface Reactions and Synthetic Reaction of Composite Systems

PubMed Central

Park, Joon Sik; Kim, Jeong Min

2010-01-01

Interface reactions in composite systems often determine their overall properties, since product phases usually formed at interfaces during composite fabrication processing make up a large portion of the composites. Since most composite materials represent a ternary or higher order materials system, many studies have focused on analyses of diffusion phenomena and kinetics in multicomponent systems. However, the understanding of the kinetic behavior increases the complexity, since the kinetics of each component during interdiffusion reactions need to be defined for interpreting composite behaviors. From this standpoint, it is important to clarify the interface reactions for producing compatible interfaces with desired product phases. A thermodynamic evaluation such as a chemical potential of involving components can provide an understanding of the diffusion reactions, which govern diffusion pathways and product phase formation. A strategic approach for designing compatible interfaces is discussed in terms of chemical potential diagrams and interface morphology, with some material examples.

Stimulation of the peripheral nervous system for pain control.

PubMed

Long, D M

1983-01-01

Transcutaneous stimulation is a proven effective way to relieve pain. Its optimal use requires an accurate patient diagnosis. Treatment of pain as a symptom only is likely to fail. There must be a careful psychosocial evaluation, for the majority of patients who come to the doctor complaining of pain have major psychological, social, or behavioral factors that are most important in the genesis of the complaint. Drug abuse must be corrected. Related symptoms, such as anxiety and depression, must be treated. Then, a thorough trail of transcutaneous stimulation is mandatory. A desultory use will undoubtedly lead to failure. This trial must begin with patient education by experienced personnel. Then the electrodes must be properly applied, and there must be a regular follow-up of stimulation to be certain the patient is utilizing it correctly. The patient must be supported through an adequate trial which should extend over 2-4 weeks before purchase of the device is contemplated. Furthermore, all related nursing and physician personnel must be educated in the proper use of the technique. The uninformed professional who denigrates the therapy is a very effective deterrent to appropriate use. In this situation, transcutaneous electrical stimulation will be of great value in the treatment of acute musculoskeletal injury and acute postoperative pain. It will be effective in the treatment of peripheral nerve injury pain, chronic musculoskeletal abnormalities, chronic pain in the patient who has undergone multiple operations upon the low back and neck, visceral pain, some of the reflex sympathetic dystrophies, and postherpetic neuralgia. Stimulation will not help a complaint which is psychosomatic in origin. It will not influence drug addiction. It is not likely to be useful in any situation where secondary gain is important. The metabolic neuropathies, pain of spinal cord injury, and pain from cerebrovascular accident will not respond frequently enough to warrant more than hopeful trials. The technique is inexpensive, places the patient in control of his own pain, and has no known serious side effects. Its widespread application awaits the development of reasonable systems to provide this service to physicians and patients. Stimulation-induced analgesia deserves a place in the armamentarium of every physician dealing with the complaint of pain.

Parasacral transcutaneous electrical nerve stimulation for overactive bladder in constipated children: The role of constipation.

PubMed

Veiga, Maria Luiza; Costa, Elen Veruska; Portella, Inaah; Nacif, Ananda; Martinelli Braga, Ana Aparecida; Barroso, Ubirajara

2016-12-01

Parasacral transcutaneous electrical nerve stimulation (TENS) is an effective method for the treatment of overactive bladder (OAB), and, additionally, it accelerates bowel transit time. Therefore, not only does parasacral transcutaneous electrical nerve stimulation (TENS) improve lower urinary tract symptoms (LUTS), but it also resolves the problem of constipation in a significant number of children. Since TENS has a positive effect on LUTS and on the symptoms of fecal retention, it is possible that its action regarding OAB could be directly associated with the improvement in constipation. In other words, the positive effect of parasacral TENS in OAB would be because constipation was resolved. The objective of this study was to test that hypothesis. To test the hypothesis that the positive effect of parasacral TENS in OAB would be because constipation had improved with this method. In this prospective study, children with OAB alone were submitted to parasacral TENS. The inclusion criteria consisted of children with idiopathic OAB alone The Rome III criteria for children of 4-18 years of age were used to diagnose constipation. All the children were treated with 20 sessions of parasacral TENS applied for 20 min, three times weekly on alternating days (Figure). No instructions were given to the participants with respect to diet, laxatives, or pharmaceutical treatment for constipation throughout the study period. None of the patients used anticholinergics. Standard urotherapy was prescribed. Parasacral TENS improves OAB and constipation. The presence of constipation before treatment was not associated with a poorer prognosis insofar as the resolution of the symptoms of OAB was concerned. Likewise, there was no association between the resolution of constipation with parasacral TENS and the resolution of OAB. There was no statistically significant difference in urinary symptoms between the constipated and nonconstipated children. There was an improvement in urgency, urge incontinency and in holding maneuvers in both the constipated and non-constipated children; however, there was no significant improvement in enuresis. The resolution of OAB was not associated with the resolution of constipation and vice versa. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Effects of transcutaneous electrical nerve stimulation (TENS) on arterial stiffness and blood pressure in resistant hypertensive individuals: study protocol for a randomized controlled trial.

PubMed

Vilela-Martin, José Fernando; Giollo-Junior, Luiz Tadeu; Chiappa, Gaspar Rogério; Cipriano-Junior, Gerson; Vieira, Paulo José Cardoso; dos Santos Ricardi, Fábio; Paz-Landim, Manoel Ildefonso; de Andrade, Days Oliveira; Cestário, Elizabeth do Espírito Santo; Cosenso-Martin, Luciana Neves; Yugar-Toledo, Juan Carlos; Cipullo, José Paulo

2016-03-29

Resistant hypertension (RH) treatment requires an adequate and intense therapeutic approach. However, the results are not always satisfactory despite intensive treatment. Of the different pathophysiological mechanisms involved in the pathogenesis of RH, sympathetic overstimulation and therapies that block the sympathetic system have been widely studied. These approaches, however, are invasive and expensive. Another possible approach is by transcutaneous electrical nerve stimulation (TENS), a noninvasive method that modulates activity by using low-frequency transcutaneous electrical stimulation to inhibit primary afferent pathways. Thus, the current study will evaluate the effect of applying TENS in the cervicothoracic region of subjects with RH and will seek to develop a new low-cost and readily available therapy to treat this group of hypertensive individuals. This is a randomized, single blind (subject), parallel-assignment study controlled with a sham group and including participants aged 40 to 70 years with resistant hypertension. The trial has two arms: the treatment and control (sham group). The treatment group will be submitted to the stimulation procedure (TENS). The sham group will not be submitted to stimulation. The primary outcomes will be a reduction in the peripheral blood pressure and adverse events. The secondary outcomes will be a reduction the central blood pressure. The study will last 30 days. The sample size was calculated assuming an alpha error of 5 % to reject the null hypothesis with a statistical power of 80 %, thereby resulting in 28 participants per group (intervention versus sham). In recent decades, RH has become very common and costly. Adequate control requires several drugs, and in many cases, treatment is not successful. Sympathetic nervous system inhibition by renal denervation and central inhibition have significant effects in reducing BP; however, these treatments are costly and invasive. Another type of sympathetic nervous system inhibition can also be noninvasively achieved by electric current. Therefore, the application of TENS may be a new therapeutic option for treating resistant hypertensive individuals. Clinical Trials NCT02365974.

Transcutaneous immunization with a novel imiquimod nanoemulsion induces superior T cell responses and virus protection.

PubMed

Lopez, Pamela Aranda; Denny, Mark; Hartmann, Ann-Kathrin; Alflen, Astrid; Probst, Hans Christian; von Stebut, Esther; Tenzer, Stefan; Schild, Hansjörg; Stassen, Michael; Langguth, Peter; Radsak, Markus P

2017-09-01

Transcutaneous immunization (TCI) is a novel vaccination strategy utilizing the skin associated lymphatic tissue to induce immune responses. TCI using a cytotoxic T lymphocyte (CTL) epitope and the Toll-like receptor 7 (TLR7) agonist imiquimod mounts strong CTL responses by activation and maturation of skin-derived dendritic cells (DCs) and their migration to lymph nodes. However, TCI based on the commercial formulation Aldara only induces transient CTL responses that needs further improvement for the induction of durable therapeutic immune responses. Therefore we aimed to develop a novel imiquimod solid nanoemulsion (IMI-Sol) for TCI with superior vaccination properties suited to induce high quality T cell responses for enhanced protection against infections. TCI was performed by applying a MHC class I or II restricted epitope along with IMI-Sol or Aldara (each containing 5% Imiquimod) on the shaved dorsum of C57BL/6, IL-1R, Myd88, Tlr7 or Ccr7 deficient mice. T cell responses as well as DC migration upon TCI were subsequently analyzed by flow cytometry. To determine in vivo efficacy of TCI induced immune responses, CTL responses and frequency of peptide specific T cells were evaluated on day 8 or 35 post vaccination and protection in a lymphocytic choriomeningitis virus (LCMV) infection model was assessed. TCI with the imiquimod formulation IMI-Sol displayed equal skin penetration of imiquimod compared to Aldara, but elicited superior CD8 + as well as CD4 + T cell responses. The induction of T-cell responses induced by IMI-Sol TCI was dependent on the TLR7/MyD88 pathway and independent of IL-1R. IMI-Sol TCI activated skin-derived DCs in skin-draining lymph nodes more efficiently compared to Aldara leading to enhanced protection in a LCMV infection model. Our data demonstrate that IMI-Sol TCI can overcome current limitations of previous imiquimod based TCI approaches opening new perspectives for transcutaneous vaccination strategies and allowing the use of this enhanced cutaneous drug-delivery system to be tailored for the improved prevention and treatment of infectious diseases and cancers. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

[Observation of the use of percutaneous tracheostomy tube for closed drainage of pneumothorax in intensive care unit].

PubMed

Kang, Hongshan; Bai, Yan; Ma, Hongfang; Du, Zhiyong; Ma, Zhen; Wang, Huiqing; Liu, Yajing; Liu, Shuhong; Cui, Zhaobo

2014-12-01

To explore the effect of the transcutaneous tracheostomy tube in patients with pneumothorax and its clinical value. A prospective randomized controlled trial was conducted. Thirty-two patients with pneumothorax admitted to Department of Critical Care Medicine of Harrison International Peace Hospital of Hebei Medical University from June 2010 to June 2014 were enrolled. The patients were divided into control group and observation group, with 16 cases in each group. Beside the treatment for primary disease, the patients in control group received thoracic close drainage with traditional silica gel tube as performed by thoracic surgeons, and those in observation group received thoracic close drainage with transcutaneous tracheostomy tube by intensive care doctors. The curative effect and complications of the two groups were observed. Compared with control group, the time from diagnosis to operation (minutes:8.00 ± 1.36 vs. 23.06 ± 3.83, t=14.790, P=0.000) and the operation time were significantly shortened (days:5.37 ± 1.02 vs. 7.31 ± 1.70, t=7.286, P=0.000), the frequency of drainage tube replacement (times: 0.18 ± 0.40 vs. 3.87 ± 1.14, t=12.128, P=0.000) and the times of repeated chest radiography (times:1.12 ± 0.34 vs. 2.93 ± 0.77, t=8.589, P=0.000) in observation group were significantly reduced, the length of hospital day was significantly shortened (days:8.30 ± 1.37 vs. 24.56 ± 5.62, t=17.289, P=0.000), the rates of dislocation of drainage tube (0 vs. 3 cases), obstruction of the tube (0 vs. 5 cases), and subcutaneous emphysema (3 vs. 16 cases) were reduced obviously, but there was no difference in incidence of incision infection (1 vs. 3 cases) and infection of thoracic cavity (0 vs. 2 cases). The usage of transcutaneous tracheostomy tube in patients with pneumothorax is safe and simple. Doctors in ICU can independently do this procedure, and its effect is positive.

[The influence of non-invasive electrical stimulation of the spinal cord on the locomotor function of patients presenting with movement disorders of central genesis].

PubMed

Balykin, M V; Yakupov, R N; Mashin, V V; Kotova, E Yu; Balykin, Yu M; Gerasimenko, Yu P

The objective of the present study was to evaluate the influence of non-invasive (transcutaneous) electrical spinal cord stimulation on the locomotor function of the patients suffering from movement disorders. The study involved 10 patients of both sexes at the age from 32 to 70 years (including 40% of men and 60% of women) presenting with the compromised locomotor function of varying severity associated with the disturbances of cerebral blood circulation caused either by an injury to the brain and spinal cord or by stroke. The transcutaneous electrical spinal cord stimulation was applied using different frequency regimes with the placement of the electrodes in the projection onto the region of TXI-TXII vertebrae. The active factors were bipolar electrical stimuli 0.5 ms in duration; the current strength was chosen for each patient on an individual basis taking into consideration its threshold level. Electromyograms and evoked motor responses of selected muscles, viz. m. rectus femoris, m.biceps femoris, m. tibialis anterior, and m.gastrocnemius were recorded with the use of the 'Neuro-MVP-8 eight-channel electromyography' ('Neurosoft', Russia). The data obtained give evidence that the stimulation of the spinal cord with a frequency of 1 Hz induces reflectory responses with monosynaptic and polysynaptic components in the muscles of the lower extremities, with the thresholds of these responses being significantly higher in the patients presenting with serious neurological problems. Stimulation with the frequencies of 5 and 30 Hz caused in the patients with paresis the involuntary movement of the legs the characteristics of which were similar to those of the locomotor movements. It has been demonstrated that the application of transcutaneous electrical spinal cord stimulation leads to increased excitability of the lumbar spinal neural structures of the patients. The study has shown the possibility of regulation of the locomotor functions in the patients presenting with movement disorders of central genesis by means of non-invasive electrical stimulation of the spinal cord.

UROLOGIC ROBOTS AND FUTURE DIRECTIONS

PubMed Central

Mozer, Pierre; Troccaz, Jocelyne; Stoianovici, Dan

2009-01-01

Purpose of review Robot-assisted laparoscopic surgery in urology has gained immense popularity with the Da Vinci system but a lot of research teams are working on new robots. The purpose of this paper is to review current urologic robots and present future developments directions. Recent findings Future systems are expected to advance in two directions: improvements of remote manipulation robots and developments of image-guided robots. Summary The final goal of robots is to allow safer and more homogeneous outcomes with less variability of surgeon performance, as well as new tools to perform tasks based on medical transcutaneous imaging, in a less invasive way, at lower costs. It is expected that improvements for remote system could be augmented reality, haptic feed back, size reduction and development of new tools for NOTES surgery. The paradigm of image-guided robots is close to a clinical availability and the most advanced robots are presented with end-user technical assessments. It is also notable that the potential of robots lies much further ahead than the accomplishments of the daVinci system. The integration of imaging with robotics holds a substantial promise, because this can accomplish tasks otherwise impossible. Image guided robots have the potential to offer a paradigm shift. PMID:19057227

Urologic robots and future directions.

PubMed

Mozer, Pierre; Troccaz, Jocelyne; Stoianovici, Dan

2009-01-01

Robot-assisted laparoscopic surgery in urology has gained immense popularity with the daVinci system, but a lot of research teams are working on new robots. The purpose of this study is to review current urologic robots and present future development directions. Future systems are expected to advance in two directions: improvements of remote manipulation robots and developments of image-guided robots. The final goal of robots is to allow safer and more homogeneous outcomes with less variability of surgeon performance, as well as new tools to perform tasks on the basis of medical transcutaneous imaging, in a less invasive way, at lower costs. It is expected that improvements for a remote system could be augmented in reality, with haptic feedback, size reduction, and development of new tools for natural orifice translumenal endoscopic surgery. The paradigm of image-guided robots is close to clinical availability and the most advanced robots are presented with end-user technical assessments. It is also notable that the potential of robots lies much further ahead than the accomplishments of the daVinci system. The integration of imaging with robotics holds a substantial promise, because this can accomplish tasks otherwise impossible. Image-guided robots have the potential to offer a paradigm shift.

Transient Dupuit Interface Flow with partially penetrating features

NASA Astrophysics Data System (ADS)

Bakker, Mark

1998-11-01

A comprehensive potential is presented for Dupuit interface flow in coastal aquifers where both the fresh water and salt water are moving. The resulting potential flow problem may be solved, for incompressible confined aquifers, using analytic functions. The vertical velocity of the interface may then be computed analytically and the change of the position of the interface may be simulated by numerical integration through time, starting with a known (or estimated) initial position. The upconing of the interface below a partially penetrating ditch or well may be studied if Dupuit solutions for such features are available. A new Dupuit solution is derived for a ditch that penetrates the aquifer partially from above; a Dupuit solution for a partially penetrating well may be obtained following a similar derivation. The new Dupuit solution is combined with the interface solution to simulate the upconing of an initially horizontal interface below a series of partially penetrating ditches; the interface converges to the known steady state position.

Characterization of structural and electrostatic complexity in pentacene thin films by scanning probe microscopy

NASA Astrophysics Data System (ADS)

Puntambekar, Kanan Prakash

The advancement of organic electronics for applications in solar energy conversion, printed circuitry, displays, and solid-state lighting depends upon optimization of structure and properties for a variety of organic semiconductor interfaces. Organic semiconductor/insulator (O/I) and organic-metal (O/M) interfaces, in particular, are critical to the operation of organic thin film transistors (OTFTs) currently being developed for printed flexible electronics. Scanning probe microscopy (SPM) is a powerful tool to isolate and characterize the bottlenecks to charge transport at these interfaces. This thesis establishes a direct correlation between the structural disorder and electrical complexity at these interfaces, using various SPM based methods and discusses the implications of such complexity on device performance. To examine the O/M interfaces, surface potentials of operating pentacene TFTs with two different contact geometries (bottom or top) were mapped by Kelvin probe force microscopy (KFM). The surface potential distribution was used to isolate the potential drops at the source and drain contacts. Simultaneously obtained topography and surface potential maps elucidated the correlation between the morphology and contact resistance at the O/M interface; the bottom contact TFTs were observed to be contact limited at large gate voltages, while the top contact TFTs were not contact limited. A direct correlation between structural defects and electric potential variations at the pentacene and silicon dioxide, a common insulator, is demonstrated. Lateral force microscopy (LFM) generates striking images of the polycrystalline microstructure of a monolayer thick pentacene film, allowing clear visualization of the grain boundary network. Further more, surface potential wells localized at the grain boundaries were observed by KFM, suggesting that the grain boundaries may serve as charge carrier (hole) traps. Line dislocations were also revealed in the second monolayer by chemical etching and SPM and produce strong variations in the surface potential that must affect the interfacial charge conductance. Structural disorder at the O/I and O/M interfaces degrades both injection and transport of charge, and therefore needs to be minimized. Thus both visualization and correlation of structural and electrical complexity at these interfaces have important implications for understanding electrical transport in OTFTs and for defining strategies to improve device performance.

Combined use of two membrane-potential-sensitive dyes for determination of the Galvani potential difference across a biomimetic oil/water interface.

PubMed

Yoshimura, Tatsuya; Nagatani, Hirohisa; Osakai, Toshiyuki

2014-05-01

The fluorescence behavior of anionic membrane-potential-sensitive dyes, bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBAC4(3)) and bis-(1,3-diethylthiobarbituric acid)trimethine oxonol (DiSBAC2(3)), at a biomimetic 1,2-dichloroethane (DCE)/water (W) interface was studied by the mean of potential-modulated fluorescence (PMF) spectroscopy. The respective dyes gave a well-defined PMF signal due to the adsorption/desorption at the DCE/W interface. It was also found that the potentials where the two dyes gave the PMF signals were different by about 100 mV. We then attempted a combined use of the two dyes for determination of the Galvani potential difference across the DCE/W interface. When 40 μM DiBAC4(3) and 15 μM DiSBAC2(3) were initially added to the W phase, distinctly different spectra were obtained for different interfacial potentials. The ratio of the PMF signal intensities at 530 and 575 nm (the fluorescence maximum wavelengths for the respective dyes) showed a clear dependence on the interfacial potential. These results suggested the potential utility of the combined use of two dyes for the determination of membrane potentials in vivo.

'Fly Like This': Natural Language Interface for UAV Mission Planning

NASA Technical Reports Server (NTRS)

Chandarana, Meghan; Meszaros, Erica L.; Trujillo, Anna; Allen, B. Danette

2017-01-01

With the increasing presence of unmanned aerial vehicles (UAVs) in everyday environments, the user base of these powerful and potentially intelligent machines is expanding beyond exclusively highly trained vehicle operators to include non-expert system users. Scientists seeking to augment costly and often inflexible methods of data collection historically used are turning towards lower cost and reconfigurable UAVs. These new users require more intuitive and natural methods for UAV mission planning. This paper explores two natural language interfaces - gesture and speech - for UAV flight path generation through individual user studies. Subjects who participated in the user studies also used a mouse-based interface for a baseline comparison. Each interface allowed the user to build flight paths from a library of twelve individual trajectory segments. Individual user studies evaluated performance, efficacy, and ease-of-use of each interface using background surveys, subjective questionnaires, and observations on time and correctness. Analysis indicates that natural language interfaces are promising alternatives to traditional interfaces. The user study data collected on the efficacy and potential of each interface will be used to inform future intuitive UAV interface design for non-expert users.

Improved osseointegration with as-built electron beam melted textured implants and improved peri‑implant bone volume with whole body vibration.

PubMed

Ruppert, David S; Harrysson, Ola L A; Marcellin-Little, Denis J; Dahners, Laurence E; Weinhold, Paul S

2018-06-11

Transcutaneous osseointegrated prostheses provide stable connections to the skeleton while eliminating skin lesions experienced with socket prosthetics. Additive manufacturing can create custom textured implants capable of interfacing with amputees' residual bones. Our objective was to compare osseointegration of textured surface implants made by electron beam melting (EBM), an additive manufacturing process, to machine threaded implants. Whole body vibration was investigated to accelerate osseointegration. Two cohorts of Sprague-Dawley rats received bilateral, titanium implants (EBM vs. threaded) in their tibiae. One cohort comprising five groups vibrated at 45 Hz: 0.0 (control), 0.15, 0.3, 0.6 or 1.2 g was followed for six weeks. Osseointegration was evaluated through torsional testing and bone volume fraction (BV/TV). A second cohort, divided into two groups (control and 0.6 g), was followed for 24 days and evaluated for resonant frequency, bone-implant contact (BIC) and fluorochrome labeling. The EBM textured implants exhibited significantly improved mechanical stability independent of vibration, highlighting the benefits of using EBM to produce custom textured surfaces. Bone formation on and around the EBM textured implants increased compared to machined implants, as seen by BIC and fluorescence. No difference in torque, BIC or fluorescence among vibration levels was detected. BV/TV significantly increased at 0.6 g compared to control for both implant types. Copyright © 2018 IPEM. Published by Elsevier Ltd. All rights reserved.

Graphic Interfaces and Online Information.

ERIC Educational Resources Information Center

Percival, J. Mark

1990-01-01

Discusses the growing importance of the use of Graphic User Interfaces (GUIs) with microcomputers and online services. Highlights include the development of graphics interfacing with microcomputers; CD-ROM databases; an evaluation of HyperCard as a potential interface to electronic mail and online commercial databases; and future possibilities.…

Time to address the problems at the neural interface

NASA Astrophysics Data System (ADS)

Durand, Dominique M.; Ghovanloo, Maysam; Krames, Elliot

2014-04-01

Neural engineers have made significant, if not remarkable, progress in interfacing with the nervous system in the last ten years. In particular, neuromodulation of the brain has generated significant therapeutic benefits [1-5]. EEG electrodes can be used to communicate with patients with locked-in syndrome [6]. In the central nervous system (CNS), electrode arrays placed directly over or within the cortex can record neural signals related to the intent of the subject or patient [7, 8]. A similar technology has allowed paralyzed patients to control an otherwise normal skeletal system with brain signals [9, 10]. This technology has significant potential to restore function in these and other patients with neural disorders such as stroke [11]. Although there are several multichannel arrays described in the literature, the workhorse for these cortical interfaces has been the Utah array [12]. This 100-channel electrode array has been used in most studies on animals and humans since the 1990s and is commercially available. This array and other similar microelectrode arrays can record neural signals with high quality (high signal-to-noise ratio), but these signals fade and disappear after a few months and therefore the current technology is not reliable for extended periods of time. Therefore, despite these major advances in communicating with the brain, clinical translation cannot be implemented. The reasons for this failure are not known but clearly involve the interface between the electrode and the neural tissue. The Defense Advanced Research Project Agency (DARPA) as well as other federal funding agencies such as the National Science Foundation (NSF) and the National Institutes of Health have provided significant financial support to investigate this problem without much success. A recent funding program from DARPA was designed to establish the failure modes in order to generate a reliable neural interface technology and again was unsuccessful at producing a robust interface with the CNS. In 2013, two symposia were held independently to discuss this problem: one was held at the International Neuromodulation Society's 11th World Congress in Berlin and supported by the International Neuromodulation Society1 and the other at the 6th International Neural Engineering conference in San Diego2 and was supported by the NSF. Clearly, the neuromodulation and the neural engineering communities are keen to solve this problem. Experts from the field were assembled to discuss the problems and potential solutions. Although many important points were raised, few emerged as key issues. (1) The ability to access remotely and reliably internal neural signals . Although some of the technological problems have already been solved, this ability to access neural signals is still a significant problem since reliable and robust transcutaneous telemetry systems with large numbers of signals, each with wide bandwidth, are not readily available to researchers. (2) A translation strategy taking basic research to the clinic . The lack of understanding of the biological response to implanted constructs and the inability to monitor the sites and match the mechanical properties of the probe to the neural tissue properties continue to be an unsolved problem. In addition, the low levels of collaboration among neuroscientists, clinicians, patients and other stakeholders throughout different phases of research and development were considered to be significant impediments to progress. (3) Fundamental tools development procedures for neural interfacing . There are many laboratories testing various devices with different sets of criteria, but there is no consensus on the failure modes. The reliability, robustness of metrics and testing standards for such devices have not been established, either in academia or in industry. To start addressing this problem, the FDA has established a laboratory to test the reliability of some neural devices. Although the discussion was mostly centered on interfacing with the CNS, it has recently become clear that the peripheral nervous system (PNS) could be an important target for interfacing, perhaps even more accessible for interfacing than the CNS. A recent initiative called Bioelectronic Medicines3 is a step in that direction. A recent summit held in New York was organized to investigate novel and disruptive neural technologies to interface specifically with the PNS in order to restore health and biological function to organs. With significant interest in neurotechnology for neural interfacing (see footnotes 1, 2 and 3) and uncovering new ways to treat, prevent and cure brain disorders (President Obama's brain initiative4), it seems clear that the problems at the interface will not remain unsolved for long. Finding solutions to the problem at the neural interface for interacting with the nervous system (PNS and CNS) is crucial for understanding and restoring brain function. This would in turn have a significant impact on health care and quality of life for patients with neural disorders. References [1] Follett K A et al 2010 Pallidal versus subthalamic deep-brain stimulation for Parkinson's disease New Engl. J. Med. 362 2077-91 [2] Holtzheimer P E et al 2012 Subcallosal cingulate deep brain stimulation for treatment-resistant unipolar and bipolar depression Arch. Gen. Psychiatry 69 150 [3] Carron R, Chabardes S and Hammond C 2012 Mechanisms of action of high-frequency deep brain stimulation. A review of the literature and current concepts NeuroChirurgie 58 209-17 [4] Vidailhet M et al 2005 Bilateral deep-brain stimulation of the globus pallidus in primary generalized dystonia New Engl. J. Med. 352 459-67 [5] Theodore W H and Fisher R S 2004 Brain stimulation for epilepsy Lancet Neurol. 3 111-8 [6] Kübler A, Kotchoubey B, Kaiser J, Wolpaw J R and Birbaumer N 2001 Brain-computer communication: unlocking the locked Psychol. Bull. 127 358-75 [7] Schalk G, Miller K J, Anderson N R, Wilson J A, Smyth M D, Ojemann J G, Moran D W, Wolpaw J R and Leuthardt E C 2008 Two-dimensional movement control using electrocorticographic signals in humans J. Neural Eng. 5 75 [8] Serruya M D, Hatsopoulos N G, Paninski L, Fellows M R and Donoghue J P 2002 Brain-machine interface: instant neural control of a movement signal Nature 416 141-2 [9] Hochberg L R, Serruya M D, Friehs G M, Mukand J A, Saleh M, Caplan A H, Branner A, Chen D, Penn R D and Donoghue J P 2006 Neuronal ensemble control of prosthetic devices by a human with tetraplegia Nature 442 164-71 [10] Collinger J L et al 2013 High-performance neuroprosthetic control by an individual with tetraplegia Lancet 381 557-64 [11] Leuthardt E C, Schalk G, Wolpaw J R, Ojemann J G and Moran D W 2004 A brain-computer interface using electrocorticographic signals in humans J. Neural Eng. 1 63 [12] Maynard E M, Nordhausen C T and Normann R A 1997 The Utah intracortical electrode array: a recording structure for potential brain-computer interfaces Electroencephalogr. Clin. Neurophysiol. 102 228-39 1 www.neuromodulation.com/8-june-2013 2 http://neuro.embs.org/wp-content/uploads/sites/2/2013/05/SymposiumAdvert1.pdf 3 www.gsk.com/explore-gsk/how-we-do-r-and-d/bioelectronics.html 4 www.whitehouse.gov/share/brain-initiative

Klein tunneling in the α -T3 model

NASA Astrophysics Data System (ADS)

Illes, E.; Nicol, E. J.

2017-06-01

We investigate Klein tunneling for the α -T3 model, which interpolates between graphene and the dice lattice via parameter α . We study transmission across two types of electrostatic interfaces: sharp potential steps and sharp potential barriers. We find both interfaces to be perfectly transparent for normal incidence for the full range of the parameter α for both interfaces. For other angles of incidence, we find that transmission is enhanced with increasing α . For the dice lattice, we find perfect, all-angle transmission across a potential step for incoming electrons with energy equal to half of the height of the potential step. This is analogous to the "super", all-angle transmission reported for the dice lattice for Klein tunneling across a potential barrier.

Excess chemical potential of small solutes across water--membrane and water--hexane interfaces

NASA Technical Reports Server (NTRS)

Pohorille, A.; Wilson, M. A.

1996-01-01

The excess chemical potentials of five small, structurally related solutes, CH4, CH3F, CH2F2, CHF3, and CF4, across the water-glycerol 1-monooleate bilayer and water-hexane interfaces were calculated at 300, 310, and 340 K using the particle insertion method. The excess chemical potentials of nonpolar molecules (CH4 and CF4) decrease monotonically or nearly monotonically from water to a nonpolar phase. In contrast, for molecules that possess permanent dipole moments (CH3F, CH2F, and CHF3), the excess chemical potentials exhibit an interfacial minimum that arises from superposition of two monotonically and oppositely changing contributions: electrostatic and nonelectrostatic. The nonelectrostatic term, dominated by the reversible work of creating a cavity that accommodates the solute, decreases, whereas the electrostatic term increases across the interface from water to the membrane interior. In water, the dependence of this term on the dipole moment is accurately described by second order perturbation theory. To achieve the same accuracy at the interface, third order terms must also be included. In the interfacial region, the molecular structure of the solvent influences both the excess chemical potential and solute orientations. The excess chemical potential across the interface increases with temperature, but this effect is rather small. Our analysis indicates that a broad range of small, moderately polar molecules should be surface active at the water-membrane and water-oil interfaces. The biological and medical significance of this result, especially in relation to the mechanism of anesthetic action, is discussed.

Interaction of poly(ethylene-glycols) with air-water interfaces and lipid monolayers: investigations on surface pressure and surface potential.

PubMed Central

Winterhalter, M; Bürner, H; Marzinka, S; Benz, R; Kasianowicz, J J

1995-01-01

We have characterized the surface activity of different-sized poly(ethylene-glycols) (PEG; M(r) 200-100,000 Da) in the presence or absence of lipid monolayers and over a wide range of bulk PEG concentrations (10(-8)-10% w/v). Measurements of the surface potential and surface pressure demonstrate that PEGs interact with the air-water and lipid-water interfaces. Without lipid, PEG added either to the subphase or to the air-water interface forms relatively stable monolayers. Except for very low molecular weight polymers (PEGs < 1000 Da), low concentrations of PEG in the subphase (between 10(-5) and 10(-4)% w/v) increase the surface potential from zero (with respect to the potential of a pure air-water interface) to a plateau value of approximately 440 mV. At much higher polymer concentrations, > 10(-1)% (w/v), depending on the molecular weight of the PEG and corresponding to the concentration at which the polymers in solution are likely to overlap, the surface potential decreases. High concentrations of PEG in the subphase cause a similar decrease in the surface potential of densely packed lipid monolayers spread from either diphytanoyl phosphatidylcholine (DPhPC), dipalmitoyl phosphatidylcholine (DPPC), or dioleoyl phosphatidylserine (DOPS). Adding PEG as a monolayer at the air-water interface also affects the surface activity of DPhPC or DPPC monolayers. At low lipid concentration, the surface pressure and potential are determined by the polymer. For intermediate lipid concentrations, the surface pressure-area and surface potential-area isotherms show that the effects due to lipid and PEG are not always additive and that the polymer's effect is distinct for the two lipids. When PEG-lipid-mixed monolayers are compressed to surface pressures greater than the collapse pressure for a PEG monolayer, the surface pressure-area and surface potential-area isotherms approach that of the lipid alone, suggesting that for this experimental condition PEG is expelled from the interface. PMID:8534807

A Proposed Intelligent Policy-Based Interface for a Mobile eHealth Environment

NASA Astrophysics Data System (ADS)

Tavasoli, Amir; Archer, Norm

Users of mobile eHealth systems are often novices, and the learning process for them may be very time consuming. In order for systems to be attractive to potential adopters, it is important that the interface should be very convenient and easy to learn. However, the community of potential users of a mobile eHealth system may be quite varied in their requirements, so the system must be able to adapt easily to suit user preferences. One way to accomplish this is to have the interface driven by intelligent policies. These policies can be refined gradually, using inputs from potential users, through intelligent agents. This paper develops a framework for policy refinement for eHealth mobile interfaces, based on dynamic learning from user interactions.

TRANSIENT DUPUIT INTERFACE FLOW WITH PARTIALLY PENETRATING FEATURES

EPA Science Inventory

A comprehensive potential is presented for Dupuit interface flow in coastal aquifers where both the fresh water and salt water are moving. The resulting potential flow problem may be solved, for incompressible confined aquifers, using analytic functions. The vertical velocity of ...

Polydimethylsiloxane-based optical waveguides for tetherless powering of floating microstimulators

NASA Astrophysics Data System (ADS)

Ersen, Ali; Sahin, Mesut

2017-05-01

Neural electrodes and associated electronics are powered either through percutaneous wires or transcutaneous powering schemes with energy harvesting devices implanted underneath the skin. For electrodes implanted in the spinal cord and the brain stem that experience large displacements, wireless powering may be an option to eliminate device failure by the breakage of wires and the tethering of forces on the electrodes. We tested the feasibility of using optically clear polydimethylsiloxane (PDMS) as a waveguide to collect the light in a subcutaneous location and deliver to deeper regions inside the body, thereby replacing brittle metal wires tethered to the electrodes with PDMS-based optical waveguides that can transmit energy without being attached to the targeted electrode. We determined the attenuation of light along the PDMS waveguides as 0.36±0.03 dB/cm and the transcutaneous light collection efficiency of cylindrical waveguides as 44%±11% by transmitting a laser beam through the thenar skin of human hands. We then implanted the waveguides in rats for a month to demonstrate the feasibility of optical transmission. The collection efficiency and longitudinal attenuation values reported here can help others design their own waveguides and make estimations of the waveguide cross-sectional area required to deliver sufficient power to a certain depth in tissue.

Does sacral pulsed electromagnetic field therapy have a better effect than transcutaneous electrical nerve stimulation in patients with neurogenic overactive bladder?

PubMed

Fergany, Lamyaa A; Shaker, Husain; Arafa, Magdy; Elbadry, Mohamed S

2017-06-01

To compare the effectiveness of pulsed electromagnetic field therapy (PEMFT) and transcutaneous electrical nerve stimulation (TENS) on neurogenic overactive bladder dysfunction (OAB) in patients with spinal cord injury (SCI). In all, 80 patients [50 men and 30 women, with a mean (SD) age of 40.15 (8.76) years] with neurogenic OAB secondary to suprasacral SCI were included. They underwent urodynamic studies (UDS) before and after treatment. Patients were divided into two equal groups: Group A, comprised 40 patients who received 20 min of TENS (10 Hz with a 700 s generated pulse), three times per week for 20 sessions; Group B, comprised 40 patients who received PEMFT (15 Hz with 50% intensity output for 5 s/min for 20 min), three times per week for 20 sessions. In Group B, there was a significant increase in the maximum cystometric capacity ( P  < 0.001), volume at first uninhibited detrusor contraction ( P  < 0.002), and maximum urinary flow rate ( P  < 0.02). The UDS showed that the effects of PEMFT in patients with neurogenic OAB secondary to suprasacral SCI was better than TENS for inducing an inhibitory effect on neurogenic detrusor overactivity.

Comparison of Transcutaneous Electrical Nerve Stimulation and Parasternal Block for Postoperative Pain Management after Cardiac Surgery

PubMed Central

Ozturk, Nilgun Kavrut; Baki, Elif Dogan; Kavakli, Ali Sait; Sahin, Ayca Sultan; Ayoglu, Raif Umut; Karaveli, Arzu; Emmiler, Mustafa; Inanoglu, Kerem; Karsli, Bilge

2016-01-01

Background. Parasternal block and transcutaneous electrical nerve stimulation (TENS) have been demonstrated to produce effective analgesia and reduce postoperative opioid requirements in patients undergoing cardiac surgery. Objectives. To compare the effectiveness of TENS and parasternal block on early postoperative pain after cardiac surgery. Methods. One hundred twenty patients undergoing cardiac surgery were enrolled in the present randomized, controlled prospective study. Patients were assigned to three treatment groups: parasternal block, intermittent TENS application, or a control group. Results. Pain scores recorded 4 h, 5 h, 6 h, 7 h, and 8 h postoperatively were lower in the parasternal block group than in the TENS and control groups. Total morphine consumption was also lower in the parasternal block group than in the TENS and control groups. It was also significantly lower in the TENS group than in the control group. There were no statistical differences among the groups regarding the extubation time, rescue analgesic medication, length of intensive care unit stay, or length of hospital stay. Conclusions. Parasternal block was more effective than TENS in the management of early postoperative pain and the reduction of opioid requirements in patients who underwent cardiac surgery through median sternotomy. This trial is registered with Clinicaltrials.gov number NCT02725229. PMID:27445610

The Parameters of Transcutaneous Electrical Nerve Stimulation Are Critical to Its Regenerative Effects When Applied Just after a Sciatic Crush Lesion in Mice

PubMed Central

Martins Lima, Êmyle; Teixeira Goes, Bruno; Zugaib Cavalcanti, João; Vannier-Santos, Marcos André; Martinez, Ana Maria Blanco; Baptista, Abrahão Fontes

2014-01-01

We investigated the effect of two frequencies of transcutaneous electrical nerve stimulation (TENS) applied immediately after lesion on peripheral nerve regeneration after a mouse sciatic crush injury. The animals were anesthetized and subjected to crushing of the right sciatic nerve and then separated into three groups: nontreated, Low-TENS (4 Hz), and High-TENS (100 Hz). The animals of Low- and High-TENS groups were stimulated for 2 h immediately after the surgical procedure, while the nontreated group was only positioned for the same period. After five weeks the animals were euthanized, and the nerves dissected bilaterally for histological and histomorphometric analysis. Histological assessment by light and electron microscopy showed that High-TENS and nontreated nerves had a similar profile, with extensive signs of degeneration. Conversely, Low-TENS led to increased regeneration, displaying histological aspects similar to control nerves. High-TENS also led to decreased density of fibers in the range of 6–12 μm diameter and decreased fiber diameter and myelin area in the range of 0–2 μm diameter. These findings suggest that High-TENS applied just after a peripheral nerve crush may be deleterious for regeneration, whereas Low-TENS may increase nerve regeneration capacity. PMID:25147807

Use of transcutaneous electrical nerve stimulation for chronic pruritus.

PubMed

Mohammad Ali, Basma Mourad; Hegab, Doaa Salah; El Saadany, Hanan Mohammad

2015-01-01

Pruritus is a distressing symptom in many dermatological as well as systemic conditions, and it is sometimes very chronic and relapsing. Transcutaneous electrical nerve stimulation (TENS) is an inexpensive form of analgesia that could also ameliorate itching. This study aimed to evaluate TENS efficacy in patients with pruritus due to some types of chronic eczema, and in patients with chronic hepatic disease. Ten patients with atopic dermatitis (AD), 20 patients with lichen simplex chronicus (LSC), and 16 patients with chronic liver disease having chronic distressing pruritus received three sessions of TENS weekly for 12 sessions, and the effect on the visual analogue scale (VAS) scores was recorded after 2 weeks of therapy, at treatment end, and after an additional month for follow up. There was a statistically significant decline in the mean VAS score for studied groups at weeks 2 and 4 of therapy compared to baseline, but the improvement was more significant in patients with AD, and LSC (p < 0.001 for both) than in those with chronic liver disease (p < 0.01) who also showed an early re-elevation of VAS score on follow up. TENS therapy holds promise as a palliative, alternative, safe and inexpensive treatment for patients with some chronic pruritic conditions. © 2015 Wiley Periodicals, Inc.

High-Frequency Transcutaneous Peripheral Nerve Stimulation Induces a Higher Increase of Heat Pain Threshold in the Cutaneous Area of the Stimulated Nerve When Confronted to the Neighbouring Areas

PubMed Central

Buonocore, M.; Camuzzini, N.; Cecini, M.; Dalla Toffola, E.

2013-01-01

Background. TENS (transcutaneous electrical nerve stimulation) is probably the most diffused physical therapy used for antalgic purposes. Although it continues to be used by trial and error, correct targeting of paresthesias evoked by the electrical stimulation on the painful area is diffusely considered very important for pain relief. Aim. To investigate if TENS antalgic effect is higher in the cutaneous area of the stimulated nerve when confronted to neighbouring areas. Methods. 10 volunteers (4 males, 6 females) underwent three different sessions: in two, heat pain thresholds (HPTs) were measured on the dorsal hand skin before, during and after electrical stimulation (100 Hz, 0.1 msec) of superficial radial nerve; in the third session HPTs, were measured without any stimulation. Results. Radial nerve stimulation induced an increase of HPT significantly higher in its cutaneous territory when confronted to the neighbouring ulnar nerve territory, and antalgic effect persisted beyond the stimulation time. Conclusions. The location of TENS electrodes is crucial for obtaining the strongest pain relief, and peripheral nerve trunk stimulation is advised whenever possible. Moreover, the present study indicates that continuous stimulation could be unnecessary, suggesting a strategy for avoiding the well-known tolerance-like effect of prolonged TENS application. PMID:24027756

The Effect of Transcutaneous Electrical Nerve Stimulation of Sympathetic Ganglions and Acupuncture Points on Distal Blood Flow.

PubMed

Kamali, Fahimeh; Mirkhani, Hossein; Nematollahi, Ahmadreza; Heidari, Saeed; Moosavi, Elahesadat; Mohamadi, Marzieh

2017-04-01

Transcutaneous electrical nerve stimulation (TENS) is a widely-practiced method to increase blood flow in clinical practice. The best location for stimulation to achieve optimal blood flow has not yet been determined. We compared the effect of TENS application at sympathetic ganglions and acupuncture points on blood flow in the foot of healthy individuals. Seventy-five healthy individuals were randomly assigned to three groups. The first group received cutaneous electrical stimulation at the thoracolumbar sympathetic ganglions. The second group received stimulation at acupuncture points. The third group received stimulation in the mid-calf area as a control group. Blood flow was recorded at time zero as baseline and every 3 minutes after baseline during stimulation, with a laser Doppler flow-meter. Individuals who received sympathetic ganglion stimulation showed significantly greater blood flow than those receiving acupuncture point stimulation or those in the control group (p<0.001). Data analysis revealed that blood flow at different times during stimulation increased significantly from time zero in each group. Therefore, the application of low-frequency TENS at the thoracolumbar sympathetic ganglions was more effective in increasing peripheral blood circulation than stimulation at acupuncture points. Copyright © 2017 Medical Association of Pharmacopuncture Institute. Published by Elsevier B.V. All rights reserved.

Effects of Weight-shifting Exercise Combined with Transcutaneous Electrical Nerve Stimulation on Muscle Activity and Trunk Control in Patients with Stroke.

PubMed

Jung, Kyoung-Sim; Jung, Jin-Hwa; In, Tae-Sung; Cho, Hwi-Young

2016-12-01

This study investigated the effects of weight-shifting exercise (WSE) combined with transcutaneous electrical nerve stimulation (TENS), applied to the erector spinae and external oblique (EO) muscles, on muscle activity and trunk control in patients with hemiparetic stroke. Sixty patients with stroke were recruited to this study and randomly distributed into three treatment groups: (1) WSE + TENS, (2) WSE + placebo TENS, and (3) control. All participants underwent 30 sessions of training (30 minutes five times per week for 6 weeks) and received 1 hour of conventional physical therapy five times per week for 6 weeks. Muscle activity, maximum reaching distance and trunk impairment scale scores were assessed in all patients before and after the training. After training, the WSE + TENS group showed significant increase in the EO activity, maximum reaching distance and trunk impairment scale scores compared with the WSE + placebo TENS and control groups. These findings suggest that WSE with TENS applied to the erector spinae and EO muscles increased the trunk muscle activity and improved trunk control. Therefore, WSE with TENS could be a beneficial intervention in clinical settings for individuals with hemiparetic stroke. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Antihypertensive effect of low-frequency transcutaneous electrical nerve stimulation (TENS) in comparison with drug treatment.

PubMed

Silverdal, Jonas; Mourtzinis, Georgios; Stener-Victorin, Elisabet; Mannheimer, Clas; Manhem, Karin

2012-10-01

Hypertension is a major risk factor for vascular disease, yet blood pressure (BP) control is unsatisfactory low, partly due to side-effects. Transcutaneous electrical nerve stimulation (TENS) is well tolerated and studies have demonstrated BP reduction. In this study, we compared the BP lowering effect of 2.5 mg felodipin once daily with 30 min of bidaily low-frequency TENS in 32 adult hypertensive subjects (mean office BP 152.7/90.0 mmHg) in a randomized, crossover design. Office BP and 24-h ambulatory BP monitoring (ABPM) were performed at baseline and at the end of each 4-week treatment and washout period. Felodipin reduced office BP by 10/6 mmHg (p <0.001 respectively) and after washout BP rose to a level still significantly lower than at baseline. TENS reduced office BP by 5/1.5 mmHg (p <0.01, ns). After TENS washout, BP was further reduced and significantly lower than at baseline, but at levels similar to BP after felodipin washout and therefore reasonably caused by factors other than the treatment per se. ABPM revealed a significant systolic reduction of 3 mmHg by felodipin, but no significant changes were noted after TENS. We conclude that our study does not present any solid evidence of BP reduction of TENS.

Different mechanisms for the short-term effects of real versus sham transcutaneous electrical nerve stimulation (TENS) in patients with chronic pain: a pilot study.

PubMed

Oosterhof, Jan; Wilder-Smith, Oliver H; Oostendorp, Rob A; Crul, Ben J

2012-01-01

Transcutaneous electrical nerve stimulation (TENS) has existed since the early 1970s. However, randomized placebo controlled studies show inconclusive results in the treatment of chronic pain. These results could be explained by assuming that TENS elicits a placebo response. However, in animal research TENS has been found to decrease hyperalgesia, which contradicts this assumption. The aim of this study is to use quantitative sensory testing to explore changes in pain processing during sham versus real TENS in patients with chronic pain. Patients with chronic pain (N = 20) were randomly allocated to real TENS or sham TENS application. Electrical pain thresholds (EPTs) were determined inside and outside the segment stimulated, before and after the first 20 minutes of the intervention, and after a period of 10 days of daily real/sham TENS application. Pain relief did not differ significantly for real versus sham TENS. However, by comparing time courses of EPTs, it was found that EPT values outside the segment of stimulation increased for sham TENS, whereas for real TENS these values decreased. There were, however, no differences for EPT measurements inside the segment stimulated. These results illustrate the importance of including mechanism-reflecting parameters in addition to symptoms when conducting pain research.

Effects of transcutaneous electrical nerve stimulation on pain, walking function, respiratory muscle strength and vital capacity in kidney donors: a protocol of a randomized controlled trial

PubMed Central

2013-01-01

Background Pain is a negative factor in the recovery process of postoperative patients, causing pulmonary alterations and complications and affecting functional capacity. Thus, it is plausible to introduce transcutaneous electrical nerve stimulation (TENS) for pain relief to subsequently reduce complications caused by this pain in the postoperative period. The objective of this paper is to assess the effects of TENS on pain, walking function, respiratory muscle strength and vital capacity in kidney donors. Methods/design Seventy-four patients will be randomly allocated into 2 groups: active TENS or placebo TENS. All patients will be assessed for pain intensity, walk function (Iowa Gait Test), respiratory muscle strength (maximal inspiratory pressure and maximal expiratory pressure) and vital capacity before and after the TENS application. The data will be collected by an assessor who is blinded to the group allocation. Discussion This study is the first to examine the effects of TENS in this population. TENS during the postoperative period may result in pain relief and improvements in pulmonary tests and mobility, thus leading to an improved quality of life and further promoting organ donation. Trial registration Registro Brasileiro de Ensaios Clinicos (ReBEC), number RBR-8xtkjp. PMID:23311705

Generation of human-to-pig chimerism to induce tolerance through transcutaneous in utero injection of cord blood-derived mononuclear cells or human bone marrow mesenchymals cells in a preclinical program of liver xenotransplantation: preliminary results.

PubMed

Abellaneda, J M; Ramis, G; Martínez-Alarcón, L; Majado, M J; Quereda, J J; Herrero-Medrano, J M; Mendonça, L; García-Nicolás, O; Reus, M; Insausti, C; Ríos, A; López-Navas, A; González, M R; Pallarés, F J; Munoz, A; Ramírez, P; Parrilla, P

2012-01-01

Using a percutaneous ecoguided injection system to obtain chimeric piglets through a less invasive and traumatic technique than previously reported. The two types of human cells included umbilical cord blood mononuclear elements and mesenchymal stem cells cultured from bone marrow. Four sows at gestational day 50 were anesthetized. A needle was inserted through the skin and uterine wall to reach the peritoneal cavity of the fetuses under continuous ultrasound guidance. Fourteen piglets were injected with various cell concentrations. All sows carried pregnancies to term yielding 69 piglets, among which 67 were alive and two mummified. Two piglets died during the first 48 hours of life. Chimerism was detected using flow cytometry and by quantitative polymerase chain reaction (q-PCR) to detect Alu gene in blood or tissues samples. The analysis detected blood chimerism in 13 piglets (21%) by flow cytometry and the presence of the human Alu gene in 33 (51%) by q-PCR. The results suggest cell trafficking between littermates after in utero injection. Transcutaneous echo-guided injection succeeded to produce chimeric piglets without disadvantages to the sow or the fetuses and avoiding abortions or fetal death. Copyright © 2012 Elsevier Inc. All rights reserved.

Transcutaneous vagus nerve stimulation (tVNS) enhances divergent thinking.

PubMed

Colzato, Lorenza S; Ritter, Simone M; Steenbergen, Laura

2018-03-01

Creativity is one of the most important cognitive skills in our complex and fast-changing world. Previous correlative evidence showed that gamma-aminobutyric acid (GABA) is involved in divergent but not convergent thinking. In the current study, a placebo/sham-controlled, randomized between-group design was used to test a causal relation between vagus nerve and creativity. We employed transcutaneous vagus nerve stimulation (tVNS), a novel non-invasive brain stimulation technique to stimulate afferent fibers of the vagus nerve and speculated to increase GABA levels, in 80 healthy young volunteers. Creative performance was assessed in terms of divergent thinking (Alternate Uses Task) and convergent thinking tasks (Remote Associates Test, Creative Problem Solving Task, Idea Selection Task). Results demonstrate active tVNS, compared to sham stimulation, enhanced divergent thinking. Bayesian analysis reported the data to be inconclusive regarding a possible effect of tVNS on convergent thinking. Therefore, our findings corroborate the idea that the vagus nerve is causally involved in creative performance. Even thought we did not directly measure GABA levels, our results suggest that GABA (likely to be increased in active tVNS condition) supports the ability to select among competing options in high selection demand (divergent thinking) but not in low selection demand (convergent thinking). Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Anthrax vaccine antigen-adjuvant formulations completely protect New Zealand white rabbits against challenge with Bacillus anthracis Ames strain spores.

PubMed

Peachman, Kristina K; Li, Qin; Matyas, Gary R; Shivachandra, Sathish B; Lovchik, Julie; Lyons, Rick C; Alving, Carl R; Rao, Venigalla B; Rao, Mangala

2012-01-01

In an effort to develop an improved anthrax vaccine that shows high potency, five different anthrax protective antigen (PA)-adjuvant vaccine formulations that were previously found to be efficacious in a nonhuman primate model were evaluated for their efficacy in a rabbit pulmonary challenge model using Bacillus anthracis Ames strain spores. The vaccine formulations include PA adsorbed to Alhydrogel, PA encapsulated in liposomes containing monophosphoryl lipid A, stable liposomal PA oil-in-water emulsion, PA displayed on bacteriophage T4 by the intramuscular route, and PA mixed with Escherichia coli heat-labile enterotoxin administered by the needle-free transcutaneous route. Three of the vaccine formulations administered by the intramuscular or the transcutaneous route as a three-dose regimen induced 100% protection in the rabbit model. One of the formulations, liposomal PA, also induced significantly higher lethal toxin neutralizing antibodies than PA-Alhydrogel. Even 5 months after the second immunization of a two-dose regimen, rabbits vaccinated with liposomal PA were 100% protected from lethal challenge with Ames strain spores. In summary, the needle-free skin delivery and liposomal formulation that were found to be effective in two different animal model systems appear to be promising candidates for next-generation anthrax vaccine development.

Pain relief by transcutaneous electric nerve stimulation with bidirectional modulated sine waves in patients with chronic back pain: a randomized, double-blind, sham-controlled study.

PubMed

Shimoji, Koki; Takahashi, Norio; Nishio, Yasuyuki; Koyanagi, Mika; Aida, Sumihisa

2007-01-01

Objectives.  Newly developed bidirectional modulated sine waves (BMW) might provide some derived benefit to patients with low back pain. Pain relief by transcutaneous electric nerve stimulation (TENS) with BMWs was tested. Materials and Methods.  Analgesic effects of BMWs and conventional bidirectional pulsed waves on chronic back pain in 28 patients were compared, and effects of repeated TENS using BMWs on chronic back pain were investigated in 21 patients by means of a randomized double-blind, sham-controlled, parallel-group method. Pain intensity was assessed using numerical rating scale (NRS). Results.  There was significant immediate reduction in NRS in patients receiving BMWs, and 60 min after treatment compared to sham TENS. Weekly repeated treatments using massage and TENS with BMWs for 5 weeks resulted in a decrease of NRS, but there were no significant differences between the TENS plus massage and sham TENS plus massage groups. Conclusions.  This study shows that TENS with BMWs significantly inhibits chronic back pain, and treatment effects are attained within a day. The results also suggest that there were no statistically significant long-term effects of TENS with BMW in the repeated treatment.

Transcutaneous electrical nerve stimulation improves low back pain during pregnancy.

PubMed

Keskin, E A; Onur, O; Keskin, H L; Gumus, I I; Kafali, H; Turhan, N

2012-01-01

To compare the efficiency of transcutaneous electrical nerve stimulation (TENS) with those of exercise and acetaminophen for the treatment of pregnancy-related low back pain (LBP) during the third trimester of pregnancy. This prospective study included 79 subjects (≥32 gestational weeks) with visual analog scale (VAS) pain scores ≥5. Participants were divided randomly into a control group (n = 21) and three treatment groups [exercise (n = 19); acetaminophen (n = 19); TENS (n = 20)]. The VAS and the Roland-Morris disability questionnaire (RMDQ) were completed before and 3 weeks after treatment to assess the impact of pain on daily activities. During the study period, pain intensity increased in 57% of participants in the control group, whereas pain decreased in 95% of participants in the exercise group and in all participants in the acetaminophen and TENS groups. Post-treatment VAS and RMDQ values were significantly lower in the treatment groups (p < 0.001). VAS and RMDQ scores indicated a significantly greater degree of pain relief in the TENS group than in the exercise and acetaminophen groups (p < 0.001). No adverse effect of TENS application on pregnant women was observed during the study. TENS is an effective and safe treatment modality for LBP during pregnancy. TENS improved LBP more effectively than did exercise and acetaminophen. Copyright © 2012 S. Karger AG, Basel.

Comparison of transcutaneous contrast-enhanced ultrasound-guided injected hemostatic agents with traditional surgery treatment for liver, spleen and kidney trauma: a retrospective study.

PubMed

Wang, Dong; Lv, Faqin; Luo, Yukun; An, Lichun; Li, Junlai; Xie, Xia; Tian, Jiangke; Zhao, Weiyan; Tang, Jie

2012-10-01

There is lack of studies on the effectiveness of transcutaneous contrast-enhanced ultrasound-guided injections of hemostatic agents for liver. spleen and kidney trauma. We compared treatment by hemostatic agents to surgical treatment in a retrospective interventional human study. The study enrolled a total of 135 subjects from emergency unit of the Chinese People's Liberation Army General Hospital in Beijing. Within the cohort, 62 patients received contrast enhanced ultrasound-guided injection of hemostatic agents and the rest received surgical treatments. The injury severity score was lower in the hemostatic agent treatment group than surgical treatment group (p<0.05), but Glasgow coma scale scores did not reach statistical significance. The patients in the surgical treatment group had significantly higher hospital fees than those in the hemostatic treatment group (p<0.05), although the length of hospitalization did not significantly differ between two groups. Safety outcome variables pre- and post-treatment remained within normal limits in both groups. Hemostatic agents were more cost-effective than surgery to treat patients with liver, spleen and kidney trauma. However, given the limited sample size, subsequent studies drawing upon larger populations from multiple medical centers are necessary for follow-up.

Simultaneous backward data transmission and power harvesting in an ultrasonic transcutaneous energy transfer link employing acoustically dependent electric impedance modulation.

PubMed

Ozeri, Shaul; Shmilovitz, Doron

2014-09-01

The advancement and miniaturization of body implanted medical devices pose several challenges to Ultrasonic Transcutaneous Energy Transfer (UTET), such as the need to reduce the size of the piezoelectric resonator, and the need to maximize the UTET link power-transfer efficiency. Accordingly, the same piezoelectric resonator that is used for energy harvesting at the body implant, may also be used for ultrasonic backward data transfer, for instance, through impedance modulation. This paper presents physical considerations and design guidelines of the body implanted transducer of a UTET link with impedance modulation for a backward data transfer. The acoustic matching design procedure was based on the 2×2 transfer matrix chain analysis, in addition to the Krimholtz Leedom and Matthaei KLM transmission line model. The UTET power transfer was carried out at a frequency of 765 kHz, continuous wave (CW) mode. The backward data transfer was attained by inserting a 9% load resistance variation around its matched value (550 Ohm), resulting in a 12% increase in the acoustic reflection coefficient. A backward data transmission rate of 1200 bits/s was experimentally demonstrated using amplitude shift keying, simultaneously with an acoustic power transfer of 20 mW to the implant. Copyright © 2014 Elsevier B.V. All rights reserved.

Hydration Effects on Skin Microstructure as Probed by High-Resolution Cryo-Scanning Electron Microscopy and Mechanistic Implications to Enhanced Transcutaneous Delivery of Biomacromolecules

PubMed Central

Tan, Grace; Xu, Peng; Lawson, Louise B.; He, Jibao; Freytag, Lucia C.; Clements, John D.; John, Vijay T.

2010-01-01

Although hydration is long known to improve the permeability of skin, penetration of macromolecules such as proteins is limited and the understanding of enhanced transport is based on empirical observations. This study uses high-resolution cryo-scanning electron microscopy to visualize microstructural changes in the stratum corneum (SC) and enable a mechanistic interpretation of biomacromolecule penetration through highly hydrated porcine skin. Swollen corneocytes, separation of lipid bilayers in the SC intercellular space to form cisternae, and networks of spherical particulates are observed in porcine skin tissue hydrated for a period of 4–10 h. This is explained through compaction of skin lipids when hydrated, a reversal in the conformational transition from unilamellar liposomes in lamellar granules to lamellae between keratinocytes when the SC skin barrier is initially established. Confocal microscopy studies show distinct enhancement in penetration of fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) through skin hydrated for 4–10 h, and limited penetration of FITC-BSA once skin is restored to its natively hydrated structure when exposed to the environment for 2–3 h. These results demonstrate the effectiveness of a 4–10 h hydration period to enhance transcutaneous penetration of large biomacromolecules without permanently damaging the skin. PMID:19582754

An alternative therapy for drug-resistant epilepsy: transcutaneous auricular vagus nerve stimulation.

PubMed

Rong, Peijing; Liu, Aihua; Zhang, Jianguo; Wang, Yuping; Yang, Anchao; Li, Liang; Ben, Hui; Li, Liping; Liu, Rupeng; He, Wei; Liu, Huanguang; Huang, Feng; Li, Xia; Wu, Peng; Zhu, Bing

2014-01-01

Previous studies demonstrated that vagus nerve stimulation (VNS) is an effective therapy for drug-resistant epilepsy. Acupuncture is also used to treat epilepsy. This study was designed to examine the safety and effectiveness of transcutaneous auricular vagus nerve stimulation (ta-VNS) for patients with drug-resistant epilepsy. A total of 50 volunteer patients with drug-resistant epilepsy were selected for a random clinical trial to observe the therapeutic effect of ta-VNS. The seizure frequency, quality of life, and severity were assessed in weeks 8, 16, and 24 of the treatment according to the percentage of seizure frequency reduction. In the pilot study, 47 of the 50 epilepsy patients completed the 24-week treatment; three dropped off. After 8-week treatment, six of the 47 patients (12%) were seizure free and 12 (24%) had a reduction in seizure frequency. In week 16 of the continuous treatment, six of the 47 patients (12%) were seizure free; 17 (34%) had a reduction in seizure frequency. After 24 weeks' treatment, eight patients (16%) were seizure free; 19 (38%) had reduced seizure frequency. Similar to the therapeutic effect of VNS, ta-VNS can suppress epileptic seizures and is a safe, effective, economical, and widely applicable treatment option for drug-resistant epilepsy. (ChiCTR-TRC-10001023).

Analysis of current density and specific absorption rate in biological tissue surrounding transcutaneous transformer for an artificial heart.

PubMed

Shiba, Kenji; Nukaya, Masayuki; Tsuji, Toshio; Koshiji, Kohji

2008-01-01

This paper reports on the current density and specific absorption rate (SAR) analysis of biological tissue surrounding an air-core transcutaneous transformer for an artificial heart. The electromagnetic field in the biological tissue is analyzed by the transmission line modeling method, and the current density and SAR as a function of frequency, output voltage, output power, and coil dimension are calculated. The biological tissue of the model has three layers including the skin, fat, and muscle. The results of simulation analysis show SARs to be very small at any given transmission conditions, about 2-14 mW/kg, compared to the basic restrictions of the International Commission on nonionizing radiation protection (ICNIRP; 2 W/kg), while the current density divided by the ICNIRP's basic restrictions gets smaller as the frequency rises and the output voltage falls. It is possible to transfer energy below the ICNIRP's basic restrictions when the frequency is over 250 kHz and the output voltage is under 24 V. Also, the parts of the biological tissue that maximized the current density differ by frequencies; in the low frequency is muscle and in the high frequency is skin. The boundary is in the vicinity of the frequency 600-1000 kHz.

Optical investigation of variability in body region dependent transcutaneous oxygen saturation

NASA Astrophysics Data System (ADS)

Philimon, Sheena P.; Huong, Audrey K. C.; Hafizah, W. M.; Ong, P. E.; Ngu, Xavier T. I.

2016-11-01

This paper presents the use of multispectral imaging system to investigate variability in transcutaneous oxygen saturation (StO2) amongst different individuals and at different skin sites. Noncontact reflectance data are collected from central forehead, posterior forearm, thenar region of palm and proximal ankle of three healthy Asians. The prediction of the required StO2 value is via fitting Extended Modified Lambert (EMLB) model to the measured attenuation data using extinction coefficient of hemoglobin components in the wavelength range of 520 - 600 nm as its priori knowledge. The obtained results revealed a relatively high mean StO2 of 54 ± 1.9% at the palm of the hand site. This is followed by measurement at foot ankle and forehead with StO2 of 52.3 ± 2.4% and 51.2 ± 7.7%, respectively. Meanwhile the lowest reading of StO2 of 48.8 ± 5.1% is observed at the posterior forearm. Based on these findings, this work concluded that palm of the hand would provide considerably consistent measurement of StO2 among individuals. This is largely owing to the higher density of circulatory anastomosis at this skin site. This implied viability of using the developed strategy in the studies of microcirculation mechanism especially on wound at this skin region.

Progress in the development of a transcutaneously powered axial flow blood pump ventricular assist system.

PubMed

Parnis, S M; Conger, J L; Fuqua, J M; Jarvik, R K; Inman, R W; Tamez, D; Macris, M P; Moore, S; Jacobs, G; Sweeney, M J; Frazier, O H

1997-01-01

Development of the Jarvik 2000 intraventricular assist system for long-term support is ongoing. The system integrates the Jarvik 2000 axial flow blood pump with a microprocessor based automatic motor controller to provide response to physiologic demands. Nine devices have been evaluated in vivo (six completed, three ongoing) with durations in excess of 26 weeks. Instrumented experiments include implanted transit-time ultrasonic flow probes and dual micromanometer LV/AoP catheters. Treadmill exercise and heart pacing studies are performed to evaluate control system response to increased heart rates. Pharmacologically induced cardiac dysfunction studies are performed in awake and anesthetized calves to demonstrate control response to simulated heart failure conditions. No deleterious effects or events were encountered during any physiologic studies. No hematologic, renal, hepatic, or pulmonary complications have been encountered in any study. Plasma free hemoglobin levels of 7.0 +/- 5.1 mg/dl demonstrate no device related hemolysis throughout the duration of all studies. Pathologic analysis at explant showed no evidence of thromboembolic events. All pump surfaces were free of thrombus except for a minimal ring of fibrin, (approximately 1 mm) on the inflow bearing. Future developments for permanent implantation will include implanted physiologic control systems, implanted batteries, and transcutaneous energy and data transmission systems.

Hyperbaric nitrogen prolongs breath-holding time in humans.

PubMed

Morooka, H; Wakasugi, Y; Shimamoto, H; Shibata, O; Sumikawa, K

2000-09-01

Either an increase in PaCO(2) or a decrease in PaO(2), can affect respiratory stimulation through respiratory centers, thus influencing breath-holding time (BHT). This study was designed to determine whether and how hyperbaric air could influence BHT in comparison with hyperbaric oxygen in humans. We studied 36 healthy volunteers in a multiplace hyperbaric chamber. BHT, pulse oximeter, and transcutaneous carbon dioxide tension were measured at 1 and 2.8 atmosphere absolute (ATA) in two groups. Group A (n = 20) breathed air. Group O (n = 16) breathed oxygen with a face mask (5 L/min). BHTs were 108 +/- 28 s at 1.0 ATA and 230 +/- 71 s at 2.8 ATA in Group A, and 137 +/- 48 s at 1.0 ATA and 180 +/- 52 s at 2.8 ATA in Group O. Transcutaneous carbon dioxide tension in Group A (59 +/- 2 mm Hg) was higher than that in Group O (54 +/- 2 mm Hg) at the end of maximal breath-holding at 2.8 ATA. The prolongation of BHT in hyperbaric air is significantly greater than that in hyperbaric oxygen. Breath-holding time is significantly prolonged in hyperbaric air than it is in hyperbaric oxygen. The mechanism involves the anesthetic effect of nitrogen suppressing the suffocating feeling during breath-holding.

[Physiology and pathology of reproduction in domesticated New World camelids with special emphasis on ultrasonography].

PubMed

Hoops, M; Kauffold, J

2013-01-01

The number of New World camelids in Germany is increasing. Owners and breeders are usually well educated regarding their animals. For practitioners, this means being up-to-date with respect to their veterinary knowledge. This includes the physiology and pathology of reproduction. Specifics of reproduction in domesticated New World camelids are an induced ovulation, the absence of cyclic sexual activity, a relatively long gestation of 336-349 days and a predominantly left-horn gestation. Ultrasonography plays an important role as part of the gynecological examination. Generally, the ultrasonographic examination can be performed transrectally and transcutaneously in the left or right flanks. Transrectal ultrasonography has to be carried out with particular caution to avoid rectal injuries. An accurate pregnancy diagnosis by transrectal scanning is possible starting from day 20 of pregnancy; using transcutaneous scanning, diagnosis is accurate starting on days 50-60 (left flank) or from day 90 (right flank) of pregnancy, respectively. Ultrasonography is also appropriate to examine the non-gravid uterus and the ovaries. Based on 5 years of experience working with farmed New World camelids, the article describes the physiology and pathology of reproduction in domesticated New World camelids. Particular consideration is given to the ultrasonographical examination of the genital organs.

Nano interface potential influences in CdTe quantum dots and biolabeling

NASA Astrophysics Data System (ADS)

Kanagasubbulakshmi, S.; Kadirvelu, K.

2018-05-01

Nano interface influences in physiochemical properties of quantum dots (QDs) are the challenging approach to tailor its surface functionalities. In this study, a set of polar and non-polar solvents were selected to analyze the influences in solvent-based dynamic radius and surface potential of QDs. From the nano interface chemistry of polar and non-polar solvents, an appropriate mechanism of precipitation and hydrophobic ligand exchange strategy were elucidated by correlating Henry's equation. Further, the in vitro cytotoxic potential and antimicrobial activity of QDs were assessed to perform biolabeling. From the observations, an appropriate dosage of QDs was fixed to label the animal ((RAW 264.7 cell lines) and bacterial cells (Escherichia coli) for effective cell attachment. Biolabeling was achieved by tailoring nano interface chemistry of QDs without additional support of biomolecules. Bacterial cell wall-based interaction of QDs was evaluated using SEM and EDAX analysis. Thus, provided clear insights into the nano interface chemistry in the development of highly photostable QDs will be helpful in biomedical applications.

Surface tension and long range corrections of cylindrical interfaces

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

Bourasseau, E.; Malfreyt, P.; Ghoufi, A., E-mail: aziz.ghoufi@univ-rennes1.fr

2015-12-21

The calculation of the surface tension of curved interfaces has been deeply investigated from molecular simulation during this last past decade. Recently, the thermodynamic Test-Area (TA) approach has been extended to the calculation of surface tension of curved interfaces. In the case of the cylindrical vapour-liquid interfaces of water and Lennard-Jones fluids, it was shown that the surface tension was independent of the curvature of the interface. In addition, the surface tension of the cylindrical interface is higher than that of the planar interface. Molecular simulations of cylindrical interfaces have been so far performed (i) by using a shifted potential,more » (ii) by means of large cutoff without periodic boundary conditions, or (iii) by ignoring the long range corrections to the surface tension due to the difficulty to estimate them. Indeed, unlike the planar interfaces there are no available operational expressions to consider the tail corrections to the surface tension of cylindrical interfaces. We propose here to develop the long range corrections of the surface tension for cylindrical interfaces by using the non-exponential TA (TA2) method. We also extend the formulation of the Mecke-Winkelmann corrections initially developed for planar surfaces to cylindrical interfaces. We complete this study by the calculation of the surface tension of cylindrical surfaces of liquid tin and copper using the embedded atom model potentials.« less

Micromachined three-dimensional electrode arrays for transcutaneous nerve tracking

NASA Astrophysics Data System (ADS)

Rajaraman, Swaminathan; Bragg, Julian A.; Ross, James D.; Allen, Mark G.

2011-08-01

We report the development of metal transfer micromolded (MTM) three-dimensional microelectrode arrays (3D MEAs) for a transcutaneous nerve tracking application. The measurements of electrode-skin-electrode impedance (ESEI), electromyography (EMG) and nerve conduction utilizing these minimally invasive 3D MEAs are demonstrated in this paper. The 3D MEAs used in these measurements consist of a metalized micro-tower array that can penetrate the outer layers of the skin in a painless fashion and are fabricated using MTM technology. Two techniques, an inclined UV lithography approach and a double-side exposure of thick negative tone resist, have been developed to fabricate the 3D MEA master structure. The MEAs themselves are fabricated from the master structure utilizing micromolding techniques. Metal patterns are transferred during the micromolding process, thereby ensuring reduced process steps compared to traditional silicon-based approaches. These 3D MEAs have been packaged utilizing biocompatible Kapton® substrates. ESEI measurements have been carried out on test human subjects with standard commercial wet electrodes as a reference. The 3D MEAs demonstrate an order of magnitude lower ESEI (normalized to area) compared to wet electrodes for an area that is 12.56 times smaller. This compares well with other demonstrated approaches in literature. For a nerve tracking demonstration, we have chosen EMG and nerve conduction measurements on test human subjects. The 3D MEAs show 100% improvement in signal power and SNR/√area as compared to standard electrodes. They also demonstrate larger amplitude signals and faster rise times during nerve conduction measurements. We believe that this microfabrication and packaging approach scales well to large-area, high-density arrays required for applications like nerve tracking. This development will increase the stimulation and recording fidelity of skin surface electrodes, while increasing their spatial resolution by an order of magnitude or more. Although biopotential electrode systems are not without their challenges, the non-invasive access to neural information, along with the potential for automation with associated electronic and software development, is precisely what makes this technology an excellent candidate for the next generation in diagnostic, therapeutic, and prosthetic devices.

Transcutaneous electrical nerve stimulation for postoperative pain relief after arthroscopic rotator cuff repair: a prospective double-blinded randomized trial.

PubMed

Mahure, Siddharth A; Rokito, Andrew S; Kwon, Young W

2017-09-01

Arthroscopic rotator cuff repair (ARCR) can be associated with significant postoperative pain. Concern for opioid abuse has led surgeons to identify alternative, efficacious methods of postoperative analgesia. To determine whether transcutaneous electrical nerve stimulation (TENS) can have a similarly beneficial effect after shoulder procedures, we conducted a prospective double-blinded randomized trial in patients undergoing outpatient ARCR. All patients undergoing ARCR of a full-thickness rotator cuff tear by the senior authors were identified. Patients with a history of recent narcotic use or prior narcotic abuse and those under management of a pain control specialist were excluded. Patients were randomized into 2 groups, active or placebo TENS, and used the device for 4 sessions/day for 45 minutes/session for the first postoperative week. All patients received Percocet 5/325 mg (oxycodone/acetaminophen) for use as rescue pain pills. One-week narcotic consumption and visual analog scale pain scores were compared between groups. The final analysis included 37 patients (21 active,16 placebo). Baseline and procedural differences were not different between groups. At 1 week postoperatively, patients in the active group had significantly lower pain scores (3.6 ± 2.1 vs. 5.8 ± 1.2; P= .008). Postoperative Percocet consumption during the initial 48 hours (12.8 ± 4.7 vs. 17.2 ± 6.3; P = .020) and during the first week (25.2 ± 9.9 vs. 33.8 ± 14.3; P = .037) was also significantly lower in the active group. Results from this prospective double-blinded randomized trial demonstrate that compared with placebo TENS, active TENS can result in significantly less pain and reduced opioid use in the immediate postoperative period after ARCR, suggesting that TENS may be potentially useful in a multimodal approach to managing postoperative pain. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Decreased Opioid Utilization and Cost at One Year in Chronic Low Back Pain Patients Treated with Transcutaneous Electric Nerve Stimulation (TENS).

PubMed

Pivec, Robert; Minshall, Michael E; Mistry, Jaydev B; Chughtai, Morad; Elmallah, Randa K; Mont, Michael A

2015-11-01

Chronic low back pain (CLBP) may be treated without opioids through the use of transcutaneous electrical nerve stimulation (TENS). However, no study has evaluated its clinical effect and economic impact as measured by opioid utilization and costs. The purpose of this study was to evaluate patients who were given TENS for CLBP compared to a matched group without TENS at one-year follow-up, to determine differences between opioid consumption. Opioid utilization and costs in patients who did and did not receive TENS were extracted from a Medicare supplemental administrative claims database. Patients were selected if they had at least two ICD-9-CM coded claims for low back pain in a three-month period and were then propensity score matched at a 1:1 ratio between patients who received TENS and those who did not. There were 22,913 patients in each group who had a minimum follow-up of one year. There were no significant demographic or comorbidity differences with the exception that TENS patients had more episodes of back pain. Significantly fewer patients in the TENS group required opioids at final follow-up (57.7 vs. 60.3%). TENS patients also had significantly fewer annual per-patient opioid costs compared to non-TENS patients ($169 vs. $192). There were significantly lower event rates in TENS patients compared to non-TENS patients when measured by opioid utilization (characterized by frequency of prescription refills) (3.82 vs. 4.08, respectively) or pharmacy utilization (31.67 vs. 32.25). The TENS group also demonstrated a significantly lower cost of these utilization events ($44 vs. $49) and avoided more opioid events (20.4 events fewer per 100 patients annually). Treatment of CLBP with TENS demonstrated significantly fewer patients requiring opioids, fewer events where a patient required an opioid prescription, and lower per-patient costs. Since TENS is both non-invasive and a non-narcotic, it may potentially allow physicians to be more aggressive in treating CLBP patients.

Effect of Unmodulated 5-kHz Alternating Currents Versus Transcutaneous Electrical Nerve Stimulation on Mechanical and Thermal Pain, Tactile Threshold, and Peripheral Nerve Conduction: A Double-Blind, Placebo-Controlled Crossover Trial.

PubMed

Avendaño-Coy, Juan; Gómez-Soriano, Julio; Goicoechea-García, Carlos; Basco-López, Julian Angel; Taylor, Julian

2017-05-01

To investigate the effect of unmodulated 5-kHz alternating current on mechanical pain threshold (MPT), heat pain threshold (HPT), tactile threshold (TT), and peripheral nerve conduction (PNC) compared with transcutaneous electrical nerve stimulation (TENS) and sham stimulation. National referral center. Randomized, double-blind, placebo-controlled crossover trial. Healthy volunteers (N=38). No dropouts or adverse events were reported. TENS, unmodulated 5-kHz currents, and sham stimulation were applied on the radial nerve for 20 minutes with a 24-hour washout period between them and concealed intervention allocation. Four measures were taken: before, during, and 2 after the interventions. Algometry was used to assess MPT, a Peltier thermode for HPT using the method of limits, Von Frey filaments for TT, and radial nerve compound action potential. No differences were observed on MPT, HPT, and PNC when 5-kHz current and TENS were compared. However, TT increased 56.2mN (95% confidence interval [CI], 28.8-83.6) in the TENS group compared with the 5-kHz current group during intervention. Compared with sham stimulation during intervention, MPT increased 4.7N (95% CI, 0.3-9.2) using 5-kHz current and 10.4N (95% CI, 3.5-17.3) with TENS. TT increased 17.2mN (95% CI, 4.7-29.7) with 5-kHz current and 73.4mN (95% CI, 47.5-99.2) with TENS. However, HPT increased 1.0°C (95% CI, 0.2-2.0) only with TENS. For the PNC, no differences were found among the 3 groups. Unmodulated 5-kHz current produced an increase in somatosensory thresholds that was greater than placebo but not when compared with TENS; however, participants perceived 5-kHz currents to be more comfortable and showed more habituation to them. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Skin vaccination via fractional infrared laser ablation - Optimization of laser-parameters and adjuvantation.

PubMed

Scheiblhofer, Sandra; Strobl, Anna; Hoepflinger, Veronika; Thalhamer, Theresa; Steiner, Martin; Thalhamer, Josef; Weiss, Richard

2017-03-27

Methods to deliver an antigen into the skin in a painless, defined, and reproducible manner are essential for transcutaneous immunization (TCI). Here, we employed an ablative fractional infrared laser (P.L.E.A.S.E. Professional) to introduce clinically relevant vaccines into the skin. To elicit the highest possible antibody titers with this system, we optimized different laser parameters, such as fluence and pore number per area, and tested various adjuvants. BALB/c mice were immunized with Hepatitis B surface antigen (HBsAg) by laser-microporation. Adjuvants used were alum, CRM 197 , monophosphoryl lipid A, heat-labile enterotoxin subunit B of E. coli (LT-B), and CpG ODN1826. The influence of different fluences (2.1 to 16.8J/cm 2 ) and pore densities (5-15%) was investigated. Furthermore, immunogenicity of HBsAg and the commercially available conjugate vaccines ActHIB® and Menveo® applied via TCI was compared to standard i.m. injection. Antigen-specific antibody titers were assessed by luminometric ELISA. Antibody titers against HBsAg were dependent on pore depth and peaked at a fluence of 8.4J/cm 2 . Immunogenicity was independent of pore density. Adjuvantation with alum significantly reduced antibody titers after TCI, whereas other adjuvants only induced marginal changes in total IgG titers. LT-B and CpG shifted the polarization of the immune response as indicated by decreased IgG1/IgG2a ratios. HBsAg/LT-B applied via TCI induced similar antibody titers compared to i.m. injection of HBsAg/alum. In contrast to i.m. injection, we observed a dose response from 5 to 20μg after TCI. Both, ActHIB® and Menveo® induced high antibody titers after TCI, which were comparable to i.m. injection. Alum, the most commonly used adjuvant, is contraindicated for transcutaneous vaccination via laser-generated micropores. TCI with optimized laser parameters induces high antibody titers, which cannot be significantly increased by the tested adjuvants. Commercially available vaccines formulated without alum have the potential for successful TCI via laser-generated micropores, without the need for reformulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

GOM-Face: GKP, EOG, and EMG-based multimodal interface with application to humanoid robot control.

PubMed

Nam, Yunjun; Koo, Bonkon; Cichocki, Andrzej; Choi, Seungjin

2014-02-01

We present a novel human-machine interface, called GOM-Face , and its application to humanoid robot control. The GOM-Face bases its interfacing on three electric potentials measured on the face: 1) glossokinetic potential (GKP), which involves the tongue movement; 2) electrooculogram (EOG), which involves the eye movement; 3) electromyogram, which involves the teeth clenching. Each potential has been individually used for assistive interfacing to provide persons with limb motor disabilities or even complete quadriplegia an alternative communication channel. However, to the best of our knowledge, GOM-Face is the first interface that exploits all these potentials together. We resolved the interference between GKP and EOG by extracting discriminative features from two covariance matrices: a tongue-movement-only data matrix and eye-movement-only data matrix. With the feature extraction method, GOM-Face can detect four kinds of horizontal tongue or eye movements with an accuracy of 86.7% within 2.77 s. We demonstrated the applicability of the GOM-Face to humanoid robot control: users were able to communicate with the robot by selecting from a predefined menu using the eye and tongue movements.

Using Grand Canonical Monte Carlo Simulations to Understand the Role of Interfacial Fluctuations on Solvation at the Water-Vapor Interface.

PubMed

Rane, Kaustubh; van der Vegt, Nico F A

2016-09-15

The present work investigates the effect of interfacial fluctuations (predominantly capillary wave-like fluctuations) on the solvation free energy (Δμ) of a monatomic solute at the water-vapor interface. We introduce a grand-canonical-ensemble-based simulation approach that quantifies the contribution of interfacial fluctuations to Δμ. This approach is used to understand how the above contribution depends on the strength of dispersive and electrostatic solute-water interactions at the temperature of 400 K. At this temperature, we observe that interfacial fluctuations do play a role in the variation of Δμ with the strength of the electrostatic solute-water interaction. We also use grand canonical simulations to further investigate how interfacial fluctuations affect the propensity of the solute toward the water-vapor interface. To this end, we track a quantity called the interface potential (surface excess free energy) with the number of water molecules. With increasing number of water molecules, the liquid-vapor interface moves across a solute, which is kept at a fixed position in the simulation. Hence, the dependence of the interface potential on the number of waters models the process of moving the solute through the water-vapor interface. We analyze the change of the interface potential with the number of water molecules to explain that solute-induced changes in the interfacial fluctuations, like the pinning of capillary-wave-like undulations, do not play any role in the propensity of solutes toward water-vapor interfaces. The above analysis also shows that the dampening of interfacial fluctuations accompanies the adsorption of any solute at the liquid-vapor interface, irrespective of the chemical nature of the solute and solvent. However, such a correlation does not imply that dampening of fluctuations causes adsorption.

Interface Structure, Band Alignment, and Built-In Potentials at LaFeO 3 / n - SrTiO 3 Heterojunctions

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

Comes, Ryan; Chambers, Scott

We demonstrate that LaFeO 3/n-SrTiO 3(001) heterojunctions engineered to have opposite interface polarities exhibit very similar band offsets and built-in potentials within the LaFeO 3 layer of the same sign. However, heterojunctions with the TiO20-LaO+ interface structure attract electronic charge from the n-STO substrate, whereas those with the SrO0-FeO2-1 interface structure do not. These results suggest that the latter would more effectively facilitate photogenerated electron-hole pair separation than the former, an important result for photoelectrochemical water splitting

Bone graft complications: what can we do to prevent them?

NASA Astrophysics Data System (ADS)

Tandon, Rahul; Herford, Alan S.

2014-03-01

Introduction: Bone grafts are commonly used in oral and maxillofacial surgery, helping to restore missing bone structure and provide osseous support. In spite of their reported success, complications can and do arise. Examples include loosening and resorption of the graft, infection, and complete loss of the graft. These complications can potentially lead to larger defects, necessitating additional procedures to correct the problem. This not only causes great discomfort to the patient, but also drains considerable time and resources away from the clinician. Thus, improvements on identifying ways to identify and prevent these complications are constantly being sought. We have performed a literature review and identified several areas in the field of optics that could potentially help solve our problem. Optical Techniques: Raman spectroscopy has been shown to provide a transcutaneous measurement of bone mineral and matrix Raman bands. This could potentially provide surgeons with the ability to more accurately assess bone graft osseointegration. In-vivo near-infrared optical imaging could potentially provide accurate diagnosis of pathologic lesions such as osteosarcoma. Contrast-enhanced ultrasound could be used to detect vascular disturbances and other information related to the transplantation of osseous components. Conclusion: Bone graft complications can be one of the most devastating consequences of osseous surgery. As surgeons, we are constantly searching for ways to identify them earlier and prevent them. We hope that by presenting areas that could be used, we can gain a better insight to ways in which both fields can benefit.

Effects of electrode size and spacing on sensory modalities in the phantom thumb perception area for the forearm amputees.

PubMed

Li, P; Chai, G H; Zhu, K H; Lan, N; Sui, X H

2015-01-01

Tactile sensory feedback plays a key role in accomplishing the dexterous manipulation of prosthetic hands for the amputees, and the non-invasive transcutaneous electrical nerve stimulation (TENS) of the phantom finger perception (PFP) area would be an effective way to realize sensory feedback clinically. In order to realize the high-spatial-resolution tactile sensory feedback in the PFP region, we investigated the effects of electrode size and spacing on the tactile sensations for potentially optimizing the surface electrode array configuration. Six forearm-amputated subjects were recruited in the psychophysical studies. With the diameter of the circular electrode increasing from 3 mm to 12 mm, the threshold current intensity was enhanced correspondingly under different sensory modalities. The smaller electrode could potentially lead to high sensation spatial resolution. Whereas, the smaller the electrode, the less the number of sensory modalities. For an Φ-3 mm electrode, it is even hard for the subject to perceive any perception modalities under normal stimulating current. In addition, the two-electrode discrimination distance (TEDD) in the phantom thumb perception area decreased with electrode size decreasing in two directions of parallel or perpendicular to the forearm. No significant difference of TEDD existed along the two directions. Studies in this paper would guide the configuration optimization of the TENS electrode array for potential high spatial-resolution sensory feedback.

Orbital operations study. Volume 1: Mission analysis

NASA Technical Reports Server (NTRS)

Steinwachs, W. L.

1972-01-01

The final report of the orbital operations study and a summary of the 25 elements in the study inventory are presented. Fourteen interfacing activities are defined. Eleven mission models encompassing all potential interfacing element pairs and interfacing activities are included.

On Practical Charge Injection at the Metal/Organic Semiconductor Interface

PubMed Central

Kumatani, Akichika; Li, Yun; Darmawan, Peter; Minari, Takeo; Tsukagoshi, Kazuhito

2013-01-01

We have revealed practical charge injection at metal and organic semiconductor interface in organic field effect transistor configurations. We have developed a facile interface structure that consisted of double-layer electrodes in order to investigate the efficiency through contact metal dependence. The metal interlayer with few nanometers thickness between electrode and organic semiconductor drastically reduces the contact resistance at the interface. The improvement has clearly obtained when the interlayer is a metal with lower standard electrode potential of contact metals than large work function of the contact metals. The electrode potential also implies that the most dominant effect on the mechanism at the contact interface is induced by charge transfer. This mechanism represents a step forward towards understanding the fundamental physics of intrinsic charge injection in all organic devices. PMID:23293741

Atomic-Scale Simulation of Electrochemical Processes at Electrode/Water Interfaces under Referenced Bias Potential.

PubMed

Bouzid, Assil; Pasquarello, Alfredo

2018-04-19

Based on constant Fermi-level molecular dynamics and a proper alignment scheme, we perform simulations of the Pt(111)/water interface under variable bias potential referenced to the standard hydrogen electrode (SHE). Our scheme yields a potential of zero charge μ pzc of ∼0.22 eV relative to the SHE and a double layer capacitance C dl of ≃19 μF cm -2 , in excellent agreement with experimental measurements. In addition, we study the structural reorganization of the electrical double layer for bias potentials ranging from -0.92 eV to +0.44 eV and find that O down configurations, which are dominant at potentials above the pzc, reorient to favor H down configurations as the measured potential becomes negative. Our modeling scheme allows one to not only access atomic-scale processes at metal/water interfaces, but also to quantitatively estimate macroscopic electrochemical quantities.

Understanding Protein-Interface Interactions of a Fusion Protein at Silicone Oil-Water Interface Probed by Sum Frequency Generation Vibrational Spectroscopy.

PubMed

Li, Yaoxin; Pan, Duohai; Nashine, Vishal; Deshmukh, Smeet; Vig, Balvinder; Chen, Zhan

2018-02-01

Protein adsorbed at the silicone oil-water interface can undergo a conformational change that has the potential to induce protein aggregation on storage. Characterization of the protein structures at interface is therefore critical for understanding the protein-interface interactions. In this article, we have applied sum frequency generation (SFG) spectroscopy for studying the secondary structures of a fusion protein at interface and the surfactant effect on protein adsorption to silicone oil-water interface. SFG and chiral SFG spectra from adsorbed protein in the amide I region were analyzed. The presence of beta-sheet vibrational band at 1635 cm -1 implies the protein secondary structure was likely perturbed when protein adsorbed at silicone oil interface. The time-dependent SFG study showed a significant reduction in the SFG signal of preadsorbed protein when polysorbate 20 was introduced, suggesting surfactant has stronger interaction with the interface leading to desorption of protein from the interface. In the preadsorbed surfactant and a mixture of protein/polysorbate 20, SFG analysis confirmed that surfactant can dramatically prevent the protein adsorption to silicone oil surface. This study has demonstrated the potential of SFG for providing the detailed molecular level understanding of protein conformation at interface and assessing the influence of surfactant on protein adsorption behavior. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Root-soil air gap and resistance to water flow at the soil-root interface of Robinia pseudoacacia.

PubMed

Liu, X P; Zhang, W J; Wang, X Y; Cai, Y J; Chang, J G

2015-12-01

During periods of water deficit, growing roots may shrink, retaining only partial contact with the soil. In this study, known mathematical models were used to calculate the root-soil air gap and water flow resistance at the soil-root interface, respectively, of Robinia pseudoacacia L. under different water conditions. Using a digital camera, the root-soil air gap of R. pseudoacacia was investigated in a root growth chamber; this root-soil air gap and the model-inferred water flow resistance at the soil-root interface were compared with predictions based on a separate outdoor experiment. The results indicated progressively greater root shrinkage and loss of root-soil contact with decreasing soil water potential. The average widths of the root-soil air gap for R. pseudoacacia in open fields and in the root growth chamber were 0.24 and 0.39 mm, respectively. The resistance to water flow at the soil-root interface in both environments increased with decreasing soil water potential. Stepwise regression analysis demonstrated that soil water potential and soil temperature were the best predictors of variation in the root-soil air gap. A combination of soil water potential, soil temperature, root-air water potential difference and soil-root water potential difference best predicted the resistance to water flow at the soil-root interface. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

FAST TRACK COMMUNICATION Spectral signatures of the surface reconstructions of Au(110)/electrolyte interfaces

NASA Astrophysics Data System (ADS)

Smith, C. I.; Bowfield, A.; Almond, N. J.; Mansley, C. P.; Convery, J. H.; Weightman, P.

2010-10-01

It is demonstrated that the (1 × 1) structure and the (1 × 2) and (1 × 3) surface reconstructions that occur at Au(110)/electrolyte interfaces have unique optical fingerprints. The optical fingerprints are potential, pH and anion dependent and have potential for use in monitoring dynamic changes at this interface. We also observe a specific reflection anisotropy spectroscopy signature that may arise from anions adsorbed on the (1 × 1) structure of Au(110).

Reduction of thermal stresses in continuous fiber reinforced metal matrix composites with interface layers

NASA Technical Reports Server (NTRS)

Jansson, S.; Leckie, F. A.

1990-01-01

The potential of using an interface layer to reduce thermal stresses in the matrix of composites with a mismatch in coefficients of thermal expansion of fiber and matrix was investigated. It was found that compliant layers, with properties of readily available materials, do not have the potential to reduce thermal stresses significantly. However, interface layers with high coefficient of thermal expansion can compensate for the mismatch and reduce thermal stresses in the matrix significantly.

Investigating the roles of touchscreen and physical control interface characteristics on driver distraction and multitasking performance.

DOT National Transportation Integrated Search

2016-01-01

This study aimed to assess the potential of driver distraction, task performance, orientation of : attention, and perceived workload in a multitasking situation involving interaction with touchscreen : interface, compared to physical interface. Autho...

The Effectiveness of Acupuncture for Chronic Daily Headache: An Outcomes Study

DTIC Science & Technology

2009-12-01

1107 -t- 3 chan- nel transcutaneous electrical nerve stimulator ( TENS ) units. The negative or black lead was clipped onto the needle in.serted at...arc easily accessible for electrical tonification, especially for acupuncture naive subjects. They can also be used during an acute headache episode...ache, warmth, tingling, pressure, or radiation). Mild electrical tonification was applied to the 2 acu- puncture needles in tbe foot, using an ITO-IC

The Effects of Electroacupuncture on Cyclophosphamide-Induced Emesis in Ferrets.

DTIC Science & Technology

1996-07-01

Other studies conducted by Dundee’s group showed that acupressure and transcutaneous electrical stimulation ( TENS ) of the same acupoints also benefited...typically left in place for 20-30 minutes. The effects of acupuncture may be augmented with electrical stimulation (EA) and/or heat (e.g. moxibustion). Side...electrodes (Grass) were attached to the end of the needles and electrical stimulation was applied (the EA parameters will be described in detail later

Optogenetic Stimulation of Peripheral Vagus Nerves using Flexible OLED Display Technology to Treat Chronic Inflammatory Disease and Mental Health Disorders

DTIC Science & Technology

2016-03-31

transcutaneously via the outer ear using a high-resolution, addressable array of organic light emitting diodes (OLEDs) manufactured on a flexible...therapeutic optical stimulation in optogenetically modified neural tissue. Keywords: Optogenetics; neuromodulation; organic light emitting diode ...the outer ear using a high-resolution, two-dimensional (2-D), addressable array of red organic light - emitting diodes (OLEDs) manufactured on a thin

Atomistic and Coarse-Grained Modeling of the Adsorption of Graphene Nanoflakes at the Oil-Water Interface.

PubMed

Ardham, Vikram Reddy; Leroy, Frédéric

2018-03-01

The high interfacial tension between two immiscible liquids can provide the necessary driving force for the self-assembly of nanoparticles at the interface. Particularly, the interface between water and oily liquids (hydrocarbon chains) has been exploited to prepare networks of highly interconnected graphene sheets of only a few layers thickness, which are well suited for industrial applications. Studying such complex systems through particle-based simulations could greatly enhance the understanding of the various driving forces in action and could possibly give more control over the self-assembly process. However, the interaction potentials used in particle-based simulations are typically derived by reproducing bulk properties and are therefore not suitable for describing systems dominated by interfaces. To address this issue, we introduce a methodology to derive solid-liquid interaction potentials that yield an accurate representation of the balance between interfacial interactions at atomistic and coarse-grained resolutions. Our approach is validated through its ability to lead to the adsorption of graphene nanoflakes at the interface between water and n-hexane. The development of accurate coarse-grained potentials that our approach enables will allow us to perform large-scale simulations to study the assembly of graphene nanoparticles at the interface between immiscible liquids. Our methodology is illustrated through a simulation of many graphene nanoflakes adsorbing at the interface.

Assessing land clearing potential in the Canadian agriculture–forestry interface with a multi-attribute frontier approach

Treesearch

Denys Yemshanov; Frank Koch; Kurt H. Riitters; Brian McConkey; Ted Huffmand; Stephen Smithe

2015-01-01

The pattern of forest land clearing in a region can be viewed as a gauge of sustainable (or unsustain-able) use of agricultural and forest resources. In this study we examine the geographical distribution ofland clearing potential in the Canadian agriculture–forestry interface and propose a new landscape-scaleindicator that quantifies this potential. We consider the...

The electrostatics of solvent and membrane interfaces and the role of electronic polarizability

NASA Astrophysics Data System (ADS)

Vorobyov, Igor; Allen, Toby W.

2010-05-01

The electrostatics of solvent and lipid bilayer interfaces are investigated with the aim of understanding the interaction of ions and charged peptides with biological membranes. We overcome the lacking dielectric response of hydrocarbon by carrying out atomistic molecular dynamics simulations using a polarizable model. For air-solvent or solvent-solvent interfaces, the effect of polarizability itself is small, yet changes in the fixed atomic charge distribution are responsible for substantial changes in the potential. However, when electrostatics is probed by finite solutes, a cancellation of dominant quadrupolar terms from the macroscopic and microscopic (solute-solvent) interfaces eliminates this dependence and leads to small net contributions to partitioning thermodynamics. In contrast, the membrane dipole potential exhibits considerable dependence on lipid electronic polarizability, due to its dominant dipolar contribution. We report the dipole potential for a polarizable lipid hydrocarbon membrane model of 480-610 mV, in better accord with experimental measurements.

Axial interface optical phonon modes in a double-nanoshell system.

PubMed

Kanyinda-Malu, C; Clares, F J; de la Cruz, R M

2008-07-16

Within the framework of the dielectric continuum (DC) model, we analyze the axial interface optical phonon modes in a double system of nanoshells. This system is constituted by two identical equidistant nanoshells which are embedded in an insulating medium. To illustrate our results, typical II-VI semiconductors are used as constitutive polar materials of the nanoshells. Resolution of Laplace's equation in bispherical coordinates for the potentials derived from the interface vibration modes is made. By imposing the usual electrostatic boundary conditions at the surfaces of the two-nanoshell system, recursion relations for the coefficients appearing in the potentials are obtained, which entails infinite matrices. The problem of deriving the interface frequencies is reduced to the eigenvalue problem on infinite matrices. A truncating method for these matrices is used to obtain the interface phonon branches. Dependences of the interface frequencies on the ratio of inter-nanoshell separation to core size are obtained for different systems with several values of nanoshell interdistance. Effects due to the change of shell and embedding materials are also investigated in interface phonon modes.

Misfit strain driven cation inter-diffusion across an epitaxial multiferroic thin film interface

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

Sankara Rama Krishnan, P. S.; Munroe, Paul; Nagarajan, V.

Cation intermixing at functional oxide interfaces remains a highly controversial area directly relevant to interface-driven nanoelectronic device properties. Here, we systematically explore the cation intermixing in epitaxial (001) oriented multiferroic bismuth ferrite (BFO) grown on a (001) lanthanum aluminate (LAO) substrate. Aberration corrected dedicated scanning transmission electron microscopy and electron energy loss spectroscopy reveal that the interface is not chemically sharp, but with an intermixing of ∼2 nm. The driving force for this process is identified as misfit-driven elastic strain. Landau-Ginzburg-Devonshire-based phenomenological theory was combined with the Sheldon and Shenoy formula in order to understand the influence of boundary conditions andmore » depolarizing fields arising from misfit strain between the LAO substrate and BFO film. The theory predicts the presence of a strong potential gradient at the interface, which decays on moving into the bulk of the film. This potential gradient is significant enough to drive the cation migration across the interface, thereby mitigating the misfit strain. Our results offer new insights on how chemical roughening at oxide interfaces can be effective in stabilizing the structural integrity of the interface without the need for misfit dislocations. These findings offer a general formalism for understanding cation intermixing at highly strained oxide interfaces that are used in nanoelectronic devices.« less

Interfacial Energy Alignment at the ITO/Ultra-Thin Electron Selective Dielectric Layer Interface and Its Effect on the Efficiency of Bulk-Heterojunction Organic Solar Cells.

PubMed

Itoh, Eiji; Goto, Yoshinori; Saka, Yusuke; Fukuda, Katsutoshi

2016-04-01

We have investigated the photovoltaic properties of an inverted bulk heterojunction (BHJ) cell in a device with an indium-tin-oxide (ITO)/electron selective layer (ESL)/P3HT:PCBM active layer/MoOx/Ag multilayered structure. The insertion of only single layer of poly(diallyl-dimethyl-ammonium chloride) (PDDA) cationic polymer film (or poly(ethyleneimine) (PEI) polymeric interfacial dipole layer) and titanium oxide nanosheet (TN) films as an ESL effectively improved cell performance. Abnormal S-shaped curves were observed in the inverted BHJ cells owing to the contact resistance across the ITO/active layer interface and the ITO/PDDA/TN/active layer interface. The series resistance across the ITO/ESL interface in the inverted BHJ cell was successfully reduced using an interfacial layer with a positively charged surface potential with respect to ITO base electrode. The positive dipole in PEI and the electronic charge phenomena at the electrophoretic deposited TN (ED-TN) films on ITO contributed to the reduction of the contact resistance at the electrode interface. The surface potential measurement revealed that the energy alignment by the transfer of electronic charges from the ED-TN to the base electrodes. The insertion of the ESL with a large positive surface potential reduced the potential barrier for the electron injection at ITO/TN interface and it improved the photovoltaic properties of the inverted cell with an ITO/TN/active layer/MoOx/Ag structure.

Zeta potential in oil-water-carbonate systems and its impact on oil recovery during controlled salinity water-flooding

PubMed Central

Jackson, Matthew D.; Al-Mahrouqi, Dawoud; Vinogradov, Jan

2016-01-01

Laboratory experiments and field trials have shown that oil recovery from carbonate reservoirs can be increased by modifying the brine composition injected during recovery in a process termed controlled salinity water-flooding (CSW). However, CSW remains poorly understood and there is no method to predict the optimum CSW composition. This work demonstrates for the first time that improved oil recovery (IOR) during CSW is strongly correlated to changes in zeta potential at both the mineral-water and oil-water interfaces. We report experiments in which IOR during CSW occurs only when the change in brine composition induces a repulsive electrostatic force between the oil-brine and mineral-brine interfaces. The polarity of the zeta potential at both interfaces must be determined when designing the optimum CSW composition. A new experimental method is presented that allows this. Results also show for the first time that the zeta potential at the oil-water interface may be positive at conditions relevant to carbonate reservoirs. A key challenge for any model of CSW is to explain why IOR is not always observed. Here we suggest that failures using the conventional (dilution) approach to CSW may have been caused by a positively charged oil-water interface that had not been identified. PMID:27876833

The Graphical User Interface: Crisis, Danger, and Opportunity.

ERIC Educational Resources Information Center

Boyd, L. H.; And Others

1990-01-01

This article describes differences between the graphical user interface and traditional character-based interface systems, identifies potential problems posed by graphic computing environments for blind computer users, and describes some programs and strategies that are being developed to provide access to those environments. (Author/JDD)

Water Density in the Electric Double Layer at the Insulator/Electrolyte Solution Interface

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

Tikhonov,A.

I studied the spatial structure of the thick transition region between n-hexane and a colloidal solution of 7-nm silica particles by X-ray reflectivity and grazing incidence small-angle scattering. The interfacial structure is discussed in terms of a semiquantitative interface model wherein the potential gradient at the n-hexane/sol interface reflects the difference in the potentials of 'image forces' between the cationic Na{sup +} and anions (nanoparticles) and the specific adsorption of surface charge at the interface between the adsorbed layer and the solution, as well as at the interface between the adsorbed layer and n-hexane. The X-ray scattering data revealed thatmore » the average density of water in the field {approx}10{sup 9}-10{sup 10} V/m of the electrical double layer at the hexane/silica sol interface is the same as, or only few percent higher (1-7%) than, its density under normal conditions.« less

Wedge disclination dipole in an embedded nanowire within the surface/interface elasticity

NASA Astrophysics Data System (ADS)

Shodja, Hossein M.; Rezazadeh-Kalehbasti, Shaghayegh; Gutkin, Mikhail Yu

2013-12-01

The elastic behavior of an arbitrary oriented wedge disclination dipole located inside a nanowire, which in turn is embedded in an infinite matrix, is studied within the surface/interface theory of elasticity. The corresponding boundary value problem is provided using complex potential functions. The potential functions are defined through modeling the wedge disclination in terms of an equivalent distribution of edge dislocations. The interface effects on the stress field and strain energy of the disclination dipole and image forces acting on it, the influence of relative shear moduli of the nanowire and the matrix, as well as the different characteristics of the interface are studied thoroughly. It is shown that the positive interface modulus leads to increased strain energy and extra repulsive forces on the disclination dipole. The noticeable effect of the negative interface modulus is the non-classical oscillations in the stress field of the disclination dipole and an extra attractive image force on it.

The Application of Transcutaneous CO2 Pressure Monitoring in the Anesthesia of Obese Patients Undergoing Laparoscopic Bariatric Surgery

PubMed Central

Liu, Shijiang; Sun, Jie; Chen, Xing; Yu, Yingying; Liu, Xuan; Liu, Cunming

2014-01-01

To investigate the correlation and accuracy of transcutaneous carbon dioxide partial pressure (PTCCO2) with regard to arterial carbon dioxide partial pressure (PaCO2) in severe obese patients undergoing laparoscopic bariatric surgery. Twenty-one patients with BMI>35 kg/m2 were enrolled in our study. Their PaCO2, end-tidal carbon dioxide partial pressure (PetCO2), as well as PTCCO2 values were measured at before pneumoperitoneum and 30 min, 60 min, 120 min after pneumoperitoneum respectively. Then the differences between each pair of values (PetCO2–PaCO2) and. (PTCCO2–PaCO2) were calculated. Bland–Altman method, correlation and regression analysis, as well as exact probability method and two way contingency table were employed for the data analysis. 21 adults (aged 19–54 yr, mean 29, SD 9 yr; weight 86–160 kg, mean119.3, SD 22.1 kg; BMI 35.3–51.1 kg/m2, mean 42.1,SD 5.4 kg/m2) were finally included in this study. One patient was eliminated due to the use of vaso-excitor material phenylephrine during anesthesia induction. Eighty-four sample sets were obtained. The average PaCO2–PTCCO2 difference was 0.9±1.3 mmHg (mean±SD). And the average PaCO2–PetCO2 difference was 10.3±2.3 mmHg (mean±SD). The linear regression equation of PaCO2–PetCO2 is PetCO2 = 11.58+0.57×PaCO2 (r2 = 0.64, P<0.01), whereas the one of PaCO2–PTCCO2 is PTCCO2 = 0.60+0.97×PaCO2 (r2 = 0.89). The LOA (limits of agreement) of 95% average PaCO2–PetCO2 difference is 10.3±4.6 mmHg (mean±1.96 SD), while the LOA of 95% average PaCO2–PTCCO2 difference is 0.9±2.6 mmHg (mean±1.96 SD). In conclusion, transcutaneous carbon dioxide monitoring provides a better estimate of PaCO2 than PetCO2 in severe obese patients undergoing laparoscopic bariatric surgery. PMID:24699267

Transcutaneous Electrical Nerve Stimulation for Treating Neurogenic Lower Urinary Tract Dysfunction: A Systematic Review.

PubMed

Gross, Tobias; Schneider, Marc P; Bachmann, Lucas M; Blok, Bertil F M; Groen, Jan; Hoen, Lisette A 't; Castro-Diaz, David; Padilla Fernández, Bárbara; Del Popolo, Giulio; Musco, Stefania; Hamid, Rizwan; Ecclestone, Hazel; Karsenty, Gilles; Phé, Véronique; Pannek, Jürgen; Kessler, Thomas M

2016-06-01

Transcutaneous electrical nerve stimulation (TENS) is a promising therapy for non-neurogenic lower urinary tract dysfunction and might also be a valuable option in patients with an underlying neurological disorder. We systematically reviewed all available evidence on the efficacy and safety of TENS for treating neurogenic lower urinary tract dysfunction. The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. After screening 1943 articles, 22 studies (two randomised controlled trials, 14 prospective cohort studies, five retrospective case series, and one case report) enrolling 450 patients were included. Eleven studies reported on acute TENS and 11 on chronic TENS. In acute TENS and chronic TENS, the mean increase of maximum cystometric capacity ranged from 69ml to 163ml and from 4ml to 156ml, the mean change of bladder volume at first detrusor overactivity from a decrease of 13ml to an increase of 175ml and from an increase of 10ml to 120ml, a mean decrease of maximum detrusor pressure at first detrusor overactivity from 18 cmH20 to 72 cmH20 and 8 cmH20, and a mean decrease of maximum storage detrusor pressure from 20 cmH20 to 58 cmH2O and from 3 cmH20 to 8 cmH2O, respectively. In chronic TENS, a mean decrease in the number of voids and leakages per 24h ranged from 1 to 3 and from 0 to 4, a mean increase of maximum flow rate from 2ml/s to 7ml/s, and a mean change of postvoid residual from an increase of 26ml to a decrease of 85ml. No TENS-related serious adverse events have been reported. Risk of bias and confounding was high in most studies. Although preliminary data suggest TENS might be effective and safe for treating neurogenic lower urinary tract dysfunction, the evidence base is poor and more reliable data from well-designed randomised controlled trials are needed to make definitive conclusions. Early data suggest that transcutaneous electrical nerve stimulation might be effective and safe for treating neurogenic lower urinary tract dysfunction, but more reliable evidence is required. Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Verification of an optimized stimulation point on the abdominal wall for transcutaneous neuromuscular electrical stimulation for activation of deep lumbar stabilizing muscles.

PubMed

Baek, Seung Ok; Cho, Hee Kyung; Jung, Gil Su; Son, Su Min; Cho, Yun Woo; Ahn, Sang Ho

2014-09-01

Transcutaneous neuromuscular electrical stimulation (NMES) can stimulate contractions in deep lumbar stabilizing muscles. An optimal protocol has not been devised for the activation of these muscles by NMES, and information is lacking regarding an optimal stimulation point on the abdominal wall. The goal was to determine a single optimized stimulation point on the abdominal wall for transcutaneous NMES for the activation of deep lumbar stabilizing muscles. Ultrasound images of the spinal stabilizing muscles were captured during NMES at three sites on the lateral abdominal wall. After an optimal location for the placement of the electrodes was determined, changes in the thickness of the lumbar multifidus (LM) were measured during NMES. Three stimulation points were investigated using 20 healthy physically active male volunteers. A reference point R, 1 cm superior to the iliac crest along the midaxillary line, was used. Three study points were used: stimulation point S1 was located 2 cm superior and 2 cm medial to the anterior superior iliac spine, stimulation point S3 was 2 cm below the lowest rib along the same sagittal plane as S1, and stimulation point S2 was midway between S1 and S3. Sessions were conducted stimulating at S1, S2, or S3 using R for reference. Real-time ultrasound imaging (RUSI) of the abdominal muscles was captured during each stimulation session. In addition, RUSI images were captured of the LM during stimulation at S1. Thickness, as measured by RUSI, of the transverse abdominis (TrA), obliquus internus, and obliquus externus was greater during NMES than at rest for all three study points (p<.05). Transverse abdominis was significantly stimulated more by NMES at S1 than at the other points (p<.05). The LM thickness was also significantly greater during NMES at S1 than at rest (p<.05). Neuromuscular electrical stimulation at S1 optimally activated deep spinal stabilizing muscles, TrA and LM, as evidenced by RUSI. The authors recommend this optimal stimulation point be used for NMES in the course of lumbar spine stabilization training in patients having difficulty initiating contraction of these muscles. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of a self-administered transcutaneous electrical stimulation concept for the treatment of spasticity: a randomised placebo-controlled trial.

PubMed

Ertzgaard, Per; Alwin, Jenny; Sörbo, Ann; Lindgren, Marie; Sandsjö, Leif

2017-10-25

Spasticity is a common consequence of injury to the central nervous system negatively affecting patient's everyday activities. Treatment mainly consists of training and different drugs, often with side effects. There is a need for treatment options that can be performed by the patient in their home environment. The objective of this study was to assess the effectiveness of an assistive technology (AT), Mollii®, a garment with integrated electrodes for multifocal transcutaneous electrical stimulation intended for self-treatment of spasticity, in study participants with spasticity due to stroke or CP. The study was a randomised, controlled, double-blind study with a cross-over design. Participants were recruited from two rehabilitation clinics. Treatments were performed in participants' homes and all follow-ups were performed in the two rehabilitation clinics. Thirty-one participants were included in the study and 27 completed the study. Four participants discontinued the study. Two declined participation before baseline and two withdrew due to problems handling the garment. Participants used the AT with and without electrical stimulation (active/non-active period) for six weeks each, followed by six weeks without treatment. Goal Attainment Scaling (GAS), change in mobility, arm-hand ability, spasticity and pain were measured at baseline and after six, 12 and 18 weeks. Fifteen of the 27 participants fulfilled the treatment protocol in terms of recommended use. Deviations were frequent. No statistically significant differences in outcome were found between the active and the non-active treatment periods. During the active period, an improvement was seen in the 10-metre comfortable gait test, time and steps. An improvement was seen in both the active and non-active periods for the GAS. Compliance was low, partly due to deviations related to the garment, complicating the interpretation of the results. Further research should focus on identifying the target population and concomitant rehabilitation strategies. The evaluated concept of multifocal transcutaneous electrical stimulation (TES) represents an interesting addition to the existing repertoire of treatments to alleviate muscle spasticity. The evaluated concept allows TES to be self-administered by the patient in the home environment. A more elaborate design of training activities directly related to patient´s own rehabilitation goals is recommended and may increase the value of the evaluated concept.

Effects of acupuncture and transcutaneous stimulation analgesia on plasma hormone levels during and after major abdominal surgery.

PubMed

Kho, H G; Kloppenborg, P W; van Egmond, J

1993-05-01

The effects of acupuncture and transcutaneous electrical stimulation (TES) on plasma adrenaline (A) and noradrenaline (NA), adrenocorticotropic hormone (ACTH), beta-endorphin (beta E), anti-diuretic hormone (ADH) and hydrocortisone (cortisol) were evaluated during and, for four days after surgery in 42 male patients submitted to a standardized major abdominal operation in a comparative study of three different anaesthetic techniques. Group 1 received acupuncture and transcutaneous stimulation as the main non-pharmacological analgesic during surgery. Group 2 received moderate-dose fentanyl (initial bolus of 10 micrograms kg-1 followed by continuous infusion of 5 micrograms kg-1 h-1 for the first hour, and then 4 micrograms kg-1 h-1. Group 3 received a combination of both methods. In all three groups analgesia was supplemented, if necessary, by small bolus injections of 50 micrograms fentanyl. Anaesthesia was induced in all groups with thiopentone 5 mg kg-1 and vecuronium 0.1 mg kg-1 and patients were ventilated (N2O:O2 = 2:1) to achieve normocapnia without the use of a halogenated agent. Pre-operatively acupuncture plus TES in Groups 1 and 3 led to a rise in beta E (P < 0.05) without changes of haemodynamics. After intubation beta E did not increase further. Intubation in Group 2 led to an increase of beta E (P < 0.05) also, and to a rise in pulse rate and blood pressure (P < 0.05) in all three groups. Per-operatively acupuncture plus TES in Group 1 showed a response of circulating NA and cortisol similar to that in Groups 2 and 3, whereas the responses of the circulating A, ACTH, beta E and ADH in Group 1 were more pronounced (P < 0.01). Post-operatively no differences in the hormonal profiles could be discerned between the groups with or without acupuncture plus TES (Group 2 vs. Group 3) nor between those with or without moderate-dose fentanyl anaesthesia (Group 1 vs. Group 3). It is concluded that acupuncture and TES have no effect on the cardiovascular response to laryngoscopy and intubation. They can replace moderate-dose fentanyl anaesthesia in major abdominal surgery at the cost of a more enhanced per-operative neuroendocrine stress response, which does not, however, influence the postoperative hormonal profiles nor the rapidity of return to pre-operative values.

Transcutaneous laser treatment of leg veins.

PubMed

Meesters, Arne A; Pitassi, Luiza H U; Campos, Valeria; Wolkerstorfer, Albert; Dierickx, Christine C

2014-03-01

Leg telangiectasias and reticular veins are a common complaint affecting more than 80% of the population to some extent. To date, the gold standard remains sclerotherapy for most patients. However, there may be some specific situations, where sclerotherapy is contraindicated such as needle phobia, allergy to certain sclerosing agents, and the presence of vessels smaller than the diameter of a 30-gauge needle (including telangiectatic matting). In these cases, transcutaneous laser therapy is a valuable alternative. Currently, different laser modalities have been proposed for the management of leg veins. The aim of this article is to present an overview of the basic principles of transcutaneous laser therapy of leg veins and to review the existing literature on this subject, including the most recent developments. The 532-nm potassium titanyl phosphate (KTP) laser, the 585-600-nm pulsed dye laser, the 755-nm alexandrite laser, various 800-983-nm diode lasers, and the 1,064-nm neodymium yttrium-aluminum-garnet (Nd:YAG) laser and various intense pulsed light sources have been investigated for this indication. The KTP and pulsed dye laser are an effective treatment option for small vessels (<1 mm). The side effect profile is usually favorable to that of longer wavelength modalities. For larger veins, the use of a longer wavelength is required. According to the scarce evidence available, the Nd:YAG laser produces better clinical results than the alexandrite and diode laser. Penetration depth is high, whereas absorption by melanin is low, making the Nd:YAG laser suitable for the treatment of larger and deeply located veins and for the treatment of patients with dark skin types. Clinical outcome of Nd:YAG laser therapy approximates that of sclerotherapy, although the latter is associated with less pain. New developments include (1) the use of a nonuniform pulse sequence or a dual-wavelength modality, inducing methemoglobin formation and enhancing the optical absorption properties of the target structure, (2) pulse stacking and multiple pass laser treatment, (3) combination of laser therapy with sclerotherapy or radiofrequency, and (4) indocyanin green enhanced laser therapy. Future studies will have to confirm the role of these developments in the treatment of leg veins. The literature still lacks double-blind controlled clinical trials comparing the different laser modalities with each other and with sclerotherapy. Such trials should be the focus of future research.

A tiered approach to the use of alternatives to animal testing for the safety assessment of cosmetics: skin irritation.

PubMed

Macfarlane, Martin; Jones, Penny; Goebel, Carsten; Dufour, Eric; Rowland, Joanna; Araki, Daisuke; Costabel-Farkas, Margit; Hewitt, Nicola J; Hibatallah, Jalila; Kirst, Annette; McNamee, Pauline; Schellauf, Florian; Scheel, Julia

2009-07-01

Evaluation of the skin irritancy and corrosivity potential of an ingredient is a necessity in the safety assessment of cosmetic ingredients. To date, there are two formally validated alternatives to the rabbit Draize test for skin corrosivity in place, namely the rat skin transcutaneous electrical resistance (TER) assay and the Human Skin Model Test using EpiSkin, EpiDerm and SkinEthic reconstructed human epidermal equivalents. For skin irritation, EpiSkin, EpiDerm and SkinEthic are validated as stand-alone test replacements for the rabbit Draize test. Data from these tests are rarely considered in isolation and are evaluated in combination with other factors to establish the overall irritating or corrosive potential of an ingredient. In light of the deadlines established in the Cosmetics Directive for cessation of animal testing for cosmetic ingredients, a COLIPA scientific meeting was held in Brussels on 30th January, 2008 to review the use of alternative approaches and to set up a decision tree approach for their integration into tiered testing strategies for hazard and safety assessment of cosmetic ingredients and their use in products. In conclusion, the safety assessments for skin irritation/corrosion of new chemicals for use in cosmetics can be confidently accomplished using exclusively alternative methods.

Spatially offset raman spectroscopy for non-invasive assessment of fracture healing

NASA Astrophysics Data System (ADS)

Ding, Hao; Lu, Guijin; West, Christopher; Gogola, Gloria; Kellam, James; Ambrose, Catherine; Bi, Xiaohong

2016-02-01

Fracture non-unions and bone re-fracture are common challenges for post-fracture management. To achieve better prognosis and treatment evaluation, it is important to be able to assess the quality of callus over the time course of healing. This study evaluated the potential of spatially offset Raman spectroscopy for assessing the fracture healing process in situ. We investigated a rat model of fracture healing at two weeks and 4 weeks post fracture with a fractured femur and a contralateral control in each animal. Raman spectra were collected from the depilated thighs on both sides transcutaneously in situ with various source/detection offsets. Bone signals were recovered from SORS spectra, and then compared with those collected from bare bones. The relative intensity of mineral from fractured bone was markedly decreased compared to the control. The fractured bones demonstrated lower mineral and carbonate level and higher collagen content in the callus at the early time point. Compared to week 2, collagen mineralization and mineral carbonation increased at 4 weeks post fracture. Similarly, the material properties of callus determined by reference point indentation also increased in the 4-week group, indicating improved callus quality with time. The results from Raman analysis are in agreement with radiographic and material testing, indicating the potential of this technique in assessing fracture healing in vivo.

Interface potential sensing from adsorption of human serum albumin (HSA) on carbon nanotube (CNT) monitored by zero current potentiometry for HSA determination.

PubMed

Wang, Huan; Wu, Yi; Song, Jun-Feng

2015-10-15

In this work, the adsorption of human serum albumin (HSA) on the bare multiwall carbon nanotube (MWNT) was investigated by a new electrochemical method, termed as zero current potentiometry. For this, a MWNT strip was prepared by directly adhering MWNTs on the transparent adhesive tape surface. Moreover, when HSA adsorbed onto MWNT at the MWNT/solution interface, an interface potential Ψ yielded. The interface potential Ψ as the zero current potential Ezcp simply related to it was monitored by zero current potentiometry. The relationship between the zero current potential Ezcp, the HSA concentration and others was established in simple stoichiometric relation. Based on this, both the adsorption of HSA on MWNT and the HSA determination can be studied. For the HSA determination, the theoretic conclusion consisted with experimental results. The zero current potential Ezcp was proportional to the HSA concentration in the range of 2.8 × 10(-8) - 3.4 × 10(-7)M with the limit of detection 2 × 10(-8)M. The linear regression equation was Ezcp/V (vs, SCE) = (0.159 ± 0.01) + (0.358 ± 0.02) × 10(6)CHSA (µM). This determination was fast, high sensitive and good selective. Copyright © 2015 Elsevier B.V. All rights reserved.

A Prototype Graphical User Interface for Co-op: A Group Decision Support System.

DTIC Science & Technology

1992-03-01

achieve their potential to communicate. Information-oriented, systematic graphic design is the use of typography , symbols, color, and other static and...apphcuittin by reducig Uber ellurt anid enhuncizig Iliteracti. ’Iliis thesis designs and de% elupht Itrututylle Graphical User Interface iGUl i fui Cu f...ORGANIZATION.... .. .. ............ II. INTERFACE DESIGN PRINCIPLES. .............. 7 A. GRAPHICAL USER INTERFACES.............7 1. Design Principles

Surface currents on the plasma-vacuum interface in MHD equilibria

NASA Astrophysics Data System (ADS)

Hanson, James

2017-10-01

The VMEC non-axisymmetric MHD equilibrium code can compute free-boundary equilibria. Since VMEC assumes that magnetic fields within the plasma form closed and nested flux surfaces, the plasma-vacuum interface is a flux surface, and the total magnetic field there has no normal component. VMEC imposes this condition of zero normal field using the potential formulation of Merkel, and solves a Neumann problem for the magnetic potential in the exterior region. This boundary condition necessarily admits the possibility of a surface current on the interface. While this surface current may be small in MHD equilibrium, it is readily computed in terms of the magnetic potentials in both the interior and exterior regions, evaluated on the surface. If only the external magnetic potential is known (as in VMEC), then the surface current can be computed from the discontinuity of the tangential field across the interface. Examples of the surface current for VMEC equilibria will be shown for a zero-pressure stellarator equilibrium. Field-line following of the vacuum magnetic field shows magnetic islands within the plasma region.

Cardiac Ischemia Model for +Gz Using Miniature Swine and Baboons

DTIC Science & Technology

2008-04-01

VAP was tunneled subcutaneously to an incision in the ventral neck and placed in the superior vena cava just craniad to the right atrium through...was passed transcutaneously to the su- perior vena cava from the arm or to the inferior vena cava from the lower leg, using fl uoroscopy. The...Five control swine were maintained on a standard swine diet. Also, nine male baboons had a constrictor placed around the left anterior descending

A prospective study analyzing the application of radiofrequency energy and high-voltage, ultrashort pulse duration electrical fields on the quantitative reduction of adipose tissue

PubMed Central

Duncan, Diane Irvine; Kim, Theresa H. M.; Temaat, Robbin

2016-01-01

Noninvasive fat reduction is claimed by many device manufacturers, but proof of efficacy has been difficult to establish. This prospective study was designed to measure the reduction of fat thickness and actual volume reduction in 20 female patients treated with an external radiofrequency (RF) device. This device combines RF heat, suction coupled vacuum, and oscillating electrical pulses that induce adipocyte death over time. Patients underwent pre- and post-treatment and intercurrent measurements of weight, body mass index, ultrasonic transcutaneous fat thickness, and 2D and 3D Vectra photography with independent calculation of circumferential and volumetric change. Mean transcutaneous ultrasound thickness at reproducible points was 2.78 cm; at 1-month post-treatment, the mean fat thickness was 1.71 cm. At 3-month post-treatment, the mean fat thickness reduction was 39.6%. Vectra circumference measurements were taken at 10-mm intervals, with postural and breathing cycle control. Independent analysis of serial measurements from + 60 to − 70 mm showed mean abdominal circumference measurement of 2.3 cm. Mean abdominal volume loss was 202.4 and 428.5 cc at 1- and 3-month post-treatment, respectively. Scanning electron microscopy confirmed that permanent cell destruction was caused by irreversible electroporation. Pyroptosis appears to be the mechanism of action. PMID:26962636

Transcutaneous Electrical Nerve Stimulation Reduces Post-Thoractomy Ipsilateral Shoulder Pain. A Prospective Randomized Study.

PubMed

Esteban González, Pedro; Novoa, Nuria M; Varela, Gonzalo

2015-12-01

The patient's position during an axillary thoracotomy can cause postoperative pain and decrease mobility of the ipsilateral shoulder. In this study, we assessed whether the implementation of a standardized analgesia program using transcutaneous electrical nerve stimulation (TENS) decreases local pain and improves ipsilateral shoulder mobility. Randomized, single-blind, single-center clinical trial of 50 patients who had undergone anatomical lung resection via axillary muscle-sparing thoracotomy. Patients were treated with TENS devices for 30 minutes every 8 hours, beginning on postoperative day 1. Pain and mobility of the affected limb were recorded at the same time on postoperative days 1 through 3. A visual analogue scale was used for pain assessment and shoulder mobility was assessed with a goniometer. Results were compared using a non-parametric test. Twenty-five patients were randomized to each group. Mean age of the control group was 62.7±9.3 years and 63.4±10.2 years in the experimental group. Shoulder mobility parameters were similar in both groups on all postoperative days. However, pain during flexion significantly decreased on day 2 (P=.03) and day 3 (P=.04) in the experimental group. The use of TENS decreases pain from shoulder flexion in patients undergoing axillary thoracotomy for pulmonary resection. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

Transcutaneous electrical nerve stimulation (TENS) for pain control after vaginal delivery and cesarean section.

PubMed

Kayman-Kose, Seda; Arioz, Dagistan Tolga; Toktas, Hasan; Koken, Gulengul; Kanat-Pektas, Mine; Kose, Mesut; Yilmazer, Mehmet

2014-10-01

The present study aims to determine the efficiency and reliability of transcutaneous electrical nerve stimulation (TENS) in the management of pain related with uterine contractions after vaginal delivery and the pain related with both abdominal incision uterine contractions after cesarean section. A hundred healthy women who underwent cesarean section under general anesthesia were randomly assigned to the placebo group (Group 1) or the TENS group (Group 2), while 100 women who delivered by vaginal route without episiotomy were randomized into the placebo group (Group 3) or the TENS group (Group 4). The patients in Group 2 had statistically lower visual analog scale (VAS) and verbal numerical scale (VNS) scores than the patients in Group 1 (p < 0.001 for both). The patients in Group 4 had statistically lower VAS and VNS scores than the patients in Group 3 (p = 0.022 and p = 0.005, respectively). The analgesic requirement at the eighth hour of cesarean section was significantly lower in the patients who were treated with TENS (p = 0.006). The need for analgesics at the eighth hour of vaginal delivery was statistically similar in the patients who were treated with TENS and the patients who received placebo (p = 0.830). TENS is an effective, reliable, practical and easily available modality of treatment for postpartum pain.

Increased Release of Serotonin in the Spinal Cord During Low, But Not High, Frequency Transcutaneous Electric Nerve Stimulation in Rats With Joint Inflammation

PubMed Central

Sluka, Kathleen A.; Lisi, Tammy L.; Westlund, Karin N.

2009-01-01

Objective To determine the release pattern of serotonin and noradrenaline in the spinal cord in response to transcutaneous electric nerve stimulation (TENS) delivered at low or high frequency. Design Prospective randomized allocation of 3 treatments. Setting Research laboratory. Animals Male Sprague-Dawley rats (weight range, 250–350g). Intervention Knee joints of rats were inflamed with a mixture of 3% carrageenan and 3% kaolin for 24 hours prior to placement of push-pull cannulae into the dorsal horn of the spinal cord. Push-pull samples were collected in 10-minute intervals before, during, and after treatment with low-frequency TENS (4Hz), high-frequency TENS (100Hz), or sham TENS. TENS was applied to the inflamed knee joint for 20 minutes at sensory intensity and 100-μs pulse duration. Push-pull samples were analyzed for serotonin and noradrenaline by high performance liquid chromatography with coulemetric detection. Main Outcome Measures Spinal concentrations of serotonin and noradrenaline. Results Low-frequency TENS significantly increased serotonin concentrations during and immediately after treatment. There was no change in serotonin with high-frequency TENS, nor was there a change in noradrenaline with low- or high-frequency TENS. Conclusions Low-frequency TENS releases serotonin in the spinal cord to produce antihyperalgesia by activation of serotonin receptors. PMID:16876561

An investigation into the perceptual embodiment of an artificial hand using transcutaneous electrical nerve stimulation (TENS) in intact-limbed individuals.

PubMed

Mulvey, Matthew; Fawkner, Helen; Johnson, Mark I

2014-01-01

Perceptual embodiment of an artificial limb aids manual control of prostheses and can be facilitated by somatosensory feedback. We hypothesised that transcutaneous electrical nerve stimulation (TENS) may facilitate perceptual embodiment of artificial limbs. To determine the effect of TENS on perceptual embodiment of an artificial hand in 32 intact-limbed participants. Participants were exposed to four experimental conditions in four counterbalanced blocks: (i) Vision (V) watching an artificial hand positioned congruently to the real hand (out of view); (ii) Vision and strong non-painful TENS in the real hand (V+T); Vision and Stroking (V+S) of the artificial and real hand with a brush; Vision, Stroking and TENS (V+S+T) watching artificial hand being stroked whilst real hand was stroked and receiving TENS. Repeated measure ANOVA detected effects for Condition (P< 0.001), Block (P< 0.001) and Condition x Block interaction (P< 0.001). Pairwise comparisons detected more intense perceptual embodiment for V+S+T compared with V (P< 0.001) and V+T (P< 0.001), and for V+S compared with V (P< 0.001) and V+T (P< 0.001).The intensity of perceptual embodiment increased for later blocks (P< 0.001). A sensation of TENS was generated within the artificial hand in individuals with intact limbs and this facilitated perceptual embodiment. The magnitude of effect was modest.

Transcutaneous electrical nerve stimulation (TENS) accelerates cutaneous wound healing and inhibits pro-inflammatory cytokines.

PubMed

Gürgen, Seren Gülşen; Sayın, Oya; Cetin, Ferihan; Tuç Yücel, Ayşe

2014-06-01

The purpose of this study was to evaluate transcutaneous electrical nerve stimulation (TENS) and other common treatment methods used in the process of wound healing in terms of the expression levels of pro-inflammatory cytokines. In the study, 24 female and 24 male adult Wistar-Albino rats were divided into five groups: (1) the non-wounded group having no incision wounds, (2) the control group having incision wounds, (3) the TENS (2 Hz, 15 min) group, (4) the physiological saline (PS) group and (5) the povidone iodine (PI) group. In the skin sections, interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were assessed with enzyme-linked immunosorbent assay and immunohistochemical methods. In the non-wounded group, the expression of IL-1β, IL-6, and TNF-α signaling molecules was weaker in the whole tissue; however, in the control group, significant inflammatory response occurred, and strong cytokine expression was observed in the dermis, granulation tissue, hair follicles, and sebaceous glands (P < 0.05). In the TENS group, the decrease in TNF-α, IL-1β, and IL-6 immunoreaction in the skin was significant compared to the other forms of treatment (P < 0.05). Distinctive decreases of pro-inflammatory cytokines observed in the dermis in the TENS group suggest that TENS shortened the healing process by inhibating the inflammation phase.

Efficacy of the device combining high-frequency transcutaneous electrical nerve stimulation and thermotherapy for relieving primary dysmenorrhea: a randomized, single-blind, placebo-controlled trial.

PubMed

Lee, Banghyun; Hong, Seung Hwa; Kim, Kidong; Kang, Wee Chang; No, Jae Hong; Lee, Jung Ryeol; Jee, Byung Chul; Yang, Eun Joo; Cha, Eun-Jong; Kim, Yong Beom

2015-11-01

To investigate the efficacy and safety of the combined therapy with high-frequency transcutaneous electrical nerve stimulation (hf-TENS) and thermotherapy in relieving primary dysmenorrheal pain. In this randomized, single-blind, placebo-controlled study, 115 women with moderate or severe primary dysmenorrhea were assigned to the study or control group at a ratio of 1:1. Subjects in the study group used an integrated hf-TENS/thermotherapy device, whereas control subjects used a sham device. A visual analog scale was used to measure pain intensity. Variables related to pain relief, including reduction rate of dysmenorrheal score, were compared between the groups. The dysmenorrheal score was significantly reduced in the study group compared to the control group following the use of the devices. The duration of pain relief was significantly increased in the study group compared to the control group. There were no differences between the groups in the brief pain inventory scores, numbers of ibuprofen tablets taken orally, and World Health Organization quality of life-BREF scores. No adverse events were observed related to the use of the study device. The combination of hf-TENS and thermotherapy was effective in relieving acute pain in women with moderate or severe primary dysmenorrhea. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

[Mechanisms and applications of transcutaneous electrical nerve stimulation in analgesia].

PubMed

Tang, Zheng-Yu; Wang, Hui-Quan; Xia, Xiao-Lei; Tang, Yi; Peng, Wei-Wei; Hu, Li

2017-06-25

Transcutaneous electrical nerve stimulation (TENS), as a non-pharmacological and non-invasive analgesic therapy with low-cost, has been widely used to relieve pain in various clinical applications, by delivering current pulses to the skin area to activate the peripheral nerve fibers. Nevertheless, analgesia induced by TENS varied in the clinical practice, which could be caused by the fact that TENS with different stimulus parameters has different biological mechanisms in relieving pain. Therefore, to advance our understanding of TENS in various basic and clinical studies, we discussed (1) neurophysiological and biochemical mechanisms of TENS-induced analgesia; (2) relevant factors that may influence analgesic effects of TENS from the perspectives of stimulus parameters, including stimulated position, pulse parameters (current intensity, frequency, and pulse width), stimulus duration and used times in each day; and (3) applications of TENS in relieving clinical pain, including post-operative pain, chronic low back pain and labor pain. Finally, we propose that TENS may involve multiple and complex psychological neurophysiological mechanisms, and suggest that different analgesic effects of TENS with different stimulus parameters should be taken into consideration in clinical applications. In addition, to optimize analgesic effect, we recommend that individual-based TENS stimulation parameters should be designed by considering individual differences among patients, e.g., adaptively adjusting the stimulation parameters based on the dynamic ratings of patients' pain.

Adding transcutaneous electrical nerve stimulation to visual scanning training does not enhance treatment effect on hemispatial neglect: a randomized, controlled, double-blind study.

PubMed

Seniów, Joanna; Polanowska, Katarzyna; Leśniak, Marcin; Członkowska, Anna

2016-12-01

Left-sided transcutaneous electrical nerve stimulation (TENS) increases right hemispheric activity, which may improve the rehabilitative outcome of hemispatial neglect. To examine the behavioral effect of electrical stimulation of the nerve afferents of the left hand during early neuropsychological rehabilitation of post-stroke patients with hemispatial neglect. This randomized, controlled, double-blind study included 29 patients (enrolled in the experimental or control group) with left hemispatial neglect after right hemispheric stroke. For 3 weeks, patients received 15 therapeutic sessions involving TENS (active or sham) with a mesh glove applied on the entire left hand during the first 30 minutes of a 45-minute conventional visual scanning training (VST). Signs of hemispatial neglect were assessed using a psychometric test before and after treatment. Univariate analysis of covariance revealed that differences between the control and experimental groups were not significant after treatment (F(1, 22) = 0.294, P = 0.593) when adjusted for pre-treatment scores and time since stroke onset. This suggested that electrical stimulation failed to mitigate the severity of hemispatial neglect symptoms. Our study did not provide evidence of the effectiveness of TENS when added to VST during early rehabilitation for patients with post-stroke hemispatial neglect. Other techniques (applied alone or together) should be sought to improve recovery in this population.

Transcutaneous electrical nerve stimulation (TENS) improves the diabetic cytopathy (DCP) via up-regulation of CGRP and cAMP.

PubMed

Ding, Liucheng; Song, Tao; Yi, Chaoran; Huang, Yi; Yu, Wen; Ling, Lin; Dai, Yutian; Wei, Zhongqing

2013-01-01

The objective of this study was to investigate the effects and mechanism of Transcutaneous Electrical Nerve Stimulation (TENS) on the diabetic cytopathy (DCP) in the diabetic bladder. A total of 45 rats were randomly divided into diabetes mellitus (DM)/TENS group (n=15), DM group (n=15) and control group (n=15). The rats in the DM/TENS and TENS groups were electronically stimulated (stimulating parameters: intensity-31 V, frequency-31 Hz, and duration of stimulation of 15 min) for three weeks. Bladder histology, urodynamics and contractile responses to field stimulation and carbachol were determined. The expression of calcitonin gene-related peptide (CGRP) was analyzed by RT-PCR and Western blotting. The results showed that contractile responses of the DM rats were ameliorated after 3 weeks of TENS. Furthermore, TENS significantly increased bladder wet weight, volume threshold for micturition and reduced PVR, V% and cAMP content of the bladder. The mRNA and protein levels of CGRP in dorsal root ganglion (DRG) in the DM/TENS group were higher than those in the DM group. TENS also significantly up-regulated the cAMP content in the bladder body and base compared with diabetic rats. We conclude that TENS can significantly improve the urine contractility and ameliorate the feeling of bladder fullness in DM rats possibly via up-regulation of cAMP and CGRP in DRG.