Non-destructive testing of concrete.

DOT National Transportation Integrated Search

1979-11-01

This research project was initiated to evaluate the performance of an ultrasonic testing device device in predicting compressive strengths from tests performed on samples of fresh concrete. : The initial phase of this study involved laboratory perora...

Dynamic Response Assessment for the MEMS Accelerometer Under Severe Shock Loads

NASA Technical Reports Server (NTRS)

Fan, Mark S.; Shaw, Harry C.

2001-01-01

NASA Goddard Space Flight Center (GSFC) has evaluated the dynamic response of a commercial-off-the-shelf (COTS) microelectromechanical systems (MEMS) device made by Analog Device, Inc. The device is designated as ADXL250 and is designed mainly for sensing dynamic acceleration. It is also used to measure the tilting angle of any system or component from its original level position. The device has been in commercial use (e.g., in automobile airbag deployment system as a dual-axial accelerometer and in the electronic game play-station as a tilting sensor) with success, but NASA needs an in-depth assessment of its performance under severe dynamic shock environments. It was realized while planning this evaluation task that two assessments would be beneficial to NASA's missions: (1) severe dynamic shock response under nominal thermal environments; and (2) general dynamic performance under cryogenic environments. The first evaluation aims at obtaining a good understanding of its micromachined structure within a framework of brittle fracture dynamics, while the second evaluation focuses on the structure integrity under cryogenic temperature conditions. The information we gathered from the manufacturer indicated that the environmental stresses under NASA's evaluation program have been far beyond what the device has experienced with commercial applications, for which the device was designed. Thus NASA needs the outcome of this evaluation in order to make the selection for possible use for its missions. This paper provides details of the first evaluation the dynamic response under severe multi-axial single-pulse shock load. It was performed using finite element tools with nonlinear dynamics procedures.

Experimental evaluation of cooling efficiency of the high performance cooling device

NASA Astrophysics Data System (ADS)

Nemec, Patrik; Malcho, Milan

2016-06-01

This work deal with experimental evaluation of cooling efficiency of cooling device capable transfer high heat fluxes from electric elements to the surrounding. The work contain description of cooling device, working principle of cooling device, construction of cooling device. Experimental part describe the measuring method of device cooling efficiency evaluation. The work results are presented in graphic visualization of temperature dependence of the contact area surface between cooling device evaporator and electronic components on the loaded heat of electronic components in range from 250 to 740 W and temperature dependence of the loop thermosiphon condenser surface on the loaded heat of electronic components in range from 250 to 740 W.

New evaluation parameter for wearable thermoelectric generators

NASA Astrophysics Data System (ADS)

Wijethunge, Dimuthu; Kim, Woochul

2018-04-01

Wearable devices constitute a key application area for thermoelectric devices. However, owing to new constraints in wearable applications, a few conventional device optimization techniques are not appropriate and material evaluation parameters, such as figure of merit (zT) and power factor (PF), tend to be inadequate. We illustrated the incompleteness of zT and PF by performing simulations and considering different thermoelectric materials. The results indicate a weak correlation between device performance and zT and PF. In this study, we propose a new evaluation parameter, zTwearable, which is better suited for wearable applications compared to conventional zT. Owing to size restrictions, gap filler based device optimization is extremely critical in wearable devices. With respect to the occasions in which gap fillers are used, expressions for power, effective thermal conductivity (keff), and optimum load electrical ratio (mopt) are derived. According to the new parameters, the thermal conductivity of the material has become much more critical now. The proposed new evaluation parameter, namely, zTwearable, is extremely useful in the selection of an appropriate thermoelectric material among various candidates prior to the commencement of the actual design process.

Highway Vehicle Retrofit Evaluation : Phase I. Analysis and Preliminary Evaluation Results. Volume 1. Sections 1 through 3.

DOT National Transportation Integrated Search

1975-11-01

This report in two volumes presents an analysis and preliminary evaluation of selected used-car and light-truck fuel economy retrofit devices. In particular, information is provided that depicts the performance characteristics of retrofit devices tha...

STS-43 Commander Blaha conducts DTO 1208 using laptop on OV-104's flight deck

NASA Image and Video Library

1991-08-11

STS043-03-009 (5 Aug 1991) ---- Astronaut John E. Blaha is pictured executing development test objective (DTO) 1208, Space Station Cursor Control Device Evaluation II and advanced applications. The purpose of the Cursor Control Device Experiment is to evaluate human performance under space flight conditions of cursor control devices which are similar to the devices under consideration for use onboard Space Station computers. Here, the mission commander uses a thumbball/handgrip control device. Each crewmember evaluated the different types of cursor control devices during the nine-day STS-43 mission. Other methods of cursor control evaluated were the built-in trackball, a side mounted trackball with restraints and an optical pad with mouse.

STS-43 MS Adamson conducts DTO 1208 using laptop on OV-104's flight deck

NASA Image and Video Library

1991-08-11

STS043-14-034 (2-11 Aug 1991) --- Astronaut James C. Adamson is pictured executing Development Test Objective (DTO) 1208, Space Station Cursor Control Device Evaluation II and Advanced Applications. The purpose of the Cursor Control Device Experiment is to evaluate human performance under space flight conditions of cursor control devices which are similar to the devices under consideration for use onboard space station computers. Here, the mission specialists uses a thumbball/handgrip control device. Each crewmember evaluated the different types of cursor control devices during the nine-day STS-43 mission. Other methods of cursor control evaluated were the built-in trackball, a side mounted trackball with restraints and an optical pad with mouse.

Evaluating and improving the performance of thin film force sensors within body and device interfaces.

PubMed

Likitlersuang, Jirapat; Leineweber, Matthew J; Andrysek, Jan

2017-10-01

Thin film force sensors are commonly used within biomechanical systems, and at the interface of the human body and medical and non-medical devices. However, limited information is available about their performance in such applications. The aims of this study were to evaluate and determine ways to improve the performance of thin film (FlexiForce) sensors at the body/device interface. Using a custom apparatus designed to load the sensors under simulated body/device conditions, two aspects were explored relating to sensor calibration and application. The findings revealed accuracy errors of 23.3±17.6% for force measurements at the body/device interface with conventional techniques of sensor calibration and application. Applying a thin rigid disc between the sensor and human body and calibrating the sensor using compliant surfaces was found to substantially reduce measurement errors to 2.9±2.0%. The use of alternative calibration and application procedures is recommended to gain acceptable measurement performance from thin film force sensors in body/device applications. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Evaluation of warning lights on maintenance of traffic devices and development of possible alternatives.

DOT National Transportation Integrated Search

2013-07-01

This report documents the efforts and results of a number of studies and evaluations performed by TTI : researchers to evaluate the effect and value of steady-burn warning lights on temporary traffic control : devices used to delineate the correct tr...

How Does Medical Device Regulation Perform in the United States and the European Union? A Systematic Review

PubMed Central

Kramer, Daniel B.; Xu, Shuai; Kesselheim, Aaron S.

2012-01-01

Background Policymakers and regulators in the United States (US) and the European Union (EU) are weighing reforms to their medical device approval and post-market surveillance systems. Data may be available that identify strengths and weakness of the approaches to medical device regulation in these settings. Methods and Findings We performed a systematic review to find empirical studies evaluating medical device regulation in the US or EU. We searched Medline using two nested categories that included medical devices and glossary terms attributable to the US Food and Drug Administration and the EU, following PRISMA guidelines for systematic reviews. We supplemented this search with a review of the US Government Accountability Office online database for reports on US Food and Drug Administration device regulation, consultations with local experts in the field, manual reference mining of selected articles, and Google searches using the same key terms used in the Medline search. We found studies of premarket evaluation and timing (n = 9), studies of device recalls (n = 8), and surveys of device manufacturers (n = 3). These studies provide evidence of quality problems in pre-market submissions in the US, provide conflicting views of device safety based largely on recall data, and relay perceptions of some industry leaders from self-surveys. Conclusions Few studies have quantitatively assessed medical device regulation in either the US or EU. Existing studies of US and EU device approval and post-market evaluation performance suggest that policy reforms are necessary for both systems, including improving classification of devices in the US and promoting transparency and post-market oversight in the EU. Assessment of regulatory performance in both settings is limited by lack of data on post-approval safety outcomes. Changes to these device approval and post-marketing systems must be accompanied by ongoing research to ensure that there is better assessment of what works in either setting. Please see later in the article for the Editors' Summary. PMID:22912563

Regulatory science based approach in development of novel medical devices.

PubMed

Sakuma, Ichiro

2015-08-01

For development rational evaluation method for medical devices' safety and efficacy, regulatory science studies are important. Studies on regulatory affairs related to a medical device under development should be conducted as well as its technological development. Clinical performance of a medical device is influenced by performance of the device, medical doctors' skill, pathological condition of a patient, and so on. Thus it is sometimes difficult to demonstrate superiority of the device in terms of clinical outcome although its efficacy as a medical device is accepted. Setting of appropriate end points is required to evaluate a medical device appropriately. Risk assessment and risk management are the basis of medical device safety assurance. In case of medical device software, there are difficulties in identifying the risk due to its complexity of user environment and different design and manufacturing procedure compared with conventional hardware based medical devices. Recent technological advancement such as information and communication technologies (ICT) for medical devices and wireless network has raised new issue on risk management: cybersecurity. We have to watch closely the progress of safety standard development.

The Captive Helicopter as a Training Device: Experimental Evaluation of a Concept. Technical Report 68-9.

ERIC Educational Resources Information Center

Caro, Paul W., Jr.; And Others

As part of the Army's effort to use synthetic devices to improve training, researchers evaluated a captive helicopter attached to a ground effects machine. Experimental groups received varying amounts of pre-flight practice tasks designed to develop flight skills, while control groups received no device training. Student flight performance during…

Analytic investigation of helicopter rotor blade appended aeroelastic devices

NASA Technical Reports Server (NTRS)

Bielawa, Richard L.

1984-01-01

Analytic evaluations of four different passive aeroelastic devices appended to helicopter rotor blades are presented. The devices consist of a passive tuned tab, a control coupled tab, an all-flying tip and a harmonic dilational airfoil tip. Each device was conceived for improving either aerodynamic performance or reducing vibratory control loads or hub shears. The evaluation was performed using a comprehensive rotor aeroelastic analysis (the G400PA code with appropriate modifications), together with data for a realistic helicopter rotor blade (the UH-60A Blackhawk), in high speed flight (90 m/s, 175 kts). The results of this study show that significant performance (L/(D sub e)) gains can be achieved with the all-flying free tip. Results from the harmonic dilational airfoil tip show the potential for moderate improvements in L/(D sub e). Finally, the results for the passive tuned tab and the control coupled tab, as configured for this study, show these devices to be impractical. Sections are included which describe the operation of each device, the required G400PA modifications, and the detailed results obtained for each device.

EVALUATION OF FOUR NOVEL FINE PARTICULATE COLLECTION DEVICES

EPA Science Inventory

The report gives results of an experimental performance evaluation of four novel fine particulate control devices: the Johns-Manville Cleanable High-Efficiency Air Filtration (CHEAF) System, the APS Electrostatic Scrubber, the APS Electrotube, and the TRW Charged Droplet Scrubber...

What you can't feel won't hurt you: Evaluating haptic hardware using a haptic contrast sensitivity function.

PubMed

Salisbury, C M; Gillespie, R B; Tan, H Z; Barbagli, F; Salisbury, J K

2011-01-01

In this paper, we extend the concept of the contrast sensitivity function - used to evaluate video projectors - to the evaluation of haptic devices. We propose using human observers to determine if vibrations rendered using a given haptic device are accompanied by artifacts detectable to humans. This determination produces a performance measure that carries particular relevance to applications involving texture rendering. For cases in which a device produces detectable artifacts, we have developed a protocol that localizes deficiencies in device design and/or hardware implementation. In this paper, we present results from human vibration detection experiments carried out using three commercial haptic devices and one high performance voice coil motor. We found that all three commercial devices produced perceptible artifacts when rendering vibrations near human detection thresholds. Our protocol allowed us to pinpoint the deficiencies, however, and we were able to show that minor modifications to the haptic hardware were sufficient to make these devices well suited for rendering vibrations, and by extension, the vibratory components of textures. We generalize our findings to provide quantitative design guidelines that ensure the ability of haptic devices to proficiently render the vibratory components of textures.

The performance of child restraint devices in transport airplane passenger seats.

DOT National Transportation Integrated Search

1994-09-01

The performance of child restraint devices (CRDs) in commercial transport airplane passenger seats was evaluated by a dynamic impact test program. Background information on the policies and regulations related to child restraints is summarized. Tests...

21 CFR 26.37 - Confidence building activities.

Code of Federal Regulations, 2010 CFR

2010-04-01

... MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN MEDICAL DEVICE PRODUCT EVALUATION REPORTS: UNITED STATES AND THE EUROPEAN... assessment bodies (CAB's) to perform quality system or product evaluations to the specifications of the...

NASA NDE Applications for Mobile MEMS Devices and Sensors

NASA Technical Reports Server (NTRS)

Wilson, William C.; Atkinson, Gary M.; Barclay, R. O.

2008-01-01

NASA would like new devices and sensors for performing nondestructive evaluation (NDE) of aerospace vehicles. These devices must be small in size/volume, mass, and power consumption. The devices must be autonomous and mobile so they can access the internal structures of aircraft and spacecraft and adequately monitor the structural health of these craft. The platforms must be mobile in order to transport NDE sensors for evaluating structural integrity and determining whether further investigations will be required. Microelectromechanical systems (MEMS) technology is crucial to the development of the mobile platforms and sensor systems. This paper presents NASA s needs for micro mobile platforms and MEMS sensors that will enable NDE to be performed on aerospace vehicles.

Performance of point-of-use devices to remove manganese from drinking water.

PubMed

Carrière, Annie; Brouillon, Manon; Sauvé, Sébastien; Bouchard, Maryse F; Barbeau, Benoit

2011-01-01

A recent epidemiological study reported significant cognitive deficits among children in relation with consumption of water with manganese concentrations in the order of 50-100 ug/L. Concerns for neurotoxic effects of manganese raises the need for evaluating the efficiency of domestic water treatment systems for removal of this metal. The objective of the present study was to determine whether POU devices are efficient at reducing dissolved manganese concentration in drinking water. Various devices were tested according to the NSF 53 protocol for general metals for high pH test water. Based on these assays, the pour-through filters were identified as the most promising POU devices, with dissolved manganese removal greater than 60% at 100% rated capacity, and greater than 45% at 200% rated capacity (influent Mn ≈1,000 μg/L). Under-the-sink filters using cationic exchange resins (i.e., water softeners) were also efficient at removing dissolved manganese but over a shorter operating life. Manganese leaching was also observed beyond their rated capacity, making them less robust treatments. The activated carbon block filters and other proprietary technologies were found to be inappropriate for dissolved manganese removal. Further evaluation of POU devices performance should evaluate the impact of hardness on process performance. The impact of particulate Mn should also be evaluated.

Evaluation of the leap motion controller as a new contact-free pointing device.

PubMed

Bachmann, Daniel; Weichert, Frank; Rinkenauer, Gerhard

2014-12-24

This paper presents a Fitts' law-based analysis of the user's performance in selection tasks with the Leap Motion Controller compared with a standard mouse device. The Leap Motion Controller (LMC) is a new contact-free input system for gesture-based human-computer interaction with declared sub-millimeter accuracy. Up to this point, there has hardly been any systematic evaluation of this new system available. With an error rate of 7.8% for the LMC and 2.8% for the mouse device, movement times twice as large as for a mouse device and high overall effort ratings, the Leap Motion Controller's performance as an input device for everyday generic computer pointing tasks is rather limited, at least with regard to the selection recognition provided by the LMC.

Evaluation of the Leap Motion Controller as a New Contact-Free Pointing Device

PubMed Central

Bachmann, Daniel; Weichert, Frank; Rinkenauer, Gerhard

2015-01-01

This paper presents a Fitts' law-based analysis of the user's performance in selection tasks with the Leap Motion Controller compared with a standard mouse device. The Leap Motion Controller (LMC) is a new contact-free input system for gesture-based human-computer interaction with declared sub-millimeter accuracy. Up to this point, there has hardly been any systematic evaluation of this new system available. With an error rate of 7.8 % for the LMC and 2.8% for the mouse device, movement times twice as large as for a mouse device and high overall effort ratings, the Leap Motion Controller's performance as an input device for everyday generic computer pointing tasks is rather limited, at least with regard to the selection recognition provided by the LMC. PMID:25609043

Platform for efficient switching between multiple devices in the intensive care unit.

PubMed

De Backere, F; Vanhove, T; Dejonghe, E; Feys, M; Herinckx, T; Vankelecom, J; Decruyenaere, J; De Turck, F

2015-01-01

This article is part of the Focus Theme of METHODS of Information in Medicine on "Managing Interoperability and Complexity in Health Systems". Handheld computers, such as tablets and smartphones, are becoming more and more accessible in the clinical care setting and in Intensive Care Units (ICUs). By making the most useful and appropriate data available on multiple devices and facilitate the switching between those devices, staff members can efficiently integrate them in their workflow, allowing for faster and more accurate decisions. This paper addresses the design of a platform for the efficient switching between multiple devices in the ICU. The key functionalities of the platform are the integration of the platform into the workflow of the medical staff and providing tailored and dynamic information at the point of care. The platform is designed based on a 3-tier architecture with a focus on extensibility, scalability and an optimal user experience. After identification to a device using Near Field Communication (NFC), the appropriate medical information will be shown on the selected device. The visualization of the data is adapted to the type of the device. A web-centric approach was used to enable extensibility and portability. A prototype of the platform was thoroughly evaluated. The scalability, performance and user experience were evaluated. Performance tests show that the response time of the system scales linearly with the amount of data. Measurements with up to 20 devices have shown no performance loss due to the concurrent use of multiple devices. The platform provides a scalable and responsive solution to enable the efficient switching between multiple devices. Due to the web-centric approach new devices can easily be integrated. The performance and scalability of the platform have been evaluated and it was shown that the response time and scalability of the platform was within an acceptable range.

40 CFR 610.10 - Program purpose.

Code of Federal Regulations, 2013 CFR

2013-07-01

... DEVICES Test Procedures and Evaluation Criteria General Provisions § 610.10 Program purpose. (a) The... standardized procedures, the performance of various retrofit devices applicable to automobiles for which fuel... statistical analysis of data from vehicle tests, the evaluation program will determine the effects on fuel...

40 CFR 610.10 - Program purpose.

Code of Federal Regulations, 2014 CFR

2014-07-01

... DEVICES Test Procedures and Evaluation Criteria General Provisions § 610.10 Program purpose. (a) The... standardized procedures, the performance of various retrofit devices applicable to automobiles for which fuel... statistical analysis of data from vehicle tests, the evaluation program will determine the effects on fuel...

40 CFR 610.10 - Program purpose.

Code of Federal Regulations, 2011 CFR

2011-07-01

... DEVICES Test Procedures and Evaluation Criteria General Provisions § 610.10 Program purpose. (a) The... standardized procedures, the performance of various retrofit devices applicable to automobiles for which fuel... statistical analysis of data from vehicle tests, the evaluation program will determine the effects on fuel...

40 CFR 610.10 - Program purpose.

Code of Federal Regulations, 2012 CFR

2012-07-01

... DEVICES Test Procedures and Evaluation Criteria General Provisions § 610.10 Program purpose. (a) The... standardized procedures, the performance of various retrofit devices applicable to automobiles for which fuel... statistical analysis of data from vehicle tests, the evaluation program will determine the effects on fuel...

Randomized in vitro and in vivo evaluation of different biopsy needles and devices for breast biopsy.

PubMed

Helbich, T H; Rudas, M; Böhm, G; Huber, S; Wagner, T; Taucher, S; Wolf, G; Mostbeck, G H

1999-01-01

In an experimental study (in vitro and in vivo) we evaluated the efficacy of various biopsy needles/devices for breast biopsy. In vitro, biopsies of five human cadaveric breast specimens were performed using 33 different needles/devices ranging from 14 to 20-gauge. Of these 33 needles/devices, 22 optimally performing needles were selected for the in vivo study. In the clinical part of the study, 44 breast lesions were randomly biopsied with each of the 22 needles/devices under stereotactic guidance. Tissue specimens were analysed quantitatively and qualitatively. Several automatic long-throw guns (Acecut, Asap, Biopty, Magnum) obtained greater tissue areas and had a better histopathologic score than the conventional type of a side-notch needle like Trucut, an aspiration needle like Surecut, or an end-cut needle like Autovac. The automatic long-throw guns performed better than the short-throw Monopty gun. Regardless of needle size (14-20-gauge), breast biopsies should be routinely performed with automated long-throw side-notch guns (Acecut, Asap, Biopty, Magnum).

On the design of a miniature haptic ring for cutaneous force feedback using shape memory alloy actuators

NASA Astrophysics Data System (ADS)

Hwang, Donghyun; Lee, Jaemin; Kim, Keehoon

2017-10-01

This paper proposes a miniature haptic ring that can display touch/pressure and shearing force to the user’s fingerpad. For practical use and wider application of the device, it is developed with the aim of achieving high wearability and mobility/portability as well as cutaneous force feedback functionality. A main body of the device is designed as a ring-shaped lightweight structure with a simple driving mechanism, and thin shape memory alloy (SMA) wires having high energy density are applied as actuating elements. Also, based on a band-type wireless control unit including a wireless data communication module, the whole device could be realized as a wearable mobile haptic device system. These features enable the device to take diverse advantages on functional performances and to provide users with significant usability. In this work, the proposed miniature haptic ring is systematically designed, and its working performances are experimentally evaluated with a fabricated functional prototype. The experimental results obviously demonstrate that the proposed device exhibits higher force-to-weight ratio than conventional finger-wearable haptic devices for cutaneous force feedback. Also, it is investigated that operational performances of the device are strongly influenced by electro-thermomechanical behaviors of the SMA actuator. In addition to the experiments for performance evaluation, we conduct a preliminary user test to assess practical feasibility and usability based on user’s qualitative feedback.

Acquisition and evaluation of Hamburg wheel-tracking device

DOT National Transportation Integrated Search

1999-04-01

Surrogate performance tests, or "proof" tests, for asphalt mixtures are being evaluated by states to gauge mixture performance potential in the lab. The University of Arkansas constructed, ERSA (Evaluator of Rutting and Stripping in Asphalt) to "scre...

Evaluation of advanced cooling therapy's esophageal cooling device for core temperature control.

PubMed

Naiman, Melissa; Shanley, Patrick; Garrett, Frank; Kulstad, Erik

2016-05-01

Managing core temperature is critical to patient outcomes in a wide range of clinical scenarios. Previous devices designed to perform temperature management required a trade-off between invasiveness and temperature modulation efficiency. The Esophageal Cooling Device, made by Advanced Cooling Therapy (Chicago, IL), was developed to optimize warming and cooling efficiency through an easy and low risk procedure that leverages heat transfer through convection and conduction. Clinical data from cardiac arrest, fever, and critical burn patients indicate that the Esophageal Cooling Device performs very well both in terms of temperature modulation (cooling rates of approximately 1.3°C/hour, warming of up to 0.5°C/hour) and maintaining temperature stability (variation around goal temperature ± 0.3°C). Physicians have reported that device performance is comparable to the performance of intravascular temperature management techniques and superior to the performance of surface devices, while avoiding the downsides associated with both.

Fabrication and Performance of Large Format Transition Edge Sensor Microcalorimeter Arrays

NASA Technical Reports Server (NTRS)

Chervenak, James A.; Adams, James S.; Bandler, Simon R.; Busch, Sara E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, Jan-Patrick;

Friction-reducing devices for lateral patient transfers: a clinical evaluation.

PubMed

Baptiste, Andrea; Boda, Sruthi V; Nelson, Audrey L; Lloyd, John D; Lee, William E

2006-04-01

The purpose of this study was to assess the performance of lateral transfer devices compared with the traditional draw sheet method in acute care settings through subjective feedback of caregivers actually using the devices. Every 2 weeks, the eight participating acute care units each received one of the devices, which had been randomly selected. Data were collected through caregiver surveys, which rated comfort, ease of use, perceived injury risk, time efficiency, and patient safety. An overall performance rating was calculated as the sum of these five categories. Caregivers rated air-assisted devices significantly higher (p < .05) than other devices. Lateral transfer devices are recommended over the traditional draw sheet method for performing lateral patient transfers. These friction-reducing devices are a cost-effective solution to the load of lateral patient transfers and should be favorably considered when purchasing patient-handling technologies.

Cost and Information Effectiveness Analysis (CIEA): A Methodology for Evaluating a Training Device Operational Readiness Assessment Capability (DORAC).

DTIC Science & Technology

1981-02-01

Report 528 COST AIND I*FO•?JidTH ?i EFFECT•• ES1BS ANALYSIS (CDEA): A METiBLOBU Y FOR EVALUATIN1G A TRAINING DEMCE OPERATMDN1AL MAEA3 ],SE 3SSESS$ iElT ...8217, N. Within a military setting, the uses of training devices in performance evaluation have generally mirrored civilian uses and primarily...Technical Report 528 COST AND INFORMATION EFFECTIVENESS ANALYSIS (CIEA): A METHODOLOGY FOR EVALUATING A TRAINING DEVICE OPERATIONAL READINESS

Perceptions of transcatheter device closure of patent ductus arteriosus in veterinary cardiology and evaluation of a canine model to simulate device placement: a preliminary study.

PubMed

Saunders, A B; Keefe, L; Birch, S A; Wierzbicki, M A; Maitland, D J

2017-06-01

The purpose of this study was to evaluate a canine patent ductus arteriosus (PDA) model developed for practicing device placement and to determine practices and perceptions regarding transcatheter closure of PDA from the veterinary cardiology community. A silicone model was developed from images obtained from a dog with a PDA and device placement was performed with catheter equipment and a document camera to simulate fluoroscopy. A total of 36 individuals including 24 diplomates and 12 residents participated, and the feedback was obtained. The study included an initial questionnaire, practice with the model, observation of device placement using the model, and a follow-up questionnaire. A total of 92% of participants including 100% of residents indicated they did not have the opportunity to practice device placement before performing the procedure and obtained knowledge of the procedure from reading journal articles or observation. Participants indicated selecting the appropriate device size (30/36, 83%) and ensuring the device is appropriately positioned before release (18/36, 50%) as the most common areas of difficulty with device placement. Confidence level was higher after practicing with the model for residents when compared with diplomates and for participants that had performed 1-15 procedures when compared with those that had performed >15 procedures. These findings suggest those that have performed fewer procedures may benefit the most from practicing with a model. This preliminary study demonstrates the feasibility of a PDA model for practicing device placement and suggests that there is a potential benefit from providing additional training resources. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of Evaluative Devices for Adequate Assessment of Levels of Competence in Certain Physical Education Activities. Final Report.

ERIC Educational Resources Information Center

Wilson, Ruth M.

This investigation sought to study separately evaluative devices for assessing levels of performance and knowledge competency in basketball, swimming, and gymnastics. Subjects were women students at the University of Washington, 1968-69. For assessment of basketball competence, indications are that: (1) evaluation, by one individual, of films of…

Prediction and measurement results of radiation damage to CMOS devices on board spacecraft

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Danchenko, V.; Cliff, R. A.; Sing, M.; Brucker, G. J.; Ohanian, R. S.

1977-01-01

Final results from the CMOS Radiation Effects Measurement (CREM) experiment flown on Explorer 55 are presented and discussed, based on about 15 months of observations and measurements. Conclusions are given relating to long-range annealing, effects of operating temperature on semiconductor performance in space, biased and unbiased P-MOS device degradation, unbiased n-channel device performance, changes in device transconductance, and the difference in ionization efficiency between Co-60 gamma rays and 1-Mev Van de Graaff electrons. The performance of devices in a heavily shielded electronic subsystem box within the spacecraft is evaluated and compared. Environment models and computational methods and their impact on device-degradation estimates are being reviewed to determine whether they permit cost-effective design of spacecraft.

Electroacoustic verification of frequency modulation systems in cochlear implant users.

PubMed

Fidêncio, Vanessa Luisa Destro; Jacob, Regina Tangerino de Souza; Tanamati, Liége Franzini; Bucuvic, Érika Cristina; Moret, Adriane Lima Mortari

2017-12-26

The frequency modulation system is a device that helps to improve speech perception in noise and is considered the most beneficial approach to improve speech recognition in noise in cochlear implant users. According to guidelines, there is a need to perform a check before fitting the frequency modulation system. Although there are recommendations regarding the behavioral tests that should be performed at the fitting of the frequency modulation system to cochlear implant users, there are no published recommendations regarding the electroacoustic test that should be performed. Perform and determine the validity of an electroacoustic verification test for frequency modulation systems coupled to different cochlear implant speech processors. The sample included 40 participants between 5 and 18 year's users of four different models of speech processors. For the electroacoustic evaluation, we used the Audioscan Verifit device with the HA-1 coupler and the listening check devices corresponding to each speech processor model. In cases where the transparency was not achieved, a modification was made in the frequency modulation gain adjustment and we used the Brazilian version of the "Phrases in Noise Test" to evaluate the speech perception in competitive noise. It was observed that there was transparency between the frequency modulation system and the cochlear implant in 85% of the participants evaluated. After adjusting the gain of the frequency modulation receiver in the other participants, the devices showed transparency when the electroacoustic verification test was repeated. It was also observed that patients demonstrated better performance in speech perception in noise after a new adjustment, that is, in these cases; the electroacoustic transparency caused behavioral transparency. The electroacoustic evaluation protocol suggested was effective in evaluation of transparency between the frequency modulation system and the cochlear implant. Performing the adjustment of the speech processor and the frequency modulation system gain are essential when fitting this device. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Thermal Analysis of a Disposable, Instrument-Free DNA Amplification Lab-on-a-Chip Platform.

PubMed

Pardy, Tamás; Rang, Toomas; Tulp, Indrek

2018-06-04

Novel second-generation rapid diagnostics based on nucleic acid amplification tests (NAAT) offer performance metrics on par with clinical laboratories in detecting infectious diseases at the point of care. The diagnostic assay is typically performed within a Lab-on-a-Chip (LoC) component with integrated temperature regulation. However, constraints on device dimensions, cost and power supply inherent with the device format apply to temperature regulation as well. Thermal analysis on simplified thermal models for the device can help overcome these barriers by speeding up thermal optimization. In this work, we perform experimental thermal analysis on the simplified thermal model for our instrument-free, single-use LoC NAAT platform. The system is evaluated further by finite element modelling. Steady-state as well as transient thermal analysis are performed to evaluate the performance of a self-regulating polymer resin heating element in the proposed device geometry. Reaction volumes in the target temperature range of the amplification reaction are estimated in the simulated model to assess compliance with assay requirements. Using the proposed methodology, we demonstrated our NAAT device concept capable of performing loop-mediated isothermal amplification in the 20⁻25 °C ambient temperature range with 32 min total assay time.

Quantification of error associated with stormwater and wastewater flow measurement devices

EPA Science Inventory

A novel flow testbed has been designed to evaluate the performance of flumes as flow measurement devices. The newly constructed testbed produces both steady and unsteady flows ranging from 10 to 1500 gpm. Two types of flumes (Parshall and trapezoidal) are evaluated under differen...

Phase III gross solids removal devices pilot study, 2002-2005.

DOT National Transportation Integrated Search

2005-12-01

The objective of the Phase III Gross Solids Removal Devices (GSRDs) Pilot study was to : evaluate the performance of non-proprietary devices that can capture gross solids and that can be : incorporated into existing highway drainage systems or implem...

76 FR 48169 - Advancing Regulatory Science for Highly Multiplexed Microbiology/Medical Countermeasure Devices...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

...] Advancing Regulatory Science for Highly Multiplexed Microbiology/ Medical Countermeasure Devices; Public... Regulatory Science for Highly Multiplexed Microbiology/Medical Countermeasure Devices.'' The purpose of the public meeting is to discuss performance evaluation of highly multiplexed microbiology/medical...

40 CFR Appendix A to Subpart Ll of... - Applicability of General Provisions

Code of Federal Regulations, 2010 CFR

2010-07-01

... not require CMS or CMS performance evaluation. 63.8(e) Performance evaluation for CMS No 63.9(b)(1)-(5... evaluations No Subpart LL does not require performance evaluation for CMS. 63.11(a)-(b) Control device... Appendix A to Subpart LL of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

Blood transfer devices for malaria rapid diagnostic tests: evaluation of accuracy, safety and ease of use.

PubMed

Hopkins, Heidi; Oyibo, Wellington; Luchavez, Jennifer; Mationg, Mary Lorraine; Asiimwe, Caroline; Albertini, Audrey; González, Iveth J; Gatton, Michelle L; Bell, David

2011-02-08

Malaria rapid diagnostic tests (RDTs) are increasingly used by remote health personnel with minimal training in laboratory techniques. RDTs must, therefore, be as simple, safe and reliable as possible. Transfer of blood from the patient to the RDT is critical to safety and accuracy, and poses a significant challenge to many users. Blood transfer devices were evaluated for accuracy and precision of volume transferred, safety and ease of use, to identify the most appropriate devices for use with RDTs in routine clinical care. Five devices, a loop, straw-pipette, calibrated pipette, glass capillary tube, and a new inverted cup device, were evaluated in Nigeria, the Philippines and Uganda. The 227 participating health workers used each device to transfer blood from a simulated finger-prick site to filter paper. For each transfer, the number of attempts required to collect and deposit blood and any spilling of blood during transfer were recorded. Perceptions of ease of use and safety of each device were recorded for each participant. Blood volume transferred was calculated from the area of blood spots deposited on filter paper. The overall mean volumes transferred by devices differed significantly from the target volume of 5 microliters (p < 0.001). The inverted cup (4.6 microliters) most closely approximated the target volume. The glass capillary was excluded from volume analysis as the estimation method used is not compatible with this device. The calibrated pipette accounted for the largest proportion of blood exposures (23/225, 10%); exposures ranged from 2% to 6% for the other four devices. The inverted cup was considered easiest to use in blood collection (206/226, 91%); the straw-pipette and calibrated pipette were rated lowest (143/225 [64%] and 135/225 [60%] respectively). Overall, the inverted cup was the most preferred device (72%, 163/227), followed by the loop (61%, 138/227). The performance of blood transfer devices varied in this evaluation of accuracy, blood safety, ease of use, and user preference. The inverted cup design achieved the highest overall performance, while the loop also performed well. These findings have relevance for any point-of-care diagnostics that require blood sampling.

Comparative ex vivo evaluation of two electronic percussive testing devices measuring the stability of dental implants.

PubMed

Geckili, Onur; Bilhan, Hakan; Cilingir, Altug; Bilmenoglu, Caglar; Ates, Gokcen; Urgun, Aliye Ceren; Bural, Canan

2014-12-01

A comparative ex vivo study was performed to determine electronic percussive test values (PTVs) measured by cabled and wireless electronic percussive testing (EPT) devices and to evaluate the intra- and interobserver reliability of the wireless EPT device. Forty implants were inserted into the vertebrae and forty into the pelvis of a steer, a safe distance apart. The implants were all 4.3 mm wide and 13 mm long, from the same manufacturer. PTV of each implant was measured by four different examiners, using both EPT devices, and compared. Additionally, the intra- and interobserver reliability of the wireless EPT device was evaluated. Statistically significant differences (P <0.05) were observed between PTVs made by the two EPT devices. PTVs measured by the wireless EPT device were significantly higher than the cabled EPT device (P <0.05), indicating lower implant stability. The intraobserver reliability of the wireless EPT device was evaluated as excellent for the measurements in type II bone and good-to-excellent in type IV bone; interobserver reliability was evaluated as fair-to-good in both bone types. The wireless EPT device gives PTVs higher than the cabled EPT device, indicating lower implant stability, and its inter- and intraobserver reliability is good and acceptable.

Medical-device risk management and public safety: using cost-benefit as a measurement of effectiveness

NASA Astrophysics Data System (ADS)

Hughes, Allen A.

1994-12-01

Public safety can be enhanced through the development of a comprehensive medical device risk management. This can be accomplished through case studies using a framework that incorporates cost-benefit analysis in the evaluation of risk management attributes. This paper presents a framework for evaluating the risk management system for regulatory Class III medical devices. The framework consists of the following sixteen attributes of a comprehensive medical device risk management system: fault/failure analysis, premarket testing/clinical trials, post-approval studies, manufacturer sponsored hospital studies, product labeling, establishment inspections, problem reporting program, mandatory hospital reporting, medical literature surveillance, device/patient registries, device performance monitoring, returned product analysis, autopsy program, emergency treatment funds/interim compensation, product liability, and alternative compensation mechanisms. Review of performance histories for several medical devices can reveal the value of information for many attributes, and also the inter-dependencies of the attributes in generating risk information flow. Such an information flow network is presented as a starting point for enhancing medical device risk management by focusing on attributes with high net benefit values and potential to spur information dissemination.

Performance evaluation of photoacoustic oximetry imaging systems using a dynamic blood flow phantom with tunable oxygen saturation

NASA Astrophysics Data System (ADS)

Vogt, William C.; Zhou, Xuewen; Andriani, Rudy; Wear, Keith A.; Garra, Brian S.; Pfefer, Joshua

2018-02-01

Photoacoustic Imaging (PAI) is an emerging technology with strong potential for broad clinical applications from breast cancer detection to cerebral monitoring due to its ability to compute maps of blood oxygen saturation (SO2) distribution in deep tissues using multispectral imaging. However, no well-validated consensus test methods currently exist for evaluating oximetry-specific performance characteristics of PAI devices. We have developed a phantombased flow system capable of rapid SO2 adjustment to serve as a test bed for elucidation of factors impacting SO2 measurement and quantitative characterization of device performance. The flow system is comprised of a peristaltic pump, membrane oxygenator, oxygen and nitrogen gas, and in-line oxygen, pH, and temperature sensors that enable real-time estimation of SO2 reference values. Bovine blood was delivered through breast-relevant tissue phantoms containing vessel-mimicking fluid channels, which were imaged using a custom multispectral PAI system. Blood was periodically drawn for SO2 measurement in a clinical-grade CO-oximeter. We used this flow phantom system to evaluate the impact of device parameters (e.g.,wavelength-dependent fluence corrections) and tissue parameters (e.g. fluid channel depth, blood SO2, spectral coloring artifacts) on oximetry measurement accuracy. Results elucidated key challenges in PAI oximetry and device design trade-offs, which subsequently allowed for optimization of system performance. This approach provides a robust benchtop test platform that can support PAI oximetry device optimization, performance validation, and clinical translation, and may inform future development of consensus test methods for performance assessment of photoacoustic oximetry imaging systems.

Performance impact of dynamic surface coatings on polymeric insulator-based dielectrophoretic particle separators.

PubMed

Davalos, Rafael V; McGraw, Gregory J; Wallow, Thomas I; Morales, Alfredo M; Krafcik, Karen L; Fintschenko, Yolanda; Cummings, Eric B; Simmons, Blake A

2008-02-01

Efficient and robust particle separation and enrichment techniques are critical for a diverse range of lab-on-a-chip analytical devices including pathogen detection, sample preparation, high-throughput particle sorting, and biomedical diagnostics. Previously, using insulator-based dielectrophoresis (iDEP) in microfluidic glass devices, we demonstrated simultaneous particle separation and concentration of various biological organisms, polymer microbeads, and viruses. As an alternative to glass, we evaluate the performance of similar iDEP structures produced in polymer-based microfluidic devices. There are numerous processing and operational advantages that motivate our transition to polymers such as the availability of numerous innate chemical compositions for tailoring performance, mechanical robustness, economy of scale, and ease of thermoforming and mass manufacturing. The polymer chips we have evaluated are fabricated through an injection molding process of the commercially available cyclic olefin copolymer Zeonor 1060R. This publication is the first to demonstrate insulator-based dielectrophoretic biological particle differentiation in a polymeric device injection molded from a silicon master. The results demonstrate that the polymer devices achieve the same performance metrics as glass devices. We also demonstrate an effective means of enhancing performance of these microsystems in terms of system power demand through the use of a dynamic surface coating. We demonstrate that the commercially available nonionic block copolymer surfactant, Pluronic F127, has a strong interaction with the cyclic olefin copolymer at very low concentrations, positively impacting performance by decreasing the electric field necessary to achieve particle trapping by an order of magnitude. The presence of this dynamic surface coating, therefore, lowers the power required to operate such devices and minimizes Joule heating. The results of this study demonstrate that iDEP polymeric microfluidic devices with surfactant coatings provide an affordable engineering strategy for selective particle enrichment and sorting.

Evaluation of a Pour-Through Water Treatment Device for Use as Microbiological Purifier

EPA Science Inventory

The United States Environmental Protection Agency (EPA) Office of Research and Development has evaluated the performance of a Point-of-Use (POU) pour-through device designed for use in India, developing and emerging market (D&E) countries, and under emergency situations in the Un...

Phase IV gross solids removal devices pilot study, 2004-2005.

DOT National Transportation Integrated Search

2005-12-01

The objective of the Phase IV Gross Solids Removal Device (GSRD) Pilot study was to evaluate : the performance of one non-proprietary device that can capture gross solids and that can be : incorporated into existing highway drainage systems or implem...

76 FR 71982 - Advancing Regulatory Science for Highly Multiplexed Microbiology/Medical Countermeasure Devices...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-21

...] Advancing Regulatory Science for Highly Multiplexed Microbiology/ Medical Countermeasure Devices; Public... Multiplexed Microbiology/ Medical Countermeasure Devices'' that published in the Federal Register of August 8... the October 13, 2011, meeting, including the performance evaluation of highly multiplexed microbiology...

Achievements and perspectives of fiber gyros

NASA Astrophysics Data System (ADS)

Boehm, Manfred

1986-01-01

After evaluating the development history and current status of fiber-optic gyros employing the Sagnac effect, attention is given to a novel class of inertial fiber-optic motion devices having their basis in the Kennedy-Thorndike (1932) interferometry experiments. These devices promise high performance strapdown inertial navigation systems that dispense with accelerometers. The prospective performance of such devices is discussed in light of an analysis of Sagnac, Michelson, and Kennedy-Thorndike interferometers.

Evaluation of pavement marking performance.

DOT National Transportation Integrated Search

2008-06-01

The objective of the investigation was to evaluate the useful life of pavement markings. The Manual on Uniform Traffic Control Devices (MUTCD) provides general guidelines for the application and installation of pavement markings. However, performance...

A new global and comprehensive model for ICU ventilator performances evaluation.

PubMed

Marjanovic, Nicolas S; De Simone, Agathe; Jegou, Guillaume; L'Her, Erwan

2017-12-01

This study aimed to provide a new global and comprehensive evaluation of recent ICU ventilators taking into account both technical performances and ergonomics. Six recent ICU ventilators were evaluated. Technical performances were assessed under two FIO 2 levels (100%, 50%), three respiratory mechanics combinations (Normal: compliance [C] = 70 mL cmH 2 O -1 /resistance [R] = 5 cmH 2 O L -1  s -1 ; Restrictive: C = 30/R = 10; Obstructive: C = 120/R = 20), four exponential levels of leaks (from 0 to 12.5 L min -1 ) and three levels of inspiratory effort (P0.1 = 2, 4 and 8 cmH 2 O), using an automated test lung. Ergonomics were evaluated by 20 ICU physicians using a global and comprehensive model involving physiological response to stress measurements (heart rate, respiratory rate, tidal volume variability and eye tracking), psycho-cognitive scales (SUS and NASA-TLX) and objective tasks completion. Few differences in terms of technical performance were observed between devices. Non-invasive ventilation modes had a huge influence on asynchrony occurrence. Using our global model, either objective tasks completion, psycho-cognitive scales and/or physiological measurements were able to depict significant differences in terms of devices' usability. The level of failure that was observed with some devices depicted the lack of adaptation of device's development to end users' requests. Despite similar technical performance, some ICU ventilators exhibit low ergonomics performance and a high risk of misusage.

Community Energy Storage Thermal Analysis and Management: Cooperative Research and Development Final Report, CRADA Number CRD-11-445

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

Smith, Kandler A.

The goal of this project is to create thermal solutions and models for community energy storage devices using both purpose-designed batteries and EV or PHEV batteries. Modeling will be employed to identify major factors of a device's lifetime and performance. Simultaneously, several devices will be characterized to determine their electrical and thermal performance under controlled conditions. After the factors are identified, a variety of thermal design approaches will be evaluated to improve the performance of energy storage devices. Upon completion of this project, recommendations for community energy storage device enclosures, thermal management systems, and/or battery sourcing will be made. NREL'smore » interest is in both new and aged batteries.« less

A Comprehensive Approach for the Ergonomic Evaluation of 13 Emergency and Transport Ventilators.

PubMed

Marjanovic, Nicolas; L'Her, Erwan

2016-05-01

Mechanical ventilation is an important part of emergency medicine and is frequently used for transportation. Human errors during ventilator settings are frequent and may be associated with high morbidity/mortality. The aim of the study was to provide a complete ergonomic evaluation of emergency and transport ventilators, taking into account objective and subjective human-machine interface assessments and individual mental work load. We performed a prospective bench ergonomic evaluation of 13 emergency and transport ventilators, using standardized conditions and a global methodological approach. The study was performed in an evaluation laboratory dedicated to respiratory care, and 12 emergency physicians unfamiliar with the tested devices were included in the evaluation. The ventilators were classified into 3 categories (simple, sophisticated, and ICU-like). Objective chronometric evaluations were conducted considering 9 tasks, and subjective evaluations were performed (ease of use, willingness to use, and user-friendliness of monitoring) using Likert scales. Mental work load evaluation was performed using the NASA Task Load Index scale. Overall task failure rate represented 4% of all attempts. Setting modifications, ventilation mode changes, and powering down durations were different between simple and other emergency and transport ventilator categories (P < .005). There was no difference between ventilator categories for the ease of use and user-friendliness of the monitoring. In contrast, the willingness to use was lower for simple devices, compared with sophisticated and ICU-like emergency and transport ventilators (2.9 ± 1.4 vs 3.9 ± 1.2, P = .002 and 4.3 ± 1, P < .001). No differences were observed between devices regarding the mental work load, except for several specific devices in the sophisticated category. A comprehensive ergonomic evaluation provides valuable information while investigating operational friendliness in emergency and transport ventilators. The choice of a device not only depends on its technical characteristics but should take into account its clinical operational setting and ergonomics in order to decrease mental work load. Sophisticated emergency and transport ventilators should only be used by clinicians who demonstrate expertise in mechanical ventilation. Copyright © 2016 by Daedalus Enterprises.

I/O performance evaluation of a Linux-based network-attached storage device

NASA Astrophysics Data System (ADS)

Sun, Zhaoyan; Dong, Yonggui; Wu, Jinglian; Jia, Huibo; Feng, Guanping

2002-09-01

In a Local Area Network (LAN), clients are permitted to access the files on high-density optical disks via a network server. But the quality of read service offered by the conventional server is not satisfied because of the multiple functions on the server and the overmuch caller. This paper develops a Linux-based Network-Attached Storage (NAS) server. The Operation System (OS), composed of an optimized kernel and a miniaturized file system, is stored in a flash memory. After initialization, the NAS device is connected into the LAN. The administrator and users could configure the access the server through the web page respectively. In order to enhance the quality of access, the management of buffer cache in file system is optimized. Some benchmark programs are peformed to evaluate the I/O performance of the NAS device. Since data recorded in optical disks are usually for reading accesses, our attention is focused on the reading throughput of the device. The experimental results indicate that the I/O performance of our NAS device is excellent.

A novel cuffless device for self-measurement of blood pressure: concept, performance and clinical validation.

PubMed

Boubouchairopoulou, N; Kollias, A; Chiu, B; Chen, B; Lagou, S; Anestis, P; Stergiou, G S

2017-07-01

A pocket-size cuffless electronic device for self-measurement of blood pressure (BP) has been developed (Freescan, Maisense Inc., Zhubei, Taiwan). The device estimates BP within 10 s using three embedded electrodes and one force sensor that is applied over the radial pulse to evaluate the pulse wave. Before use, basic anthropometric characteristics are recorded on the device, and individualized initial calibration is required based on a standard BP measurement performed using an upper-arm BP monitor. The device performance in providing valid BP readings was evaluated in 313 normotensive and hypertensive adults in three study phases during which the device sensor was upgraded. A formal validation study of a prototype device against mercury sphygmomanometer was performed according to the American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 2013 protocol. The test device succeeded in obtaining a valid BP measurement (three successful readings within up to five attempts) in 55-72% of the participants, which reached 87% with device sensor upgrade. For the validation study, 125 adults were recruited and 85 met the protocol requirements for inclusion. The mean device-observers BP difference was 3.2±6.7 (s.d.) mm Hg for systolic and 2.6±4.6 mm Hg for diastolic BP (criterion 1). The estimated s.d. (inter-subject variability) were 5.83 and 4.17 mm Hg respectively (criterion 2). These data suggest that this prototype cuffless BP monitor provides valid self-measurements in the vast majority of adults, and satisfies the BP measurement accuracy criteria of the ANSI/AAMI/ISO 2013 validation protocol.

Emergency department evaluation after conducted energy weapon use: review of the literature for the clinician.

PubMed

Vilke, Gary M; Bozeman, William P; Chan, Theodore C

2011-05-01

Conductive energy weapons (CEWs) are used daily by law enforcement, and patients are often brought to an emergency department (ED) for medical clearance. To review the medical literature on the topic of CEWs and to offer evidence-based recommendations to Emergency Physicians for evaluation and treatment of patients who have received a CEW exposure. A MEDLINE literature search from 1988 to 2010 was performed and limited to human studies published from January 1988 to January 20, 2010 for English language articles with the following keywords: TASER, conductive energy device(s), electronic weapon(s), conductive energy weapon(s), non-lethal weapon(s), conducted energy device(s), conducted energy weapon(s), conductive electronic device(s), and electronic control device(s). Studies identified then underwent a structured review from which results could be evaluated. There were 140 articles on CEWs screened, and 20 appropriate articles were rigorously reviewed and recommendations given. These studies did not report any evidence of dangerous laboratory abnormalities, physiologic changes, or immediate or delayed cardiac ischemia or dysrhythmias after exposure to CEW electrical discharges of up to 15 s. The current medical literature does not support routine performance of laboratory studies, electrocardiograms, or prolonged ED observation or hospitalization for ongoing cardiac monitoring after CEW exposure in an otherwise asymptomatic awake and alert patient. Copyright © 2011 Elsevier Inc. All rights reserved.

Phantom-based evaluation method for surgical assistance devices in minimally invasive cochlear implantation

NASA Astrophysics Data System (ADS)

Lexow, G. Jakob; Kluge, Marcel; Majdani, Omid; Lenarz, Thomas; Rau, Thomas S.

2017-03-01

Several research groups have proposed individual solutions for surgical assistance devices to perform minimally invasive cochlear implantation. The main challenge is the drilling of a small bore hole from the surface of the skull to the inner ear at submillimetric accuracy. Each group tested the accuracy of their device in their respective test bench or in a small number of temporal bone specimens. This complicates the comparison of the different approaches. Thus, a simple and inexpensive phantom based evaluation method is proposed which resembles clinical conditions. The method is based on half-skull phantoms made of bone-substitute material - optionally equipped with an artificial skin replica to include skin incision within the evaluation procedure. Anatomical structures of the temporal bone derived from segmentations using clinical imaging data are registered into a computer tomographic scan of the skull phantom and used for the planning of the drill trajectory. Drilling is performed with the respective device under conditions close to the intraoperative setting. Evaluation of accuracy can either be performed through postoperative imaging or by means of added targets on the inside of the skull model. Two different targets are proposed: simple reference marks only for measuring the accuracy of the device and a target containing a scala tympani model for evaluation of the complete workflow including the insertion of the electrode carrier. Experiments using the presented method take place under reproducible conditions thus allowing the comparison of the different approaches. In addition, artificial phantoms are easier to obtain and handle than human specimens.

Force Rendering and its Evaluation of a Friction-Based Walking Sensation Display for a Seated User.

PubMed

Kato, Ginga; Kuroda, Yoshihiro; Kiyokawa, Kiyoshi; Takemura, Haruo

2018-04-01

Most existing locomotion devices that represent the sensation of walking target a user who is actually performing a walking motion. Here, we attempted to represent the walking sensation, especially a kinesthetic sensation and advancing feeling (the sense of moving forward) while the user remains seated. To represent the walking sensation using a relatively simple device, we focused on the force rendering and its evaluation of the longitudinal friction force applied on the sole during walking. Based on the measurement of the friction force applied on the sole during actual walking, we developed a novel friction force display that can present the friction force without the influence of body weight. Using performance evaluation testing, we found that the proposed method can stably and rapidly display friction force. Also, we developed a virtual reality (VR) walk-through system that is able to present the friction force through the proposed device according to the avatar's walking motion in a virtual world. By evaluating the realism, we found that the proposed device can represent a more realistic advancing feeling than vibration feedback.

Ignitability test method

NASA Technical Reports Server (NTRS)

Bement, Laurence J.; Schimmel, Morry L.

1989-01-01

To overcome serious weaknesses in determining the performance of initiating devices, a novel 'ignitability test method', representing actual design interfaces and ignition materials, has been developed. Ignition device output consists of heat, light, gas an burning particles. Past research methods have evaluated these parameters individually. This paper describes the development and demonstration of an ignitability test method combining all these parameters, and the quantitative assessment of the ignition performance of two widely used percussion primers, the M42C1-PA101 and the M42C2-793. The ignition materials used for this evaluation were several powder, granule and pellet sizes of black powder and boron-potassium nitrate. This test method should be useful for performance evaluation of all initiator types, quality assurance, evaluation of ignition interfaces, and service life studies of initiators and ignition materials.

Screening method to evaluate point-of-care human chorionic gonadotropin (hCG) devices for susceptibility to the hook effect by hCG β core fragment: evaluation of 11 devices.

PubMed

Nerenz, Robert D; Song, Haowei; Gronowski, Ann M

2014-04-01

The predominant hCG variant in urine, hCG β core fragment (hCGβcf), has been demonstrated to cause false-negative results in qualitative point-of-care (POC) hCG devices. This is a major concern for healthcare professionals using POC pregnancy tests. We developed a screening method to evaluate qualitative POC hCG devices for their susceptibility to inhibition by hCGβcf. Using this method, we evaluated the performance of 11 commonly used devices. A wide range of purified hCG and hCGβcf concentrations were mixed and tested on 2 POC devices. By use of those results, a screening method was defined and 9 additional POC devices were evaluated. Two solutions containing (a) 500 pmol/L (171 IU/L) intact hCG with 0 pmol/L hCGβcf and (b) 500 pmol/L intact hCG with 500 000 pmol/L hCGβcf were used to screen all POC devices. The OSOM and Cen-Med Elite devices were found to be most susceptible to false-negative results due to hCGβcf. The BC Icon 20 and the Alere were the least susceptible. The remaining 7 were moderately affected. Devices that gave the strongest signal with hCGβcf alone were those that were least likely to show a hook effect. The screening method put forth here can be used by device users and manufacturers to evaluate POC devices for inhibition by hCGβcf. Of 11 devices evaluated, only 2 have been identified that exhibit minimal to no susceptibility to hCGβcf.

A Novel Wireless Wearable Volatile Organic Compound (VOC) Monitoring Device with Disposable Sensors.

PubMed

Deng, Yue; Chen, Cheng; Xian, Xiaojun; Tsow, Francis; Verma, Gaurav; McConnell, Rob; Fruin, Scott; Tao, Nongjian; Forzani, Erica S

2016-12-03

A novel portable wireless volatile organic compound (VOC) monitoring device with disposable sensors is presented. The device is miniaturized, light, easy-to-use, and cost-effective. Different field tests have been carried out to identify the operational, analytical, and functional performance of the device and its sensors. The device was compared to a commercial photo-ionization detector, gas chromatography-mass spectrometry, and carbon monoxide detector. In addition, environmental operational conditions, such as barometric change, temperature change and wind conditions were also tested to evaluate the device performance. The multiple comparisons and tests indicate that the proposed VOC device is adequate to characterize personal exposure in many real-world scenarios and is applicable for personal daily use.

A Novel Wireless Wearable Volatile Organic Compound (VOC) Monitoring Device with Disposable Sensors

PubMed Central

Deng, Yue; Chen, Cheng; Xian, Xiaojun; Tsow, Francis; Verma, Gaurav; McConnell, Rob; Fruin, Scott; Tao, Nongjian; Forzani, Erica S.

2016-01-01

A novel portable wireless volatile organic compound (VOC) monitoring device with disposable sensors is presented. The device is miniaturized, light, easy-to-use, and cost-effective. Different field tests have been carried out to identify the operational, analytical, and functional performance of the device and its sensors. The device was compared to a commercial photo-ionization detector, gas chromatography-mass spectrometry, and carbon monoxide detector. In addition, environmental operational conditions, such as barometric change, temperature change and wind conditions were also tested to evaluate the device performance. The multiple comparisons and tests indicate that the proposed VOC device is adequate to characterize personal exposure in many real-world scenarios and is applicable for personal daily use. PMID:27918484

Evaluating Imaging and Computer-aided Detection and Diagnosis Devices at the FDA

PubMed Central

Gallas, Brandon D.; Chan, Heang-Ping; D’Orsi, Carl J.; Dodd, Lori E.; Giger, Maryellen L.; Gur, David; Krupinski, Elizabeth A.; Metz, Charles E.; Myers, Kyle J.; Obuchowski, Nancy A.; Sahiner, Berkman; Toledano, Alicia Y.; Zuley, Margarita L.

2017-01-01

This report summarizes the Joint FDA-MIPS Workshop on Methods for the Evaluation of Imaging and Computer-Assist Devices. The purpose of the workshop was to gather information on the current state of the science and facilitate consensus development on statistical methods and study designs for the evaluation of imaging devices to support US Food and Drug Administration submissions. Additionally, participants expected to identify gaps in knowledge and unmet needs that should be addressed in future research. This summary is intended to document the topics that were discussed at the meeting and disseminate the lessons that have been learned through past studies of imaging and computer-aided detection and diagnosis device performance. PMID:22306064

Performance Modeling of Network-Attached Storage Device Based Hierarchical Mass Storage Systems

NASA Technical Reports Server (NTRS)

Menasce, Daniel A.; Pentakalos, Odysseas I.

1995-01-01

Network attached storage devices improve I/O performance by separating control and data paths and eliminating host intervention during the data transfer phase. Devices are attached to both a high speed network for data transfer and to a slower network for control messages. Hierarchical mass storage systems use disks to cache the most recently used files and a combination of robotic and manually mounted tapes to store the bulk of the files in the file system. This paper shows how queuing network models can be used to assess the performance of hierarchical mass storage systems that use network attached storage devices as opposed to host attached storage devices. Simulation was used to validate the model. The analytic model presented here can be used, among other things, to evaluate the protocols involved in 1/0 over network attached devices.

Performance evaluation of thin wearing courses through scaled accelerated trafficking.

DOT National Transportation Integrated Search

2014-01-01

The primary objective of this study was to evaluate the permanent deformation (rutting) and fatigue performance of : several thin asphalt concrete wearing courses using a scaled-down accelerated pavement testing device. The accelerated testing : was ...

Performance Evaluation of Thin Wearing Courses Through Scaled Accelerated Trafficking.

DOT National Transportation Integrated Search

2014-01-01

"The primary objective of this study was to evaluate the permanent deformation (rutting) and fatigue performance of : several thin asphalt concrete wearing courses using a scaled-down accelerated pavement testing device. The accelerated testing : was...

A novel portable device to measure the temperature of both the inner and the outer tubes of a parabolic receiver in the field

NASA Astrophysics Data System (ADS)

Hermoso, J. L. Navarro; Espinosa-Rueda, Guillermo; Martinez, Noelia; Heras, Carlos; Osta, Marta

2016-05-01

The performance of parabolic trough (PT) receiver tubes (RT) has a direct impact on Solar Thermal Energy (STE) plant production. As a result, one major need of operation and maintenance (O&M) in STE plants is to monitor the state of the receiver tube as a key element in the solar field. However the lack of specific devices so far has limited the proper evaluation of operating receiver tubés thermal performance. As a consequence non-accurate approximations have been accepted until now using infrared thermal images of the glass outer tube. In order to fulfill this need, Abengoa has developed a unique portable device for evaluating the thermal performance and vacuum state of parabolic trough receiver tubes placed in the field. The novel device described in this paper, simultaneously provides the temperature of both the inner steel tube and the outer glass tube enabling a check on manufacturers specifications. The on-field evaluation of any receiver tube at any operating temperature has become possible thanks to this new measuring device. The features and usability of this new measurement system as a workable portable device in operating solar fields provide a very useful tool for all companies in the sector contributing to technology progress. The originality of the device, patent pending P201431969, is not limited to the CSP sector, also having scientific significance in the general measuring instruments field. This paper presents the work carried out to develop and validate the device, also detailing its functioning properties and including the excellent results obtained in the laboratory to determine its accuracy and standard deviation. This information was validated with data collected by O&M teams using this instrument in a commercial CSP plant. The relevance of the device has been evidenced by evaluating a wide sample of RT and the results are discussed in this paper. Finally, all the on field collected data is used to demonstrate the high impact that using this unique portable device will have on a parabolic trough solar power plant.

Development and performance evaluation of an MR squeeze-mode damper

NASA Astrophysics Data System (ADS)

Sapiński, Bogdan; Gołdasz, Janusz

2015-11-01

In this paper the authors present results of a magnetorheological (MR) damper prototype development and performance evaluation study. The damper is a device functioning in the so-called squeeze-mode of MR fluid flow regime of operation. By principle, in a squeeze-mode damper the control (working) gap height varies according to the prescribed displacement or force input profile. Such hardware has been claimed to be well suited to small-amplitude vibration damping applications. However, it is still in its infancy. Its potential seems appealing yet unclear. Accordingly, the authors reveal performance figures of the damper complemented by numerical finite-element simulations of the electro-magnetic circuit of the device. The numerical results are presented in the form of maps of averaged magnetic flux density versus coil current and gap height as well as magnetic flux, inductance, and cogging force calculations, respectively. The simulated data are followed by experimental evaluation of the damper performance incorporating plots of force versus piston displacement (velocity) across a prescribed range of excitation inputs. Moreover, some insight into transient (unsteady) characteristics of the device is provided through testing results involving transient currents.

INNOVATIVE TECHNOLOGY VERIFICATION REPORT " ...

EPA Pesticide Factsheets

The EnSys Petro Test System developed by Strategic Diagnostics Inc. (SDI), was demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program in June 2000 at the Navy Base Ventura County site in Port Hueneme, California. The purpose of the demonstration was to collect reliable performance and cost data for the EnSys Petro Test System and six other field measurement devices for total petroleum hydrocarbons (TPH) in soil. In addition to assessing ease of device operation, the key objectives of the demonstration included determining the (1) method detection limit, (2) accuracy and precision, (3) effects of interferents and soil moisture content on TPH measurement, (4) sample throughput, and (5) TPH measurement costs for each device. The demonstration involved analysis of both performance evaluation samples and environmental samples collected in four areas contaminated with gasoline, diesel, or other petroleum products. The performance and cost results for a given field measurement device were compared to those for an off-site laboratory reference method,

INNOVATIVE TECHNOLOGY VERIFICATION REPORT " ...

EPA Pesticide Factsheets

The Synchronous Scanning Luminoscope (Luminoscope) developed by the Oak Ridge National Laboratory in collaboration with Environmental Systems Corporation (ESC) was demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program in June 2000 at the Navy Base Ventura County site in Port Hueneme, California. The purpose of the demonstration was to collect reliable performance and cost data for the Luminoscope and six other field measurement devices for total petroleum hydrocarbons (TPH) in soil. In addition to assessing ease of device operation, the key objectives of the demonstration included determining the (1) method detection limit, (2) accuracy and precision, (3) effects of interferents and soil moisture content on TPH measurement, (4) sample throughput, and (5) TPH measurement costs for each device. The demonstration involved analysis of both performance evaluation samples and environmental samples collected in five areas contaminated with gasoline, diesel, lubricating oil, or other petroleum products. The performance and cost results for a given field measurement device were compared to those for an off-site laboratory reference method,

Performance characterization of a rotary centrifugal left ventricular assist device with magnetic suspension.

PubMed

Jahanmir, Said; Hunsberger, Andrew Z; Heshmat, Hooshang; Tomaszewski, Michael J; Walton, James F; Weiss, William J; Lukic, Branka; Pae, William E; Zapanta, Conrad M; Khalapyan, Tigran Z

2008-05-01

The MiTiHeart (MiTiHeart Corporation, Gaithersburg, MD, USA) left ventricular assist device (LVAD), a third-generation blood pump, is being developed for destination therapy for adult heart failure patients of small to medium frame that are not being served by present pulsatile devices. The pump design is based on a novel, patented, hybrid passive/active magnetic bearing system with backup hydrodynamic thrust bearing and exhibits low power loss, low vibration, and low hemolysis. Performance of the titanium alloy prototype was evaluated in a series of in vitro tests with blood analogue to map out the performance envelop of the pump. The LVAD prototype was implanted in a calf animal model, and the in vivo pump performance was evaluated. The animal's native heart imparted a strong pulsatility to the flow rate. These tests confirmed the efficacy of the MiTiHeart LVAD design and confirmed that the pulsatility does not adversely affect the pump performance.

Reading performance with large fonts on high-resolution displays

NASA Astrophysics Data System (ADS)

Powers, Maureen K.; Larimer, James O.; Gille, Jennifer; Liu, Hsien-Chang

2004-06-01

Reading is a fundamental task and skill in many environments including business, education, and the home. Today, reading often occurs on electronic displays in addition to traditional hard copy media such as books and magazines, presenting issues of legibility and other factors that can affect human performance [1]. In fact, the transition to soft copy media for text images is often met with worker complaints about their vision and comfort while reading [2-6]. Careful comparative evaluations of reading performance across hard and soft copy device types are rare, even though they are clearly important given the rapid and substantial improvements in soft copy devices available in the marketplace over the last 5 years. To begin to fill this evaluation gap, we compared reading performance on three different soft copy devices and traditional paper. This study does not investigate comfort factors such as display location, seating comfort, and more general issues of lighting, rather we focus instead on a narrow examination of reading performance differences across display types when font sizes are large.

40 CFR Table 7 to Subpart Vvvv of... - Applicability and Timing of Notifications

Code of Federal Regulations, 2010 CFR

2010-07-01

... § 63.9(e). b. A notification of the date for the continuous monitoring system performance evaluation as... control device performance test and continuous monitoring system performance evaluation. ... Notifications 7 Table 7 to Subpart VVVV of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

Optical-to-optical interface device. [consisting of two transparent electrodes on glass substrates that enclose thin film photoconductor and thin layer of nematic liquid crystal

NASA Technical Reports Server (NTRS)

Jacobson, A. D.

1973-01-01

Studies were conducted on the performance of a photoactivated dc liquid crystal light valve. The dc light valve is a thin film device that consists of two transparent electrodes, deposited on glass substrates, that enclose a thin film photoconductor (cadmium sulfide) and a thin layer of a nematic liquid crystal that operates in the dynamic scattering mode. The work was directed toward application of the light valve to high resolution non-coherent light to coherent light image conversion. The goal of these studies was to improve the performance and quality of the already existing dc light valve device and to evaluate quantitatively the properties and performance of the device as they relate to the coherent optical data processing application. As a result of these efforts, device sensitivity was improved by a factor of ten, device resolution was improved by a factor of three, device lifetime was improved by two-orders of magnitude, undesirable secondary liquid crystal scattering effects were eliminated, the scattering characteristics of the liquid crystal were thoroughly documented, the cosmetic quality of the devices was dramatically improved, and the performance of the device was fully documented.

Interacting with notebook input devices: an analysis of motor performance and users' expertise.

PubMed

Sutter, Christine; Ziefle, Martina

2005-01-01

In the present study the usability of two different types of notebook input devices was examined. The independent variables were input device (touchpad vs. mini-joystick) and user expertise (expert vs. novice state). There were 30 participants, of whom 15 were touchpad experts and the other 15 were mini-joystick experts. The experimental tasks were a point-click task (Experiment 1) and a point-drag-drop task (Experiment 2). Dependent variables were the time and accuracy of cursor control. To assess carryover effects, we had the participants complete both experiments, using not only the input device for which they were experts but also the device for which they were novices. Results showed the touchpad performance to be clearly superior to mini-joystick performance. Overall, experts showed better performance than did novices. The significant interaction of input device and expertise showed that the use of an unknown device is difficult, but only for touchpad experts, who were remarkably slower and less accurate when using a mini-joystick. Actual and potential applications of this research include an evaluation of current notebook input devices. The outcomes allow ergonomic guidelines to be derived for optimized usage and design of the mini-joystick and touchpad devices.

Antiangiogenic activity of a bevacizumab-loaded polyurethane device in animal neovascularization models.

PubMed

Ferreira, A E R; Castro, B F M; Vieira, L C; Cassali, G D; Souza, C M; Fulgêncio, G O; Ayres, E; Oréfice, R L; Jorge, R; Silva-Cunha, A; Fialho, S L

2017-03-01

To evaluate the antiangiogenic activity of bevacizumab-loaded polyurethane using two animal models of neovascularization. The percentage of blood vessels was evaluated in a chicken chorioallantoic membrane model (n=42) and in the rabbit cornea (n=24) with neovascularization induced by alkali injury. In each model, the animals were randomly divided into the groups treated with the bevacizumab-loaded polyurethane device, phosphate-buffered-saline (negative control) and bevacizumab commercial solution (positive control). Clinical examination, as well as histopathological and immunohistochemical evaluation, were performed in the rabbit eyes. Microvascular density in hot spot areas was determined in semi-thin sections of corneal tissue by hematoxylin-eosin staining and factor VIII immunohistochemistry. Immunohistochemical analysis was also performed to evaluate VEGF expression. In the evaluated models, the use of bevacizumab (Avastin ® ) and the bevacizumab-loaded polyurethane device led to similar results with regard to inhibition of neovascularization. In the chorioallantoic membrane model, the bevacizumab-loaded polyurethane device reduced angiogenesis by 50.27% when compared to the negative control group. In the rabbit model of corneal neovascularization, the mean density of vessels/field was reduced by 46.87% on analysis of factor VIII immunohistochemistry photos in the bevacizumab-loaded polyurethane device group as compared to the negative control (PBS) sections. In both models, no significant difference could be identified between the bevacizumab-loaded polyurethane device and the positive control group, leading to similar results with regard to inhibition of neovascularization. The present study shows that the bevacizumab-loaded polyurethane device may release bevacizumab and inhibit neovascularization similarly to commercial bevacizumab solution in the short-term. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Control Board Digital Interface Input Devices – Touchscreen, Trackpad, or Mouse?

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

Thomas A. Ulrich; Ronald L. Boring; Roger Lew

The authors collaborated with a power utility to evaluate input devices for use in the human system interface (HSI) for a new digital Turbine Control System (TCS) at a nuclear power plant (NPP) undergoing a TCS upgrade. A standalone dynamic software simulation of the new digital TCS and a mobile kiosk were developed to conduct an input device study to evaluate operator preference and input device effectiveness. The TCS software presented the anticipated HSI for the TCS and mimicked (i.e., simulated) the turbine systems’ responses to operator commands. Twenty-four licensed operators from the two nuclear power units participated in themore » study. Three input devices were tested: a trackpad, mouse, and touchscreen. The subjective feedback from the survey indicates the operators preferred the touchscreen interface. The operators subjectively rated the touchscreen as the fastest and most comfortable input device given the range of tasks they performed during the study, but also noted a lack of accuracy for selecting small targets. The empirical data suggest the mouse input device provides the most consistent performance for screen navigation and manipulating on screen controls. The trackpad input device was both empirically and subjectively found to be the least effective and least desired input device.« less

The Development of a Quality Management Framework for Evaluating Medical Device Reprocessing Practice in Healthcare Facilities.

PubMed

Lorv, Bailey; Horodyski, Robin; Welton, Cynthia; Vail, John; Simonetto, Luca; Jokanovic, Danilo; Sharma, Richa; Mahoney, Angela Rea; Savoy-Bird, Shay; Bains, Shalu

2017-01-01

There is increasing awareness of the importance of medical device reprocessing (MDR) for the provision of safe patient care. Although industry service standards are available to guide MDR practices, there remains a lack of published key performance indicators (KPIs) and targets that are necessary to evaluate MDR quality for feedback and improvement. This article outlines the development of an initial framework that builds on established guidelines and includes service standards, KPIs and targets for evaluating MDR operations. This framework can support healthcare facilities in strengthening existing practices and enables a platform for collaboration towards better MDR performance management.

Evaluation of Exposure From a Low Energy X-Ray Device Using Thermoluminescent Dosimeters

NASA Technical Reports Server (NTRS)

Edwards, David L.; Harris, William S., Jr.

1997-01-01

The exposure from an electron beam welding device was evaluated using thermoluminescent dosimeters (TLDs). The device generated low energy X-rays which the current dose equivalent conversion algorithm was not designed to evaluate making it necessary to obtain additional information relating to TLD operation at the photon energies encountered with the device. This was accomplished by performing irradiations at the National Institute of Standards and Technology (NIST) using low energy X-ray techniques. The resulting data was used to determine TLD badge response for low energy X-rays and to establish the relationship between TLD element response and the dose equivalent at specific depths in tissue for these photon energies. The new energy/dose equivalent calibration data was used to calculate the shallow and eye dose equivalent of badges exposed to the device.

Effects of ionizing radiation on charge-coupled imagers

NASA Technical Reports Server (NTRS)

Killiany, J. M.; Baker, W. D.; Saks, N. S.; Barbe, D. F.

1975-01-01

The effects of ionizing radiation on three different charge coupled imagers have been investigated. Device performance was evaluated as a function of total gamma ray dose. The principal failure mechanisms have been identified for each particular device structure. The clock and bias voltages required for high total dose operation of the devices are presented.

Development and evaluation of endurance test system for ventricular assist devices.

PubMed

Sumikura, Hirohito; Homma, Akihiko; Ohnuma, Kentaro; Taenaka, Yoshiyuki; Takewa, Yoshiaki; Mukaibayashi, Hiroshi; Katano, Kazuo; Tatsumi, Eisuke

2013-06-01

We developed a novel endurance test system that can arbitrarily set various circulatory conditions and has durability and stability for long-term continuous evaluation of ventricular assist devices (VADs), and we evaluated its fundamental performance and prolonged durability and stability. The circulation circuit of the present endurance test system consisted of a pulsatile pump with a small closed chamber (SCC), a closed chamber, a reservoir and an electromagnetic proportional valve. Two duckbill valves were mounted in the inlet and outlet of the pulsatile pump. The features of the circulation circuit are as follows: (1) the components of the circulation circuit consist of optimized industrial devices, giving durability; (2) the pulsatile pump can change the heart rate and stroke length (SL), as well as its compliance using the SCC. Therefore, the endurance test system can quantitatively reproduce various circulatory conditions. The range of reproducible circulatory conditions in the endurance test circuit was examined in terms of fundamental performance. Additionally, continuous operation for 6 months was performed in order to evaluate the durability and stability. The circulation circuit was able to set up a wide range of pressure and total flow conditions using the SCC and adjusting the pulsatile pump SL. The long-term continuous operation test demonstrated that stable, continuous operation for 6 months was possible without leakage or industrial device failure. The newly developed endurance test system demonstrated a wide range of reproducible circulatory conditions, durability and stability, and is a promising approach for evaluating the basic characteristics of VADs.

Contamination avoidance devices for poppet type shutoff valves

NASA Technical Reports Server (NTRS)

Endicott, D. L.

1972-01-01

The technology required to provide acceptable contamination damage avoidance characteristics for poppet type shutoff valves is discussed. Evaluation of the contamination avoidance characteristics of the basic 1T32095 propellant shutoff valve, the cycle life performance of these valves in an uncontaminated environment, and the effectiveness of various auxiliary contamination avoidance devices when used in conjunction with these poppet type valves are included. In addition, a secondary objective is to evaluate two methods of monitoring the performance of the test valves during actual operations using acoustical monitoring instrumentation.

Self-Consistent Monte Carlo Study of the Coulomb Interaction under Nano-Scale Device Structures

NASA Astrophysics Data System (ADS)

Sano, Nobuyuki

2011-03-01

It has been pointed that the Coulomb interaction between the electrons is expected to be of crucial importance to predict reliable device characteristics. In particular, the device performance is greatly degraded due to the plasmon excitation represented by dynamical potential fluctuations in high-doped source and drain regions by the channel electrons. We employ the self-consistent 3D Monte Carlo (MC) simulations, which could reproduce both the correct mobility under various electron concentrations and the collective plasma waves, to study the physical impact of dynamical potential fluctuations on device performance under the Double-gate MOSFETs. The average force experienced by an electron due to the Coulomb interaction inside the device is evaluated by performing the self-consistent MC simulations and the fixed-potential MC simulations without the Coulomb interaction. Also, the band-tailing associated with the local potential fluctuations in high-doped source region is quantitatively evaluated and it is found that the band-tailing becomes strongly dependent of position in real space even inside the uniform source region. This work was partially supported by Grants-in-Aid for Scientific Research B (No. 2160160) from the Ministry of Education, Culture, Sports, Science and Technology in Japan.

Hazard-Free Pyrotechnic Simulator

NASA Technical Reports Server (NTRS)

Mcalister, William B., Jr.

1988-01-01

Simulator evaluates performance of firing circuits for electroexplosive devices (EED's) safely and inexpensively. Tests circuits realistically when pyrotechnic squibs not connected and eliminates risks of explosions. Used to test such devices as batteries where test conditions might otherwise degrade them.

The Evaluation of Reading Performance with Minnesota Low Vision Reading Charts in Patients with Age-related Macular Degeneration.

PubMed

Altinbay, Deniz; Adibelli, Fatih Mehmet; Taskin, Ibrahim; Tekin, Adil

2016-01-01

To evaluate the reading performance using the Minnesota low vision reading (MNREAD) charts, of patients with age-related macular degeneration (AMD) who use low vision aid (LVA) devices. This prospective study enrolled 27 patients with AMD. Distance visual acuity (VA) was evaluated with a distance chart designed for patients with low vision. Near vision and reading performance were evaluated with the Turkish version of the MNREAD charts. Unaided vision and vision with LVA devices and high spherical add near glasses was measured. P <0.05 was considered statistically significant. The mean unaided near VA was 1.05 ± 0.27 log of the minimum angle of resolution (LogMAR). The mean VA with the LVA devices was 0.71 ± 0.41 LogMAR. Reading acuity ranged between 1.15 and 0.21 LogMAR, critical print size was between - 1.2 and 0.2 LogMAR. Maximum reading speeds were between 0 and 103 words/min. The cases are divided into groups in terms of reading speed according to age, gender, diagnosis, and education. Reading speed was negatively correlated to increasing age. MNREAD reading charts can be used to evaluate reading performance in patients with AMD with low vision. The outcomes of the present study indicate that optical correction is adequate for near VA requirements in this patient population. However, optical correction was inadequate for improving reading performance. Appropriate rehabilitation programs can be used to increase reading speed.

Analytical and Experimental Performance Evaluation of BLE Neighbor Discovery Process Including Non-Idealities of Real Chipsets

PubMed Central

Perez-Diaz de Cerio, David; Hernández, Ángela; Valenzuela, Jose Luis; Valdovinos, Antonio

2017-01-01

The purpose of this paper is to evaluate from a real perspective the performance of Bluetooth Low Energy (BLE) as a technology that enables fast and reliable discovery of a large number of users/devices in a short period of time. The BLE standard specifies a wide range of configurable parameter values that determine the discovery process and need to be set according to the particular application requirements. Many previous works have been addressed to investigate the discovery process through analytical and simulation models, according to the ideal specification of the standard. However, measurements show that additional scanning gaps appear in the scanning process, which reduce the discovery capabilities. These gaps have been identified in all of the analyzed devices and respond to both regular patterns and variable events associated with the decoding process. We have demonstrated that these non-idealities, which are not taken into account in other studies, have a severe impact on the discovery process performance. Extensive performance evaluation for a varying number of devices and feasible parameter combinations has been done by comparing simulations and experimental measurements. This work also includes a simple mathematical model that closely matches both the standard implementation and the different chipset peculiarities for any possible parameter value specified in the standard and for any number of simultaneous advertising devices under scanner coverage. PMID:28273801

Analytical and Experimental Performance Evaluation of BLE Neighbor Discovery Process Including Non-Idealities of Real Chipsets.

PubMed

Perez-Diaz de Cerio, David; Hernández, Ángela; Valenzuela, Jose Luis; Valdovinos, Antonio

2017-03-03

The purpose of this paper is to evaluate from a real perspective the performance of Bluetooth Low Energy (BLE) as a technology that enables fast and reliable discovery of a large number of users/devices in a short period of time. The BLE standard specifies a wide range of configurable parameter values that determine the discovery process and need to be set according to the particular application requirements. Many previous works have been addressed to investigate the discovery process through analytical and simulation models, according to the ideal specification of the standard. However, measurements show that additional scanning gaps appear in the scanning process, which reduce the discovery capabilities. These gaps have been identified in all of the analyzed devices and respond to both regular patterns and variable events associated with the decoding process. We have demonstrated that these non-idealities, which are not taken into account in other studies, have a severe impact on the discovery process performance. Extensive performance evaluation for a varying number of devices and feasible parameter combinations has been done by comparing simulations and experimental measurements. This work also includes a simple mathematical model that closely matches both the standard implementation and the different chipset peculiarities for any possible parameter value specified in the standard and for any number of simultaneous advertising devices under scanner coverage.

Pen Devices for Insulin Self-Administration Compared With Needle and Vial: Systematic Review of the Literature and Meta-Analysis.

PubMed

Lasalvia, Pieralessandro; Barahona-Correa, Julián Esteban; Romero-Alvernia, Diana Marcela; Gil-Tamayo, Sebastián; Castañeda-Cardona, Camilo; Bayona, Juan Gabriel; Triana, Juan José; Laserna, Andrés Felipe; Mejía-Torres, Miguel; Restrepo-Jimenez, Paula; Jimenez-Zapata, Juliana; Rosselli, Diego

2016-07-01

Pen devices offer advantages compared with vial and syringe (VaS). The purpose of this article was to evaluate efficacy of pen devices compared to VaS. A systematic review of literature was performed in 8 different databases. References were independently screened and selected. Primary observational or experimental studies comparing pen devices with VaS for insulin administrations were included. Studies on specific populations were excluded. Risk of bias was evaluated using appropriate tools. Data on glycosylated hemoglobin (HbA1c), hypoglycemia, adherence, persistence, patient preference, and quality of life (QOL) were collected. Meta-analysis was performed when appropriate. Heterogeneity and risk of publication bias were evaluated. Otherwise, descriptive analyses of the available data was done. In all, 10 348 articles were screened. A total of 17 studies were finally selected: 7 experimental and 10 analytical. The populations of the included articles were mainly composed of adults with type 2 diabetes mellitus. Important risk of bias was found in all of the articles, particularly experimental studies. Meta-analyses were performed for HbA1c, hypoglycemia, adherence and persistence. Pen device showed better results in mean HbA1c change, patients with hypoglycemia, adherence and persistence compared to VaS. No difference was observed in number of patients achieving <7% HbA1c. Preference studies showed a tendency favoring pen devices, however nonvalidated tools were used. One QoL study showed improvements in some subscales of SF-36. There is evidence that pen devices offer benefits in clinical and, less clearly, patient-reported outcomes compared to VaS for insulin administration. However, these results should be taken with caution. © 2016 Diabetes Technology Society.

Evaluation of the SeedCounter, A Mobile Application for Grain Phenotyping.

PubMed

Komyshev, Evgenii; Genaev, Mikhail; Afonnikov, Dmitry

2016-01-01

Grain morphometry in cereals is an important step in selecting new high-yielding plants. Manual assessment of parameters such as the number of grains per ear and grain size is laborious. One solution to this problem is image-based analysis that can be performed using a desktop PC. Furthermore, the effectiveness of analysis performed in the field can be improved through the use of mobile devices. In this paper, we propose a method for the automated evaluation of phenotypic parameters of grains using mobile devices running the Android operational system. The experimental results show that this approach is efficient and sufficiently accurate for the large-scale analysis of phenotypic characteristics in wheat grains. Evaluation of our application under six different lighting conditions and three mobile devices demonstrated that the lighting of the paper has significant influence on the accuracy of our method, unlike the smartphone type.

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices...) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550, you...

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2011 CFR

2011-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices...) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550, you...

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2014 CFR

2014-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices... (c) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550...

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2012 CFR

2012-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices... (c) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550...

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2013 CFR

2013-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices... (c) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550...

Teaching Advanced Operation of an iPod-Based Speech-Generating Device to Two Students with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Achmadi, Donna; Kagohara, Debora M.; van der Meer, Larah; O'Reilly, Mark F.; Lancioni, Giulio E.; Sutherland, Dean; Lang, Russell; Marschik, Peter B.; Green, Vanessa A.; Sigafoos, Jeff

2012-01-01

We evaluated a program for teaching two adolescents with autism spectrum disorders (ASD) to perform more advanced operations on an iPod-based speech-generating device (SGD). The effects of the teaching program were evaluated in a multiprobe multiple baseline across participants design that included two intervention phases. The first intervention…

Polymer taper bridge for silicon waveguide to single mode waveguide coupling

NASA Astrophysics Data System (ADS)

Kruse, Kevin; Middlebrook, Christopher T.

2016-03-01

Coupling of optical power from high-density silicon waveguides to silica optical fibers for signal routing can incur high losses and often requires complex end-face preparation/processing. Novel coupling device taper structures are proposed for low coupling loss between silicon photonic waveguides and single mode fibers are proposed and devices are fabricated and measured in terms of performance. Theoretical mode conversion models for waveguide tapers are derived for optimal device structure design and performance. Commercially viable vertical and multi-layer taper designs using polymer waveguide materials are proposed as innovative, cost-efficient, and mass-manufacturable optical coupling devices. The coupling efficiency for both designs is determined to evaluate optimal device dimensions and alignment tolerances with both silicon rib waveguides and silicon nanowire waveguides. Propagation loss as a function of waveguide roughness and metallic loss are determined and correlated to waveguide dimensions to obtain total insertion loss for the proposed taper designs. Multi-layer tapers on gold-sputtered substrates are fabricated through photolithography as proof-of-concept devices and evaluated for device loss optimization. Tapered waveguide coupling loss with Si WGs (2.74 dB) was experimentally measured with high correlation to theoretical results.

Application and use of spinal immobilization devices in zero-gravity flight

NASA Technical Reports Server (NTRS)

Krupa, Debra T.; Gosbee, John; Billica, Roger; Boyce, Joey B.

1991-01-01

A KC-135 parabolic flight was performed for the purpose of evaluation of spinal immobilization techniques in microgravity. The flight followed the standard 40 parabola profile with four NASA/KRUG experimenters involved. One performed as coordinator/recorder, one as test subject, and two as the Crew Medical Officers (CMO). The flight was to evaluate the application of spinal immobilization devices and techniques in microgravity as are performed during initial stabilization or patient transport scenarios. The sequence of detail for examination of the following objectives included: attempted cervical spine immobilization with all free floating, the patient restrained to the floor, various hand positioning techniques; c-collar placement; Kendrick Extrication Device (KED) application with various restraints for patient and CMO; patient immobilization and transport using the KED; patient transported on KED and spine board. Observations for each task are included. Major conclusions and issues are also included.

[Mobile Health: IEEE Standard for Wearable Cuffless Blood Pressure Measuring Devices].

PubMed

Zhou, Xia; Wu, Wenli; Bao, Shudi

2015-07-01

IEEE Std 1708-2014 breaks through the traditional standards of cuff based blood pressure measuring devices and establishes a normative definition of wearable cuffless blood pressure measuring devices and the objective performance evaluation of this kind of devices. This study firstly introduces the background of the new standard. Then, the standard details will be described, and the impact of cuffless blood pressure measuring devices with the new standard on manufacturers and end users will be addressed.

Identification and validation of nebulized aerosol devices for sputum induction

PubMed Central

Davidson, Warren J; Dennis, John; The, Stephanie; Litoski, Belinda; Pieron, Cora; Leigh, Richard

2014-01-01

Induced sputum cell count measurement has proven reliability for evaluating airway inflammation in patients with asthma and other airway diseases. Although the use of nebulizer devices for sputum induction is commonplace, they are generally labelled as single-patient devices by the manufacturer and, therefore, cannot be used for multiple patients in large clinical sputum induction programs due to infect ion-control requirements. Accordingly, this study investigated the aerosol characteristics of alternative devices that could be used in such programs. BACKGROUND: Induced sputum cell counts are a noninvasive and reliable method for evaluating the presence, type and degree of airway inflammation in patients with asthma. Currently, standard nebulizer devices used for sputum induction in multiple patients are labelled as single-patient devices by the manufacturer, which conflicts with infection prevention and control requirements. As such, these devices cannot feasibly be used in a clinical sputum induction program. Therefore, there is a need to identify alternative nebulizer devices that are either disposable or labelled for multi-patient use. OBJECTIVE: To apply validated rigorous, scientific testing methods to identify and validate commercially available nebulizer devices appropriate for use in a clinical sputum induction program. METHODS: Measurement of nebulized aerosol output and size for the selected nebulizer designs followed robust International Organization for Standardization methods. Sputum induction using two of these nebulizers was successfully performed on 10 healthy adult subjects. The cytotechnologist performing sputum cell counts was blinded to the type of nebulizer used. RESULTS: The studied nebulizers had variable aerosol outputs. The AeroNeb Solo (Aerogen, Ireland), Omron NE-U17 (Omron, Japan) and EASYneb II (Flaem Nuova, Italy) systems were found to have similar measurements of aerosol size. There was no significant difference in induced sputum cell results between the AeroNeb Solo and EASYneb II devices. DISCUSSION: There is a need for rigorous, scientific evaluation of nebulizer devices for clinical applications, including sputum induction, for measurement of cell counts. CONCLUSION: The present study was the most comprehensive analysis of different nebulizer devices for sputum induction to measure cell counts, and provides a framework for appropriate evaluation of nebulizer devices for induced sputum testing. PMID:24288700

Analysis of a digital RF memory in a signal-delay application

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

Jelinek, D.A.

1992-03-01

Laboratory simulation of the approach of a radar fuze towards a target is an important factor in our ability to accurately measure the radar's performance. This simulation is achieved, in part, by dynamically delaying and attenuating the radar's transmitted pulse and sending the result back to the radar's receiver. Historically, the device used to perform the dynamic delay has been a limiting factor in the evaluation of a radar's performance and characteristics. A new device has been proposed that appears to have more capability than previous dynamic delay devices. This device is the digital RF memory. This report presents themore » results of an analysis of a digital RF memory used in a signal-delay application. 2 refs.« less

Design and performance study of a DC-DC flyback converter based on wide bandgap power devices for photovoltaic applications

NASA Astrophysics Data System (ADS)

Alharbi, Salah S.; Alharbi, Saleh S.; Al-bayati, Ali M. S.; Matin, Mohammad

2017-08-01

This paper presents a high-performance dc-dc flyback converter design based on wide bandgap (WBG) semiconductor devices for photovoltaic (PV) applications. Two different power devices, a gallium nitride (GaN)-transistor and a silicon (Si)-MOSFET, are implemented individually in the flyback converter to examine their impact on converter performance. The total power loss of the converter with different power devices is analyzed for various switching frequencies. Converter efficiency is evaluated at different switching frequencies, input voltages, and output power levels. The results reveal that the converter with the GaN-transistor has lower total power loss and better efficiency compared to the converter with the conventional Si-MOSFET.

Reliability Testing of NASA Piezocomposite Actuators

NASA Technical Reports Server (NTRS)

Wilkie, W.; High, J.; Bockman, J.

2002-01-01

NASA Langley Research Center has developed a low-cost piezocomposite actuator which has application for controlling vibrations in large inflatable smart space structures, space telescopes, and high performance aircraft. Tests show the NASA piezocomposite device is capable of producing large, directional, in-plane strains on the order of 2000 parts-per-million peak-to-peak, with no reduction in free-strain performance to 100 million electrical cycles. This paper describes methods, measurements, and preliminary results from our reliability evaluation of the device under externally applied mechanical loads and at various operational temperatures. Tests performed to date show no net reductions in actuation amplitude while the device was moderately loaded through 10 million electrical cycles. Tests were performed at both room temperature and at the maximum operational temperature of the epoxy resin system used in manufacture of the device. Initial indications are that actuator reliability is excellent, with no actuator failures or large net reduction in actuator performance.

Human Factors Approach to Comparative Usability of Hospital Manual Defibrillators.

PubMed

Fidler, Richard; Johnson, Meshell

2016-04-01

Equipment-related issues have recently been cited as a significant contributor to the suboptimal outcomes of resuscitation management. A systematic evaluation of the human-device interface was undertaken to evaluate the intuitive nature of three different defibrillators. Devices tested were the Physio-Control LifePak 15, the Zoll R Series Plus, and the Philips MRx. A convenience sample of 73 multidisciplinary health care providers from 5 different hospitals participated in this study. All subjects' performances were evaluated without any training on the devices being studied to assess the intuitiveness of the user interface to perform the functions of delivering an Automated External Defibrillator (AED) shock, a manual defibrillation, pacing to achieve 100% capture, and synchronized cardioversion on a rhythm simulator. Times to deliver an AED shock were fastest with the Zoll, whereas the Philips had the fastest times to deliver a manual defibrillation. Subjects took the least time to attain 100% capture for pacing with the Physio-Control device. No differences in performance times were seen with synchronized cardioversion among the devices. Human factors issues uncovered during this study included a preference for knobs over soft keys and a desire for clarity in control panel design. This study demonstrated no clearly superior defibrillator, as each of the models exhibited strengths in different areas. When asked their defibrillator preference, 67% of subjects chose the Philips. This comparison of user interfaces of defibrillators in simulated situations allows the assessment of usability that can provide manufacturers and educators with feedback about defibrillator implementation for these critical care devices. Published by Elsevier Ireland Ltd.

Development and Evaluation of English Listening Study Materials for Business People Who Use Mobile Devices: A Case Study

ERIC Educational Resources Information Center

Yamada, Masanori; Kitamura, Satoshi; Shimada, Noriko; Utashiro, Takafumi; Shigeta, Katsusuke; Yamaguchi, Etsuji; Harrison, Richard; Yamauchi, Yuhei; Nakahara, Jun

2011-01-01

This study aims to verify the effectiveness of English language materials using mobile devices for business people in terms of the effect on motivation, overall learning performance, and practical performance in real business situations. We compared the use of materials developed from business English for a sales department in a company…

A review of the latest guidelines for NIBP device validation.

PubMed

Alpert, Bruce S; Quinn, David E; Friedman, Bruce A

2013-12-01

The current ISO Standard is accepted as the National Standard in almost every industrialized nation. An overview of the most recently adopted standards is provided. Standards writing groups including the Advancement of Medical Instrumentation Sphygmomanometer Committee and ISO JWG7 are working to expand standardized evaluation methods to include the evaluation of devices intended for use in environments where motion artifact is common. An Association for the Advancement of Medical Instrumentation task group on noninvasive blood pressure measurement in the presence of motion artifact has published a technical information report containing research and standardized methods for the evaluation of blood pressure device performance in the presence of motion artifact.

EVALUATION OF THE ELECTRO-PL AND ELECTROKLEAN DUST COLLECTORS

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

Dennis, R.; Kristal, E.; Silverman, L.

1958-07-21

Results are presented from performance tests on the Electro-PL and Electro-Klean air cleaning devices. Both devices were tested for moderate cleaning of low loadings such as those encountered in the atmospheric dust range. (C.H.)

REMOVAL OF DBCP FROM GROUNDWATER. VOLUME 1. POE/POU TREATMENT DEVICES: INSTITUTIONAL AND JURISDICTIONAL FACTORS

EPA Science Inventory

The results obtained from evaluating ten GAC POE (point-of-entry) devices show that while these GAC units generally function very satisfactorily, their performance can change markedly over short periods of time.

Scheduled Peripheral Component Interconnect Arbiter

NASA Technical Reports Server (NTRS)

Nixon, Scott Alan (Inventor)

2015-01-01

Systems and methods are described for arbitrating access of a communication bus. In one embodiment, a method includes performing steps on one or more processors. The steps include: receiving an access request from a device of the communication bus; evaluating a bus schedule to determine an importance of the device based on the access request; and selectively granting access of the communication bus to the device based on the importance of the device.

Advanced analytical modeling of double-gate Tunnel-FETs - A performance evaluation

NASA Astrophysics Data System (ADS)

Graef, Michael; Hosenfeld, Fabian; Horst, Fabian; Farokhnejad, Atieh; Hain, Franziska; Iñíguez, Benjamín; Kloes, Alexander

2018-03-01

The Tunnel-FET is one of the most promising devices to be the successor of the standard MOSFET due to its alternative current transport mechanism, which allows a smaller subthreshold slope than the physically limited 60 mV/dec of the MOSFET. Recently fabricated devices show smaller slopes already but mostly not over multiple decades of the current transfer characteristics. In this paper the performance limiting effects, occurring during the fabrication process of the device, such as doping profiles and midgap traps are analyzed by physics-based analytical models and their performance limiting abilities are determined. Additionally, performance enhancing possibilities, such as hetero-structures and ambipolarity improvements are introduced and discussed. An extensive double-gate n-Tunnel-FET model is presented, which meets the versatile device requirements and shows a good fit with TCAD simulations and measurement data.

Evaluation of a new automated instrument for pretransfusion testing.

PubMed

Morelati, F; Revelli, N; Maffei, L M; Poretti, M; Santoro, C; Parravicini, A; Rebulla, P; Cole, R; Sirchia, G

1998-10-01

A number of automated devices for pretransfusion testing have recently become available. This study evaluated a fully automated device based on column agglutination technology (AutoVue System, Ortho, Raritan, NJ). Some 6747 tests including forward and reverse ABO group, Rh type and phenotype, antibody screen, autocontrol, and crossmatch were performed on random samples from 1069 blood donors, 2063 patients, and 98 newborns and cord blood. Also tested were samples from 168 immunized patients and 53 donors expressing weak or variant A and D antigens. Test results and technician times required for their performance were compared with those obtained by standard methods (manual column agglutination technology, slide, semiautomatic handler). No erroneous conclusions were found in regard to the 5028 ABO group and Rh type or phenotype determinations carried out with the device. The device rejected 1.53 percent of tests for sample inadequacy. Of the remaining 18 tests with discrepant results found with the device and not confirmed with the standard methods, 6 gave such results because of mixed-field reactions, 10 gave negative results with A2 RBCs in reverse ABO grouping, and 2 gave very weak positive reactions in antibody screening and crossmatching. In the samples from immunized patients, the device missed one weak anti-K, whereas standard methods missed five weak antibodies. In addition, 48, 34, and 31 of the 53 weak or variant antigens were detected by the device, the slide method, and the semiautomated handler, respectively. Technician time with the standard methods was 1.6 to 7 times higher than that with the device. The technical performance of the device compared favorably with that of standard methods, with a number of advantages, including in particular the saving of technician time. Sample inadequacy was the most common cause of discrepancy, which suggests that standardization of sample collection can further improve the performance of the device.

Hologram stability evaluation for Microsoft HoloLens

NASA Astrophysics Data System (ADS)

Vassallo, Reid; Rankin, Adam; Chen, Elvis C. S.; Peters, Terry M.

2017-03-01

Augmented reality (AR) has an increasing presence in the world of image-guided interventions which is amplified by the availability of consumer-grade head-mounted display (HMD) technology. The Microsoft® HoloLensTM optical passthrough device is at the forefront of consumer technology, as it is the first un-tethered head mounted computer (HMC). It shows promise of effectiveness in guiding clinical interventions, however its accuracy and stability must still be evaluated for the clinical environment. We have developed an evaluative protocol for the HoloLensTM using an optical measurement device to digitize the perceived pose of the rendered hologram. This evaluates the ability of the HoloLensTM to maintain the hologram in its intended pose. The stability is measured when actions are performed that may cause a shift in the holograms' pose due to errors in its simultaneous localization and mapping. An emphasis is placed on actions that are more likely to be performed in a clinical setting. This will be used to determine the most applicable use cases for this technology in the future and how to minimize errors when in use. Our results show promise of this device's potential for intraoperative clinical use. Further analysis must be performed to evaluate other potential sources of hologram disruption.

Development of a versatile high-temperature short-time (HTST) pasteurization device for small-scale processing of cell culture medium formulations.

PubMed

Floris, Patrick; Curtin, Sean; Kaisermayer, Christian; Lindeberg, Anna; Bones, Jonathan

2018-07-01

The compatibility of CHO cell culture medium formulations with all stages of the bioprocess must be evaluated through small-scale studies prior to scale-up for commercial manufacturing operations. Here, we describe the development of a bespoke small-scale device for assessing the compatibility of culture media with a widely implemented upstream viral clearance strategy, high-temperature short-time (HTST) treatment. The thermal stability of undefined medium formulations supplemented with soy hydrolysates was evaluated upon variations in critical HTST processing parameters, namely, holding times and temperatures. Prolonged holding times of 43 s at temperatures of 110 °C did not adversely impact medium quality while significant degradation was observed upon treatment at elevated temperatures (200 °C) for shorter time periods (11 s). The performance of the device was benchmarked against a commercially available mini-pilot HTST system upon treatment of identical formulations on both platforms. Processed medium samples were analyzed by untargeted LC-MS/MS for compositional profiling followed by chemometric evaluation, which confirmed the observed degradation effects caused by elevated holding temperatures but revealed comparable performance of our developed device with the commercial mini-pilot setup. The developed device can assist medium optimization activities by reducing volume requirements relative to commercially available mini-pilot instrumentation and by facilitating fast throughput evaluation of heat-induced effects on multiple medium lots.

Radiation-Tolerance Assessment of a Redundant Wireless Device

NASA Astrophysics Data System (ADS)

Huang, Q.; Jiang, J.

2018-01-01

This paper presents a method to evaluate radiation-tolerance without physical tests for a commercial off-the-shelf (COTS)-based monitoring device for high level radiation fields, such as those found in post-accident conditions in a nuclear power plant (NPP). This paper specifically describes the analysis of radiation environment in a severe accident, radiation damages in electronics, and the redundant solution used to prolong the life of the system, as well as the evaluation method for radiation protection and the analysis method of system reliability. As a case study, a wireless monitoring device with redundant and diversified channels is evaluated by using the developed method. The study results and system assessment data show that, under the given radiation condition, performance of the redundant device is more reliable and more robust than those non-redundant devices. The developed redundant wireless monitoring device is therefore able to apply in those conditions (up to 10 M Rad (Si)) during a severe accident in a NPP.

Empty-bladder (hysterographic) view on US for evaluation of intrauterine devices. Work in progress.

PubMed

Carroll, R; Gombergh, R

1987-06-01

Ultrasound scanning of the pelvis with an empty bladder permits a true frontal view of the uterus to be easily obtained. This view is comparable to the en face view seen at hysterography performed with contrast material. Good definition both of the endometrium and the uterine wall makes this the optimal method for the evaluation of an intrauterine contraceptive device.

Formative usability evaluation of a fixed-dose pen-injector platform device

PubMed Central

Lange, Jakob; Nemeth, Tobias

2018-01-01

Background This article for the first time presents a formative usability study of a fixed-dose pen injector platform device used for the subcutaneous delivery of biopharmaceuticals, primarily for self-administration by the patient. The study was conducted with a user population of both naïve and experienced users across a range of ages. The goals of the study were to evaluate whether users could use the devices safely and effectively relying on the instructions for use (IFU) for guidance, as well as to benchmark the device against another similar injector established in the market. Further objectives were to capture any usability issues and obtain participants’ subjective ratings on the properties and performance of both devices. Methods A total of 20 participants in three groups studied the IFU and performed simulated injections into an injection pad. Results All participants were able to use the device successfully. The device was well appreciated by all users with, maximum usability feedback scores reported by 90% or more on handling forces and device feedback, and by 85% or more on fit and grip of the device. The presence of clear audible and visible feedbacks upon successful loading of a dose and completion of injection was seen to be a significant improvement over the benchmark injector. Conclusion The observation that the platform device can be safely and efficiently used by all user groups provides confidence that the device and IFU in their current form will pass future summative testing in specific applications. PMID:29670411

Acoustic-based Technology to Detect Buried Pipes

DOT National Transportation Integrated Search

2011-07-29

The objective of this project is to build a pre-commercial device, improve its performance to detect multiple buried pipes, and evaluate the pre-commercial device at utility sites. In the past, Gas Technology Institute (GTI) and SoniVerse Inc. (SVI) ...

Usability evaluation of intradermal adapters (IDA).

PubMed

Tsals, Izrail

2017-03-27

Intradermal adapter device technology minimizes the complexity of the Mantoux technique, thereby providing predictable, reproducible intradermal (ID) injections and removing the concerns regarding the ease and reliability of Mantoux technique when using conventional needle and syringe. The technology employs a simple device with geometry designed to gently deform the skin surface and the subcutaneous tissue, providing the ideal angle and depth of needle insertion for consistently successful intradermal injections. The results of this development were presented at the First, Second and Third Skin Vaccination Summits in 2011, 2013 and 2015 respectively [1,2,3]. The current publication addresses the performance of intradermal adapters (IDA) evaluated in three preclinical studies. The evaluations were based on the assessment of bleb formation in a skin model, an accepted indicator of ID injection success. All evaluated devices share the same proprietary dermal interface technology. Devices instituting this design are easy to use, require minimal training, and employ conventionally molded parts and cannula. These studies evaluated IDAs of initial design integral with luer lock needles, IDAs for use with conventional syringes, and intradermal adapters for use with auto disable syringes (ADID adapters). The evaluated ID adapters were intended to consistently place the lancet of the needle at a depth of 0.75mm from the skin's surface. This placement depth addresses the variation in the skin thickness at immunization sites for the majority of patients independent of many other variables. Most participants preferred the intradermal adapter method over the traditional Mantoux and identified a need for the adapter at their workplace. Evaluation of IDAs by registered nurses indicated these devices increase success of bleb formation. The use of IDA increased the success of forming blebs by about 30%. Nurses felt the injections were much easier to perform, in particular by novices. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design and control of RUPERT: a device for robotic upper extremity repetitive therapy.

PubMed

Sugar, Thomas G; He, Jiping; Koeneman, Edward J; Koeneman, James B; Herman, Richard; Huang, H; Schultz, Robert S; Herring, D E; Wanberg, J; Balasubramanian, Sivakumar; Swenson, Pete; Ward, Jeffrey A

2007-09-01

The structural design, control system, and integrated biofeedback for a wearable exoskeletal robot for upper extremity stroke rehabilitation are presented. Assisted with clinical evaluation, designers, engineers, and scientists have built a device for robotic assisted upper extremity repetitive therapy (RUPERT). Intense, repetitive physical rehabilitation has been shown to be beneficial overcoming upper extremity deficits, but the therapy is labor intensive and expensive and difficult to evaluate quantitatively and objectively. The RUPERT is developed to provide a low cost, safe and easy-to-use, robotic-device to assist the patient and therapist to achieve more systematic therapy at home or in the clinic. The RUPERT has four actuated degrees-of-freedom driven by compliant and safe pneumatic muscles (PMs) on the shoulder, elbow, and wrist. They are programmed to actuate the device to extend the arm and move the arm in 3-D space. It is very important to note that gravity is not compensated and the daily tasks are practiced in a natural setting. Because the device is wearable and lightweight to increase portability, it can be worn standing or sitting providing therapy tasks that better mimic activities of daily living. The sensors feed back position and force information for quantitative evaluation of task performance. The device can also provide real-time, objective assessment of functional improvement. We have tested the device on stroke survivors performing two critical activities of daily living (ADL): reaching out and self feeding. The future improvement of the device involves increased degrees-of-freedom and interactive control to adapt to a user's physical conditions.

40 CFR Table 13 to Subpart Wwww of... - Applicability and Timing of Notifications

Code of Federal Regulations, 2010 CFR

2010-07-01

... performance evaluation as specified in § 63.9(g) The date of submission of notification of intent to conduct a... days after the completion of the add-on control device performance test and CMS performance evaluation. ... Notifications 13 Table 13 to Subpart WWWW of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

Preclinical assessment of a modified Occlutech left atrial appendage closure device in a canine model.

PubMed

Kim, Jung-Sun; Lee, Seul-Gee; Bong, Sung-Kyung; Park, Se-Il; Hong, Sung-Yu; Shin, Sanghoon; Shim, Chi Young; Hong, Geu-Ru; Choi, Donghoon; Jang, Yangsoo; Park, Jai-Wun

2016-10-15

LAA occlusion has a similar stroke prevention efficacy compared to anticoagulation treatment for non-valvular atrial fibrillation. The objective of this study was to assess the feasibility and safety of a modified Occlutech® left atrial appendage (LAA) closure device in a canine model. The device was implanted in 10 dogs (33±1kg) using fluoroscopy and transesophageal echocardiography (TEE) guidance. The modified Occlutech® LAA occlusion device was compared with the current version, the Watchman device, and the Amplazter cardiac plug (ACP). LAA occlusion and anchoring to the LAA were evaluated. All dogs were assessed using angiography, TEE, and a gross anatomy examination. The 10 LAA occlusion devices were to be implanted into 10 dogs (5 modified Occlutech devices, 3 current version of Occlutech devices, 1 Watchman, and 1 ACP). LAA implantation was not performed in one dog due to transeptal puncture failure. The three current version of Occlutech devices were embolized immediately after implantation, so three modified devices of the same size were implanted securely without embolization. The mean implant size was 20.1±2.0mm. The devices chosen were a mean of 23.3±10.6% larger than the measured landing zone diameters. Post-implant angiography and TEE revealed well-positioned devices without pericardial effusion or impingement on surrounding structures. The results of this acute animal study suggested that a modified Occlutech® LAA occlusion device was feasible and had greater anchoring performance in canines. Additional large clinical studies are needed to evaluate safety and efficacy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Performance Evaluation of the IrisScan2200 Against Four Respirator Masks

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

WRIGHT, LARRY J.; TERRY, PRESTON L.

2002-02-02

The use of biometrics for the identification of individuals is becoming more prevalent in society and in the general government community. As the demand for these devices increases, it becomes necessary for the user community to have the facts needed to determine which device is the most appropriate for any given application. One such application is the use of biometric devices in areas where an individual may not be able to present a biometric feature that requires contact with the identifier (e.g., when dressed in anti-contamination suits or when wearing a respirator). This paper discusses a performance evaluation conducted onmore » the IrisScan2200 from Iridian Technologies to determine if it could be used in such a role.« less

Pilot Investigation into the Use of an Anthropomorphic Breast Sonography Phantom as a Training and Assessment Tool.

PubMed

Browne, Jacinta E; Cannon, Louise M; McDermott, Ronan; Ryan, Max; Fagan, Andrew J

2017-11-01

A device for the training and quantitative assessment of the competency of trainee radiologists in the technically challenging area of breast sonography was developed and evaluated. Currently, suitable commercially available devices are lacking, and there is a growing realization that the reliance on direct exposure to patients for learning may not represent best practice from either the trainees' or patients' perspective. Three devices (PI, PII and PIII) were designed to produce very realistic sonographic images of breast morphology with a range of embedded pathologies. The pilot evaluation used a case study research design to evaluate the role of the anthropomorphic breast sonography training device in training and assessment in a clinical environment. Through the case study, it was possible to evaluate the process and relationships when using this type of training intervention for a small group of radiology resident trainees. The investigation involved a baseline assessment of trainees' (n = 4) ability to detect and characterize all lesions in PI, followed by a 4-wk training period on PII and a post-training assessment using PIII. The evaluation revealed an improvement of 30% ± 8% in the trainee's performance from pre- to post-training. It was expected that the performance of the trainees would improve as the training phantom described in this study aligns with the learning theory of constructivism and fits the ideal specifications of a medical training device in terms of its realism and facilitation of self-directed learning and deliberate practice of the trainees. The device provides a useful platform upon which training and assessment can be facilitated. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Test and evaluation of constant-flow devices for use in SSN AFFF proportioning systems. Interim report, January-May 1986

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

Williams, F.W.; Back, G.G.; Burns, R.E.

1986-11-04

Constant flow devices, which deliver a constant flow of liquid over a range of upstream and downstream pressures, have been suggested as an alternative to orifice plates for proportioning AFFF in SSN 21 fire-suppression systems. Operational and performance characteristics of two lightweight, inexpensive, commercially available constant-flow devices have significant advantages over orifice plates. Both models tested, however, showed performance degradation when subjected to simulated service conditions. A constant flow device with improved resistance to wear and to AFFF exposure is desirable. Since the constant-flow control devices tested improves proportioning efficiency but do not have optimum characteristics, investigation of improved devicesmore » or methods is recommended.« less

A Novel Device for Grasping Assessment during Functional Tasks: Preliminary Results

PubMed Central

Rocha, Ana Carolinne Portela; Tudella, Eloisa; Pedro, Leonardo M.; Appel, Viviane Cristina Roma; da Silva, Louise Gracelli Pereira; Caurin, Glauco Augusto de Paula

2016-01-01

This paper presents a methodology and first results obtained in a study with a novel device that allows the analysis of grasping quality. Such a device is able to acquire motion information of upper limbs allowing kinetic of manipulation analysis as well. A pilot experiment was carried out with six groups of typically developing children aged between 5 and 10 years, with seven to eight children in each one. The device, designed to emulate a glass, has an optical system composed by one digital camera and a special convex mirror that together allow image acquisition of grasping hand posture when it is grasped and manipulated. It also carries an Inertial Measurement Unit that captures motion data as acceleration, orientation, and angular velocities. The novel instrumented object is used in our approach to evaluate functional tasks performance in quantitative terms. During tests, each child was invited to grasp the cylindrical part of the device that was placed on the top of a table, simulating the task of drinking a glass of water. In the sequence, the child was oriented to transport the device back to the starting position and release it. The task was repeated three times for each child. A grasping hand posture evaluation is presented as an example to evaluate grasping quality. Additionally, motion patterns obtained with the trials performed with the different groups are presented and discussed. This device is attractive due to its portable characteristics, the small size, and its ability to evaluate grasping form. The results may be also useful to analyze the evolution of the rehabilitation process through reach-to-grasping movement and the grasping images analysis. PMID:26942178

An acoustic charge transport imager for high definition television applications

NASA Technical Reports Server (NTRS)

Hunt, William D.; Brennan, Kevin F.; Summers, Christopher J.

1993-01-01

This report covers: (1) invention of a new, ultra-low noise, low operating voltage APD which is expected to offer far better performance than the existing volume doped APD device; (2) performance of a comprehensive series of experiments on the acoustic and piezoelectric properties of ZnO films sputtered on GaAs which can possibly lead to a decrease in the required rf drive power for ACT devices by 15dB; (3) development of an advanced, hydrodynamic, macroscopic simulator used for evaluating the performance of ACT and CTD devices and aiding in the development of the next generation of devices; (4) experimental development of CTD devices which utilize a p-doped top barrier demonstrating charge storage capacity and low leakage currents; (5) refinements in materials growth techniques and in situ controls to lower surface defect densities to record levels as well as increase material uniformity and quality.

Evaluation of light intensity output of QTH and LED curing devices in various governmental health institutions.

PubMed

Al Shaafi, Mm; Maawadh, Am; Al Qahtani, Mq

2011-01-01

The purpose of this study was to evaluate the light intensity output of quartz-tungsten-halogen (QTH) and light emitting diode (LED) curing devices located at governmental health institutions in Riyadh, Saudi Arabia.Eight governmental institutions were involved in the study. The total number of evaluated curing devices was 210 (120 were QTH and 90 were LED). The reading of the light intensity output for each curing unit was achieved using a digital spectrometer; (Model USB4000 Spectrometer, Ocean Optics Inc, Dunedin, FL, USA). The reading procedure was performed by a single investigator; any recording of light intensity below 300 mW/cm2 was considered unsatisfactory.The result found that the recorded mean values of light intensity output for QTH and LED devices were 260 mW/cm2 and 598 mW/cm2, respectively. The percentage of QTH devices and LED devices considered unsatisfactory was 67.5% and 15.6%, respectively. Overall, the regular assessment of light curing devices using light meters is recommended to assure adequate output for clinical use.

Analysis of a digital RF memory in a signal-delay application

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

Jelinek, D.A.

1992-03-01

Laboratory simulation of the approach of a radar fuze towards a target is an important factor in our ability to accurately measure the radar`s performance. This simulation is achieved, in part, by dynamically delaying and attenuating the radar`s transmitted pulse and sending the result back to the radar`s receiver. Historically, the device used to perform the dynamic delay has been a limiting factor in the evaluation of a radar`s performance and characteristics. A new device has been proposed that appears to have more capability than previous dynamic delay devices. This device is the digital RF memory. This report presents themore » results of an analysis of a digital RF memory used in a signal-delay application. 2 refs.« less

Silicon Carbide Diodes Performance Characterization and Comparison With Silicon Devices

NASA Technical Reports Server (NTRS)

Lebron-Velilla, Ramon C.; Schwarze, Gene E.; Trapp, Scott

2003-01-01

Commercially available silicon carbide (SiC) Schottky diodes from different manufacturers were electrically tested and characterized at room temperature. Performed electrical tests include steady state forward and reverse I-V curves, as well as switching transient tests performed with the diodes operating in a hard switch dc-to-dc buck converter. The same tests were performed in current state of the art silicon (Si) and gallium arsenide (GaAs) Schottky and pn junction devices for evaluation and comparison purposes. The SiC devices tested have a voltage rating of 200, 300, and 600 V. The comparison parameters are forward voltage drop at rated current, reverse current at rated voltage and peak reverse recovery currents in the dc to dc converter. Test results show that steady state characteristics of the tested SiC devices are not superior to the best available Si Schottky and ultra fast pn junction devices. Transient tests reveal that the tested SiC Schottky devices exhibit superior transient behavior. This is more evident at the 300 and 600 V rating where SiC Schottky devices showed drastically lower reverse recovery currents than Si ultra fast pn diodes of similar rating.

Performance analysis of InGaAs/GaAsP heterojunction double gate tunnel field effect transistor

NASA Astrophysics Data System (ADS)

Ahish, S.; Sharma, Dheeraj; Vasantha, M. H.; Kumar, Y. B. N.

2017-03-01

In this paper, analog/RF performance of InGaAs/GaAsP heterojunction double gate tunnel field effect transistor (HJTFET) has been explored. A highly doped n+ layer is placed at the Source-Channel junction in order to improve the horizontal electric field component and thus, improve the realiability of the device. The analog performance of the device is analysed by extracting current-voltage characteristics, transcondutance (gm), gate-to-drain capacitance (Cgd) and gate-to-source capacitance (Cgs). Further, RF performance of the device is evaluated by obtaining cut-off frequency (fT) and Gain Bandwidth (GBW) product. ION /IOFF ratio equal to ≈ 109, subthreshold slope of 27 mV/dec, maximum fT of 2.1 THz and maximum GBW of 484 GHz were achieved. Also, the impact of temperature variation on the linearity performance of the device has been investigated. Furthermore, the circuit level performance of the device is performed by implementing a Common Source (CS) amplifier; maximum gain of 31.11 dB and 3-dB cut-off frequency equal to 91.2 GHz were achieved for load resistance (RL) = 17.5 KΩ.

An evaluation of patient self-testing competency of prothrombin time for managing anticoagulation: pre-randomization results of VA Cooperative Study #481--The Home INR Study (THINRS).

PubMed

Dolor, Rowena J; Ruybalid, R Lynne; Uyeda, Lauren; Edson, Robert G; Phibbs, Ciaran; Vertrees, Julia E; Shih, Mei-Chiung; Jacobson, Alan K; Matchar, David B

2010-10-01

Prior studies suggest patient self-testing (PST) of prothrombin time (PT) can improve the quality of anticoagulation (AC) and reduce complications (e.g., bleeding and thromboembolic events). "The Home INR Study" (THINRS) compared AC management with frequent PST using a home monitoring device to high-quality AC management (HQACM) with clinic-based monitoring on major health outcomes. A key clinical and policy question is whether and which patients can successfully use such devices. We report the results of Part 1 of THINRS in which patients and caregivers were evaluated for their ability to perform PST. Study-eligible patients (n = 3643) were trained to use the home monitoring device and evaluated after 2-4 weeks for PST competency. Information about demographics, medical history, warfarin use, medications, plus measures of numeracy, literacy, cognition, dexterity, and satisfaction with AC were collected. Approximately 80% (2931 of 3643) of patients trained on PST demonstrated competency; of these, 8% (238) required caregiver assistance. Testers who were not competent to perform PST had higher numbers of practice attempts, higher cuvette wastage, and were less able to perform a fingerstick or obtain blood for the cuvette in a timely fashion. Factors associated with failure to pass PST training included increased age, previous stroke history, poor cognition, and poor manual dexterity. A majority of patients were able to perform PST. Successful home monitoring of PT with a PST device required adequate levels of cognition and manual dexterity. Training a caregiver modestly increased the proportion of patients who can perform PST.

A Trade Study and Metric for Penetration and Sampling Devices for Possible Use on the NASA 2003 and 2005 Mars Sample Return Missions

NASA Technical Reports Server (NTRS)

McConnell, Joshua B.

2000-01-01

The scientific exploration of Mars will require the collection and return of subterranean samples to Earth for examination. This necessitates the use of some type of device or devices that possesses the ability to effectively penetrate the Martian surface, collect suitable samples and return them to the surface in a manner consistent with imposed scientific constraints. The first opportunity for such a device will occur on the 2003 and 2005 Mars Sample Return missions, being performed by NASA. This paper reviews the work completed on the compilation of a database containing viable penetrating and sampling devices, the performance of a system level trade study comparing selected devices to a set of prescribed parameters and the employment of a metric for the evaluation and ranking of the traded penetration and sampling devices, with respect to possible usage on the 03 and 05 sample return missions. The trade study performed is based on a select set of scientific, engineering, programmatic and socio-political criterion. The use of a metric for the various penetration and sampling devices will act to expedite current and future device selection.

Analysis of dynamical response of air blast loaded safety device

NASA Astrophysics Data System (ADS)

Tropkin, S. N.; Tlyasheva, R. R.; Bayazitov, M. I.; Kuzeev, I. R.

2018-03-01

Equipment of many oil and gas processing plants in the Russian Federation is considerably worn-out. This causes the decrease of reliability and durability of equipment and rises the accident rate. An air explosion is the one of the most dangerous cases for plants in oil and gas industry, usually caused by uncontrolled emission and inflammation of oil products. Air explosion can lead to significant danger for life and health of plant staff, so it necessitates safety device usage. A new type of a safety device is designed. Numerical simulation is necessary to analyse design parameters and performance of the safety device, subjected to air blast loading. Coupled fluid-structure interaction analysis is performed to determine strength of the protective device and its performance. The coupled Euler-Lagrange method, allowable in Abaqus by SIMULIA, is selected as the most appropriate analysis tool to study blast wave interaction with the safety device. Absorption factors of blast wave are evaluated for the safety device. This factors allow one to assess efficiency of the safety device, and its main structural component – dampener. Usage of CEL allowed one to model fast and accurately the dampener behaviour, and to develop the parametric model to determine safety device sizes.

Advanced biosensing methodologies developed for evaluating performance quality and safety of emerging biophotonics technologies and medical devices (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ilev, Ilko K.; Walker, Bennett; Calhoun, William; Hassan, Moinuddin

2016-03-01

Biophotonics is an emerging field in modern biomedical technology that has opened up new horizons for transfer of state-of-the-art techniques from the areas of lasers, fiber optics and biomedical optics to the life sciences and medicine. This field continues to vastly expand with advanced developments across the entire spectrum of biomedical applications ranging from fundamental "bench" laboratory studies to clinical patient "bedside" diagnostics and therapeutics. However, in order to translate these technologies to clinical device applications, the scientific and industrial community, and FDA are facing the requirement for a thorough evaluation and review of laser radiation safety and efficacy concerns. In many cases, however, the review process is complicated due the lack of effective means and standard test methods to precisely analyze safety and effectiveness of some of the newly developed biophotonics techniques and devices. There is, therefore, an immediate public health need for new test protocols, guidance documents and standard test methods to precisely evaluate fundamental characteristics, performance quality and safety of these technologies and devices. Here, we will overview our recent developments of novel test methodologies for safety and efficacy evaluation of some emerging biophotonics technologies and medical devices. These methodologies are based on integrating the advanced features of state-of-the-art optical sensor technologies and approaches such as high-resolution fiber-optic sensing, confocal and optical coherence tomography imaging, and infrared spectroscopy. The presentation will also illustrate some methodologies developed and implemented for testing intraocular lens implants, biochemical contaminations of medical devices, ultrahigh-resolution nanoscopy, and femtosecond laser therapeutics.

Performance evaluation : balloon-type breath alcohol self tester for personal use

DOT National Transportation Integrated Search

1984-01-01

The accuracy of the only breath alcohol balloon-type self test device being marketed for personal use (Luckey Laboratories DM-2) was assessed in the laboratory. Data regarding this self-test device's ability to accurately classify an individual as ha...

Environmental considerations for application of high Tc superconductors in space

NASA Technical Reports Server (NTRS)

Carlberg, I. A.; Kelliher, W. C.; Wise, S. A.; Hooker, M. W.; Buckley, J. D.

1993-01-01

The impact of the environmental factors on the performance of the superconductive devices during spaceflight missions is reviewed. Specific factors typical of spaceflight are addressed to evaluate superconductive devices for space-based applications including preflight storage, radiation, vibration, and thermal cycling.

Noninvasive metabolic profiling using microfluidics for analysis of single preimplantation embryos.

PubMed

Urbanski, John Paul; Johnson, Mark T; Craig, David D; Potter, David L; Gardner, David K; Thorsen, Todd

2008-09-01

Noninvasive analysis of metabolism at the single cell level will have many applications in evaluating cellular physiology. One clinically relevant application would be to determine the metabolic activities of embryos produced through assisted reproduction. There is increasing evidence that embryos with greater developmental capacity have distinct metabolic profiles. One of the standard techniques for evaluating embryonic metabolism has been to evaluate consumption and production of several key energetic substrates (glucose, pyruvate, and lactate) using microfluorometric enzymatic assays. These assays are performed manually using constriction pipets, which greatly limits the utility of this system. Through multilayer soft-lithography, we have designed a microfluidic device that can perform these assays in an automated fashion. Following manual loading of samples and enzyme cocktail reagents, this system performs sample and enzyme cocktail aliquotting, mixing of reagents, data acquisition, and data analysis without operator intervention. Optimization of design and operating regimens has resulted in the ability to perform serial measurements of glucose, pyruvate, and lactate in triplicate with submicroliter sample volumes within 5 min. The current architecture allows for automated analysis of 10 samples and intermittent calibration over a 3 h period. Standard curves generated for each metabolite have correlation coefficients that routinely exceed 0.99. With the use of a standard epifluorescent microscope and CCD camera, linearity is obtained with metabolite concentrations in the low micromolar range (low femtomoles of total analyte). This system is inherently flexible, being easily adapted for any NAD(P)H-based assay and scaled up in terms of sample ports. Open source JAVA-based software allows for simple alterations in routine algorithms. Furthermore, this device can be used as a standalone device in which media samples are loaded or be integrated into microfluidic culture systems for in line, real time metabolic evaluation. With the improved throughput and flexibility of this system, many barriers to evaluating metabolism of embryos and single cells are eliminated. As a proof of principle, metabolic activities of single murine embryos were evaluated using this device.

Performance evaluation of electro-optic effect based graphene transistors

NASA Astrophysics Data System (ADS)

Gupta, Gaurav; Abdul Jalil, Mansoor Bin; Yu, Bin; Liang, Gengchiau

2012-09-01

Despite the advantages afforded by the unique electronic properties of graphene, the absence of a bandgap has limited its applicability in logic devices. This has led to a study on electro-optic behavior in graphene for novel device operations, beyond the conventional field effect, to meet the requirements of ultra-low power and high-speed logic transistors. Recently, two potential designs have been proposed to leverage on this effect and open a virtual bandgap for ballistic transport in the graphene channel. The first one implements a barrier in the centre of the channel, whereas the second incorporates a tilted gate junction. In this paper, we computationally evaluate the relative device performance of these two designs, in terms of subthreshold slope (SS) and ION/IOFF ratio under different temperature and voltage bias, for a defect-free graphene channel. Our calculations employ pure optical modeling for low field electron transport under the constraints of device anatomy. The calculated results show that the two designs are functionally similar and are able to provide SS smaller than 60 mV per decade. Both designs show similar device performance but marginally top one another under different operating constraints. Our results could serve as a guide to circuit designers in selecting an appropriate design as per their system specifications and requirements.

Performance evaluation of electro-optic effect based graphene transistors.

PubMed

Gupta, Gaurav; Jalil, Mansoor Bin Abdul; Yu, Bin; Liang, Gengchiau

2012-10-21

Despite the advantages afforded by the unique electronic properties of graphene, the absence of a bandgap has limited its applicability in logic devices. This has led to a study on electro-optic behavior in graphene for novel device operations, beyond the conventional field effect, to meet the requirements of ultra-low power and high-speed logic transistors. Recently, two potential designs have been proposed to leverage on this effect and open a virtual bandgap for ballistic transport in the graphene channel. The first one implements a barrier in the centre of the channel, whereas the second incorporates a tilted gate junction. In this paper, we computationally evaluate the relative device performance of these two designs, in terms of subthreshold slope (SS) and I(ON)/I(OFF) ratio under different temperature and voltage bias, for a defect-free graphene channel. Our calculations employ pure optical modeling for low field electron transport under the constraints of device anatomy. The calculated results show that the two designs are functionally similar and are able to provide SS smaller than 60 mV per decade. Both designs show similar device performance but marginally top one another under different operating constraints. Our results could serve as a guide to circuit designers in selecting an appropriate design as per their system specifications and requirements.

Using an Elastic Band Device After a Severe Obstetric Pubic Symphyseal Separation: Clinical and Imaging Evaluation.

PubMed

Lasbleiz, Jeremy; Sevestre, François-Xavier; Moquet, Pierre-Yves

2017-09-01

Severe separation of the pubic symphysis is a rare delivery complication. Facing this pathology, we decided to study a new elastic band device. To evaluate the elastic band device, clinical (pain-rated) and imaging (magnetic resonance imaging and radiography) evaluations with and without the device were performed. The elastic band device is a European Conformity-certified medical device, which is made of neoprene straps, that reduces the mobility of the pelvis and the use of the internal rotator muscles. Once the elastic band device was in place, on postpartum day 1, radiography showed a decrease of the pubic width from 41 to 12 mm. Furthermore, pain decreased from 10 of 10 to 2 of 10 in 2 days, allowing the patient to ambulate and avoid surgery. After 1 month, the pubic width (6 mm) and anatomy were recovered but minor pain was still present with hip rotatory movements. The elastic band device was worn 24 hours a day from postpartum days 1-90 and 12 hours a day from postpartum days 90 to 150; afterward, the patient returned to normal life without the elastic band device. Use of an elastic band device was associated with a reduction of the pubic width and pain associated after obstetric pubic symphysis separation.

Pruning a decision tree for selecting computer-related assistive devices for people with disabilities.

PubMed

Chi, Chia-Fen; Tseng, Li-Kai; Jang, Yuh

2012-07-01

Many disabled individuals lack extensive knowledge about assistive technology, which could help them use computers. In 1997, Denis Anson developed a decision tree of 49 evaluative questions designed to evaluate the functional capabilities of the disabled user and choose an appropriate combination of assistive devices, from a selection of 26, that enable the individual to use a computer. In general, occupational therapists guide the disabled users through this process. They often have to go over repetitive questions in order to find an appropriate device. A disabled user may require an alphanumeric entry device, a pointing device, an output device, a performance enhancement device, or some combination of these. Therefore, the current research eliminates redundant questions and divides Anson's decision tree into multiple independent subtrees to meet the actual demand of computer users with disabilities. The modified decision tree was tested by six disabled users to prove it can determine a complete set of assistive devices with a smaller number of evaluative questions. The means to insert new categories of computer-related assistive devices was included to ensure the decision tree can be expanded and updated. The current decision tree can help the disabled users and assistive technology practitioners to find appropriate computer-related assistive devices that meet with clients' individual needs in an efficient manner.

Testing of state roadside safety systems. Volume XI, Appendix J -- Crash testing and evaluation of existing guardrail systems

DOT National Transportation Integrated Search

1999-04-01

The purpose of this study is to crash test and evaluate new or modified roadside safety hardware and, where necessary, redesign the devices to improve their impact performance. The three major areas addressed in this study are the impact performance ...

Development of a reversible vas deferens occlusive device. VI. Long-term evaluation of flexible prosthetic devices.

PubMed

Brueschke, E E; Zaneveld, L J; Kaleckas, R A; Wingfield, J R

1979-05-01

Fifty-three dogs received implants of several types of flexible devices containing valving mechanisms. These devices were constructed entirely of silicone rubber with the exception of the valve stem, which was made of stainless steel. Generally, the devices were (1) implanted in the open mode and left this way for 27 to 44 months, (2) implanted in the closed mode and kept this way for 11 to 12 months before the valves were reopened, (3) implanted in either the closed or open mode and cycled to the opposite mode every 3 months (four or five cycles), or (4) implanted in either the closed or open mode and cycled to the opposite mode every 6 months (two or three cycles). Different implant methods were also evaluated. Semen analyses were regularly performed on all of the dogs, and a number of the animals were bred during the experiments. It can be concluded that (1) the devices can be opened and closed successfully over long periods, respectively allowing and preventing sperm transport; (2) the breeding ability of the animals is not impaired while the devices are in the open mode, independent of the type of device; (3) the devices do not result in an enhanced incidence of congenital abnormalities in the offspring; and (4) the success rate of device performance does not depend on the method of implanatation used. Thus, the results clearly indicate that the basic mechanism of a soft, reversible valve is a feasible approach to conception control.

Evaluation of a new simple collection device for sampling of microparticles in exhaled breath.

PubMed

Seferaj, Sabina; Ullah, Shahid; Tinglev, Åsa; Carlsson, Sten; Winberg, Jesper; Stambeck, Peter; Beck, Olof

2018-03-12

The microparticle fraction of exhaled breath is of interest for developing clinical biomarkers. Exhaled particles may contain non-volatile components from all parts of the airway system, formed during normal breathing. This study aimed to evaluate a new, simple sampling device, based on impaction, for collecting microparticles from exhaled breath. Performance of the new device was compared with that of the existing SensAbues membrane filter device. The analytical work used liquid chromatography-tandem mass spectrometry methods. The new device collected three subsamples and these were separately analysed from eight individuals. No difference was observed between the centre position (0.91 ng/sample) and the side positions (1.01 ng/sample) using major phosphatidylcholine (PC) 16:0/16:0 as the analyte. Exhaled breath was collected from eight patients on methadone maintenance treatment. The intra-individual variability in measured methadone concentration between the three collectors was 8.7%. In another experiment using patients on methadone maintenance treatment, the sampling efficiency was compared with an established filter device. Compared to the existing device, the efficiency of the new device was 121% greater for methadone and 1450% greater for DPPC. The data from lipid analysis also indicated that a larger fraction of the collected material was from the distal parts. Finally, a study using an optical particle counter indicated that the device preferentially collects the larger particle fraction. In conclusion, this study demonstrates the usefulness of the new device for collecting non-volatile components from exhaled breath. The performance of the device was superior to the filter device in several aspects.

Performance evaluation and comparison of three-terminal energy selective electron devices with different connective ways and filter configurations

NASA Astrophysics Data System (ADS)

Peng, Wanli; Zhang, Yanchao; Yang, Zhimin; Chen, Jincan

2018-02-01

Three-terminal energy selective electron (ESE) devices consisting of three electronic reservoirs connected by two energy filters and an electronic conductor with negligible resistance may work as ESE refrigerators and amplifiers. They have three possible connective ways for the electronic conductor and six electronic transmission forms. The configuration of energy filters may be described by the different transmission functions such as the rectangular and Lorentz transmission functions. The ESE devices with three connective ways can be, respectively, regarded as three equivalent hybrid systems composed of an ESE heat engine and an ESE refrigerator/heat pump. With the help of the theory of the ESE devices operated between two electronic reservoirs, the coefficients of performance and cooling rates (heat-pumping rates) of hybrid systems are directly derived. The general performance characteristics of hybrid systems are revealed. The optimal regions of these devices are determined. The performances of the devices with three connective ways of the electronic conductor and two configurations of energy filters are compared in detail. The advantages and disadvantages of each of three-terminal ESE devices are expounded. The results obtained here may provide some guidance for the optimal design and operation of three-terminal ESE devices.

Notebook input devices put to the age test: the usability of trackpoint and touchpad for middle-aged adults.

PubMed

Armbrüster, C; Sutter, C; Ziefle, M

2007-03-01

In two experiments, the usability of input devices integrated into computer notebooks was under study. The most common input devices, touchpad (experiment 1) and trackpoint (experiment 2) were examined. So far, the evaluation of mobile input devices has been restricted to younger users. However, due to ongoing demographic change, the main target group of mobile devices will be older users. Therefore, the present study focused on ageing effects. A total of 14 middle-aged (40-65 years) and 20 younger (20-32 years) users were compared regarding speed and accuracy of cursor control in a point-click and a point-drag-drop task. Moreover, the effects of training were addressed by examining the performance increase over time. In total, 640 trials per task and input device were executed. The results show that ageing is a central factor to be considered in input device design. Middle-aged users were significantly slower than younger users when executing the different tasks. Over time, a significant training effect was observed for both devices and both age groups, although the benefit of training was greater for the middle-aged group. Generally, the touchpad performance was higher than the trackpoint performance in both age groups, but the age-related performance decrements were less distinct when using the touchpad.

Evaluation of a Personal Digital Assistant as a Self-Prompting Device for Increasing Multi-Step Task Completion by Students with Moderate Intellectual Disabilities

ERIC Educational Resources Information Center

Mechling, Linda C.; Gast, David L.; Seid, Nicole H.

2010-01-01

The purpose of this study was to evaluate whether the use of a personal digital assistant (PDA), with picture, auditory, and video prompts, would serve as a portable self-prompting device to facilitate independent task performance by high school age students with moderate intellectual disabilities. A multiple probe design was used across three…

Human breath metabolomics using an optimized noninvasive exhaled breath condensate sampler

PubMed Central

Zamuruyev, Konstantin O.; Aksenov, Alexander A.; Pasamontes, Alberto; Brown, Joshua F.; Pettit, Dayna R.; Foutouhi, Soraya; Weimer, Bart C.; Schivo, Michael; Kenyon, Nicholas J.; Delplanque, Jean-Pierre; Davis, Cristina E.

2017-01-01

Exhaled breath condensate (EBC) analysis is a developing field with tremendous promise to advance personalized, non-invasive health diagnostics as new analytical instrumentation platforms and detection methods are developed. Multiple commercially-available and researcher-built experimental samplers are reported in the literature. However, there is very limited information available to determine an effective breath sampling approach, especially regarding the dependence of breath sample metabolomic content on the collection device design and sampling methodology. This lack of an optimal standard procedure results in a range of reported results that are sometimes contradictory. Here, we present a design of a portable human EBC sampler optimized for collection and preservation of the rich metabolomic content of breath. The performance of the engineered device is compared to two commercially available breath collection devices: the RTube™ and TurboDECCS. A number of design and performance parameters are considered, including: condenser temperature stability during sampling, collection efficiency, condenser material choice, and saliva contamination in the collected breath samples. The significance of the biological content of breath samples, collected with each device, is evaluated with a set of mass spectrometry methods and was the primary factor for evaluating device performance. The design includes an adjustable mass-size threshold for aerodynamic filtering of saliva droplets from the breath flow. Engineering an inexpensive device that allows efficient collection of metalomic-rich breath samples is intended to aid further advancement in the field of breath analysis for non-invasive health diagnostic. EBC sampling from human volunteers was performed under UC Davis IRB protocol 63701-3 (09/30/2014-07/07/2017). PMID:28004639

Human breath metabolomics using an optimized non-invasive exhaled breath condensate sampler.

PubMed

Zamuruyev, Konstantin O; Aksenov, Alexander A; Pasamontes, Alberto; Brown, Joshua F; Pettit, Dayna R; Foutouhi, Soraya; Weimer, Bart C; Schivo, Michael; Kenyon, Nicholas J; Delplanque, Jean-Pierre; Davis, Cristina E

2016-12-22

Exhaled breath condensate (EBC) analysis is a developing field with tremendous promise to advance personalized, non-invasive health diagnostics as new analytical instrumentation platforms and detection methods are developed. Multiple commercially-available and researcher-built experimental samplers are reported in the literature. However, there is very limited information available to determine an effective breath sampling approach, especially regarding the dependence of breath sample metabolomic content on the collection device design and sampling methodology. This lack of an optimal standard procedure results in a range of reported results that are sometimes contradictory. Here, we present a design of a portable human EBC sampler optimized for collection and preservation of the rich metabolomic content of breath. The performance of the engineered device is compared to two commercially available breath collection devices: the RTube ™ and TurboDECCS. A number of design and performance parameters are considered, including: condenser temperature stability during sampling, collection efficiency, condenser material choice, and saliva contamination in the collected breath samples. The significance of the biological content of breath samples, collected with each device, is evaluated with a set of mass spectrometry methods and was the primary factor for evaluating device performance. The design includes an adjustable mass-size threshold for aerodynamic filtering of saliva droplets from the breath flow. Engineering an inexpensive device that allows efficient collection of metalomic-rich breath samples is intended to aid further advancement in the field of breath analysis for non-invasive health diagnostic. EBC sampling from human volunteers was performed under UC Davis IRB protocol 63701-3 (09/30/2014-07/07/2017).

Cervical external immobilization devices: evaluation of magnetic resonance imaging issues at 3.0 Tesla.

PubMed

Diaz, Francis L; Tweardy, Lisa; Shellock, Frank G

2010-02-15

Laboratory investigation, ex vivo. Currently, no studies have addressed the magnetic resonance imaging (MRI) issues for cervical external immobilization devices at 3-Tesla. Under certain conditions significant heating may occur, resulting in patient burns. Furthermore, artifacts can be substantial and prevent the diagnostic use of MRI. Therefore, the objective of this investigation was to evaluate MRI issues for 4 different cervical external immobilization devices at 3-Tesla. Excessive heating and substantial artifacts are 2 potential complications associated with performing MRI at 3-Tesla in patients with cervical external immobilization devices. Using ex vivo testing techniques, MRI-related heating and artifacts were evaluated for 4 different cervical devices during MRI at 3-Tesla. Four cervical external immobilization devices (Generation 80, Resolve Ring and Superstructure, Resolve Ring and Jerome Vest/Jerome Superstructure, and the V1 Halo System; Ossur Americas, Aliso Viejo, CA) underwent MRI testing at 3-Tesla. All devices were made from nonmetallic or nonmagnetic materials. Heating was determined using a gelled-saline-filled skull phantom with fluoroptic thermometry probes attached to the skull pins. MRI was performed at 3-Tesla, using a high level of RF energy. Artifacts were assessed at 3-Tesla, using standard cervical imaging techniques. The Generation 80 and V1 Halo devices exhibited substantial temperature rises (11.6 degrees C and 8.5 degrees C, respectively), with "sparking" evident for the Generation 80 during the MRI procedure. Artifacts were problematic for these devices, as well. By comparison, the 2 Resolve Ring-based cervical external immobilization devices showed little or no heating (< or = 0.6 degrees C) and the artifacts were acceptable for diagnostic MRI examinations. The low degree of heating and minor artifacts associated with the Resolve-based cervical external immobilization devices indicated that these products are safe for patients undergoing MRI at 3-Tesla.

Evaluation of dowel bar alignment and effect on long-term performance of jointed concrete pavement.

DOT National Transportation Integrated Search

2013-09-01

Recent concerns of misaligned dowel bars led to a technical assistance project : to investigate the roadways in question using a MIT-SCAN-2 device borrowed : from the Federal Highway Administration (FHWA). The device worked extremely : well, and the ...

21 CFR 26.35 - Length and purpose of transition period.

Code of Federal Regulations, 2010 CFR

2010-04-01

... MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN MEDICAL DEVICE PRODUCT EVALUATION REPORTS: UNITED STATES AND THE EUROPEAN... bodies (CAB's) of the other party with respect to the ability to perform quality system and product...

Hybrid electro-optics and chipscale integration of electronics and photonics

NASA Astrophysics Data System (ADS)

Dalton, L. R.; Robinson, B. H.; Elder, D. L.; Tillack, A. F.; Johnson, L. E.

2017-08-01

Taken together, theory-guided nano-engineering of organic electro-optic materials and hybrid device architectures have permitted dramatic improvement of the performance of electro-optic devices. For example, the voltage-length product has been improved by nearly a factor of 104 , bandwidths have been extended to nearly 200 GHz, device footprints reduced to less than 200 μm2 , and femtojoule energy efficiency achieved. This presentation discusses the utilization of new coarse-grained theoretical methods and advanced quantum mechanical methods to quantitatively simulate the physical properties of new classes of organic electro-optic materials and to evaluate their performance in nanoscopic device architectures, accounting for the effect on chromophore ordering at interfaces in nanoscopic waveguides.

[Experiences and recommendations of the German Federal Institute for Drugs and Medical Devices (BfArM) concerning clinical investigation of medical devices and the evaluation of serious adverse events (SAE)].

PubMed

Renisch, B; Lauer, W

2014-12-01

An integral part of the conformity assessment process for medical devices is a clinical evaluation based on clinical data. Particularly in the case of implantable devices and products of risk class III clinical trials must be performed. Since March 2010 applications for the authorization of clinical trials as well as for the waiver of the authorization requirement must be submitted centrally in Germany to the appropriate federal authority, the Federal Institute for Drugs and Medical Devices (BfArM) or the Paul Ehrlich Institute (PEI). In addition to authorization, approval by the responsible ethics committee is also required under law in order to begin clinical testing of medical devices in Germany. In this paper, the legal framework for the clinical testing of medical devices as well as those involved and possible procedures including evaluation criteria for the initial application of a trial and subsequent amendments are presented in detail. In addition, the reporting requirements for serious adverse events (SAEs) are explained and possible consequences of the evaluation are presented. Finally, a summary of application and registration numbers for all areas of extensive experience of the BfArM as well as requests and guidance for applicants are presented.

Computerized screening devices and performance assessment: development of a policy towards automation. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

PubMed

Bartels, P H; Bibbo, M; Hutchinson, M L; Gahm, T; Grohs, H K; Gwi-Mak, E; Kaufman, E A; Kaufman, R H; Knight, B K; Koss, L G; Magruder, L E; Mango, L J; McCallum, S M; Melamed, M R; Peebles, A; Richart, R M; Robinowitz, M; Rosenthal, D L; Sauer, T; Schenck, U; Tanaka, N; Topalidis, T; Verhest, A P; Wertlake, P T; Wilbur, D C

1998-01-01

The extension of automation to the diagnostic assessment of clinical materials raises issues of professional responsibility, on the part of both the medical professional and designer of the device. The International Academy of Cytology (IAC) and other professional cytology societies should develop a policy towards automation in the diagnostic assessment of clinical cytologic materials. The following summarizes the discussion of the initial position statement at the International Expert Conference on Diagnostic Cytology Towards the 21st Century, Hawaii, June 1997. 1. The professional in charge of a clinical cytopathology laboratory continues to bear the ultimate medical responsibility for diagnostic decisions made at the facility, whether automated devices are involved or not. 2. The introduction of automated procedures into clinical cytology should under no circumstances lead to a lowering of standards of performance. A prime objective of any guidelines should be to ensure that an automated procedure, in principle, does not expose any patient to new risks, nor should it increase already-existing, inherent risks. 3. Automated devices should provide capabilities for the medical professional to conduct periodic tests of the appropriate performance of the device. 4. Supervisory personnel should continue visual quality control screening of a certain percentage of slides dismissed at primary screening as within normal limits (WNL), even when automated procedures are employed in the laboratory. 5. Specifications for the design of primary screening devices for the detection of cervical cancer issued by the IAC in 1984 were reaffirmed. 6. The setting of numeric performance criteria is the proper charge of regulatory agencies, which also have the power of enforcement. 7. Human expert verification of results represents the "gold standard" at this time. Performance characteristics of computerized cytology devices should be determined by adherence to defined and well-considered protocols. Manufacturers should not claim a new standard of care; this is the responsibility of the medical community and professional groups. 8. Cytology professionals should support the development of procedures that bring about an improvement in diagnostic decision making. Advances in technology should be adopted if they can help solve problems in clinical cytology. The introduction of automated procedures into diagnostic decision making should take place strictly under the supervision and with the active participation and critical evaluation by the professional cytology community. Guidelines should be developed for the communication of technical information about the performance of automated screening devices by the IAC to governmental agencies and national societies. Also, guidelines are necessary for the official communication of IAC concerns to industry, medicolegal entities and the media. Procedures and guidelines for the evaluation of studies pertaining to the performance of automated devices, performance metrics and definitions for evaluation criteria should be established.

Rapid screening, separation, and detection of hydroxyl radical scavengers from total flavonoids of Ginkgo biloba leaves by chromatography combined with molecular devices.

PubMed

Wang, Jing; Zheng, Meizhu; Chen, Lina; Liu, Zhiqiang; Zhang, Yuchi; Liu, Chun-Ming; Liu, Shu

2016-11-01

Hydroxyl radicals are the most reactive free radical of human body, a strong contributor to tissue damage. In this study, liquid chromatography coupled to electrospray ionization mass spectrometry was applied to screen and identify hydroxyl radical scavengers from the total flavonoids of Ginkgo biloba leaves, and high-performance counter current chromatography was used to separate and isolate the active compounds. Furthermore, molecular devices were used to determine hydroxyl radical scavenging activities of the obtained hydroxyl radical scavengers and other flavonoids from G. biloba leaves. As a result, six compounds were screened as hydroxyl radical scavengers, but only three flavonoids, namely, rutin, cosmos glycosides and apigenin-7-O-Glu-4'-O-Rha, were isolated successfully from total flavonoids by high-performance counter current chromatography. The purities of the three obtained compounds were over 90%, respectively, as determined by liquid chromatography. Molecular devices with 96-well microplates evaluation indicated that the 50% scavenging concentration values of screened compounds were lower than that of other flavonoids, they performed greater hydroxyl radical scavenging activity, and the evaluation effects were consistent with the liquid chromatography with mass spectrometry screening results. Therefore, chromatography combined with molecular devices is a feasible and an efficient method for systematic screening, identification, isolation, and evaluation of bioactive components in mixture of botanical medicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Performing magnetic resonance imaging in patients with implantable pacemakers and defibrillators: results of a European Heart Rhythm Association survey.

PubMed

Marinskis, Germanas; Bongiorni, Maria Grazia; Dagres, Nikolaos; Dobreanu, Dan; Lewalter, Thorsten; Blomström-Lundqvist, Carina

2012-12-01

The purpose of our survey was to evaluate the experience, current practice and attitudes of performing magnetic resonance imaging (MRI) studies in patients with cardiac implantable electronic devices. Fifty-one centre-members of European Heart Rhythm Association Research network have responded to the survey. According to the obtained data, 55.2% of responding centres do not perform MRI scans in patients with non-MRI-certified pacemakers and 65.8% in patients with such implantable cardioverter defibrillators (ICDs). Reported complication rate in patients with non-MRI-certified devices is low and conforms to the literature data. Experience with newer MRI-compatible pacemakers and ICDs is limited to single cases in most centres. This survey shows limited experience with performing MRI studies in patients with implanted pacemakers and ICDs. In concordance with available guidelines, most centres limit MRI scans in patients with non-MRI-certified devices. The implant numbers for MRI-certified devices and experience with performing MRI scans in these patients are still low.

Audiologic and subjective evaluation of Baha® Attract device.

PubMed

Pérez-Carbonell, Tomàs; Pla-Gil, Ignacio; Redondo-Martínez, Jaume; Morant-Ventura, Antonio; García-Callejo, Francisco Javier; Marco-Algarra, Jaime

We included 9 patients implanted with Baha ® Attract. All our patients were evaluated by free field tonal audiometry, free field verbal audiometry and free field verbal audiometry with background noise, all the tests were performed with and without the device. To evaluate the subjective component of the implantation, we used the Glasgow Benefit Inventory (GBI) and Abbreviated Profile of Hearing Aid Benefit (APHAB). The auditive assessment with the device showed average auditive thresholds of 35.8dB with improvements of 25.8dB over the previous situation. Speech reception thresholds were 37dB with Baha ® Attract, showing improvements of 23dB. Maximum discrimination thresholds showed an average gain of 60dB with the device. Baha ® Attract achieves auditive improvements in patients for whom it is correctly indicated, with a consequent positive subjective evaluation. This study shows the attenuation effect in transcutaneous transmission, that prevents the device achieving greater improvements. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

Design and Performance Evaluation of Sensors and Actuators for Advanced Optical Systems

NASA Technical Reports Server (NTRS)

Clark, Natalie

2011-01-01

Current state-of-the-art commercial sensors and actuators do not meet many of NASA s next generation spacecraft and instrument needs. Nor do they satisfy the DoD needs for satellite missions, especially micro/nano satellite missions. In an effort to develop advanced optical devices and instruments that meet mission requirements, NASA Langley recently completed construction of a new cleanroom housing equipment capable of fabricating high performance active optic and adaptive optic technologies including deformable mirrors, reconfigurable lenses (both refractive and diffractive), spectrometers, spectro-polarimeters, tunable filters and many other active optic devices. In addition to performance, these advanced optic technologies offer advantages in speed, size, weight, power consumption, and radiation tolerance. The active optic devices described in this paper rely on birefringent liquid crystal materials to alter either the phase or the polarization of the incoming light. Design considerations and performance evaluation results for various NASA applications are presented. Applications presented will include large space telescopes, optical communications, spacecraft windows, coronagraphs, and star trackers. Keywords: Photonics, Adaptive Optics, Tunable Filters, MEMs., MOEMs, Coronagraph, Star Tracker

Performance of ZnO based piezo-generators under controlled compression

NASA Astrophysics Data System (ADS)

Tao, Ran; Parmar, Mitesh; Ardila, Gustavo; Oliveira, Paulo; Marques, Daniel; Montès, Laurent; Mouis, Mireille

2017-06-01

This paper reports on the fabrication and characterization of ZnO based vertically integrated nanogenerator (VING) devices under controlled compression. The basic NG structure is a composite material integrating hydrothermally grown vertical piezoelectric zinc oxide (ZnO) nanowires (NWs) into a dielectric matrix (PMMA). A specific characterization set-up has been developed to control the applied compression and the perpendicularity of the applied force on the devices. The role of different fabrication parameters has been evaluated experimentally and compared with previously reported theoretical models, including the thickness of the top PMMA layer and the density of the NWs array in the matrix. Finally, the performance of the VING structure has been evaluated experimentally for different resistive loads obtaining a power density of 85 μW cm-3 considering only the active layer of the device. This has been compared to the performance of a commercial bulk layer of PZT (25 μW cm-3) under the same applied force of 5 N.

Motion compensation for MRI-compatible patient-mounted needle guide device: estimation of targeting accuracy in MRI-guided kidney cryoablations

NASA Astrophysics Data System (ADS)

Tokuda, Junichi; Chauvin, Laurent; Ninni, Brian; Kato, Takahisa; King, Franklin; Tuncali, Kemal; Hata, Nobuhiko

2018-04-01

Patient-mounted needle guide devices for percutaneous ablation are vulnerable to patient motion. The objective of this study is to develop and evaluate a software system for an MRI-compatible patient-mounted needle guide device that can adaptively compensate for displacement of the device due to patient motion using a novel image-based automatic device-to-image registration technique. We have developed a software system for an MRI-compatible patient-mounted needle guide device for percutaneous ablation. It features fully-automated image-based device-to-image registration to track the device position, and a device controller to adjust the needle trajectory to compensate for the displacement of the device. We performed: (a) a phantom study using a clinical MR scanner to evaluate registration performance; (b) simulations using intraoperative time-series MR data acquired in 20 clinical cases of MRI-guided renal cryoablations to assess its impact on motion compensation; and (c) a pilot clinical study in three patients to test its feasibility during the clinical procedure. FRE, TRE, and success rate of device-to-image registration were mm, mm, and 98.3% for the phantom images. The simulation study showed that the motion compensation reduced the targeting error for needle placement from 8.2 mm to 5.4 mm (p  <  0.0005) in patients under general anesthesia (GA), and from 14.4 mm to 10.0 mm () in patients under monitored anesthesia care (MAC). The pilot study showed that the software registered the device successfully in a clinical setting. Our simulation study demonstrated that the software system could significantly improve targeting accuracy in patients treated under both MAC and GA. Intraprocedural image-based device-to-image registration was feasible.

Towards standardized assessment of endoscope optical performance: geometric distortion

NASA Astrophysics Data System (ADS)

Wang, Quanzeng; Desai, Viraj N.; Ngo, Ying Z.; Cheng, Wei-Chung; Pfefer, Joshua

2013-12-01

Technological advances in endoscopes, such as capsule, ultrathin and disposable devices, promise significant improvements in safety, clinical effectiveness and patient acceptance. Unfortunately, the industry lacks test methods for preclinical evaluation of key optical performance characteristics (OPCs) of endoscopic devices that are quantitative, objective and well-validated. As a result, it is difficult for researchers and developers to compare image quality and evaluate equivalence to, or improvement upon, prior technologies. While endoscope OPCs include resolution, field of view, and depth of field, among others, our focus in this paper is geometric image distortion. We reviewed specific test methods for distortion and then developed an objective, quantitative test method based on well-defined experimental and data processing steps to evaluate radial distortion in the full field of view of an endoscopic imaging system. Our measurements and analyses showed that a second-degree polynomial equation could well describe the radial distortion curve of a traditional endoscope. The distortion evaluation method was effective for correcting the image and can be used to explain other widely accepted evaluation methods such as picture height distortion. Development of consensus standards based on promising test methods for image quality assessment, such as the method studied here, will facilitate clinical implementation of innovative endoscopic devices.

Performance Evaluation Methods for Assistive Robotic Technology

NASA Astrophysics Data System (ADS)

Tsui, Katherine M.; Feil-Seifer, David J.; Matarić, Maja J.; Yanco, Holly A.

Robots have been developed for several assistive technology domains, including intervention for Autism Spectrum Disorders, eldercare, and post-stroke rehabilitation. Assistive robots have also been used to promote independent living through the use of devices such as intelligent wheelchairs, assistive robotic arms, and external limb prostheses. Work in the broad field of assistive robotic technology can be divided into two major research phases: technology development, in which new devices, software, and interfaces are created; and clinical, in which assistive technology is applied to a given end-user population. Moving from technology development towards clinical applications is a significant challenge. Developing performance metrics for assistive robots poses a related set of challenges. In this paper, we survey several areas of assistive robotic technology in order to derive and demonstrate domain-specific means for evaluating the performance of such systems. We also present two case studies of applied performance measures and a discussion regarding the ubiquity of functional performance measures across the sampled domains. Finally, we present guidelines for incorporating human performance metrics into end-user evaluations of assistive robotic technologies.

Local rollback for fault-tolerance in parallel computing systems

DOEpatents

Blumrich, Matthias A [Yorktown Heights, NY; Chen, Dong [Yorktown Heights, NY; Gara, Alan [Yorktown Heights, NY; Giampapa, Mark E [Yorktown Heights, NY; Heidelberger, Philip [Yorktown Heights, NY; Ohmacht, Martin [Yorktown Heights, NY; Steinmacher-Burow, Burkhard [Boeblingen, DE; Sugavanam, Krishnan [Yorktown Heights, NY

2012-01-24

A control logic device performs a local rollback in a parallel super computing system. The super computing system includes at least one cache memory device. The control logic device determines a local rollback interval. The control logic device runs at least one instruction in the local rollback interval. The control logic device evaluates whether an unrecoverable condition occurs while running the at least one instruction during the local rollback interval. The control logic device checks whether an error occurs during the local rollback. The control logic device restarts the local rollback interval if the error occurs and the unrecoverable condition does not occur during the local rollback interval.

Basic life support: evaluation of learning using simulation and immediate feedback devices1.

PubMed

Tobase, Lucia; Peres, Heloisa Helena Ciqueto; Tomazini, Edenir Aparecida Sartorelli; Teodoro, Simone Valentim; Ramos, Meire Bruna; Polastri, Thatiane Facholi

2017-10-30

to evaluate students' learning in an online course on basic life support with immediate feedback devices, during a simulation of care during cardiorespiratory arrest. a quasi-experimental study, using a before-and-after design. An online course on basic life support was developed and administered to participants, as an educational intervention. Theoretical learning was evaluated by means of a pre- and post-test and, to verify the practice, simulation with immediate feedback devices was used. there were 62 participants, 87% female, 90% in the first and second year of college, with a mean age of 21.47 (standard deviation 2.39). With a 95% confidence level, the mean scores in the pre-test were 6.4 (standard deviation 1.61), and 9.3 in the post-test (standard deviation 0.82, p <0.001); in practice, 9.1 (standard deviation 0.95) with performance equivalent to basic cardiopulmonary resuscitation, according to the feedback device; 43.7 (standard deviation 26.86) mean duration of the compression cycle by second of 20.5 (standard deviation 9.47); number of compressions 167.2 (standard deviation 57.06); depth of compressions of 48.1 millimeter (standard deviation 10.49); volume of ventilation 742.7 (standard deviation 301.12); flow fraction percentage of 40.3 (standard deviation 10.03). the online course contributed to learning of basic life support. In view of the need for technological innovations in teaching and systematization of cardiopulmonary resuscitation, simulation and feedback devices are resources that favor learning and performance awareness in performing the maneuvers.

Belgian guidelines for economic evaluations: second edition.

PubMed

Thiry, Nancy; Neyt, Mattias; Van De Sande, Stefaan; Cleemput, Irina

2014-12-01

The aim of this study was to present the updated methodological guidelines for economic evaluations of healthcare interventions (drugs, medical devices, and other interventions) in Belgium. The update of the guidelines was performed by three Belgian health economists following feedback from users of the former guidelines and personal experience. The updated guidelines were discussed with a multidisciplinary team consisting of other health economists, assessors of reimbursement request files, representatives of Belgian databases and representatives of the drugs and medical devices industry. The final document was validated by three external validators that were not involved in the previous discussions. The guidelines give methodological guidance for the following components of an economic evaluation: literature review, perspective of the evaluation, definition of the target population, choice of the comparator, analytic technique and study design, calculation of costs, valuation of outcomes, definition of the time horizon, modeling, handling uncertainty and discounting. We present a reference case that can be considered as the minimal requirement for Belgian economic evaluations of health interventions. These guidelines will improve the methodological quality, transparency and uniformity of the economic evaluations performed in Belgium. The guidelines will also provide support to the researchers and assessors performing or evaluating economic evaluations.

Analysis of Al2O3—parylene C bilayer coatings and impact of microelectrode topography on long term stability of implantable neural arrays

NASA Astrophysics Data System (ADS)

Caldwell, Ryan; Mandal, Himadri; Sharma, Rohit; Solzbacher, Florian; Tathireddy, Prashant; Rieth, Loren

2017-08-01

Objective. Performance of many dielectric coatings for neural electrodes degrades over time, contributing to loss of neural signals and evoked percepts. Studies using planar test substrates have found that a novel bilayer coating of atomic-layer deposited (ALD) Al2O3 and parylene C is a promising candidate for neural electrode applications, exhibiting superior stability to parylene C alone. However, initial results from bilayer encapsulation testing on non-planar devices have been less positive. Our aim was to evaluate ALD Al2O3-parylene C coatings using novel test paradigms, to rigorously evaluate dielectric coatings for neural electrode applications by incorporating neural electrode topography into test structure design. Approach. Five test devices incorporated three distinct topographical features common to neural electrodes, derived from the utah electrode array (UEA). Devices with bilayer (52 nm Al2O3  +  6 µm parylene C) were evaluated against parylene C controls (N  ⩾  6 per device type). Devices were aged in phosphate buffered saline at 67 °C for up to 311 d, and monitored through: (1) leakage current to evaluate encapsulation lifetimes (>1 nA during 5VDC bias indicated failure), and (2) wideband (1-105 Hz) impedance. Main results. Mean-times-to-failure (MTTFs) ranged from 12 to 506 d for bilayer-coated devices, versus 10 to  >2310 d for controls. Statistical testing (log-rank test, α  =  0.05) of failure rates gave mixed results but favored the control condition. After failure, impedance loss for bilayer devices continued for months and manifested across the entire spectrum, whereas the effect was self-limiting after several days, and restricted to frequencies  <100 Hz for controls. These results correlated well with observations of UEAs encapsulated with bilayer and control films. Significance. We observed encapsulation failure modes and behaviors comparable to neural electrode performance which were undetected in studies with planar test devices. We found the impact of parylene C defects to be exacerbated by ALD Al2O3, and conclude that inferior bilayer performance arises from degradation of ALD Al2O3 when directly exposed to saline. This is an important consideration, given that neural electrodes with bilayer coatings are expected to have ALD Al2O3 exposed at dielectric boundaries that delineate electrode sites. Process improvements and use of different inorganic coatings to decrease dissolution in physiological fluids may improve performance. Testing frameworks which take neural electrode complexities into account will be well suited to reliably evaluate such encapsulation schemes.

Technological innovation in neurosurgery: a quantitative study.

PubMed

Marcus, Hani J; Hughes-Hallett, Archie; Kwasnicki, Richard M; Darzi, Ara; Yang, Guang-Zhong; Nandi, Dipankar

2015-07-01

Technological innovation within health care may be defined as the introduction of a new technology that initiates a change in clinical practice. Neurosurgery is a particularly technology-intensive surgical discipline, and new technologies have preceded many of the major advances in operative neurosurgical techniques. The aim of the present study was to quantitatively evaluate technological innovation in neurosurgery using patents and peer-reviewed publications as metrics of technology development and clinical translation, respectively. The authors searched a patent database for articles published between 1960 and 2010 using the Boolean search term "neurosurgeon OR neurosurgical OR neurosurgery." The top 50 performing patent codes were then grouped into technology clusters. Patent and publication growth curves were then generated for these technology clusters. A top-performing technology cluster was then selected as an exemplar for a more detailed analysis of individual patents. In all, 11,672 patents and 208,203 publications related to neurosurgery were identified. The top-performing technology clusters during these 50 years were image-guidance devices, clinical neurophysiology devices, neuromodulation devices, operating microscopes, and endoscopes. In relation to image-guidance and neuromodulation devices, the authors found a highly correlated rapid rise in the numbers of patents and publications, which suggests that these are areas of technology expansion. An in-depth analysis of neuromodulation-device patents revealed that the majority of well-performing patents were related to deep brain stimulation. Patent and publication data may be used to quantitatively evaluate technological innovation in neurosurgery.

Potential of a suite of robot/computer-assisted motivating systems for personalized, home-based, stroke rehabilitation.

PubMed

Johnson, Michelle J; Feng, Xin; Johnson, Laura M; Winters, Jack M

2007-03-01

There is a need to improve semi-autonomous stroke therapy in home environments often characterized by low supervision of clinical experts and low extrinsic motivation. Our distributed device approach to this problem consists of an integrated suite of low-cost robotic/computer-assistive technologies driven by a novel universal access software framework called UniTherapy. Our design strategy for personalizing the therapy, providing extrinsic motivation and outcome assessment is presented and evaluated. Three studies were conducted to evaluate the potential of the suite. A conventional force-reflecting joystick, a modified joystick therapy platform (TheraJoy), and a steering wheel platform (TheraDrive) were tested separately with the UniTherapy software. Stroke subjects with hemiparesis and able-bodied subjects completed tracking activities with the devices in different positions. We quantify motor performance across subject groups and across device platforms and muscle activation across devices at two positions in the arm workspace. Trends in the assessment metrics were consistent across devices with able-bodied and high functioning strokes subjects being significantly more accurate and quicker in their motor performance than low functioning subjects. Muscle activation patterns were different for shoulder and elbow across different devices and locations. The Robot/CAMR suite has potential for stroke rehabilitation. By manipulating hardware and software variables, we can create personalized therapy environments that engage patients, address their therapy need, and track their progress. A larger longitudinal study is still needed to evaluate these systems in under-supervised environments such as the home.

Evaluation of Various Tack Coat Materials Using Interface Shear Device and Recommendations on a Simplified Device

DOT National Transportation Integrated Search

2017-12-01

The performance of pavement interface bonds affects the integrity of pavement structures. In current practice, tack coats are used to ensure sufficient bonding between asphalt concrete (AC) layers as well as AC and concrete or aggregate base layers. ...

Study on the system-level test method of digital metering in smart substation

NASA Astrophysics Data System (ADS)

Zhang, Xiang; Yang, Min; Hu, Juan; Li, Fuchao; Luo, Ruixi; Li, Jinsong; Ai, Bing

2017-03-01

Nowadays, the test methods of digital metering system in smart substation are used to test and evaluate the performance of a single device, but these methods can only effectively guarantee the accuracy and reliability of the measurement results of a digital metering device in a single run, it does not completely reflect the performance when each device constitutes a complete system. This paper introduced the shortages of the existing test methods. A system-level test method of digital metering in smart substation was proposed, and the feasibility of the method was proved by the actual test.

Response of surge protection devices to fast rising pulses

NASA Technical Reports Server (NTRS)

Mindel, I. N.

1980-01-01

Two types of lightning protection modules incorporating leadless (pill type) Zener like devices were evaluated with regard to their ability to suppress EMP induced transients. Two series of tests were performed to evaluate the ability of these modules to react to fast rate of rise ( 1Kv/ns) transients, and the attenuation introduced and the ability to limit damped sinusoid pulses which may be induced due to an EMP resulting from a nuclear detonation.

Safety, efficacy, and performance of implanted recycled cardiac rhythm management (CRM) devices in underprivileged patients.

PubMed

Hasan, Reema; Ghanbari, Hamid; Feldman, Dustin; Menesses, Daniel; Rivas, Daniel; Zakhem, Nicole C; Duarte, Carlos; Machado, Christian

2011-06-01

Patients in underdeveloped nations have limited access to life-saving medical technology including cardiac rhythm management (CRM) devices. We evaluated alternative means to provide such technology to this patient population while assessing the safety and efficacy of such a practice. Patients in the United States with clinical indications for extraction of CRM devices were consented. Antemortem CRM devices were cleaned and sterilized following a protocol established at our institution. Surveillance in vitro cultures were performed for quality assurance. The functional status of pulse generators was tested with a pacing system analyzer to confirm at least 70% battery life. Most generators were transported, in person, to an implanting institution in Nicaragua. Recipients with a Class I indication for CRM implantation, and meeting economical criteria set forth, were consented for implantation of a recycled device. Between 2003 and 2009, implantation was performed in 17 patients with an average age of 42.1 ± 20.3 years. Of the 17 patients, nine were male and eight were female. Mean follow-up was 68 ± 38 months. Device evaluation occurred prior to discharge, 4 weeks post implantation, and every 6 months thereafter. There were three deaths during the follow-up period secondary to myocardial infarction, stroke, and heart failure. Hematoma formation occurred in one patient. No infections, early battery depletion, or device malfunction were identified during follow-up. Our case series is the longest follow-up of recipients of recycled antemortem CRM devices. Our findings support the feasibility and safety of this alternative acquisition of life-saving technology. ©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.

Evaluation of the VTI ECI-1 corrosion monitoring device.

DOT National Transportation Integrated Search

2006-01-01

This report describes an evaluation performed by the California Department of Transportation (Department) of the : ECI-1 Embedded Corrosion Instrument, developed by Virginia Technologies, Incorporated (VTI). : The ECI-1 Embedded Corrosion Instrument ...

Performance Evaluation of a High Bandwidth Liquid Fuel Modulation Valve for Active Combustion Control

NASA Technical Reports Server (NTRS)

Saus, Joseph R.; DeLaat, John C.; Chang, Clarence T.; Vrnak, Daniel R.

2012-01-01

At the NASA Glenn Research Center, a characterization rig was designed and constructed for the purpose of evaluating high bandwidth liquid fuel modulation devices to determine their suitability for active combustion control research. Incorporated into the rig s design are features that approximate conditions similar to those that would be encountered by a candidate device if it were installed on an actual combustion research rig. The characterized dynamic performance measures obtained through testing in the rig are planned to be accurate indicators of expected performance in an actual combustion testing environment. To evaluate how well the characterization rig predicts fuel modulator dynamic performance, characterization rig data was compared with performance data for a fuel modulator candidate when the candidate was in operation during combustion testing. Specifically, the nominal and off-nominal performance data for a magnetostrictive-actuated proportional fuel modulation valve is described. Valve performance data were collected with the characterization rig configured to emulate two different combustion rig fuel feed systems. Fuel mass flows and pressures, fuel feed line lengths, and fuel injector orifice size was approximated in the characterization rig. Valve performance data were also collected with the valve modulating the fuel into the two combustor rigs. Comparison of the predicted and actual valve performance data show that when the valve is operated near its design condition the characterization rig can appropriately predict the installed performance of the valve. Improvements to the characterization rig and accompanying modeling activities are underway to more accurately predict performance, especially for the devices under development to modulate fuel into the much smaller fuel injectors anticipated in future lean-burning low-emissions aircraft engine combustors.

Design and evaluation of cellular power converter architectures

NASA Astrophysics Data System (ADS)

Perreault, David John

Power electronic technology plays an important role in many energy conversion and storage applications, including machine drives, power supplies, frequency changers and UPS systems. Increases in performance and reductions in cost have been achieved through the development of higher performance power semiconductor devices and integrated control devices with increased functionality. Manufacturing techniques, however, have changed little. High power is typically achieved by paralleling multiple die in a sing!e package, producing the physical equivalent of a single large device. Consequently, both the device package and the converter in which the device is used continue to require large, complex mechanical structures, and relatively sophisticated heat transfer systems. An alternative to this approach is the use of a cellular power converter architecture, which is based upon the parallel connection of a large number of quasi-autonomous converters, called cells, each of which is designed for a fraction of the system rating. The cell rating is chosen such that single-die devices in inexpensive packages can be used, and the cell fabricated with an automated assembly process. The use of quasi-autonomous cells means that system performance is not compromised by the failure of a cell. This thesis explores the design of cellular converter architectures with the objective of achieving improvements in performance, reliability, and cost over conventional converter designs. New approaches are developed and experimentally verified for highly distributed control of cellular converters, including methods for ripple cancellation and current-sharing control. The performance of these techniques are quantified, and their dynamics are analyzed. Cell topologies suitable to the cellular architecture are investigated, and their use for systems in the 5-500 kVA range is explored. The design, construction, and experimental evaluation of a 6 kW cellular switched-mode rectifier is also addressed. This cellular system implements entirely distributed control, and achieves performance levels unattainable with an equivalent single converter. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Infrared charge-injection-device array performance at low background

NASA Technical Reports Server (NTRS)

Mccreight, C. R.; Goebel, J. H.

1981-01-01

Low-background tests of a 1 x 32 Si:Bi charge-injection-device (CID) IR detector are carried out to evaluate its feasibility for space-based astronomical observations. Optimum performance is obtained at a temperature of 11 K. The sensitivity is found to compare well with that of discrete extrinsic silicon photoconductors. The measured sensitivity and the apparent absence of anomalous effects make extrinsic silicon CID arrays very promising for astronomical applications.

Program for the development of high temperature electrical materials and components

NASA Technical Reports Server (NTRS)

Neff, W. S.; Lowry, L. R.

1972-01-01

Evaluation of high temperature, space-vacuum performance of selected electrical materials and components, high temperature capacitor development, and evaluation, construction, and endurance testing of compression sealed pyrolytic boron nitride slot insulation are described. The first subject above covered the aging evaluation of electrical devices constructed from selected electrical materials. Individual materials performances were also evaluated and reported. The second subject included study of methods of improving electrical performance of pyrolytic boron nitride capacitors. The third portion was conducted to evaluate the thermal and electrical performance of pyrolytic boron nitride as stator slot liner material under varied temperature and compressive loading. Conclusions and recommendations are presented.

78 FR 75571 - Independent Assessment of the Process for the Review of Device Submissions; High Priority...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-12

... of performing the technical analysis, management assessment, and program evaluation tasks required to.... Analysis of elements of the review process (including the presubmission process, and investigational device... time to facilitate a more efficient process. This includes analysis of root causes for inefficiencies...

Power Doppler ultrasonography and synovitis: correlating ultrasound imaging with histopathological findings and evaluating the performance of ultrasound equipments.

PubMed

Koski, J M; Saarakkala, S; Helle, M; Hakulinen, U; Heikkinen, J O; Hermunen, H

2006-12-01

To examine the validity of power Doppler ultrasound imaging to identify synovitis, using histopathology as gold standard, and to assess the performance of ultrasound equipments. 44 synovial sites in small and large joints, bursae and tendon sheaths were depicted with ultrasound. A synovial biopsy was performed on the site depicted and a synovial sample was taken for histopathological evaluation. The performance of three ultrasound devices was tested using flow phantoms. A positive Doppler signal was detected in 29 of 35 (83%) of the patients with active histological inflammation. In eight additional samples, histological examination showed other pathological synovial findings and a Doppler signal was detected in five of them. No significant correlation was found between the amount of Doppler signal and histological synovitis score (r = 0.239, p = NS). The amount of subsynovial infiltration of polymorphonuclear leucocytes and surface fibrin correlated significantly with the amount of power Doppler signal: r = 0.397 (p<0.01) and 0.328 (p<0.05), respectively. The ultrasound devices differed in showing the smallest detectable flow. A negative Doppler signal does not exclude the possibility of synovitis. A positive Doppler signal in the synovium is an indicator of an active synovial inflammation in patients. A Doppler signal does not correlate with the extent of the inflammation and it can also be seen in other synovial reactions. It is important that the quality measurements of ultrasound devices are reported, because the results should be evaluated against the quality of the device used.

Design, characterisation and evaluation of a soft robotic sock device on healthy subjects for assisted ankle rehabilitation.

PubMed

Low, Fan-Zhe; Lim, Jeong Hoon; Yeow, Chen-Hua

2018-01-01

Motor impairment is one of the common neurological conditions suffered by stroke patients, where this chronic immobility together with the absence of early limb mobilisation can lead to conditions such as joint contracture with spastic limbs. In this study, a soft robotic sock device was developed, which can provide compliant actuation to the ankle joint in the early stage of stroke recovery. The device is fitted with soft extension actuators and when the actuators are inflated, they extend and guide the foot into plantarflexion; upon deflation, the actuators will resume their initial conformations. Each actuator is linked to a pneumatic pump-valve control system that injects pressurised air into or release air from the system. In this study, the design and characterisation of the soft actuators will be presented, where the theoretical and experimental forces generated by the actuators were compared. The performance of the device was also evaluated on healthy subjects and the results had shown that the device was able to move the subjects' ankles into cycles of dorsiflexion-plantarflexion, in the absence of voluntary muscle effort. The findings suggested that the soft wearable robotic device was capable of assisting the subjects in performing repeated cycles of ankle flexion.

Design, fabrication, and delivery of a charge injection device as a stellar tracking device

NASA Technical Reports Server (NTRS)

Burke, H. K.; Michon, G. J.; Tomlinson, H. W.; Vogelsong, T. L.; Grafinger, A.; Wilson, R.

1979-01-01

Six 128 x 128 CID imagers fabricated on bulk silicon and with thin polysilicon upper-level electrodes were tested in a star tracking mode. Noise and spectral response were measured as a function of temperature over the range of +25 C to -40 C. Noise at 0 C and below was less than 40 rms carriers/pixel for all devices at an effective noise bandwidth of 150 Hz. Quantum yield for all devices averaged 40% from 0.4 to 1.0 microns with no measurable temperature dependence. Extrapolating from these performance parameters to those of a large (400 x 400) array and accounting for design and processing improvements, indicates that the larger array would show a further improvement in noise performance -- on the order of 25 carriers. A preliminary evaluation of the projected performance of the 400 x 400 array and a representative set of star sensor requirements indicates that the CID has excellent potential as a stellar tracking device.

Diagnostic accuracy of an iPhone DICOM viewer for the interpretation of magnetic resonance imaging of the knee.

PubMed

De Maio, Peter; White, Lawrence M; Bleakney, Robert; Menezes, Ravi J; Theodoropoulos, John

2014-07-01

To evaluate the diagnostic performance of viewing magnetic resonance (MR) images on a handheld mobile device compared with a conventional radiology workstation for the diagnosis of intra-articular knee pathology. Prospective comparison study. Tertiary care center. Fifty consecutive subjects who had MR imaging of the knee followed by knee arthroscopy were prospectively evaluated. Two musculoskeletal radiologists independently reviewed each MR study using 2 different viewers: the OsiriX DICOM viewer software on an Apple iPhone 3GS device and eFilm Workstation software on a conventional picture archiving and communications system workstation. Sensitivity and specificity of the iPhone and workstation interpretations was performed using knee arthroscopy as the reference standard. Intraobserver concordance and agreement between the iPhone and workstation interpretations were determined. There was no statistically significant difference between the 2 devices for each paired comparison of diagnostic performance. For the iPhone interpretations, sensitivity ranged from 77% (13 of 17) for the lateral meniscus to 100% (17 of 17) for the anterior cruciate ligament. Specificity ranged from 74% (14 of 19) for cartilage to 100% (50 of 50) for the posterior cruciate ligament. There was a very high level of interobserver and intraobserver agreement between devices and readers. The iPhone reads took longer than the corresponding workstation reads, with a significant mean difference between the iPhone and workstation reads of 3.98 minutes (P < 0.001). The diagnostic performance of interpreting MR images on a handheld mobile device for the assessment of intra-articular knee pathology is similar to that of a conventional radiology workstation, however, requires a longer viewing time. Timely and accurate interpretation of complex medical images using mobile device solutions could result in new workflow efficiencies and ultimately improve patient care.

Manufacturer evaluations of endograft modifications.

PubMed

Waninger, Matthew S; Whirley, Robert G; Smith, Louis J; Wolf, Ben S

2013-03-01

The motivation to modify the design of a vascular device can arise from a number of sources. Clinical experience with the unmodified device could suggest new design modifications to improve device performance or clinical outcomes. Similarly, clinical success with a device often suggests modifications that could broaden the applicability of the device to enable treatment of different or more advanced disease states. As a specific example, both of these scenarios have arisen during the last decade in the evolution of endovascular grafts for the treatment of abdominal aortic aneurysms, with modifications enabling the treatment of patients with shorter infrarenal necks, more angulated anatomy, and smaller access vessels. These modifications have been made by manufacturers and additionally by physicians who create branched and fenestrated devices. The experience to date with the use of fenestrated devices and the development of chimney, snorkel, and periscope techniques suggests that modifications to off-the-shelf devices may provide some clinical benefit. This experience provides additional motivation for manufacturers to develop devices to address the clinical needs not met with their current product lines. For manufacturers, the device development process includes an assessment of the new device design to determine the appropriate evaluation strategy to support the safety and effectiveness of the modified device. This report provides a high-level overview of the process generally followed by device manufacturers to evaluate a proposed device modification before market release, in accordance with local country regulations and recognized international standards such as the International Organization of Standardization (ISO) standards for endovascular grafts (ISO 25539 Part 1). Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Bench evaluation: three face-shield CPR barrier devices.

PubMed

Simmons, M; Deao, D; Moon, L; Peters, K; Cavanaugh, S

1995-06-01

Due to the fear of disease transmission, the practice of mouth-to-mouth (M-M) rescue breathing is rarely performed; to address this concern, many types of CPR barrier devices have been developed. These include bag-valve-mask devices, mouth-to-mask devices, and face shields (FS). The purpose of this study was to measure the volumes delivered during mouth-to-face shield (M-FS) breathing, to measure the back pressure and calculate the resistance to flow through their 1-way valves, and to test for backward leak of gas through the valves. Three FS brands were evaluated: Kiss of Life (KOL), MicroSHIELD (Micro) and Res-Cue Key (RCK). Volume delivered during M-M and M-FS breathing was evaluated by 10 rescuers who used the devices while performing rescue breathing on a CPR mannequin. Back pressure was measured and resistance calculated by directing airflow through the 1-way valves. Backward leak was evaluated by measuring the O2 concentration at the rescuer side of the valve while 100% O2 was directed toward the patient side of the valve. Differences among the brands were evaluated using analysis of variance. The mean (SD) values for volumes in L were: M-M 1.00 (0.25), Micro 0.77 (0.20), RCK 0.64 (0.10), and KOL 0.24 (0.11). Mean values for back pressure in cm H2O at 50 L/min were Micro 16.7 (1.29), KOL 7.22 (0.13), and RCK 2.15 (0.16). Significant backward leak only occurred with RCK. Not one of the FSs tested met all of the requirements suggested by the American Heart Association and by the International Standards Organization.

Effectiveness of a personalized device in the evaluation of mandibular second molar periodontal healing after surgical extraction of adjacent third molar.

PubMed

Pippi, Roberto

2013-01-01

The primary aim of the present study was to validate the effectiveness of a personalized device able to guide periodontal probing in evaluation of second molar periodontal healing after adjacent third molar surgical extraction. Secondarily, the study analyzed if any patient and tooth related factors affected the second molar periodontal healing as well as if they were able to affect the periodontal probing depth performed with or without the personalized device. Thirty-five lower second molars were evaluated after extraction of the adjacent third molar. Pre-operative as well as 3 and 12 month post-operative probing depths of the distal surface of the second molar were evaluated. All measurements were taken by two different methods: standard two-point and four-point probing using a personalized onlay-type guide. Periapical radiographs were also evaluated. The Pearson product moment and the general linear model with backward stepwise procedure were used for inferential statistics. The mean 12-month post-operative probing depth/mean pre-operative probing depth ratio obtained with the guided probing method showed a highly significant effect on the 12-month radiographic post-operative/pre-operative radiographic measure ratio. None of the examined patient- or tooth-related factors showed a significant effect on pre-operative/12-month post-operative radiographic measure ratio. The use of the proposed personalized device seems to provide a more reliable estimate of second molar periodontal healing after adjacent third molar surgical extraction. No patient-or tooth-related factors seem to be able to affect either second molar periodontal healing or probing depth measures obtained with or without the personalized device in individuals younger than 25 years old. It can be therefore recommended that lower third molar surgical extraction be performed in young adults.

Improving the light-emitting properties of single-layered polyfluorene light-emitting devices by simple ionic liquid blending

NASA Astrophysics Data System (ADS)

Horike, Shohei; Nagaki, Hiroto; Misaki, Masahiro; Koshiba, Yasuko; Morimoto, Masahiro; Fukushima, Tatsuya; Ishida, Kenji

2018-03-01

This paper describes an evaluation of ionic liquids (ILs) as potential electrolytes for single-layered light-emitting devices with good emission performance. As optoelectronic devices continue to grow in abundance, high-performance light-emitting devices with a single emission layer are becoming increasingly important for low-cost production. We show that a simple technique of osmosing IL into the polymer layer can result in high luminous efficiency and good response times of single-layered light-emitting polymers, even without the additional stacking of charge carrier injection and transport layers. The IL contributions to the light-emission of the polymer are discussed from the perspectives of energy diagrams and of the electric double layers on the electrodes. Our findings enable a faster, cheaper, and lower-in-waste production of light-emitting devices.

Evaluation of performance, acceptance, and compliance of an auto-injector in healthy and rheumatoid arthritic subjects measured by a motion capture system.

PubMed

Xiao, Xiao; Li, Wei; Clawson, Corbin; Karvani, David; Sondag, Perceval; Hahn, James K

2018-01-01

The study aimed to develop a motion capture system that can track, visualize, and analyze the entire performance of self-injection with the auto-injector. Each of nine healthy subjects and 29 rheumatoid arthritic (RA) patients with different degrees of hand disability performed two simulated injections into an injection pad while six degrees of freedom (DOF) motions of the auto-injector and the injection pad were captured. We quantitatively measured the performance of the injection by calculating needle displacement from the motion trajectories. The max, mean, and SD of needle displacement were analyzed. Assessments of device acceptance and usability were evaluated by a survey questionnaire and independent observations of compliance with the device instruction for use (IFU). A total of 80 simulated injections were performed. Our results showed a similar level of performance among all the subjects with slightly larger, but not statistically significant, needle displacement in the RA group. In particular, no significant effects regarding previous experience in self-injection, grip method, pain in hand, and Cochin score in the RA group were found to have an impact on the mean needle displacement. Moreover, the analysis of needle displacement for different durations of injections indicated that most of the subjects reached their personal maximum displacement in 15 seconds and remained steady or exhibited a small amount of increase from 15 to 60 seconds. Device acceptance was high for most of the questions (ie, >4; >80%) based on a 0-5-point scale or percentage of acceptance. The overall compliance with the device IFU was high for the first injection (96.05%) and reached 98.02% for the second injection. We demonstrated the feasibility of tracking the motions of injection to measure the performance of simulated self-injection. The comparisons of needle displacement showed that even RA patients with severe hand disability could properly perform self-injection with this auto-injector at a similar level with the healthy subjects. Finally, the observed high device acceptance and compliance with device IFU suggest that the system is convenient and easy to use.

Performance Evaluation of Low Cost LoRa Modules in IoT Applications

NASA Astrophysics Data System (ADS)

Daud, Shuhaizar; Shi Yang, Teoh; Asmi Romli, Muhamad; Awang Ahmad, Zahari; Mahrom, Norfadila; Raof, Rafikha Aliana A.

2018-03-01

LoRa is a low power long range wireless communication platform that is designed as an efficient communication platform for small, low powered devices. This makes it very suitable for battery powered devices and IoT implementation. This paper evaluates some low cost LoRa modules available on the market and their suitability, energy efficiency and performance during operation. Two low cost LoRa transceiver from Semtech Industries, the SX1272 and SX1278 were tested for their power consumption and maximum transmission range. This study have evaluated the two LoRa solutions and found that the SX1278 have a better transmission range and uses lower energy compared to the SX1272 thus making it more suitable for embedded implementation as a data gateway.

A comparison of statistical methods for evaluating matching performance of a biometric identification device: a preliminary report

NASA Astrophysics Data System (ADS)

Schuckers, Michael E.; Hawley, Anne; Livingstone, Katie; Mramba, Nona

2004-08-01

Confidence intervals are an important way to assess and estimate a parameter. In the case of biometric identification devices, several approaches to confidence intervals for an error rate have been proposed. Here we evaluate six of these methods. To complete this evaluation, we simulate data from a wide variety of parameter values. This data are simulated via a correlated binary distribution. We then determine how well these methods do at what they say they do: capturing the parameter inside the confidence interval. In addition, the average widths of the various confidence intervals are recorded for each set of parameters. The complete results of this simulation are presented graphically for easy comparison. We conclude by making a recommendation regarding which method performs best.

The Mesa Arizona Pupil Tracking System

NASA Technical Reports Server (NTRS)

Wright, D. L.

1973-01-01

A computer-based Pupil Tracking/Teacher Monitoring System was designed for Mesa Public Schools, Mesa, Arizona. The established objectives of the system were to: (1) facilitate the economical collection and storage of student performance data necessary to objectively evaluate the relative effectiveness of teachers, instructional methods, materials, and applied concepts; and (2) identify, on a daily basis, those students requiring special attention in specific subject areas. The system encompasses computer hardware/software and integrated curricula progression/administration devices. It provides daily evaluation and monitoring of performance as students progress at class or individualized rates. In the process, it notifies the student and collects information necessary to validate or invalidate subject presentation devices, methods, materials, and measurement devices in terms of direct benefit to the students. The system utilizes a small-scale computer (e.g., IBM 1130) to assure low-cost replicability, and may be used for many subjects of instruction.

Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

NASA Technical Reports Server (NTRS)

Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

2016-01-01

Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

Low-temperature phase transitions in a soluble oligoacene and their effect on device performance and stability

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

Ward, J. W.; Goetz, K. P.; Obaid, A.

The use of organic semiconductors in high-performance organic field-effect transistors requires a thorough understanding of the effects that processing conditions, thermal, and bias-stress history have on device operation. Here, we evaluate the temperature dependence of the electrical properties of transistors fabricated with 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene, a material that has attracted much attention recently due to its exceptional electrical properties. We have discovered a phase transition at T = 205 K and discuss its implications on device performance and stability. We examined the impact of this low-temperature phase transition on the thermodynamic, electrical, and structural properties of both single crystals and thin films of this material.more » Our results show that while the changes to the crystal structure are reversible, the induced thermal stress yields irreversible degradation of the devices.« less

40 CFR 63.8005 - What requirements apply to my process vessels?

Code of Federal Regulations, 2010 CFR

2010-07-01

... condensers, as defined in § 63.1251, are not considered to be control devices for process vessels. (d... 1 to this subpart, you must conduct the performance test or design evaluation under conditions as specified in § 63.7(e)(1), except that the performance test or design evaluation must be conducted under...

RIGHT VENTRICULAR UNLOADING AND RESPIRATORY SUPPORT WITH A WEARABLE ARTIFICIAL PUMP-LUNG (APL) IN AN OVINE MODEL

PubMed Central

Liu, Yang; Sanchez, Pablo G; Wei, Xufeng; Li, Tieluo; Watkins, Amelia C; Li, Shu-ying; Griffith, Bartley P; Wu, Zhongjun J

2014-01-01

Background Device availability of mechanical circulatory or respiratory support to the right heart has been limited. The purpose of this study was to investigate the effect of right heart unloading and respiratory support with a wearable integrated artificial pump-lung (APL). Methods The APL device was placed surgically between the right atrium and pulmonary artery in seven sheep. Anticoagulation was performed with heparin infusion. Its ability to unload the right ventricle (RV) was investigated by echocardiograms and right heart catheterization at different bypass flow rates. Hemodynamics and Echo data were evaluated. The device flow and gas transfer rates were also measured at different device speeds. Results Hemodynamics remained stable during APL support. There was no significant change in systemic blood pressure and cardiac index. Central venous pressure, RV pressure, RV end-diastolic dimension and RV ejection fraction were significant decreased when APL device flow rate approached 2 L/min. The linear regression showed significant correlative trends between the hemodynamic and cardiac indices and the device speed. The oxygen transfer rate increased with the device speed. The oxygen saturation from APL outlet was fully saturated (>95%) during the support. The impact of the APL support on blood elements (plasma free hemoglobin and platelet activation) was minimal. Conclusion The APL device support significantly unloaded the right ventricle with increasing device speed. The APL device provided stable hemodynamic and respiratory support in terms of blood flow and oxygen transfer. The right heart unloading performance of this wearable device need to be evaluated in the animal model with right heart failure for a long term support. PMID:24746636

Toward optimizing patient-specific IMRT QA techniques in the accurate detection of dosimetrically acceptable and unacceptable patient plans

PubMed Central

McKenzie, Elizabeth M.; Balter, Peter A.; Stingo, Francesco C.; Jones, Jimmy; Followill, David S.; Kry, Stephen F.

2014-01-01

Purpose: The authors investigated the performance of several patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA) dosimeters in terms of their ability to correctly identify dosimetrically acceptable and unacceptable IMRT patient plans, as determined by an in-house-designed multiple ion chamber phantom used as the gold standard. A further goal was to examine optimal threshold criteria that were consistent and based on the same criteria among the various dosimeters. Methods: The authors used receiver operating characteristic (ROC) curves to determine the sensitivity and specificity of (1) a 2D diode array undergoing anterior irradiation with field-by-field evaluation, (2) a 2D diode array undergoing anterior irradiation with composite evaluation, (3) a 2D diode array using planned irradiation angles with composite evaluation, (4) a helical diode array, (5) radiographic film, and (6) an ion chamber. This was done with a variety of evaluation criteria for a set of 15 dosimetrically unacceptable and 9 acceptable clinical IMRT patient plans, where acceptability was defined on the basis of multiple ion chamber measurements using independent ion chambers and a phantom. The area under the curve (AUC) on the ROC curves was used to compare dosimeter performance across all thresholds. Optimal threshold values were obtained from the ROC curves while incorporating considerations for cost and prevalence of unacceptable plans. Results: Using common clinical acceptance thresholds, most devices performed very poorly in terms of identifying unacceptable plans. Grouping the detector performance based on AUC showed two significantly different groups. The ion chamber, radiographic film, helical diode array, and anterior-delivered composite 2D diode array were in the better-performing group, whereas the anterior-delivered field-by-field and planned gantry angle delivery using the 2D diode array performed less well. Additionally, based on the AUCs, there was no significant difference in the performance of any device between gamma criteria of 2%/2 mm, 3%/3 mm, and 5%/3 mm. Finally, optimal cutoffs (e.g., percent of pixels passing gamma) were determined for each device and while clinical practice commonly uses a threshold of 90% of pixels passing for most cases, these results showed variability in the optimal cutoff among devices. Conclusions: IMRT QA devices have differences in their ability to accurately detect dosimetrically acceptable and unacceptable plans. Field-by-field analysis with a MapCheck device and use of the MapCheck with a MapPhan phantom while delivering at planned rotational gantry angles resulted in a significantly poorer ability to accurately sort acceptable and unacceptable plans compared with the other techniques examined. Patient-specific IMRT QA techniques in general should be thoroughly evaluated for their ability to correctly differentiate acceptable and unacceptable plans. Additionally, optimal agreement thresholds should be identified and used as common clinical thresholds typically worked very poorly to identify unacceptable plans. PMID:25471949

Toward optimizing patient-specific IMRT QA techniques in the accurate detection of dosimetrically acceptable and unacceptable patient plans.

PubMed

McKenzie, Elizabeth M; Balter, Peter A; Stingo, Francesco C; Jones, Jimmy; Followill, David S; Kry, Stephen F

2014-12-01

The authors investigated the performance of several patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA) dosimeters in terms of their ability to correctly identify dosimetrically acceptable and unacceptable IMRT patient plans, as determined by an in-house-designed multiple ion chamber phantom used as the gold standard. A further goal was to examine optimal threshold criteria that were consistent and based on the same criteria among the various dosimeters. The authors used receiver operating characteristic (ROC) curves to determine the sensitivity and specificity of (1) a 2D diode array undergoing anterior irradiation with field-by-field evaluation, (2) a 2D diode array undergoing anterior irradiation with composite evaluation, (3) a 2D diode array using planned irradiation angles with composite evaluation, (4) a helical diode array, (5) radiographic film, and (6) an ion chamber. This was done with a variety of evaluation criteria for a set of 15 dosimetrically unacceptable and 9 acceptable clinical IMRT patient plans, where acceptability was defined on the basis of multiple ion chamber measurements using independent ion chambers and a phantom. The area under the curve (AUC) on the ROC curves was used to compare dosimeter performance across all thresholds. Optimal threshold values were obtained from the ROC curves while incorporating considerations for cost and prevalence of unacceptable plans. Using common clinical acceptance thresholds, most devices performed very poorly in terms of identifying unacceptable plans. Grouping the detector performance based on AUC showed two significantly different groups. The ion chamber, radiographic film, helical diode array, and anterior-delivered composite 2D diode array were in the better-performing group, whereas the anterior-delivered field-by-field and planned gantry angle delivery using the 2D diode array performed less well. Additionally, based on the AUCs, there was no significant difference in the performance of any device between gamma criteria of 2%/2 mm, 3%/3 mm, and 5%/3 mm. Finally, optimal cutoffs (e.g., percent of pixels passing gamma) were determined for each device and while clinical practice commonly uses a threshold of 90% of pixels passing for most cases, these results showed variability in the optimal cutoff among devices. IMRT QA devices have differences in their ability to accurately detect dosimetrically acceptable and unacceptable plans. Field-by-field analysis with a MapCheck device and use of the MapCheck with a MapPhan phantom while delivering at planned rotational gantry angles resulted in a significantly poorer ability to accurately sort acceptable and unacceptable plans compared with the other techniques examined. Patient-specific IMRT QA techniques in general should be thoroughly evaluated for their ability to correctly differentiate acceptable and unacceptable plans. Additionally, optimal agreement thresholds should be identified and used as common clinical thresholds typically worked very poorly to identify unacceptable plans.

Application Performance Analysis and Efficient Execution on Systems with multi-core CPUs, GPUs and MICs: A Case Study with Microscopy Image Analysis

PubMed Central

Teodoro, George; Kurc, Tahsin; Andrade, Guilherme; Kong, Jun; Ferreira, Renato; Saltz, Joel

2015-01-01

We carry out a comparative performance study of multi-core CPUs, GPUs and Intel Xeon Phi (Many Integrated Core-MIC) with a microscopy image analysis application. We experimentally evaluate the performance of computing devices on core operations of the application. We correlate the observed performance with the characteristics of computing devices and data access patterns, computation complexities, and parallelization forms of the operations. The results show a significant variability in the performance of operations with respect to the device used. The performances of operations with regular data access are comparable or sometimes better on a MIC than that on a GPU. GPUs are more efficient than MICs for operations that access data irregularly, because of the lower bandwidth of the MIC for random data accesses. We propose new performance-aware scheduling strategies that consider variabilities in operation speedups. Our scheduling strategies significantly improve application performance compared to classic strategies in hybrid configurations. PMID:28239253

Performance evaluation of continuity of care records (CCRs): parsing models in a mobile health management system.

PubMed

Chen, Hung-Ming; Liou, Yong-Zan

2014-10-01

In a mobile health management system, mobile devices act as the application hosting devices for personal health records (PHRs) and the healthcare servers construct to exchange and analyze PHRs. One of the most popular PHR standards is continuity of care record (CCR). The CCR is expressed in XML formats. However, parsing is an expensive operation that can degrade XML processing performance. Hence, the objective of this study was to identify different operational and performance characteristics for those CCR parsing models including the XML DOM parser, the SAX parser, the PULL parser, and the JSON parser with regard to JSON data converted from XML-based CCR. Thus, developers can make sensible choices for their target PHR applications to parse CCRs when using mobile devices or servers with different system resources. Furthermore, the simulation experiments of four case studies are conducted to compare the parsing performance on Android mobile devices and the server with large quantities of CCR data.

Performance Evaluation of an Automotive-Grade, High Speed Gate Driver for SiC FETs, Type UCC27531, Over a Wide Temperature Range

NASA Technical Reports Server (NTRS)

Boomer, Kristen; Hammoud, Ahmad

2015-01-01

Silicon carbide (SiC) devices are becoming widely used in electronic power circuits as replacement for conventional silicon parts due to their attractive properties that include low on-state resistance, high temperature tolerance, and high frequency operation. These attributes have a significant impact by reducing system weight, saving board space, and conserving power. In this work, the performance of an automotive-grade high speed gate driver with potential use in controlling SiC FETs (field-Effect Transistors) in converters or motor control applications was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to assess performance and to determine suitability of this device for use in space exploration missions under extreme temperature conditions.

Single event induced transients in I/O devices - A characterization

NASA Technical Reports Server (NTRS)

Newberry, D. M.; Kaye, D. H.; Soli, G. A.

1990-01-01

The results of single-event upset (SEU) testing performed to evaluate the parametric transients, i.e., amplitude and duration, in several I/O devices, and the impact of these transients are discussed. The failure rate of these devices is dependent on the susceptibility of interconnected devices to the resulting transient change in the output of the I/O device. This failure rate, which is a function of the susceptibility of the interconnected device as well as the SEU response of the I/O device itself, may be significantly different from an upset rate calculated without taking these factors into account. The impact at the system level is discussed by way of an example.

Situation-Dependent Medical Device Risk Estimation: Design and Evaluation of an Equipment Management Center For Vendor-Independent Integrated Operating Rooms.

PubMed

Maktabi, Marianne; Neumuth, Thomas

2017-12-22

The complexity of surgical interventions and the number of technologies involved are constantly rising. Hospital staff has to learn how to handle new medical devices efficiently. However, if medical device-related incidents occur, the patient treatment is delayed. Patient safety could therefore be supported by an optimized assistance system that helps improve the management of technical equipment by nonmedical hospital staff. We developed a system for the optimal monitoring of networked medical device activity and maintenance requirements, which works in conjunction with a vendor-independent integrated operating room and an accurate surgical intervention Time And Resource Management System. An integrated situation-dependent risk assessment system gives the medical engineers optimal awareness of the medical devices in the operating room. A qualitative and quantitative survey among ten medical engineers from three different hospitals was performed to evaluate the approach. A series of 25 questions was used to evaluate various aspects of our system as well as the system currently used. Moreover, the respondents were asked to perform five tasks related to system supervision and incident handling. Our system received a very positive feedback. The evaluation studies showed that the integration of information, the structured presentation of information, and the assistance modules provide valuable support to medical engineers. An automated operating room monitoring system with an integrated risk assessment and Time And Resource Management System module is a new way to assist the staff being outside of a vendor-independent integrated operating room, who are nevertheless involved in processes in the operating room.

TECHNOLOGICAL INNOVATION IN NEUROSURGERY: A QUANTITATIVE STUDY

PubMed Central

Marcus, Hani J; Hughes-Hallett, Archie; Kwasnicki, Richard M; Darzi, Ara; Yang, Guang-Zhong; Nandi, Dipankar

2015-01-01

Object Technological innovation within healthcare may be defined as the introduction of a new technology that initiates a change in clinical practice. Neurosurgery is a particularly technologically intensive surgical discipline, and new technologies have preceded many of the major advances in operative neurosurgical technique. The aim of the present study was to quantitatively evaluate technological innovation in neurosurgery using patents and peer-reviewed publications as metrics of technology development and clinical translation respectively. Methods A patent database was searched between 1960 and 2010 using the search terms “neurosurgeon” OR “neurosurgical” OR “neurosurgery”. The top 50 performing patent codes were then grouped into technology clusters. Patent and publication growth curves were then generated for these technology clusters. A top performing technology cluster was then selected as an exemplar for more detailed analysis of individual patents. Results In all, 11,672 patents and 208,203 publications relating to neurosurgery were identified. The top performing technology clusters over the 50 years were: image guidance devices, clinical neurophysiology devices, neuromodulation devices, operating microscopes and endoscopes. Image guidance and neuromodulation devices demonstrated a highly correlated rapid rise in patents and publications, suggesting they are areas of technology expansion. In-depth analysis of neuromodulation patents revealed that the majority of high performing patents were related to Deep Brain Stimulation (DBS). Conclusions Patent and publication data may be used to quantitatively evaluate technological innovation in neurosurgery. PMID:25699414

On the tip of the tongue: learning typing and pointing with an intra-oral computer interface.

PubMed

Caltenco, Héctor A; Breidegard, Björn; Struijk, Lotte N S Andreasen

2014-07-01

To evaluate typing and pointing performance and improvement over time of four able-bodied participants using an intra-oral tongue-computer interface for computer control. A physically disabled individual may lack the ability to efficiently control standard computer input devices. There have been several efforts to produce and evaluate interfaces that provide individuals with physical disabilities the possibility to control personal computers. Training with the intra-oral tongue-computer interface was performed by playing games over 18 sessions. Skill improvement was measured through typing and pointing exercises at the end of each training session. Typing throughput improved from averages of 2.36 to 5.43 correct words per minute. Pointing throughput improved from averages of 0.47 to 0.85 bits/s. Target tracking performance, measured as relative time on target, improved from averages of 36% to 47%. Path following throughput improved from averages of 0.31 to 0.83 bits/s and decreased to 0.53 bits/s with more difficult tasks. Learning curves support the notion that the tongue can rapidly learn novel motor tasks. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, which makes the tongue a feasible input organ for computer control. Intra-oral computer interfaces could provide individuals with severe upper-limb mobility impairments the opportunity to control computers and automatic equipment. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, but does not cause fatigue easily and might be invisible to other people, which is highly prioritized by assistive device users. Combination of visual and auditory feedback is vital for a good performance of an intra-oral computer interface and helps to reduce involuntary or erroneous activations.

In vivo evaluation of zirconia ceramic in the DexAide right ventricular assist device journal bearing.

PubMed

Saeed, Diyar; Shalli, Shanaz; Fumoto, Hideyuki; Ootaki, Yoshio; Horai, Tetsuya; Anzai, Tomohiro; Zahr, Roula; Horvath, David J; Massiello, Alex L; Chen, Ji-Feng; Dessoffy, Raymond; Catanese, Jacquelyn; Benefit, Stephen; Golding, Leonard A R; Fukamachi, Kiyotaka

2010-06-01

Zirconia is a ceramic with material properties ideal for journal bearing applications. The purpose of this study was to evaluate the use of zirconium oxide (zirconia) as a blood journal bearing material in the DexAide right ventricular assist device. Zirconia ceramic was used instead of titanium to manufacture the DexAide stator housing without changing the stator geometry or the remaining pump hardware components. Pump hydraulic performance, journal bearing reliability, biocompatibility, and motor efficiency data of the zirconia stator were evaluated in six chronic bovine experiments for 14-91 days and compared with data from chronic experiments using the titanium stator. Pump performance data including average in vivo pump flows and speeds using a zirconia stator showed no statistically significant difference to the average values for 16 prior titanium stator in vivo studies, with the exception of a 19% reduction in power consumption. Indices of hemolysis were comparable for both stator types. Results of coagulation assays and platelet aggregation tests for the zirconia stator implants showed no device-induced increase in platelet activation. Postexplant evaluation of the zirconia journal bearing surfaces showed no biologic deposition in any of the implants. In conclusion, zirconia ceramic can be used as a hemocompatible material to improve motor efficiency while maintaining hydraulic performance in a blood journal bearing application.

40 CFR 610.63 - Performance tests.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Performance tests. 610.63 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Special Test Procedures § 610.63 Performance tests... 0 to 60 mph acceleration tests (at normal ambient temperatures) on the baseline vehicle...

40 CFR 610.63 - Performance tests.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Performance tests. 610.63 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Special Test Procedures § 610.63 Performance tests... 0 to 60 mph acceleration tests (at normal ambient temperatures) on the baseline vehicle...

40 CFR 610.63 - Performance tests.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Performance tests. 610.63 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Special Test Procedures § 610.63 Performance tests... 0 to 60 mph acceleration tests (at normal ambient temperatures) on the baseline vehicle...

40 CFR 610.63 - Performance tests.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Performance tests. 610.63 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Special Test Procedures § 610.63 Performance tests... 0 to 60 mph acceleration tests (at normal ambient temperatures) on the baseline vehicle...

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

Holmes, J.P.; Maxwell, R.L.; Wright, L.J.

A biometric identification device is an automatic device that can verify a person's identity from a measurement of a physical feature or repeatable action of the individual. A reference measurement of the biometric is obtained when the individual is enrolled on the device. Subsequent verifications are made by comparing the submitted biometric feature against the reference sample. Sandia Laboratories has been evaluating the relative performance of several identity verifiers, using volunteer test subjects. Sandia testing methods and results are discussed.

Potential of a suite of robot/computer-assisted motivating systems for personalized, home-based, stroke rehabilitation

PubMed Central

Johnson, Michelle J; Feng, Xin; Johnson, Laura M; Winters, Jack M

2007-01-01

Background There is a need to improve semi-autonomous stroke therapy in home environments often characterized by low supervision of clinical experts and low extrinsic motivation. Our distributed device approach to this problem consists of an integrated suite of low-cost robotic/computer-assistive technologies driven by a novel universal access software framework called UniTherapy. Our design strategy for personalizing the therapy, providing extrinsic motivation and outcome assessment is presented and evaluated. Methods Three studies were conducted to evaluate the potential of the suite. A conventional force-reflecting joystick, a modified joystick therapy platform (TheraJoy), and a steering wheel platform (TheraDrive) were tested separately with the UniTherapy software. Stroke subjects with hemiparesis and able-bodied subjects completed tracking activities with the devices in different positions. We quantify motor performance across subject groups and across device platforms and muscle activation across devices at two positions in the arm workspace. Results Trends in the assessment metrics were consistent across devices with able-bodied and high functioning strokes subjects being significantly more accurate and quicker in their motor performance than low functioning subjects. Muscle activation patterns were different for shoulder and elbow across different devices and locations. Conclusion The Robot/CAMR suite has potential for stroke rehabilitation. By manipulating hardware and software variables, we can create personalized therapy environments that engage patients, address their therapy need, and track their progress. A larger longitudinal study is still needed to evaluate these systems in under-supervised environments such as the home. PMID:17331243

A TiAlCu Metallization for ` n' Type CoSb_x Skutterudites with Improved Performance for High-Temperature Energy Harvesting Applications

NASA Astrophysics Data System (ADS)

Rao, Ashwin; Bosak, Gregg; Joshi, Binay; Keane, Jennifer; Nally, Luke; Peng, Adam; Perera, Susanthri; Waring, Alfred; Poudel, Bed

2017-04-01

The choice of the appropriate metallizing layer for high-temperature thermoelectric (TE) materials is a tricky task and poses varied challenges to researchers. In this work, a n type TiAl metallizing layer (90% Ti with 10% Al by weight with a copper foil) is proposed for a Yb_{0.2}Co4Sb_{12} skutterudite (SK) TE material coupled with a standard ` p type' SK base of Nd_{0.45}Ce_{0.45}Fe_{3.5}Co_{0.5}Sb_{12} with a 60:12:28% Fe:Ni:Cr metallizing layer. The n type and p type nanostructured SK powders are sintered at high temperatures and pressures in a DC hot press from which a TE device is assembled using diced, polished and property characterized TE legs (high figure of merit zT of 1.4 for n type and 1.2 for p type, respectively). The device is evaluated for functional degradation with repeated cycling to 500°C hot side (HS) and 50°C cold side (CS) temperatures in a specially designed high-vacuum test rig with key TE properties like peak power, open circuit voltage, and material internal resistance continuously recorded over each cycle. The device shows stable performance with <7% drop in TE harvested power over 2500 thermal cycles. With the industry benchmark for evaluating TE device performance being around 1000 thermal cycles (<10% drop in TE power over time), the study indicates stable performance of the n type TiAl metallizing layer over the device lifetime.

Poor chest compression quality with mechanical compressions in simulated cardiopulmonary resuscitation: a randomized, cross-over manikin study.

PubMed

Blomberg, Hans; Gedeborg, Rolf; Berglund, Lars; Karlsten, Rolf; Johansson, Jakob

2011-10-01

Mechanical chest compression devices are being implemented as an aid in cardiopulmonary resuscitation (CPR), despite lack of evidence of improved outcome. This manikin study evaluates the CPR-performance of ambulance crews, who had a mechanical chest compression device implemented in their routine clinical practice 8 months previously. The objectives were to evaluate time to first defibrillation, no-flow time, and estimate the quality of compressions. The performance of 21 ambulance crews (ambulance nurse and emergency medical technician) with the authorization to perform advanced life support was studied in an experimental, randomized cross-over study in a manikin setup. Each crew performed two identical CPR scenarios, with and without the aid of the mechanical compression device LUCAS. A computerized manikin was used for data sampling. There were no substantial differences in time to first defibrillation or no-flow time until first defibrillation. However, the fraction of adequate compressions in relation to total compressions was remarkably low in LUCAS-CPR (58%) compared to manual CPR (88%) (95% confidence interval for the difference: 13-50%). Only 12 out of the 21 ambulance crews (57%) applied the mandatory stabilization strap on the LUCAS device. The use of a mechanical compression aid was not associated with substantial differences in time to first defibrillation or no-flow time in the early phase of CPR. However, constant but poor chest compressions due to failure in recognizing and correcting a malposition of the device may counteract a potential benefit of mechanical chest compressions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Characterization of Vertical Impact Device Acceleration Pulses Using Parametric Assessment: Phase II Accelerated Free-Fall

DTIC Science & Technology

2016-04-30

support contractor , Infoscitex, conducted a series of tests to identify the performance capabilities of the Vertical Impact Device (VID). The VID is a...C. Table 3. AFD Evaluation with Red IMPAC Programmer: Data Summary Showing Means and Standard Deviations Test Cell Drop Ht . (in) Mean Peak

A Study of LoRa: Long Range & Low Power Networks for the Internet of Things

PubMed Central

Augustin, Aloÿs; Yi, Jiazi; Clausen, Thomas; Townsley, William Mark

2016-01-01

LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed. PMID:27618064

A Study of LoRa: Long Range & Low Power Networks for the Internet of Things.

PubMed

Augustin, Aloÿs; Yi, Jiazi; Clausen, Thomas; Townsley, William Mark

2016-09-09

LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed.

Low power, compact charge coupled device signal processing system

NASA Technical Reports Server (NTRS)

Bosshart, P. W.; Buss, D. D.; Eversole, W. L.; Hewes, C. R.; Mayer, D. J.

1980-01-01

A variety of charged coupled devices (CCDs) for performing programmable correlation for preprocessing environmental sensor data preparatory to its transmission to the ground were developed. A total of two separate ICs were developed and a third was evaluated. The first IC was a CCD chirp z transform IC capable of performing a 32 point DFT at frequencies to 1 MHz. All on chip circuitry operated as designed with the exception of the limited dynamic range caused by a fixed pattern noise due to interactions between the digital and analog circuits. The second IC developed was a 64 stage CCD analog/analog correlator for performing time domain correlation. Multiplier errors were found to be less than 1 percent at designed signal levels and less than 0.3 percent at the measured smaller levels. A prototype IC for performing time domain correlation was also evaluated.

Reproducibility of an objective four-choice canine vision testing technique that assesses vision at differing light intensities.

PubMed

Annear, Matthew J; Gornik, Kara R; Venturi, Francesca L; Hauptman, Joe G; Bartoe, Joshua T; Petersen-Jones, Simon M

2013-09-01

The increasing importance of canine retinal dystrophy models means accurate vision testing is needed. This study was performed to evaluate a four-choice vision testing technique for any difference in outcome measures with repeated evaluations of the same dogs.   Four 11-month-old RPE65-deficient dogs. Vision was evaluated using a previously described four-choice vision testing device. Four evaluations were performed at 2-week intervals. Vision was assessed at six different white light intensities (bright through dim), and each eye was evaluated separately. The ability to select the one of the four exit tunnels that was open at the far end was assessed ('choice of exit') and recorded as correct or incorrect first tunnel choice. 'Time to exit' the device was also recorded. Both outcomes were analyzed for significance using anova. We hypothesized that performance would improve with repeated testing (more correct choices and more rapid time to exit). 'Choice of exit' did not vary significantly between each evaluation (P = 0.12), in contrast 'time to exit' increased significantly (P = 0.012), and showed greater variability in dim light conditions. We found no evidence to support the hypothesis that either measure of outcome worsened with repeated testing; in fact, the 'time to exit' outcome worsened rather than improved. The 'choice of exit' gave consistent results between trials. These outcome data indicate the importance of including a choice-based assessment of vision in addition to measurement of device transit time. © 2012 American College of Veterinary Ophthalmologists.

Research: Testing of a Novel Portable Body Temperature Conditioner Using a Thermal Manikin.

PubMed

Heller, Daniel; Heller, Alex; Moujaes, Samir; Williams, Shelley J; Hoffmann, Ryan; Sarkisian, Paul; Khalili, Kaveh; Rockenfeller, Uwe; Browder, Timothy D; Kuhls, Deborah A; Fildes, John J

2016-01-01

A battery-operated active cooling/heating device was developed to maintain thermoregulation of trauma victims in austere environments while awaiting evacuation to a hospital for further treatment. The use of a thermal manikin was adopted for this study in order to simulate load testing and evaluate the performance of this novel portable active cooling/heating device for both continuous (external power source) and battery power. The performance of the portable body temperature conditioner (PBTC) was evaluated through cooling/heating fraction tests to analyze the heat transfer between a thermal manikin and circulating water blanket to show consistent performance while operating under battery power. For the cooling/heating fraction tests, the ambient temperature was set to 15°C ± 1°C (heating) and 30°C ± 1°C (cooling). The PBTC water temperature was set to 37°C for the heating mode tests and 15°C for the cooling mode tests. The results showed consistent performance of the PBTC in terms of cooling/heating capacity while operating under both continuous and battery power. The PBTC functioned as intended and shows promise as a portable warming/cooling device for operation in the field.

Evaluating average and atypical response in radiation effects simulations

NASA Astrophysics Data System (ADS)

Weller, R. A.; Sternberg, A. L.; Massengill, L. W.; Schrimpf, R. D.; Fleetwood, D. M.

2003-12-01

We examine the limits of performing single-event simulations using pre-averaged radiation events. Geant4 simulations show the necessity, for future devices, to supplement current methods with ensemble averaging of device-level responses to physically realistic radiation events. Initial Monte Carlo simulations have generated a significant number of extremal events in local energy deposition. These simulations strongly suggest that proton strikes of sufficient energy, even those that initiate purely electronic interactions, can initiate device response capable in principle of producing single event upset or microdose damage in highly scaled devices.

Nanomagnet Logic: Architectures, design, and benchmarking

NASA Astrophysics Data System (ADS)

Kurtz, Steven J.

Nanomagnet Logic (NML) is an emerging technology being studied as a possible replacement or supplementary device for Complimentary Metal-Oxide-Semiconductor (CMOS) Field-Effect Transistors (FET) by the year 2020. NML devices offer numerous potential advantages including: low energy operation, steady state non-volatility, radiation hardness and a clear path to fabrication and integration with CMOS. However, maintaining both low-energy operation and non-volatility while scaling from the device to the architectural level is non-trivial as (i) nearest neighbor interactions within NML circuits complicate the modeling of ensemble nanomagnet behavior and (ii) the energy intensive clock structures required for re-evaluation and NML's relatively high latency challenge its ability to offer system-level performance wins against other emerging nanotechnologies. Thus, further research efforts are required to model more complex circuits while also identifying circuit design techniques that balance low-energy operation with steady state non-volatility. In addition, further work is needed to design and model low-power on-chip clocks while simultaneously identifying application spaces where NML systems (including clock overhead) offer sufficient energy savings to merit their inclusion in future processors. This dissertation presents research advancing the understanding and modeling of NML at all levels including devices, circuits, and line clock structures while also benchmarking NML against both scaled CMOS and tunneling FETs (TFET) devices. This is accomplished through the development of design tools and methodologies for (i) quantifying both energy and stability in NML circuits and (ii) evaluating line-clocked NML system performance. The application of these newly developed tools improves the understanding of ideal design criteria (i.e., magnet size, clock wire geometry, etc.) for NML architectures. Finally, the system-level performance evaluation tool offers the ability to project what advancements are required for NML to realize performance improvements over scaled-CMOS hardware equivalents at the functional unit and/or application-level.

A generic approach for examining the effectiveness of traffic control devices in school zones.

PubMed

Zhao, Xiaohua; Li, Jiahui; Ding, Han; Zhang, Guohui; Rong, Jian

2015-09-01

The effectiveness and performance of traffic control devices in school zones have been impacted significantly by many factors, such as driver behavioral attributes, roadway geometric features, environmental characteristics, weather and visibility conditions, region-wide traffic regulations and policies, control modes, etc. When deploying traffic control devices in school zones, efforts are needed to clarify: (1) whether traffic control device installation is warranted; and (2) whether other device effectively complements this traffic control device and strengthens its effectiveness. In this study, a generic approach is developed to examine and evaluate the effectiveness of various traffic control devices deployed in school zones through driving simulator-based experiments. A Traffic Control Device Selection Model (TCDSM) is developed and two representative school zones are selected as the testbed in Beijing for driving simulation implementation to enhance its applicability. Statistical analyses are conducted to extract the knowledge from test data recorded by a driving simulator. Multiple measures of effectiveness (MOEs) are developed and adopted including average speed, relative speed difference, and standard deviation of acceleration for traffic control device performance quantification. The experimental tests and analysis results reveal that the appropriateness of the installation of certain traffic control devices can be statistically verified by TCDSM. The proposed approach provides a generic framework to assess traffic control device performance in school zones including experiment design, statistical formulation, data analysis, simulation model implementation, data interpretation, and recommendation development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Retrospective Analysis of Esophageal Heat Transfer for Active Temperature Management in Post-cardiac Arrest, Refractory Fever, and Burn Patients.

PubMed

Naiman, Melissa; Markota, Andrej; Hegazy, Ahmed; Dingley, John; Kulstad, Erik

2018-03-01

Core temperature management is an important aspect of critical care; preventing unintentional hypothermia, reducing fever, and inducing therapeutic hypothermia when appropriate are each tied to positive health outcomes. The purpose of this study is to evaluate the performance of a new temperature management device that uses the esophageal environment to conduct heat transfer. De-identified patient data were aggregated from three clinical sites where an esophageal heat transfer device (EHTD) was used to provide temperature management. The device was evaluated against temperature management guidelines and best practice recommendations, including performance during induction, maintenance, and cessation of therapy. Across all active cooling protocols, the average time-to-target was 2.37 h and the average maintenance phase was 22.4 h. Patients spent 94.9% of the maintenance phase within ±1.0°C and 67.2% within ±0.5°C (574 and 407 measurements, respectively, out of 605 total). For warming protocols, all of the patient temperature readings remained above 36°C throughout the surgical procedure (average 4.66 h). The esophageal heat transfer device met performance expectations across a range of temperature management applications in intensive care and burn units. Patients met and maintained temperature goals without any reported adverse events.

Hand controller commonality evaluation process

NASA Technical Reports Server (NTRS)

Stuart, Mark A.; Bierschwale, John M.; Wilmington, Robert P.; Adam, Susan C.; Diaz, Manuel F.; Jensen, Dean G.

1990-01-01

A hand controller evaluation process has been developed to determine the appropriate hand controller configurations for supporting remotely controlled devices. These devices include remote manipulator systems (RMS), dexterous robots, and remotely-piloted free flyers. Standard interfaces were developed to evaluate six different hand controllers in three test facilities including dynamic computer simulations, kinematic computer simulations, and physical simulations. The hand controllers under consideration were six degree-of-freedom (DOF) position and rate minimaster and joystick controllers, and three-DOF rate controllers. Task performance data, subjective comments, and anthropometric data obtained during tests were used for controller configuration recommendations to the SSF Program.

Constructing the informatics and information technology foundations of a medical device evaluation system: a report from the FDA unique device identifier demonstration.

PubMed

Drozda, Joseph P; Roach, James; Forsyth, Thomas; Helmering, Paul; Dummitt, Benjamin; Tcheng, James E

2018-02-01

The US Food and Drug Administration (FDA) has recognized the need to improve the tracking of medical device safety and performance, with implementation of Unique Device Identifiers (UDIs) in electronic health information as a key strategy. The FDA funded a demonstration by Mercy Health wherein prototype UDIs were incorporated into its electronic information systems. This report describes the demonstration's informatics architecture. Prototype UDIs for coronary stents were created and implemented across a series of information systems, resulting in UDI-associated data flow from manufacture through point of use to long-term follow-up, with barcode scanning linking clinical data with UDI-associated device attributes. A reference database containing device attributes and the UDI Research and Surveillance Database (UDIR) containing the linked clinical and device information were created, enabling longitudinal assessment of device performance. The demonstration included many stakeholders: multiple Mercy departments, manufacturers, health system partners, the FDA, professional societies, the National Cardiovascular Data Registry, and information system vendors. The resulting system of systems is described in detail, including entities, functions, linkage between the UDIR and proprietary systems using UDIs as the index key, data flow, roles and responsibilities of actors, and the UDIR data model. The demonstration provided proof of concept that UDIs can be incorporated into provider and enterprise electronic information systems and used as the index key to combine device and clinical data in a database useful for device evaluation. Keys to success and challenges to achieving this goal were identified. Fundamental informatics principles were central to accomplishing the system of systems model. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Development of a high capacity bubble domain memory element and related epitaxial garnet materials for application in spacecraft data recorders. Item 2: The optimization of material-device parameters for application in bubble domain memory elements for spacecraft data recorders

NASA Technical Reports Server (NTRS)

Besser, P. J.

1976-01-01

Bubble domain materials and devices are discussed. One of the materials development goals was a materials system suitable for operation of 16 micrometer period bubble domain devices at 150 kHz over the temperature range -10 C to +60 C. Several material compositions and hard bubble suppression techniques were characterized and the most promising candidates were evaluated in device structures. The technique of pulsed laser stroboscopic microscopy was used to characterize bubble dynamic properties and device performance at 150 kHz. Techniques for large area LPE film growth were developed as a separate task. Device studies included detector optimization, passive replicator design and test and on-chip bridge evaluation. As a technology demonstration an 8 chip memory cell was designed, tested and delivered. The memory elements used in the cell were 10 kilobit serial registers.

Fleet Evaluation and Factory Installation of Aerodynamic Heavy Duty Truck Trailers

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

Beck, Jason; Salari, Kambiz; Ortega, Jason

2013-09-30

The purpose of DE-EE0001552 was to develop and deploy a combination of trailer aerodynamic devices and low rolling resistance tires that reduce fuel consumption of a class 8 heavy duty tractor-trailer combination vehicle by 15%. There were 3 phases of the project: Phase 1 – Perform SAE Typed 2 track tests with multiple device combinations. Phase 2 – Conduct a fleet evaluation with selected device combination. Phase 3 – Develop the devices required to manufacture the aerodynamic trailer. All 3 phases have been completed. There is an abundance of available trailer devices on the market, and fleets and owner operatorsmore » have awareness of them and are purchasing them. The products developed in conjunction with this project are at least in their second round of refinement. The fleet test undertaken showed an improvement of 5.5 – 7.8% fuel economy with the devices (This does not include tire contribution).« less

A valid and reliable method to measure jump-specific training and competition load in elite volleyball players.

PubMed

Skazalski, C; Whiteley, R; Hansen, C; Bahr, R

2018-05-01

Use of a commercially available wearable device to monitor jump load with elite volleyball players has become common practice. The purpose of this study was to evaluate the validity and reliability of this device, the Vert, to count jumps and measure jump height with professional volleyball players. Jump count accuracy was determined by comparing jumps recorded by the device to jumps observed through systematic video analysis of three practice sessions and two league matches performed by a men's professional volleyball team. Jumps performed by 14 players were each coded for time and jump type and individually matched to device recorded jumps. Jump height validity of the device was examined against reference standards as participants performed countermovement jumps on a force plate and volleyball-specific jumps with a Vertec. The Vert device accurately counted 99.3% of the 3637 jumps performed during practice and match play. The device showed excellent jump height interdevice reliability for two devices placed in the same pouch during volleyball jumps (r = .99, 95% CI 0.98-0.99). The device had a minimum detectable change (MDC) of 9.7 cm and overestimated jump height by an average of 5.5 cm (95% CI 4.5-6.5) across all volleyball jumps. The Vert device demonstrates excellent accuracy counting volleyball-specific jumps during training and competition. While the device is not recommended to measure maximal jumping ability when precision is needed, it provides an acceptable measure of on-court jump height that can be used to monitor athlete jump load. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Simulation of Electric Potentials and Ion Motion in Planar Electrode Structures for Lossless Ion Manipulations (SLIM)

DOE PAGES

Garimella, Sandilya V. B; Ibrahim, Yehia M.; Webb, Ian K.; ...

2014-09-26

Here we report a conceptual study and computational evaluation of novel planar electrode Structures for Lossless Ion Manipulations (SLIM). Planar electrode SLIM devices were designed that allow for flexible ion confinement, transport and storage using a combination of RF and DC fields. Effective potentials can be generated that provide near ideal regions for confining ions in the presence of a gas. Ion trajectory simulations using SIMION 8.1 demonstrated the capability for lossless ion motion in these devices over a wide m/z range and a range of electric fields at low pressures (e.g. a few torr). More complex ion manipulations, e.g.more » turning ions by 90° and dynamically switching selected ion species into orthogonal channels, are also feasible. Lastly, the performance of SLIM devices at ~4 torr pressure for performing ion mobility based separations (IMS) is computationally evaluated and compared to initial experimental results, and both of which agree closely with experimental and theoretical IMS performance for a conventional drift tube design.« less

Monolithic Integration of Two-Dimensional Liquid Chromatography-Capillary Electrophoresis and Electrospray Ionization on a Microfluidic Device

PubMed Central

Chambers, Andrew G.; Mellors, J. Scott; Henley, W. Hampton; Ramsey, J. Michael

2011-01-01

A microfluidic device capable of two-dimensional reversed-phase liquid chromatography-capillary electrophoresis with integrated electrospray ionization (LC-CE-ESI) for mass spectrometry (MS)-based proteomic applications is described. Traditional instrumentation was used for the LC sample injection and delivery of the LC mobile phase. The glass microfabricated device incorporated a sample-trapping region and an LC channel packed with reversed-phase particles. Rapid electrokinetic injections of the LC effluent into the CE dimension were performed at a cross channel intersection. The CE separation channel terminated at a corner of the square device, which functioned as an integrated electrospray tip. In addition to LC-CE-ESI, this device was used for LC-ESI without any instrumental modifications. To evaluate the system, LC-MS and LC-CE-MS analysis of protein digests were performed and compared. PMID:21214194

Computational Investigation of the NASA Cascade Cyclonic Separation Device

NASA Technical Reports Server (NTRS)

Hoyt, Nathaniel C.; Kamotani, Yasuhiro; Kadambi, Jaikrishnan; McQuillen, John B.; Sankovic, John M.

2008-01-01

Devices designed to replace the absent buoyancy separation mechanism within a microgravity environment are of considerable interest to NASA as the functionality of many spacecraft systems are dependent on the proper sequestration of interpenetrating gas and liquid phases. Inasmuch, a full multifluid Euler-Euler computational fluid dynamics investigation has been undertaken to evaluate the performance characteristics of one such device, the Cascade Cyclonic Separator, across a full range of inlet volumetric quality with combined volumetric injection rates varying from 1 L/min to 20 L/min. These simulations have delimited the general modes of operation of this class of devices and have proven able to describe the complicated vortex structure and induced pressure gradients that arise. The computational work has furthermore been utilized to analyze design modifications that enhance the overall performance of these devices. The promising results indicate that proper CFD modeling may be successfully used as a tool for microgravity separator design.

Performance analysis of newly developed point-of-care hemoglobinometer (TrueHb) against an automated hematology analyzer (Sysmex XT 1800i) in terms of precision in hemoglobin measurement.

PubMed

Srivastava, A; Koul, V; Dwivedi, S N; Upadhyaya, A D; Ahuja, A; Saxena, R

2015-08-01

The aim of this study was to evaluate the performance of the newly developed handheld hemoglobinmeter (TrueHb) by comparing its performance against and an automated five-part hematology analyzer, Sysmex counter XT 1800i (Sysmex). Two hundred venous blood samples were subjected through their total hemoglobin evaluation on each device three times. The average of the three readings on each device was considered as their respective device values, that is, TrueHb values and Sysmex values. The two set of values were comparatively analyzed. The repeatability of the performance of TrueHb was also evaluated against Sysmex values. The scatter plot of TrueHb values and Sysmex values showed linear distribution with positive correlations (r = 0.99). The intraclass correlation (ICC) values between the two set of values was found to be 0.995. Regression coefficients through origin, β, was found to be 0.995, with 95% confidence intervals (CI) ranging between 0.9900 and 1.0000. The mean difference in Bland-Altman plots of TrueHb values against the Sysmex values was found to be -0.02, with limits of agreement between -0.777 and 0.732 g/dL. Statistical analysis suggested good repeatability in results of TrueHb, having a low mean CV of 2.22, against 4.44, that of Sysmex values, and 95% confidence interval of 1.99-2.44, against 3.85-5.03, that of Sysmex values. These results suggested a strong positive correlation between the two measurements devices. It is thus concluded that TrueHb is a good point-of-care testing tool for estimating hemoglobin. © 2014 John Wiley & Sons Ltd.

Video display engineering and optimization system

NASA Technical Reports Server (NTRS)

Larimer, James (Inventor)

1997-01-01

A video display engineering and optimization CAD simulation system for designing a LCD display integrates models of a display device circuit, electro-optics, surface geometry, and physiological optics to model the system performance of a display. This CAD system permits system performance and design trade-offs to be evaluated without constructing a physical prototype of the device. The systems includes a series of modules which permit analysis of design trade-offs in terms of their visual impact on a viewer looking at a display.

Development and evaluation of a new taxonomy of mobility-related assistive technology devices.

PubMed

Shoemaker, Laura L; Lenker, James A; Fuhrer, Marcus J; Jutai, Jeffrey W; Demers, Louise; DeRuyter, Frank

2010-10-01

This article reports on the development of a new taxonomy for mobility-related assistive technology devices. A prototype taxonomy was created based on the extant literature. Five mobility device experts were engaged in a modified Delphi process to evaluate and refine the taxonomy. Multiple iterations of expert feedback and revision yielded consensual agreement on the structure and terminology of a new mobility device taxonomy. The taxonomy uses a hierarchical framework to classify ambulation aids and wheeled mobility devices, including their key features that impact mobility. Five attributes of the new taxonomy differentiate it from previous mobility-related device classifications: (1) hierarchical structure, (2) primary device categories are grouped based on their intended mobility impact, (3) comprehensive inclusion of technical features, (4) a capacity to assimilate reimbursement codes, and (5) availability of a detailed glossary. The taxonomy is intended to support assistive technology outcomes research. The taxonomy will enable researchers to capture mobility-related assistive technology device interventions with precision and provide a common terminology that will allow comparisons among studies. The prominence of technical features within the new taxonomy will hopefully promote research that helps clinicians predict how devices will perform, thus aiding clinical decision making and supporting funding recommendations.

Comparative Evaluations of Randomly Selected Four Point-of-Care Glucometer Devices in Addis Ababa, Ethiopia.

PubMed

Wolde, Mistire; Tarekegn, Getahun; Kebede, Tedla

2018-05-01

Point-of-care glucometer (PoCG) devices play a significant role in self-monitoring of the blood sugar level, particularly in the follow-up of high blood sugar therapeutic response. The aim of this study was to evaluate blood glucose test results performed with four randomly selected glucometers on diabetes and control subjects versus standard wet chemistry (hexokinase) methods in Addis Ababa, Ethiopia. A prospective cross-sectional study was conducted on randomly selected 200 study participants (100 participants with diabetes and 100 healthy controls). Four randomly selected PoCG devices (CareSens N, DIAVUE Prudential, On Call Extra, i-QARE DS-W) were evaluated against hexokinase method and ISO 15197:2003 and ISO 15197:2013 standards. The minimum and maximum blood sugar values were recorded by CareSens N (21 mg/dl) and hexokinase method (498.8 mg/dl), respectively. The mean sugar values of all PoCG devices except On Call Extra showed significant differences compared with the reference hexokinase method. Meanwhile, all four PoCG devices had strong positive relationship (>80%) with the reference method (hexokinase). On the other hand, none of the four PoCG devices fulfilled the minimum accuracy measurement set by ISO 15197:2003 and ISO 15197:2013 standards. In addition, the linear regression analysis revealed that all four selected PoCG overestimated the glucose concentrations. The overall evaluation of the selected four PoCG measurements were poorly correlated with standard reference method. Therefore, before introducing PoCG devices to the market, there should be a standardized evaluation platform for validation. Further similar large-scale studies on other PoCG devices also need to be undertaken.

CFD Design and Analysis of a Passively Suspended Tesla Pump Left Ventricular Assist Device

PubMed Central

Medvitz, Richard B.; Boger, David A.; Izraelev, Valentin; Rosenberg, Gerson; Paterson, Eric G.

2012-01-01

This paper summarizes the use of computational fluid dynamics (CFD) to design a novelly suspended Tesla LVAD. Several design variants were analyzed to study the parameters affecting device performance. CFD was performed at pump speeds of 6500, 6750 and 7000 RPM and at flow rates varying from 3 to 7 liter-per-minute (LPM). The CFD showed that shortening the plates nearest the pump inlet reduced the separations formed beneath the upper plate leading edges and provided a more uniform flow distribution through the rotor gaps, both of which positively affected the device hydrodynamic performance. The final pump design was found to produce a head rise of 77 mmHg with a hydraulic efficiency of 16% at the design conditions of 6 LPM throughflow and a 6750 RPM rotation rate. To assess the device hemodynamics the strain rate fields were evaluated. The wall shear stresses demonstrated that the pump wall shear stresses were likely adequate to inhibit thrombus deposition. Finally, an integrated field hemolysis model was applied to the CFD results to assess the effects of design variation and operating conditions on the device hemolytic performance. PMID:21595722

Design of wearable health monitoring device

NASA Astrophysics Data System (ADS)

Devara, Kresna; Ramadhanty, Savira; Abuzairi, Tomy

2018-02-01

Wearable smart health monitoring devices have attracted considerable attention in both research community and industry. Some of the causes are the increasing healthcare costs, along with the growing technology. To address this demand, in this paper, design and evaluation of wearable health monitoring device integrated with smartphone were presented. This device was designed for patients in need of constant health monitoring. The performance of the proposed design has been tested by conducting measurement once in 2 minutes for 10 minutes to obtain heart rate and body temperature data. The comparation between data measured by the proposed device and that measured by the reference device yields only an average error of 1.45% for heart rate and 1.04% for body temperature.

Effects of input device and motion type on a cursor-positioning task.

PubMed

Yau, Yi-Jan; Hwang, Sheue-Ling; Chao, Chin-Jung

2008-02-01

Many studies have investigated the performance of using nonkey-board input devices under static situations, but few have considered the effects of motion type on manipulating these input devices. In this study comparison of 12 mens' performance using four input devices (three trackballs: currently used, trackman wheel, and erectly held trackballs, as well as a touch screen) under five motion types of static, heave, roll, pitch, and random movements was conducted. The input device and motion type significantly affected movement speed and accuracy, and their interaction significantly affected the movement speed. The touch screen was the fastest but the least accurate input device. The erectly held trackball was the slowest, whereas the error rate of the currently used trackball was the lowest. Impairments of the random motion on movement time and error rate were larger than those of other motion types. Considering objective and subjective evaluations, the trackman wheel and currently used trackball were more efficient in operation than the erectly held trackball and touch screen under the motion environments.

Remote gaming on resource-constrained devices

NASA Astrophysics Data System (ADS)

Reza, Waazim; Kalva, Hari; Kaufman, Richard

2010-08-01

Games have become important applications on mobile devices. A mobile gaming approach known as remote gaming is being developed to support games on low cost mobile devices. In the remote gaming approach, the responsibility of rendering a game and advancing the game play is put on remote servers instead of the resource constrained mobile devices. The games rendered on the servers are encoded as video and streamed to mobile devices. Mobile devices gather user input and stream the commands back to the servers to advance game play. With this solution, mobile devices with video playback and network connectivity can become game consoles. In this paper we present the design and development of such a system and evaluate the performance and design considerations to maximize the end user gaming experience.

Design and Evaluation of Novel Textile Wearable Systems for the Surveillance of Vital Signals.

PubMed

Trindade, Isabel G; Machado da Silva, José; Miguel, Rui; Pereira, Madalena; Lucas, José; Oliveira, Luís; Valentim, Bruno; Barreto, Jorge; Santos Silva, Manuel

2016-09-24

This article addresses the design, development, and evaluation of T-shirt prototypes that embed novel textile sensors for the capture of cardio and respiratory signals. The sensors are connected through textile interconnects to either an embedded custom-designed data acquisition and transmission unit or to snap fastener terminals for connection to external monitoring devices. The performance of the T-shirt prototype is evaluated in terms of signal-to-noise ratio amplitude and signal interference caused by baseline wander and motion artefacts, through laboratory tests with subjects in standing and walking conditions. Performance tests were also conducted in a hospital environment using a T-shirt prototype connected to a commercial three-channel Holter monitoring device. The textile sensors and interconnects were realized with the assistance of an industrial six-needle digital embroidery tool and their resistance to wear addressed with normalized tests of laundering and abrasion. The performance of these wearable systems is discussed, and pathways and methods for their optimization are highlighted.

Design and Evaluation of Novel Textile Wearable Systems for the Surveillance of Vital Signals

PubMed Central

Trindade, Isabel G.; Machado da Silva, José; Miguel, Rui; Pereira, Madalena; Lucas, José; Oliveira, Luís; Valentim, Bruno; Barreto, Jorge; Santos Silva, Manuel

2016-01-01

This article addresses the design, development, and evaluation of T-shirt prototypes that embed novel textile sensors for the capture of cardio and respiratory signals. The sensors are connected through textile interconnects to either an embedded custom-designed data acquisition and transmission unit or to snap fastener terminals for connection to external monitoring devices. The performance of the T-shirt prototype is evaluated in terms of signal-to-noise ratio amplitude and signal interference caused by baseline wander and motion artefacts, through laboratory tests with subjects in standing and walking conditions. Performance tests were also conducted in a hospital environment using a T-shirt prototype connected to a commercial three-channel Holter monitoring device. The textile sensors and interconnects were realized with the assistance of an industrial six-needle digital embroidery tool and their resistance to wear addressed with normalized tests of laundering and abrasion. The performance of these wearable systems is discussed, and pathways and methods for their optimization are highlighted. PMID:27669263

Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices

NASA Astrophysics Data System (ADS)

Gamzina, Diana

Diana Gamzina March 2016 Mechanical and Aerospace Engineering Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices Abstract A methodology for performing thermo-mechanical design and analysis of high frequency and high average power vacuum electron devices is presented. This methodology results in a "first-pass" engineering design directly ready for manufacturing. The methodology includes establishment of thermal and mechanical boundary conditions, evaluation of convective film heat transfer coefficients, identification of material options, evaluation of temperature and stress field distributions, assessment of microscale effects on the stress state of the material, and fatigue analysis. The feature size of vacuum electron devices operating in the high frequency regime of 100 GHz to 1 THz is comparable to the microstructure of the materials employed for their fabrication. As a result, the thermo-mechanical performance of a device is affected by the local material microstructure. Such multiscale effects on the stress state are considered in the range of scales from about 10 microns up to a few millimeters. The design and analysis methodology is demonstrated on three separate microwave devices: a 95 GHz 10 kW cw sheet beam klystron, a 263 GHz 50 W long pulse wide-bandwidth sheet beam travelling wave tube, and a 346 GHz 1 W cw backward wave oscillator.

A new exposure model to evaluate smoked illicit drugs in rodents: A study of crack cocaine.

PubMed

Hueza, Isis M; Ponce, Fernando; Garcia, Raphael C T; Marcourakis, Tânia; Yonamine, Maurício; Mantovani, Cínthia de C; Kirsten, Thiago B

2016-01-01

The use of smoked illicit drugs has spread dramatically, but few studies use proper devices to expose animals to inhalational abused drugs despite the availability of numerous smoking devices that mimic tobacco exposure in rodents. Therefore, the present study developed an inexpensive device to easily expose laboratory animals to smoked drugs. We used crack cocaine as the drug of abuse, and the cocaine plasma levels and the behaviors of animals intoxicated with the crack cocaine were evaluated to prove inhaled drug absorption and systemic activity. We developed an acrylic device with two chambers that were interconnected and separated by a hatch. Three doses of crack (100, 250, or 500 mg), which contained 63.7% cocaine, were burned in a pipe, and the rats were exposed to the smoke for 5 or 10 min (n=5/amount/period). Exposure to the 250-mg dose for 10 min achieved cocaine plasma levels that were similar to those of users (170 ng/mL). Behavioral evaluations were also performed to validate the methodology. Rats (n=10/group) for these evaluations were exposed to 250 mg of crack cocaine or air for 10 min, twice daily, for 28 consecutive days. Open-field evaluations were performed at three different periods throughout the experimental design. Exposed animals exhibited transient anorexia, increased motor activity, and shorter stays in central areas of the open field, which suggests reduced anxiety. Therefore, the developed model effectively exposed animals to crack cocaine, and this model may be useful for the investigation of other inhalational abused drugs. Copyright © 2015 Elsevier Inc. All rights reserved.

Proposal of an innovative benchmark for comparison of the performance of contactless digitizers

NASA Astrophysics Data System (ADS)

Iuliano, Luca; Minetola, Paolo; Salmi, Alessandro

2010-10-01

Thanks to the improving performances of 3D optical scanners, in terms of accuracy and repeatability, reverse engineering applications have extended from CAD model design or reconstruction to quality control. Today, contactless digitizing devices constitute a good alternative to coordinate measuring machines (CMMs) for the inspection of certain parts. The German guideline VDI/VDE 2634 is the only reference to evaluate whether 3D optical measuring systems comply with the declared or required performance specifications. Nevertheless it is difficult to compare the performance of different scanners referring to such a guideline. An adequate novel benchmark is proposed in this paper: focusing on the inspection of production tools (moulds), the innovative test piece was designed using common geometries and free-form surfaces. The reference part is intended to be employed for the evaluation of the performance of several contactless digitizing devices in computer-aided inspection, considering dimensional and geometrical tolerances as well as other quantitative and qualitative criteria.

A review of digital microfluidics as portable platforms for lab-on a-chip applications.

PubMed

Samiei, Ehsan; Tabrizian, Maryam; Hoorfar, Mina

2016-07-07

Following the development of microfluidic systems, there has been a high tendency towards developing lab-on-a-chip devices for biochemical applications. A great deal of effort has been devoted to improve and advance these devices with the goal of performing complete sets of biochemical assays on the device and possibly developing portable platforms for point of care applications. Among the different microfluidic systems used for such a purpose, digital microfluidics (DMF) shows high flexibility and capability of performing multiplex and parallel biochemical operations, and hence, has been considered as a suitable candidate for lab-on-a-chip applications. In this review, we discuss the most recent advances in the DMF platforms, and evaluate the feasibility of developing multifunctional packages for performing complete sets of processes of biochemical assays, particularly for point-of-care applications. The progress in the development of DMF systems is reviewed from eight different aspects, including device fabrication, basic fluidic operations, automation, manipulation of biological samples, advanced operations, detection, biological applications, and finally, packaging and portability of the DMF devices. Success in developing the lab-on-a-chip DMF devices will be concluded based on the advances achieved in each of these aspects.

Scientific evaluation and pricing of medical devices and associated procedures in France.

PubMed

Gilard, Martine; Debroucker, Frederique; Dubray, Claude; Allioux, Yves; Aper, Eliane; Barat-Leonhardt, Valérie; Brami, Michèle; Carbonneil, Cédric; Chartier-Kastler, Emmanuel; Coqueblin, Claire; Fare, Sandrine; Giri, Isabelle; Goehrs, Jean-Marie; Levesque, Karine; Maugendre, Philippe; Parquin, François; Sales, Jean-Patrick; Szwarcensztein, Karine

2013-01-01

Medical devices are many and various, ranging from tongue spatulas to implantable or invasive devices and imaging machines; their lifetimes are short, between 18 months and 5 years, due to incessant incremental innovation; and they are operator-dependent: in general, the clinical user performs a fitting procedure (hip implant or pacemaker), a therapeutic procedure using a non-implantable invasive device (arrhythmic site ablation probe, angioplasty balloon, extension spondyloplasty system, etc.) or follow-up of an active implanted device (long-term follow-up of an implanted cardiac defibrillator or of a deep brain stimulator in Parkinson's patients). A round-table held during the XXVIII(th) Giens Workshops meeting focused on the methodology of scientific evaluation of medical devices and the associated procedures with a view to their pricing and financing by the French National Health Insurance system. The working hypothesis was that the available data-set was sufficient for and compatible with scientific evaluation with clinical benefit. Post-registration studies, although contributing to the continuity of assessment, were not dealt with. Moreover, the focus was restricted to devices used in health establishments, where the association between devices and technical medical procedures is optimally representative. An update of the multiple regulatory protocols governing medical devices and procedures is provided. Issues more specifically related to procedures as such, to non-implantable devices and to innovative devices are then dealt with, and the proposals and discussion points raised at the round-table for each of these three areas are presented. © 2013 Société Française de Pharmacologie et de Thérapeutique.

Development of implant loading device for animal study about various loading protocol: a pilot study

PubMed Central

Yoon, Joon-Ho; Park, Young-Bum; Cho, Yuna; Kim, Chang-Sung; Choi, Seong-Ho; Moon, Hong-Seok; Lee, Keun-Woo

2012-01-01

PURPOSE The aims of this pilot study were to introduce implant loading devices designed for animal study and to evaluate the validity of the load transmission ability of the loading devices. MATERIALS AND METHODS Implant loading devices were specially designed and fabricated with two implant abutments and cast metal bars, and orthodontic expansion screw. In six Beagles, all premolars were extracted and two implants were placed in each side of the mandibles. The loading device was inserted two weeks after the implant placement. According to the loading protocol, the load was applied to the implants with different time and method,simulating early, progressive, and delayed loading. The implants were clinically evaluated and the loading devices were removed and replaced to the master cast, followed by stress-strain analysis. Descriptive statistics of remained strain (µε) was evaluated after repeating three cycles of the loading device activation. Statistic analysis was performed using nonparametric, independent t-test with 5% significance level and Friedman's test was also used for verification. RESULTS The loading devices were in good action. However, four implants in three Beagles showed loss of osseointegration. In stress-strain analysis, loading devices showed similar amount of increase in the remained strain after applying 1-unit load for three times. CONCLUSION Specialized design of the implant loading device was introduced. The loading device applied similar amount of loads near the implant after each 1-unit loading. However, the direction of the loads was not parallel to the long axis of the implants as predicted before the study. PMID:23236575

Comparative analysis for evaluating the traceability of interventional devices using blood vessel phantom models made of PVA-H or silicone.

PubMed

Yu, Chang-Ho; Kwon, Tae-Kyu; Park, Chan Hee; Ohta, Makoto; Kim, Sung Hoon

2015-01-01

In this paper, we investigated the parameters with effective traceability to assess the mechanical properties of interventional devices. In our evaluation system, a box-shaped poly (vinyl alcohol) hydrogel (PVA-H) and silicone were prepared with realistic geometry, and the measurement and evaluation of traceability were carried out on devices using load hand force. The phantom models had a total of five curve pathways to reach the aneurysm sac. Traceability depends on the performance of the interventional devices in order to pass through the curved part of the model simulation track. The traceability of the guide wire was found to be much better than that of the balloon and stent loading catheter, as it reached the aneurysm sac in both phantom models. Observation using the video record is another advantage of our system, because the high transparency of the materials with silicone and PVA-H can allow visualization of the inside of an artery.

Audio-based detection and evaluation of eating behavior using the smartwatch platform.

PubMed

Kalantarian, Haik; Sarrafzadeh, Majid

2015-10-01

In recent years, smartwatches have emerged as a viable platform for a variety of medical and health-related applications. In addition to the benefits of a stable hardware platform, these devices have a significant advantage over other wrist-worn devices, in that user acceptance of watches is higher than other custom hardware solutions. In this paper, we describe signal-processing techniques for identification of chews and swallows using a smartwatch device׳s built-in microphone. Moreover, we conduct a survey to evaluate the potential of the smartwatch as a platform for monitoring nutrition. The focus of this paper is to analyze the overall applicability of a smartwatch-based system for food-intake monitoring. Evaluation results confirm the efficacy of our technique; classification was performed between apple and potato chip bites, water swallows, talking, and ambient noise, with an F-measure of 94.5% based on 250 collected samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

Formaldehyde: a comparative evaluation of four monitoring methods

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

Coyne, L.B.; Cook, R.E.; Mann, J.R.

1985-10-01

The performances of four formaldehyde monitoring devices were compared in a series of laboratory and field experiments. The devices evaluated included the DuPont C-60 formaldehyde badge, the SKC impregnated charcoal tube, an impinger/polarographic method and the MDA Lion formaldemeter. The major evaluation parameters included: concentration range, effects of humidity, sample storage, air velocity, accuracy, precision, interferences from methanol, styrene, 1,3-butadiene, sulfur dioxide and dimethylamine. Based on favorable performances in the laboratory and field, each device was useful for monitoring formaldehyde in the industrial work environment; however, these devices were not evaluated for residential exposure assessment. The impinger/polarographic method had amore » sensitivity of 0.06 ppm, based on a 20-liter air sample volume, and accurately determined the short-term excursion limit (STEL). It was useful for area monitoring but was not very practical for time-weighted average (TWA) personal monitoring measurements. The DuPont badge had a sensitivity of 2.8 ppm-hr and accurately and simply determined TWA exposures. It was not sensitive enough to measure STEL exposures, however, and positive interferences resulted if 1,3-butadiene was present. The SKC impregnated charcoal tube measured both TWA and STEL concentrations and had a sensitivity of 0.06 ppm based on a 25-liter air sample volume. Lightweight and simple to use, the MDA Lion formaldemeter had a sensitivity of 0.2 ppm. It had the advantage of giving an instantaneous reading in the field; however, it must be used with caution because it responded to many interferences. The method of choice depended on the type of sampling required, field conditions encountered during sampling and an understanding of the limitations of each monitoring device.« less

A new adjustable parallel drill guide for internal fixation of femoral neck fracture: a developmental and experimental study.

PubMed

Yuenyongviwat, Varah; Tuntarattanapong, Pakjai; Tangtrakulwanich, Boonsin

2016-01-11

Internal fixation is one treatment for femoral neck fracture. Some devices and techniques reported improved accuracy and decreased fluoroscopic time. However, these are not widely used nowadays due to the lack of available special instruments and techniques. To improve the surgical procedure, the authors designed a new adjustable drill guide and tested the efficacy of the device. The authors developed a new adjustable drill guide for cannulated screw guide wire insertion for multiple screw fixation. Eight orthopaedic surgeons performed the experimental study to evaluate the efficacy of this device. Each surgeon performed guide wire insertion for multiple screw fixation in six synthetic femurs: three times with the new device and three times with the conventional technique. The fluoroscopic time, operative time and surgeon satisfaction were evaluated. In the operations with the new adjustable drill guide, the fluoroscopic and operative times were significantly lower than the operations with the conventional technique (p < 0.05). The mean score for the level of satisfaction of this device was also statistically significantly better (p = 0.02) than the conventional technique. The fluoroscopic and operative times with the new adjustable drill guide were reduced for multiple screw fixation of femoral neck fracture and the satisfaction of the surgeons was good.

A comparison between on-site immunoassay drug-testing devices and laboratory results.

PubMed

Grönholm, M; Lillsunde, P

2001-09-15

The aim with this study was to evaluate the accuracy of several on-site testing devices on the market. A part of this study is included in the European Union's (EU's) roadside testing assessment project (ROSITA). An other request for this kind of study came from the Finnish prison department in the Ministry of Justice. The evaluation was performed on both urine assays and oral fluid assays. The on-site test results were compared with laboratory results (gas chromatography-mass spectrometry (GC/MS)). The samples were tested on amphetamines (AMP), cannabinoids (THC), opiates (OPI) and cocaine metabolites (COC). Some of the tests also included a metamphetamine (MET) and a benzodiazepine (BZO) test. Both positive and negative samples were tested. A total of 800 persons and eight on-site devices for urine and two for oral fluid testing were included in this study. Good results were obtained for the urine on-site devices, with accuracies of 93-99% for amphetamines, 97-99% for cannabinoids, 94-98% for opiates and 90-98% for benzodiazepines. However, differences in the ease of performance and interpretation of test result were observed. It was possible to detect amphetamines and opiates in oral fluid by the used on-site devices, but the benzodiazepines and cannabinoids did not fulfil the needs of sensitivity.

Evaluation of an innovative sensor for measuring global and diffuse irradiance, and sunshine duration

NASA Astrophysics Data System (ADS)

Muneer, Tariq; Zhang, Xiaodong; Wood, John

2002-03-01

Delta-T Device Limited of Cambridge, UK have developed an integrated device which enables simultaneous measurement of horizontal global and diffuse irradiance as well as sunshine status at any given instance in time. To evaluate the performance of this new device, horizontal global and diffuse irradiance data were simultaneously collected from Delta-T device and Napier University's CIE First Class daylight monitoring station. To enable a cross check a Kipp & Zonen CM11 global irradiance sensor has also been installed in Currie, south-west Edinburgh. Sunshine duration data have been recorded at the Royal Botanical Garden, Edinburgh using their Campbell-Stokes recorder. Hourly data sets were analysed and plotted within the Microsoft Excel environment. Using the common statistical measures, Root Mean Square Difference (RMSD) and Mean Bias Difference (MBD) the accuracy of measurements of Delta-T sensor's horizontal global and diffuse irradiance, and sunshine duration were investigated. The results show a good performance on the part of Delta-T device for the measurement of global and diffuse irradiance. The sunshine measurements were found to have a lack of consistency and accuracy. It is argued herein that the distance between the respective sensors and the poor accuracy of Campbell-Stokes recorder may be contributing factors to this phenomenon.

Experimental and numeric investigation of Impella pumps as cavopulmonary assistance for a failing Fontan.

PubMed

Haggerty, Christopher M; Fynn-Thompson, Francis; McElhinney, Doff B; Valente, Anne Marie; Saikrishnan, Neelakantan; Del Nido, Pedro J; Yoganathan, Ajit P

2012-09-01

This study sought to evaluate the performance of microaxial ventricular assist devices for the purposes of supporting failing Fontan physiology by decreasing central venous pressure. Three Abiomed Impella pumps (Abiomed, Inc, Danvers, Mass) were evaluated in a mock circulatory system of the Fontan circuit. The local response of pressures and flows to pump function was assessed as a function of pump speed and pulmonary vascular resistance at a high baseline central venous pressure. For one device, subsequent modeling studies were conducted using a lumped parameter model of the single ventricle circuit. The left ventricular devices (Impella 2.5, 5.0) were shown to be suboptimal as single device solutions for cavopulmonary support. The small area of these devices relative to vessel diameter led to significant flow recirculation without an obstructive separator in place. Furthermore, downstream pressure augmentation adversely affected the pressure in the superior vena cava. The use of 2 devices would be mandatory for successful support. The right-sided device (Impella RP), whose outflow was positioned in the left pulmonary artery, demonstrated decreased flow recirculation and did not impede superior caval venous flow. Although static pressure is still required to drive flow through the opposite lung, numeric modeling demonstrated the potential for modest but significant improvements in lowering the central venous pressure (2-8 mm Hg). Left-sided microaxial pumps are not well suited for cavopulmonary support because of severe flow recirculation and the need for multiple devices. The right-ventricular Impella device provides improved performance by directing flow into the pulmonary artery, resulting in modest decreases in central venous pressure. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Experimental evaluations of wearable ECG monitor.

PubMed

Ha, Kiryong; Kim, Youngsung; Jung, Junyoung; Lee, Jeunwoo

2008-01-01

Healthcare industry is changing with ubiquitous computing environment and wearable ECG measurement is one of the most popular approaches in this healthcare industry. Reliability and performance of healthcare device is fundamental issue for widespread adoptions, and interdisciplinary perspectives of wearable ECG monitor make this more difficult. In this paper, we propose evaluation criteria considering characteristic of both ECG measurement and ubiquitous computing. With our wearable ECG monitors, various levels of experimental analysis are performed based on evaluation strategy.

Small Business Innovations

NASA Technical Reports Server (NTRS)

1992-01-01

The purpose of QASE RT is to enable system analysts and software engineers to evaluate performance and reliability implications of design alternatives. The program resulted from two Small Business Innovation Research (SBIR) projects. After receiving a description of the system architecture and workload from the user, QASE RT translates the system description into simulation models and executes them. Simulation provides detailed performance evaluation. The results of the evaluations are service and response times, offered load and device utilizations and functional availability.

Hand controllers for teleoperation. A state-of-the-art technology survey and evaluation

NASA Technical Reports Server (NTRS)

Brooks, T. L.; Bejczy, A. K.

1985-01-01

Hand controller technology for teleoperation is surveyed in three major catagories: (1) hand grip design, (2) control input devices, and (3) control strategies. In the first category, 14 hand grip designs are reviewed and evaluated in light of human factor considerations. In the second, 12 hand controller input devices are evaluated in terms of task performance, configuration and force feedback, controller/slave correspondence, operating volume, operator workload, human limitations, cross coupling, singularities, anthropomorphic characteristics, physical complexity, control/display interference, accuracy, technological base, cost, and reliability. In the third catagory, control strategies, commonly called control modes, are surveyed and evaluated. The report contains a bibliography with 189 select references on hand controller technology.

In vitro corrosion resistance of porous NiTi intervertebral fusion devices

NASA Astrophysics Data System (ADS)

Schrooten, Jan; Assad, Michel; Van Humbeeck, Jan; Leroux, Michel A.

2007-02-01

Porous titanium-nickel (PTN) intervertebral fusion devices, produced by self-propagating high-temperature synthesis, represent an alternative to traditional long-term implants in the orthopaedic field. PTN promotes tissue ingrowth and has succeeded short-term and long-term biocompatibility in vivo testing. In this in vitro study, the PTN morphology was characterized using microfocus computer tomography (μCT) in order to calculate the active PTN surface. Potentiodynamic polarization testing was then performed to evaluate the in vitro corrosion resistance of PTN devices in Hanks' based salt solution. Direct coupling experiments of PTN with Ti6Al4V were also performed in order to establish the galvanic corrosion resistance of PTN intervertebral implants in the presence of potential Ti6Al4V supplemental fixation devices. Compared to the behaviour of other orthopaedic biomaterials and solid NiTi devices, PTN devices showed a level of corrosion resistance that is comparable to other NiTi devices and acceptable for the intended orthopaedic application. Further improvement of the corrosion resistance is still possible by specific electrochemical surface treatments.

Performance analysis of GeSn-alloy-based multiple quantum well transistor laser

NASA Astrophysics Data System (ADS)

Ranjan, Ravi; Pareek, Prakash; Anwer Askari, Syed Sadique; Das, Mukul K.

2018-02-01

The Group IV Photonics (GFP) which include an alloy of Si, Ge & Sn that gives a direct bandgap material (GeSn, SiGeSn) in near and mid-IR region used as an active material in photonics devices. The multiple quantum well SiGeSn/GeSn transistor laser structure is considered in this paper and performance parameters are evaluated for the same. The result shows that the threshold base current density (2.6 kA/cm2) for the proposed device initially decreases with increasing number of quantum well (QW) and later on it saturates. The current gain and output photon density of the device decreases and increases respectively, with increasing number of QW.

Performance evaluation of integrating detectors for near-infrared fluorescence molecular imaging

NASA Astrophysics Data System (ADS)

Zhu, Banghe; Rasmussen, John C.; Sevick-Muraca, Eva M.

2014-05-01

Although there has been a plethora of devices advanced for clinical translation, there has been no standards to compare and determine the optical device for fluorescence molecular imaging. In this work, we compare different CCD configurations using a solid phantom developed to mimic pM - fM concentrations of near-infrared fluorescent dyes in tissues. Our results show that intensified CCD systems (ICCDs) offer greater contrast at larger signal-tonoise ratios (SNRs) in comparison to their un-intensified CCD systems operated at clinically reasonable, sub-second acquisition times. Furthermore, we compared our investigational ICCD device to the commercial NOVADAQ SPY system, demonstrating different performance in both SNR and contrast.

Relative risk analysis of the use of radiation-emitting medical devices: A preliminary application

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

Jones, E.D.

This report describes the development of a risk analysis approach for evaluating the use of radiation-emitting medial devices. This effort was performed by Lawrence Livermore National Laboratory for the US Nuclear Regulatory Commission (NRC). The assessment approach has bee applied to understand the risks in using the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step to evaluate the potential role of risk analysis for developing regulations and quality assurance requirements in the use of nuclear medical devices. The risk approach identifies and assesses the most likely risk contributors and their relative importance for the medicalmore » system. The approach uses expert screening techniques and relative risk profiling to incorporate the type, quality, and quantity of data available and to present results in an easily understood form.« less

Design and evaluation of excitation light source device for fluorescence endoscope

NASA Astrophysics Data System (ADS)

Lim, Hyun Soo

2009-06-01

This study aims at designing and evaluating light source devices that can stably generate light with various wavelengths in order to make possible PDD using a photosensitizer and diagnosis using auto-fluorescence. The light source was a Xenon lamp and filter wheel, composed of an optical output control through Iris and filters with several wavelength bands. It also makes the inducement of auto-fluorescence possible because it is designed to generate a wavelength band of 380-420nm, 430-480nm, and 480-560nm. The transmission part of the light source was developed to enhance the efficiency of light transmission. To evaluate this light source, the characteristics of light output and wavelength band were verified. To validate the capability of this device as PDD, the detection of auto-fluorescence using mouse models was performed.

Cerebral NIRS performance testing with molded and 3D-printed phantoms (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wang, Jianting; Huang, Stanley; Chen, Yu; Welle, Cristin G.; Pfefer, T. Joshua

2017-03-01

Near-infrared spectroscopy (NIRS) has emerged as a low-cost, portable approach for rapid, point-of-care detection of hematomas caused by traumatic brain injury. As a new technology, there is a need to develop standardized test methods for objective, quantitative performance evaluation of these devices. Towards this goal, we have developed and studied two types of phantom-based testing approaches. The first involves 3D-printed phantoms incorporating hemoglobin-filled inclusions. Phantom layers representing specific cerebral tissues were printed using photopolymers doped with varying levels of titanium oxide and black resin. The accuracy, precision and spectral dependence of printed phantom optical properties were validated using spectrophotometry. The phantom also includes a hematoma inclusion insert which was filled with a hemoglobin solution. Oxygen saturation levels were modified by adding sodium dithionite at calibrated concentrations. The second phantom approach involves molded silicone layers with a superficial region - simulating the scalp and skull - comprised of removable layers to vary hematoma size and depth, and a bottom layer representing brain matter. These phantoms were tested with both a commercial hematoma detector and a custom NIRS system to optimize their designs and validate their utility in performing inter-device comparisons. The effects of hematoma depth, diameter, and height, as well as tissue optical properties and biological variables including hemoglobin saturation level and scalp/skull thickness were studied. Results demonstrate the ability to quantitatively compare NIRS device performance and indicate the promise of using 3D printing to achieve phantoms with realistic variations in tissue optical properties for evaluating biophotonic device performance.

[Effects of breathing exercises on breathing pattern and thoracoabdominal motion after gastroplasty].

PubMed

Tomich, Georgia Miranda; França, Danielle Corrêa; Diniz, Marco Túlio Costa; Britto, Raquel Rodrigues; Sampaio, Rosana Ferreira; Parreira, Verônica Franco

2010-01-01

To evaluate breathing pattern and thoracoabdominal motion during breathing exercises. Twenty-four patients with class II or III obesity (18 women; 6 men) were studied on the second postoperative day after gastroplasty. The mean age was 37 +/- 11 years, and the mean BMI was 44 +/- 3 kg/m(2). Diaphragmatic breathing, incentive spirometry with a flow-oriented device and incentive spirometry with a volume-oriented device were performed in random order. Respiratory inductive plethysmography was used in order to measure respiratory variables and thoracoabdominal motion. Comparisons among the three exercises showed significant differences: tidal volume was higher during incentive spirometry (with the flow-oriented device or with the volume-oriented device) than during diaphragmatic breathing; the respiratory rate was lower during incentive spirometry with the volume-oriented device than during incentive spirometry with the flow-oriented device; and minute ventilation was higher during incentive spirometry (with the flow-oriented device or with the volume-oriented device) than during diaphragmatic breathing. Rib cage motion did not vary during breathing exercises, although there was an increase in thoracoabdominal asynchrony, especially during incentive spirometry with the flow-oriented device. Among the breathing exercises evaluated, incentive spirometry with the volume-oriented device provided the best results, because it allowed slower, deeper inhalation.

In vivo evaluation of glucose permeability of an immunoisolation device intended for islet transplantation: a novel application of the microdialysis technique.

PubMed

Rafael, E; Wernerson, A; Arner, P; Wu, G S; Tibell, A

1999-01-01

Immunoisolation devices consist of semipermeable membranes chosen to protect the islets from the immune system but still allow sufficient passage of nutrients, oxygen, and the therapeutic products, insulin. The exchange between the device and the microcirculation will influence the survival of the graft as well as the metabolic efficacy of the islet implant. Glucose is the important trigger factor for insulin secretion. In this study, we evaluate the in vivo glucose permeability of the Theracyte immunoisolation device at various times after implantation. Empty devices were implanted s.c. in rats. The glucose kinetics in the device was compared to that in the SC tissue during i.v. glucose tolerance tests (IVGTTs), using the microdialysis technique. In rats studied on day 1, or 1, 2, and 4 weeks after implantation, the peak glucose levels (Cmax) were significantly lower, the times-to-peak (TTP) were significantly longer, and the areas under the curve during the first 40 min (AUC(0-40)) were significantly smaller in the device than in the SC fat. However, at 3 months all parameters improved and Cmax, TTP, and AUC(0-40) in the device did not differ significantly from those measured in the SC fat. Thus, during the first 4 weeks the device constitutes a significant diffusion barrier, but at 3 months the exchange between the lumen of devices and the blood stream improves. Our data indicate that implantation of the device several months before transplantation of the cellular graft would improve the exchange across the membrane during the early posttransplant period. This should have positive effects on graft survival and function. We also suggest that microdialysis is a useful tool for evaluating the in vivo performance of macroencapsulation devices.

Clinical Evaluation of a Novel Intrarectal Device for Management of Fecal Incontinence in Bedridden Patients.

PubMed

Singh, Sandeep; Bhargava, Balram; Vasantha, Padma; Bhatia, Rohit; Sharma, Hanish; Pal, Sujoy; Sahni, Peush; Makharia, Govind K

The primary objective of the study was to evaluate the safety and efficacy of a stool management kit (SMK) for containment of fecal incontinence in hospitalized bedridden patients. A single-group quasi-experimental study. Twenty bedridden adults who had at least 1 episode of fecal incontinence in the prior 24 hours participated in the study. The study setting was the neurological unit of the All India Institute of Medical Sciences in New Delhi, India. The study was carried out in 2 phases. The device was placed in situ for up to 24 hours in 10 patients during phase I of the study and up to 120 hours in an additional 10 patients during phase II. Participants were assessed for anorectal injury and peripheral device leakage on a 4- to 6-hourly basis. Sigmoidoscopy was performed to evaluate for any mucosal trauma or alteration of anorectal pathology after retrieval of the device. The device was successfully placed in all patients following the first attempt to place the device; 80% of patients retained the device until planned removal. The SMK diverted fecal matter without anal leakage in 174 (93.5%) out of 186 assessment points in a group of 20 patients. The devices remained in situ for 21 ± 0.2 and 84.5 ± 38.9 hours during phase I and phase II, respectively. None experienced anorectal bleeding, sphincter injury, or mucosal ulceration with device usage. Post-device sigmoidoscopy revealed erythema at the site of diverter placement in 2 participants. Study findings suggest that the SMK successfully diverted liquid to semiformed fecal exudate without peripheral device leakage in 93.5% of bedridden patients. No serious adverse events occurred. Additional research is needed to compare its effectiveness with that of currently available intrarectal balloon devices.

Re-centering variable friction device for vibration control of structures subjected to near-field earthquakes

NASA Astrophysics Data System (ADS)

Ozbulut, Osman E.; Hurlebaus, Stefan

2011-11-01

This paper proposes a re-centering variable friction device (RVFD) for control of civil structures subjected to near-field earthquakes. The proposed hybrid device has two sub-components. The first sub-component of this hybrid device consists of shape memory alloy (SMA) wires that exhibit a unique hysteretic behavior and full recovery following post-transformation deformations. The second sub-component of the hybrid device consists of variable friction damper (VFD) that can be intelligently controlled for adaptive semi-active behavior via modulation of its voltage level. In general, installed SMA devices have the ability to re-center structures at the end of the motion and VFDs can increase the energy dissipation capacity of structures. The full realization of these devices into a singular, hybrid form which complements the performance of each device is investigated in this study. A neuro-fuzzy model is used to capture rate- and temperature-dependent nonlinear behavior of the SMA components of the hybrid device. An optimal fuzzy logic controller (FLC) is developed to modulate voltage level of VFDs for favorable performance in a RVFD hybrid application. To obtain optimal controllers for concurrent mitigation of displacement and acceleration responses, tuning of governing fuzzy rules is conducted by a multi-objective heuristic optimization. Then, numerical simulation of a multi-story building is conducted to evaluate the performance of the hybrid device. Results show that a re-centering variable friction device modulated with a fuzzy logic control strategy can effectively reduce structural deformations without increasing acceleration response during near-field earthquakes.

Field Performance versus Standard Test Condition Efficiency of Tandem Solar Cells and the Singular Case of Perovskites/Silicon Devices.

PubMed

Dupré, Olivier; Niesen, Bjoern; De Wolf, Stefaan; Ballif, Christophe

2018-01-18

Multijunction cells may offer a cost-effective route to boost the efficiency of industrial photovoltaics. For any technology to be deployed in the field, its performance under actual operating conditions is extremely important. In this perspective, we evaluate the impact of spectrum, light intensity, and module temperature variations on the efficiency of tandem devices with crystalline silicon bottom cells with a particular focus on perovskite top cells. We consider devices with different efficiencies and calculate their energy yields using field data from Denver. We find that annual losses due to differences between operating conditions and standard test conditions are similar for single-junction and four-terminal tandem devices. The additional loss for the two-terminal tandem configuration caused by current mismatch reduces its performance ratio by only 1.7% when an optimal top cell bandgap is used. Additionally, the unusual bandgap temperature dependence of perovskites is shown to have a positive, compensating effect on current mismatch.

Implementing bright light treatment for MSFC payload operations shiftworkers

NASA Technical Reports Server (NTRS)

Hayes, Benita C.; Stewart, Karen T.; Eastman, Charmane I.

1994-01-01

Intense light can phase-shift circadian rhythms and improve performance, sleep, and wellbeing during shiftwork simulations, but to date there have been very few attempts to administer light treatment to real shiftworkers. We have developed procedures for implementing light treatment and have conducted controlled trials of light treatment for MSFC Payload Operations staff during the USML-1 mission. We found that treatment had beneficial effects on fatigue, alertness, self-rated job performance, sleep, mood, and work attendance. Although there are portable bright light boxes commercially available, there is no testing protocol and little performance information available. We measure the illuminance of two candidate boxes for use in this study and found that levels were consistently lower than those advertised by manufacturers. A device was developed to enhance the illuminance output of such units. This device increased the illuminance by at least 60 % and provided additional improvements in visual comfort and overall exposure. Both the design of this device and some suggested procedures for evaluating light devices are presented.

Note: Motor-piezoelectricity coupling driven high temperature fatigue device

NASA Astrophysics Data System (ADS)

Ma, Z. C.; Du, X. J.; Zhao, H. W.; Ma, X. X.; Jiang, D. Y.; Liu, Y.; Ren, L. Q.

2018-01-01

The design and performance evaluation of a novel high temperature fatigue device simultaneously driven by servo motor and piezoelectric actuator is our focus. The device integrates monotonic and cyclic loading functions with a maximum tensile load of 1800 N, driving frequency of 50 Hz, alternating load of 95 N, and maximum service temperature of 1200 °C. Multimodal fatigue tests with arbitrary combinations of static and dynamic loads are achieved. At temperatures that range from RT to 1100 °C, the tensile and tensile-fatigue coupling mechanical behaviors of UM Co50 alloys are investigated to verify the feasibility of the device.

Characteristics of enhanced-mode AlGaN/GaN MIS HEMTs for millimeter wave applications

NASA Astrophysics Data System (ADS)

Lee, Jong-Min; Ahn, Ho-Kyun; Jung, Hyun-Wook; Shin, Min Jeong; Lim, Jong-Won

2017-09-01

In this paper, an enhanced-mode (E-mode) AlGaN/GaN high electron mobility transistor (HEMT) was developed by using 4-inch GaN HEMT process. We designed and fabricated Emode HEMTs and characterized device performance. To estimate the possibility of application for millimeter wave applications, we focused on the high frequency performance and power characteristics. To shift the threshold voltage of HEMTs we applied the Al2O3 insulator to the gate structure and adopted the gate recess technique. To increase the frequency performance the e-beam lithography technique was used to define the 0.15 um gate length. To evaluate the dc and high frequency performance, electrical characterization was performed. The threshold voltage was measured to be positive value by linear extrapolation from the transfer curve. The device leakage current is comparable to that of the depletion mode device. The current gain cut-off frequency and the maximum oscillation frequency of the E-mode device with a total gate width of 150 um were 55 GHz and 168 GHz, respectively. To confirm the power performance for mm-wave applications the load-pull test was performed. The measured power density of 2.32 W/mm was achieved at frequencies of 28 and 30 GHz.

Bringing the skills laboratory home: an affordable webcam-based personal trainer for developing laparoscopic skills.

PubMed

Kobayashi, Sow Alfred; Jamshidi, Ramin; O'Sullivan, Patricia; Palmer, Barnard; Hirose, Shinjiro; Stewart, Lygia; Kim, Edward Hyung

2011-01-01

The purpose of this work was to develop a more flexible system of laparoscopic surgery training with demonstrated effectiveness and construct validity. A personal, portable, durable laparoscopic trainer can be designed at low cost. The evaluation of expert surgeons on this device will reveal technical superiority over novices. With practice, novice surgeons can improve their performance significantly as measured by scores derived from performing skills with this training device. Prospective trial with observation and intervention components. The first aspect was observational comparison of novice and expert performance. The second was a prospective static-group comparison with pretest/posttest single-sample design. Tertiary-care academic medical center with affiliated general surgery residency. A total of 21 junior surgical residents and 5 experienced operators. Performance was assessed by the 5 tasks in the McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS): pegboard transfer, pattern cutting, placement of ligating loop, extracorporeal knotting, and intracorporeal knotting. Each task was assessed for accuracy and speed. Expert surgeons scored significantly higher than novices on total score and 4 of the 5 MISTELS tasks (peg transfer, pattern cut, extracorporeal knot, and intracorporeal knot). After 4 months of home-based training, the novices improved in total score and 3 of the 5 tasks (peg transfer, pattern cut, and extracorporeal knot). A low-cost personal laparoscopic training device can be built by individual residents. With their use, residents can significantly improve performance in important surgical skills. Evaluation of the system supports its validity. Copyright © 2011 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Ureteroscopic biopsy of upper tract urothelial carcinoma: comparison of basket and forceps.

PubMed

Kleinmann, Nir; Healy, Kelly A; Hubosky, Scott G; Margel, David; Bibbo, Marluce; Bagley, Demetrius H

2013-12-01

To compare two different biopsy devices for upper tract urothelial carcinoma (UTUC) and evaluate the pathologic result obtained by these devices. From January 2008 to December 2010, 414 ureteroscopies were performed and 504 biopsies were taken for evaluation of UTUC. Two biopsy devices were compared: 2.4F stainless steel flat wire basket and 3F cup biopsy forceps. The effect of the biopsy device on obtaining an adequate pathologic specimen was evaluated using univariate and multivariate binary logistic regression analysis. We also investigated whether tumor grade determination was affected by the biopsy device among patients with a diagnostic biopsy. Diagnosis was successful in 63% and 94% in the forceps and basket groups, respectively (P < 0.0001). Among biopsies with a definite diagnosis of UTUC, specific grade was determined in 80% and 93% in the forceps and basket groups, respectively (P = 0.033). In subgroup analysis of tumors larger than 10 mm in diameter, diagnosis was obtained in 80% and 94% in the forceps and basket groups, respectively (P = 0.037). Cytologic evaluation was found to increase diagnostic rates. The stainless steel flat wire basket was shown to be superior to the 3F cup biopsy forceps in terms of obtaining tissue diagnosis and providing specific grade.

Development of UItra-Low Temperature Motor Controllers: Ultra Low Temperatures Evaluation and Characterization of Semiconductor Technologies For The Next Generation Space Telescope

NASA Technical Reports Server (NTRS)

Elbuluk, Malik E.

2003-01-01

Electronics designed for low temperature operation will result in more efficient systems than room temperature. This improvement is a result of better electronic, electrical, and thermal properties of materials at low temperatures. In particular, the performance of certain semiconductor devices improves with decreasing temperature down to ultra-low temperature (-273 'C). The Low Temperature Electronics Program at the NASA Glenn Research Center focuses on research and development of electrical components and systems suitable for applications in deep space missions. Research is being conducted on devices and systems for use down to liquid helium temperatures (-273 'C). Some of the components that are being characterized include semiconductor switching devices, resistors, magnetics, and capacitors. The work performed this summer has focused on the evaluation of silicon-, silicon-germanium- and gallium-Arsenide-based (GaAs) bipolar, MOS and CMOS discrete components and integrated circuits (ICs), from room temperature (23 'C) down to ultra low temperatures (-263 'C).

125Mbps ultra-wideband system evaluation for cortical implant devices.

PubMed

Luo, Yi; Winstead, Chris; Chiang, Patrick

2012-01-01

This paper evaluates the performance of a 125Mbps Impulse Ratio Ultra-Wideband (IR-UWB) system for cortical implant devices by using low-Q inductive coil link operating in the near-field domain. We examine design tradeoffs between transmitted signal amplitude, reliability, noise and clock jitter. The IR-UWB system is modeled using measured parameters from a reported UWB transceiver implemented in 90nm-CMOS technology. Non-optimized inductive coupling coils with low-Q value for near-field data transmission are modeled in order to build a full channel from the transmitter (Tx) to the receiver (Rx). On-off keying (OOK) modulation is used together with a low-complexity convolutional error correcting code. The simulation results show that even though the low-Q coils decrease the amplitude of the received pulses, the UWB system can still achieve acceptable performance when error correction is used. These results predict that UWB is a good candidate for delivering high data rates in cortical implant devices.

Thermic sealing in femoral catheterisation: First experience with the Secure Device.

PubMed

Sacherer, Michael; Kolesnik, Ewald; von Lewinski, Friederike; Verheyen, Nicolas; Brandner, Karin; Wallner, Markus; Eaton, Deborah M; Luha, Olev; Zweiker, Robert; von Lewinski, Dirk

2018-04-03

Devices currently used to achieve hemostasis of the femoral artery following percutaneous cardiac catheterization are associated with vascular complications and remnants of artificial materials are retained at the puncture site. The SECURE arterial closure device induces hemostasis by utilizing thermal energy, which causes collagen shrinking and swelling. In comparison to established devices, it has the advantage of leaving no foreign material in the body following closing. This study was designed to evaluate the efficacy and safety of the SECURE device to close the puncture site following percutaneous cardiac catheterization. The SECURE device was evaluated in a prospective non-randomized single-centre trial with patients undergoing 6 F invasive cardiac procedures. A total of 67 patients were enrolled and the device was utilized in 63 patients. 50 diagnostic and 13 interventional cases were evaluated. Femoral artery puncture closure was performed immediately after completion of the procedure. Time to hemostasis (TTH), time to ambulation (TTA) and data regarding short-term and 30-day clinical follow-up were recorded. Mean TTH was 4:30 ± 2:15 min in the overall observational group. A subpopulation of patients receiving anticoagulants had a TTH of 4:53 ± 1:43 min. There were two access site complications (hematoma > 5 cm). No major adverse events were identified during hospitalization or at the 30 day follow-up. The new SECURE device demonstrates that it is feasible in diagnostic and interventional cardiac catheterization. With respect to safety, the SECURE device was non-inferior to other closure devices as tested in the ISAR closure trial.

Testing of state roadside safety systems. Volume I, Technical report

DOT National Transportation Integrated Search

1999-04-01

The purpose of this study is to crash test and evaluate new or modified roadside safety hardware and, where necessary, redesign the devices to improve their impact performance. The three major areas addressed in this study are the impact performance ...

40 CFR 610.35 - Driveability and performance tests.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Driveability and performance tests. 610.35 Section 610.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria...

40 CFR 610.35 - Driveability and performance tests.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Driveability and performance tests. 610.35 Section 610.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria...

40 CFR 610.35 - Driveability and performance tests.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Driveability and performance tests. 610.35 Section 610.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria...

40 CFR 610.35 - Driveability and performance tests.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Driveability and performance tests. 610.35 Section 610.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria...

40 CFR 610.35 - Driveability and performance tests.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Driveability and performance tests. 610.35 Section 610.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria...

Potential of connected devices to optimize cattle reproduction.

PubMed

Saint-Dizier, Marie; Chastant-Maillard, Sylvie

2018-05-01

Estrus and calving are two major events of reproduction that benefit from connected devices because of their crucial importance in herd economics and the amount of time required for their detection. The objectives of this review are to: 1) provide an update on performances reached by sensor systems to detect estrus and calving time; 2) discuss current economic issues related to connected devices for the management of cattle reproduction; 3) propose perspectives for these devices. The main physiological parameters monitored separately or in combination by connected devices are the cow activity, body temperature and rumination or eating behavior. The combination of several indicators in one sensor may maximize the performances of estrus and calving detection. An effort remains to be made for the prediction of calvings that will require human assistance (dystocia). The main reasons to invest in connected devices are to optimize herd reproductive performances and reduce labor on farm. The economic benefit was evaluated for estrus detection and depends on the initial herd performances, herd size, labor cost and price of the equipment. Major issues associated with the use of automated sensor systems are the weight of financial investment, the lack of economic analysis and limited skills of the users to manage associated technologies. In the near future, connected devices may allow a precise phenotyping of reproductive and health traits on animals and could help to improve animal welfare and public perception of animal production. Copyright © 2017 Elsevier Inc. All rights reserved.

An evaluation of radiation damage to solid state components flown in low earth orbit satellites.

PubMed

Shin, Myung-Won; Kim, Myung-Hyun

2004-01-01

The effects of total ionising radiation dose upon commercial off-the-shelf semiconductors fitted to satellites operating in low Earth orbit (LEO) conditions was evaluated. The evaluation was performed for the Korea Institute of Technology SATellite-1, (KITSAT-1) which was equipped with commercial solid state components. Two approximate calculation models for space radiation shielding were developed. Verification was performed by comparing the results with detailed three-dimensional calculations using the Monte-Carlo method and measured data from KITSAT-1. It was confirmed that the developed approximate models were reliable for satellite shielding calculations. It was also found that commercial semiconductor devices, which were not radiation hardened, could be damaged within their lifetime due to the total ionising dose they are subject to in the LEO environment. To conclude, an intensive shielding analysis should be considered when commercial devices are used.

Lustre Distributed Name Space (DNE) Evaluation at the Oak Ridge Leadership Computing Facility (OLCF)

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

Simmons, James S.; Leverman, Dustin B.; Hanley, Jesse A.

This document describes the Lustre Distributed Name Space (DNE) evaluation carried at the Oak Ridge Leadership Computing Facility (OLCF) between 2014 and 2015. DNE is a development project funded by the OpenSFS, to improve Lustre metadata performance and scalability. The development effort has been split into two parts, the first part (DNE P1) providing support for remote directories over remote Lustre Metadata Server (MDS) nodes and Metadata Target (MDT) devices, while the second phase (DNE P2) addressed split directories over multiple remote MDS nodes and MDT devices. The OLCF have been actively evaluating the performance, reliability, and the functionality ofmore » both DNE phases. For these tests, internal OLCF testbed were used. Results are promising and OLCF is planning on a full DNE deployment by mid-2016 timeframe on production systems.« less

Comparative Study of Assisted Ambulation and Perceived Exertion With the Wheeled Knee Walker and Axillary Crutches in Healthy Subjects.

PubMed

Kocher, Benjamin K; Chalupa, Robyn L; Lopez, Donna M; Kirk, Kevin L

2016-11-01

Functional limitations after lower extremity surgery often require the use of an assistive device for ambulation during rehabilitation and recovery. There are no known objective data evaluating the wheeled knee walker as an assistive device for protected ambulation. The purpose of this study was to compare assisted ambulation and perceived exertion with the wheeled knee walker and the axillary crutches in healthy participants. A prospective, randomized crossover study was performed using 24 healthy volunteers. Each participant performed a 6-minute walk test (6MWT) using each assistive device in a crossover manner. Preactivity and postactivity heart rates were recorded. The self-selected walking velocity (SSWV) was calculated and the participant's rating of perceived exertion was recorded using the OMNI Rating of Perceived Exertion (OMNI-RPE). Participant's preference for assistive device was identified. The 6MWT, SSWV, and the Omni-RPE were evaluated using paired t tests and determined to be statistically significant for the wheeled knee walker compared with axillary crutches. Evaluation of the preactivity and postactivity heart rates demonstrated a statistically significant difference for the wheeled knee walker compared with axillary crutches. The wheeled knee walker was preferred by 88% of participants. The wheeled knee walker provided increased assisted ambulation and had a lower rating of perceived exertion than axillary crutches on level surfaces in healthy participants. Level III, comparative study. © The Author(s) 2016.

Noise tolerance in wavelength-selective switching of optical differential quadrature-phase-shift-keying pulse train by collinear acousto-optic devices.

PubMed

Goto, Nobuo; Miyazaki, Yasumitsu

2014-06-01

Optical switching of high-bit-rate quadrature-phase-shift-keying (QPSK) pulse trains using collinear acousto-optic (AO) devices is theoretically discussed. Since the collinear AO devices have wavelength selectivity, the switched optical pulse trains suffer from distortion when the bandwidth of the pulse train is comparable to the pass bandwidth of the AO device. As the AO device, a sidelobe-suppressed device with a tapered surface-acoustic-wave (SAW) waveguide and a Butterworth-type filter device with a lossy SAW directional coupler are considered. Phase distortion of optical pulse trains at 40 to 100  Gsymbols/s in QPSK format is numerically analyzed. Bit-error-rate performance with additive Gaussian noise is also evaluated by the Monte Carlo method.

Evidence of Filamentary Switching in Oxide-based Memory Devices via Weak Programming and Retention Failure Analysis

NASA Astrophysics Data System (ADS)

Younis, Adnan; Chu, Dewei; Li, Sean

2015-09-01

Further progress in high-performance microelectronic devices relies on the development of novel materials and device architectures. However, the components and designs that are currently in use have reached their physical limits. Intensive research efforts, ranging from device fabrication to performance evaluation, are required to surmount these limitations. In this paper, we demonstrate that the superior bipolar resistive switching characteristics of a CeO2:Gd-based memory device can be manipulated by means of UV radiation, serving as a new degree of freedom. Furthermore, the metal oxide-based (CeO2:Gd) memory device was found to possess electrical and neuromorphic multifunctionalities. To investigate the underlying switching mechanism of the device, its plasticity behaviour was studied by imposing weak programming conditions. In addition, a short-term to long-term memory transition analogous to the forgetting process in the human brain, which is regarded as a key biological synaptic function for information processing and data storage, was realized. Based on a careful examination of the device’s retention behaviour at elevated temperatures, the filamentary nature of switching in such devices can be understood from a new perspective.

Evidence of Filamentary Switching in Oxide-based Memory Devices via Weak Programming and Retention Failure Analysis

PubMed Central

Younis, Adnan; Chu, Dewei; Li, Sean

2015-01-01

Further progress in high-performance microelectronic devices relies on the development of novel materials and device architectures. However, the components and designs that are currently in use have reached their physical limits. Intensive research efforts, ranging from device fabrication to performance evaluation, are required to surmount these limitations. In this paper, we demonstrate that the superior bipolar resistive switching characteristics of a CeO2:Gd-based memory device can be manipulated by means of UV radiation, serving as a new degree of freedom. Furthermore, the metal oxide-based (CeO2:Gd) memory device was found to possess electrical and neuromorphic multifunctionalities. To investigate the underlying switching mechanism of the device, its plasticity behaviour was studied by imposing weak programming conditions. In addition, a short-term to long-term memory transition analogous to the forgetting process in the human brain, which is regarded as a key biological synaptic function for information processing and data storage, was realized. Based on a careful examination of the device’s retention behaviour at elevated temperatures, the filamentary nature of switching in such devices can be understood from a new perspective. PMID:26324073

Handheld ultrasound array imaging device

NASA Astrophysics Data System (ADS)

Hwang, Juin-Jet; Quistgaard, Jens

1999-06-01

A handheld ultrasound imaging device, one that weighs less than five pounds, has been developed for diagnosing trauma in the combat battlefield as well as a variety of commercial mobile diagnostic applications. This handheld device consists of four component ASICs, each is designed using the state of the art microelectronics technologies. These ASICs are integrated with a convex array transducer to allow high quality imaging of soft tissues and blood flow in real time. The device is designed to be battery driven or ac powered with built-in image storage and cineloop playback capability. Design methodologies of a handheld device are fundamentally different to those of a cart-based system. As system architecture, signal and image processing algorithm as well as image control circuit and software in this device is deigned suitably for large-scale integration, the image performance of this device is designed to be adequate to the intent applications. To elongate the battery life, low power design rules and power management circuits are incorporated in the design of each component ASIC. The performance of the prototype device is currently being evaluated for various applications such as a primary image screening tool, fetal imaging in Obstetrics, foreign object detection and wound assessment for emergency care, etc.

Modeling synchronous voltage source converters in transmission system planning studies

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

Kosterev, D.N.

1997-04-01

A Voltage Source Converter (VSC) can be beneficial to power utilities in many ways. To evaluate the VSC performance in potential applications, the device has to be represented appropriately in planning studies. This paper addresses VSC modeling for EMTP, powerflow, and transient stability studies. First, the VSC operating principles are overviewed, and the device model for EMTP studies is presented. The ratings of VSC components are discussed, and the device operating characteristics are derived based on these ratings. A powerflow model is presented and various control modes are proposed. A detailed stability model is developed, and its step-by-step initialization proceduremore » is described. A simplified stability model is also derived under stated assumptions. Finally, validation studies are performed to demonstrate performance of developed stability models and to compare it with EMTP simulations.« less

Structural design of high-performance capacitive accelerometers using parametric optimization with uncertainties

NASA Astrophysics Data System (ADS)

Teves, André da Costa; Lima, Cícero Ribeiro de; Passaro, Angelo; Silva, Emílio Carlos Nelli

2017-03-01

Electrostatic or capacitive accelerometers are among the highest volume microelectromechanical systems (MEMS) products nowadays. The design of such devices is a complex task, since they depend on many performance requirements, which are often conflicting. Therefore, optimization techniques are often used in the design stage of these MEMS devices. Because of problems with reliability, the technology of MEMS is not yet well established. Thus, in this work, size optimization is combined with the reliability-based design optimization (RBDO) method to improve the performance of accelerometers. To account for uncertainties in the dimensions and material properties of these devices, the first order reliability method is applied to calculate the probabilities involved in the RBDO formulation. Practical examples of bulk-type capacitive accelerometer designs are presented and discussed to evaluate the potential of the implemented RBDO solver.

Feasibility and Limitations of Vaccine Two-Dimensional Barcoding Using Mobile Devices.

PubMed

Bell, Cameron; Guerinet, Julien; Atkinson, Katherine M; Wilson, Kumanan

2016-06-23

Two-dimensional (2D) barcoding has the potential to enhance documentation of vaccine encounters at the point of care. However, this is currently limited to environments equipped with dedicated barcode scanners and compatible record systems. Mobile devices may present a cost-effective alternative to leverage 2D vaccine vial barcodes and improve vaccine product-specific information residing in digital health records. Mobile devices have the potential to capture product-specific information from 2D vaccine vial barcodes. We sought to examine the feasibility, performance, and potential limitations of scanning 2D barcodes on vaccine vials using 4 different mobile phones. A unique barcode scanning app was developed for Android and iOS operating systems. The impact of 4 variables on the scan success rate, data accuracy, and time to scan were examined: barcode size, curvature, fading, and ambient lighting conditions. Two experimenters performed 4 trials 10 times each, amounting to a total of 2160 barcode scan attempts. Of the 1832 successful scans performed in this evaluation, zero produced incorrect data. Five-millimeter barcodes were the slowest to scan, although only by 0.5 seconds on average. Barcodes with up to 50% fading had a 100% success rate, but success rate deteriorated beyond 60% fading. Curved barcodes took longer to scan compared with flat, but success rate deterioration was only observed at a vial diameter of 10 mm. Light conditions did not affect success rate or scan time between 500 lux and 20 lux. Conditions below 20 lux impeded the device's ability to scan successfully. Variability in scan time was observed across devices in all trials performed. 2D vaccine barcoding is possible using mobile devices and is successful under the majority of conditions examined. Manufacturers utilizing 2D barcodes should take into consideration the impact of factors that limit scan success rates. Future studies should evaluate the effect of mobile barcoding on workflow and vaccine administrator acceptance.

Two Different Maintenance Strategies in the Hospital Environment: Preventive Maintenance for Older Technology Devices and Predictive Maintenance for Newer High-Tech Devices.

PubMed

Sezdi, Mana

2016-01-01

A maintenance program generated through the consideration of characteristics and failures of medical equipment is an important component of technology management. However, older technology devices and newer high-tech devices cannot be efficiently managed using the same strategies because of their different characteristics. This study aimed to generate a maintenance program comprising two different strategies to increase the efficiency of device management: preventive maintenance for older technology devices and predictive maintenance for newer high-tech devices. For preventive maintenance development, 589 older technology devices were subjected to performance verification and safety testing (PVST). For predictive maintenance development, the manufacturers' recommendations were used for 134 high-tech devices. These strategies were evaluated in terms of device reliability. This study recommends the use of two different maintenance strategies for old and new devices at hospitals in developing countries. Thus, older technology devices that applied only corrective maintenance will be included in maintenance like high-tech devices.

Two Different Maintenance Strategies in the Hospital Environment: Preventive Maintenance for Older Technology Devices and Predictive Maintenance for Newer High-Tech Devices

PubMed Central

Sezdi, Mana

2016-01-01

A maintenance program generated through the consideration of characteristics and failures of medical equipment is an important component of technology management. However, older technology devices and newer high-tech devices cannot be efficiently managed using the same strategies because of their different characteristics. This study aimed to generate a maintenance program comprising two different strategies to increase the efficiency of device management: preventive maintenance for older technology devices and predictive maintenance for newer high-tech devices. For preventive maintenance development, 589 older technology devices were subjected to performance verification and safety testing (PVST). For predictive maintenance development, the manufacturers' recommendations were used for 134 high-tech devices. These strategies were evaluated in terms of device reliability. This study recommends the use of two different maintenance strategies for old and new devices at hospitals in developing countries. Thus, older technology devices that applied only corrective maintenance will be included in maintenance like high-tech devices. PMID:27195666

Evaluation Of The Vehicle Radar Safety Systems Rashid Radar Safety Brake Collision Warning System, Final Report

DOT National Transportation Integrated Search

1988-02-01

THIS EVALUATION OF THE VEHICLE RADAR SAFETY SYSTEMS? ANTI-COLLISION DEVICE (HEREAFTER VRSS) WAS UNDERTAKEN BY THE OPERATOR PERFORMANCE AND SAFETY ANALYSIS DIVISION OF THE TRANSPORTATION SYSTEMS CENTER AT THE REQUEST OF THE NATIONAL HIGHWAY TRAFFIC SA...

PLANNING, CONSTRUCTION, AND EVALUATION OF MEDIA FOR TEACHING HIGH SCHOOL AND JUNIOR COLLEGE SCIENCE VIA TELEVISION FOR USE IN SELF INSTRUCTION. FINAL REPORT.

ERIC Educational Resources Information Center

WHITE, HARVEY E.

THIS IS AN OUTLINE OF PROCEDURES FOLLOWED IN DEVELOPING EXHIBITS SUITABLE AS AUTOINSTRUCTIONAL DEVICES AND AS DEMONSTRATION DEVICES FOR EDUCATIONAL TELEVISION PROGRAMS. THE 27 TEACHING EXHIBITS WERE DESIGNED TO HELP STUDENTS UNDERSTAND CONCEPTS AND PERFORM EXPERIMENTS IN PHYSICS, MATHEMATICS, CHEMISTRY, AND BIOLOGY. SOME OF THE EXHIBITS EMPLOYED…

Design, processing, and testing of lsi arrays for space station

NASA Technical Reports Server (NTRS)

Lile, W. R.; Hollingsworth, R. J.

1972-01-01

The design of a MOS 256-bit Random Access Memory (RAM) is discussed. Technological achievements comprise computer simulations that accurately predict performance; aluminum-gate COS/MOS devices including a 256-bit RAM with current sensing; and a silicon-gate process that is being used in the construction of a 256-bit RAM with voltage sensing. The Si-gate process increases speed by reducing the overlap capacitance between gate and source-drain, thus reducing the crossover capacitance and allowing shorter interconnections. The design of a Si-gate RAM, which is pin-for-pin compatible with an RCA bulk silicon COS/MOS memory (type TA 5974), is discussed in full. The Integrated Circuit Tester (ICT) is limited to dc evaluation, but the diagnostics and data collecting are under computer control. The Silicon-on-Sapphire Memory Evaluator (SOS-ME, previously called SOS Memory Exerciser) measures power supply drain and performs a minimum number of tests to establish operation of the memory devices. The Macrodata MD-100 is a microprogrammable tester which has capabilities of extensive testing at speeds up to 5 MHz. Beam-lead technology was successfully integrated with SOS technology to make a simple device with beam leads. This device and the scribing are discussed.

Bodily Expression Support for Creative Dance Education by Grasping-Type Musical Interface with Embedded Motion and Grasp Sensors †

PubMed Central

Yamaguchi, Tomoyuki; Kadone, Hideki

2017-01-01

Dance has been made mandatory as one of the physical education courses in Japan because it can cultivate capacities for expression and communication. Among several types of dance education, creative dance especially contributes to the cultivation of these capacities. However, creative dance requires some level of particular skills, as well as creativity, and it is difficult to presuppose these pre-requisites in beginner-level dancers without experience. We propose a novel supporting device for dance beginners to encourage creative dance performance by continuously generating musical sounds in real-time in accordance with their bodily movements. It has embedded sensors developed for this purpose. Experiments to evaluate the effectiveness of the device were conducted with ten beginner-level dancers. Using the proposed device, the subjects demonstrated enhanced creative dance movements with greater variety, evaluated in terms of Laban dance movement description. Also, using the device, they performed with better accuracy and repeatability in a task where they produced an imagined circular trajectory by hand. The proposed interface is effective in terms of creative dance activity and accuracy of motion generation for beginner-level dancers. PMID:28531114

Histological evaluation and optimization of surgical vessel sealing systems

NASA Astrophysics Data System (ADS)

Lathrop, Robert; Ryan, Thomas; Gaspredes, Jonathan; Woloszko, Jean; Coad, James E.

2017-02-01

Surgical vessel sealing systems are widely used to achieve hemostasis and dissection in open surgery and minimally invasive, laparoscopic surgery. This enabling technology was developed about 17 years ago and continues to evolve with new devices and systems achieving improved outcomes. Histopathological assessment of thermally sealed tissues is a valuable tool for refining and comparing performance among surgical vessel sealing systems. Early work in this field typically assessed seal time, burst rate, and failure rate (in-situ). Later work compared histological staining methods with birefringence to assess the extent of thermal damage to tissues adjacent to the device. Understanding the microscopic architecture of a sealed vessel is crucial to optimizing the performance of power delivery algorithms and device design parameters. Manufacturers rely on these techniques to develop new products. A system for histopathological evaluation of vessels and sealing performance was established, to enable the direct assessment of a treatment's tissue effects. The parameters included the commonly used seal time, pressure burst rate and failure rate, as well as extensions of the assessment to include its likelihood to form steam vacuoles, adjacent thermal effect near the device, and extent of thermally affected tissue extruded back into the vessel lumen. This comprehensive assessment method provides an improved means of assessing the quality of a sealed vessel and understanding the exact mechanisms which create an optimally sealed vessel.

Computational design and in vitro characterization of an integrated maglev pump-oxygenator.

PubMed

Zhang, Juntao; Taskin, M Ertan; Koert, Andrew; Zhang, Tao; Gellman, Barry; Dasse, Kurt A; Gilbert, Richard J; Griffith, Bartley P; Wu, Zhongjun J

2009-10-01

For the need for respiratory support for patients with acute or chronic lung diseases to be addressed, a novel integrated maglev pump-oxygenator (IMPO) is being developed as a respiratory assist device. IMPO was conceptualized to combine a magnetically levitated pump/rotor with uniquely configured hollow fiber membranes to create an assembly-free, ultracompact system. IMPO is a self-contained blood pump and oxygenator assembly to enable rapid deployment for patients requiring respiratory support or circulatory support. In this study, computational fluid dynamics (CFD) and computer-aided design were conducted to design and optimize the hemodynamics, gas transfer, and hemocompatibility performances of this novel device. In parallel, in vitro experiments including hydrodynamic, gas transfer, and hemolysis measurements were conducted to evaluate the performance of IMPO. Computational results from CFD analysis were compared with experimental data collected from in vitro evaluation of the IMPO. The CFD simulation demonstrated a well-behaved and streamlined flow field in the main components of this device. The results of hydrodynamic performance, oxygen transfer, and hemolysis predicted by computational simulation, along with the in vitro experimental data, indicate that this pump-lung device can provide the total respiratory need of an adult with lung failure, with a low hemolysis rate at the targeted operating condition. These detailed CFD designs and analyses can provide valuable guidance for further optimization of this IMPO for long-term use.

Effectiveness of a personalized device in the evaluation of mandibular second molar periodontal healing after surgical extraction of adjacent third molar

PubMed Central

Pippi, Roberto

2013-01-01

Summary Aim The primary aim of the present study was to validate the effectiveness of a personalized device able to guide periodontal probing in evaluation of second molar periodontal healing after adjacent third molar surgical extraction. Secondarily, the study analyzed if any patient and tooth related factors affected the second molar periodontal healing as well as if they were able to affect the periodontal probing depth performed with or without the personalized device. Materials and methods Thirty-five lower second molars were evaluated after extraction of the adjacent third molar. Pre-operative as well as 3 and 12 month post-operative probing depths of the distal surface of the second molar were evaluated. All measurements were taken by two different methods: standard two-point and four-point probing using a personalized onlay-type guide. Periapical radiographs were also evaluated. The Pearson product moment and the general linear model with backward stepwise procedure were used for inferential statistics. Results The mean 12-month post-operative probing depth/mean pre-operative probing depth ratio obtained with the guided probing method showed a highly significant effect on the 12-month radiographic post-operative/pre-operative radiographic measure ratio. None of the examined patient- or tooth-related factors showed a significant effect on pre-operative/12-month post-operative radiographic measure ratio. Conclusions The use of the proposed personalized device seems to provide a more reliable estimate of second molar periodontal healing after adjacent third molar surgical extraction. No patient-or tooth-related factors seem to be able to affect either second molar periodontal healing or probing depth measures obtained with or without the personalized device in individuals younger than 25 years old. It can be therefore recommended that lower third molar surgical extraction be performed in young adults. PMID:24611086

The STENTYS self-apposing stent technology in coronary artery disease: literature review and future directions.

PubMed

Lu, Huangling; de Winter, Robbert J; Koch, Karel T

2018-06-21

Coronary stent designs have been through extensive developments in the past few decades. Since the first introduction of the self-apposing STENTYS stent, several theoretical advantages of its nitinol platform have been clinically evaluated. This paper reviews the current status, ongoing work and future directions of this device. Areas covered: The OPEN (STENTYS Coronary Bifurcation Stent System fOr the PErcutaNeous treatment of de novo lesions in native bifurcated coronary arteries) trials revealed high technical success rates of the STENTYS performance in bifurcation lesions. The APPOSITION (Assessment of the Safety and Performance of the STENTYS self-expanding Coronary Stent in Acute Myocardial Infarction) trials demonstrated the safety and feasibility of the device in patients with acute myocardial infarction. Optical coherence tomography showed better short-term strut apposition in patients treated with the STENTYS stent in APPOSITION IV. The clinical outcomes of the device in saphenous vein graft lesions and left main coronary artery disease are favourable. Expert Commentary: Despite numerous theoretical advantages of the nitinol platform, superiority of the STENTYS self-apposing stent over currently available DES has not yet been proven. However, the ongoing registries evaluating the performance of the STENTYS Xposition will provide more insights in its clinical performance.

Long-term Results for the BacJac Interspinous Device in Lumbar Spine Degenerative Disease.

PubMed

Spallone, Aldo; Lavorato, Luigi; Belvisi, Daniele

2018-05-14

 To evaluate the long-term results of using the BacJac interspinous device (Pioneer Surgical Technology Inc.) in a series of patients with degenerative lumbar spine disease.  Forty-one patients undergoing lumbar surgery with implantation of a BacJac device from 2009 to 2012 were enrolled in the present study. Patients were evaluated using the Oswestry Disability Scale (ODI).  Although all patients showed a significant improvement of the ODI score immediately after surgery, only 41% of patients showed a satisfactory outcome. We observed worse results in the patients operated on at the L3-L4 level and in whom the device was implanted in a segment different from the one where surgical decompression had been performed. Weight gain in the months after surgery was also a poor outcome-influencing factor.  This study confirms what is already suggested in the relevant literature regarding the long-term inefficacy of the so-called dynamic stabilization devices. Georg Thieme Verlag KG Stuttgart · New York.

Field Evaluations of Tracking/Locating Technologies for Prevention of Missing Incidents.

PubMed

Bulat, Tatjana; Kerrigan, Michael V; Rowe, Meredeth; Kearns, William; Craighead, Jeffrey D; Ramaiah, Padmaja

2016-09-01

Persons with dementia are at risk of a missing incident, which is defined as an instance in which a demented person's whereabouts are unknown to the caregiver and the individual is not in an expected location. Since it is critical to determine the missing person's location as quickly as possible, we evaluated whether commercially available tracking technologies can assist in a rapid recovery. This study examined 7 commercially available tracking devices: 3 radio frequency (RF) based and 4 global positioning system (GPS) based, employing realistic tracking scenarios. Outcome measures were time to discovery and degree of deviation from a straight intercept course. Across all scenarios tested, GPS devices were found to be approximately twice as efficient as the RF devices in locating a "missing person." While the RF devices showed reasonable performance at close proximity, the GPS devices were found to be more appropriate overall for tracking/locating missing persons over unknown and larger distances. © The Author(s) 2016.

Design of a haptic device with grasp and push-pull force feedback for a master-slave surgical robot.

PubMed

Hu, Zhenkai; Yoon, Chae-Hyun; Park, Samuel Byeongjun; Jo, Yung-Ho

2016-07-01

We propose a portable haptic device providing grasp (kinesthetic) and push-pull (cutaneous) sensations for optical-motion-capture master interfaces. Although optical-motion-capture master interfaces for surgical robot systems can overcome the stiffness, friction, and coupling problems of mechanical master interfaces, it is difficult to add haptic feedback to an optical-motion-capture master interface without constraining the free motion of the operator's hands. Therefore, we utilized a Bowden cable-driven mechanism to provide the grasp and push-pull sensation while retaining the free hand motion of the optical-motion capture master interface. To evaluate the haptic device, we construct a 2-DOF force sensing/force feedback system. We compare the sensed force and the reproduced force of the haptic device. Finally, a needle insertion test was done to evaluate the performance of the haptic interface in the master-slave system. The results demonstrate that both the grasp force feedback and the push-pull force feedback provided by the haptic interface closely matched with the sensed forces of the slave robot. We successfully apply our haptic interface in the optical-motion-capture master-slave system. The results of the needle insertion test showed that our haptic feedback can provide more safety than merely visual observation. We develop a suitable haptic device to produce both kinesthetic grasp force feedback and cutaneous push-pull force feedback. Our future research will include further objective performance evaluations of the optical-motion-capture master-slave robot system with our haptic interface in surgical scenarios.

The Measurement of Airflow Using Singing Helmet That Allows Free Movement of the Jaw.

PubMed

Jiang, Jack J; Hanna, Rewais B; Willey, Malachi V; Rieves, Adam

2016-11-01

Airflow measurement is a useful method of evaluating laryngeal physiology. We introduce a noninvasive device that measures airflow without restricting jaw movement or requiring phonation into a mouthpiece, thus facilitating measurement during singing and connected speech. Validation and human subject trials were conducted. Airflow measurements were obtained from 16 male and 16 female subjects during singing, speech, and constant vowel production tasks. A similar helmet was designed by Stevens and Mead in 1968. The new device validity was evaluated by comparing the measured volume of air to a known volume of administered air using a calibration syringe. Subjects were asked to voice sustained vowels at low, medium, and high vocal intensity, read two sentences at a conversational volume, and perform different singing exercises while airflow was recorded. The device accurately and reliably measured airflow with mean airflow values falling within previously published ranges. There was an experimentally determined response time of 0.173 ± 0.014 seconds. Subjects were able to comfortably perform speech and singing exercises. Male subjects had higher airflow for all sustained vowels (P < 0.05). Airflow was higher for abduction rather than adduction sentences (P < 0.05). No other portable device has been shown to measure airflow during singing and speech while allowing for free movement of the jaw. This device provides a more natural environment to measure airflow that could be used to help evaluate laryngeal function and aid in singing training. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

E-Pad: a comfortable electrocutaneous-based tactile feedback display

NASA Astrophysics Data System (ADS)

Wang, Jiabin; Zhao, Lu; Liu, Yue; Wang, Yongtian; Cai, Yi

2018-01-01

The devices with touchscreen are becoming more popular recently; however, most of them suffer from the crucial drawbacks of lacking accurate tactile feedback. A novel electrocutaneous-based tactile device with the name of E-pad is proposed to provide a dynamic and static low-voltage feedback for touchscreen. We optimize the key parameters of the output voltage and design custom-made hardwares to guarantee a comfortable user experience. Users could move their fingers freely across the touchscreen of the proposed device to really feel virtual objects. Two preliminary experiments are conducted to evaluate the interactive performance of the proposed device and the experimental results show that the proposed device can provide a comfortable and distinct tactile feedback.

Evaluation results of xTCA equipment for HEP experiments at CERN

NASA Astrophysics Data System (ADS)

Di Cosmo, M.; Bobillier, V.; Haas, S.; Joos, M.; Mico, S.; Vasey, F.; Vichoudis, P.

2013-12-01

The MicroTCA and AdvancedTCA industry standards are candidate modular electronic platforms for the upgrade of the current generation of high energy physics experiments. The PH-ESE group at CERN launched in 2011 the xTCA evaluation project with the aim of performing technical evaluations and eventually providing support for commercially available components. Different devices from different vendors have been acquired, evaluated and interoperability tests have been performed. This paper presents the test procedures and facilities that have been developed and focuses on the evaluation results including electrical, thermal and interoperability aspects.

Development of an Optical Device to Investigatechlorophyll Content of Tomato Leaves

NASA Astrophysics Data System (ADS)

Cui, Di; Li, Minzan; Li, Xiuhua

Chlorophyll content is an important indication for evaluating crop growth status and predicting crop yield. The NDVI (Normalized Difference Vegetation Index) is commonly used as an indicator in practical crop healthy monitoring. Hence, a spectroscopy-based device for indirectly measuring crop growth conditions in terms of NDVI is developed. This device consists of four channels: two are designed to measure the intensity of the sunlight and the other two are used to measure the reflected light from the crop canopy at the same time. An electronic control unit was designed to control the sensing and data recording processes, as well as to calculate the NDVI based on the sensed data. The measurable two wavelengths are 610 nm and 1220 nm. A series validation tests, comparing the measurement result against spectroradiometer readings, are conducted to evaluate the performance of the device. Leaf samples are collected to measure chlorophyll contents in laboratory. The correlation coefficient between the NDVI readings from the developed device and the chlorophyll content data measured by the UV-VIS Spectrophotometer reaches 0.81, which shows that the device can be used in practical crop management.

Prosthetic Jamming Terminal Device: A Case Study of Untethered Soft Robotics

PubMed Central

Amend, John; Farrell, Todd; Latour, Debra; Martinez, Carlos; Johansson, Jen; McNicoll, Anthony; Wartenberg, Marek; Naseef, Samuel; Hanson, William; Culley, William

2016-01-01

Abstract This article illuminates the major and often overlooked challenge of untethering soft robotic systems through the context of recent work, in which soft robotic gripper technology enabled by jamming of granular media was applied to a prosthetic jamming terminal device (PJTD). The PJTD's technical and market feasibility was evaluated in a pilot study with two upper-limb amputees. A PJTD prototype was tested against a commercial device (Motion Control electric terminal service with a one degree-of-freedom pinching mechanism) using two existing hand function tests: the first quantified the device's speed in picking and placing small blocks and the second evaluated a person's ability to perform activities of daily living (ADLs). The PJTD prototype performed slightly slower than its commercial counterpart in the first test. While both participants successfully completed all the ADLs with both devices in the second test, the commercial device scored marginally higher. Results suggested that PJTD can have potential benefits over existing terminal devices, such as providing the capability to firmly grasp tools due to the ability of PJTD to conform to arbitrary surfaces and reducing compensatory shoulder movements due to its axisymmetric design. Some downsides were that users reported fatigue while operating the PJTD, as most operations require pushing the PJTD against target objects to adequately conform to them. The greatest drawback for the PJTD is also a major roadblock preventing a number of soft robotic research projects from making an impact in real-world applications: pneumatic technology required for operating the PJTD is currently too large and heavy to enable compact untethered operation. PMID:28078196

Performance evaluation of household water treatment systems used in Kerman for removal of cations and anions from drinking water

NASA Astrophysics Data System (ADS)

Malakootian, Mohammad; Amirmahani, Najmeh; Yazdanpanah, Ghazal; Nasiri, Alireza; Asadipour, Ali; Ebrahimi, Ahmad; Darvish Moghaddam, Sodaif

2017-12-01

Increased awareness in society of the consequences of contaminants in drinking water has created a demand for household water treatment systems, which provide higher quality water, to spread. The aim of this study was to evaluate the performance of household water treatment systems used in Kerman for the removal of cations and anions. Various brands of home water treatment devices commonly used in Kerman were selected, with one device chosen from each brand for study. In cases in which the devices were used extensively, samples were selected with filters that had been changed in proper time, based on the device's operational instructions. The samples were selected from homes in the center and four geographical directions of Kerman. Then, sampling was conducted in three stages of input and output water of each device. For each of the samples, parameters were measured, such as chloride, sulfate, bicarbonate, calcium, magnesium, hardness, sodium, nitrate and nitrite (mg/L), temperature (°C), and pH. The average removal efficiency of different parameters by 14 brands in Kerman, which include chloride ions, sulfate, bicarbonate, calcium, magnesium, sodium, nitrites, nitrates, and total hardness, was obtained at 68.48, 85, 67, 61.21, 78.97, 80.24, 32.59, 66.83, and 69.38%, respectively. The amount of sulfate, bicarbonate, chloride, calcium, magnesium, hardness, sodium, and nitrate in the output water of household water treatment systems was less than the input water of these devices, but nitrite concentration in the output of some devices was more than the input water and showed a significant difference ( p > 0.05).

Technical feasibility of personalized articulating knee joint distraction for treatment of tibiofemoral osteoarthritis.

PubMed

Struik, T; Jaspers, J E N; Besselink, N J; van Roermund, P M; Plomp, S; Rudert, M J; Lafeber, F P J G; Mastbergen, S C

2017-11-01

Knee osteoarthritis is a highly prevalent degenerative joint disorder characterized by joint tissue damage and pain. Knee joint distraction has been introduced as a joint preserving surgical procedure to postpone knee arthroplasty. An often used standard externally fixation device for distraction poses a burden to patients due to the absence of joint flexion during the 6weeks treatment. Therefore, a personalized articulating distraction device was developed. The aim of this study was to test technical feasibility of this device. Based on an often applied rigid device, using equal bone pin positions and connectors, a hinge mechanism was developed consisting of a cam-following system for reproducing the complex joint-specific knee kinematics. In support, a device was developed for capturing the joint-specific sagittal plane articulation. The obtained kinematic data were translated into joint-specific cam shapes that were installed bilaterally in the hinge mechanism of the distraction device, as such providing personalized knee motion. Distraction of 5mm was performed within a range of motion of 30deg. joint flexion. Pre-clinical evaluation of the working principle was performed on human cadaveric legs and system stiffness characteristics were biomechanically evaluated. The desired range of motion was obtained and distraction was maintained under physiologically representative loading. Moreover, the joint-specific approach demonstrated tolerance of deviations from anatomical and alignment origin during initial placement of the developed distraction device. Articulation during knee distraction is considered technically feasible and has potential to decrease burden and improve acceptance of distraction therapy. Testing of clinical feasibility is warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

Turning a cylindrical treadmill with feet: an MR-compatible device for assessment of the neural correlates of lower-limb movement.

PubMed

Toyomura, Akira; Yokosawa, Koichi; Shimojo, Atsushi; Fujii, Tetsunoshin; Kuriki, Shinya

2018-06-17

Locomotion, which is one of the most basic motor functions, is critical for performing various daily-life activities. Despite its essential function, assessment of brain activity during lower-limb movement is still limited because of the constraints of existing brain imaging methods. Here, we describe an MR-compatible, cylindrical treadmill device that allows participants to perform stepping movements on an MRI scanner table. The device was constructed from wood and all of the parts were handmade by the authors. We confirmed the MR-compatibility of the device by evaluating the temporal signal-to-noise ratio of 64 voxels of a phantom during scanning. Brain activity was measured while twenty participants turned the treadmill with feet in sync with metronome sounds. The rotary speed of the cylinder was encoded by optical fibers. The post/pre-central gyrus and cerebellum showed significant activity during the movements, which was comparable to the activity patterns reported in previous studies. Head movement on the y- and z-axes was influenced more by lower-limb movement than was head movement on the x-axis. Among the 60 runs (3 runs × 20 participants), head movement during two of the runs (3.3%) was excessive due to the lower-limb movement. Compared to MR-compatible devices proposed in the previous studies, the advantage of this device may be simple structure and replicability to realize stepping movement with a supine position. Collectively, our results suggest that the treadmill device is useful for evaluating lower-limb-related neural activity. Copyright © 2018. Published by Elsevier B.V.

Cost analysis of medical device spare parts

PubMed Central

Bektemur, Guven; Muzoglu, Nedim; Arici, Mehmet Ali; Karaaslan, Melike Kaya

2018-01-01

Objective: To establish estimation method on budget management of medical device spare parts and to evaluate the cost of medical device spare parts in affiliated hospitals of Istanbul Public Hospital Unions (PHUs). Methods: While this evaluation was performed, the relationship between paid cost for spare parts according to technological development level of device groups and total inventory value was used. Spare part cost analysis was carried out by using the normalized weighted arithmetic average method. Cost analysis of medical equipment spare parts of Istanbul PHUs was performed by using the data retrieved from Ministry of Health Business Intelligence Decision Support System for spending of spare parts in 2015. Results: The medical device spare part groups were categorized based on technological development. Among 1 to 6 PHUs, the cost ratios were acquired for high, middle, low and simple technology group as 17.31 – 40.08%, 29.14 – 43.36%, 22.62 – 27.44% and 8.16 – 11.89%, respectively. The ratio between the spare part and total inventory costs for 1-6 PHUs were calculated as 1.66%, 2.87%, 3.03%, 3.31%, 2.57% and 4.69% respectively. Expected rates based on normalized weighted method were obtained as follows; 5.76%, 4.67%, 5.31%, 4.87%, 4.34% and 4.27%. Conclusion: The expenditure analysis and budget planning for medical device spare parts in PHU could be predicted more accurately by taking into consideration the expected rate calculated by the normal weight method. In additon, the importance of Clinical Engineering Service Units in management of medical devices has been determined. PMID:29805429

Practice of Regulatory Science (Development of Medical Devices).

PubMed

Niimi, Shingo

2017-01-01

Prototypes of medical devices are made in accordance with the needs of clinical practice, and for systems required during the initial process of medical device development for new surgical practices. Verification of whether these prototypes produce the intended performance specifications is conducted using basic tests such as mechanical and animal tests. The prototypes are then improved and modified until satisfactory results are obtained. After a prototype passes through a clinical trial process similar to that for new drugs, application for approval is made. In the approval application process, medical devices are divided into new, improved, and generic types. Reviewers judge the validity of intended use, indications, operation procedures, and precautions, and in addition evaluate the balance between risk and benefit in terms of efficacy and safety. Other characteristics of medical devices are the need for the user to attain proficiency in usage techniques to ensure efficacy and safety, and the existence of a variety of medical devices for which assessment strategies differ, including differences in impact on the body in cases in which a physical burden to the body or failure of a medical device develops. Regulatory science of medical devices involves prediction, judgment, and evaluation of efficacy, safety, and quality, from which data result which can become indices in the development stages from design to application for approval. A reduction in the number of animals used for testing, improvement in efficiency, reduction of the necessity for clinical trials, etc. are expected through rational setting of evaluation items.

Medical Device for Automated Prick Test Reading.

PubMed

Justo, Xabier; Diaz, Inaki; Gil, Jorge Juan; Gastaminza, Gabriel

2018-05-01

Allergy tests are routinely performed in most hospitals everyday. However, measuring the outcomes of these tests is still a very laborious manual task. Current methods and systems lack of precision and repeatability. This paper presents a novel mechatronic system that is able to scan a patient's entire arm and provide allergists with precise measures of wheals for diagnosis. The device is based on 3-D laser technology and specific algorithms have been developed to process the information gathered. This system aims to automate the reading of skin prick tests and make gains in speed, accuracy, and reliability. Several experiments have been performed to evaluate the performance of the system.

The cell engineering construction and function evaluation of multi-layer biochip dialyzer.

PubMed

Zhu, Wen; Li, Jiwei; Liu, Jianfeng

2013-10-01

We report the fabrication and function evaluation of multi-layer biochip dialyzer. Such device may potentially be applied to the wearable hemodialysis systems. By merging the advantages of microfluidic chip technology with cell engineering, both functions of glomerular filtration and renal tubule physiological activity are integrated in the same device. This device is designed into a laminated structure, in which the chip number of the superimposed layer can be arbitrarily tailored in accordance with the requirements of dialysis capacity. We propose that such structure can overcome the obstacles of large size and detached structure of the traditional hollow fiber dialyzer. To construct this multilayer biochips dialyzer, two types of dialyzer device with two-layered and six-layered chips are assembled, respectively. Cell adhesion and proliferation on three different dialysis membrane materials under static and dynamic conditions are investigated and compared. The filtration capability, re-absorption function and excrete ammonia function of the resulting multi-layer biochip dialyzer are evaluated. The results reveal that the constructed device can perform higher filtration efficiency and also play a role of renal tubule. This methodology may be useful in developing "scaling down" artificial kidneys that can act as wearable or even implantable hemodialysis systems.

Characterization and outcomes of reinterventions in Food and Drug Administration-approved versus trial endovascular aneurysm repair devices.

PubMed

Fairman, Alexander S; Wang, Grace J; Jackson, Benjamin M; Foley, Paul J; Damrauer, Scott M; Kalapatapu, Venkat; Golden, Michael A; Fairman, Ronald M

2018-04-01

Published rates of reintervention after endovascular aneurysm repair (EVAR) range from 10% to 30%. We evaluated a single university center's experience with reinterventions in the context of Food and Drug Administration (FDA)-approved and trial devices. Retrospective data collection was performed for patients who underwent infrarenal EVAR and required reintervention from 2000 to 2016. Trial devices included those used in FDA feasibility and pivotal trials. Time-to-event analysis was performed using Cox regression. Predictors of mortality and explantation were evaluated using logistic regression; survival analysis was performed using Kaplan-Meier methods. From 2000 to 2016, there were 1835 EVARs performed, and 137 patients (116 men; mean age, 72.2 ± 10.0 years) underwent reintervention with a mean aneurysm size of 5.9 ± 1.2 cm. The median follow-up was 5 years with an overall survival of 70.1%. The overall reintervention rate was 7.5%. FDA-approved devices had a reintervention rate of 6.4%, whereas trial devices had a rate of 14.4% (P < .001). For all devices, the most common cause of reintervention was type II endoleak (52.5%), followed by type I endoleak (18.2%), type III endoleak (9.5%), limb kink (7.3%), iliac occlusive disease (5.8%), endotension (1.5%), and other. The overall mean time to first reintervention was 2.3 ± 2.5 years, and univariate Cox regression identified male gender (hazard ratio, 1.91; 95% confidence interval [CI], 1.17-3.10; P = .010) and age at the time of EVAR (hazard ratio, 1.03; 95% CI, 1.01-1.05; P = .006) as risk factors for time to first reintervention. Among patients requiring reintervention, the mean number of reinterventions for trial devices was significantly greater than that for FDA-approved devices (2.18 vs 1.65; P = .01). Trial devices requiring reintervention had a nearly threefold higher odds for the need for more than two reinterventions (odds ratio, 2.88; 95% CI, 1.12-7.37; P = .034). Trial device, cause of reintervention, and type of reintervention were not predictive of the need for explantation or mortality, but the number of reinterventions was significantly associated with the need for explantation (odds ratio, 1.86; 95% CI, 1.17-2.96; P = .012). EVAR device and the need for explantation did not have an impact on mortality. Despite the rigorous nature of patient enrollment in clinical trials and the development of newer iterations of investigational devices, patients undergoing EVAR with trial devices are more likely to undergo a greater number of reinterventions than with FDA-approved devices. Although mortality and the need for explantation were not significantly associated with trial devices, the finding of a greater number of reinterventions highlights the need to properly inform patients willing to partake in investigational device trials. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Comparison of four commercial devices for RapidArc and sliding window IMRT QA

PubMed Central

Chandraraj, Varatharaj; Manickam, Ravikumar; Esquivel, Carlos; Supe, Sanjay S.; Papanikolaou, Nikos

2011-01-01

For intensity‐modulated radiation therapy, evaluation of the measured dose against the treatment planning calculated dose is essential in the context of patient‐specific quality assurance. The complexity of volumetric arc radiotherapy delivery attributed to its dynamic and synchronization nature require new methods and potentially new tools for the quality assurance of such techniques. In the present study, we evaluated and compared the dosimetric performance of EDR2 film and three other commercially available quality assurance devices: IBA I'MatriXX array, PTW Seven29 array and the Delta 4 array. The evaluation of these dosimetric systems was performed for RapidArc and IMRT deliveries using a Varian NovalisTX linear accelerator. The plans were generated using the Varian Eclipse treatment planning system. Our results showed that all four QA techniques yield equivalent results. All patient QAs passed our institutional clinical criteria of gamma index based on a 3% dose difference and 3 mm distance to agreement. In addition, the Bland‐Altman analysis was performed which showed that all the calculated gamma values of all three QA devices were within 5% from those of the film. The results showed that the four QA systems used in this patient‐specific IMRT QA analysis are equivalent. We concluded that the dosimetric systems under investigation can be used interchangeably for routine patient specific QA. PACS numbers: 87.55.Qr, 87.56.Fc

Preclinical evaluation of the effect of the combined use of the Ethicon Securestrap® Open Absorbable Strap Fixation Device and Ethicon Physiomesh™ Open Flexible Composite Mesh Device on surgeon stress during ventral hernia repair

PubMed Central

Sutton, Nadia; MacDonald, Melinda H; Lombard, John; Ilie, Bodgan; Hinoul, Piet; Granger, Douglas A

2018-01-01

Aim To evaluate whether performing ventral hernia repairs using the Ethicon Physiomesh™ Open Flexible Composite Mesh Device in conjunction with the Ethicon Securestrap® Open Absorbable Strap Fixation Device reduces surgical time and surgeon stress levels, compared with traditional surgical repair methods. Methods To repair a simulated ventral incisional hernia, two surgeries were performed by eight experienced surgeons using a live porcine model. One procedure involved traditional suture methods and a flat mesh, and the other procedure involved a mechanical fixation device and a skirted flexible composite mesh. A Surgery Task Load Index questionnaire was administered before and after the procedure to establish the surgeons’ perceived stress levels, and saliva samples were collected before, during, and after the surgical procedures to assess the biologically expressed stress (cortisol and salivary alpha amylase) levels. Results For mechanical fixation using the Ethicon Physiomesh Open Flexible Composite Mesh Device in conjunction with the Ethicon Securestrap Open Absorbable Strap Fixation Device, surgeons reported a 46.2% reduction in perceived workload stress. There was also a lower physiological reactivity to the intraoperative experience and the total surgical procedure time was reduced by 60.3%. Conclusions This study provides preliminary findings suggesting that the combined use of a mechanical fixation device and a skirted flexible composite mesh in an open intraperitoneal onlay mesh repair has the potential to reduce surgeon stress. Additional studies are needed to determine whether a reduction in stress is observed in a clinical setting and, if so, confirm that this results in improved clinical outcomes. PMID:29296101

Advancing the Technology of Monolithic CMOS detectors for their use as X-ray Imaging Spectrometers

NASA Astrophysics Data System (ADS)

Kenter, Almus

The Smithsonian Astrophysical Observatory (SAO) proposes a two year program to further advance the scientific capabilities of monolithic CMOS detectors for use as x-ray imaging spectrometers. This proposal will build upon the progress achieved with funding from a previous APRA proposal that ended in 2013. As part of that previous proposal, x- ray optimized, highly versatile, monolithic CMOS imaging detectors and technology were developed and tested. The performance and capabilities of these devices were then demonstrated, with an emphasis on the performance advantages these devices have over CCDs and other technologies. The developed SAO/SRI-Sarnoff CMOS devices incorporate: Low noise, high sensitivity ("gain") pixels; Highly parallel on-chip signal chains; Standard and very high resistivity (30,000Ohm-cm) Si; Back-Side thinning and passivation. SAO demonstrated the performance benefits of each of these features in these devices. This new proposal high-lights the performance of this previous generation of devices, and segues into new technology and capability. The high sensitivity ( 135uV/e) 6 Transistor (6T) Pinned Photo Diode (PPD) pixels provided a large charge to voltage conversion gain to the detect and resolve even small numbers of photo electrons produced by x-rays. The on-chip, parallel signal chain processed an entire row of pixels in the same time that a CCD requires to processes a single pixel. The resulting high speed operation ( 1000 times faster than CCD) provide temporal resolution while mitigating dark current and allowed room temperature operation. The high resistivity Si provided full (over) depletion for thicker devices which increased QE for higher energy x-rays. In this proposal, SAO will investigate existing NMOS and existing PMOS devices as xray imaging spectrometers. Conventional CMOS imagers are NMOS. NMOS devices collect and measure photo-electrons. In contrast, PMOS devices collect and measure photo-holes. PMOS devices have various attributes that would make them superior for use in X-ray astronomy. In particular, PMOS has: "no" photo-charge recombination; "no" Random Telegraph Signal noise (RTS); and lower read noise. The existing SRI/Sarnoff PMOS devices are small and have been developed for non-intensified night vision applications, however, no x-ray evaluation of a monolithic PMOS device has ever been made. In addition to these PMOS devices, SAO will also evaluate existing NMOS scale-able format devices that can be fabricated in any rectangular size/shape using stitchable reticles. These "Mk by Nk" devices would be ideal for large X-ray focal planes or long grating readouts. The Sarnoff/SRI Mk by Nk format devices have been designed, with foresight, so that they can be fabricated in either PMOS or NMOS by changing a single fabrication reticle and by changing the type of Si substrate. If X-ray performance results are expected, this proposal will lead the way to future fabrication of Mk by Nk PMOS devices that would be ideal for X-ray astronomy missions such as "X-ray Surveyor". SAO will also investigate the interaction of directly deposited Optical Blocking Filters (OBFs) on various back side passivated devices, and their resultant effects on very "soft" x-ray response. The latest CMOS processes and very fast on-chip, and off-chip digital readout signal chains and camera systems will be demonstrated.

Guidelines for point-of-care testing: haematology.

PubMed

Briggs, Carol; Guthrie, David; Hyde, Keith; Mackie, Ian; Parker, Norman; Popek, Mary; Porter, Neil; Stephens, Clare

2008-09-01

This guideline provides a framework for the arrangement of point-of-care testing (POCT) services, previously known as near patient testing (patient self-testing not covered). POCT is defined as any analytical test performed outside the laboratory. Primary users are often non-laboratory healthcare workers. The guidance applies to units within hospitals as well as general practioner surgeries, community clinics and pharmacies. The head of the haematology laboratory or a point of care coordinator must take responsibility for all aspects of the POCT service, including quality and training. Depending on the size and nature of the POCT practice, a local POCT manager may also be required. Equipment selected should have received a successful independent performance evaluation. If an independent evaluation has not been performed the purchaser should assess the device according to the protocol in this document. POCT devices should generate results that are comparable to those of the local laboratory. An accredited external quality assessment programme and internal quality control system must be established. Manufacturers promoting POCT devices designed for non-laboratory sites, e.g. pharmacies, should undertake training and annual competency assessment, perhaps using a web-based system. A diagram to illustrate the stages for the implementation of a POCT service is illustrated.

Implantable centrifugal blood pump with dual impeller and double pivot bearing system: electromechanical actuator, prototyping, and anatomical studies.

PubMed

Bock, Eduardo; Antunes, Pedro; Leao, Tarcisio; Uebelhart, Beatriz; Fonseca, Jeison; Leme, Juliana; Utiyama, Bruno; da Silva, Cibele; Cavalheiro, Andre; Filho, Diolino Santos; Dinkhuysen, Jarbas; Biscegli, Jose; Andrade, Aron; Arruda, Celso

2011-05-01

An implantable centrifugal blood pump has been developed with original features for a left ventricular assist device. This pump is part of a multicenter and international study with the objective to offer simple, affordable, and reliable devices to developing countries. Previous computational fluid dynamics investigations and wear evaluation in bearing system were performed followed by prototyping and in vitro tests. In addition, previous blood tests for assessment of normalized index of hemolysis show results of 0.0054±2.46 × 10⁻³ mg/100 L. An electromechanical actuator was tested in order to define the best motor topology and controller configuration. Three different topologies of brushless direct current motor (BLDCM) were analyzed. An electronic driver was tested in different situations, and the BLDCM had its mechanical properties tested in a dynamometer. Prior to evaluation of performance during in vivo animal studies, anatomical studies were necessary to achieve the best configuration and cannulation for left ventricular assistance. The results were considered satisfactory, and the next step is to test the performance of the device in vivo. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

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

Smith, Leon E.; Conrad, Ryan C.; Keller, Daniel T.

The International Atomic Energy Agency (IAEA) deploys unattended monitoring systems to provide continuous monitoring of nuclear material within safeguarded facilities around the world. As the number of unattended monitoring instruments increases, the IAEA is challenged to become more efficient in the implementation of those systems. In 2010, the IAEA initiated the Front-End Electronics for Unattended Measurement (FEUM) project with the goals of greater flexibility in the interfaces to various sensors and data acquisition systems, and improved capabilities for remotely located sensors (e.g., where sensor and front-end electronics might be separated by tens of meters). In consultation with the IAEA, amore » technical evaluation of a candidate FEUM device produced by a commercial vendor is being performed. This evaluation is assessing the device against the IAEA’s original technical specifications and a broad range of important parameters that included sensor types, cable types, and industrial electromagnetic noise that can degrade signals from remotely located detectors. Testing has been performed in a laboratory and also in environments representative of IAEA deployments. The results are expected to inform the IAEA about where and how FEUM devices might be implemented in the field. Data and preliminary findings from the testing performed to date are presented.« less

Enhanced Lifetime of Polymer Solar Cells by Surface Passivation of Metal Oxide Buffer Layers.

PubMed

Venkatesan, Swaminathan; Ngo, Evan; Khatiwada, Devendra; Zhang, Cheng; Qiao, Qiquan

2015-07-29

The role of electron selective interfaces on the performance and lifetime of polymer solar cells were compared and analyzed. Bilayer interfaces consisting of metal oxide films with cationic polymer modification namely poly ethylenimine ethoxylated (PEIE) were found to enhance device lifetime compared to bare metal oxide films when used as an electron selective cathode interface. Devices utilizing surface-modified metal oxide layers showed enhanced lifetimes, retaining up to 85% of their original efficiency when stored in ambient atmosphere for 180 days without any encapsulation. The work function and surface potential of zinc oxide (ZnO) and ZnO/PEIE interlayers were evaluated using Kelvin probe and Kelvin probe force microscopy (KPFM) respectively. Kelvin probe measurements showed a smaller reduction in work function of ZnO/PEIE films compared to bare ZnO films when aged in atmospheric conditions. KPFM measurements showed that the surface potential of the ZnO surface drastically reduces when stored in ambient air for 7 days because of surface oxidation. Surface oxidation of the interface led to a substantial decrease in the performance in aged devices. The enhancement in the lifetime of devices with a bilayer interface was correlated to the suppressed surface oxidation of the metal oxide layers. The PEIE passivated surface retained a lower Fermi level when aged, which led to lower trap-assisted recombination at the polymer-cathode interface. Further photocharge extraction by linearly increasing voltage (Photo-CELIV) measurements were performed on fresh and aged samples to evaluate the field required to extract maximum charges. Fresh devices with a bare ZnO cathode interlayer required a lower field than devices with ZnO/PEIE cathode interface. However, aged devices with ZnO required a much higher field to extract charges while aged devices with ZnO/PEIE showed a minor increase compared to the fresh devices. Results indicate that surface modification can act as a suitable passivation layer to suppress oxidation in metal oxide thin films for enhanced lifetime in inverted organic solar cells.

A Device for Local or Remote Monitoring of Hand Rehabilitation Sessions for Rheumatic Patients

PubMed Central

Barabino, Gianluca; Dessì, Alessia; Tradori, Iosto; Piga, Matteo; Mathieu, Alessandro; Raffo, Luigi

2014-01-01

Current clinical practice suggests that recovering the hand functionality lost or reduced by injuries, interventions and chronic diseases requires, beyond pharmacological treatments, a kinesiotherapic intervention. This form of rehabilitation consists of physical exercises adapted to the specific pathology. Its effectiveness is strongly dependent on the patient's adhesion to such a program. In this paper we present a novel device with remote monitoring capabilities expressly conceived for the needs of rheumatic patients. It comprises several sensorized tools and can be used either in an outpatient clinic for hand functional evaluation, connected to a PC, or afforded to the patient for home kinesiotherapic sessions. In the latter case, the device guides the patient in the rehabilitation session, transmitting the relevant statistics about his performance to a TCP/IP server exploiting a GSM/GPRS connection for deferred analysis. An approved clinical trial has been set up in Italy, involving 10 patients with Rheumatoid Arthritis and 10 with Systemic Sclerosis, enrolled for 12 weeks in a home rehabilitation program with the proposed device. Their evaluation has been performed with traditional methods but also with the proposed device. Subjective (hand algofunctional Dreiser's index) and objective (ROM, strength, dexterity) parameters showed a sustained improvement throughout the follow-up. The obtained results proved that the device is an effective and safe tool for assessing hand disability and monitoring kinesiotherapy exercise, portending the potential exploitability of such a methodology in clinical practice. PMID:27170875

Respiratory monitoring system based on the nasal pressure technique for the analysis of sleep breathing disorders: Reduction of static and dynamic errors, and comparisons with thermistors and pneumotachographs

NASA Astrophysics Data System (ADS)

Alves de Mesquita, Jayme; Lopes de Melo, Pedro

2004-03-01

Thermally sensitive devices—thermistors—have usually been used to monitor sleep-breathing disorders. However, because of their long time constant, these devices are not able to provide a good characterization of fast events, like hypopneas. Nasal pressure recording technique (NPR) has recently been suggested to quantify airflow during sleep. It is claimed that the short time constants of the devices used to implement this technique would allow an accurate analysis of fast abnormal respiratory events. However, these devices present errors associated with nonlinearities and acoustic resonance that could reduce the diagnostic value of the NPR. Moreover, in spite of the high scientific and clinical potential, there is no detailed description of a complete instrumentation system to implement this promising technique in sleep studies. In this context, the purpose of this work was twofold: (1) describe the development of a flexible NPR device and (2) evaluate the performance of this device when compared to pneumotachographs (PNTs) and thermistors. After the design details are described, the system static accuracy is evaluated by a comparative analysis with a PNT. This analysis revealed a significant reduction (p<0.001) of the static error when system nonlinearities were reduced. The dynamic performance of the NPR system was investigated by frequency response analysis and time constant evaluations and the results showed that the developed device response was as good as PNT and around 100 times faster (τ=5,3 ms) than thermistors (τ=512 ms). Experimental results obtained in simulated clinical conditions and in a patient are presented as examples, and confirmed the good features achieved in engineering tests. These results are in close agreement with physiological fundamentals, supplying substantial evidence that the improved dynamic and static characteristics of this device can contribute to a more accurate implementation of medical research projects and to improve the diagnoses of sleep-breathing disorders.

Development and evaluation of a soft wearable weight support device for reducing muscle fatigue on shoulder

PubMed Central

Cho, Kyu-Jin

2017-01-01

Compensating the weight of human limbs is important in reducing muscle fatigue experienced by manual laborers. In this study, a compact and lightweight soft wearable weight support device was developed and evaluated. The device supports gravitational force on the shoulder at any arm posture, although there are some limitations in its assistive performance. The device actuator consists of a cam-rod structure, a tendon-driven mechanism, and a rubber band. The desired assistive torque is translated to the shoulder joint along a tendon routing structure. Device performance was evaluated by measuring muscle activation in with-assist and without-assist conditions. Muscle activation on the deltoid was measured by surface electromyography. An experimental protocol consisting of a series of exercises was executed with six healthy subjects. The subjects raised and lowered their arm from 0 to 100 degrees for 30 times under eight conditions, which were combined with-assist and without-assist conditions, and holding the horizontal angle of the arm at 0, 30, 60, or 90 degrees against the sagittal plane. Surface electromyography data were pre-processed and analyzed using a root mean square method. When muscle fatigue occurs, the root mean square of the surface electromyography increases nonlinearly. This was calculated using the standard deviation of the root mean square. Three of six subjects showed decreased variation of the root mean square between the exercises in the with-assist condition. One subject’s result was significantly reduced (by about 57.6%) in the with-assist condition. In contrast, two subjects did not show significant difference between measurements taken in the with-assist and without-assist conditions. One subject was dropped from the experiment because the device did not fit the subject’s body. In conclusion, the effectiveness of the soft wearable weight support device in supporting shoulder movements was verified through the decreased variation of muscle activation. PMID:28291825

Development and evaluation of a soft wearable weight support device for reducing muscle fatigue on shoulder.

PubMed

Park, Daegeun; Cho, Kyu-Jin

2017-01-01

Compensating the weight of human limbs is important in reducing muscle fatigue experienced by manual laborers. In this study, a compact and lightweight soft wearable weight support device was developed and evaluated. The device supports gravitational force on the shoulder at any arm posture, although there are some limitations in its assistive performance. The device actuator consists of a cam-rod structure, a tendon-driven mechanism, and a rubber band. The desired assistive torque is translated to the shoulder joint along a tendon routing structure. Device performance was evaluated by measuring muscle activation in with-assist and without-assist conditions. Muscle activation on the deltoid was measured by surface electromyography. An experimental protocol consisting of a series of exercises was executed with six healthy subjects. The subjects raised and lowered their arm from 0 to 100 degrees for 30 times under eight conditions, which were combined with-assist and without-assist conditions, and holding the horizontal angle of the arm at 0, 30, 60, or 90 degrees against the sagittal plane. Surface electromyography data were pre-processed and analyzed using a root mean square method. When muscle fatigue occurs, the root mean square of the surface electromyography increases nonlinearly. This was calculated using the standard deviation of the root mean square. Three of six subjects showed decreased variation of the root mean square between the exercises in the with-assist condition. One subject's result was significantly reduced (by about 57.6%) in the with-assist condition. In contrast, two subjects did not show significant difference between measurements taken in the with-assist and without-assist conditions. One subject was dropped from the experiment because the device did not fit the subject's body. In conclusion, the effectiveness of the soft wearable weight support device in supporting shoulder movements was verified through the decreased variation of muscle activation.

Evaluating color performance of whole-slide imaging devices by multispectral-imaging of biological tissues

NASA Astrophysics Data System (ADS)

Saleheen, Firdous; Badano, Aldo; Cheng, Wei-Chung

2017-03-01

The color reproducibility of two whole-slide imaging (WSI) devices was evaluated with biological tissue slides. Three tissue slides (human colon, skin, and kidney) were used to test a modern and a legacy WSI devices. The color truth of the tissue slides was obtained using a multispectral imaging system. The output WSI images were compared with the color truth to calculate the color difference for each pixel. A psychophysical experiment was also conducted to measure the perceptual color reproducibility (PCR) of the same slides with four subjects. The experiment results show that the mean color differences of the modern, legacy, and monochrome WSI devices are 10.94+/-4.19, 22.35+/-8.99, and 42.74+/-2.96 ▵E00, while their mean PCRs are 70.35+/-7.64%, 23.06+/-14.68%, and 0.91+/-1.01%, respectively.

Experiences with using a pushrim-activated power-assisted wheelchair for community-based occupations: a qualitative exploration.

PubMed

Giesbrecht, Ed M; Ripat, Jacquie D; Cooper, Juliette E; Quanbury, Arthur O

2011-04-01

Occupational therapists strive to engage individuals in occupation and enhance community access through wheelchair prescription. Previous research with pushrim-activated, power-assisted wheelchairs identifies a reduction in the physical demands of manual wheelchair propulsion but limited evidence exists regarding user evaluation in context. This study explored the experience of using a power-assisted wheelchair in the community. Eight individuals who used both a power and manual device participated in focus groups after trialing a power-assist wheelchair for three weeks. Data were analyzed using a qualitative description approach. Three themes emerged from our analysis: relative advantages and disadvantages; environmental factors that affect accessibility; and evaluation of mobility device. Participants perceived the power-assist as improving performance and accessibility compared with the manual wheelchair, increasing the potential scope of occupations and environments, but not replacing their power mobility device. Sufficient time for adjustment of both user and device was important.

Evaluation of the intercept oral specimen collection device with HIV assays versus paired serum/plasma specimens.

PubMed

Beelaert, G; Van Heddegem, L; Van Frankenhuijsen, M; Vandewalle, G; Compernolle, V; Florence, E; Fransen, K

2016-08-01

Oral fluid has many advantages over blood-based techniques: it is less invasive, eliminates the occupational risk associated with needle stick accidents and collection can be self-administrated. Each individual test is packaged with a corresponding collection device. This study tested the suitability of the Intercept Oral Specimen Collection Device for different HIV diagnostic tests: three different rapid HIV tests and two adapted ELISAs, which were evaluated and compared with a gold standard on blood. In addition a total IgG quantification was performed to demonstrate the quality of the specimen. HIV antibodies were detected with a sensitivity of 100%, 99.3%, 98.6%, 100% and 95.7% for, DPP, OraQuick, Aware, Genscreen and Vironostika respectively using the Intercept Collection Device. Respective specificities were 100%, 100%, 99.3%, 97.3% and 100%. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of a MEMS device for acoustic emission testing

NASA Astrophysics Data System (ADS)

Ozevin, Didem; Pessiki, Stephen P.; Jain, Akash; Greve, David W.; Oppenheim, Irving J.

2003-08-01

Acoustic emission testing is an important technology for evaluating structural materials, and especially for detecting damage in structural members. Significant new capabilities may be gained by developing MEMS transducers for acoustic emission testing, including permanent bonding or embedment for superior coupling, greater density of transducer placement, and a bundle of transducers on each device tuned to different frequencies. Additional advantages include capabilities for maintenance of signal histories and coordination between multiple transducers. We designed a MEMS device for acoustic emission testing that features two different mechanical types, a hexagonal plate design and a spring-mass design, with multiple detectors of each type at ten different frequencies in the range of 100 kHz to 1 MHz. The devices were fabricated in the multi-user polysilicon surface micromachining (MUMPs) process and we have conducted electrical characterization experiments and initial experiments on acoustic emission detection. We first report on C(V) measurements and perform a comparison between predicted (design) and measured response. We next report on admittance measurements conducted at pressures varying from vacuum to atmospheric, identifying the resonant frequencies and again providing a comparison with predicted performance. We then describe initial calibration experiments that compare the performance of the detectors to other acoustic emission transducers, and we discuss the overall performance of the device as a sensor suite, as contrasted to the single-channel performance of most commercial transducers.

New decision-making processes for the pricing of health technologies in Japan: The FY 2016/2017 pilot phase for the introduction of economic evaluations.

PubMed

Shiroiwa, Takeru; Fukuda, Takashi; Ikeda, Shunya; Takura, Tomoyuki

2017-08-01

Economic evaluation is used for decision-making processes in healthcare technologies in many developed countries. In Japan, no health economic data have been requested for drugs, medical devices, and interventions till date. However, economic evaluation is gradually gaining importance, and a trial implementation of the cost-effectiveness evaluation of drugs and medical devices has begun. Discussions on economic evaluation began in May 2012 within a newly established sub-committee of the Chuikyo, referred to as the "Special Committee on Cost Effectiveness." After four years of discussions, this committee determined that during the trial implementation, the results of the cost-effectiveness evaluation would be used for the re-pricing of drugs and medical devices at the end of fiscal year (FY) 2017. Chuikyo selected 13 products (7 drugs and 6 medical devices) as targets for this evaluation. These products will be evaluated until the end of FY 2017 based on the following process: manufacturers will submit the data of economic evaluation; the National Institute of Public Health will coordinate the review process; academic groups will perform the actual review of the submitted data, and the expert committee will appraise these data. This represents the first step to introducing cost-effectiveness analysis in the Japanese healthcare system. We believe that these efforts will contribute to the efficiency and sustainability of the Japanese healthcare system. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Development of an evaporation-based microfluidic sample concentrator

NASA Astrophysics Data System (ADS)

Sharma, Nigel R.; Lukyanov, Anatoly; Bardell, Ron L.; Seifried, Lynn; Shen, Mingchao

2008-02-01

MicroPlumbers Microsciences LLC, has developed a relatively simple concentrator device based on isothermal evaporation. The device allows for rapid concentration of dissolved or dispersed substances or microorganisms (e.g. bacteria, viruses, proteins, toxins, enzymes, antibodies, etc.) under conditions gentle enough to preserve their specific activity or viability. It is capable of removing of 0.8 ml of water per minute at 37°C, and has dimensions compatible with typical microfluidic devices. The concentrator can be used as a stand-alone device or integrated into various processes and analytical instruments, substantially increasing their sensitivity while decreasing processing time. The evaporative concentrator can find applications in many areas such as biothreat detection, environmental monitoring, forensic medicine, pathogen analysis, and agricultural industrial monitoring. In our presentation, we describe the design, fabrication, and testing of the concentrator. We discuss multiphysics simulations of the heat and mass transport in the device that we used to select the design of the concentrator and the protocol of performance testing. We present the results of experiments evaluating water removal performance.

Ergonomic evaluation of 3D plane positioning using a mouse and a haptic device.

PubMed

Paul, Laurent; Cartiaux, Olivier; Docquier, Pierre-Louis; Banse, Xavier

2009-12-01

Preoperative planning and intraoperative assistance are needed to improve accuracy in tumour surgery. To be accepted, these processes must be efficient. An experiment was conducted to compare a mouse and a haptic device, with and without force feedback, to perform plan positioning in a 3D space. Ergonomics and performance factors were investigated during the experiment. Positioning strategies were observed. The task completion time, number of 3D orientations and failure rate were analysed. A questionnaire on ergonomics was filled out by each participant. The haptic device showed a significantly lower failure rate and was quicker and more ergonomic than the mouse. The force feedback was not beneficial to the accomplishment of the task. The haptic device is intuitive, ergonomic and more efficient than the mouse for positioning a 3D plane into a 3D space. Useful observations regarding positioning strategies will improve the integration of haptic devices into medical applications. Copyright (c) 2009 John Wiley & Sons, Ltd.

Image degradation by glare in radiologic display devices

NASA Astrophysics Data System (ADS)

Badano, Aldo; Flynn, Michael J.

1997-05-01

No electronic devices are currently available that can display digital radiographs without loss of visual information compared to traditional transilluminated film. Light scattering within the glass faceplate of cathode-ray tube (CRT) devices causes excessive glare that reduces image contrast. This glare, along with ambient light reflection, has been recognized as a significant limitation for radiologic applications. Efforts to control the effect of glare and ambient light reflection in CRTs include the use of absorptive glass and thin film coatings. In the near future, flat panel displays (FPD) with thin emissive structures should provide very low glare, high performance devices. We have used an optical Monte Carlo simulation to evaluate the effect of glare on image quality for typical CRT and flat panel display devices. The trade-off between display brightness and image contrast is described. For CRT systems, achieving good glare ratio requires a reduction of brightness to 30-40 percent of the maximum potential brightness. For FPD systems, similar glare performance can be achieved while maintaining 80 percent of the maximum potential brightness.

Evaluation of Adaptive Subdivision Method on Mobile Device

NASA Astrophysics Data System (ADS)

Rahim, Mohd Shafry Mohd; Isa, Siti Aida Mohd; Rehman, Amjad; Saba, Tanzila

2013-06-01

Recently, there are significant improvements in the capabilities of mobile devices; but rendering large 3D object is still tedious because of the constraint in resources of mobile devices. To reduce storage requirement, 3D object is simplified but certain area of curvature is compromised and the surface will not be smooth. Therefore a method to smoother selected area of a curvature is implemented. One of the popular methods is adaptive subdivision method. Experiments are performed using two data with results based on processing time, rendering speed and the appearance of the object on the devices. The result shows a downfall in frame rate performance due to the increase in the number of triangles with each level of iteration while the processing time of generating the new mesh also significantly increase. Since there is a difference in screen size between the devices the surface on the iPhone appears to have more triangles and more compact than the surface displayed on the iPad. [Figure not available: see fulltext.

Accelerometer-based on-body sensor localization for health and medical monitoring applications

PubMed Central

Vahdatpour, Alireza; Amini, Navid; Xu, Wenyao; Sarrafzadeh, Majid

2011-01-01

In this paper, we present a technique to recognize the position of sensors on the human body. Automatic on-body device localization ensures correctness and accuracy of measurements in health and medical monitoring systems. In addition, it provides opportunities to improve the performance and usability of ubiquitous devices. Our technique uses accelerometers to capture motion data to estimate the location of the device on the user’s body, using mixed supervised and unsupervised time series analysis methods. We have evaluated our technique with extensive experiments on 25 subjects. On average, our technique achieves 89% accuracy in estimating the location of devices on the body. In order to study the feasibility of classification of left limbs from right limbs (e.g., left arm vs. right arm), we performed analysis, based of which no meaningful classification was observed. Personalized ultraviolet monitoring and wireless transmission power control comprise two immediate applications of our on-body device localization approach. Such applications, along with their corresponding feasibility studies, are discussed. PMID:22347840

21 CFR 26.39 - Equivalence assessment.

Code of Federal Regulations, 2010 CFR

2010-04-01

... RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS... perform any type of quality system or product evaluation covered by this subpart and with regard to any... any type of quality system or product evaluation. (b) The parties shall allow CAB's not listed for...

Evaluation of innovative devices to control traffic entering from low-volume access points within a land closure.

DOT National Transportation Integrated Search

2014-04-01

This report describes the methodology and results of analyses performed to identify and evaluate : alternative methods to control traffic entering a lane closure on a two-lane, two-way road from low-volume : access points. Researchers documented the ...

Feasibility of Crosslinked Acrylic Shape Memory Polymer for a Thrombectomy Device

PubMed Central

Muschenborn, Andrea D.; Hearon, Keith; Volk, Brent L.; Conway, Jordan W.; Maitland, Duncan J.

2014-01-01

Purpose To evaluate the feasibility of utilizing a system of SMP acrylates for a thrombectomy device by determining an optimal crosslink density that provides both adequate recovery stress for blood clot removal and sufficient strain capacity to enable catheter delivery. Methods Four thermoset acrylic copolymers containing benzylmethacrylate (BzMA) and bisphenol A ethoxylate diacrylate (Mn~512, BPA) were designed with differing thermomechanical properties. Finite element analysis (FEA) was performed to ensure that the materials were able to undergo the strains imposed by crimping, and fabricated devices were subjected to force-monitored crimping, constrained recovery, and bench-top thrombectomy. Results Devices with 25 and 35 mole% BPA exhibited the highest recovery stress and the highest brittle response as they broke upon constrained recovery. On the contrary, the 15 mole % BPA devices endured all testing and their recovery stress (5 kPa) enabled successful bench-top thrombectomy in 2/3 times, compared to 0/3 for the devices with the lowest BPA content. Conclusion While the 15 mole% BPA devices provided the best trade-off between device integrity and performance, other SMP systems that offer recovery stresses above 5 kPa without increasing brittleness to the point of causing device failure would be more suitable for this application. PMID:25414549

Micromachined structures for vertical microelectrooptical devices on InP

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

Seassal, C.; Leclercq, J.L.; Letartre, X.

1996-12-31

The authors presented a microstructuring method in order to fabricate tunable vertical resonant cavity optical devices. PL characterizations were performed on a test structure in order to evaluate the effect of the cavity thickness on the peak characteristics. Modeling of the mechanical, electrostatic, and optical behavior of the device, PL simulation were performed, and showed a good agreement with the experiments. This is a first preliminary validation of InP-based MOEMS for further realization of tunable wavelength-selective passive filters, or photodiodes and lasers by incorporating active region within the cavity. Micro-reflectivity measurements with a spatial resolution of 20 {micro}m are underwaymore » in their group, in order to measure directly the resonance shift and spectral linewidth.« less

Field evaluation of a prototype paper-based point-of-care fingerstick transaminase test.

PubMed

Pollock, Nira R; McGray, Sarah; Colby, Donn J; Noubary, Farzad; Nguyen, Huyen; Nguyen, The Anh; Khormaee, Sariah; Jain, Sidhartha; Hawkins, Kenneth; Kumar, Shailendra; Rolland, Jason P; Beattie, Patrick D; Chau, Nguyen V; Quang, Vo M; Barfield, Cori; Tietje, Kathy; Steele, Matt; Weigl, Bernhard H

2013-01-01

Monitoring for drug-induced liver injury (DILI) via serial transaminase measurements in patients on potentially hepatotoxic medications (e.g., for HIV and tuberculosis) is routine in resource-rich nations, but often unavailable in resource-limited settings. Towards enabling universal access to affordable point-of-care (POC) screening for DILI, we have performed the first field evaluation of a paper-based, microfluidic fingerstick test for rapid, semi-quantitative, visual measurement of blood alanine aminotransferase (ALT). Our objectives were to assess operational feasibility, inter-operator variability, lot variability, device failure rate, and accuracy, to inform device modification for further field testing. The paper-based ALT test was performed at POC on fingerstick samples from 600 outpatients receiving HIV treatment in Vietnam. Results, read independently by two clinic nurses, were compared with gold-standard automated (Roche Cobas) results from venipuncture samples obtained in parallel. Two device lots were used sequentially. We demonstrated high inter-operator agreement, with 96.3% (95% C.I., 94.3-97.7%) agreement in placing visual results into clinically-defined "bins" (<3x, 3-5x, and >5x upper limit of normal), >90% agreement in validity determination, and intraclass correlation coefficient of 0.89 (95% C.I., 0.87-0.91). Lot variability was observed in % invalids due to hemolysis (21.1% for Lot 1, 1.6% for Lot 2) and correlated with lots of incorporated plasma separation membranes. Invalid rates <1% were observed for all other device controls. Overall bin placement accuracy for the two readers was 84% (84.3%/83.6%). Our findings of extremely high inter-operator agreement for visual reading-obtained in a target clinical environment, as performed by local practitioners-indicate that the device operation and reading process is feasible and reproducible. Bin placement accuracy and lot-to-lot variability data identified specific targets for device optimization and material quality control. This is the first field study performed with a patterned paper-based microfluidic device and opens the door to development of similar assays for other important analytes.

Optimization of Processing and Modeling Issues for Thin Film Solar Cell Devices Including Concepts for The Development of Polycrystalline Multijunctions: Annual Report; 24 August 1998-23 August 1999

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

Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.

2000-08-25

This report describes results achieved during phase 1 of a three-phase subcontract to develop and understand thin-film solar cell technology associated to CuInSe{sub 2} and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE long-range efficiency, reliability, and manufacturing cost goals. The critical issues being addressed under this program are intended to provide the science and engineering basis for the development of viable commercial processes and to improve module performance. The generic research issues addressed are: (1) quantitative analysis of processing steps to provide information for efficient commercial-scalemore » equipment design and operation; (2) device characterization relating the device performance to materials properties and process conditions; (3) development of alloy materials with different bandgaps to allow improved device structures for stability and compatibility with module design; (4) development of improved window/heterojunction layers and contacts to improve device performance and reliability; and (5) evaluation of cell stability with respect to illumination, temperature, and ambient and with respect to device structure and module encapsulation.« less

Compact, Controlled Resistance Exercise Device

NASA Technical Reports Server (NTRS)

Paulus, David C.; DeWitt, John K.; Reich, Alton J.; Shaw, James E.; Deaconu, Stelu S.

2011-01-01

Spaceflight leads to muscle and bone atrophy. Isoinertial (free-weight) exercises provide a sufficient stimulus to elicit increases in both muscle strength and bone mineral density in Earth-based studies. While exercise equipment is in use on the International Space Station for crewmember health maintenance, current devices are too large to place in a transport vehicle or small spacecraft. Therefore, a portable computer controlled resistance exercise device is being developed that is able to simulate the inertial loading experienced when lifting a mass on Earth. This portable device weighs less than 50 lb and can simulate the resistance of lifting and lowering up to 600 lb of free-weights. The objective is to allow crewmembers to perform resistance exercise with loads capable of maintaining muscle and bone health. The device is reconfigurable and allows for the performance of typical Earth-based free-weight exercises. Forces exerted, volume of work, range of motion, time-under-tension, and speed/ acceleration of movement are recorded and can be remotely monitored to track progress and modify individual protocols based on exercise session data. A performance evaluation will be completed and data will be presented that include ground-reaction force comparisons between the device and free-weight dead-lifts over a spectrum of resistance levels. Movement biomechanics will also be presented.

Validation of Omron RS8, RS6, and RS3 home blood pressure monitoring devices, in accordance with the European Society of Hypertension International Protocol revision 2010.

PubMed

Takahashi, Hakuo; Yoshika, Masamichi; Yokoi, Toyohiko

2013-01-01

Allowing patients to measure their blood pressure at home is recognized as being of clinical value. However, it is not known how often these measurements are taken correctly. Blood pressure monitors for home use fall into two types based on the position of the cuff, ie, at the upper arm or the wrist. The latter is particularly convenient, as measurements can be taken fully clothed. This study aimed to evaluate the performance of the wrist-type blood pressure monitors Omron RS8 (HEM-6310F-E), Omron RS6 (HEM-6221-E), and Omron RS3 (HEM-6130-E). A team of three trained doctors validated the performance of these devices by comparing the measurements obtained from these devices with those taken using a standard mercury sphygmomanometer. All the devices met the validation requirements of the European Society of Hypertension International Protocol revision 2010. The difference in blood pressure readings between the tested device and the standard mercury sphygmomanometer was within 3 mmHg, which is acceptable according to the European Society of Hypertension guidelines. All the home devices tested were found to be suitable for measuring blood pressure at home because their performance fulfilled the requirement of the guidelines.

Evaluation of two glucose meters and interference corrections for screening neonatal hypoglycemia.

PubMed

Wada, Yuka; Nakamura, Tomoo; Kaneshige, Masao; Takahashi, Shigehiro; Fujinaga, Hideshi; Tsukamoto, Keiko; Ito, Yushi; Sago, Haruhiko

2015-08-01

Many neonatal intensive care and maternal units still use self-monitoring of blood glucose (SMBG) devices as a tool to aid diagnosis despite the introduction of point-of-care testing (POCT) devices, which are known to have higher accuracy. We evaluated the performance of two glucose meters, the StatStrip (Nova Biomedical), a POCT device, and the Medisafe Mini (Terumo), an SMBG device, to detect hypoglycemia in neonates. In addition, we evaluated the interference of hematocrit, acetaminophen and ascorbic acid. Whole blood samples were drawn from neonates who were at risk of hypoglycemia and analyzed with the StatStrip and Medisafe Mini. The results were further confirmed with blood gas analyzers ABL825 and BM6050. To evaluate the interference of hematocrit, acetaminophen and ascorbic acid, concentrated solutions of glucose and interfering substances were gravimetrically prepared and analyzed. Among the 222 blood samples analyzed, results from the StatStrip were more closely aligned to those of the ABL825 at all levels of glucose than the Medisafe Mini. StatStrip appears to be unaffected by hematocrit, ascorbic acid or acetaminophen. We recommend its use in neonates in hospital. Further studies are required to identify other interference effects. © 2014 Japan Pediatric Society.

A randomized multi-institutional crossover comparison of the GlideScope® Cobalt Video laryngoscope to the flexible fiberoptic bronchoscope in a Pierre Robin manikin.

PubMed

Fiadjoe, John E; Hirschfeld, Matthew; Wu, Stephan; Markley, James; Gurnaney, Harshad; Jawad, Abbas F; Stricker, Paul; Kilbaugh, Todd; Ross, Patrick; Kovatsis, Pete

2015-08-01

The GlideScope Cobalt Video laryngoscope is being used more often in children with challenging laryngoscopy. There are, however, no pediatric trials comparing it to flexible fiberoptic bronchoscopy, the current accepted gold standard. This preliminary manikin study compares the first-attempt intubation success of the GlideScope Cobalt video laryngoscope to the flexible fiberoptic bronchoscope when performed by attending pediatric anesthesiologists at two major pediatric centers. This prospective randomized, crossover study evaluated 120 attempts (60 with each study device) to intubate the AirSim Pierre Robin manikin (PRM) with fiberoptic bronchoscopy and video laryngoscopy (VL). Attending pediatric anesthesiologists from two quaternary pediatric centers were eligible to participate. Each attending anesthesiologist randomly performed a single tracheal intubation attempt with one of the study devices followed by the alternate method. The primary outcome was the first-attempt success rate of tracheal intubation. Blinding was not feasible. We hypothesized that first-attempt success would be higher with fiberoptic bronchoscopy. Thirty anesthesiologists from each center were randomized to use one of the study devices followed by the alternate method. We analyzed all participants' data. There was no overall difference in first-attempt success between VL and fiberoptic bronchoscopy (88.3% vs 85% respectively, P = 0.59). There were significant institutional differences in first-attempt success using VL (76.7% vs 100%). There was no difference in first-attempt success of tracheal intubation using VL vs fiberoptic bronchoscopy when performed by attending anesthesiologists at two large pediatric centers. However, institutional differences exist in success rates with VL across the two centers. Results from single-center device evaluations should be verified by multi-center evaluations. A significant proportion of attending anesthesiologists lack experience with advanced airway devices; targeted education may enhance intubation success and patient safety. © 2015 John Wiley & Sons Ltd.

Pointing Device Performance in Steering Tasks.

PubMed

Senanayake, Ransalu; Goonetilleke, Ravindra S

2016-06-01

Use of touch-screen-based interactions is growing rapidly. Hence, knowing the maneuvering efficacy of touch screens relative to other pointing devices is of great importance in the context of graphical user interfaces. Movement time, accuracy, and user preferences of four pointing device settings were evaluated on a computer with 14 participants aged 20.1 ± 3.13 years. It was found that, depending on the difficulty of the task, the optimal settings differ for ballistic and visual control tasks. With a touch screen, resting the arm increased movement time for steering tasks. When both performance and comfort are considered, whether to use a mouse or a touch screen for person-computer interaction depends on the steering difficulty. Hence, a input device should be chosen based on the application, and should be optimized to match the graphical user interface. © The Author(s) 2016.

Efficacy of anti-retraction devices in preventing bacterial contamination of dental unit water lines.

PubMed

Berlutti, Francesca; Testarelli, Luca; Vaia, Francesco; De Luca, Massimo; Dolci, Giovanni

2003-02-01

In this study we examine the efficacy of anti-retraction devices in preventing microbial contamination of dental unit water lines (DUWLs). The study was performed on 54 randomly selected DUs in use at private and public institutions for over six months. The selected DUs were all currently commercially available. To evaluate the efficiency of anti-retraction devices, two different methods were employed, mechanical and microbiological. The ADA/ANSI specification #47 (corresponding to a water retraction of less than 40.3 microl) was used for the evaluation of the retraction determined using the mechanical method; the presence/absence of test microorganisms in DUWLs upstream the turbine after the test was used for evaluating the microbiological assay. Both evaluation methods indicated correct amounts of retraction and prevention of DUWL contamination occurred in only two cases (3.7%). Correct retraction was noted in six other dental units (DUs), but their DUWLs became contaminated during testing. Six other produced the opposite results-improper retraction, yet no contamination. The remaining 40 DUs (74.0%) failed both evaluations. The results showed that the overwhelming majority of the anti-retraction devices did not prevent retraction when the turbine stopped running, leading to a contamination of the water lines, and to a consequent possible cross-contamination of the patients.

Evaluating the performance of microbial fuel cells powering electronic devices

NASA Astrophysics Data System (ADS)

Dewan, Alim; Donovan, Conrad; Heo, Deukhyoun; Beyenal, Haluk

A microbial fuel cell (MFC) is capable of powering an electronic device if we store the energy in an external storage device, such as a capacitor, and dispense that energy intermittently in bursts of high-power when needed. Therefore its performance needs to be evaluated using an energy-storing device such as a capacitor which can be charged and discharged rather than other evaluation techniques, such as continuous energy dissipation through a resistor. In this study, we develop a method of testing microbial fuel cell performance based on storing energy in a capacitor. When a capacitor is connected to a MFC it acts like a variable resistor and stores energy from the MFC at a variable rate. In practice the application of this method to testing microbial fuel cells is very challenging and time consuming; therefore we have custom-designed a microbial fuel cell tester (MFCT). The MFCT evaluates the performance of a MFC as a power source. It uses a capacitor as an energy storing device and waits until a desired amount of energy is stored then discharges the capacitor. The entire process is controlled using an analog-to-digital converter (ADC) board controlled by a custom-written computer program. The utility of our method and the MFCT is demonstrated using a laboratory microbial fuel cell (LMFC) and a sediment microbial fuel cell (SMFC). We determine (1) how frequently a MFC can charge a capacitor, (2) which electrode is current-limiting, (3) what capacitor value will allow the maximum harvested energy from a MFC, which is called the "optimum charging capacitor value," and (4) what capacitor charging potential will harvest the maximum energy from a MFC, which is called the "optimum charging potential." Using a LMFC we find that (1) the time needed to charge a 3-F capacitor from 0 to 500 mV is 108 min, (2) the optimum charging capacitor value is 3 F, and (3) the optimum charging potential is 300 mV. Using a SMFC we find that (1) the time needed to charge a 3-F capacitor from 0 to 500 mV is 5 min, (2) the optimum charging capacitor value is 3 F, and (3) the optimum charging potential is 500 mV. Our results demonstrate that the developed method and the MFCT can be used to evaluate and optimize energy harvesting when a MFC is used with a capacitor to power wireless sensors monitoring the environment.

Performance evaluation of a high power DC-DC boost converter for PV applications using SiC power devices

NASA Astrophysics Data System (ADS)

Almasoudi, Fahad M.; Alatawi, Khaled S.; Matin, Mohammad

2016-09-01

The development of Wide band gap (WBG) power devices has been attracted by many commercial companies to be available in the market because of their enormous advantages over the traditional Si power devices. An example of WBG material is SiC, which offers a number of advantages over Si material. For example, SiC has the ability of blocking higher voltages, reducing switching and conduction losses and supports high switching frequency. Consequently, SiC power devices have become the affordable choice for high frequency and power application. The goal of this paper is to study the performance of 4.5 kW, 200 kHz, 600V DC-DC boost converter operating in continuous conduction mode (CCM) for PV applications. The switching behavior and turn on and turn off losses of different switching power devices such as SiC MOSFET, SiC normally ON JFET and Si MOSFET are investigated and analyzed. Moreover, a detailed comparison is provided to show the overall efficiency of the DC-DC boost converter with different switching power devices. It is found that the efficiency of SiC power switching devices are higher than the efficiency of Si-based switching devices due to low switching and conduction losses when operating at high frequencies. According to the result, the performance of SiC switching power devices dominate the conventional Si power devices in terms of low losses, high efficiency and high power density. Accordingly, SiC power switching devices are more appropriate for PV applications where a converter of smaller size with high efficiency, and cost effective is required.

Temperature and time variations during osteotomies performed with different piezosurgical devices: an in vitro study.

PubMed

Delgado-Ruiz, R A; Sacks, D; Palermo, A; Calvo-Guirado, J L; Perez-Albacete, C; Romanos, G E

2016-09-01

The aim of this experimental in vitro study was to evaluate the effects of the piezoelectric device in temperature and time variations in standardized osteotomies performed with similar tip inserts in bovine bone blocks. Two different piezosurgical devices were used the OE-F15(®) (Osada Inc., Los Angeles, California, USA) and the Surgybone(®) (Silfradent Inc., Sofia, Forli Cesena, Italy). Serrated inserts with similar geometry were coupled with each device (ST94 insert/test A and P0700 insert/test B). Osteotomies 10 mm long and 3 mm deep were performed in bone blocks resembling type II (dense) and type IV (soft) bone densities with and without irrigation. Thermal changes and time variations were recorded. The effects of bone density, irrigation, and device on temperature changes and time necessary to accomplish the osteotomies were analyzed. Thermal analysis showed significant higher temperatures during piezosurgery osteotomies in hard bone without irrigation (P < 0.05). The type of piezosurgical device did not influence thermal variations (P > 0.05). Time analysis showed that the mean time values necessary to perform osteotomies were shorter in soft bone than in dense bone (P < 0.05). Within the limitations of this in vitro study, it may be concluded that the temperature increases more in piezosurgery osteotomies in dense bone without irrigation; the time to perform the osteotomy with piezosurgery is shorter in soft bone compared to hard bone; and the piezosurgical device have a minimal influence in the temperature and time variations when a similar tip design is used during piezosurgery osteotomies. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evaluation of autoCPAP devices in home treatment of sleep apnea/hypopnea syndrome.

PubMed

Meurice, J C; Cornette, A; Philip-Joet, F; Pepin, J L; Escourrou, P; Ingrand, P; Veale, D

2007-11-01

Quality of life (QOL) and sleepiness for patients with sleep apnea/hypopnea syndrome (SAHS) might improve with continuous positive airway pressure devices working in auto-adjust mode (autoCPAP) by allowing pressure modulations following patient needs. Clinical comparisons between devices driven by different algorithms are needed. We compared the clinical effectiveness of fixed pressure CPAP and four different autoCPAP devices by assessing compliance and QOL (36-item short-form health survey [SF-36]). SAHS patients were randomly allocated to five groups. Polysomnography (PSG) was performed to titrate the effective pressure in the constant CPAP group and evaluate residual apnea/hypopnea index (AHI) under autoCPAP. Follow-up consisted of clinical visits at three and six months by homecare technicians who assessed compliance, symptom scores and SF-36 scores. A laboratory-based PSG using the same CPAP/autoCPAP device as at home was performed at six months. Eighty-three patients (mean age 56+/-10 yrs) with mean body mass index (BMI) 30.8+/-5.3 kg/m(2) and severe SAHS (mean AHI: 52.3+/-17.8/h) were included. There were no differences in clinical symptoms or QOL scores, and similar clinical and PSG improvements were seen in all groups. CPAP use was >5 h per night, without any significant difference between groups. AutoCPAP is equally as effective as fixed CPAP for long-term home treatment in severe SAHS patients.

Evaluation of input devices for teleoperation of concentric tube continuum robots for surgical tasks

NASA Astrophysics Data System (ADS)

Fellmann, Carolin; Kashi, Daryoush; Burgner-Kahrs, Jessica

2015-03-01

For those minimally invasive surgery where conventional surgical instruments cannot reach the surgical site due to their straight structure and rigidity, concentric tube continuum robots are a promising technology because of their small size (comparable to a needle) and maneuverability. These flexible, compliant manipulators can easily access hard to reach anatomical structures, e.g. by turning around corners. By teleoperating the robot the surgeon stays in direct control at any time. In this paper, three off-the-shelf input devices are considered for teleoperation of a concentric tube continuum robot: a 3D mouse, a gamepad, and a 3 degrees of freedom haptic input device. Three tasks which mimic relevant surgical maneuvers are performed by 12 subjects using each input device: reaching specific locations, picking and placing objects from one location to another, and approaching the surgical site through a restricted pathway. We present quantitative results (task completion time, accuracy, etc.), a statistical analysis, and empirical results (questionnaires). Overall, the performance of subjects using the 3D mouse was superior to the performance using the other input devices. The subjective ranking of the 3D mouse by the subjects confirms this result.

Performance of an SOI Boot-Strapped Full-Bridge MOSFET Driver, Type CHT-FBDR, under Extreme Temperatures

NASA Technical Reports Server (NTRS)

Patterson, Richard; Hammoud, Ahmad

2009-01-01

Electronic systems designed for use in deep space and planetary exploration missions are expected to encounter extreme temperatures and wide thermal swings. Silicon-based devices are limited in their wide-temperature capability and usually require extra measures, such as cooling or heating mechanisms, to provide adequate ambient temperature for proper operation. Silicon-On-Insulator (SOI) technology, on the other hand, lately has been gaining wide spread use in applications where high temperatures are encountered. Due to their inherent design, SOI-based integrated circuit chips are able to operate at temperatures higher than those of the silicon devices by virtue of reducing leakage currents, eliminating parasitic junctions, and limiting internal heating. In addition, SOI devices provide faster switching, consume less power, and offer improved radiation-tolerance. Very little data, however, exist on the performance of such devices and circuits under cryogenic temperatures. In this work, the performance of an SOI bootstrapped, full-bridge driver integrated circuit was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to establish a baseline on the functionality and to determine suitability of this device for use in space exploration missions under extreme temperature conditions.

Haptic device development based on electro static force of cellulose electro active paper

NASA Astrophysics Data System (ADS)

Yun, Gyu-young; Kim, Sang-Youn; Jang, Sang-Dong; Kim, Dong-Gu; Kim, Jaehwan

2011-04-01

Haptic is one of well-considered device which is suitable for demanding virtual reality applications such as medical equipment, mobile devices, the online marketing and so on. Nowadays, many of concepts for haptic devices have been suggested to meet the demand of industries. Cellulose has received much attention as an emerging smart material, named as electro-active paper (EAPap). The EAPap is attractive for mobile haptic devices due to its unique characteristics in terms of low actuation power, suitability for thin devices and transparency. In this paper, we suggest a new concept of haptic actuator with the use of cellulose EAPap. Its performance is evaluated depending on various actuation conditions. As a result, cellulose electrostatic force actuator shows a large output displacement and fast response, which is suitable for mobile haptic devices.

A difficult decision: what should we do when malignant tumours are diagnosed in patients supported by left ventricular assist devices?

PubMed

Smail, Hassiba; Pfister, Christian; Baste, Jean-Marc; Nafeh-Bizet, Catherine; Gay, Arnaud; Barbay, Virginie; Bessou, Jean-Paul; Peillon, Christophe; Litzler, Pierre-Yves

2015-09-01

Left ventricular assist devices (LVADs) are used as a bridge to heart transplantation. During the preimplantation or pretransplantation screening, malignant tumours can be discovered. Owing to the lack of guidelines, the management is difficult. We describe our perioperative approach and the patients' outcomes. Between 2006 and 2014, 55 patients underwent implantation of HeartMate II LVAD. Five were diagnosed with malignant tumours: 2 renal, 2 lung and 1 breast tumours. The renal tumours were diagnosed during the preimplantation screening. An LVAD was implanted in both followed by partial nephrectomies 8 and 9 months later. The lung cancers were diagnosed after device implantation, a left pulmonary segmentectomy and a right upper sleeve lobectomy were performed. The breast cancer was diagnosed few months after support and a tumourectomy with lymphadenectomy was performed. Tumour resection was performed successfully in all patients. Prior to surgery haemostasis, device and heart function were evaluated. During surgery, haemodynamics and anticoagulation were monitored. Reoperations were necessary to evacuate haemothorax after lobectomy and an abdominal haematoma post-nephrectomy. After discussion with oncologists, 3 patients were relisted for heart transplantation. Two were successfully transplanted 2 and 3 years after partial nephrectomy with an actual survival of 56 and 59 months after the cancer diagnosis. The follow-up revealed no cancer recurrences. Malignant tumours during support with LVAD can be successfully resected. A multidisciplinary evaluation in these high-risk patients is mandatory. After careful evaluation, regaining the patient's heart transplant candidacy is possible. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Direct current stimulation of titanium interbody fusion devices in primates.

PubMed

Cook, Stephen D; Patron, Laura P; Christakis, Petros M; Bailey, Kirk J; Banta, Charles; Glazer, Paul A

2004-01-01

The fusion rate for anterior lumbar interbody fusion (ALIF) varies widely with the use of different interbody devices and bone graft options. Adjunctive techniques such as electrical stimulation may improve the rate of bony fusion. To determine if direct current (DC) electrical stimulation of a metallic interbody fusion device enhanced the incidence or extent of anterior bony fusion. ALIF was performed using titanium alloy interbody fusion devices with and without adjunctive DC electrical stimulation in nonhuman primates. ALIF was performed through an anterolateral approach in 35 macaques with autogenous bone graft and either a titanium alloy (Ti-6Al-4V) fusion device or femoral allograft ring. The fusion devices of 19 animals received high (current density 19.6 microA/cm2) or low (current density 5.4 microA/cm2) DC electrical stimulation using an implanted generator for a 12- or 26-week evaluation period. Fusion sites were studied using serial radiographs, computed tomography imaging, nondestructive mechanical testing and qualitative and semiquantitative histology. Fusion was achieved with the titanium fusion device and autogenous bone graft. At 12 weeks, the graft was consolidating and early to moderate bridging callus was observed in and around the device. By 26 weeks, the anterior callus formation was more advanced with increased evidence of bridging trabeculations and early bone remodeling. The callus formation was not as advanced or abundant for the allograft ring group. Histology revealed the spinal fusion device had an 86% incidence of bony fusion at 26 weeks compared with a 50% fusion rate for the allograft rings. DC electrical stimulation of the fusion device had a positive effect on anterior interbody fusion by increasing both the presence and extent of bony fusion in a current density-dependent manner. Adjunctive DC electrical stimulation of the fusion device improved the rate and extent of bony fusion compared with a nonstimulated device. The fusion device was equivalent to or better than the femoral allograft ring in all evaluations. The use of adjunctive direct current electrical stimulation may provide a means of improving anterior interbody fusion.

A C-Te-based binary OTS device exhibiting excellent performance and high thermal stability for selector application.

PubMed

Chekol, Solomon Amsalu; Yoo, Jongmyung; Park, Jaehyuk; Song, Jeonghwan; Sung, Changhyuck; Hwang, Hyunsang

2018-08-24

In this letter, we demonstrate a new binary ovonic threshold switching (OTS) selector device scalable down to ø30 nm based on C-Te. Our proposed selector device exhibits outstanding performance such as a high switching ratio (I on /I off  > 10 5 ), an extremely low off-current (∼1 nA), an extremely fast operating speed of <10 ns (transition time of <2 ns and delay time of <8 ns), high endurance (10 9 ), and high thermal stability (>450 °C). The observed high thermal stability is caused by the relatively small atomic size of C, compared to Te, which can effectively suppress the segregation and crystallization of Te in the OTS film. Furthermore, to confirm the functionality of the selector in a crossbar array, we evaluated a 1S-1R device by integrating our OTS device with a ReRAM (resistive random access memory) device. The 1S-1R integrated device exhibits a successful suppression of leakage current at the half-selected cell and shows an excellent read-out margin (>2 12 word lines) in a fast read operation.

LEO Flight Testing of GaAs on Si Solar Cells Aboard MISSES

NASA Technical Reports Server (NTRS)

Wilt, David M.; Clark, Eric B.; Ringel, Steven A.; Andre, Carrie L.; Smith, Mark A.; Scheiman, David A.; Jenkins, Phillip P.; Maurer, William F.; Fitzgerald, Eugene A.; Walters, R. J.

2004-01-01

Previous research efforts have demonstrated small area (0.04 cm) GaAs on Si (GaAs/Si) solar cells with AM0 efficiencies in excess of 17%. These results were achieved on Si substrates coated with a step graded buffer of Si(x),Ge(1-x) alloys graded to 100% Ge. Recently, a 100-fold increase in device area was accomplished for these devices in preparation for on-orbit testing of this technology aboard Materials International Space Station Experiment number 5 (MISSE5). The GaAs/Si MISSE5 experiment contains five (5) GaAs/Si test devices with areas of lcm(exp 2) and 4cm(exp 4) as well as two (2) GaAs on GaAs control devices. Electrical performance data, measured on-orbit for three (3) of the test devices and one (1) of the control devices, will be telemetered to ground stations daily. After approximately one year on orbit, the MISSE5 payload will be returned to Earth for post flight evaluation. This paper will discuss the development of the GaAs/Si devices for the MISSE5 flight experiment and will present recent ground and on-orbit performance data.

Vehicle brake testing system

DOEpatents

Stevens, Samuel S [Harriman, TN; Hodgson, Jeffrey W [Lenoir City, TN

2002-11-19

This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

Evaluation of effectiveness of various devices for attenuation of trailing vortices based on model tests in a large towing basin

NASA Technical Reports Server (NTRS)

Kirkman, K. L.; Brown, C. E.; Goodman, A.

1973-01-01

The effectiveness of various candidate aircraft-wing devices for attenuation of trailing vortices generated by large aircraft is evaluated on basis of results of experiments conducted with a 0.03-scale model of a Boeing 747 transport aircraft using a technique developed at the HYDRONAUTICS Ship Model Basin. Emphasis is on the effects produced by these devices in the far-field (up to 8 kilometers downstream of full-scale generating aircraft) where the unaltered vortex-wakes could still be hazardous to small following aircraft. The evaluation is based primarily on quantitative measurements of the respective vortex velocity distributions made by means of hot-film probe traverses in a transverse plane at selected stations downstream. The effects of these altered wakes on rolling moment induced on a small following aircraft are also studied using a modified lifting-surface theory with a synthesized Gates Learjet as a typical example. Lift and drag measurements concurrently obtained in the model tests are used to appraise the effects of each device investigated on the performance characteristics of the generating aircraft.

In-line task 57: Component evaluation. [of circuit breakers, panel switches, etc. for space shuttle

NASA Technical Reports Server (NTRS)

Boykin, J. C.

1974-01-01

Design analysis tests were performed on selected power switching components to determine the possible applicability of off-the-shelf hardware to space shuttles. Various characteristics were also evaluated in those devices to determine the most desirable properties for the space shuttle.

The evaluation of a new apheresis device for automated red blood cell exchange procedures in patients with sickle cell disease.

PubMed

Quirolo, Keith; Bertolone, Salvatore; Hassell, Kathryn; Howard, Thomas; King, Karen E; Rhodes, Diane K; Bill, Jerry

2015-04-01

The Spectra Optia apheresis system (SO), a blood component separator, can be used to perform red blood cell exchange (RBCX) procedures for the transfusion management of sickle cell disease (SCD) in adults and children. This study was designed to evaluate the performance of the SO RBCX protocols (exchange and depletion/exchange) in patients with SCD. Patients with SCD and a need for an RBCX procedure as part of a chronic program or as a single procedure were enrolled in this multicenter, single-arm, open-label study. The primary goal of the study was to confirm that the predicted percentage of the patient's original RBCs remaining at the end of the procedure (FCRp) reflects the actual cell fraction remaining, as measured by %HbS (FCRa). Secondary endpoints included ability of the SO to achieve the desired final hematocrit (Hct) and device-related serious adverse events (SAEs). Seventy-two patients 12 years of age or older were enrolled in the study; 60 were evaluable. The ratio of FCRa to FCRp after the RBCX procedure was 0.90, well within the prespecified range of 0.75 to 1.25. The SO was able to achieve the desired final Hct in the evaluable population. The safety profile was favorable, and no patients had an SAE or unexpected adverse device effect or withdrew from the procedure or treatment due to an adverse event. The SO performed effectively and safely for both the RBCX procedure and the RBCX depletion/exchange procedure. © 2014 AABB.

78 FR 24817 - Visual-Manual NHTSA Driver Distraction Guidelines for In-Vehicle Electronic Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-26

...The National Highway Traffic Safety Administration (NHTSA) is concerned about the effects of distraction on motor vehicle safety due to drivers' use of electronic devices. Consequently, NHTSA is issuing nonbinding, voluntary Driver Distraction Guidelines (NHTSA Guidelines) to promote safety by discouraging the introduction of excessively distracting devices in vehicles. This notice announces the issuance of the final version of the first phase of the NHTSA Guidelines. This first phase applies to original equipment (OE) in-vehicle electronic devices used by the driver to perform secondary tasks (communications, entertainment, information gathering, navigation tasks, etc. are considered secondary tasks) through visual-manual means (i.e., the driver looks at a device, manipulates a device-related control with his or her hand, and/or watches for visual feedback). The NHTSA Guidelines list certain secondary tasks believed by the agency to interfere inherently with a driver's ability to safely control the vehicle. The NHTSA Guidelines recommend that in-vehicle devices be designed so that they cannot be used by the driver to perform these inherently distracting secondary tasks while driving. For all other visual-manual secondary tasks, the NHTSA Guidelines specify a test method for measuring eye glance behavior during those tasks. Eye glance metrics are compared to acceptance criteria to evaluate whether a task interferes too much with driver attention, rendering it unsuitable for a driver to perform while driving. If a task does not meet the acceptance criteria, the NHTSA Guidelines recommend that the task be made inaccessible for performance by the driver while driving. In addition, the NHTSA Guidelines contain several recommendations to limit and reduce the potential for distraction associated with the use of OE in-vehicle electronic devices.

Determining the risks of clinically indicated nonthoracic magnetic resonance imaging at 1.5 T for patients with pacemakers and implantable cardioverter-defibrillators: rationale and design of the MagnaSafe Registry.

PubMed

Russo, Robert J

2013-03-01

Until recently, the presence of a permanent pacemaker or an implantable cardioverter-defibrillator has been a relative contraindication for the performance of magnetic resonance imaging (MRI). A number of small studies have shown that MRI can be performed with minimal risk when patients are properly monitored and device programming is modified appropriately for the procedure. However, the risk of performing MRI for patients with implanted cardiac devices has not been sufficiently evaluated to advocate routine clinical use. The aim of the present protocol is to prospectively determine the rate of adverse clinical events and device parameter changes in patients with implanted non-MRI-conditional cardiac devices undergoing clinically indicated nonthoracic MRI at 1.5 T. The MagnaSafe Registry is a multicenter, prospective cohort study of up to 1500 MRI examinations in patients with pacemakers or implantable cardioverter-defibrillators implanted after 2001 who undergo clinically indicated nonthoracic MRI following a specific protocol to ensure that preventable potential adverse events are mitigated. Adverse events and changes in device parameter measurements that may be associated with the imaging procedure will be documented. Through August 2012, 701 MRI studies have been performed, representing 47% of the total target enrollment. The results of this registry will provide additional documentation of the risk of MRI and will further validate a clinical protocol for screening and the performance of clinically indicated MRI for patients with implanted cardiac devices. Copyright © 2013 Mosby, Inc. All rights reserved.

Numerical study of the vertical shading devices effect on the thermal performance of promotional apartments in hot dry climate of Algeria

NASA Astrophysics Data System (ADS)

Berkouk, Djihed; Bouzir, Tallal Abdel Karim; Mazouz, Said

2018-05-01

The bioclimatic architecture considers the local climatic conditions in order to reconcile maximally the comfort condition of the occupants. Through the several simulations effectuated by the TRNSYS software, this paper shows that the new architecture produced in the south of Algeria following the northern cities tendency is not fully adapted to the hot dry climate of the southern regions, such as the city of Biskra. In these regions, the passive techniques design influence strongly on the thermal architectural space performance. In this regard, diverse of the vertical shading devices size were proposed to evaluate the impact of this passive technique on the thermal performance of the promotional apartments situated in the city of Biskra. The comparative analysis between the simulation results says that the effectiveness of the vertical shading devices on the thermal performance spaces is reducing the indoor air temperature during the summer period. In addition, this analysis shows that promotional apartments are unsuitable for the desert climate.

Operational Test and Evaluation Handbook for Aircrew Training Devices. Volume II. Operational Effectiveness Evaluation

DTIC Science & Technology

1982-02-01

should also convey an understanding of the differ- ences in learning behavior between initial learning activity and later skill maintenance and...refinement might then be, ATTACK MANEUVERS * Pop-up attack # Loft/ LADO type attack * Level/laydown attack Figure 5-4 showe diagrammatically the...sensitive to differ- ences in performance. Severai criteria should be used to guide the selection/development of performance measures, i.e., measure validity

Benthic Flux Sampling Device, Prototype Design, Development, and Evaluation

DTIC Science & Technology

1993-08-01

collaboration with Clare Reimers and Matt Christianson at Scripps Institution of Oceanography. Trace metal chemistry was performed by John Andrews and...realistic levels for coastal and inshore sediments using a sample period of 2-4 days. The resulting flux rates will be useful in evaluating the risks...suffi= for detecting release rates at significant levels . Operation Depth. A depth capability of 50 m is sufficient to perform studies in most U.S. bays

Longitudinal studies on the microcirculation around the TheraCyte immunoisolation device, using the laser Doppler technique.

PubMed

Rafael, E; Gazelius, B; Wu, G S; Tibell, A

2000-01-01

Encapsulation of cellular grafts in an immunoisolation membrane device may make it possible to perform transplantation without having to give immunosuppressive drugs. A common problem is the development of an avascular fibrotic zone around the implants, leading to impaired graft survival. The TheraCyte macroencapsulation device has therefore been designed to facilitate neovascularization of the device's surface. In this study, we evaluated the microcirculation around empty TheraCyte devices implanted SC in rats at various times after implantation, using a laser Doppler probe introduced via the device port. Studies were performed on day 1 or at 1, 2, and 4 weeks or at 2, 3, and 12 months after implantation. The mean flow was 158+/-42, 148+/-50, 133+/-28, 72+/-17, 138+/-41, 165+/-43, and 160+/-29 perfusion units (PU), respectively. Thus, the microcirculation around the device was significantly reduced at 4 weeks after implantation (p < 0.01) while, from 2 months onwards the circulation had improved and did not differ significantly from that on day 1. The present study shows time-related changes in the microcirculatory flow around TheraCyte macroencapsulation devices that agree with our previous microdialysis studies on in vivo exchange of insulin and glucose between the device and the circulation. Laser Doppler flowmetry seems to provide a reliable technique for screening blood perfusion around macroencapsulation devices.

Psychophysical evaluation of the image quality of a dynamic flat-panel digital x-ray image detector using the threshold contrast detail detectability (TCDD) technique

NASA Astrophysics Data System (ADS)

Davies, Andrew G.; Cowen, Arnold R.; Bruijns, Tom J. C.

1999-05-01

We are currently in an era of active development of the digital X-ray imaging detectors that will serve the radiological communities in the new millennium. The rigorous comparative physical evaluations of such devices are therefore becoming increasingly important from both the technical and clinical perspectives. The authors have been actively involved in the evaluation of a clinical demonstration version of a flat-panel dynamic digital X-ray image detector (or FDXD). Results of objective physical evaluation of this device have been presented elsewhere at this conference. The imaging performance of FDXD under radiographic exposure conditions have been previously reported, and in this paper a psychophysical evaluation of the FDXD detector operating under continuous fluoroscopic conditions is presented. The evaluation technique employed was the threshold contrast detail detectability (TCDD) technique, which enables image quality to be measured on devices operating in the clinical environment. This approach addresses image quality in the context of both the image acquisition and display processes, and uses human observers to measure performance. The Leeds test objects TO[10] and TO[10+] were used to obtain comparative measurements of performance on the FDXD and two digital spot fluorography (DSF) systems, one utilizing a Plumbicon camera and the other a state of the art CCD camera. Measurements were taken at a range of detector entrance exposure rates, namely 6, 12, 25 and 50 (mu) R/s. In order to facilitate comparisons between the systems, all fluoroscopic image processing such as noise reduction algorithms, were disabled during the experiments. At the highest dose rate FDXD significantly outperformed the DSF comparison systems in the TCDD comparisons. At 25 and 12 (mu) R/s all three-systems performed in an equivalent manner and at the lowest exposure rate FDXD was inferior to the two DSF systems. At standard fluoroscopic exposures, FDXD performed in an equivalent manner to the DSF systems for the TCDD comparisons. This would suggest that FDXD would therefore perform adequately in a clinical fluoroscopic environment and our initial clinical experiences support this. Noise reduction processing of the fluoroscopic data acquired on FDXD was also found to further improve TCDD performance for FDXD. FDXD therefore combines acceptable fluoroscopic performance with excellent radiographic (snap shot) imaging fidelity, allowing the possibility of a universal x-ray detector to be developed, based on FDXD's technology. It is also envisaged that fluoroscopic performance will be improved by the development of digital image enhancement techniques specifically tailored to the characteristics of the FDXD detector.

Performance evaluation of radiation sensors with internal signal amplification based on the BJT effect

NASA Astrophysics Data System (ADS)

Bosisio, Luciano; Batignani, Giovanni; Bettarini, Stefano; Boscardin, Maurizio; Dalla Betta, Gian-Franco; Giacomini, Gabriele; Piemonte, Claudio; Verzellesi, Giovanni; Zorzi, Nicola

2006-11-01

Prototypes of ionizing radiation detectors with internal signal amplification based on the bipolar transistor effect have been fabricated at ITC-irst (Trento, Italy). Results from the electrical characterization and preliminary functional tests of the devices have been previously reported. Here, we present a more detailed investigation of the performance of this type of detector, with particular attention to their noise and rate limits. Measurements of the signal waveform and of the gain versus frequency dependence are performed by illuminating the devices with, respectively, pulsed or sinusoidally modulated IR light. Pulse height spectra of X-rays from an Am241 source have been taken with very simple front-end electronics (an LF351 operational amplifier) or by directly reading with an oscilloscope the voltage drop across a load resistor connected to the emitter. An equivalent noise charge (referred to input) of 380 electrons r.m.s. has been obtained with the first setup for a small device, with an active area of 0.5×0.5 mm2 and a depleted thickness of 0.6 mm. The corresponding power dissipation in the BJT was 17 μW. The performance limitations of the devices are discussed.

40 CFR 63.1312 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Surge control vessel (§ 63.161) Temperature monitoring device (§ 63.111) Test method (§ 63.2) Treatment... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1312 Definitions. (a) The... (§ 63.111) Owner or operator (§ 63.2) Performance evaluation (§ 63.2) Performance test (§ 63.2...

Blast Mitigation Sea Analysis - Evaluation of Lumbar Compression Data Trends in 5th Percentile Female Anthropomorphic Test Device Performance Compared to 50th Percentile Male Anthropomorphic Test Device in Drop Tower Testing

DTIC Science & Technology

2016-08-21

less pronounced for pelvis velocity • Seat velocity and dynamic displacement not recorded for this test series – Would provide key information for...effectiveness of seat – Displacement /time history data should be recorded for all future test series UNCLASSIFIED UNCLASSIFIED Conclusions/Future...interfacing with seat manufacturers to broaden occupant protection range – Record dynamic stroke on all drop tower tests to evaluate correlation between displacement rate and lumbar compression UNCLASSIFIED UNCLASSIFIED 17

Moving Large Data Sets Over High-Performance Long Distance Networks

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

Hodson, Stephen W; Poole, Stephen W; Ruwart, Thomas

2011-04-01

In this project we look at the performance characteristics of three tools used to move large data sets over dedicated long distance networking infrastructure. Although performance studies of wide area networks have been a frequent topic of interest, performance analyses have tended to focus on network latency characteristics and peak throughput using network traffic generators. In this study we instead perform an end-to-end long distance networking analysis that includes reading large data sets from a source file system and committing large data sets to a destination file system. An evaluation of end-to-end data movement is also an evaluation of themore » system configurations employed and the tools used to move the data. For this paper, we have built several storage platforms and connected them with a high performance long distance network configuration. We use these systems to analyze the capabilities of three data movement tools: BBcp, GridFTP, and XDD. Our studies demonstrate that existing data movement tools do not provide efficient performance levels or exercise the storage devices in their highest performance modes. We describe the device information required to achieve high levels of I/O performance and discuss how this data is applicable in use cases beyond data movement performance.« less

Effects of Maintenance on Quality of Performance of Cryotherapy Devices for Treatment of Precancerous Cervical Lesions.

PubMed

Maza, Mauricio; Figueroa, Ruben; Laskow, Bari; Juárez, Alexa; Alfaro, Karla; Alonzo, Todd A; Felix, Juan C; Gage, Julia C; Cremer, Miriam

2018-01-01

The aim of the study was to evaluate the impact of maintenance on performance of cryosurgical equipment used in El Salvador primary health clinics. Nine gynecological cryotherapy devices used in El Salvador were bench tested against a new machine of the same make and model. The devices were run for five successive double-freeze cycles. The El Salvador machines then received maintenance by a specialized engineer and another double-freeze cycle was performed. Temperature at the device probe tip was recorded throughout each cycle and ballistic gelatin was used as the tissue analogue to measure freeze ball dimensions achieved by the devices. Outcome measures were mean lowest-sustained temperatures and freeze ball mean weight, depth, and diameter. Paired and unpaired t tests were used to compare results premaintenance versus postmaintenance and postmaintenance versus the reference, respectively. Premaintenance versus postmaintenance freeze ball dimensions were significantly different (mean differences in weight = 2.31 g, p = .01; depth = 2.29 mm, p = .03; diameter = 3.51 mm, p = .02). However, postmaintenance dimensions were not significantly different than those of the reference (weight = 7.44 g vs. 8.39 g, p = .07; depth = 10.71 vs. 11.24 mm, p = .1; diameter = 31.38 mm vs. 32.05 mm, p = .3). Postmaintenance, minimum, and lowest-sustained temperatures were within the recommended clinical range. Specialized maintenance was necessary for heavily used cryotherapy devices to perform adequately, highlighting the challenges of gas-based cryotherapy in low- and middle-income countries.

Usability Study of a Wireless Monitoring System among Alzheimer's Disease Elderly Population

PubMed Central

Avvenuti, Marco

2014-01-01

Healthcare technologies are slowly entering into our daily lives, replacing old devices and techniques with newer intelligent ones. Although they are meant to help people, the reaction and willingness to use such new devices by the people can be unexpected, especially among the elderly. We conducted a usability study of a fall monitoring system in a long-term nursing home. The subjects were the elderly with advanced Alzheimer's disease. The study presented here highlights some of the challenges faced in the use of wearable devices and the lessons learned. The results gave us useful insights, leading to ergonomics and aesthetics modifications to our wearable systems that significantly improved their usability and acceptance. New evaluating metrics were designed for the performance evaluation of usability and acceptability. PMID:24963289

Transmissive liquid-crystal device for correcting primary coma aberration and astigmatism in biospecimen in two-photon excitation laser scanning microscopy

NASA Astrophysics Data System (ADS)

Tanabe, Ayano; Hibi, Terumasa; Ipponjima, Sari; Matsumoto, Kenji; Yokoyama, Masafumi; Kurihara, Makoto; Hashimoto, Nobuyuki; Nemoto, Tomomi

2016-12-01

All aberrations produced inside a biospecimen can degrade the quality of a three-dimensional image in two-photon excitation laser scanning microscopy. Previously, we developed a transmissive liquid-crystal device to correct spherical aberrations that improved the image quality of a fixed-mouse-brain slice treated with an optical clearing reagent. In this study, we developed a transmissive device that corrects primary coma aberration and astigmatism. The motivation for this study is that asymmetric aberration can be induced by the shape of a biospecimen and/or by a complicated refractive-index distribution in a sample; this can considerably degrade optical performance even near the sample surface. The device's performance was evaluated by observing fluorescence beads. The device was inserted between the objective lens and microscope revolver and succeeded in improving the spatial resolution and fluorescence signal of a bead image that was originally degraded by asymmetric aberration. Finally, we implemented the device for observing a fixed whole mouse brain with a sloping surface shape and complicated internal refractive-index distribution. The correction with the device improved the spatial resolution and increased the fluorescence signal by ˜2.4×. The device can provide a simple approach to acquiring higher-quality images of biospecimens.

Development and evaluation of needle trap device geometry and packing methods for automated and manual analysis.

PubMed

Warren, Jamie M; Pawliszyn, Janusz

2011-12-16

For air/headspace analysis, needle trap devices (NTDs) are applicable for sampling a wide range of volatiles such as benzene, alkanes, and semi-volatile particulate bound compounds such as pyrene. This paper describes a new NTD that is simpler to produce and improves performance relative to previous NTD designs. A NTD utilizing a side-hole needle used a modified tip, which removed the need to use epoxy glue to hold sorbent particles inside the NTD. This design also improved the seal between the NTD and narrow neck liner of the GC injector; therefore, improving the desorption efficiency. A new packing method has been developed and evaluated using solvent to pack the device, and is compared to NTDs prepared using the previous vacuum aspiration method. The slurry packing method reduced preparation time and improved reproducibility between NTDs. To evaluate the NTDs, automated headspace extraction was completed using benzene, toluene, ethylbenzene, p-xylene (BTEX), anthracene, and pyrene (PAH). NTD geometries evaluated include: blunt tip with side-hole needle, tapered tip with side-hole needle, slider tip with side-hole, dome tapered tip with side-hole and blunt with no side-hole needle (expanded desorptive flow). Results demonstrate that the tapered and slider tip NTDs performed with improved desorption efficiency. Copyright © 2011 Elsevier B.V. All rights reserved.

Registry Assessment of Peripheral Interventional Devices (RAPID)　- Registry Assessment of Peripheral Interventional Devices Core Data Elements.

PubMed

Jones, W Schuyler; Krucoff, Mitchell W; Morales, Pablo; Wilgus, Rebecca W; Heath, Anne H; Williams, Mary F; Tcheng, James E; Marinac-Dabic, J Danica; Malone, Misti L; Reed, Terrie L; Fukaya, Rie; Lookstein, Robert; Handa, Nobuhiro; Aronow, Herbert D; Bertges, Daniel J; Jaff, Michael R; Tsai, Thomas T; Smale, Joshua A; Zaugg, Margo J; Thatcher, Robert J; Cronenwett, Jack L; Nc, Durham; Md, Silver Spring; Japan, Tokyo; Ny, New York; Ri, Providence; Vt, Burlington; Mass, Newton; Colo, Denver; Ariz, Tempe; Calif, Santa Clara; Minn, Minneapolis; Nh, Lebanon

2018-01-25

The current state of evaluating patients with peripheral artery disease and more specifically of evaluating medical devices used for peripheral vascular intervention (PVI) remains challenging because of the heterogeneity of the disease process, the multiple physician specialties that perform PVI, the multitude of devices available to treat peripheral artery disease, and the lack of consensus about the best treatment approaches. Because PVI core data elements are not standardized across clinical care, clinical trials, and registries, aggregation of data across different data sources and physician specialties is currently not feasible.Methods and Results:Under the auspices of the U.S. Food and Drug Administration's Medical Device Epidemiology Network initiative-and its PASSION (Predictable and Sustainable Implementation of the National Registries) program, in conjunction with other efforts to align clinical data standards-the Registry Assessment of Peripheral Interventional Devices (RAPID) workgroup was convened. RAPID is a collaborative, multidisciplinary effort to develop a consensus lexicon and to promote interoperability across clinical care, clinical trials, and national and international registries of PVI. The current manuscript presents the initial work from RAPID to standardize clinical data elements and definitions, to establish a framework within electronic health records and health information technology procedural reporting systems, and to implement an informatics-based approach to promote the conduct of pragmatic clinical trials and registry efforts in PVI. Ultimately, we hope this work will facilitate and improve device evaluation and surveillance for patients, clinicians, health outcomes researchers, industry, policymakers, and regulators.

Protocol for Uniformly Measuring and Expressing the Performance of Energy Storage Systems

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

Conover, David R.; Crawford, Alasdair J.; Fuller, Jason

This Protocol provides a set of “best practices” for characterizing energy storage systems (ESSs) and measuring and reporting their performance. It serves as a basis for assessing how an ESS will perform with respect to key performance attributes relevant to different applications. It is intended to provide a valid and accurate basis for the comparison of different ESSs. By achieving the stated purpose, the Protocol will enable more informed decision-making in the selection of ESSs for various stationary applications. The Protocol identifies general information and technical specifications relevant in describing an ESS and also defines a set of test, measurement,more » and evaluation criteria with which to express the performance of ESSs that are intended for energy-intensive and/or power-intensive stationary applications. An ESS includes a storage device, battery management system, and any power conversion systems installed with the storage device. The Protocol is agnostic with respect to the storage technology and the size and rating of the ESS. The Protocol does not apply to single-use storage devices and storage devices that are not coupled with power conversion systems, nor does it address safety, security, or operations and maintenance of ESSs, or provide any pass/fail criteria.« less

Stretchable, Twisted Conductive Microtubules for Wearable Computing, Robotics, Electronics, and Healthcare.

PubMed

Do, Thanh Nho; Visell, Yon

2017-05-11

Stretchable and flexible multifunctional electronic components, including sensors and actuators, have received increasing attention in robotics, electronics, wearable, and healthcare applications. Despite advances, it has remained challenging to design analogs of many electronic components to be highly stretchable, to be efficient to fabricate, and to provide control over electronic performance. Here, we describe highly elastic sensors and interconnects formed from thin, twisted conductive microtubules. These devices consist of twisted assemblies of thin, highly stretchable (>400%) elastomer tubules filled with liquid conductor (eutectic gallium indium, EGaIn), and fabricated using a simple roller coating process. As we demonstrate, these devices can operate as multimodal sensors for strain, rotation, contact force, or contact location. We also show that, through twisting, it is possible to control their mechanical performance and electronic sensitivity. In extensive experiments, we have evaluated the capabilities of these devices, and have prototyped an array of applications in several domains of stretchable and wearable electronics. These devices provide a novel, low cost solution for high performance stretchable electronics with broad applications in industry, healthcare, and consumer electronics, to emerging product categories of high potential economic and societal significance.

Application of the moving-actuator type pump as a ventricular assist device: in vitro and in vivo studies.

PubMed

Lee, H S; Rho, Y R; Park, C Y; Hwang, C M; Kim, W G; Sun, K; Choi, M J; Lee, K K; Cheong, J T; Shim, E B; Min, B G

2002-06-01

A moving actuator type pump has been developed as a multifunctional Korean artificial heart (AnyHeart). The pump consists of a moving actuator as an energy converter, right and left sacs, polymer (or mechanical) valves, and a rigid polyurethane housing. The actuator containing a brushless DC motor moves back and forth on an epicyclical gear train to produce a pendular motion, which compresses both sacs alternately. Of its versatile functions of ventricular assist device and total artificial heart use, we have evaluated the system performance as a single or biventricular assist device through in vitro and in vivo experiments. Pump performance and anatomical feasibility were tested using various animals of different sizes. In the case of single ventricular assist device (VAD) use, one of the sacs remained empty and a mini-compliance chamber was attached to either an outflow or inflow port of the unused sac. The in vitro and in vivo studies show acceptable performance and pump behavior. Further extensive study is required to proceed to human application.

Regulatory perspectives and research activities at the FDA on the use of phantoms with in vivo diagnostic devices

NASA Astrophysics Data System (ADS)

Agrawal, Anant; Gavrielides, Marios A.; Weininger, Sandy; Chakrabarti, Kish; Pfefer, Joshua

2008-02-01

For a number of years, phantoms have been used to optimize device parameters and validate performance in the primary medical imaging modalities (CT, MRI, PET/SPECT, ultrasound). Furthermore, the FDA under the Mammography Quality Standards Act (MQSA) requires image quality evaluation of mammography systems using FDA-approved phantoms. The oldest quantitative optical diagnostic technology, pulse oximetry, also benefits from the use of active phantoms known as patient simulators to validate certain performance characteristics under different clinically-relevant conditions. As such, guidance provided by the FDA to its staff and to industry on the contents of pre-market notification and approval submissions includes suggestions on how to incorporate the appropriate phantoms in establishing device effectiveness. Research at the FDA supports regulatory statements on the use of phantoms by investigating how phantoms can be designed, characterized, and utilized to determine critical device performance characteristics. These examples provide a model for how novel techniques in the rapidly growing field of optical diagnostics can use phantoms during pre- and post-market regulatory testing.

Kaiser Permanente implant registries benefit patient safety, quality improvement, cost-effectiveness.

PubMed

Paxton, Elizabeth W; Kiley, Mary-Lou; Love, Rebecca; Barber, Thomas C; Funahashi, Tadashi T; Inacio, Maria C S

2013-06-01

In response to the increased volume, risk, and cost of medical devices, in 2001 Kaiser Permanente (KP) developed implant registries to enhance patient safety and quality, and to evaluate cost-effectiveness. Using an integrated electronic health record system, administrative databases, and other institutional databases, orthopedic, cardiology, and vascular implant registries were developed in 2001, 2006, and 2011, respectively. These registries monitor patients, implants, clinical practices, and surgical outcomes for KP's 9 million members. Critical to registry success is surgeon leadership and engagement; each geographical region has a surgeon champion who provides feedback on registry initiatives and disseminates registry findings. The registries enhance patient safety by providing a variety of clinical decision tools such as risk calculators, quality reports, risk-adjusted medical center reports, summaries of surgeon data, and infection control reports to registry stakeholders. The registries are used to immediately identify patients with recalled devices, evaluate new and established device technology, and identify outlier implants. The registries contribute to cost-effectiveness initiatives through collaboration with sourcing and contracting groups and confirming adherence to device formulary guidelines. Research studies based on registry data have directly influenced clinical best practices. Registries are important tools to evaluate longitudinal device performance and safety, study the clinical indications for and outcomes of device implantation, respond promptly to recalls and advisories, and contribute to the overall high quality of care of our patients.

Performance of quantum annealing on random Ising problems implemented using the D-Wave Two

NASA Astrophysics Data System (ADS)

Wang, Zhihui; Job, Joshua; Rønnow, Troels F.; Troyer, Matthias; Lidar, Daniel A.; USC Collaboration; ETH Collaboration

2014-03-01

Detecting a possible speedup of quantum annealing compared to classical algorithms is a pressing task in experimental adiabatic quantum computing. In this talk, we discuss the performance of the D-Wave Two quantum annealing device on Ising spin glass problems. The expected time to solution for the device to solve random instances with up to 503 spins and with specified coupling ranges is evaluated while carefully addressing the issue of statistical errors. We perform a systematic comparison of the expected time to solution between the D-Wave Two and classical stochastic solvers, specifically simulated annealing, and simulated quantum annealing based on quantum Monte Carlo, and discuss the question of speedup.

Evaluation of retroreflectometers.

DOT National Transportation Integrated Search

2002-08-01

This project performed field-testing and analysis of two pavement marking retroreflectometers: the Laserlux and the : LTL2000. The Laserlux is a vehiclemounted device that takes readings at driving speed and produces : computerized output. The LTL...

Evaluation of control and display configurations for helicopter shipboard operations

NASA Technical Reports Server (NTRS)

Paulk, C. H., Jr.; Donley, S. T.; Hollis, M. K.

1983-01-01

A simulation evaluation of several approach and landing flight-control configurations and of two out-of-the-cockpit display devices (a head-up display and a helmet-mounted display) was performed for the task of landing a helicopter on a destroyer in adverse weather. The results indicated that the ship airwake turbulence was the most significant environmental variable affecting hover performance. In addition, to achieve adequate landing performance, attitude-command control compensation was required for the pilot regardless of the display used. For improved performance with reduced pilot effort, a velocity-command, position-hold control system was desired.

Benchmarking desktop and mobile handwriting across COTS devices: The e-BioSign biometric database

PubMed Central

Tolosana, Ruben; Vera-Rodriguez, Ruben; Fierrez, Julian; Morales, Aythami; Ortega-Garcia, Javier

2017-01-01

This paper describes the design, acquisition process and baseline evaluation of the new e-BioSign database, which includes dynamic signature and handwriting information. Data is acquired from 5 different COTS devices: three Wacom devices (STU-500, STU-530 and DTU-1031) specifically designed to capture dynamic signatures and handwriting, and two general purpose tablets (Samsung Galaxy Note 10.1 and Samsung ATIV 7). For the two Samsung tablets, data is collected using both pen stylus and also the finger in order to study the performance of signature verification in a mobile scenario. Data was collected in two sessions for 65 subjects, and includes dynamic information of the signature, the full name and alpha numeric sequences. Skilled forgeries were also performed for signatures and full names. We also report a benchmark evaluation based on e-BioSign for person verification under three different real scenarios: 1) intra-device, 2) inter-device, and 3) mixed writing-tool. We have experimented the proposed benchmark using the main existing approaches for signature verification: feature- and time functions-based. As a result, new insights into the problem of signature biometrics in sensor-interoperable scenarios have been obtained, namely: the importance of specific methods for dealing with device interoperability, and the necessity of a deeper analysis on signatures acquired using the finger as the writing tool. This e-BioSign public database allows the research community to: 1) further analyse and develop signature verification systems in realistic scenarios, and 2) investigate towards a better understanding of the nature of the human handwriting when captured using electronic COTS devices in realistic conditions. PMID:28475590

Benchmarking desktop and mobile handwriting across COTS devices: The e-BioSign biometric database.

PubMed

Tolosana, Ruben; Vera-Rodriguez, Ruben; Fierrez, Julian; Morales, Aythami; Ortega-Garcia, Javier

2017-01-01

This paper describes the design, acquisition process and baseline evaluation of the new e-BioSign database, which includes dynamic signature and handwriting information. Data is acquired from 5 different COTS devices: three Wacom devices (STU-500, STU-530 and DTU-1031) specifically designed to capture dynamic signatures and handwriting, and two general purpose tablets (Samsung Galaxy Note 10.1 and Samsung ATIV 7). For the two Samsung tablets, data is collected using both pen stylus and also the finger in order to study the performance of signature verification in a mobile scenario. Data was collected in two sessions for 65 subjects, and includes dynamic information of the signature, the full name and alpha numeric sequences. Skilled forgeries were also performed for signatures and full names. We also report a benchmark evaluation based on e-BioSign for person verification under three different real scenarios: 1) intra-device, 2) inter-device, and 3) mixed writing-tool. We have experimented the proposed benchmark using the main existing approaches for signature verification: feature- and time functions-based. As a result, new insights into the problem of signature biometrics in sensor-interoperable scenarios have been obtained, namely: the importance of specific methods for dealing with device interoperability, and the necessity of a deeper analysis on signatures acquired using the finger as the writing tool. This e-BioSign public database allows the research community to: 1) further analyse and develop signature verification systems in realistic scenarios, and 2) investigate towards a better understanding of the nature of the human handwriting when captured using electronic COTS devices in realistic conditions.

Detection of Apical Root Cracks Using Spectral Domain and Swept-source Optical Coherence Tomography.

PubMed

de Oliveira, Bruna Paloma; Câmara, Andréa Cruz; Duarte, Daniel Amancio; Gomes, Anderson Stevens Leonidas; Heck, Richard John; Antonino, Antonio Celso Dantas; Aguiar, Carlos Menezes

2017-07-01

This study aimed to evaluate the ability of 2 optical coherence tomographic (OCT) systems to detect apical dentinal microcracks. Twenty extracted human single-rooted mandibular incisors were selected. After root canal preparation with an R40 Reciproc file (VDW, Munich, Germany), the specimens presenting apical microcracks were identified using micro-computed tomographic (micro-CT) scanning as the gold standard. Then, the apical portions of the roots were imaged with spectral domain OCT (SD-OCT) and swept-source OCT systems, and the resulting images were blindly evaluated by 3 independent examiners to detect microcracks. The diagnostic performance of each OCT device was calculated, and statistical analysis was performed. Based on the micro-CT images, 12 (60%) roots presented dentinal microcracks in the apical region. The images generated by the OCT systems were able to show microcrack lines at the same location as the corresponding micro-CT cross sections. Although the diagnostic performance of the SD-OCT device was superior, there were no statistically significant differences between the 2 OCT devices (P > .05). Interexaminer agreement was substantial to almost perfect for the SD-OCT system and moderate to almost perfect for the swept-source OCT system, whereas intraexaminer agreement was substantial to almost perfect for both OCT devices. The detection ability verified for both OCT systems renders them promising tools for the diagnosis of apical microcracks. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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

Bouchier, F.; Ahrens, J.S.; Wells, G.

One thing that all access control applications have in common is the need to identify those individuals authorized to gain access to an area. Traditionally, the identification is based on something that person possesses, such as a key or badge, or something they know, such as a PIN or password. Biometric identifiers make their decisions based on the physiological or behavioral characteristics of individuals. The potential of biometrics devices to positively identify individuals has made them attractive for use in access control and computer security applications. However, no systems perform perfectly, so it is important to understand what a biometricmore » device`s performance is under real world conditions before deciding to implement one in an access control system. This paper will describe the evaluation of a prototype biometric identifier provided by IriScan Incorporated. This identifier was developed to recognize individual human beings based on the distinctive visual characteristics of the irises of their eyes. The main goal of the evaluation was to determine whether the system has potential as an access control device within the Department of Energy (DOE). The primary interest was an estimate of the accuracy of the system in terms of false accept and false reject rates. Data was also collected to estimate throughput time and user acceptability. The performance of the system during the test will be discussed. Lessons learned during the test which may aid in further testing and simplify implementation of a production system will also be discussed.« less

Pulse Transit Time Measurement Using Seismocardiogram, Photoplethysmogram, and Acoustic Recordings: Evaluation and Comparison.

PubMed

Yang, Chenxi; Tavassolian, Negar

2018-05-01

This work proposes a novel method of pulse transit time (PTT) measurement. The proximal arterial location data are collected from seismocardiogram (SCG) recordings by placing a micro-electromechanical accelerometer on the chest wall. The distal arterial location data are recorded using an acoustic sensor placed inside the ear. The performance of distal location recordings is evaluated by comparing SCG-acoustic and SCG-photoplethysmogram (PPG) measurements. PPG and acoustic performances under motion noise are also compared. Experimental results suggest comparable performances for the acoustic-based and PPG-based devices. The feasibility of each PTT measurement method is validated for blood pressure evaluations and its limitations are analyzed.

Monte-Carlo study of the influence of backscattered electrons on the transmission of a mini-orange β spectrometer

NASA Astrophysics Data System (ADS)

Detistov, Pavel; Balabanski, Dimiter L.

2015-04-01

This work work is a part of the performance investigation of the recently constructed Mini-Orange beta spectrometer. The spectrometer has eight different configurations using three different magnet shapes and combination of three, four, and six magnet pieces allowing detection of electrons in wide kinetic energy range. The performance of the device is studied using the GEANT4 simulation tool. Evaluation of the device's basic parameters has been made, paying special attention to the backscattering, for which a study of the dependence of this process on the energy and the angle is made.

Influence of different types of mouthguards on strength and performance of collegiate athletes: a controlled-randomized trial.

PubMed

Duddy, Fergus A; Weissman, Jake; Lee, Rich A; Paranjpe, Avina; Johnson, James D; Cohenca, Nestor

2012-08-01

Prevention of traumatic dental injuries relies on the identification of etiologic factors and the use of protective devices during contact sports. Mouthguards are considered to be an effective and cost-efficient device aimed at buffering the impacts or blows that might otherwise cause moderate to severe dental and maxillofacial injuries. Interestingly, besides their role in preventing injury, some authors claim that mouthguards can enhance athletic performance. Thus, the purpose of this controlled randomized trial was to evaluate and compare the effect of two different types of mouthguards on the athletic performance and strength of collegiate athletes. Eighteen college athletes ranging from 19 to 23 years participated in this study. Devices tested in this study included an over-the-counter boil-and-bite mouthguard (O-Flow™ Max Under Armour®) (UA) and a custom-made mouthguard (CM). Physical tests were carefully selected by the head athletic trainer and aimed at evaluating the strength and performance. The following sequence was carried out on each test day: (i) 3-stroke maximum power ergometer test, (ii) 1-min ergometer test, and (iii) a 1600-m run. A random assignment was developed to test all three experimental groups on each test day. Following the tests, each athlete completed a brief anonymous survey aimed at evaluating the athletes' overall satisfaction with each type of mouthguard. Custom-made mouthguards had no detrimental effect on athletic strength and performance and were reported by the athletes as being comfortable and not causing difficulty in breathing. In contrast, boil-and-bite mouthguards did not perform as well and were reported as being uncomfortable and causing breathing difficulties. Based on the results of this study, the use of custom-made mouthguards should be encouraged in contact sports as a protective measure, without concern for any negative effect on the athletic performance of the athletes. © 2012 John Wiley & Sons A/S.

Usefulness of vessel-sealing devices for peripartum hysterectomy: a retrospective cohort study.

PubMed

Rossetti, Diego; Vitale, Salvatore Giovanni; Bogani, Giorgio; Rapisarda, Agnese Maria Chiara; Gulino, Ferdinando Antonio; Frigerio, Luigi

2015-09-01

To evaluate the feasibility to perform peripartum hysterectomy (PH) with the introduction of LigaSure™ vessels-sealing device (LVSD) and how it influenced the surgical outcomes. We retrospectively evaluated procedures and outcome of women undergoing PH during the period between January 2001 and October 2013. Perioperative surgical results of patients undergoing PH using LVSD were compared to patients undergoing PH without LVSD. Forty-nine subjects had PH during the study period. Twenty (41%) hysterectomies were performed for placenta accreta, 8 (16%) for placenta previa, 21 (43%) for atony. Twenty-three subjects had PH using LVSD and 26 subjects had hysterectomy without the use of this device. We observe significant differences in estimated blood loss (p = 0.001), massive blood transfusions (>10 units RBC) (p = 0.025), operative time (p = 0.06). No difference in term of hospital stay and complications were observed (p = 0.78 and p = 0.35). One patient for each group had intraoperative complication (p = 0.9). The use of LVSD during PH does not increase operative complications, blood loss, and operative time in comparison to standard procedure.

An evaluation of strain measuring devices for ceramic composites

NASA Technical Reports Server (NTRS)

Gyekenyesi, John Z.; Bartolotta, Paul A.

1991-01-01

A series of tensile tests was conducted on SiC/reaction bonded silicon nitrides (RBSN) composites using different methods of strain measurement. The tests were used to find the optimum strain sensing device for use with continuous fiber reinforced ceramic matrix composites in ambient and high temperature environments. Bonded resistance gages were found to offer excellent performance for room temperature tests. The clip-on gage offers the same performance, but less time is required for mounting it to the specimen. Low contact force extensometers track the strain with acceptable results at high specimen temperatures. Silicon carbide rods with knife edges are preferred. The edges must be kept sharp. The strain measuring devices should be mounted on the flat side of the specimen. This is in contrast to mounting on the rough thickness side.

An evaluation of strain measuring devices for ceramic composites

NASA Technical Reports Server (NTRS)

Gyekenyesi, John Z.; Bartolotta, Paul A.

1992-01-01

A series of tensile tests were conducted on SiC/RBSN composites using different methods of strain measurement. The tests were used to find the optimum strain sensing device for use with continuous fiber reinforced ceramic matrix composites in ambient and high temperature environments. Bonded resistance strain gages were found to offer excellent performance for room temperature tests. The clip-on gage offers the same performance but significantly less time is required for mounting it to the specimen. Low contact force extensometers track the strain with acceptable results at high specimen temperatures. Silicon carbide rods with knife edges are preferred. The edges must be kept sharp. The strain measuring devices should be mounted on the flat side of the specimen. This is in contrast to mounting on the rough thickness side.

Power Consumption Analysis of Operating Systems for Wireless Sensor Networks

PubMed Central

Lajara, Rafael; Pelegrí-Sebastiá, José; Perez Solano, Juan J.

2010-01-01

In this paper four wireless sensor network operating systems are compared in terms of power consumption. The analysis takes into account the most common operating systems—TinyOS v1.0, TinyOS v2.0, Mantis and Contiki—running on Tmote Sky and MICAz devices. With the objective of ensuring a fair evaluation, a benchmark composed of four applications has been developed, covering the most typical tasks that a Wireless Sensor Network performs. The results show the instant and average current consumption of the devices during the execution of these applications. The experimental measurements provide a good insight into the power mode in which the device components are running at every moment, and they can be used to compare the performance of different operating systems executing the same tasks. PMID:22219688

Power consumption analysis of operating systems for wireless sensor networks.

PubMed

Lajara, Rafael; Pelegrí-Sebastiá, José; Perez Solano, Juan J

2010-01-01

In this paper four wireless sensor network operating systems are compared in terms of power consumption. The analysis takes into account the most common operating systems--TinyOS v1.0, TinyOS v2.0, Mantis and Contiki--running on Tmote Sky and MICAz devices. With the objective of ensuring a fair evaluation, a benchmark composed of four applications has been developed, covering the most typical tasks that a Wireless Sensor Network performs. The results show the instant and average current consumption of the devices during the execution of these applications. The experimental measurements provide a good insight into the power mode in which the device components are running at every moment, and they can be used to compare the performance of different operating systems executing the same tasks.

Optimization and evaluation of the human fall detection system

NASA Astrophysics Data System (ADS)

Alzoubi, Hadeel; Ramzan, Naeem; Shahriar, Hasan; Alzubi, Raid; Gibson, Ryan; Amira, Abbes

2016-10-01

Falls are the most critical health problem for elderly people, which are often, cause significant injuries. To tackle a serious risk that made by the fall, we develop an automatic wearable fall detection system utilizing two devices (mobile phone and wireless sensor) based on three axes accelerometer signals. The goal of this study is to find an effective machine learning method that distinguish falls from activities of daily living (ADL) using only a single triaxial accelerometer. In addition, comparing the performance results for wearable sensor and mobile device data .The proposed model detects the fall by using seven different classifiers and the significant performance is demonstrated using accuracy, recall, precision and F-measure. Our model obtained accuracy over 99% on wearable device data and over 97% on mobile phone data.

Design and performance of 4 x 5120-element visible and 2 x 2560-element shortwave infrared multispectral focal planes

NASA Astrophysics Data System (ADS)

Tower, J. R.; Cope, A. D.; Pellon, L. E.; McCarthy, B. M.; Strong, R. T.

1986-06-01

Two solid-state sensors for use in remote sensing instruments operating in the pushbroom mode are examined. The design and characteristics of the visible/near-infrared (VIS/NIR) device and the short-wavelength infrared (SWIR) device are described. The VIS/NIR is a CCD imager with four parallel sensor lines, each 1024 pixel long; the chip design and filter system of the VIS/NIR are studied. The performance of the VIS/NIR sensor with mask and its system performance are measured. The SWIR is a dual-band line imager consisting of palladium silicide Schottky-barrier detectors coupled to CCD multiplexers; the performance of the device is analyzed. The substrate materials and layout designs used to assemble the 4 x 5120-element VIS/NIR array and the 2 x 2560-element SWIR array are discussed, and the planarity of the butted arrays are verified using a profilometer. The optical and electrical characteristics, and the placement and butting accuracy of the arrays are evaluated. It is noted that the arrays met or exceed their expected performance.

A Performance Evaluation of a Lean Reparable Pipeline in Various Demand Environments

DTIC Science & Technology

2004-03-23

of defects (Dennis, 2002:90). Shingo espoused the true goal should be zero defects and to this end, invented the poka - yoke , or a simple, inexpensive...92). Despite the inability to eliminate human errors, poka - yoke devices can still enable the elimination of production defects (Dennis, 2002:91... Poka - yoke devices are essentially foolproofing mechanisms which incorporate automatic inspection into the production process. Despite the fact

Noninvasive type 2 diabetes screening: superior sensitivity to fasting plasma glucose and A1C.

PubMed

Maynard, John D; Rohrscheib, Mark; Way, Jeffrey F; Nguyen, Catriona M; Ediger, Marwood N

2007-05-01

This study compared the performance of a novel noninvasive technology to fasting plasma glucose (FPG) and A1C tests for detecting undiagnosed diabetes and impaired glucose tolerance. The design was a head-to-head evaluation in a naïve population. Consented subjects received FPG and A1C tests and an oral glucose tolerance test (OGTT). Subjects were also measured by a noninvasive device that detects the fluorescence of skin advanced glycation end products. A total of 351 subjects participated. Subjects with 2-h OGTT values > or = 140 mg/dl defined the positive screening class. A total of 84 subjects (23.9% prevalence) screened positive. The performances of the noninvasive device, FPG, and A1C were evaluated for sensitivity and specificity against this classification. At the impaired fasting glucose threshold (FPG = 100 mg/dl), the FPG testing sensitivity was 58% and the specificity was 77.4%. At that same specificity, the sensitivity for A1C testing was 63.8%, while the noninvasive testing sensitivity was 74.7%. The sensitivity advantage of the noninvasive device over both blood tests for detecting diabetes and precursors was statistically significant (P < 0.05). The noninvasive technology showed clinical performance advantages over both FPG and A1C testing. The sensitivity differential indicated that the noninvasive device is capable of identifying 28.8% more individuals in the OGTT-defined positive screening class than FPG testing and 17.1% more than A1C testing. The combination of higher sensitivity and greater convenience--rapid results with no fasting or blood draws--makes the device well suited for opportunistic screening.

Blood collection tubes as medical devices: The potential to affect assays and proposed verification and validation processes for the clinical laboratory.

PubMed

Bowen, Raffick A R; Adcock, Dorothy M

2016-12-01

Blood collection tubes (BCTs) are an often under-recognized variable in the preanalytical phase of clinical laboratory testing. Unfortunately, even the best-designed and manufactured BCTs may not work well in all clinical settings. Clinical laboratories, in collaboration with healthcare providers, should carefully evaluate BCTs prior to putting them into clinical use to determine their limitations and ensure that patients are not placed at risk because of inaccuracies due to poor tube performance. Selection of the best BCTs can be achieved through comparing advertising materials, reviewing the literature, observing the device at a scientific meeting, receiving a demonstration, evaluating the device under simulated conditions, or testing the device with patient samples. Although many publications have discussed method validations, few detail how to perform experiments for tube verification and validation. This article highlights the most common and impactful variables related to BCTs and discusses the validation studies that a typical clinical laboratory should perform when selecting BCTs. We also present a brief review of how in vitro diagnostic devices, particularly BCTs, are regulated in the United States, the European Union, and Canada. The verification and validation of BCTs will help to avoid the economic and human costs associated with incorrect test results, including poor patient care, unnecessary testing, and delays in test results. We urge laboratorians, tube manufacturers, diagnostic companies, and other researchers to take all the necessary steps to protect against the adverse effects of BCT components and their additives on clinical assays. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Kinematic, muscular, and metabolic responses during exoskeletal-, elliptical-, or therapist-assisted stepping in people with incomplete spinal cord injury.

PubMed

Hornby, T George; Kinnaird, Catherine R; Holleran, Carey L; Rafferty, Miriam R; Rodriguez, Kelly S; Cain, Julie B

2012-10-01

Robotic-assisted locomotor training has demonstrated some efficacy in individuals with neurological injury and is slowly gaining clinical acceptance. Both exoskeletal devices, which control individual joint movements, and elliptical devices, which control endpoint trajectories, have been utilized with specific patient populations and are available commercially. No studies have directly compared training efficacy or patient performance during stepping between devices. The purpose of this study was to evaluate kinematic, electromyographic (EMG), and metabolic responses during elliptical- and exoskeletal-assisted stepping in individuals with incomplete spinal cord injury (SCI) compared with therapist-assisted stepping. Design A prospective, cross-sectional, repeated-measures design was used. Participants with incomplete SCI (n=11) performed 3 separate bouts of exoskeletal-, elliptical-, or therapist-assisted stepping. Unilateral hip and knee sagittal-plane kinematics, lower-limb EMG recordings, and oxygen consumption were compared across stepping conditions and with control participants (n=10) during treadmill stepping. Exoskeletal stepping kinematics closely approximated normal gait patterns, whereas significantly greater hip and knee flexion postures were observed during elliptical-assisted stepping. Measures of kinematic variability indicated consistent patterns in control participants and during exoskeletal-assisted stepping, whereas therapist- and elliptical-assisted stepping kinematics were more variable. Despite specific differences, EMG patterns generally were similar across stepping conditions in the participants with SCI. In contrast, oxygen consumption was consistently greater during therapist-assisted stepping. Limitations Limitations included a small sample size, lack of ability to evaluate kinetics during stepping, unilateral EMG recordings, and sagittal-plane kinematics. Despite specific differences in kinematics and EMG activity, metabolic activity was similar during stepping in each robotic device. Understanding potential differences and similarities in stepping performance with robotic assistance may be important in delivery of repeated locomotor training using robotic or therapist assistance and for consumers of robotic devices.

Effects of self-assembled monolayer structural order, surface homogeneity and surface energy on pentacene morphology and thin film transistor device performance.

PubMed

Hutchins, Daniel Orrin; Weidner, Tobias; Baio, Joe; Polishak, Brent; Acton, Orb; Cernetic, Nathan; Ma, Hong; Jen, Alex K-Y

2013-01-04

A systematic study of six phosphonic acid (PA) self-assembled monolayers (SAMs) with tailored molecular structures is performed to evaluate their effectiveness as dielectric modifying layers in organic field-effect transistors (OFETs) and determine the relationship between SAM structural order, surface homogeneity, and surface energy in dictating device performance. SAM structures and surface properties are examined by near edge X-ray absorption fine structure (NEXAFS) spectroscopy, contact angle goniometry, and atomic force microscopy (AFM). Top-contact pentacene OFET devices are fabricated on SAM modified Si with a thermally grown oxide layer as a dielectric. For less ordered methyl- and phenyl-terminated alkyl ~(CH 2 ) 12 PA SAMs of varying surface energies, pentacene OFETs show high charge carrier mobilities up to 4.1 cm 2 V -1 s -1 . It is hypothesized that for these SAMs, mitigation of molecular scale roughness and subsequent control of surface homogeneity allow for large pentacene grain growth leading to high performance pentacene OFET devices. PA SAMs that contain bulky terminal groups or are highly crystalline in nature do not allow for a homogenous surface at a molecular level and result in charge carrier mobilities of 1.3 cm 2 V -1 s -1 or less. For all molecules used in this study, no causal relationship between SAM surface energy and charge carrier mobility in pentacene FET devices is observed.

Effects of self-assembled monolayer structural order, surface homogeneity and surface energy on pentacene morphology and thin film transistor device performance

PubMed Central

Hutchins, Daniel Orrin; Weidner, Tobias; Baio, Joe; Polishak, Brent; Acton, Orb; Cernetic, Nathan; Ma, Hong; Jen, Alex K.-Y.

2013-01-01

A systematic study of six phosphonic acid (PA) self-assembled monolayers (SAMs) with tailored molecular structures is performed to evaluate their effectiveness as dielectric modifying layers in organic field-effect transistors (OFETs) and determine the relationship between SAM structural order, surface homogeneity, and surface energy in dictating device performance. SAM structures and surface properties are examined by near edge X-ray absorption fine structure (NEXAFS) spectroscopy, contact angle goniometry, and atomic force microscopy (AFM). Top-contact pentacene OFET devices are fabricated on SAM modified Si with a thermally grown oxide layer as a dielectric. For less ordered methyl- and phenyl-terminated alkyl ~(CH2)12 PA SAMs of varying surface energies, pentacene OFETs show high charge carrier mobilities up to 4.1 cm2 V−1 s−1. It is hypothesized that for these SAMs, mitigation of molecular scale roughness and subsequent control of surface homogeneity allow for large pentacene grain growth leading to high performance pentacene OFET devices. PA SAMs that contain bulky terminal groups or are highly crystalline in nature do not allow for a homogenous surface at a molecular level and result in charge carrier mobilities of 1.3 cm2 V−1 s−1 or less. For all molecules used in this study, no causal relationship between SAM surface energy and charge carrier mobility in pentacene FET devices is observed. PMID:24086795

Performance evaluation of traffic sensing and control devices.

DOT National Transportation Integrated Search

2011-01-01

High quality vehicle detection is essential to properly operate actuated phases at traffic signals and to facilitate effective : management of technician and engineering resources. INDOT operates over 2600 traffic signal controllers, approximately 20...

A 3-RSR Haptic Wearable Device for Rendering Fingertip Contact Forces.

PubMed

Leonardis, Daniele; Solazzi, Massimiliano; Bortone, Ilaria; Frisoli, Antonio

2017-01-01

A novel wearable haptic device for modulating contact forces at the fingertip is presented. Rendering of forces by skin deformation in three degrees of freedom (DoF), with contact-no contact capabilities, was implemented through rigid parallel kinematics. The novel asymmetrical three revolute-spherical-revolute (3-RSR) configuration allowed compact dimensions with minimum encumbrance of the hand workspace. The device was designed to render constant to low frequency deformation of the fingerpad in three DoF, combining light weight with relatively high output forces. A differential method for solving the non-trivial inverse kinematics is proposed and implemented in real time for controlling the device. The first experimental activity evaluated discrimination of different fingerpad stretch directions in a group of five subjects. The second experiment, enrolling 19 subjects, evaluated cutaneous feedback provided in a virtual pick-and-place manipulation task. Stiffness of the fingerpad plus device was measured and used to calibrate the physics of the virtual environment. The third experiment with 10 subjects evaluated interaction forces in a virtual lift-and-hold task. Although with different performance in the two manipulation experiments, overall results show that participants better controlled interaction forces when the cutaneous feedback was active, with significant differences between the visual and visuo-haptic experimental conditions.

The history of anaesthetic equipment evaluation in the United Kingdom: lessons for developing future strategy.

PubMed

Wilkes, A R; Pandit, J J; O'Sullivan, E

2011-12-01

Recent guidance published by the Association of Anaesthetists of Great Britain and Ireland encourages the purchase of equipment based on evidence of safety and performance. For many years, evidence of the safety and performance of anaesthetic equipment was published by various government departments and agencies. However, these schemes were gradually eroded over time such that many devices entered the market with little or no clinical evidence of their efficacy. This recently led to the Difficult Airway Society's issuing guidance to its members on how best to select new airway devices; guidance that was based on the available evidence. This article provides a short history of the evaluation of anaesthetic equipment in the United Kingdom. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

Performances of different global positioning system devices for time-location tracking in air pollution epidemiological studies.

PubMed

Wu, Jun; Jiang, Chengsheng; Liu, Zhen; Houston, Douglas; Jaimes, Guillermo; McConnell, Rob

2010-11-23

People's time-location patterns are important in air pollution exposure assessment because pollution levels may vary considerably by location. A growing number of studies are using global positioning systems (GPS) to track people's time-location patterns. Many portable GPS units that archive location are commercially available at a cost that makes their use feasible for epidemiological studies. We evaluated the performance of five portable GPS data loggers and two GPS cell phones by examining positional accuracy in typical locations (indoor, outdoor, in-vehicle) and factors that influence satellite reception (building material, building type), acquisition time (cold and warm start), battery life, and adequacy of memory for data storage. We examined stationary locations (eg, indoor, outdoor) and mobile environments (eg, walking, traveling by vehicle or bus) and compared GPS locations to highly-resolved US Geological Survey (USGS) and Digital Orthophoto Quarter Quadrangle (DOQQ) maps. The battery life of our tested instruments ranged from <9 hours to 48 hours. The acquisition of location time after startup ranged from a few seconds to >20 minutes and varied significantly by building structure type and by cold or warm start. No GPS device was found to have consistently superior performance with regard to spatial accuracy and signal loss. At fixed outdoor locations, 65%-95% of GPS points fell within 20-m of the corresponding DOQQ locations for all the devices. At fixed indoor locations, 50%-80% of GPS points fell within 20-m of the corresponding DOQQ locations for all the devices except one. Most of the GPS devices performed well during commuting on a freeway, with >80% of points within 10-m of the DOQQ route, but the performance was significantly impacted by surrounding structures on surface streets in highly urbanized areas. All the tested GPS devices had limitations, but we identified several devices which showed promising performance for tracking subjects' time location patterns in epidemiological studies.

Performances of Different Global Positioning System Devices for Time-Location Tracking in Air Pollution Epidemiological Studies

PubMed Central

Wu, Jun; Jiang, Chengsheng; Liu, Zhen; Houston, Douglas; Jaimes, Guillermo; McConnell, Rob

2010-01-01

Background: People’s time-location patterns are important in air pollution exposure assessment because pollution levels may vary considerably by location. A growing number of studies are using global positioning systems (GPS) to track people’s time-location patterns. Many portable GPS units that archive location are commercially available at a cost that makes their use feasible for epidemiological studies. Methods: We evaluated the performance of five portable GPS data loggers and two GPS cell phones by examining positional accuracy in typical locations (indoor, outdoor, in-vehicle) and factors that influence satellite reception (building material, building type), acquisition time (cold and warm start), battery life, and adequacy of memory for data storage. We examined stationary locations (eg, indoor, outdoor) and mobile environments (eg, walking, traveling by vehicle or bus) and compared GPS locations to highly-resolved US Geological Survey (USGS) and Digital Orthophoto Quarter Quadrangle (DOQQ) maps. Results: The battery life of our tested instruments ranged from <9 hours to 48 hours. The acquisition of location time after startup ranged from a few seconds to >20 minutes and varied significantly by building structure type and by cold or warm start. No GPS device was found to have consistently superior performance with regard to spatial accuracy and signal loss. At fixed outdoor locations, 65%–95% of GPS points fell within 20-m of the corresponding DOQQ locations for all the devices. At fixed indoor locations, 50%–80% of GPS points fell within 20-m of the corresponding DOQQ locations for all the devices except one. Most of the GPS devices performed well during commuting on a freeway, with >80% of points within 10-m of the DOQQ route, but the performance was significantly impacted by surrounding structures on surface streets in highly urbanized areas. Conclusions: All the tested GPS devices had limitations, but we identified several devices which showed promising performance for tracking subjects’ time location patterns in epidemiological studies. PMID:21151593

Framework for automatic information extraction from research papers on nanocrystal devices

PubMed Central

Yoshioka, Masaharu; Hara, Shinjiro; Newton, Marcus C

2015-01-01

Summary To support nanocrystal device development, we have been working on a computational framework to utilize information in research papers on nanocrystal devices. We developed an annotated corpus called “ NaDev” (Nanocrystal Device Development) for this purpose. We also proposed an automatic information extraction system called “NaDevEx” (Nanocrystal Device Automatic Information Extraction Framework). NaDevEx aims at extracting information from research papers on nanocrystal devices using the NaDev corpus and machine-learning techniques. However, the characteristics of NaDevEx were not examined in detail. In this paper, we conduct system evaluation experiments for NaDevEx using the NaDev corpus. We discuss three main issues: system performance, compared with human annotators; the effect of paper type (synthesis or characterization) on system performance; and the effects of domain knowledge features (e.g., a chemical named entity recognition system and list of names of physical quantities) on system performance. We found that overall system performance was 89% in precision and 69% in recall. If we consider identification of terms that intersect with correct terms for the same information category as the correct identification, i.e., loose agreement (in many cases, we can find that appropriate head nouns such as temperature or pressure loosely match between two terms), the overall performance is 95% in precision and 74% in recall. The system performance is almost comparable with results of human annotators for information categories with rich domain knowledge information (source material). However, for other information categories, given the relatively large number of terms that exist only in one paper, recall of individual information categories is not high (39–73%); however, precision is better (75–97%). The average performance for synthesis papers is better than that for characterization papers because of the lack of training examples for characterization papers. Based on these results, we discuss future research plans for improving the performance of the system. PMID:26665057

Framework for automatic information extraction from research papers on nanocrystal devices.

PubMed

Dieb, Thaer M; Yoshioka, Masaharu; Hara, Shinjiro; Newton, Marcus C

2015-01-01

To support nanocrystal device development, we have been working on a computational framework to utilize information in research papers on nanocrystal devices. We developed an annotated corpus called " NaDev" (Nanocrystal Device Development) for this purpose. We also proposed an automatic information extraction system called "NaDevEx" (Nanocrystal Device Automatic Information Extraction Framework). NaDevEx aims at extracting information from research papers on nanocrystal devices using the NaDev corpus and machine-learning techniques. However, the characteristics of NaDevEx were not examined in detail. In this paper, we conduct system evaluation experiments for NaDevEx using the NaDev corpus. We discuss three main issues: system performance, compared with human annotators; the effect of paper type (synthesis or characterization) on system performance; and the effects of domain knowledge features (e.g., a chemical named entity recognition system and list of names of physical quantities) on system performance. We found that overall system performance was 89% in precision and 69% in recall. If we consider identification of terms that intersect with correct terms for the same information category as the correct identification, i.e., loose agreement (in many cases, we can find that appropriate head nouns such as temperature or pressure loosely match between two terms), the overall performance is 95% in precision and 74% in recall. The system performance is almost comparable with results of human annotators for information categories with rich domain knowledge information (source material). However, for other information categories, given the relatively large number of terms that exist only in one paper, recall of individual information categories is not high (39-73%); however, precision is better (75-97%). The average performance for synthesis papers is better than that for characterization papers because of the lack of training examples for characterization papers. Based on these results, we discuss future research plans for improving the performance of the system.

A Middleware Based Approach to Dynamically Deploy Location Based Services onto Heterogeneous Mobile Devices Using Bluetooth in Indoor Environment

NASA Astrophysics Data System (ADS)

Sadhukhan, Pampa; Sen, Rijurekha; Das, Pradip K.

Several methods for providing location based service (LBS) to mobile devices in indoor environment using wireless technologies like WLAN, RFID and Bluetooth have been proposed, implemented and evaluated. However, most of them do not focus on heterogeneity of mobile platforms, memory constraint of mobile devices, the adaptability of client or device to the new services it discovers whenever it reaches a new location. In this paper, we have proposed a Middleware based approach of LBS provision in the indoor environment, where a Bluetooth enabled Base Station (BS) detects Bluetooth enabled mobile devices and pushes a proper client application only to those devices that belong to some registered subscriber of LBS. This dynamic deployment enables the mobile clients to access any new service without having preinstalled interface to that service beforehand and thus the client's memory consumption is reduced. Our proposed work also addresses the other issues like authenticating the clients before providing them LBSs and introducing paid services. We have evaluated its performance in term of file transfer time with respect to file size and throughput with respect to distance. Experimental results on service consumption time by the mobile client for different services are also presented.

A Data Encryption Solution for Mobile Health Apps in Cooperation Environments

PubMed Central

Silva, Bruno M; Canelo, Fábio; Lopes, Ivo C; Zhou, Liang

2013-01-01

Background Mobile Health (mHealth) proposes health care delivering anytime and anywhere. It aims to answer several emerging problems in health services, including the increasing number of chronic diseases, high costs on national health services, and the need to provide direct access to health services, regardless of time and place. mHealth systems include the use of mobile devices and apps that interact with patients and caretakers. However, mobile devices present several constraints, such as processor, energy, and storage resource limitations. The constant mobility and often-required Internet connectivity also exposes and compromises the privacy and confidentiality of health information. Objective This paper presents a proposal, construction, performance evaluation, and validation of a data encryption solution for mobile health apps (DE4MHA), considering a novel and early-proposed cooperation strategy. The goal was to present a robust solution based on encryption algorithms that guarantee the best confidentiality, integrity, and authenticity of users health information. In this paper, we presented, explained, evaluated the performance, and discussed the cooperation mechanisms and the proposed encryption solution for mHealth apps. Methods First, we designed and deployed the DE4MHA. Then two studies were performed: (1) study and comparison of symmetric and asymmetric encryption/decryption algorithms in an mHealth app under a cooperation environment, and (2) performance evaluation of the DE4MHA. Its performance was evaluated through a prototype using an mHealth app for obesity prevention and cares, called SapoFit. We then conducted an evaluation study of the mHealth app with cooperation mechanisms and the DE4MHA using real users and a real cooperation scenario. In 5 days, 5 different groups of 7 students selected randomly agreed to use and experiment the SapoFit app using the 7 devices available for trials. Results There were 35 users of SapoFit that participated in this study. The performance evaluation of the app was done using 7 real mobile devices in 5 different days. The results showed that confidentiality and protection of the users’ health information was guaranteed and SapoFit users were able to use the mHealth app with satisfactory quality. Results also showed that the app with the DE4MHA presented nearly the same results as the app without the DE4MHA. The performance evaluation results considered the probability that a request was successfully answered as a function of the number of uncooperative nodes in the network. The service delivery probability decreased with the increase of uncooperative mobile nodes. Using DE4MHA, it was observed that performance presented a slightly worse result. The service average was also slightly worse but practically insignificantly different than with DE4MHA, being considered negligible. Conclusions This paper proposed a data encryption solution for mobile health apps, called DE4MHA. The data encryption algorithm DE4MHA with cooperation mechanisms in mobile health allow users to safely obtain health information with the data being carried securely. These security mechanisms did not deteriorate the overall network performance and the app, maintaining similar performance levels as without the encryption. More importantly, it offers a robust and reliable increase of privacy, confidentiality, integrity, and authenticity of their health information. Although it was experimented on a specific mHealth app, SapoFit, both DE4MHA and the cooperation strategy can be deployed in other mHealth apps. PMID:23624056

A data encryption solution for mobile health apps in cooperation environments.

PubMed

Silva, Bruno M; Rodrigues, Joel J P C; Canelo, Fábio; Lopes, Ivo C; Zhou, Liang

2013-04-25

Mobile Health (mHealth) proposes health care delivering anytime and anywhere. It aims to answer several emerging problems in health services, including the increasing number of chronic diseases, high costs on national health services, and the need to provide direct access to health services, regardless of time and place. mHealth systems include the use of mobile devices and apps that interact with patients and caretakers. However, mobile devices present several constraints, such as processor, energy, and storage resource limitations. The constant mobility and often-required Internet connectivity also exposes and compromises the privacy and confidentiality of health information. This paper presents a proposal, construction, performance evaluation, and validation of a data encryption solution for mobile health apps (DE4MHA), considering a novel and early-proposed cooperation strategy. The goal was to present a robust solution based on encryption algorithms that guarantee the best confidentiality, integrity, and authenticity of users health information. In this paper, we presented, explained, evaluated the performance, and discussed the cooperation mechanisms and the proposed encryption solution for mHealth apps. First, we designed and deployed the DE4MHA. Then two studies were performed: (1) study and comparison of symmetric and asymmetric encryption/decryption algorithms in an mHealth app under a cooperation environment, and (2) performance evaluation of the DE4MHA. Its performance was evaluated through a prototype using an mHealth app for obesity prevention and cares, called SapoFit. We then conducted an evaluation study of the mHealth app with cooperation mechanisms and the DE4MHA using real users and a real cooperation scenario. In 5 days, 5 different groups of 7 students selected randomly agreed to use and experiment the SapoFit app using the 7 devices available for trials. There were 35 users of SapoFit that participated in this study. The performance evaluation of the app was done using 7 real mobile devices in 5 different days. The results showed that confidentiality and protection of the users' health information was guaranteed and SapoFit users were able to use the mHealth app with satisfactory quality. Results also showed that the app with the DE4MHA presented nearly the same results as the app without the DE4MHA. The performance evaluation results considered the probability that a request was successfully answered as a function of the number of uncooperative nodes in the network. The service delivery probability decreased with the increase of uncooperative mobile nodes. Using DE4MHA, it was observed that performance presented a slightly worse result. The service average was also slightly worse but practically insignificantly different than with DE4MHA, being considered negligible. This paper proposed a data encryption solution for mobile health apps, called DE4MHA. The data encryption algorithm DE4MHA with cooperation mechanisms in mobile health allow users to safely obtain health information with the data being carried securely. These security mechanisms did not deteriorate the overall network performance and the app, maintaining similar performance levels as without the encryption. More importantly, it offers a robust and reliable increase of privacy, confidentiality, integrity, and authenticity of their health information. Although it was experimented on a specific mHealth app, SapoFit, both DE4MHA and the cooperation strategy can be deployed in other mHealth apps.

Numerical evaluation of implantable hearing devices using a finite element model of human ear considering viscoelastic properties.

PubMed

Zhang, Jing; Tian, Jiabin; Ta, Na; Huang, Xinsheng; Rao, Zhushi

2016-08-01

Finite element method was employed in this study to analyze the change in performance of implantable hearing devices due to the consideration of soft tissues' viscoelasticity. An integrated finite element model of human ear including the external ear, middle ear and inner ear was first developed via reverse engineering and analyzed by acoustic-structure-fluid coupling. Viscoelastic properties of soft tissues in the middle ear were taken into consideration in this model. The model-derived dynamic responses including middle ear and cochlea functions showed a better agreement with experimental data at high frequencies above 3000 Hz than the Rayleigh-type damping. On this basis, a coupled finite element model consisting of the human ear and a piezoelectric actuator attached to the long process of incus was further constructed. Based on the electromechanical coupling analysis, equivalent sound pressure and power consumption of the actuator corresponding to viscoelasticity and Rayleigh damping were calculated using this model. The analytical results showed that the implant performance of the actuator evaluated using a finite element model considering viscoelastic properties gives a lower output above about 3 kHz than does Rayleigh damping model. Finite element model considering viscoelastic properties was more accurate to numerically evaluate implantable hearing devices. © IMechE 2016.

Computational performance of a smoothed particle hydrodynamics simulation for shared-memory parallel computing

NASA Astrophysics Data System (ADS)

Nishiura, Daisuke; Furuichi, Mikito; Sakaguchi, Hide

2015-09-01

The computational performance of a smoothed particle hydrodynamics (SPH) simulation is investigated for three types of current shared-memory parallel computer devices: many integrated core (MIC) processors, graphics processing units (GPUs), and multi-core CPUs. We are especially interested in efficient shared-memory allocation methods for each chipset, because the efficient data access patterns differ between compute unified device architecture (CUDA) programming for GPUs and OpenMP programming for MIC processors and multi-core CPUs. We first introduce several parallel implementation techniques for the SPH code, and then examine these on our target computer architectures to determine the most effective algorithms for each processor unit. In addition, we evaluate the effective computing performance and power efficiency of the SPH simulation on each architecture, as these are critical metrics for overall performance in a multi-device environment. In our benchmark test, the GPU is found to produce the best arithmetic performance as a standalone device unit, and gives the most efficient power consumption. The multi-core CPU obtains the most effective computing performance. The computational speed of the MIC processor on Xeon Phi approached that of two Xeon CPUs. This indicates that using MICs is an attractive choice for existing SPH codes on multi-core CPUs parallelized by OpenMP, as it gains computational acceleration without the need for significant changes to the source code.

Sharing Data between Mobile Devices, Connected Vehicles and Infrastructure Task 8 : D2X Hub Proof-of-Concept Test Evaluation Report.

DOT National Transportation Integrated Search

2017-10-25

The Task 8 D2X Hub Proof-of-Concept Test Evaluation Report provides results of the experimental data analysis performed in accordance with the experimental plan for the proof-of-concept version of the prototype system. The data set analyzed includes ...

Regulating the economic evaluation of pharmaceuticals and medical devices: a European perspective.

PubMed

Cookson, Richard; Hutton, John

2003-02-01

Throughout the developed world, economic evaluation of costly new pharmaceuticals and medical devices became increasingly widespread and systematic during the 1990s. However, serious concerns remain about the validity and relevance of this economic evidence, and about the transparency and accountability of its use in public sector reimbursement decisions. In this article, we summarise current concerns in Europe, based on interviews with European health economists from industry, universities, research institutes and consulting firms. We identify five challenges for European policy-makers, and conclude that there is considerable scope for improving decision-making without damaging incentives to innovate. The challenges are: (1). full publication of the economic evidence used in reimbursement decisions; (2). the redesign of licensing laws to improve the relevance of economic data available at product launch; (3). harmonisation of economic evaluation methodologies; (4). development of methodologies for evaluation of health inequality impacts; and (5). negotiation of price-performance deals to facilitate the use of economic evidence in post-launch pricing review decisions, as information is gathered from studies of product performance in routine use.

Advancements in the Design and Fabrication of Ultrasound Transducers for Extreme Temperatures

NASA Astrophysics Data System (ADS)

Bosyj, Christopher

An ultrasound transducer for operation from room temperature to 800 °C is developed. The device includes a lithium niobate piezoelectric crystal, a porous zirconia attenuative backing layer, and a quarter wavelength matching layer. The manufacturing procedure for porous zirconia is optimized by adjusting pore size and forming pressure to yield good acoustic performance and mechanical integrity. Several acoustic coupling methods are evaluated. A novel silver-copper braze and an aluminum-based braze are found to be suitable at elevated temperatures. Several materials are evaluated for their performance as a quarter wavelength matching layer in the transducer stack. The use of either a nickel-chromium or stainless steel matching layer is established in place of ceramic components. Equipment limitations prevent evaluation at 800 °C, though ultrasound transmission is theoretically achievable with the devices established by this study. Reliable high-amplitude, wide-bandwidth ultrasound transmission is achieved from room temperature to 600 °C with two transducer variants.

Pan-nitinol occluder and special delivery device for closure of patent ductus arteriosus: a canine-model feasibility study.

PubMed

Jiang, Hai-bin; Bai, Yuan; Zong, Gang-jun; Han, Lin; Li, Wei-ping; Lu, Yang; Qin, Yong-wen; Zhao, Xian-xian

2013-01-01

The aim of this study was to evaluate a new type of occluder for patent ductus arteriosus. Patent ductus arteriosus was established in a canine model by anastomosing a length of autologous jugular vein to the descending aorta and the left pulmonary artery in an end-to-side fashion. Transcatheter closure of each patent ductus arteriosus was performed on 10 dogs, which were then monitored for as long as 6 months with aortography, echocardiography, and histologic evaluation. Transcatheter closure with use of the novel pan-nitinol device was successful in all canine models. Postoperative echocardiography showed that the location and shape of the occluders were normal, without any residual shunting. Further histologic evaluation confirmed that the occluder surface was completely endothelialized 3 months after implantation. Transcatheter patent ductus arteriosus closure with the pan-nitinol occluder can be performed safely and successfully in a canine model and shows good biological compatibility and low mortality rates.

Predicting successful tactile mapping of virtual objects.

PubMed

Brayda, Luca; Campus, Claudio; Gori, Monica

2013-01-01

Improving spatial ability of blind and visually impaired people is the main target of orientation and mobility (O&M) programs. In this study, we use a minimalistic mouse-shaped haptic device to show a new approach aimed at evaluating devices providing tactile representations of virtual objects. We consider psychophysical, behavioral, and subjective parameters to clarify under which circumstances mental representations of spaces (cognitive maps) can be efficiently constructed with touch by blindfolded sighted subjects. We study two complementary processes that determine map construction: low-level perception (in a passive stimulation task) and high-level information integration (in an active exploration task). We show that jointly considering a behavioral measure of information acquisition and a subjective measure of cognitive load can give an accurate prediction and a practical interpretation of mapping performance. Our simple TActile MOuse (TAMO) uses haptics to assess spatial ability: this may help individuals who are blind or visually impaired to be better evaluated by O&M practitioners or to evaluate their own performance.

Device and circuit analysis of a sub 20 nm double gate MOSFET with gate stack using a look-up-table-based approach

NASA Astrophysics Data System (ADS)

Chakraborty, S.; Dasgupta, A.; Das, R.; Kar, M.; Kundu, A.; Sarkar, C. K.

2017-12-01

In this paper, we explore the possibility of mapping devices designed in TCAD environment to its modeled version developed in cadence virtuoso environment using a look-up table (LUT) approach. Circuit simulation of newly designed devices in TCAD environment is a very slow and tedious process involving complex scripting. Hence, the LUT based modeling approach has been proposed as a faster and easier alternative in cadence environment. The LUTs are prepared by extracting data from the device characteristics obtained from device simulation in TCAD. A comparative study is shown between the TCAD simulation and the LUT-based alternative to showcase the accuracy of modeled devices. Finally the look-up table approach is used to evaluate the performance of circuits implemented using 14 nm nMOSFET.

A training paradigm to enhance performance and safe use of an innovative neuroendovascular device

PubMed Central

Ricci, Donald R.; Marotta, Thomas R.; Riina, Howard A.; Wan, Martina; De Vries, Joost

2016-01-01

Training has been important to facilitate the safe use of new devices designed to repair vascular structures. This paper outlines the generic elements of a training program for vascular devices and uses as an example the actual training requirements for a novel device developed for the treatment of bifurcation intracranial aneurysms. Critical elements of the program include awareness of the clinical problem, technical features of device, case selection, and use of a simulator. Formal proctoring, evaluation of the training, and recording the clinical outcomes complement these elements. Interventional physicians should embrace the merits of a training module to improve the user experience, and vendors, physicians, and patients alike should be aligned in the goal of device training to improve its success rate and minimize complications of the procedure. PMID:27867466

Method for nondestructive testing of the film coating behavior of surface acoustic wave (SAW) sensors

NASA Astrophysics Data System (ADS)

Taslakov, M. A.; Avramov, I. D.

2010-04-01

This paper presents a practical non-destructive method for studying the film coating behavior of SAW devices by using a water soluble dielectric film (manitol) deposited on the SAW device surface by resistive evaporation. After measuring the electrical parameters of the film coated SAW device, the film can easily be removed from its surface by water rinsing without causing any damage to it. The SAW device can then be used over and over again in a large number of film depositions. The method was tested on a 1 GHz surface transverse wave (STW) resonator coated with manitol of varying thickness. After each coating and evaluation, the STW device was successfully recovered without significant performance degradation. Data is presented on the electrical changes of the STW device as a result of depositing manitol coatings of various thicknesses.

Measuring the Impact of Cognitive Prosthetics on the Daily Life of People with Dementia and Their Carers

NASA Astrophysics Data System (ADS)

Meiland, Franka; Dröes, Rose-Marie; Sävenstedt, Stefan

Assistive technologies to support persons with dementia and their carers are used increasingly often. However, little is known about the effectiveness of most assistive devices. Much technology is put on the market without having been properly tested with potential end-users. To increase the chance that an assistive device is well accepted and useful for the target group, it is important, especially in the case of disabled persons, to involve potential users in the development process and to evaluate the impact of using the device on them before implementing it in the daily care and support. When evaluating the impact, decisions have to be made regarding the selection of measuring instruments. Important considerations in the selection process are the underlying domains to be addressed by the assistive technology, the target group and the availability of standardized instruments with good psychometric properties. In this chapter the COGKNOW project is used as a case example to explain how the impact of cognitive prosthetics on the daily lives of people with dementia and their carers can be measured. In COGKNOW a cognitive prosthetic device is being developed to improve the quality of life and autonomy of persons with dementia and to help them to remember and remind, to have social contact, to perform daily activities and to enhance feelings of safety. For all these areas, potential measuring instruments are described. Besides (standardized) measuring instruments, other data collection methods are used as well, such as semi-structured interviews and observations, diaries and in situ measurement. Within the COGKNOW project a first uncontrolled small-scale impact measurement takes place during the development process of the assistive device. However, it is recommended to perform a larger randomized controlled study as soon as the final product is ready to evaluate the impact of the device on persons with dementia and carers before it is released on the market.

Soft shape-adaptive gripping device made from artificial muscle

NASA Astrophysics Data System (ADS)

Hamburg, E.; Vunder, V.; Johanson, U.; Kaasik, F.; Aabloo, A.

2016-04-01

We report on a multifunctional four-finger gripper for soft robotics, suitable for performing delicate manipulation tasks. The gripping device is comprised of separately driven gripping and lifting mechanisms, both made from a separate single piece of smart material - ionic capacitive laminate (ICL) also known as artificial muscle. Compared to other similar devices the relatively high force output of the ICL material allows one to construct a device able to grab and lift objects exceeding multiple times its own weight. Due to flexible design of ICL grips, the device is able to adapt the complex shapes of different objects and allows grasping single or multiple objects simultaneously without damage. The performance of the gripper is evaluated in two different configurations: a) the ultimate grasping strength of the gripping hand; and b) the maximum lifting force of the lifting actuator. The ICL is composed of three main layers: a porous membrane consisting of non-ionic polymer poly(vinylidene fluoride-co-hexafluoropropene) (PVdF-HFP), ionic liquid 1-ethyl-3-methylimidazolium trifluoromethane-sulfonate (EMITFS), and a reinforcing layer of woven fiberglass cloth. Both sides of the membrane are coated with a carbonaceous electrode. The electrodes are additionally covered with thin gold layers, serving as current collectors. Device made of this material operates silently, requires low driving voltage (<3 V), and is suitable for performing tasks in open air environment.

Accuracy evaluation of five blood glucose monitoring systems obtained from the pharmacy: a European multicenter study with 453 subjects.

PubMed

Tack, Cornelius; Pohlmeier, Harald; Behnke, Thomas; Schmid, Volkmar; Grenningloh, Marco; Forst, Thomas; Pfützner, Andreas

2012-04-01

This multicenter study was conducted to evaluate the performance of five recently introduced blood glucose (BG) monitoring (BGM) devices under daily routine conditions in comparison with the YSI (Yellow Springs, OH) 2300 Stat Plus glucose analyzer. Five hundred one diabetes patients with experience in self-monitoring of BG were randomized to use three of five different BGM devices (FreeStyle Lite® [Abbott Diabetes Care Inc., Alameda, CA], FreeStyle Freedom Lite [Abbott Diabetes Care], OneTouch® UltraEasy® [LifeScan Inc., Milpitas, CA], Accu-Chek® Aviva [Roche Diagnostics, Mannheim, Germany], and Contour® [Bayer Vital GmbH, Leverkusen, Germany]) in a daily routine setting. All devices and strips were purchased from local regular distribution sources (pharmacies, four strip lots per device). The patients performed the finger prick and the glucose measurement on their own. In parallel, a healthcare professional performed the glucose assessment with the reference method (YSI 2300 Stat Plus). The primary objective was the comparison of the mean absolute relative differences (MARD). Secondary objectives were compliance with the International Organization for Standardization (ISO) accuracy criteria under these routine conditions and Clarke and Parkes Error Grid analyses. MARD ranged from 4.9% (FreeStyle Lite) to 9.7% (OneTouch UltraEasy). The ISO 15197:2003 requirements were fulfilled by the FreeStyle Lite (98.8%), FreeStyle Freedom Lite (97.5%), and Accu-Chek Aviva (97.0%), but not by the Contour (92.4%) and OneTouch UltraEasy (91.1%). The number of values in Zone A of the Clarke Error Grid analysis was highest for the FreeStyle Lite (98.8%) and lowest for the OneTouch Ultra Easy (90.4%). FreeStyle Lite, FreeStyle Freedom Lite, and Accu-Chek Aviva performed very well in this study with devices and strips purchased through regular distribution channels, with the FreeStyle Lite achieving the lowest MARD in this investigation.

Accuracy Evaluation of Five Blood Glucose Monitoring Systems Obtained from the Pharmacy: A European Multicenter Study with 453 Subjects

PubMed Central

Tack, Cornelius; Pohlmeier, Harald; Behnke, Thomas; Schmid, Volkmar; Grenningloh, Marco; Forst, Thomas

2012-01-01

Abstract Background This multicenter study was conducted to evaluate the performance of five recently introduced blood glucose (BG) monitoring (BGM) devices under daily routine conditions in comparison with the YSI (Yellow Springs, OH) 2300 Stat Plus glucose analyzer. Methods Five hundred one diabetes patients with experience in self-monitoring of BG were randomized to use three of five different BGM devices (FreeStyle Lite® [Abbott Diabetes Care Inc., Alameda, CA], FreeStyle Freedom Lite [Abbott Diabetes Care], OneTouch® UltraEasy® [LifeScan Inc., Milpitas, CA], Accu-Chek® Aviva [Roche Diagnostics, Mannheim, Germany], and Contour® [Bayer Vital GmbH, Leverkusen, Germany]) in a daily routine setting. All devices and strips were purchased from local regular distribution sources (pharmacies, four strip lots per device). The patients performed the finger prick and the glucose measurement on their own. In parallel, a healthcare professional performed the glucose assessment with the reference method (YSI 2300 Stat Plus). The primary objective was the comparison of the mean absolute relative differences (MARD). Secondary objectives were compliance with the International Organization for Standardization (ISO) accuracy criteria under these routine conditions and Clarke and Parkes Error Grid analyses. Results MARD ranged from 4.9% (FreeStyle Lite) to 9.7% (OneTouch UltraEasy). The ISO 15197:2003 requirements were fulfilled by the FreeStyle Lite (98.8%), FreeStyle Freedom Lite (97.5%), and Accu-Chek Aviva (97.0%), but not by the Contour (92.4%) and OneTouch UltraEasy (91.1%). The number of values in Zone A of the Clarke Error Grid analysis was highest for the FreeStyle Lite (98.8%) and lowest for the OneTouch Ultra Easy (90.4%). Conclusions FreeStyle Lite, FreeStyle Freedom Lite, and Accu-Chek Aviva performed very well in this study with devices and strips purchased through regular distribution channels, with the FreeStyle Lite achieving the lowest MARD in this investigation. PMID:22176154

How Accurately Can Your Wrist Device Recognize Daily Activities and Detect Falls?

PubMed Central

Gjoreski, Martin; Gjoreski, Hristijan; Luštrek, Mitja; Gams, Matjaž

2016-01-01

Although wearable accelerometers can successfully recognize activities and detect falls, their adoption in real life is low because users do not want to wear additional devices. A possible solution is an accelerometer inside a wrist device/smartwatch. However, wrist placement might perform poorly in terms of accuracy due to frequent random movements of the hand. In this paper we perform a thorough, large-scale evaluation of methods for activity recognition and fall detection on four datasets. On the first two we showed that the left wrist performs better compared to the dominant right one, and also better compared to the elbow and the chest, but worse compared to the ankle, knee and belt. On the third (Opportunity) dataset, our method outperformed the related work, indicating that our feature-preprocessing creates better input data. And finally, on a real-life unlabeled dataset the recognized activities captured the subject’s daily rhythm and activities. Our fall-detection method detected all of the fast falls and minimized the false positives, achieving 85% accuracy on the first dataset. Because the other datasets did not contain fall events, only false positives were evaluated, resulting in 9 for the second, 1 for the third and 15 for the real-life dataset (57 days data). PMID:27258282

International Conference on the Mechanical Technology of Inertial Devices, University of Newcastle-upon-Tyne, England, Apr. 7-9, 1987, Proceedings

NASA Astrophysics Data System (ADS)

Various papers on the mechanical technology of inertial devices are presented. The topics addressed include: development of a directional gyroscope for remotely piloted vehicles and similar applications; a two-degree-of-freedom gyroscope with frictionless inner and outer gimbal pickoffs; oscillogyro design, manufacture, and performance; development of miniature two-axis rate gyroscope; mechanical design aspects of the electrostatically suspended gyroscope; role of gas-lubricated bearings in current and future sensors; development of a new microporous retainer material for precision ball bearings; design study for a high-stability, large-centrifuge test bed; evaluation of a two-axis rate gyro; operating principles of a two-axis angular rate transducer; and nutation frequency analysis. Also considered are: triaxial laser gyro; mechanical design considerations for a ring laser gyro dither mechanism; environmental considerations in the design of fiberoptic gyroscopes; manufacturing aspects of some critical high-precision mechanical components of inertial devices; dynamics and control of a gyroscopic force measurement system; high precision and high performance motion systems; use of multiple acceleration references to obtain high precision centrifuge data at low cost; gyro testing and evaluation at the Communications Research Centre; review of the mechanical design and development of a high-performance accelerometer; and silicon microengineering for accelerometers.

Low-level light therapy for androgenetic alopecia: a 24-week, randomized, double-blind, sham device-controlled multicenter trial.

PubMed

Kim, Hyojin; Choi, Jee Woong; Kim, Jun Young; Shin, Jung Won; Lee, Seok-Jong; Huh, Chang-Hun

2013-08-01

Androgenetic alopecia (AGA) is a common disorder affecting men and women. Finasteride and minoxidil are well-known, effective treatment methods, but patients who exhibit a poor response to these methods have no additional adequate treatment modalities. To evaluate the efficacy and safety of a low-level light therapy (LLLT) device for the treatment of AGA. This study was designed as a 24-week, randomized, double-blind, sham device-controlled trial. Forty subjects with AGA were enrolled and scheduled to receive treatment with a helmet-type, home-use LLLT device emitting wavelengths of 630, 650, and 660 nm or a sham device for 18 minutes daily. Investigator and subject performed phototrichogram assessment (hair density and thickness) and global assessment of hair regrowth for evaluation. After 24 weeks of treatment, the LLLT group showed significantly greater hair density than the sham device group. Mean hair diameter improved statistically significantly more in the LLLT group than in the sham device group. Investigator global assessment showed a significant difference between the two groups, but that of the subject did not. No serious adverse reactions were detected. LLLT could be an effective treatment for AGA. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Breathing simulator of workers for respirator performance test.

PubMed

Yuasa, Hisashi; Kumita, Mikio; Honda, Takeshi; Kimura, Kazushi; Nozaki, Kosuke; Emi, Hitoshi; Otani, Yoshio

2015-01-01

Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker's respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.

Layout optimization of GGISCR structure for on-chip system level ESD protection applications

NASA Astrophysics Data System (ADS)

Zeng, Jie; Dong, Shurong; Wong, Hei; Hu, Tao; Li, Xiang

2016-12-01

To improve the holding voltage, area efficiency and robustness, a comparative study on single finger, 4-finger and round shape layout of gate-grounded-nMOS incorporated SCR (GGISCR) devices are conducted. The devices were fabricated with a commercial 0.35 μm HV-CMOS process without any additional mask or process modification. To have a fair comparison, we develop a new Figure-of-Merit (FOM) modeling for the performance evaluation of these devices. We found that the ring type device which has an It2 value of 18.9 A is area efficient and has smaller effective capacitance. The different characteristics were explained with the different effective ESD currents in these layout structures.

Magnetic Surgery

PubMed Central

Rivas, Homero; Robles, Ignacio; Riquelme, Francisco; Vivanco, Marcelo; Jiménez, Julio; Marinkovic, Boris; Uribe, Mario

2018-01-01

Objective: To evaluate a new magnetic surgical system during reduced-port laparoscopic cholecystectomy in a prospective, multicenter clinical trial. Background: Laparoscopic instrumentation coupled by magnetic fields may enhance surgeon performance by allowing for shaft-less retraction and mobilization. The movements can be performed under direct visualization, generating different angles of traction and reducing the number of trocars to perform the procedure. This may reduce well-known associated complications of trocars, including incisional pain, scarring, infection, bowel, and vascular injuries, among others. Methods: A prospective, multicenter, single-arm, open-label study was performed to assess the safety and performance of a magnetic surgical system (Levita Magnetics’ Surgical System). The investigational device was used during a 3-port laparoscopic technique. The primary endpoints evaluated were safety and feasibility of the device to adequately mobilize the gallbladder to achieve effective exposure of the targeted surgical site. Patients were followed for 30 days postprocedure. Results: Between January 2014 and March 2015, 50 patients presenting with benign gallbladder disease were recruited. Forty-five women and 5 men with an average age of 39 years (18–59), average body mass index of 27 kg/m2 (20.4–34.1) and an average abdominal wall thickness of 2.6 cm (1.8–4.6). The procedures were successfully performed in all 50 patients. No device-related serious adverse events were reported. Surgeons rated as “excellent” (90%) or “sufficient” (10%) the exposure of the surgical site. Conclusions: This clinical trial shows that this new magnetic surgical system is safe and effective in reduced-port laparoscopic cholecystectomy. PMID:27759614

Evaluation of a device for standardized measurements of reading performance in a prepresbyopic population.

PubMed

Arad, Tschingis; Baumeister, Martin; Bühren, Jens; Kohnen, Thomas

2017-04-20

Automated measurements of reading performance are required for clinical trials involving presbyopia-correcting surgery options. Repeatability of a testing device for reading (Salzburg Reading Desk) was evaluated in a prepresbyopic population. Subjective reading performance of 50 subjects divided into 2 age groups (23-30 years and 38-49 years) with distance-corrected eyes was investigated with different log-scaled reading charts. At study entry, refractive parameters were measured and distance visual acuity assessed. Two standardized binocular measurements were performed for each subject (32.24 ± 9.87 days apart [mean ± SD]). The repeatability of the tests was estimated using correlation coefficients, Wilcoxon signed-rank test, and Bland-Altman method. The test parameters at both maximum reading rate (MRR) measurements demonstrate a strong relationship of age group 2 subjects (correlation coefficient [r] = 0.74 p = 10-4) and of younger subjects (age group 1: r = 0.69, p = 10-4). Prepresbyopic subjects of age group 2 showed moderate results for near reading distance (r = 0.67, p = 10-4); by contrast, younger subjects had poorer results (r = 0.55, p = 10-3). The Wilcoxon signed-rank test revealed agreement between measurements and Bland-Altman plots showed a wide data spread for MRR and near reading distance in both groups. The device measures repeatedly selected reading performance parameters of near real world conditions, such as MRR, in prepresbyopic populations if several factors are taken into account. The option to choose preferred distance leads to more variance in measuring repeated reading performance. German Clinical Trials Register (DRKS) registration reference number: DRKS00000784.

Verification of a novel point-of-care HbA1c device in real world clinical practice by comparison to three high performance liquid chromatography instruments.

PubMed

Wang, Yufei; Peng, Wei; Tang, Junling; Dong, Lu; Gu, Chengchen; Zhang, Xin; Zhou, Jian; Jia, Weiping

2018-06-15

A real world clinical study was designed and conducted to evaluate the performance of a novel point-of-care device for determination of glycated haemoglobin A 1c (HbA 1c ), A1C EZ 2.0, in daily clinical practice. Five hundred and fourteen subjects were included in this study, and divided into three groups. HbA 1c was measured by A1C EZ 2.0 and three different high performance liquid chromatography (HPLC) devices: Bio-Rad Variant II Turbo, Tosoh HLC-723 G8 and Premier Hb9210 separately. Precision of A1C EZ 2.0 was also evaluated. Results obtained from A1C EZ 2.0 and all HPLC devices are correlated. Passing-Bablok regression analysis shows the equation of A1C EZ 2.0 results against the mean of HPLC devices with corresponding 95% confidence intervals (95% CI) for the intercept and slope is y = 0.10 (- 0.17 to 0.10) + 1.00 (1.00 to 1.04) x. Bland-Altman difference plot shows that the mean relative difference between A1C EZ 2.0 and Variant II Turbo, G8, Hb9210 and all HPLC results is 2.5%, 0.6%, 0.4% and 1.1%, respectively. In addition, 121 pairs of results determined by using both venous and capillary blood prove that the difference of two kinds of blood sample causes no notable variation when measured by A1C EZ 2.0. Precision study gives 2.3% and 1.9% of total coefficient of variation for normal and abnormal HbA 1c sample in A1C EZ 2.0. HbA 1c values measured by A1C EZ 2.0 were in good accordance with the results obtained with the reference HPLC devices.

77 FR 75173 - Comprehensive Assessment of the Process for the Review of Device Submissions; Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-19

... performing the technical analysis, management assessment, and program evaluation tasks required to address... premarket reviews that meet regulatory review standards. 2. Analysis of elements of the review process... process. This includes analysis of root causes for inefficiencies that may affect review performance and...

40 CFR 63.1312 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

....111) Owner or operator (§ 63.2) Performance evaluation (§ 63.2) Performance test (§ 63.2) Permitting...-up, shutdown, and malfunction plan (§ 63.101) State (§ 63.2) Stationary Source (§ 63.2) Surge control vessel (§ 63.161) Temperature monitoring device (§ 63.111) Test method (§ 63.2) Treatment process (§ 63...

40 CFR 63.1312 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1312 Definitions. (a) The... (§ 63.111) Owner or operator (§ 63.2) Performance evaluation (§ 63.2) Performance test (§ 63.2... gravity monitoring device (§ 63.111) State (§ 63.2) Stationary Source (§ 63.2) Surge control vessel (§ 63...

Use of Portable Digital Devices to Analyze Autonomic Stress Response in Psychology Objective Structured Clinical Examination.

PubMed

Beltrán-Velasco, Ana Isabel; Bellido-Esteban, Alberto; Ruisoto-Palomera, Pablo; Clemente-Suárez, Vicente Javier

2018-01-12

The aim of the present study was to explore changes in the autonomic stress response of Psychology students in a Psychology Objective Structured Clinical Examination (OSCE) and their relationship with OSCE performance. Variables of autonomic modulation by the analysis of heart rate variability in temporal, frequency and non-linear domains, subjective perception of distress strait and academic performance were measured before and after the two different evaluations that composed the OSCE. A psychology objective structured clinical examination composed by two different evaluation scenarios produced a large anxiety anticipatory response, a habituation response in the first of the evaluation scenarios and a in the entire evaluation, and a no habituation response in the second evaluation scenario. Autonomic modulation parameters do not correlate with academic performance of students.

Design and Evaluation of Shape-Changing Haptic Interfaces for Pedestrian Navigation Assistance.

PubMed

Spiers, Adam J; Dollar, Aaron M

2017-01-01

Shape-changing interfaces are a category of device capable of altering their form in order to facilitate communication of information. In this work, we present a shape-changing device that has been designed for navigation assistance. 'The Animotus' (previously, 'The Haptic Sandwich' ), resembles a cube with an articulated upper half that is able to rotate and extend (translate) relative to the bottom half, which is fixed in the user's grasp. This rotation and extension, generally felt via the user's fingers, is used to represent heading and proximity to navigational targets. The device is intended to provide an alternative to screen or audio based interfaces for visually impaired, hearing impaired, deafblind, and sighted pedestrians. The motivation and design of the haptic device is presented, followed by the results of a navigation experiment that aimed to determine the role of each device DOF, in terms of facilitating guidance. An additional device, 'The Haptic Taco', which modulated its volume in response to target proximity (negating directional feedback), was also compared. Results indicate that while the heading (rotational) DOF benefited motion efficiency, the proximity (translational) DOF benefited velocity. Combination of the two DOF improved overall performance. The volumetric Taco performed comparably to the Animotus' extension DOF.

Evaluation of an investigational wearable injector in healthy human volunteers.

PubMed

Torjman, Marc C; Machnicki, Robert; Lessin, Jennifer; Loeum, Channy; Steinberger, Douglas; Mycroft, Sarah; Joseph, Jeffrey I

2017-01-01

Introduction of a wearable device for subcutaneous delivery of larger volume bolus injections would encourage patient compliance and reduce the burden on healthcare services. With one such wearable device commercially available, this study examined the safety and functionality of an investigational device in volunteers. Four devices were applied to the subject's abdomen: 1) Investigational Device, 2) Investigational Device: subject movement, 3) Control Device: FDA-cleared syringe driver with FDA-cleared infusion set, 4) Control Device: FDA-cleared syringe driver attached to investigational device. Three milliliters of saline were infused through the four devices over 3 minutes. 84 devices were applied to 21 subjects. Three milliliters of saline were safely delivered subcutaneously from the investigational and control devices. Two control devices had occlusions and in each case the pump reached its high pressure limit of 12 psi. VAS pain measurements showed minimal pain for all subjects. Pain scores were significantly (p < 0.001) higher than baseline at the end of injection: mean pain level ranged from 2.0-22.0 mm. The investigational device performed as intended with minimal pain during needle insertion and infusion, and no leaking of fluid at the skin puncture site. Two occlusions occurred with the control devices.

A PDMS Device Coupled with Culture Dish for In Vitro Cell Migration Assay.

PubMed

Lv, Xiaoqing; Geng, Zhaoxin; Fan, Zhiyuan; Wang, Shicai; Pei, WeiHua; Chen, Hongda

2018-04-30

Cell migration and invasion are important factors during tumor progression and metastasis. Wound-healing assay and the Boyden chamber assay are efficient tools to investigate tumor development because both of them could be applied to measure cell migration rate. Therefore, a simple and integrated polydimethylsiloxane (PDMS) device was developed for cell migration assay, which could perform quantitative evaluation of cell migration behaviors, especially for the wound-healing assay. The integrated device was composed of three units, which included cell culture dish, PDMS chamber, and wound generation mold. The PDMS chamber was integrated with cell culture chamber and could perform six experiments under different conditions of stimuli simultaneously. To verify the function of this device, it was utilized to explore the tumor cell migration behaviors under different concentrations of fetal bovine serum (FBS) and transforming growth factor (TGF-β) at different time points. This device has the unique capability to create the "wound" area in parallel during cell migration assay and provides a simple and efficient platform for investigating cell migration assay in biomedical application.

A piezo-ring-on-chip microfluidic device for simple and low-cost mass spectrometry interfacing.

PubMed

Tsao, Chia-Wen; Lei, I-Chao; Chen, Pi-Yu; Yang, Yu-Liang

2018-02-12

Mass spectrometry (MS) interfacing technology provides the means for incorporating microfluidic processing with post MS analysis. In this study, we propose a simple piezo-ring-on-chip microfluidic device for the controlled spraying of MALDI-MS targets. This device uses a low-cost, commercially-available ring-shaped piezoelectric acoustic atomizer (piezo-ring) directly integrated into a polydimethylsiloxane microfluidic device to spray the sample onto the MS target substrate. The piezo-ring-on-chip microfluidic device's design, fabrication, and actuation, and its pulsatile pumping effects were evaluated. The spraying performance was examined by depositing organic matrix samples onto the MS target substrate by using both an automatic linear motion motor, and manual deposition. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was performed to analyze the peptide samples on the MALDI target substrates. Using our technique, model peptides with 10 -6 M concentration can be successfully detected. The results also indicate that the piezo-ring-on-chip approach forms finer matrix crystals and presents better MS signal uniformity with little sample consumption compared to the conventional pipetting method.

Percutaneous Endovascular Salvage Techniques for Implanted Venous Access Device Dysfunction

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

Breault, Stéphane, E-mail: stephane.breault@chuv.ch; Glauser, Frédéric, E-mail: frederic.glauser@chuv.ch; Babaker, Malik, E-mail: malik.babaker@chuv.ch

2015-06-15

PurposeImplanted venous access devices (IVADs) are often used in patients who require long-term intravenous drug administration. The most common causes of device dysfunction include occlusion by fibrin sheath and/or catheter adherence to the vessel wall. We present percutaneous endovascular salvage techniques to restore function in occluded catheters. The aim of this study was to evaluate the feasibility, safety, and efficacy of these techniques.Methods and MaterialsThrough a femoral or brachial venous access, a snare is used to remove fibrin sheath around the IVAD catheter tip. If device dysfunction is caused by catheter adherences to the vessel wall, a new “mechanical adhesiolysis”more » maneuver was performed. IVAD salvage procedures performed between 2005 and 2013 were analyzed. Data included clinical background, catheter tip position, success rate, recurrence, and rate of complication.ResultsEighty-eight salvage procedures were performed in 80 patients, mostly women (52.5 %), with a mean age of 54 years. Only a minority (17.5 %) of evaluated catheters were located at an optimal position (i.e., cavoatrial junction ±1 cm). Mechanical adhesiolysis or other additional maneuvers were used in 21 cases (24 %). Overall technical success rate was 93.2 %. Malposition and/or vessel wall adherences were the main cause of technical failure. No complications were noted.ConclusionThese IVAD salvage techniques are safe and efficient. When a catheter is adherent to the vessel wall, mechanical adhesiolysis maneuvers allow catheter mobilization and a greater success rate with no additional risk. In patients who still require long-term use of their IVAD, these procedures can be performed safely to avoid catheter replacement.« less

PROSPECTIVE EVALUATION OF VISUAL ACUITY AGREEMENT BETWEEN STANDARD EARLY TREATMENT DIABETIC RETINOPATHY STUDY CHART AND A HANDHELD EQUIVALENT IN EYES WITH RETINAL PATHOLOGY.

PubMed

Rahimy, Ehsan; Reddy, Sahitya; DeCroos, Francis Char; Khan, M Ali; Boyer, David S; Gupta, Omesh P; Regillo, Carl D; Haller, Julia A

2015-08-01

To evaluate the visual acuity agreement between a standard back-illuminated Early Treatment Diabetic Retinopathy Study (ETDRS) chart and a handheld internally illuminated ETDRS chart. Two-center prospective study. Seventy patients (134 eyes) with retinal pathology were enrolled between October 2012 and August 2013. Visual acuity was measured using both the ETDRS chart and the handheld device by masked independent examiners after best protocol refraction. Examination was performed in the same room under identical illumination and testing conditions. The mean number of letters seen was 63.0 (standard deviation: 19.8 letters) and 61.2 letters (standard deviation: 19.1 letters) for the ETDRS chart and handheld device, respectively. Mean difference per eye between the ETDRS and handheld device was 1.8 letters. A correlation coefficient (r) of 0.95 demonstrated a positive linear correlation between ETDRS chart and handheld device measured acuities. Intraclass correlation coefficient was performed to assess the reproducibility of the measurements made by different observers measuring the same quantity and was calculated to be 0.95 (95% confidence interval: 0.93-0.96). Agreement was independent of retinal disease. The strong correlation between measured visual acuity using the ETDRS and handheld equivalent suggests that they may be used interchangeably, with accurate measurements. Potential benefits of this device include convenience and portability, as well as the ability to assess ETDRS visual acuity without a dedicated testing lane.

Parallel affinity-based isolation of leukocyte subsets using microfluidics: application for stroke diagnosis.

PubMed

Pullagurla, Swathi R; Witek, Małgorzata A; Jackson, Joshua M; Lindell, Maria A M; Hupert, Mateusz L; Nesterova, Irina V; Baird, Alison E; Soper, Steven A

2014-04-15

We report the design and performance of a polymer microfluidic device that can affinity select multiple types of biological cells simultaneously with sufficient recovery and purity to allow for the expression profiling of mRNA isolated from these cells. The microfluidic device consisted of four independent selection beds with curvilinear channels that were 25 μm wide and 80 μm deep and were modified with antibodies targeting antigens specifically expressed by two different cell types. Bifurcated and Z-configured device geometries were evaluated for cell selection. As an example of the performance of these devices, CD4+ T-cells and neutrophils were selected from whole blood as these cells are known to express genes found in stroke-related expression profiles that can be used for the diagnosis of this disease. CD4+ T-cells and neutrophils were simultaneously isolated with purities >90% using affinity-based capture in cyclic olefin copolymer (COC) devices with a processing time of ∼3 min. In addition, sufficient quantities of the cells could be recovered from a 50 μL whole blood input to allow for reverse transcription-polymerase chain reaction (RT-PCR) following cell lysis. The expression of genes from isolated T-cells and neutrophils, such as S100A9, TCRB, and FPR1, was evaluated using RT-PCR. The modification and isolation procedures demonstrated here can also be used to analyze other cell types as well where multiple subsets must be interrogated.

Evaluation of an Automated Reader and Color Interpretation-Based Immunoassays for Multiplexed Drug-of-Abuse Testing in Urine.

PubMed

Kim, Seon Young; Kim, Hyunjin; Park, Yeongchun; Lim, Jinsook; Kim, Jimyung; Koo, Sun Hoe; Kwon, Gye Cheol

2017-06-01

On-site drugs of abuse testing devices have undergone continuous improvement. We evaluated three devices with different designs: an automated reader, the Multi-Drug Screen Test Device with DxLINK (DxLINK; Innovacon, Alere, San Diego, USA) and two colorimetric immunoassays, the One Step Multi-Line Screen Panel with Integrated E-Z Split Key Cup II (E-Z Cup; Innovacon, Alere) and the One Step Multi-Drug Screen Panel card (Multi4 card; Alere, Abon Biopharm, Hangzhou, China). Eleven drugs [amphetamine, secobarbital, oxazepam, buprenorphine, benzoylecgonine, methylenedioxymethamphetamine (MDMA), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC), methamphetamine, methadone, morphine and nortriptyline] were tested using the DxLINK and E-Z Cup. Four drugs (benzoylecgonine, THC, methamphetamine and morphine) were tested using the Multi4 card using control materials (Detectabuse Stat-Skreen; Biochemical Diagnostics, Edgewood, NY, USA). The concentrations (-50%, -25%, +25%, +50% and 3× cut-off values) of the control materials were confirmed by mass spectrometry. Concordance rates were calculated around cut-offs. All devices showed high overall agreement rates of >90% with a few exceptions: the DxLINK exhibited lower sensitivity for benzoylecgonine, methadone and nortriptyline (60% and 30%, 92% and 40%, and 96% and 60% sensitivity at +50% and +25% cut-off levels, respectively). The E-Z Cup exhibited lower sensitivity for oxazepam and nortriptyline (97% and 50%, and 97% and 40% sensitivity at +50% and +25% cut-off levels, respectively). We additionally evaluated test-band color by visual inspection using a standard color-scale card. When detailed color criteria for determination of positivity were applied for the E-Z Cup, using slightly less stringent criteria, oxazepam, buprenorphine, MDMA and nortriptyline showed increases in sensitivity from 70-80% to 90-100%, all with a specificity above 98%. Overall, all devices exhibited satisfactory performance at ±50% cut-off levels for commonly used drugs, with the exception of lower sensitivity for cocaine testing for DxLINK. Careful evaluation of devices and elaborate calibration of visual interpretation for determining positivity may help improve the performance of these devices. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Noninvasive Assessment of Left Ventricular Assist Devices with Cardiovascular Computed Tomography and Impact on Management

PubMed Central

Raman, Subha V.; Sahu, Anurag; Merchant, Ali Z.; Louis, Louis B.; Firstenberg, Michael S.; Sun, Benjamin

2009-01-01

Background Left ventricular assist devices (LVADs) provide a bridge to recovery or heart transplantation, but require serial assessment. Echocardiographic approaches may be limited by device artifact and acoustic window. Cardiovascular computed tomography (CCT) provides noninvasive imaging of LVADs, yet no study has evaluated CCT’s impact on clinical care. We evaluated the diagnostic findings and clinical impact of CCT for noninvasive assessment of patients with LVADs. Methods CCT examinations performed between 2005 and 2008 in patients with LVADs were identified. Acquisitions were completed on the identical 64 detector-row scanner with intravenous contrast administration; electrocardiographic gating was used in patients with pulsatile devices, while peripheral pulse gating was used in patients with continuous-flow devices. Comparison was made between CCT results and 30-day outcomes, including echocardiographic and intraoperative findings. Results Thirty-two CCT examinations from 28 patients were reviewed. Indications included evaluation of low cardiac output symptoms, assessment of cannula position, low flow reading on the LVAD, and surgical planning. CCT identified critical findings in 6 patients including thrombosis and inlet cannula malposition, all confirmed intraoperatively; one case of intra-LVAD thrombus was missed by CCT. Using intraoperative findings as the gold standard, CCT’s sensitivity was 85% and specificity was 100%. Echocardiographic LVAD evaluation did not correlate with findings on CCT (kappa = −0.29, 95% CI −0.73−0.13). Conclusions This preliminary observational cohort study indicates that noninvasive imaging using CCT of LVADs is feasible and accurate. CCT warrants consideration in the initial evaluation of symptomatic patients with LVADs. PMID:19782594

FIELD DEMONSTRATION AND QUALITY ASSURANCE ...

EPA Pesticide Factsheets

The Demonstration of innovative field devices for the measurement of mercury in soil and sediment is being conducted under the EPA's SITE Program in February 2003 at the United States Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee and the Tennessee Department of Environment and Conservation's Department of Energy Oversight facility in Oak Ridge, Tennessee. The primary purpose of the Demonstration is to evaluate innovative field devices for the measurement of mercury in soil and sediment based on their performance and cost as compared to a conventional, off-site laboratory analytical method. The five field measurement devices listed below will be demonstrated: .Metorex's X-M ET 2000 Metal Master Analyzer, X-Ray Fluorescence Analyzer .Milestone Inc.'s Direct Mercury Analyzer (DMA-80), Thermal Decomposition Instrument.NITON's XL-700 Series Multi-Element Analyzer, X-Ray Fluorescence Analyzer .Ohio Lumex's RA-915+ Portable Mercury Analyzer, Atomic Absorption Spectrometer, Thermal Decompostion Attachment RP 91C .MTI, Inc.'s PDV 5000 Hand Held Instrument, Anodic Stripping Voltamm eter<1). This Demonstration Plan describes the procedures that will be used to verify the performance and cost of each field measurement device. The plan incorporates the quality assurance and quality control elements needed to generate data of sufficient quality to document each device's performance and cost. A separate Innovative Technology Verifica

Characterization of crosstalk in stereoscopic display devices.

PubMed

Zafar, Fahad; Badano, Aldo

2014-12-01

Many different types of stereoscopic display devices are used for commercial and research applications. Stereoscopic displays offer the potential to improve performance in detection tasks for medical imaging diagnostic systems. Due to the variety of stereoscopic display technologies, it remains unclear how these compare with each other for detection and estimation tasks. Different stereo devices have different performance trade-offs due to their display characteristics. Among them, crosstalk is known to affect observer perception of 3D content and might affect detection performance. We measured and report the detailed luminance output and crosstalk characteristics for three different types of stereoscopic display devices. We recorded the effect of other issues on recorded luminance profiles such as viewing angle, use of different eye wear, and screen location. Our results show that the crosstalk signature for viewing 3D content can vary considerably when using different types of 3D glasses for active stereo displays. We also show that significant differences are present in crosstalk signatures when varying the viewing angle from 0 degrees to 20 degrees for a stereo mirror 3D display device. Our detailed characterization can help emulate the effect of crosstalk in conducting computational observer image quality assessment evaluations that minimize costly and time-consuming human reader studies.

Effects and effectiveness of dynamic arm supports: a technical review.

PubMed

van der Heide, Loek A; Gelderblom, Gert Jan; de Witte, Luc P

2015-01-01

Numerous dynamic arm supports have been developed in recent decades to increase independence in the performance of activities of daily living. Much effort and money have been spent on their development and prescription, yet insight into their effects and effectiveness is lacking. This article is a systematic review of evaluations of dynamic arm supports. The 8 technical evaluations, 12 usability evaluations, and 27 outcome studies together make 47 evaluations. Technical evaluations were often used as input for new developments and directed at balancing quality, forces and torques, and range of motion of prototypes. Usability studies were mostly single-measure designs that had varying results as to whether devices were usable for potential users. An increased ability to perform activities of daily living and user satisfaction were reported in outcome studies. However, the use of dynamic arm supports in the home situation was reported to be low. Gaining insight into why devices are not used when their developers believe them to be effective seems crucial for every new dynamic arm support developed. The methodological quality of the outcome studies was often low, so it is important that this is improved in the future.

The ABCs of the FDA: A Primer on the Role of the United States Food and Drug Administration in Medical Device Approvals and IR Research.

PubMed

Adamovich, Ashley; Park, Susie; Siskin, Gary P; Englander, Meridith J; Mandato, Kenneth D; Herr, Allen; Keating, Lawrence J

2015-09-01

The role of the US Food and Drug Administration (FDA) in medical device regulation is important to device-driven specialties such as interventional radiology. Whether it is through industry-sponsored trials during the approval process for new devices or investigator-initiated research prospectively evaluating the role of existing devices for new or established procedures, interaction with the FDA is an integral part of performing significant research in interventional radiology. This article reviews the potential areas of interface between the FDA and interventional radiology, as understanding these areas is necessary to continue the innovation that is the hallmark of this specialty. Copyright © 2015 SIR. Published by Elsevier Inc. All rights reserved.

Aerodynamic drag reduction tests on a full-scale tractor-trailer combination with several add-on devices

NASA Technical Reports Server (NTRS)

Montoya, L. C.; Steers, L. L.

1974-01-01

Aerodynamic drag tests were performed on a conventional cab-over-engine tractor with a 45-foot trailer and five commercially available or potentially available add-on devices using the coast-down method. The tests ranged in velocity from approximately 30 miles per hour to 65 miles per hour and included some flow visualization. A smooth, level runway at Edwards Air Force Base was used for the tests, and deceleration measurements were taken with both accelerometers and stopwatches. An evaluation of the drag reduction results obtained with each of the five add-on devices is presented.

Blister pouches for effective reagent storage and release for low cost point-of-care diagnostic applications

NASA Astrophysics Data System (ADS)

Smith, Suzanne; Sewart, Rene; Land, Kevin; Roux, Pieter; Gärtner, Claudia; Becker, Holger

2016-03-01

Lab-on-a-chip devices are often applied to point-of-care diagnostic solutions as they are low-cost, compact, disposable, and require only small sample volumes. For such devices, various reagents are required for sample preparation and analysis and, for an integrated solution to be realized, on-chip reagent storage and automated introduction are required. This work describes the implementation and characterization of effective liquid reagent storage and release mechanisms utilizing blister pouches applied to various point-of-care diagnostic device applications. The manufacturing aspects as well as performance parameters are evaluated.

Evaluation of an automated ultraviolet-C light disinfection device and patient hand hygiene for reduction of pathogen transfer from interactive touchscreen computer kiosks.

PubMed

Alhmidi, Heba; Cadnum, Jennifer L; Piedrahita, Christina T; John, Amrita R; Donskey, Curtis J

2018-04-01

Touchscreens are a potential source of pathogen transmission. In our facility, patients and visitors rarely perform hand hygiene after using interactive touchscreen computer kiosks. An automated ultraviolet-C touchscreen disinfection device was effective in reducing bacteriophage MS2, bacteriophage ϕX174, methicillin-resistant Staphylococcus aureus, and Clostridium difficile spores inoculated onto a touchscreen. In simulations, an automated ultraviolet-C touchscreen disinfection device alone or in combination with hand hygiene reduced transfer of the viruses from contaminated touchscreens to fingertips. Published by Elsevier Inc.

Tilted pillar array fabrication by the combination of proton beam writing and soft lithography for microfluidic cell capture Part 2: Image sequence analysis based evaluation and biological application.

PubMed

Járvás, Gábor; Varga, Tamás; Szigeti, Márton; Hajba, László; Fürjes, Péter; Rajta, István; Guttman, András

2018-02-01

As a continuation of our previously published work, this paper presents a detailed evaluation of a microfabricated cell capture device utilizing a doubly tilted micropillar array. The device was fabricated using a novel hybrid technology based on the combination of proton beam writing and conventional lithography techniques. Tilted pillars offer unique flow characteristics and support enhanced fluidic interaction for improved immunoaffinity based cell capture. The performance of the microdevice was evaluated by an image sequence analysis based in-house developed single-cell tracking system. Individual cell tracking allowed in-depth analysis of the cell-chip surface interaction mechanism from hydrodynamic point of view. Simulation results were validated by using the hybrid device and the optimized surface functionalization procedure. Finally, the cell capture capability of this new generation microdevice was demonstrated by efficiently arresting cells from a HT29 cell-line suspension. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Milking performance evaluation and factors affecting milking claw vacuum levels with flow simulator.

PubMed

Enokidani, Masafumi; Kawai, Kazuhiro; Shinozuka, Yasunori; Watanabe, Aiko

2017-08-01

Milking performance of milking machines that matches the production capability of dairy cows is important in reducing the risk of mastitis, particularly in high-producing cows. This study used a simulated milking device to examine the milking performance of the milking system of 73 dairy farms and to analyze the factors affecting claw vacuum. Mean claw vacuum and range of fluctuation of claw vacuum (claw vacuum range) were measured at three different flow rates: 5.7, 7.6 and 8.7 kg/min. At the highest flow rate, only 16 farms (21.9%) met both standards of mean claw vacuum ≥35 kPa and claw vacuum range ≤ 7 kPa, showing that milking systems currently have poor milking performance. The factors affecting mean claw vacuum were claw type, milk-meter and vacuum shut-off device; the factor affecting claw vacuum range was claw type. Examination of the milking performance of the milking system using a simulated milking device allows an examination of the performance that can cope with high producing cows, indicating the possibility of reducing the risk of mastitis caused by inappropriate claw vacuum. © 2016 Japanese Society of Animal Science.

Analysis of latency performance of bluetooth low energy (BLE) networks.

PubMed

Cho, Keuchul; Park, Woojin; Hong, Moonki; Park, Gisu; Cho, Wooseong; Seo, Jihoon; Han, Kijun

2014-12-23

Bluetooth Low Energy (BLE) is a short-range wireless communication technology aiming at low-cost and low-power communication. The performance evaluation of classical Bluetooth device discovery have been intensively studied using analytical modeling and simulative methods, but these techniques are not applicable to BLE, since BLE has a fundamental change in the design of the discovery mechanism, including the usage of three advertising channels. Recently, there several works have analyzed the topic of BLE device discovery, but these studies are still far from thorough. It is thus necessary to develop a new, accurate model for the BLE discovery process. In particular, the wide range settings of the parameters introduce lots of potential for BLE devices to customize their discovery performance. This motivates our study of modeling the BLE discovery process and performing intensive simulation. This paper is focused on building an analytical model to investigate the discovery probability, as well as the expected discovery latency, which are then validated via extensive experiments. Our analysis considers both continuous and discontinuous scanning modes. We analyze the sensitivity of these performance metrics to parameter settings to quantitatively examine to what extent parameters influence the performance metric of the discovery processes.

Analysis of Latency Performance of Bluetooth Low Energy (BLE) Networks

PubMed Central

Cho, Keuchul; Park, Woojin; Hong, Moonki; Park, Gisu; Cho, Wooseong; Seo, Jihoon; Han, Kijun

2015-01-01

Bluetooth Low Energy (BLE) is a short-range wireless communication technology aiming at low-cost and low-power communication. The performance evaluation of classical Bluetooth device discovery have been intensively studied using analytical modeling and simulative methods, but these techniques are not applicable to BLE, since BLE has a fundamental change in the design of the discovery mechanism, including the usage of three advertising channels. Recently, there several works have analyzed the topic of BLE device discovery, but these studies are still far from thorough. It is thus necessary to develop a new, accurate model for the BLE discovery process. In particular, the wide range settings of the parameters introduce lots of potential for BLE devices to customize their discovery performance. This motivates our study of modeling the BLE discovery process and performing intensive simulation. This paper is focused on building an analytical model to investigate the discovery probability, as well as the expected discovery latency, which are then validated via extensive experiments. Our analysis considers both continuous and discontinuous scanning modes. We analyze the sensitivity of these performance metrics to parameter settings to quantitatively examine to what extent parameters influence the performance metric of the discovery processes. PMID:25545266

An Analytical and Experimental Analysis of Factors Affecting Exhaust System Performance in Sea Level Static Jet Engine Test Facilities.

DTIC Science & Technology

1972-12-01

include filtering devices, venturi scrubbers , and electrostatic precipitators. These have been evaluated as unsatisfactory from considerations of...Early studies of pollution abatement systems have resulted in the selection and development of a nucleation scrubber [Ref. 47]. Other devices analyzed...the venturi system is its inability to operate efficiently over greater than a 10 percent interval away from its design point, which is an

Research Issues in Training Device Design: The Organization of a Data Base

DTIC Science & Technology

1983-09-01

field. In many ways the automated system would enable the trainer to become more of a researcher , being in direct and immediate control of continuing...no control group is used and the assumption is that the final measure (on the new training device) is equivalent to the performance proficiency that...December 1978. 47 Evaluation of training: Subcommittee on Non -Atomic Military Research and Development. Technical Panel UTP-2 (Training Technology

Molecular assessment of the membrane menaquinones of irradiated micrococcus on disposable medical devices with high performance liquid chromatography (HPLC)

NASA Astrophysics Data System (ADS)

Ghojaie, M.

1993-10-01

The genus of micrococcus and its main species like; M. Roseus, M. Nishinomiyansis consist of upto 10% of microbial contamination of disposable medical devices. Chemical alteration of Menuquinones Mainly [MK-7-(H2), MK-8(H2),…] from some Irradiated species of the micrococcus at different doses (500 Gy to 25 kGy; the sterilization dose) are quantitatively evaluated by HPLC.

The Asfora Bullet Cage System Shows Comparable Fusion Rate Success Versus Control Cage in Posterior Lumbar Interbody Fusion in a Randomized Clinical Trial.

PubMed

Morgan, Jeremy P; Miller, Ashley L; Thompson, Paul A; Asfora, Wilson T

2016-04-01

Low back pain and degeneration of the intervertebral disc are an integrated malady that affects millions of Americans. Cage devices used in association with posterior lumbar interbody fusion (PLIF) have been shown to be an effective approach in the treatment of a number of lower spine disorders attributed to degenerative disc disease (DDD). This study was undertaken as part of a U.S. Food and Drug Administration (FDA) Investigational Device Exemption (IDE) study and compares the effectiveness of the Asfora Bullet Cage System (ABCS) to successfully fuse vertebra at one or two levels between L2 and S1 in patients with DDD to an FDA approved comparison device, the Medtronic-Sofamor Danek Inter Fix Threaded Fusion Device (MSDIFD). A total of 257 randomized participants were implanted with either the ABCS device (n = 132) or the MSDIFD device (n = 125) through an open posterior approach using autogenous local bone graft without the use of pedicle screws. Patients were evaluated prior to surgery and at the 24 month (24-M) visit for fusion status, deep tendon reflex status, sensory function, motor function, straight leg raise status, pain, disability, and device safety. Radiological evaluation and statistical analysis were performed by independent professionals. Evaluation of device success was performed at 24-M visit. From the original group of 257 patients, 59 were lost to follow-up. Primary measures of success at the 24-M visit involved pain and function, fusion, neurological status, and device-related adverse events measures. Pain and function improved in both (MSDIFD: 75.7 percent; ABCS: 82.6 percent). Fusion success with all radiographic points at 24-M visits was 79.4 percent MSDIFD and 88.2 percent ABCS. Neurological improvement was seen in both (MSDIFD: 77.0 percent; ABCS: 87.8 percent). One device-related grade 1 adverse event was reported in the MSDIFD group. Disc height preservation was equivalent for single level fusions (MSDIFD: 16.1 percent; ABCS: 20.0 percent) and second level fusions (MSDIFD: 10.7 percent; ABCS: 14.3 percent). General health and well-being improvement was the same (MSDIFD: 37.0 percent; ABCS: 40.0 percent). Subsequent fusion, up to 10 years, was equivalent (MSDIFD: 83.8 percent; ABCS: 91.2). Results for both devices were considered to be satisfactory, with a slight non-significant superiority for the ABCS. From the ABCS device FDA IDE sanctioned study and the review of the literature, we concluded that the Asfora Bullet Cage System is safe, effective and comparable to other interbody fusion devices which are used stand-alone or in conjunction with pedicle screws, rhBMP-2, or autogenous bone harvested from the iliac crest inserted through anterior, lateral or posterior approaches.

Biomechanical Modeling of Split-leg Squat and Heel Raise on the Hybrid Ultimate Lifting Kit (HULK)

NASA Technical Reports Server (NTRS)

Thompson, William K.; Gallo, Christopher A.; Lewandowski, Beth E.; Jagodnik, Kathleen M.; Humphreys, Brad; Funk, Justin; Funk, Nathan; Dewitt, John K.

2016-01-01

Long duration space travel will expose astronauts to extended periods of reduced gravity. Since gravity is not present to aid loading, astronauts will use resistive and aerobic exercise regimes for the duration of the space flight to minimize the loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the area available for an exercise device in the next generation of spacecraft is limited and therefore compact resistance exercise device prototypes are being developed. The Advanced Resistive Exercise Device (ARED) currently on the ISS is being used as a benchmark for the functional performance of these new devices. Biomechanical data collection and computational modeling aid the device design process by quantifying the joint torques and musculoskeletal forces that occur during exercises performed on the prototype devices. Computational models currently use OpenSim software, an open source code for musculoskeletal modeling, with biomechanical input data from subjects for estimation of muscle and joint loads. Subjects are instrumented with reflective markers for motion capture data collection while exercising on the Hybrid Ultimate Lifting Kit (HULK) prototype device. Ground reaction force data is collected with force plates under the feet and device loading is recorded through load cells internal to the HULK. This data is input into the OpenSim biomechanical model, which has been scaled to match the anthropometrics of the test subject, to calculate the loads on the body. Multiple exercises are performed and evaluated during a test session such as a full squat, single leg squat, heel raise and dead lift. Variables for these exercises include applied device load, narrow or wide foot stance, slow or fast cadence and the harness or long bar interface between the test subject and the device. Data from free weights are compared to the resistively loaded exercise device. The focus of this presentation is to summarize the results from the single-leg squat and heel raise exercises performed during three sessions occurring in 2015. Differences in loading configuration, cadence and stance produce differences in kinematics, joint toques and force and muscle forces.

Investigations into Performance and Lifetime Enhancements of OPV Devices: Cooperative Research and Development Final Report, CRADA Number CRD-08-263

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

Ginley, D.

2014-06-01

To evaluate Plextronics new additives and derivatives in lithium-ion Battery Applications, Plextronics will provide to NREL, a starting point, including materials and initial data for proof of concept. The central focus of this project is to acertain the nature of the efficacy of the Plextronics additives through physical and electrical characterization, including evaluations of new derivatives, system evaluations on batteries made with Plexcore and to study long term cycling performance differences. The initial focus is to establish Plexcore mode of action to support the commercialization of the first commercial evaluations of Plexcore in Sept. 2013.

Morphological study of electrophoretically deposited TiO2 film for DSSC application

NASA Astrophysics Data System (ADS)

Patel, Alkesh B.; Patel, K. D.; Soni, S. S.; Sonigara, K. K.

2018-05-01

In the immerging field of eco-friendly and low cost photovoltaic devices, dye sensitized solar cell (DSSC) [1] has been investigated as promising alternative to the conventional silicon-based solar cells. In the DSSC device, photoanode is crucial component that take charge of holding sensitizer on it and inject the electrons from the sensitizer to current collector. Nanoporous TiO2 is the most relevant candidate for the preparation of photoanode in DSSCs. Surface properties, morphology, porosity and thickness of TiO2 film as well as preparation technique determine the performance of device. In the present work we have report the study of an effect of nanoporous anatase titanium dioxide (TiO2) film thickness on DSSC performance. Photoanode TiO2 (P25) film was deposited on conducting substrate by electrophoresis technique (EPD) and film thickness was controlled during deposition by applying different current density for a constant time interval. Thickness and surface morphology of prepared films was studied by SEM and transmittance analysis. The same set of photoanode was utilized in DSSC devices using metal free organic dye sensitizer to evaluate the photovoltaic performance. Devices were characterized through Current-Voltage (I-V) characteristic, electrochemical impedance spectroscopy (EIS) and open circuit voltage decay curves. Dependency of device performance corresponding to TiO2 film thickness is investigated through the lifetime kinetics of electron charge transfer mechanism trough impedance fitting. It is concluded that appropriate thickness along with uniformity and porosity are required to align the dye molecules to respond efficiently the incident light photons.

Optimizing the Combination of Acoustic and Electric Hearing in the Implanted Ear

PubMed Central

Karsten, Sue A.; Turner, Christopher W.; Brown, Carolyn J.; Jeon, Eun Kyung; Abbas, Paul J.; Gantz, Bruce J.

2016-01-01

Objectives The aim of this study was to determine an optimal approach to program combined acoustic plus electric (A+E) hearing devices in the same ear to maximize speech-recognition performance. Design Ten participants with at least 1 year of experience using Nucleus Hybrid (short electrode) A+E devices were evaluated across three different fitting conditions that varied in the frequency ranges assigned to the acoustically and electrically presented portions of the spectrum. Real-ear measurements were used to optimize the acoustic component for each participant, and the acoustic stimulation was then held constant across conditions. The lower boundary of the electric frequency range was systematically varied to create three conditions with respect to the upper boundary of the acoustic spectrum: Meet, Overlap, and Gap programming. Consonant recognition in quiet and speech recognition in competing-talker babble were evaluated after participants were given the opportunity to adapt by using the experimental programs in their typical everyday listening situations. Participants provided subjective ratings and evaluations for each fitting condition. Results There were no significant differences in performance between conditions (Meet, Overlap, Gap) for consonant recognition in quiet. A significant decrement in performance was measured for the Overlap fitting condition for speech recognition in babble. Subjective ratings indicated a significant preference for the Meet fitting regimen. Conclusions Participants using the Hybrid ipsilateral A+E device generally performed better when the acoustic and electric spectra were programmed to meet at a single frequency region, as opposed to a gap or overlap. Although there is no particular advantage for the Meet fitting strategy for recognition of consonants in quiet, the advantage becomes evident for speech recognition in competing-talker babble and in patient preferences. PMID:23059851

77 FR 11199 - Visual-Manual NHTSA Driver Distraction Guidelines for In-Vehicle Electronic Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

...The National Highway Traffic Safety Administration (NHTSA) is concerned about the effects of distraction due to drivers' use of electronic devices on motor vehicle safety. Consequently, NHTSA is issuing nonbinding, voluntary NHTSA Driver Distraction Guidelines (NHTSA Guidelines) to promote safety by discouraging the introduction of excessively distracting devices in vehicles. This notice details the contents of the first phase of the NHTSA Driver Distraction Guidelines. These NHTSA Guidelines cover original equipment in-vehicle device secondary tasks (communications, entertainment, information gathering, and navigation tasks not required to drive are considered secondary tasks) performed by the driver through visual-manual means (meaning the driver looking at a device, manipulating a device-related control with the driver's hand, and watching for visual feedback). The proposed NHTSA Guidelines list certain secondary, non-driving related tasks that, based on NHTSA's research, are believed by the agency to interfere inherently with a driver's ability to safely control the vehicle. The Guidelines recommend that those in-vehicle devices be designed so that they cannot be used by the driver to perform such tasks while the driver is driving. For all other secondary, non-driving-related visual-manual tasks, the NHTSA Guidelines specify a test method for measuring the impact of task performance on driving safety while driving and time-based acceptance criteria for assessing whether a task interferes too much with driver attention to be suitable to perform while driving. If a task does not meet the acceptance criteria, the NHTSA Guidelines recommend that in- vehicle devices be designed so that the task cannot be performed by the driver while driving. In addition to identifying inherently distracting tasks and providing a means for measuring and evaluating the level of distraction associated with other non-driving-related tasks, the NHTSA Guidelines contain several design recommendations for in-vehicle devices in order to minimize their potential for distraction. NHTSA seeks comments on these NHTSA Guidelines and any suggestions for how to improve them so as to better enhance motor vehicle safety.

Accelerated testing for studying pavement design and performance (FY 2001) : evaluation of the performance of permeable and semi-permeable unbound granular bases under Portland Cement Concrete Pavement (PCCP) slabs and alternate load transfer devices for

DOT National Transportation Integrated Search

2003-11-01

The objectives of this research are to determine the effect of unbound drainable base types on the performance of PCCP and the efficiency of fiber-reinforced polymer (FRP) dowels, compared to epoxy coated steel dowels, when retrofitted to re-establis...

Evaluation of mobile micro-sensing devices for GPS-based personal exposure monitoring of heat and particulate matter - a matter of context

NASA Astrophysics Data System (ADS)

Ueberham, Maximilian; Schlink, Uwe; Weiland, Ulrike

2017-04-01

The application of mobile micro-sensing devices (MSDs) for human health and personal exposure monitoring (PEM) is an emerging topic of interest in urban air quality research. In the context of climate change, urban population growth and related anthropogenic activities, an increase is expected for the intensity of citizens' exposure to heat and particulate matter (PM). Therefore more focus on the small-scale perspective of spatio-temporal distribution of air quality parameters is important to complement fixed-monitoring site data. Mobile sensors for PEM are useful for both, the investigation of the local distribution of air quality and the personal exposure profiles of individuals moving within their activity spaces. An evaluation of MSDs' accuracy is crucial, before their sophisticated application in measurement campaigns. To detect variations of exposure at small scales, it is even more important to consider the accuracy of Global Positioning System (GPS) devices within different urban structure types (USTs). We present an assessment of the performance of GPS-based MSDs under indoor laboratory conditions and outdoor testing within different USTs. The aim was to evaluate the accuracy of several GPS devices and MSDs for heat and PM 2.5 in relation to reliable standard sensing devices as part of a PhD-project. The performance parameters are summary measures (mean value, standard deviation), correlation (Pearson r), difference measures (mean bias error, mean absolute error, index of agreement) and Bland-Altman plots. The MSDs have been tested in a climate chamber under constant temperature and relative humidity. For temperature MSDs reaction time was tested because of its relevance to detect temperature variations during mobile measurements. For interpretation of the results we considered the MSDs design and technology (e.g. passive vs. active ventilation). GPS-devices have been tested within low/high dense urban residential areas and low/high dense urban green areas and have been compared according to their deviation from the original test route and according to their technology (GPS, A-GPS, GSM, WLAN). In result the performance of the MSDs varies spatially and temporally. Variations mainly depend on the USTs, meteorological conditions, device design and technology. However, the sensors' variation for GPS (3-7m) temperature (1-1.3°C) and PM (800-1100 particles/cu ft) is quite stable over the whole range of value records. Difference measures can be used to consider and correct for mean errors. Furthermore we show that smartphone based GPS-tracking in combination with connected MSDs are a reliable easy-to-use method for PEM. In conclusion our evaluation underpins the applicability of MSDs in combination with GPS for PEM. We observed that especially relative changes in the environmental conditions can be well detected by the devices. Nevertheless, data quality of MSDs remains a relevant concern that needs more investigation especially for applications in citizen science. Eventually the usefulness of mobile MSDs mainly needs to be evaluated depending on the context of application.

Effects of Wave Energy Converter (WEC) Arrays on Wave, Current, and Sediment Circulation

NASA Astrophysics Data System (ADS)

Ruehl, K.; Roberts, J. D.; Jones, C.; Magalen, J.; James, S. C.

2012-12-01

The characterization of the physical environment and commensurate alteration of that environment due to Wave Energy Conversion (WEC) devices, or arrays of devices, must be understood to make informed device-performance predictions, specifications of hydrodynamic loads, and environmental evaluations of eco-system responses (e.g., changes to circulation patterns, sediment dynamics, and water quality). Hydrodynamic and sediment issues associated with performance of wave-energy devices will primarily be nearshore where WEC infrastructure (e.g., anchors, piles) are exposed to large forces from the surface-wave action and currents. Wave-energy devices will be subject to additional corrosion, fouling, and wear of moving parts caused by suspended sediments in the water column. The alteration of the circulation and sediment transport patterns may also alter local ecosystems through changes in benthic habitat, circulation patterns, or other environmental parameters. Sandia National Laboratories is developing tools and performing studies to quantitatively characterize the environments where WEC devices may be installed and to assess potential affects to hydrodynamics and local sediment transport. The primary tools are wave, hydrodynamic, and sediment transport models. To ensure confidence in the resulting evaluation of system-wide effects, the models are appropriately constrained and validated with measured data where available. An extension of the US EPA's EFDC code, SNL-EFDC, provides a suitable platform for modeling the necessary hydrodynamics;it has been modified to directly incorporate output from a SWAN wave model of the region. Model development and results are presented. In this work, a model is exercised for Monterey Bay, near Santa Cruz where a WEC array could be deployed. Santa Cruz is located on the northern coast of Monterey Bay, in Central California, USA. This site was selected for preliminary research due to the readily available historical hydrodynamic data (currents and wave heights, periods, and directions), sediment characterization data, and near-shore bathymetric data. In addition, the region has been under evaluation for future ocean energy projects. The modeling framework of SWAN and SNL-EFDC combined with field validation datasets allows for a robust quantitative description of the nearshore environment within which the MHK devices will be evaluated. This quantitative description can be directly incorporated into environmental impact assessments to eliminate guesswork related to the effects of the presence of large-scale arrays. These results can be used to design more efficient arrays while minimizing impacts on the nearshore environments. Further investigations into fine-scale scour near the structures will help determine if these large-scale results show that, in fact, there is deposition adjacent to the arrays, which could have design implications on anchorage and cabling systems.