-
Biocontrol Science 2017Ethylene oxide gas is an agent in the sterilization of medical devices due to its effectiveness and compatibility with most materials. The advantages and... (Review)
Review
Ethylene oxide gas is an agent in the sterilization of medical devices due to its effectiveness and compatibility with most materials. The advantages and disadvantages, as well as its recommended uses, are explored in this review article. The variables and their relevance on process optimization are described, the types of processing cycles are detailed and emphasis is given to the design and validation of the sterilization process.
Topics: Alkylation; Environmental Monitoring; Equipment and Supplies; Ethylene Oxide; Gases; Humans; Occupational Exposure; Personal Protective Equipment; Pressure; Sterilization
PubMed: 28367865
DOI: 10.4265/bio.22.1 -
Journal of Diabetes Science and... Mar 2020With the rapid development of new insulin delivery technology, measuring patient experience has become especially pertinent. The current study reports on item...
BACKGROUND
With the rapid development of new insulin delivery technology, measuring patient experience has become especially pertinent. The current study reports on item development, psychometric validation, and intended use of the newly developed Diabetes Impact and Device Satisfaction (DIDS) Scale.
METHOD
The DIDS Scale was informed by a comprehensive literature review, and field tested as part of two focus groups. The finalized measure was used at baseline and 6 months post-assessment with a large US cohort. Exploratory factor analyses (EFAs) were conducted to determine and confirm factor structure and item selection. Internal reliability, test-retest reliability, and convergent/divergent validity of the emerged factors were tested with demographics, diabetes-specific information, and diabetes behavioral and satisfaction measures.
RESULTS
In all, 778 participants with type 1 diabetes (66% female, mean age 47.13 ± 17.76 years, 74% insulin pump users) completed surveys at both baseline and post-assessment. EFA highlighted two factors-Device Satisfaction (seven items, Cronbach's α = 0.85-0.90) and Diabetes Impact (four items, Cronbach's α = 0.71-0.75). DIDS Scale demonstrated good concurrent validity and test-retest reliability.
CONCLUSION
The DIDS Scale is a novel and a brief assessment tool with robust psychometric properties. It is recommended for use across all insulin delivery devices and is considered appropriate for use in longitudinal studies. Future studies are recommended to evaluate the performance of DIDS Scale in diverse populations with diabetes.
Topics: Adult; Aged; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 1; Equipment and Supplies; Female; Glycemic Control; Humans; Insulin; Insulin Infusion Systems; Male; Middle Aged; Patient Satisfaction; Personal Satisfaction; Psychometrics; Reproducibility of Results; Surveys and Questionnaires
PubMed: 32028790
DOI: 10.1177/1932296819897976 -
Sensors (Basel, Switzerland) Apr 2019This paper addresses the significant need for improvements in device version reporting and practice across the academic and technical activity monitoring literature, and...
This paper addresses the significant need for improvements in device version reporting and practice across the academic and technical activity monitoring literature, and it recommends assessments for new and updated consumer sensing devices. Reproducibility and data veracity are central to good scholarship, and particularly significant in clinical and health applications. Across the literature there is an absence of device version reporting and a failure to recognize that device validity is not maintained when firmware and software updates can, and do, change device performance and parameter estimation. In this paper, we propose the use of tractable methods to assess devices and provide an example empirical approach. Experimental results for heart rate and step count acquisitions during walking and everyday living activities from Garmin Vivosmart 3 (v4.10) wristband monitors are presented and analyzed, and the reliability issues of optically-acquired heart rates, especially during periods of activity, are demonstrated and discussed. In conclusion, the paper recommends the empirical assessment of new and updated activity monitors and improvements in device version reporting across the academic and technical literature.
Topics: Accelerometry; Activities of Daily Living; Adult; Exercise Test; Female; Heart Rate; Humans; Male; Middle Aged; Monitoring, Ambulatory; Walking; Wearable Electronic Devices
PubMed: 30974755
DOI: 10.3390/s19071705 -
Gait & Posture Oct 2022Many activity trackers have been developed, but steps can still be inconsistent from one monitor to another.
BACKGROUND
Many activity trackers have been developed, but steps can still be inconsistent from one monitor to another.
RESEARCH QUESTION
What are the differences and associations between the steps of 13 selected consumer-based and research-grade wearable devices during 1 standardized day in a metabolic chamber and 15-day free-living trials?
METHODS
In total, 19 healthy adults between 21 and 50 years-old participated in this study. Participants were equipped with 12 accelerometer-based active trackers and one pedometer (Yamasa) in order to monitor the number of steps per day. The devices were worn on the waist (ActiGraph, Omron, Actimarker, Lifedorder, Withings, and Yamasa) or non-dominant wrist (Fitbit, Garmin, Misfit, EPSON, and Jawbone), or placed in a pocket (Omron CaloriScan, and TANITA). Participants performed structured activities over a 24 h period in a chamber (Standardized day), and steps were monitored in the same participants in free-living trials for 15 successive days using the same monitors (free-living days).
RESULTS
When the 13 monitors were ranked by their steps, waist-worn ActiGraph was located at the center (7th) of the monitors both in the Standardized (12,252 ± 598 steps/day, mean ± SD) and free-living days (9295 ± 4027 steps/day). The correlation between the accelerometer-based devices was very high (r = 0.87-0.99). However, the steps of Yamasa was significantly lower in both trials than ActiGraph. The wrist-worn accelerometers had significantly higher steps than other devices both trials (P < 0.05). The differences between ActiGraph and Actimarker or Lifecorder was less than 100 steps/day in the Standardized day, and the differences between ActiGraph and Active Style Pro was less than 100 steps/day in the free-living days. Regression equation was also performed for inter-device compatibility.
SIGNIFICANCE
Step obtained from the wrist-worn, waist-worn, and pocket-type activity trackers were significantly different from each other but still highly correlated in free-living conditions.
Topics: Adult; Humans; Young Adult; Middle Aged; Fitness Trackers; Accelerometry; Exercise; Actigraphy; Wearable Electronic Devices; Reproducibility of Results
PubMed: 36030707
DOI: 10.1016/j.gaitpost.2022.08.004 -
Anesthesia and Analgesia Dec 2020The bispectral index (BIS) monitor has been available for clinical use for >20 years and has had an immense impact on academic activity in Anesthesiology, with >3000...
BACKGROUND
The bispectral index (BIS) monitor has been available for clinical use for >20 years and has had an immense impact on academic activity in Anesthesiology, with >3000 articles referencing the bispectral index. Despite attempts to infer its algorithms by external observation, its operation has nevertheless remained undescribed, in contrast to the algorithms of other less commercially successful monitors of electroencephalogram (EEG) activity under anesthesia. With the expiration of certain key patents, the time is therefore ripe to examine the operation of the monitor on its own terms through careful dismantling, followed by extraction and examination of its internal software.
METHODS
An A-2000 BIS Monitor (gunmetal blue case, amber monochrome display) was purchased on the secondary market. After identifying the major data processing and storage components, a set of free or inexpensive tools was used to retrieve and disassemble the monitor's onboard software. The software executes primarily on an ARMv7 microprocessor (Sharp/NXP LH77790B) and a digital signal processor (Texas Instruments TMS320C32). The device software can be retrieved directly from the monitor's hardware by using debugging interfaces that have remained in place from its original development.
RESULTS
Critical numerical parameters such as the spectral edge frequency (SEF), total power, and BIS values were retraced from external delivery at the device's serial port back to the point of their calculation in the extracted software. In doing so, the locations of the critical algorithms were determined. To demonstrate the validity of the technique, the algorithms for SEF and total power were disassembled, comprehensively annotated and compared to their theoretically ideal behaviors. A bug was identified in the device's implementation of the SEF algorithm, which can be provoked by a perfectly isoelectric EEG.
CONCLUSIONS
This article demonstrates that the electronic design of the A-2000 BIS Monitor does not pose any insuperable obstacles to retrieving its device software in hexadecimal machine code form directly from the motherboard. This software can be reverse engineered through disassembly and decompilation to reveal the methods by which the BIS monitor implements its algorithms, which ultimately must form the definitive statement of its function. Without further revealing any algorithms that might be considered trade secrets, the manufacturer of the BIS monitor should be encouraged to release the device software in its original format to place BIS-related academic literature on a firm theoretical foundation and to promote further academic development of EEG monitoring algorithms.
Topics: Anesthesiology; Biomedical Engineering; Consciousness Monitors; Electroencephalography; Equipment Design; Humans; Monitoring, Intraoperative
PubMed: 33093360
DOI: 10.1213/ANE.0000000000005220 -
Advanced Healthcare Materials Jul 2022Hotter summers caused by global warming and increased workload and duration are endangering the health of farmworkers, a high-risk population for heat-related illness...
Hotter summers caused by global warming and increased workload and duration are endangering the health of farmworkers, a high-risk population for heat-related illness (HRI), and deaths. Although prior studies using wearable sensors show the feasibility of employing field-collected data for HRI monitoring, existing devices still have limitations, such as data loss from motion artifacts, device discomfort from rigid electronics, difficulties with administering ingestible sensors, and low temporal resolution. Here, this paper introduces a wireless, wearable bioelectronic system with functionalities for continuous monitoring of skin temperature, electrocardiograms (ECG), heart rates (HR), and activities, configured in a single integrated package. Advanced nanomanufacturing based on laser machining allows rapid device fabrication and direct incorporation of sensors with a highly breathable substrate, allowing for managing excessive sweating and multimodal stresses. To validate the device's performance in agricultural settings, the device is applied to multiple farmworkers at various operations, including fernery, nursery, and crop. The accurate data recording, including high-fidelity ECG (signal-to-noise ratio: >20 dB), accurate HR (r = 0.89, r = 0.65 in linear correlation), and reliable temperature/activity, confirms the device's capability for multiparameter health monitoring of farmworkers.
Topics: Electronics; Farmers; Heart Rate; Hot Temperature; Humans; Wearable Electronic Devices; Wireless Technology
PubMed: 35306761
DOI: 10.1002/adhm.202200170 -
NeuroImage Aug 2022Currently, there is great interest in making neuroimaging widely accessible and thus expanding the sampling population for better understanding and preventing diseases....
Currently, there is great interest in making neuroimaging widely accessible and thus expanding the sampling population for better understanding and preventing diseases. The use of wearable health devices has skyrocketed in recent years, allowing continuous assessment of physiological parameters in patients and research cohorts. While most health wearables monitor the heart, lungs and skeletal muscles, devices targeting the brain are currently lacking. To promote brain health in the general population, we developed a novel, low-cost wireless cerebral oximeter called FlexNIRS. The device has 4 LEDs and 3 photodiode detectors arranged in a symmetric geometry, which allows for a self-calibrated multi-distance method to recover cerebral hemoglobin oxygenation (SO) at a rate of 100 Hz. The device is powered by a rechargeable battery and uses Bluetooth Low Energy (BLE) for wireless communication. We developed an Android application for portable data collection and real-time analysis and display. Characterization tests in phantoms and human participants show very low noise (noise-equivalent power <70 fW/√Hz) and robustness of SO quantification in vivo. The estimated cost is on the order of $50/unit for 1000 units, and our goal is to share the device with the research community following an open-source model. The low cost, ease-of-use, smart-phone readiness, accurate SO quantification, real time data quality feedback, and long battery life make prolonged monitoring feasible in low resource settings, including typically medically underserved communities, and enable new community and telehealth applications.
Topics: Brain; Head; Hemoglobins; Humans; Oximetry; Phantoms, Imaging; Wearable Electronic Devices; Wireless Technology
PubMed: 35452803
DOI: 10.1016/j.neuroimage.2022.119216 -
Medicina (Kaunas, Lithuania) Jun 2022: Fracture healing is currently assessed through qualitative evaluation of radiographic images, which is highly subjective in nature. Radiographs can only provide...
: Fracture healing is currently assessed through qualitative evaluation of radiographic images, which is highly subjective in nature. Radiographs can only provide snapshots in time, which are limited due to logistics and radiation exposure. We recently proposed assessing the bone healing status through continuous monitoring of the implant load, utilizing an implanted sensor system, the Fracture Monitor. The device telemetrically transmits statistically derived implant parameters via the patient's mobile phone to assist physicians in diagnostics and treatment decision-making. This preclinical study aims to systematically investigate the device safety and performance in an animal setting. : Mid-shaft tibial osteotomies of different sizes (0.6-30 mm) were created in eleven Swiss mountain sheep. The bones were stabilized with either a conventional Titanium or stainless-steel locking plate equipped with a Fracture Monitor. Data were continuously collected over the device's lifetime. Conventional radiographs and clinical CT scans were taken longitudinally over the study period. The radiographs were systematically scored and CTs were evaluated for normalized bone volume in the defect. The animals were euthanized after 9 months. The sensor output was correlated with the radiologic parameters. Tissue samples from the device location were histologically examined. : The sensors functioned autonomously for 6.5-8.4 months until energy depletion. No macroscopic or microscopic adverse effects from device implantation were observed. The relative implant loads at 4 and 8 weeks post-operation correlated significantly with the radiographic scores and with the normalized bone volume metric. : Continuous implant load monitoring appears as a relevant approach to support and objectify fracture healing assessments and carries a strong potential to enable patient-tailored rehabilitation in the future.
Topics: Animals; Bone Plates; Fracture Fixation, Internal; Fracture Healing; Osteotomy; Sheep; Titanium
PubMed: 35888576
DOI: 10.3390/medicina58070858 -
Translational Vision Science &... Oct 2021This study aimed to custom design, build, and test a removable device that accurately and objectively monitors adherence to spectacle wear in preschool children...
PURPOSE
This study aimed to custom design, build, and test a removable device that accurately and objectively monitors adherence to spectacle wear in preschool children participating in clinical trials. This work will provide researchers with the tools to investigate the effect of adherence to optical treatment in conditions relating to refractive error, such as anisometropia, amblyopia, myopia, and accommodative esotropia, where spectacle wearing behaviors are of interest.
METHODS
Several sensors were considered in the design of the SpecsOn monitor. The final version included two temperature sensors, one that measures skin temperature through an infrared sensor directed at the wearer's temple on the spectacle arm and the other measuring device temperature. The difference between the two temperature readings is used to determine if the spectacles were worn. The SpecsOn monitor was tested in two phases in adult participants (laboratory n = 10 and real world n = 5).
RESULTS
Results from both phases showed good agreement between the objective measurement of wear based on skin and device temperature differences and participants' manually logged wear times. The custom built SpecsOn monitor was 99% successful in accurately detecting spectacle wear in our adult cohort.
CONCLUSIONS
The SpecsOn monitor offers a convenient, accurate, and reliable system to monitor spectacle adherence. The devices were comfortable, secure, and unobtrusive to wear, and fitted easily to a variety of frame styles.
TRANSLATIONAL RELEVANCE
Easy access to spectacle compliance information from the SpecsOn monitor during the optical treatment phase will optimize visual outcomes and provide detailed clinical data to support decision making on the need and timing of additional therapies, improving treatment efficiency.
Topics: Adult; Amblyopia; Child, Preschool; Eyeglasses; Humans; Monitoring, Physiologic; Refractive Errors; Temperature
PubMed: 34614165
DOI: 10.1167/tvst.10.12.11 -
Nature Reviews. Cardiology Feb 2021Ambulatory monitoring is increasingly important for cardiovascular care but is often limited by the unpredictability of cardiovascular events, the intermittent nature of... (Review)
Review
Ambulatory monitoring is increasingly important for cardiovascular care but is often limited by the unpredictability of cardiovascular events, the intermittent nature of ambulatory monitors and the variable clinical significance of recorded data in patients. Technological advances in computing have led to the introduction of novel physiological biosignals that can increase the frequency at which abnormalities in cardiovascular parameters can be detected, making expert-level, automated diagnosis a reality. However, use of these biosignals for diagnosis also raises numerous concerns related to accuracy and actionability within clinical guidelines, in addition to medico-legal and ethical issues. Analytical methods such as machine learning can potentially increase the accuracy and improve the actionability of device-based diagnoses. Coupled with interoperability of data to widen access to all stakeholders, seamless connectivity (an internet of things) and maintenance of anonymity, this approach could ultimately facilitate near-real-time diagnosis and therapy. These tools are increasingly recognized by regulatory agencies and professional medical societies, but several technical and ethical issues remain. In this Review, we describe the current state of cardiovascular monitoring along the continuum from biosignal acquisition to the identification of novel biosensors and the development of analytical techniques and ultimately to regulatory and ethical issues. Furthermore, we outline new paradigms for cardiovascular monitoring.
Topics: Cardiovascular Diseases; Humans; Machine Learning; Monitoring, Ambulatory; Wearable Electronic Devices
PubMed: 33037325
DOI: 10.1038/s41569-020-00445-9