Investigation of the barrier performance of disposable isolation gowns.

BACKGROUND: Recent epidemics and pandemics highlighted the need for effective personal protective equipment, including isolation gowns. The most critical property of an isolation gown is its ability to keep liquids and viruses from passing through the gown. Liquid and viral barrier penetration can be measured using laboratory test methods. Association for the Advancement of Medical Instrumentation (AAMI) PB70 standard defines isolation gown barrier performance levels and requirements. In this study, 22 disposable isolation gown models from 6 manufacturers were tested for liquid and viral penetration resistance. METHODS: Standard test methods were used to evaluate water and viral penetration. Test results were evaluated using AAMI PB70 barrier performance criteria for 4 protection levels. RESULTS: Seven of the 22 tested gown models did not pass liquid and viral penetration testing based on AAMI PB70 at the level claimed by the manufacturer. The majority of these failures occurred at the seam and/or tie attachment areas. CONCLUSIONS: The study findings underscore the need for improved processes surrounding activities such as premarket testing and postmarket evaluation of gowns according to standardized test methods by third-party laboratories. This study also supports the recent Food and Drug Administration guidance document that clarified the characteristics of isolation gowns considered to be class II and subject to Food and Drug Administration premarket review. Infection preventionists, hospital purchasers, and safety professionals should seek isolation gowns demonstrating conformance to industry standards from manufacturers.

PulseDB: A large, cleaned dataset based on MIMIC-III and VitalDB for benchmarking cuff-less blood pressure estimation methods.

There has been a growing interest in developing cuff-less blood pressure (BP) estimation methods to enable continuous BP monitoring from electrocardiogram (ECG) and/or photoplethysmogram (PPG) signals. The majority of these methods have been evaluated using publicly-available datasets, however, there exist significant discrepancies across studies with respect to the size, the number of subjects, and the applied pre-processing steps for the data that is eventually used for training and testing the models. Such differences make conducting performance comparison across models largely unfair, and mask the generalization capability of various BP estimation methods. To fill this important gap, this paper presents "PulseDB," the largest cleaned dataset to date, for benchmarking BP estimation models that also fulfills the requirements of standardized testing protocols. PulseDB contains 1) 5,245,454 high-quality 10 -s segments of ECG, PPG, and arterial BP (ABP) waveforms from 5,361 subjects retrieved from the MIMIC-III waveform database matched subset and the VitalDB database; 2) subjects' identification and demographic information, that can be utilized as additional input features to improve the performance of BP estimation models, or to evaluate the generalizability of the models to data from unseen subjects; and 3) positions of the characteristic points of the ECG/PPG signals, making PulseDB directly usable for training deep learning models with minimal data pre-processing. Additionally, using this dataset, we conduct the first study to provide insights about the performance gap between calibration-based and calibration-free testing approaches for evaluating generalizability of the BP estimation models. We expect PulseDB, as a user-friendly, large, comprehensive and multi-functional dataset, to be used as a reliable source for the evaluation of cuff-less BP estimation methods.

Targeting redox-altered plasticity to reactivate synaptic function: A novel therapeutic strategy for cognitive disorder.

Redox-altered plasticity refers to redox-dependent reversible changes in synaptic plasticity via altering functions of key proteins, such as N-methyl-d-aspartate receptor (NMDAR). Age-related cognitive disorders includes Alzheimer's disease (AD), vascular dementia (VD), and age-associated memory impairment (AAMI). Based on the critical role of NMDAR-dependent long-term potentiation (LTP) in memory, the increase of reactive oxygen species in cognitive disorders, and the sensitivity of NMDAR to the redox status, converging lines have suggested the redox-altered NMDAR-dependent plasticity might underlie the synaptic dysfunctions associated with cognitive disorders. In this review, we summarize the involvement of redox-altered plasticity in cognitive disorders by presenting the available evidence. According to reports from our laboratory and other groups, this "redox-altered plasticity" is more similar to functional changes rather than organic injuries, and strategies targeting redox-altered plasticity using pharmacological agents might reverse synaptic dysfunctions and memory abnormalities in the early stage of cognitive disorders. Targeting redox modifications for NMDARs may serve as a novel therapeutic strategy for memory deficits.

Electrocardiogram heartbeat classification based on a deep convolutional neural network and focal loss.

The electrocardiogram (ECG) is an effective tool for cardiovascular disease diagnosis and arrhythmia detection. Most methods proposed in the literature include the following steps: 1) denoizing, 2) segmentation into heartbeats, 3) feature extraction, and 4) classification. In this paper, we present a deep learning method based on a convolutional neural network (CNN) model. CNN models can perform feature extraction automatically and jointly with the classification step. In other words, our proposed method does not require a feature extraction step with hand-crafted techniques. Our proposed method is also based on an algorithm for heartbeat segmentation that is different from most existing methods. In particular, the segmentation algorithm defines each ECG heartbeat to start at an R-peak and end after 1.2 times the median RR time interval in a 10-s window. This method is simple and effective, as it does not use any form of filtering or processing that requires assumptions about the signal morphology or spectrum. Although enhanced ECG heartbeat classification algorithms have been proposed in the literature, they failed to achieve high performance in detecting some heartbeat categories, especially for imbalanced datasets. To overcome this challenge, we propose an optimization step for the deep CNN model using a novel loss function called focal loss. This function focuses on minority heartbeat classes by increasing their importance. We trained and evaluated our proposed model with the MIT-BIH and INCART datasets to identify five arrhythmia categories (N, S, V, Q, and F) based on the Association for Advancement of Medical Instrumentation (AAMI) standard. The evaluation results revealed that the focal loss function improved the classification accuracy for the minority classes as well as the overall metrics. Our proposed method achieved 98.41% overall accuracy, 98.38% overall F1-score, 98.37% overall precision, and 98.41% overall recall. In addition, our method achieved better performance than that of existing state-of-the-art methods.

Validation of a wrist-type home nocturnal blood pressure monitor in the sitting and supine position according to the ANSI/AAMI/ISO81060-2:2013 guidelines: Omron HEM-9601T.

This study aimed to validate the accuracy of the Omron HEM-9601T, an automatic wrist-type device for self-blood pressure (BP) measurement with a timer function for automatic measurement of nocturnal BP, in the sitting position according to the American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 guidelines, and to assess its performance in the supine position by applying the same protocol as conducted in the sitting position. The mean differences between the reference BPs and HEM-9601T readings were 1.2 ± 6.9/1.1 ± 5.5 mmHg, 2.2 ± 6.5/1.8 ± 5.7 mmHg, 0.1 ± 6.6/1.5 ± 6.2 mmHg, and -0.8 ± 7.2/0.5 ± 6.4 mmHg for systolic BP/diastolic BP for criterion 1 in the sitting position, supine with sideways palm position, supine with upward palm position, and supine with downward palm position, respectively. In addition, the mean differences and their standard deviations for systolic BP and diastolic BP calculated according to criterion 2 in the ANSI/AAMI/ISO 81060-2:2013 guidelines were acceptable in all four positions. In conclusion, the Omron HEM-9601T fulfilled the validation criteria of the ANSI/AAMI/ISO81060-2:2013 guidelines when used in the sitting position with the wrist at heart level, and its accuracy in the supine position was acceptable and roughly equivalent to that in the sitting position. The wrist-type home BP monitor could be a more suitable tool for repeated nocturnal BP measurements at home than upper-arm devices, and could improve the reliability of diagnosis and management of nocturnal hypertension.

Probiotics modulate the microbiota-gut-brain axis and improve memory deficits in aged SAMP8 mice.

ProBiotic-4 is a probiotic preparation composed of Bifidobacterium lactis, Lactobacillus casei, Bifidobacterium bifidum, and Lactobacillus acidophilus. This study aims to investigate the effects of ProBiotic-4 on the microbiota-gut-brain axis and cognitive deficits, and to explore the underlying molecular mechanism using senescence-accelerated mouse prone 8 (SAMP8) mice. ProBiotic-4 was orally administered to 9-month-old SAMP8 mice for 12 weeks. We observed that ProBiotic-4 significantly improved the memory deficits, cerebral neuronal and synaptic injuries, glial activation, and microbiota composition in the feces and brains of aged SAMP8 mice. ProBiotic-4 substantially attenuated aging-related disruption of the intestinal barrier and blood-brain barrier, decreased interleukin-6 and tumor necrosis factor-α at both mRNA and protein levels, reduced plasma and cerebral lipopolysaccharide (LPS) concentration, toll-like receptor 4 (TLR4) expression, and nuclear factor-κB (NF-κB) nuclear translocation in the brain. In addition, not only did ProBiotic-4 significantly decreased the levels of γ-H2AX, 8-hydroxydesoxyguanosine, and retinoic-acid-inducible gene-I (RIG-I), it also abrogated RIG-I multimerization in the brain. These findings suggest that targeting gut microbiota with probiotics may have a therapeutic potential for the deficits of the microbiota-gut-brain axis and cognitive function in aging, and that its mechanism is associated with inhibition of both TLR4-and RIG-I-mediated NF-κB signaling pathway and inflammatory responses.

Validation of two watch-type wearable blood pressure monitors according to the ANSI/AAMI/ISO81060-2:2013 guidelines: Omron HEM-6410T-ZM and HEM-6410T-ZL.

There is growing evidence of the clinical significance of daytime masked hypertension (MHT) and blood pressure (BP) variability (BPV). Recently, watch-type wearable devices for self-BP measurement have become available. Such devices might be promising tools to identify patients with daytime MHT or large BPV in their real-life conditions. The present study aimed to validate the accuracy of the Omron HEM-6410T-ZM and the Omron HEM-6410T-ZL, which are automatic watch-type wearable devices for self-BP measurement, according to the American National Standards Institute, Inc/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 guideline. Watches were held with the wrist at heart level. The mean differences between reference BPs and HEM-6410T-ZM readings were -0.9 ± 7.6/-1.1 ± 6.1 mm Hg for systolic BP (SBP)/diastolic BP (DBP) for criterion 1, and -0.9 ± 6.8/-1.1 ± 5.5 mm Hg for SBP/DBP for criterion 2. The mean differences between reference BPs and HEM-6410T-ZL readings were 2.4 ± 7.3/0.7 ± 7.0 mm Hg for SBP/DBP for criterion 1, and 2.4 ± 6.5/0.7 ± 6.5 mm Hg for SBP/DBP for criterion 2. The Omron HEM-6410T-ZM and the Omron HEM-6410T-ZL both fulfilled both validation criteria 1 and 2 of the ANSI/AAMI/ISO 81060-2:2013 guidelines.

Validation of a wrist-type home nocturnal blood pressure monitor in the sitting and supine position according to the ANSI/AAMI/ISO81060-2:2013 guidelines: Omron HEM-9600T.

The purpose of the present study was to evaluate the performance of the Omron HEM-9600T, an automatic wrist-type device for self BP measurement, in the sitting position with the wrist at heart level and supine position according to the ANSI/AAMI/ISO81060-2:2013 guidelines. In the supine position, we evaluated the device under 3 different conditions: using the supine with sideways palm position, the supine with upwards palm position, and the supine with downwards palm position. After 106 subjects were screened and 21 subjects were excluded, the same 85 subjects (38 men [44.7%] and 47 women [55.3%]) were included in the analyses for each position. The average age of the subjects was 54.5 ± 12.2 years (mean ± SD). The mean wrist circumference was 17.0 ± 2.4 cm. The wrist size distribution fulfilled the requirements of the guidelines. The mean differences between reference BPs and HEM-9600T readings were 1.0 ± 6.7/1.4 ± 5.7 mm Hg, 6.6 ± 7.2/5.5 ± 6.0 mm Hg, 4.8 ± 7.2/4.9 ± 5.8 mm Hg, and 2.1 ± 7.2/2.8 ± 6.8 mm Hg for SBP/DBP in the sitting position, supine with sideways palm position, supine with upwards palm position, and supine with downwards palm position, respectively. In conclusion, the Omron HEM-9600T in the sitting position fulfilled the validation criteria of the ANSI/AAMI/ISO81060-2:2013 guidelines. On the other hand, the accuracies of HEM-9600T in the supine position differed depending on the positioning of the palm, with only the downwards palm-position measurement fulfilling both validation criteria of the ANSI/AAMI/ISO81060-2:2013 guidelines.

Development and Validation of a Novel Cuff-Less Blood Pressure Monitoring Device.

Ordinary cuff-based blood pressure-monitoring devices remain a technical limitation that disturbs activities of daily life. Here we report a novel system for the cuff-less blood pressure estimation (CLB) that requires only 1 sensor for photoplethysmography. The present study is the first report to validate and assess the clinical application of the CLB in accordance with the latest wearable device standard (issued by the Institute of Electrical and Electronics Engineers, standard 1708-2014). Our CLB is expected to offer a flexible and wearable device that permits blood pressure monitoring in more continuous and stress-free settings.

ANÁLISIS COMPARATIVO DE MODELOS DE GESTIÓN DE TECNOLOGÍA BIOMÉDICA / COMPARATIVE ANALYSIS OF BIOMEDICAL TECHNOLOGY MANAGEMENT MODELS / A ANÁLISE COMPARATIVA DOS MODELOS DE GESTÃO DE TECNOLOGIA BIOMÉDICA

La gestión de tecnología en salud es un elemento clave para garantizar una atención segura y de calidad a los pacientes. Muchas instituciones han diseñado modelos de gestión orientados a cumplir ese objetivo. En este trabajo se realiza un análisis comparativo de los modelos propuestos por asociaciones como American College of Clinical Engineering (ACCE), Association for the Advancement of Medical Instrumentation (AAMI), Medicines and Healthcare Products Regulatory (MHRA) y una guía del Ministerio de la Protección Social de Colombia (MPS). Además de dos metodologías de evaluación de tecnología: una tesis de doctorado de la Universidad Federal de Santa Catarina (UFSC) y la propuesta del Centro Nacional de Excelencia Tecnológica en Salud (CENETEC). Posteriormente se identifican las ventajas y desventajas de cada uno de ellos. Los resultados del estudio indican que cada modelo tiene fortalezas que pueden ser aprovechadas en la construcción de un modelo consenso acorde con las necesidades de las Instituciones prestadoras de salud (IPS) del país y las condiciones de funcionamiento del sistema de salud colombiano.

The management of health technology is a key element to ensuring safe, quality patient care. Many institutions have designed management models focused on achieving this goal. This paper presents a comparative analysis of the models proposed by associations such as the American College of Clinical Engineering (ACCE), Association for the Advancement of Medical Instrumentation (AAMI), the Medicines and Healthcare Products Regulatory Agency (MHRA) and a guide done by the Ministry of Social Protection of Colombia (MPS). Two technology assessment methodologies were used: a doctoral thesis at the Federal University of Santa Catarina (UFSC) and the proposal made by the National Center for Health Technology Excellence (CENETEC). Subsequently the advantages and disadvantages of each are identified. The study results indicate that each model has strengths that can be exploited in building a consensus model in line with the needs of health institutions (IPS, in Colombia) in the country and the operating conditions of the Colombian health system.

A gestão de tecnologias em saúde é o elemento chave para garantir um atendimento com segurança e de qualidade ao paciente. Muitas instituições têm projetado modelos de gestão destinados a satisfazer esse objetivo. Neste trabalho se apresenta uma análise comparativa dos modelos propostos por associações como American College o Clinical Engineering (ACCE), Association for the Advancement of Medical Instrumentation (AAMI), Medidines and Healthcare Products Regulatory (MHRA) e uma orientação do Ministério da Proteção Social da Colômbia (MPS). Além de duas metodologias de avaliação de tecnologia: uma tese de doutorado na Universidade Federal de Santa Catarina (UFSC) e a proposta do Centro Nacional excelência de Tecnologia em saúde (CENETEC). Subsequentemente, se identificam as vantagens e desvantagens de cada uma delas. Os resultados do estudo indicam que cada modelo tem pontos fortes que podem ser aproveitada na construção de um modelo de consenso em linha com as necessidades das instituições de saúde (IPS) do país e as condições de funcionamento do sistema de saúde colombiano.

Validation of two automatic devices for the self-measurement of blood pressure according to the ANSI/AAMI/ISO81060-2:2009 guidelines: the Omron BP765 (HEM-7311-ZSA) and the Omron BP760N (HEM-7320-Z).

BACKGROUND: Allowing patients to measure their blood pressure (BP) at home will be the standard for evaluating the disease state as the process of clinical diagnosis, and it is recognized as having great clinical utility. To measure BP as accurately as possible, innovative techniques have been incorporated into home BP measurement devices. OBJECTIVE: The present study aimed to evaluate the performance of the Omron BP765 (HEM-7311-ZSA) and the Omron BP760N (HEM-7320-Z), which are equipped with functions to detect irregular pulses and arm movement that lead to inaccurate BP readings. METHODS: A team of three trained medical doctors validated the performance of these devices by comparing the data alternatively obtained from both devices with those from a standard mercury sphygmomanometer. RESULTS: The magnitude of the difference in BP readings between the tested device and the standard mercury sphygmomanometer in the Omron BP765 and BP760N was within the range of ±3 mmHg (mean) allowed by the American National Standards Institute, Inc/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2009 guidelines. CONCLUSION: The Omron BP765 and BP760N were found useful for the self-measurement of BP at home, and their performance fulfilled the requirement of the ANSI/AAMI/ISO 81060-2:2009 guidelines.

Preserved Suppression of Salient Irrelevant Stimuli During Visual Search in Age-Associated Memory Impairment.

Previous studies have suggested that older adults with age-associated memory impairment (AAMI) may show a significant decline in attentional resource capacity and inhibitory processes in addition to memory impairment. In the present paper, the potential attentional capture by task-irrelevant stimuli was examined in older adults with AAMI compared to healthy older adults using scalp-recorded event-related brain potentials (ERPs). ERPs were recorded during the execution of a visual search task, in which the participants had to detect the presence of a target stimulus that differed from distractors by orientation. To explore the automatic attentional capture phenomenon, an irrelevant distractor stimulus defined by a different feature (color) was also presented without previous knowledge of the participants. A consistent N2pc, an electrophysiological indicator of attentional deployment, was present for target stimuli but not for task-irrelevant color stimuli, suggesting that these irrelevant distractors did not attract attention in AAMI older adults. Furthermore, the N2pc for targets was significantly delayed in AAMI patients compared to healthy older controls. Together, these findings suggest a specific impairment of the attentional selection process of relevant target stimuli in these individuals and indicate that the mechanism of top-down suppression of entirely task-irrelevant stimuli is preserved, at least when the target and the irrelevant stimuli are perceptually very different.

Safe magnetic resonance imaging scanning of patients with cardiac rhythm devices: a role for computer modeling.

BACKGROUND: Although there are several hazards for patients with implanted pacemakers and defibrillators in the magnetic resonance imaging (MRI) environment, evaluation of lead electrode heating is the most complex because of the many influencing variables: patient size, anatomy, body composition, patient position in the bore, scan sequence (radiofrequency power level), lead routing, and lead design. Although clinical studies are an important step in demonstrating efficacy, demonstrating safety through clinical trials alone is not practical because of this complexity. OBJECTIVE: The purpose of this study was to develop a comprehensive modeling framework to predict the probability of pacing capture threshold (PCT) change due to lead electrode heating in the MRI environment and thus provide a robust safety evaluation. METHODS: The lead heating risk was assessed via PCT change because this parameter is the most clinically relevant measure of lead heating. The probability for PCT change was obtained by combining the prediction for power at the electrode-tissue interface obtained via simulations with a prediction for PCT change as a function of radiofrequency power obtained via an in vivo canine study. RESULTS: The human modeling framework predicted that the probability of a 0.5-V PCT change due to an MRI scan for the Medtronic CapSureFix MRI SureScan model 5086 MRI leads is <1/70,000 for chest scans and <1/10,000,000 for either head scans or lower torso scans. CONCLUSION: The framework efficiently models millions of combinations, delivering a robust evaluation of the lead electrode heating hazard. This modeling approach provides a comprehensive safety evaluation that is impossible to achieve using phantom testing, animal studies, or clinical trials alone.

The effect of soybean-derived phosphatidylserine on cognitive performance in elderly with subjective memory complaints: a pilot study.

OBJECTIVE: To evaluate the efficacy and safety of soybean-derived phosphatidylserine (SB-PS) (300 mg/day) in improving cognitive performance in elderly with memory complaints, following a short duration of 12 weeks' SB-PS administration. METHODS: SB-PS was administered daily for 12 weeks to 30 elderly volunteers with memory complaints (age range 50-90 years). Cognitive performance was determined by a computerized test battery and by the Rey Auditory Verbal Learning Test (Rey-AVLT). Physical examination and blood safety parameters were part of the extensive safety analysis of PS that was performed. RESULTS: The computerized test results showed that SB-PS supplementation significantly increased the following cognitive parameters: memory recognition (P = 0.004), memory recall (P = 0.006), executive functions (P = 0.004), and mental flexibility (P = 0.01). The Rey-AVLT indicated that, following SB-PS administration, total learning and immediate recall improved significantly (P = 0.013 and P = 0.007, respectively). Unexpected results from the safety tests suggested that SB-PS significantly reduces both systolic (P = 0.043) and diastolic (P = 0.003) blood pressure. SB-PS consumption was well tolerated and no serious adverse events were reported during the study. CONCLUSION: This exploratory study demonstrates that SB-PS may have favorable effects on cognitive function in elderly with memory complaints. In addition, the study suggests that SB-PS is safe for human consumption and may serve as a safe alternative to phosphatidylserine extracted from bovine cortex. These results encourage further extended studies in order to establish the safety and efficacy of SB-PS treatment.

Validation of Datascope Accutorr Plus™ using British Hypertension Society (BHS) and Association for the Advancement of Medical Instrumentation (AAMI) protocol guidelines.

OBJECTIVE: To assure the accuracy and reliability of blood pressure measurement by non-invasive blood pressure monitor using Datascope Accutorr Plus™ (Paramus, NJ, USA) against mercury manometer, among adult male participants. METHOD: Eighty participants from a family physician's office at a teaching hospital were recruited. One hundred and sixty measurements of blood pressure were performed according to BHS technique protocol. STATISTICAL ANALYSIS: Descriptive analysis was done according to the AAMI and BHS protocol guidelines. The limits of agreement between the device and the standard were plotted using the method of Bland and Altman plot. RESULTS: The mean difference ± SD between the Datascope Acutorr Plus™ and observer was 2.7 ± 5.2 mm Hg and 1.5 ± 3.26 mm Hg for systolic and diastolic blood pressure, respectively. Datascope Acutorr Plus™ obtained A/A grading for both systolic and diastolic blood pressure. CONCLUSION: Datascope Accutorr Plus™ (Paramus, NJ, USA) satisfies BHS and AAMI validation protocols for both systolic and diastolic BP and may be recommended for everyday use for BP monitoring at home and in clinical use for adult population.

Randomized controlled trial of standardized Bacopa monniera extract in age-associated memory impairment.

BACKGROUND: Brahmi (Bacopa monniera) is a traditional Indian medicinal plant which causes multiple effects on the central nervous system. The standardized extract of this plant has shown enhanced behavioural learning in preclinical studies and enhanced information processing in healthy volunteers. AIM: To study the efficacy of standardized Bacopa monniera extract (SBME) in subjects with age-associated memory impairment (AAMI) without any evidence of dementia or psychiatric disorder. METHODS: A double-blind, placebo-controlled randomized study design was employed. The subjects received either 125 mg of SBME or placebo twice a day for a period of 12 weeks followed by a placebo period of another 4 weeks (total duration of the trial 16 weeks). Each subject was evaluated for cognition on a battery of tests comprising mental control, logical memory, digit forward, digit backward, visual reproduction and paired associate learning. RESULTS: SBME produced significant improvement on mental control, logical memory and paired associated learning during the 12-week drug therapy. CONCLUSION: SBME is efficacious in subjects with age-associated memory impairment.