The 2023 wearable photoplethysmography roadmap

Photoplethysmography is a key sensing technology which is used in wearable devices such as smartwatches and fitness trackers. Currently, photoplethysmography sensors are used to monitor physiological parameters including heart rate and heart rhythm, and to track activities like sleep and exercise. Yet, wearable photoplethysmography has potential to provide much more information on health and wellbeing, which could inform clinical decision making. This Roadmap outlines directions for research and development to realise the full potential of wearable photoplethysmography. Experts discuss key topics within the areas of sensor design, signal processing, clinical applications, and research directions. Their perspectives provide valuable guidance to researchers developing wearable photoplethysmography technology

NADI PARIKSHA: WRIST PULSE ANALYSIS WITH TRADITIONAL AND MODERN INTERPRETATION

Nadi Pariksha (Pulse diagnosis) is considered the most important assessment in Traditional Medicine System (TMS) for health monitoring. Traditional pulse analysis is subjective and hard to quantify. It is difficult for a Ayurvedic doctor to understand the pulse by his own perception due to its arbitrariness. To realize due recognition of TMS, standard techniques and standard instruments are urgently to be developed. In view of the increasing popularity of traditional and alternative medicine worldwide, researchers have explored pulse sensing and analysis, but due to the conflict of research goals, methodologies and statistical tools applied, the outcome of studies till date is not focused in one direction. This study explores current status of pulse signal interpretation by researchers using latest electronic signal processing techniques in recent years. The aim of research is towards development of pulse sensing and analyzing techniques using latest technology to assist or help Ayurvedic doctors, in a way to promote our countrys traditional pulse sensing. Since no sensor is benchmarked as a standard in wrist pulse sensing till date, various sensors were explored to sense wrist pulse and the results were correlated with the recent research. Optical sensor HOA 709 in reflective mode, exhibited best results, it captured the minute details and was used to acquire pulse signal of healthy subjects at Pita point on radial artery. The sensor was explored further to record pre-meal and post-meal data of two subjects and significant variation in signal contour was noticed. It can further be explored to extract more parameters with the help of Ayurvedic doctors to make it useful in health care.

Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography

The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave)

Biomedical and Human Factors Requirements for a Manned Earth Orbiting Station

This report is the result of a study conducted by Republic Aviation Corporation in conjunction with Spacelabs, Inc.,in a team effort in which Republic Aviation Corporation was prime contractor. In order to determine the realistic engineering design requirements associated with the medical and human factors problems of a manned space station, an interdisciplinary team of personnel from the Research and Space Divisions was organized. This team included engineers, physicians, physiologists, psychologists, and physicists. Recognizing that the value of the study is dependent upon medical judgments as well as more quantifiable factors (such as design parameters) a group of highly qualified medical consultants participated in working sessions to determine which medical measurements are required to meet the objectives of the study. In addition, various Life Sciences personnel from NASA (Headquarters, Langley, MSC) participated in monthly review sessions. The organization, team members, consultants, and some of the part-time contributors are shown in Figure 1. This final report embodies contributions from all of these participants

A Novel Method for Classification of Wrist Pulse for Health Monitoring using Sparse Classifier

A wrist pulse system has been developed that can detect both normal and abnormal conditions in patients based on wrist pulse diagnosis. Pulse diagnosis are mainly done in three steps they are pulse preprocessing, feature extraction and classification. The acquired wrist pulse signal is passed through consecutive stages of denoising, baseline wander removal and period segmentation. The feature extraction is then done to extract time domain, frequency domain and wavelet features. Classification is then done for finding normal and abnormal conditions using SVM (Support Vector Machine) classifier. It is found that by using the SVM classifier, distributed features cannot be efficiently identified, classification accuracy is low and sub-classification cannot be done for abnormal condition as SVM supports only binary data. So SVM classifier is replaced by sparse classifier which has higher accuracy since it supports highly nonlinear data. T test is used in feature selection so that it needs low memory and less time consumption. Sub-classification has been done for the abnormal cases of Anemia, Arrhythmia, Tuberculosis and Wolff Parkinson White Syndrome

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 237

A bibliography is given on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the Earth's atmosphere or in interplanetary space. References describing similar effects of biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. In general, emphasis is placed on applied research, but references to fundamental studies and theoretical principles related to experimental development also qualify for inclusion

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 171

This bibliography lists 186 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1977

Vagus nerve stimulation: State of the art of stimulation and recording strategies to address autonomic function neuromodulation

International audienceObjective. Neural signals along the vagus nerve (VN) drive many somatic and autonomic functions. The clinical interest of VN stimulation (VNS) is thus potentially huge and has already been demonstrated in epilepsy. However, side effects are often elicited, in addition to the targeted neuromodulation. Approach. This review examines the state of the art of VNS applied to two emerging modulations of autonomic function: heart failure and obesity, especially morbid obesity. Main results. We report that VNS may benefit from improved stimulation delivery using very advanced technologies. However, most of the results from fundamental animal studies still need to be demonstrated in humans