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Background: 

Digital physical ability self-assessments offer an accessible alternative to resource-intensive objective assessments, but their outcomes depend on how well user interfaces (UIs) support correct exercise execution and self-assessment.

Methods: 

This study examined how UI design influences users' interpretation, execution, and self-assessment when using a digital physical ability test. Adopting an iterative, user-centered design approach, six prototype versions were developed and evaluated across four usability phases. Twenty-four working-age adults participated in think-aloud usability tests while performing a single instructionally complex test exercise (Tempo-guided chair squat). Video-recorded sessions were qualitatively analyzed to identify recurring usability breakdowns and examine how UI design shaped participants' self-assessments in relation to researchers' assessment across design iterations.

Results: 

Iterative usability testing revealed recurring breakdowns in how participants interpreted and acted on the test exercise instructions. Key usability issues included misinterpretation of tempo cues, unclear boundaries between correct and incorrect execution, loss of repetition-count awareness, insufficient visual support during execution, overlooked safety-critical setup information, interface inconsistencies, misunderstanding of exercise-relevant concepts, and misaligned self-assessment criteria. These issues led to systematic execution errors and misjudgments of execution quality across prototype versions.

Conclusion: 

The findings conceptualize digital physical ability self-assessment as a multi-layered interaction that places sustained cognitive and physical demands on users. The study contributes a set of transferable design principles describing the interactional support required to enable accurate physical-ability self-assessment. While grounded in a specific context, these design principles may offer insights for exercise-based UIs more broadly, although their generalizability requires further validation.

Background

Falls are the leading cause of injury for people of most ages, and the prevalence of falls increases with age. Fall risk is associated with the specific physical abilities balance, strength, and neuromuscular ability. This article describes a set of 12 physical exercises to assess these specific physical abilities related to fall risk.

Method

A convenience sample of 50 participants (26 men — 20–72 years of age, 24 women — 21–73 years of age) were recruited to this feasibility study to evaluate whether the set of 12 physical exercises and combinations of them can be used as a test to identify early weaknesses and severity of weaknesses in specific physical abilities and to get an indication of whether the physical exercises can identify age-related differences in specific physical abilities. They performed the physical exercises barefoot on a non-slippery floor. A test leader ensured that the participants executed the physical exercises correctly and determined whether the participants passed or failed the physical exercises according to pre-set pass criteria.

Results

Eleven of the physical exercises can assess weaknesses in specific physical abilities. In future tests, the physical exercise Short jump should be excluded from the set of physical exercises due to large variations in execution. The 11 participants younger than 30 years of age (8 men, 3 women) did not show any weaknesses. Nineteen of the 29 participants, 30–60 years of age (9 men, 10 women), and all 10 participants above 60 years of age (6 men, 4 women) showed weakness in at least one specific physical ability.

Conclusions

Eleven out of the 12 physical exercises evaluated in this feasibility study and combinations of them can be used to identify weaknesses in specific physical abilities related to fall risk. Performance on physical exercises, alone or in combination, can also be used to determine the severity of the weaknesses in the three specific physical abilities. The results indicate that the physical exercises can identify age-related differences in specific physical abilities.

Electrical bioimpedance (EBI) is widely used for body composition analysis and shows promise for assessing muscle activation during physical activities (PAs), particularly in aging. This study investigated EBI’s sensitivity to age-related changes in muscle function by analyzing data from 40 adult participants divided into young (20–29 years), middle-aged (32–60 years), and older (62–73 years) groups. EBI signals were recorded from the Quadriceps and Extensor Digitorum Longus (EDL) muscles during three PAs: relaxed standing position, squats, and lunges. Key features were extracted to identify age-related differences. Results revealed distinct muscle-specific patterns: In the relaxed standing position, the EDL muscle exhibited a consistent, monotonic decline in the PrePAmagnitude feature from young to old adults, while the Quadriceps muscle displayed greater variability and a non-monotonic trend. Among the dynamic activities, squats revealed the most pronounced age-related differences, with 62.5% of the features showing statistical significance, whereas fewer differences in the features (25%) where shown during lunges. The findings suggest that EBI can detect age-related reductions in muscle activation and neuromuscular coordination, supporting its potential as a non-invasive tool for functional muscle assessment in aging.

Introduction: Exercise physiology investigates the complex and multifaceted human body responses to physical activity (PA). The integration of electrical bioimpedance (EBI) has emerged as a valuable tool for deepening our understanding of muscle activity during exercise.

Method: In this study, we investigate the potential of using the EBI technique for human motion recognition. We analyze EBI signals from the quadriceps muscle and extensor digitorum longus muscle acquired when healthy participants in the range 20–30 years of age performed four lower body PAs, namely squats, lunges, balance walk, and short jumps.

Results: The characteristics of EBI signals are promising for analyzing PAs. Each evaluated PA exhibited unique EBI signal characteristics.

Discussion: The variability in how PAs are executed leads to variations in the EBI signal characteristics, which, in turn, can provide insights into individual differences in how a person executes a specific PA.

The ubiquity of sensors in smart-homes facilitates the support of independent living for older adults and enables cognitive assessment. Notably, there has been a growing interest in utilizing movement traces for identifying signs of cognitive impairment in recent years. In this study, we introduce an innovative approach to identify abnormal indoor movement patterns that may signal cognitive decline. This is achieved through the non-intrusive integration of smart-home sensors, including passive infrared sensors and sensors embedded in everyday objects. The methodology involves visualizing user locomotion traces and discerning interactions with objects on a floor plan representation of the smart-home, and employing different image descriptor features designed for image analysis tasks and synthetic minority oversampling techniques to enhance the methodology. This approach distinguishes itself by its flexibility in effortlessly incorporating additional features through sensor data. A comprehensive analysis, conducted with a substantial dataset obtained from a real smart-home, involving 99 seniors, including those with cognitive diseases, reveals the effectiveness of the proposed functional prototype of the system architecture. The results validate the system’s efficacy in accurately discerning the cognitive status of seniors, achieving a macro-averaged F1-score of 72.22% for the two targeted categories: cognitively healthy and people with dementia. Furthermore, through experimental comparison, our system demonstrates superior performance compared with state-of-the-art methods.

The extraction of relevant features from the photoplethysmography signal for estimating certain physiological parameters is a challenging task. Various feature extraction methods have been proposed in the literature. In this study, we present a novel fiducial point extraction algorithm to detect c and d points from the acceleration photoplethysmogram (APG), namely “CnD”. The algorithm allows for the application of various pre-processing techniques, such as filtering, smoothing, and removing baseline drift; the possibility of calculating first, second, and third photoplethysmography derivatives; and the implementation of algorithms for detecting and highlighting APG fiducial points. An evaluation of the CnD indicated a high level of accuracy in the algorithm’s ability to identify fiducial points. Out of 438 APG fiducial c and d points, the algorithm accurately identified 434 points, resulting in an accuracy rate of 99%. This level of accuracy was consistent across all the test cases, with low error rates. These findings indicate that the algorithm has a high potential for use in practical applications as a reliable method for detecting fiducial points. Thereby, it provides a valuable new resource for researchers and healthcare professionals working in the analysis of photoplethysmography signals.

Accurate bladder monitoring is critical in the management of conditions such as urinary incontinence, voiding dysfunction, and spinal cord injuries. Electrical bioimpedance (EBI) has emerged as a cost-effective and non-invasive approach to monitoring bladder activity in daily life, with particular relevance to patient groups who require measurement of bladder urine volume (BUV) to prevent urinary leakage. However, the impact of activities in daily living (ADLs) on EBI measurements remains incompletely characterized. In this study, we investigated the impact of normal ADLs such as sitting, standing, and walking on EBI measurements using the MAX30009evkit system with four electrodes placed on the lower abdominal area. We developed an algorithm to identify artifacts caused by the different activities from the EBI signals. Our findings demonstrate that various physical activities clearly affected the EBI measurements, indicating the necessity of considering them during bladder monitoring with EBI technology performed during physical activity (or normal ADLs). We also observed that several specific activities could be distinguished based on their impedance values and waveform shapes. Thus, our results provide a better understanding of the impact of physical activity on EBI measurements and highlight the importance of considering such physical activities during EBI measurements in order to enhance the reliability and effectiveness of EBI technology for bladder monitoring.

Cardiovascular diseases (CVDs) are a leading cause of death worldwide, and hypertension is a major risk factor for acquiring CVDs. Early detection and treatment of hypertension can significantly reduce the risk of developing CVDs and related complications. In this study, a linear SVM machine learning model was used to classify subjects as normal or at different stages of hypertension. The features combined statistical parameters derived from the acceleration plethysmography waveforms and clinical parameters extracted from a publicly available dataset. The model achieved an overall accuracy of 87.50% on the validation dataset and 95.35% on the test dataset. The model's true positive rate and positive predictivity was high in all classes, indicating a high accuracy, and precision. This study represents the first attempt to classify cardiovascular conditions using a combination of acceleration photoplethysmogram (APG) features and clinical parameters The study demonstrates the potential of APG analysis as a valuable tool for early detection of hypertension.

Photoplethysmography is a non-invasive technique used for measuring several vital signs and for the identification of individuals with an increased disease risk. Its principle of work is based on detecting changes in blood volume in the microvasculature of the skin through the absorption of light. The extraction of relevant features from the photoplethysmography signal for estimating certain physiological parameters is a challenging task, where various feature extraction methods have been proposed in the literature. In this work, we present PPGFeat, a novel MATLAB toolbox supporting the analysis of raw photoplethysmography waveform data. PPGFeat allows for the application of various preprocessing techniques, such as filtering, smoothing, and removal of baseline drift; the calculation of photoplethysmography derivatives; and the implementation of algorithms for detecting and highlighting photoplethysmography fiducial points. PPGFeat includes a graphical user interface allowing users to perform various operations on photoplethysmography signals and to identify, and if required also adjust, the fiducial points. Evaluating the PPGFeat’s performance in identifying the fiducial points present in the publicly available PPG-BP dataset, resulted in an overall accuracy of 99% and 3038/3066 fiducial points were correctly identified. PPGFeat significantly reduces the risk of errors in identifying inaccurate fiducial points. Thereby, it is providing a valuable new resource for researchers for the analysis of photoplethysmography signals.

Bladder monitoring, including urinary incontinence management and bladder urinary volume monitoring, is a vital part of urological care. Urinary incontinence is a common medical condition affecting the quality of life of more than 420 million people worldwide, and bladder urinary volume is an important indicator to evaluate the function and health of the bladder. Previous studies on non-invasive techniques for urinary incontinence management technology, bladder activity and bladder urine volume monitoring have been conducted. This scoping review outlines the prevalence of bladder monitoring with a focus on recent developments in smart incontinence care wearable devices and the latest technologies for non-invasive bladder urine volume monitoring using ultrasound, optical and electrical bioimpedance techniques. The results found are promising and their application will improve the well-being of the population suffering from neurogenic dysfunction of the bladder and the management of urinary incontinence. The latest research advances in bladder urinary volume monitoring and urinary incontinence management have significantly improved existing market products and solutions and will enable the development of more effective future solutions.