Development of a Portable System for Physical Activity Assessment in a Home Environment

Abstract

Quantitative assessment of daily physical activity in a home environment provides significant information in evaluation of health and the quality of life of subjects with limited mobility and chronic diseases. This study developed a system for human physical activity assessment in ambulatory monitoring using only one portable sensing device combining a tri-axial accelerometer and its distributed data processing platform. This real-time system is able to identify several postures, posture transitions and movements with the embedded algorithm. In addition, this system also features fall detection capability. The results of the test for evaluating the performance of the system show high identification accuracy for both still postures and dynamic movements. A long-term ambulatory test was also conducted, and the recorded data shows sufficient information of the subject’s activities of daily living at home. Some inherent limitations concerning real-time identification were discussed. Despite those limitations, this system is technically viable for ambulatory application to provide sufficient information in evaluating a person’s activity of daily living (ADL) and his status of physical mobility. Potential wok of this system in the future is also discussed.