Assessing physical performance in free-living older adults with a wearable computer

This study investigates the use of a chest-worn wearable computer, the eButton, to assess physical performance of older adults. The Short Physical Performance Battery (SPPB), a standard clinical test, is first conducted on older human subjects. Then, a triaxial accelerometer and a triaxial gyroscope within the eButton are utilized to record acceleration and angular velocity of body motion on the same subjects for one week. The sensor data corresponding to walking episodes are segmented and features in the time and frequency domains are extracted. Comparison between these features and the total SPPB scores shows that the sensor data acquired in free-living conditions can be used as indicators of the subjects physical performance.