Doppler Radar System for an Automatic Transfer Phase Detection Using Wavelet Transform Analysis

Nowadays, several needs and interests of older adults must be taken into consideration. In this research, we highlight on the need of in-home gait monitoring. In general, health care professionals refer to mobility assessment tests to evaluate the functional status of elderly people. Most of these tests are accomplished in clinics through gait and transfer tasks such as walking a certain distance and turning while walking. Accordingly, the main objective of this study focuses on providing a continuous assessment technique with a daily basis records. Hence, we intend to automatically detect a transfer phase while walking in home. Our methodology is based on a Doppler radar system with a continuous wavelet transform analysis. Ten statistical parameters were extracted from the coefficient matrix. Results revealed that the variance is a valuable parameter to distinguish between walking and turning phases. Accordingly, DARC algorithm was then applied on the cumulative signal of variance to automatically determine the starting and ending point of a turning phase. The results were validated with a high accuracy motion-capture system (Vicon) with a 0.13% of error.