Quantitative Gait Measurement with Wave Doppler-radar for Elderly Walking Speed Recognition

Abstract : This paper studies the use of a device based on a Doppler sensor in estimating the gait velocity in a non-controlled environment. It provides signals of the instantaneous velocity with an irregular time sampling. A high accuracy motion capture system, Vicon, was employed to provide the reference data for device evaluation. The gait parameters have been validated with a Vicon motion capture system in our lab. A proper algorithm based on the Lomb-Scargle periodogram was proposed to extract features from the radar signals such as the dominant frequency and the number of steps performed. These features were then used to calculate gait parameters such as the gait velocity and the step duration on a 5m walking sequence at a normal pace. The results showed the reliability of the Doppler device in estimating the gait velocity (mean error = 5.1%).