Gait Speed Measurement using a Doppler Radar Sensor for In-Home Functional Capacity Tests

Gait speed is a simple physical function measure associated with key outcomes in the elderly population. Several tests are realized in order to assess the functional capacity of people. For an in-home monitoring of the functional capacity, we propose to use a Doppler radar sensor in order to continuously measure the gait speed of elderly people. We discuss at first how the gait speed is evaluated using the Doppler radar. We note three different phases in the gait speed, namely an acceleration zone, a measured-gait zone, and a deceleration zone. We thus provide a segmentation of the walking in order to automatically distinguish these zones. Experiments are conducted on ten subjects with three different paces in a total of 180 walking patterns. The gait speed obtained by the radar sensor is validated using a Vicon motion-capture system, with a correlation equal to 0.9788. We report an enhancement of 20% in measuring the gait speed as compared to traditional techniques, while removing the need for acceleration and deceleration zones.