Heartbeat monitoring UWB sensor robust to body movement

A non-contact heartbeat monitoring sensor using stepped-FM ultra-wideband (UWB) scheme is suggested which is robust to body movement. The biological signal should be obtained from periodic chest movement consisting of the heartbeat and respiration. However, the heartbeat sensing suffers from body movement because of its smaller displacement relative to breathing motion. Therefore, a stationary subject is assumed for conventional heartbeat monitoring schemes. However, some displacement of a body should be presented during the measurement. This paper suggests a heartbeat estimation scheme with high accuracy for some body movement. The estimation performance has been experimentally evaluated for four subjects sitting on the stool using our fabricated sensor. It is found that our proposed system can be achieved with the estimation error less than 2%.