Vital signs modeling for Doppler radar cardiorespiratory monitoring

Microwave Doppler radar system is utilized to sense breathing and heartbeat of human beings to monitor their vital conditions. The Doppler radar not only receives vital sign signals but also acquires different additive and unwanted waves such as the signal of the extra motion of the body, clutter and electromagnetic noise. Making a mathematical model of received signal by a Doppler radar will be helpful to analyze vital conditions. In this paper we simulated the signal received by a Doppler radar system, and the results were compared with the vital signals obtained from a human by both a custom designed 24 GHz radar and a commercial respiratory transducer attached around the chest; in both time and frequency domains.