System modeling and signal processing of microwave Doppler radar for cardiopulmonary sensing

In this paper, we present the modeling, simulation and signal processing of Doppler radar for heart beat and reparation sensing. Distance dependency of accuracy of heart and respiration signal from radar output is investigated and verified through simulation. The model is experimentally validated with commercially available motion detector DNO-341. The based band signal containing respiration and heartbeat signatures are low-pass filtered (0.7 Hz) for the respiration and band-pass filtered (0.9-2.5 Hz) for the heart signal. The estimated heart beat per minute and peak-peak interval is verified with result obtained from standard ECG measurement.