Non-contact heart rate detection using periodic variation in Doppler frequency

Remote heart rate detection without body-attached probes is a promising technology for health care, monitoring of elderly people, emergency, and security. In this paper, we use a continuous wave (CW) microwave Doppler radar. It is important to eliminate the effect of body movement that is irrelevant to heartbeat such as respiration. In general, the displacements of them are larger than those of heartbeat. Therefore, we focus on the periodic variation of velocity of body movement due to heartbeat rather than the displacement variation of it. We detect a heart rate from a part of the wavelet frequency components with high periodicity. As a result of performance evaluation, our system enables to extract more accurate heartbeat interval than the traditional approach using the periodicity of an original Doppler signal.