Noncontact heart beat signal extraction based on wavelet transform

Noncontact monitoring of vital signs by continuous wave Doppler radar is a promising technique in the field of health care. This paper proposed an improved heart beat signal extraction method based on wavelet transform for noncontact radar vital signal monitoring. The detection accuracy of heart beat rate by the proposed method was higher than bandpass filtering and empirical mode decomposition (EMD) method (all p<0.05) and the bandpass filtering method at different distances. Detection accuracy and signal to noise ratio varied inversely to distance. Male subjects in front case and female subjects in back case acquired higher accuracy than other orientations.