Heart Rate Detection With Hilbert Vibration Decomposition in Random Body Movements Based on FMCW Radars

An enhanced Hilbert vibration decomposition (HVD) algorithm is proposed to mitigate nonstationary vibration signals. Heart rates can be detected under large-scale random body movement (RBM) conditions by using the proposed HVD method for frequency-modulated continuous wave (FMCW) radars. In noncontact measurement, the presence of RBM can seriously interfere with the extraction of vital signs. In comparison with empirical mode decomposition (EMD) as one of the effective traditional solutions, HVD has a higher frequency resolution capacity and can resolve considerably closer frequencies. For this situation, HVD effectively separates large-scale RBM from vital signs first. Then, masking signal HVD (M-HVD) effectively reduces the error rate of heartbeat. The average relative error is 1.64%, and the signal-to-noise ratio is improved by 8.3 dB in comparison to Empirical Wavelet Transform (EWT) and EMD.