Low-power digital-IF noncontact instantaneous vital sign detection based on synchrosqueezing transform

Aiming at detecting the instantaneous vital sign frequencies, which are very important to the clinical diagnosis and treatment, a novel method based on synchrosqueezing transform (SST) is applied to the low-power digital-IF non-contact vital sign detection system. The proposed technique reallocates the coefficients resulting from a wavelet transform to get a concentrated picture over the time-frequency plane, from which the instantaneous frequencies can be extracted. Through experiment and direct comparison with contact sensors, the instantaneous respiratory and heartbeat frequencies can be accurately obtained by the proposed method.