Fingertip Pulse Wave Detection and Analysis Based on PVDF Piezoelectric Thin Film Sensor

The pulse wave contains very rich cardiovascular physiological and pathological information, its waveform amplitude and shape can reflect the physiological and pathological state of human cardiovascular system such as heart rate and blood pressure. Monitoring of pulse wave has important clinical diagnostic value in traditional Chinese medicine and modern medicine. However, the characteristics of weak pulse signal and vulnerable to interference make the extraction of useful fingertip pulse signals a difficult task. Here we propose a type of sensor based on polyvinylidene fluoride (PVDF) piezoelectric thin film that can collect fingertip pulse signal; By zero-phase filtering and de-noising, the baseline wander and interference in fingertip pulse signal can be successfully eliminated; In order to verify the validity, practicality of the fingertip pulse signal, the pulse signal with the fingertip is compared with those obtained with the wrist artery, and the characteristics of these two pulse signals are finally further analyzed in time domain and frequency domain. It is shown that the proposed piezoelectric film sensor can effectively detect the pulse fingertip signal. It is also shown the fingertip pulse signal amplitude is smaller than those obtained with the radial artery, but the measured pulse number in unit time with the fingertip is consistent with the radial artery measured result. From the analysis in frequency domain, the pulse fingertip signal focus on the low frequency component, and contains the main physiological information of human body, it is also more convenient access than the radial artery signal.