A portable multi-physiological signal synchronization acquisition device for cuff-less blood pressure variation tracking

Blood pressure (BP) is a vital physiological parameter of the human body. Currently, BP measurement needs to be portable and comfortable. Thus, cuff-less BP measurement is becoming more and more crucial. This paper proposes a portable multi-physiological signal synchronization acquisition device for cuff-less BP variation tracking. The analog front-end circuit is designed to record in Electrocardiogram (ECG), Photoplethysmogram (PPG), and Phonocardiogram (PCG). The effects of the pre-ejection period (PEP) can be reduced using PPG and PCG signals. After that, an artificially induced BP variation experiment is designed, and data is collected from 10 subjects to confirm the reliability of this device. Three pulse transit time indexes (PTT, PTTD, PTTV) is calculated from the PPG and PCG features. Finally, the Pearson correlation coefficients between the reference BP and three PTTs are calculated. The results show that PTTD had the highest correlation with SBP (−0.869 ± 0.153), and PTT had the highest correlation with DBP (−0.737 ± 0.117). Therefore, this device is feasible for tracking BP variations by a cuff-less method.