A Comparison of Cuff-less Blood Pressure Estimation Between Pulse Arrival Time and Pulse Transit Time Using Photoplethysmography

Abstract

Nowadays, there are various continuous cuffless methods to measure blood pressure (BP) and currently being interested in numerous researches. One intriguing approach is pulse arrival time (PAT) and pulse transit time (PTT) based technique. In this study, we aim to observe and compare the systolic blood pressure (SBP) prediction potential between PAT and PTT. PAT measurement was carried out using an electrocardiogram (ECG) and a finger photoplethysmogram (PPG). PTT was measured by the time interval between the peak of two-channel PPG, one placing above the elbow and another is at the index finger. Four volunteers were asked to perform a running exercise to raise the blood pressure, which causes PAT and PTT variation. The results show that PAT is closely related to SBP from three out of four subjects, giving MAD accuracy level < 7 mmHg according to IEEE std 1708™-2014. However, PTT shows a weak relationship with SBP. In conclusion, cuff-less PAT-based BP estimation shows a promise for clinical applications and could be used widely in the future with further developments.