Individual-Based Cuffless Continue Estimation of Blood Pressure Measurement: Using Multiple Pulse Transmit Time

A noninvasive continue measurement of blood pressure(BP) is of great significance for indicating the status cardiovascular system and evaluating circulatory function in homecare monitoring. Pulse transit time(PTT) is one of the most popular indicator for cuffless systolic BP(SBP) and diastolic BP(DBP) measurement. However, different PTT definitions have been used in relative researches and no comparative study reported which was the most reliable one. Moreover, an indivudal-based method is necessary because value of specific parameters differ from person to person due to their corporeity. In this study, an individual based PTT-BP calibration method was proposed, taking three PTT definition into consideration to effectively avoid the sharp deviation of blood pressure caused by single PTT measurement. Model was innovatively trained with back-propagation method and evaluated with five-fold cross validation. Results verified parameters in our PTT-BP model were different in individuals and showed our calibration method was valid. Correlation coefficients for SBP and DBP with the reference BP in our model were 0.9634 and 0.9740 respectively, and mean absolute deviation(MAD) were 2.83 and 2.82 mmHg, which indicates a more stable estimation in a large dataset.