Abstract
In this study, a body motion compensation method for blood pressure measurement using a pulse wave velocity (PWV) method is proposed. PWV method has advantages to provide continuous systolic blood pressure from pulse transit time (PTT), and to avoid an excessive burden caused by cuff used in conventional sphygmomanometers. However, the measurement accuracy of PTT is heavily reduced by body motion. In order to solve this problem, a body motion compensation filter is needed. To design the motion compensation filter, we made experiments using a motion simulator for grasping the relationship between body motion and its influence on pulse wave (body motion component). As a result, it became clear that body motion component is proportional to body motion acceleration, but its proportionality coefficients are different among subjects. It also became clear that the frequency of body motion component is equal to the frequency of body motion acceleration. Based on these results, we propose a body motion compensation filter, which could cancel the body motion components being estimated from the above-mentioned experiment. By applying this filter to the data of motion simulator experiments, the variance of PTT was decreased to 50%. In addition, by applying to the data of walking experiments, the variance of PTT was decreased to 65%.
