Abstract
This paper proposes a functional assessment system of autonomic nervous system using an air pressure sensor. Heart rate variability is a recognized measure of autonomic nervous system. In general, heart rate variability is measured by an electrocardiograph. However, this method has to constrain human body to fix plural sensors directly in a surface of a body. The air pressure sensor can unconstraintly detect the vital information in bed by placing it to the under of the mattress. The proposal method detects heart rate variability with this system, and evaluates an autonomic nervous system. We employ a detection method of heartbeat point using fuzzy membership functions. The experimental results show that we detect RR intervals with the correlation coefficient of 0.851 with comparison to that of electrocardiograph. Then, the errors of the HF (index of parasympathetic system) and the LF/HF (index of sympathetic system) are 11.98% and 22.18%, respectively.
