Development of a cardiorespiratory monitoring system based on pressure change of aircushion

Heartbeat and respiration are fundamental vital signs used for estimation of patient´s status. In this study, we have proposed a simple method to monitor the heartbeat and respiration based on displacements of human body which occur due to periodic heartbeat and breathing. The proposed system consists of an aircushion, pressure sensing hardware and extraction algorithm. The displacements of subject sitting on the aircushion are transferred to the aircushion and cause small pressure variations of the aircushion. To evaluate the proposed method, extracted respiration and heart rate from aircushion were compared with conventional method. The average sensitivity of respiration and heart rate are 96.66% and 98.27%, respectively. These results show the proposed method has advantages of installing and processing simplicity so as to be used easily in unconstrained respiration and heart rate monitoring in daily life.