A New Type of Bionics Based Piezoelectric Heartbeat Sensor Used in Pulse-Taking for Health Warning

This work demonstrates a novel bionics-based heartbeat sensor combined with approximate entropy (ApEn) algorithm for health warning. The design of the proposed sensor was inspired by pulse-taking therapy in traditional Chinese medicine (TCM). A flexible piezoelectric film was adhered to a wooden cylinder to simulate the structure of the finger to achieve pulse-taking. The simulation of piezoelectric film under different force area and bending degree was realized by ANSYS. The results showed that the sensor structure proposed in this paper can not only simulate the characteristics of the finger to achieve the TCM pulse-taking, but also improve the sensitivity of piezoelectric film. The sensor was used to measure the pulse signal of human under different states of motion and different health conditions. Then the sample data were analyzed using the ApEn. The results showed that the ApEn value is 0.1 can be used as a threshold for judging and predicting human health status. The experiment proved that this method can avoid the requirement of the same force in the traditional pulse-taking. It not only can obtain the low distortion pulse signal, but also can obtain the heart rate accurately. Using this method can quickly achieve rapid detection and early warning of human health.