Development Of Non-contact Heart Rate Monitor Based On Piezoelectric Cable

With the continuous development of the economy and the ever-accelerating pace of life,the number of patients suffering from heart disease is increasing.The heart rate,as the most important physiological index of the human body,reflects the basic health status of the human cardiovascular system,so the long-term monitoring of the heart rate is the first step in heart disease prevention.In order to reduce the guardian's monitoring pressure and improve the heart rate measurement speed and accuracy,a non-contact heart rate monitoring system based on piezoelectric cables is designed and implemented in this paper.The heart rate measurement system developed in this paper solves the complexity of heart rate monitoring without letting the tester have any psychological influence.The wavelet transform is used to denoise the BCG signal collected by the system,and different wavelet functions and different decomposition scales are discussed for the difference of the signal denoising effect.Selecting the appropriate wavelet function decomposition scale greatly improves the accuracy of the heart rate signal extraction.The system also has a body motion detection function and a brainwave music module is designed to regulate the body's emotions.The comparison of the heart rate signal measurement of the system with the traditional method shows that the non-contact monitoring system has better real-time performance and reliability in the detection process.Experimental test results show that the overall average error of the heart rate detection of the monitor is less than ±4 beats/minute in the static state and the post-exercise state.The snake-shaped piezoelectric cable used in this design has a good shielding property and is relatively inexpensive and easy to be accepted by the masses in comparison with expensive piezoelectric films.In addition,the real-time wireless communication and data storage between the upper computer and the lower computer are achieved through Bluetooth,which makes the system display intuitive and convenient for users,and the wireless communication technology enables the measurement to be unrestrained to humans,which is in line with the development direction of the future heart rate signal monitoring.