Design Of Electronic Stethoscope Based On Bionic MEMS Heart Sound Sensor

Cardiovascular disease is known as the "number one killer" of human health,and heart sound,as an important physiological signal in the human body,contains a lot of physiological and pathological information related to the heart.it is one of the indispensable important bases for the research and diagnosis of cardiovascular diseases.In particular,a variety of heart diseases will show obvious signs of abnormal heart sounds in the early stage of disease or onset,for example,abnormal heart murmur will be shown physiologically when the early coronary artery occlusion rate of coronary heart disease reaches 25%.Therefore,heart sound signal has irreplaceable medical value for early prevention and diagnosis of cardiovascular disease.The premise of heart sound research is the acquisition of heart sound signals,that is,heart sound auscultation.In order to meet the needs of digital diagnosis and treatment of early prevention and diagnosis of cardiovascular disease,a MEMS heart sound sensor based on the sound pick-up mechanism of stereo ciliary bundles of bionic ear hair cells is designed in this paper.In this paper,the bionic MEMS heart sound sensor is theoretically studied and simulated,and on this basis,the structure of the MEMS heart sound sensor is designed and optimized,which improves the sensitivity(-196.7dB@500 Hz)and working bandwidth(20-600Hz)of the sensor.At the same time,an acoustic matching packaging method based on bionic MEMS heart sound sensor is designed,which reduces the sound loss of heart sound signal during auscultation and improves the signal-to-noise ratio(SNR=25.94dB)of electronic stethoscope.Secondly,the bionic MEMS heart sound sensor is applied to the field of heart sound auscultation,and an electronic stethoscope system based on bionic MEMS heart sound sensor is developed,which realizes the function of high sensitive detection and real-time display of heart sound signals.Finally,the collected heart sound signal is processed and analyzed,the signal characteristics of heart sound signal are studied and explored,and the rationality and feasibility of the designed MEMS electronic stethoscope for heart sound detection are verified.The electronic stethoscope based on bionic MEMS heart sound sensor designed in this paper has the advantages of high sensitivity,wide working frequency band,good low frequency characteristics,strong anti-interference ability,high signal-to-noise ratio,simple operation,heart sound visualization and so on.