Design Of Electronic Stethoscope Based On MEMS Acoustic Sensor

The incidence of cardiovascular disease in population is much higher,and shows a young trend,which is a serious threat to human life and health.Heart sound is an important index to reflect cardiac physiology and pathology,which is still the main diagnostic method of cardiovascular and cerebrovascular diseases.However,there are many shortcomings in the traditional stethoscope,and the diagnosis mainly depends on personal experience of doctor,which shows strong subjectivity.The auditory threshold of human ear is difficult to capture faint sensitive information,so the accuracy of diagnosis is relatively poor,which hinders the development of clinical medicine in heart sound auscultation.The electronic stethoscope on market can't be popularized because its high price.Therefore,the appearance of an electronic stethoscope with advantages of high sensitivity,good low frequency,direction and low cost is particularly urgent to overcome the shortcomings of the traditional stethoscope's insensitivity to heart sound and its inability to observe the waveform of heart sound.This electronic stethoscope can provide objective data for communication and teaching,and improve the accuracy of heart sound detection.In this paper,the background and significance of heart sound auscultation and the wide application of MEMS devices in the medical field are analyzed.Electronic stethoscope has the rapid development in China,but it is difficult to popularize because of its high cost.On the basis of summarizing the shortcomings of traditional heart sounds stethoscope and combining the excellent performance of MEMS devices,the design idea of heart sound electronic stethoscope based on MEMS acoustic sensor is put forward.In this paper,the design of the hardware system and software is described in detail.The hardware system includes heart sound probe,primary amplifier module,filter module,secondary amplifier module,main control module,power amplifier module and Bluetooth module.The design of each module is explained in detail.The software includes software flow chart,system initialization and Bluetooth initialization setting,and the key functions such as data acquisition and interruption processing are analyzed.Finally,the integrated system prototype is tested.Through the collection and display of human heart sound,the objective of visual and listening function is realized.The deficiencies in the system design and the contents to be improved are analyzed.