Research On The Electronic Auscultation System Based Android

At present,auscultation is still an important medical method for the diagnosis of cardiovascular and respiratory diseases.Although the traditional mechanical stethoscope is widely used in clinical diagnosis because of its simple operation and low cost,it is easy to ignore some important pathological murmurs by using the traditional mechanical stethoscope because of the weak signal of cardiopulmonary sound.The results of auscultation are influenced by the subjective factors of doctors.In order to remedy the defects of traditional mechanical auscultation,it is of certain practical value to study electronic auscultation system combined with digital signal processing technology.The popularity of smart phones with Android also lays a good foundation for combing electronic stethoscope with the mobile terminal.In view of this,this paper studies the electronic auscultation system based on Android platform.The aim is to improve the stethoscope performance of electronic stethoscope through the development of cardiopulmonary sound sensor and the use of environmental noise resistance technology,The combination of electronic stethoscope and the mobile terminal can not only reduce the cost,but also increase portability,thus,promoting the clinical application of electronic auscultation system.The main work of this paper is as follows: Firstly,the piezoelectric sensor with PZT-5 dual-diaphragm structure is determined to be used by analyzing the existing structure of piezoelectric material and piezoelectric sensor.Then based on the finite element analysis method of ANSYS,the simulation analysis of piezoelectric sensor will be completed,and the relationship between the structure size,output voltage and natural frequency of piezoelectric sensor will be obtained.According to the simulation results,the piezoelectric sensor will be customized and the sensor measurement circuit and cavity structure will be designed to complete the development of the cardiopulmonary sound piezoelectric sensor.Secondly,through the signal-to-noise ratio and spectrum chart of LMS,NLMS and RLS the three adaptive filtering algorithms to evaluate cardiopulmonary sound noise reduction effect,this thesis can get the best filtering effect of RLS.The electronic stethoscope is designed,and the functions of real-time auscultation,volume adjustment and auscultation mode selection are realized combined with the adaptive spectral line enhancement technology based on RLS algorithm.Thirdly,the application software design is completed based on Android platform,which receives the cardiopulmonary sound data through the headphone interface of the smartphone,and realizes the functions of real-time auscultation,waveform display,recording storage,intelligent analysis,cardiopulmonary sound management,report generation and sharing.Finally,electronic stethoscope and the effectiveness of the whole system are tested.The test results show that the hardware realizes the basic functions of real-time auscultation,volume adjustment and auscultation mode selection.and The data of the hardware side and application software can be transmitted in real time,and the mobile end can record and display waveform while listening.The system has the advantages of low cost,high portability and strong practicability.It is suitable for hospitals,families,teaching and other occasions and beneficial to the popularization and application of electronic auscultation system.