The Design Of Heart Sound And ECG Data Collection System And Analysis Of Heart Sound

With the development of biomedical signal research,heart sound signal research has become the basis for the diagnosis of cardiovascular disease.The traditional diagnosis method for congenital heart disease is firstly diagnosed by a doctor through a stethoscope,and then diagnosed by echocardiography for cardiac color Doppler ultrasound.This type of diagnosis is difficult to diagnose in a remote area due to limited medical conditions and the ability of the primary doctor.In recent years,many screening and auscultation projects of congenital heart disease are organized all over the country by many charities and provincial hospitals in society.Doctors participating in screening usually have rich clinical experience.They will go to schools in rural,urban and remote villages.Cardiac auscultation was screened for congenital heart disease and then diagnosed using echocardiography.However,because there are too many people to check,and the number of doctors is small,it needs to travel around.If heart sounds are collected and digital analysis is carried out,the auxiliary diagnosis of congenital heart disease will help to improve the level of grassroots doctors.Patients with heart disease receive timely medical treatment.Therefore,designing a heart sound ECG acquisition system and studying the pathological information contained in the diagnosis of heart sound have important practical significance for the diagnosis of congenital heart disease.Firstly,this paper introduces the related knowledge about heart sound signal and the corresponding relationship between heart sound and ECG timing.Then,the portable heart sound and electrocardiogram acquisition system is designed based on it according to the basic characteristics of heart sound and electrocardiogram.The whole system is consisted of data acquisition of lower monitor and data processing of upper monitor.The lower monitor has signal acquisition and conversion by using STM32 chip to control AD7606 chip and then controls W5100 chip to upload the collected data to the upper monitor through UDP transmission protocol after packaging.The host computer software designed in C++ language unpacks the received data,draws a waveform graph and stores the data.Finally,this paper studies the heart sound signal and mainly study the time-frequency analysis of heart sound signal.First of all,have a pretreatment of the heart sound signal,and then have a time-frequency analysis on the heart sound signal after the pretreatment.The pretreatment is divided into three steps:denoising,envelope extraction and split fix.In this paper,three methods of time-frequency analysis are given and the experimental results of short-time Fourier transform,wavelet transform and S-transform of three methods are compared.Finally,three kinds of abnormal heart sound signals are analyzed by using S-transform time-frequency analysis method with better effect and obvious characteristic distribution time-frequency graphs are obtained.Therefore,the time-frequency feature vector can be extracted as the basis for classification and identification of congenital heart disease.