Heart Disease Diagnosis Research Based On Time-frequency Distribution Heart Sound Signal Analysis

Heart sound consists a large number of physiological and pathological information as one of the important human physiological signals, it is helpful for heart disease diagnosis and treatment in depth analysis to the heart sound. Domestic and foreign scholars do a lot of researches on the heart sound signasl in view of the role that heart sound plays in heart disease diagnosis. However, due to the constraint of signal acquisition and signal processing technology,the diagnostic results of heart disease is not very good.This paper carried out in-depth study for the main problems that heart sound signal acquisition and heart disease diagnosis exists. Analyze characteristic of the main composition of heart sound signals in time domain and frequency domain from the heart sounds signal generation principle and analyze different types of heart sound signals in cardiac systolic or diastolic happen moments, point out these study has important guiding significance in heart sound signal acquisition and heart disease diagnosis; With the LabVIEW8.6 development platform achieves the heart sound signal acquisition using home-made heart sound signal acquisition system. Carries out the heart sound signals filtering and denoising by the method of wavelet denoising, we select coif5 wavelet function for it is symmetric completely and combined multi-level thresholding denoising, the effect is obvious; Gives the time-frequency spectrum comparison analysis to normal heart sound signals and mitral stenosis and pulmonary stenosis heart sound signals selecting Wigner-Ville Distribution, Choi-Williams Distribution and the Cone-Shape Distribution and gets the change process that heart sound signals frequency components over time; Conducts on the energy spectrum analysis to the normal and abnormal heart sound signals through the method of Instantaneous frequency analysis, highlight the local characteristics of heart sound signals, reveals the change process that heart sound signals frequency components over time, provides a direct and effective analysis method for clinical diagnosis.Either from the time domain or frequency domain energy spectrum,we can distinct mitral stenosis and pulmonary stenosis heart sounds from normal heart sounds intuitively and effectively through the two methods. Achieves the distinction diagnosis of common heart valve disease, has some clinical value.