| This paper adopts wavelet to analyze the heart sound signal on the basis of the thing that discuss to the signal analytical method of the heart sound at present. It utilizes multi-resolution method of wavelet to decomposition and reconstruction heart sound signal, adopts Shannon information to carry on the amount of information to reconstruction signal of every level, and has confirmed localization level of the heart sound backbone. Then to utilize the method of Reimann sum it finishes the localization of the heart sound signal. After that, it carries on spectrum analyses to every level heart sound coefficient including cepstrum analysis, Hilbert spectrum analysis and energy spectrum analysis. It provides the characteristic of composition of heart sound, and offers reference for physiological pathological diagnosis of heart. In addition comparing with wavelet, this paper take the time-frequency method to analyze the heart sound signal also, and provides the qualitative analysis result.The cardiovascular disease is one of the diseases threatening the human health seriously. All the time, the doctor and project personnel pursue early diagnosis ability of cardiovascular disease. And the heart sound signal analyses are very useful in medical science. Heart sound signal is a compound sound of blood fluxion in heart systolic and diastole phase. It is a kind of basic method to appraise heart function state, and includes the physiology and pathology information of each part and interaction on in heart.The research of the heart sound signal has been a noticeable subject all the time. At heart sound analytical method, it has time analysis, frequently analysis, and the power spectrum analysis previously. And now it goes into the time-frequency analysis. The typical methods include STFT, auto-regression model and the wavelet in the time-frequency analysis of the heart sound. Then this paper adopts the wavelet to analyze heart sound signal and discusses the other methods to compare the signal analysis results.The main fields in heart sound study include the detection to artificial heart valve, the research of heart murmur like the third, fourth heart sound, etc., and the characteristic analysis of the first, second heart sound which also is the main field in heart sound study. This paper is mainly researching for characteristic of the first, second heart sound and the murmur of heart murmur in different pathology of situation.In specific analysis of this paper, at first to normalize signal to benefit the characteristic contrast. And then adopt Db4 wavelet to decompose and reconstruct the signal and analyze the interval and precision of Reimann sum to locate the signal. The second analyze the characteristics of heart sound signal in different pathology situation in each level wavelet spectrum. To use different analytical methods contrast result to provide different characteristics of the heart sound signal under different pathology situation and provide reference information for physiological pathological diagnosis of clinical heart. At last adopting STFT analyzes signal, providing the qualitative analysis result. Through to the development and wide application of modern digital signal processing technology and analysis of heart sound signal, the heart sound analysis will play a bigger role in clinical diagnosis and physiological basic research. |
PDF Full Text Request