Comparison between Short time Fourier and Wavelet Transform for Feature Extraction of Heart sount

초록

This paper presents the application of the wavelet transform analysis method to the phoncardiogram(PCG) signal. Heart sound is a highly nonstationary signal. So in the anaysis of heart sound, it is important to study the frequency and time information. To investigate the exact features of heart sound, we adopt Short-Time Fourier Transform(STFT) and Wavelet Transform(WT) as time-frequency representation. As a result, it is found that the STFT analysis cannot detect the four components of the first sound in the PCG signal and the two components of the second sound are inacurately detected. On the other hand, It is found that the wavelet transform is capable of detecting the two components the aortic valve component A2 and pulmonary valve component P2, of the second sound S2 in a normal PCG signal. Furthermore, wavelet transform provides more features and characteristics of the PCG signals that will help physician to obtain qualitative and quatitative measurements of the heart sound.