The Auscultation of the heart sound is a most common method to obtain all the useful information to detect various diseases of cardiovascular system. However one of the main problems of PCG (phonocardiogram) signal analysis is interference of different sound. These sounds may be external or internal. The external sound is avoided by using sound proof room or other method etc. but internal sound like lung sound, vessel sound and muscle contraction sound is unavoidable during the recording of PCG signal. Wavelet is a most successful method for denoising the PCG signal. We have implemented a wavelet based denoising method for separation of lung sound from heart sound. In the wavelet transform (WT) based filter it has been shown that the multiresolution representation of the lung sound signal in the WT domain combined with soft-thresholding can separate the input signal (lung sound) from the nonstationary one (heart sound). The study investigates the different parameter of PCG signal before and after the wavelet based filtering. In this paper we separated the PCG signal from lung sound by different wavelets and found the wavelet which gives the appropriate PCG signal.
展开▼
