An improved empirical mode decomposition-wavelet algorithm for phonocardiogram signal denoising and its application in the first and second heart sound extraction

In this paper, an improved EMD-Wavelet algorithm for PCG (Phonocardiogram) signal de-noising is proposed. Based on PCG signal processing theory, the S1/S2 components can be extracted by combining the improved EMD-Wavelet algorithm and Shannon energy envelope algorithm. By applying the wavelet transform algorithm and EMD (Empirical Mode Decomposition) for pre-procession, the PCG signal is well filtered. Based on the time frequency domain features of PCG´s IMF components which is extracted from the EMD algorithm and energy envelope of the PCG, the S1/S2 components are pinpointed accurately. Experiments of thirty samples illustrate the proposed algorithm, which reveals that the accuracy for recognition of S1/S2 components is as high as 99.74%.