Adaptive noise reduction phonocardiograms based on wavelet transformation

The problem of adaptive reduction of noise of phonocardiograms (PCG) The problem of adaptive reduction of noise of phonocardiograms (PCG) based on wavelet transformation is considered in the article. Adaptive noise reduction is realized on the basis of the wavelet decomposition of the PCG using the Daubechies 4 wavelet function. The Daubechy 4 wavelet function is identical to the PCG patterns and well approximates the nonlinear local regions of the PCG. The proposed approach allows us to treat the PCG from physiological noise by high adaptively. The concept of decomposition is presented in the form of a set of filters that allow in automatic mode to remove noise by thinning twice at each stage of decomposition. On the basis of the obtained modeling results, the patterns of PCG, namely, mitral, pulmonary components of the PCG were identified.