New approach on analysis of pathologic cardiac murmurs based on WPD energy distribution

In this paper, an approach on analysis of the pathologic cardiac murmurs for congenital heart defects was proposed based on the wavelet packet (WP) technique. Considering the difference of the energy intensity distributions for the innocent and pathologic murmurs in frequency domain, the WP decomposition was introduced and the WP energies at each frequency band were calculated and compared. Based on the analysis of a large amount of clinic heart sound data, the murmurs energy distributions were divided into five frequency bands, and the relative evaluation indexes for cardiac murmurs (ICM) were proposed for analysis of the pathologic murmurs. Finally, the threshold values between the innocent and pathologic cardiac murmurs were determined based on the statistical results of the normal heart sounds. The analysis results validate the proposed evaluation indexes and the corresponding thresholds.