Signal processing and extensive characterization method of heart sounds based on wavelet analysis

One of the valuable methods of cardiac valve diagnosis can be performed by auscultation. We proposed a signal processing and extensive characterization method based on wavelet analysis to investigate important characteristics of heart sounds of normal and pathologic systolic murmur human subjects. Time-scale maps yielded by wavelet transform calculation were solved using magnitude thresholding operation and centre of gravity to restrict temporal and frequency-related of valvular activities. From our experimental results, temporal and frequencyrelated parameters of S₁, S₂, and their components could be characterized precisely. Application of our method was adequate to characterize the heart sounds objectively, clearly, systematically, and comprehensively. The method was considered valuable to explain mechanisms of cardiac valves functions. We expected that the method would be helpful for clinical diagnosis as well as developing of heart sound modelling and educational purpose. Next topic of our study was addressed for classification of the heart sounds.