Improved computerized cardiac auscultation by discarding artifact contaminated PCG signal sub-sequence

Hearts sound signal recording through electronic stethoscope, also termed as phonocardiogram (PCG), is very sensitive to different kind of interferences. These interferences come as extra sounds which can appear at any instance of a heart sound cycle. A novice user may interpret these short duration interferences as a diseased marker. Also, for automated analysis of heart sound signal it is important to discard the artifact-affected signal sub-sequences. In this work, a novel method of detection of artifact in heart sound is presented. It uses a fusion of tunable Q-wavelet transform and signal second difference with median filter to detect the artifact-infected sub-sequences. The proposed method is compared with the discrete wavelet packet transform based method and quasi-periodicity based method used before. Performance of this technique is evaluated by considering most common occurring artifact types and at −5 dB, −3 dB and 0 dB SNRs. Four common types of pathological murmur sounds are considered in this experiment. An average accuracy of 96.13% is achieved for the proposed method which is superior to earlier published techniques.