Segmentation and classification of heart sounds

An algorithm for segmentation of heart sounds (HSs) into a single cardiac cycle (S 1-Systole-S 2-Diastole) using homomorphic filtering and k-means clustering and a three way classification of heart sounds into Normal (N), Systolic murmur (S), and Diastolic murmur (D), based on neural networks is developed. This algorithm does not require additional reference signal such as ECG signal. Feature vectors are formed after segmentation by using Daubechies-2 wavelet detail coefficients at the second decomposition level. Redundant features are removed using principal component analysis (PCA). Multilayer perceptron-Backpropagation neural network (MLP-BP) is used for classification of three different HSs. A classification accuracy of 94.5% and a segmentation accuracy (or performance) of 90.45% was achieved; thus, demonstrating that segmentation and classification of heart sounds without the aid of reference signal is achievable.