Classification of segmented phonocardiograms by convolutional neural networks

Abstract

One of the first causes of human deaths in recent years in our world is heart diseases or cardiovascular diseases. Phonocardiograms (PCG) and electrocardiograms (ECG) are usually used for the detection of heart diseases. Studies on cardiac signals focus especially on the classification of heart sounds. Naturally, researches generally try to increase accuracy of classification. For this purpose, many studies use for the segmentation of heart sounds into S1 and S2 segments by methods such as Shannon energy, discreet wavelet transform and Hilbert transform. In this study, two different heart sounds data in the PhysioNet Atraining data set such as normal, and abnormal are classified with convolutional neural networks. For this purpose, the S1 and S2 parts of the heart sounds were segmented by the resampled energy method. The images of Phonocardiograms which were obtained from S1 and S2 parts in the heart sounds were used for classification. The resized small images of phonocardiogram were classified by convolutional neural networks. The obtained results were compared with the results from previous studies. The classification with CNN has performance as classification accuracy of 97.21%, sensitivity of 94.78%, and specificity of 99.65%. According to this, CNN classification with segmented S1-S2 sounds showed better results than the results of previous studies. In studies carried out, it has been seen that segmentation and convolutional neural networks increases the accuracy of classification and contributes to the classification studies efficiently.