Towards classifying non-segmented heart sound records using instantaneous frequency based features

Abstract

Heart sound and its recorded signal which is known as phonocardiograph (PCG) are one of the most important biosignals that can be used to diagnose cardiac diseases alongside electrocardiogram (ECG). Over the past few years, the use of PCG signals has become more widespread and researchers pay their attention to it and aim to provide an automated heart sound analysis and classification system that supports medical professionals in their decision. In this paper, a new method for heart sound features extraction for the classification of non-segmented signals using instantaneous frequency was proposed. The method has two major phases: the first phase is to estimate the instantaneous frequency of the recorded signal; the second phase is to extract a set of eleven features from the estimated instantaneous frequency. The method was tested into two different datasets, one for binary classification (Normal and Abnormal) and the other for multi-classification (Five Classes) to ensure the robustness of the extracted features. The overall accuracy, sensitivity, specificity, and precision for binary classification and multi-classification were all above 95% using both random forest and KNN classifiers.

Keywords:

• Heart sounds
• phonocardiogram (PCG)
• instantaneous frequency
• classification
• non-segmented PCG

Acknowledgments

The author would like to thank the PhysioNet and GitHub dataset providers for providing open access to heart sound classification datasets for both binary and multiclass cases. In addition, the author would like to thank the anonymous reviewers for their valuable comments.

Disclosure statement

No potential conflict of interest was reported by the author.