title: High Order Statistics and Time-Frequency Domain to Classify Heart Sounds for Subjects under Cardiac Stress Test.
abstract: This paper considers the problem of classification of the first and the second heart sounds (S1 and S2) under cardiac stress test. The main objective is to classify these sounds without electrocardiogram (ECG) reference and without taking into consideration the systolic and the diastolic time intervals criterion which can become problematic and useless in several real life settings as severe tachycardia and tachyarrhythmia or in the case of subjects being under cardiac stress activity. First, the heart sounds are segmented by using a modified time-frequency based envelope. Then, to distinguish between the first and the second heart sounds, new features, named α(opt), β, and γ, based on high order statistics and energy concentration measures of the Stockwell transform (S-transform) are proposed in this study. A study of the variation of the high frequency content of S1 and S2 over the HR (heart rate) is also discussed. The proposed features are validated on a database that contains 2636 S1 and S2 sounds corresponding to 62 heart signals and 8 subjects under cardiac stress test collected from healthy subjects. Results and comparisons with existing methods in the literature show a large superiority for our proposed features.
authors.affiliation: MIPS Laboratory, University of Haute Alsace, 68093 Mulhouse, France.
authors.forename: Ali
authors.initials: A
authors.lastname: Moukadem
authors.affiliation: Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark.
authors.forename: Samuel
authors.initials: S
authors.lastname: Schmidt
authors.affiliation: MIPS Laboratory, University of Haute Alsace, 68093 Mulhouse, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Dieterlen
mesh_terms: D000328:Adult; D019295:Computational Biology; D003971:Diastole; D004562:Electrocardiography / Q000706:statistics & numerical data; D005080:Exercise Test / Q000706:statistics & numerical data*; D005260:Female; D006326:Heart Auscultation / Q000706:statistics & numerical data; D006339:Heart Rate; D006347:Heart Sounds / Q000502:physiology*; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D015233:Models, Statistical; D010701:Phonocardiography / Q000706:statistics & numerical data; D012016:Reference Values; D013599:Systole; D013997:Time Factors; D055815:Young Adult