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The aim of this study is to present a complexity measure (Normalized Shannon Entropy) based on the S-Transform Spectrogram (ST-Spectrogram) plane, which can be considered as a variant of the Cohen's class. The ST-Spectrogram verifies the non-negativity condition which makes the application of the famous Shannon Entropy measure possible. A concrete… (More)
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… (More)
In this exploratory study we propose to analyze, in healthy adult volunteers, the heart electrical (electrocar-diogram, ECG) and mechanical (phonocardiogram, PCG) activity during exercise. Heart sounds amplitude, frequency content, and RS2, may be important features in the non-invasive assessment of heart activity, such as for the estimation of cardiac… (More)
The aim of this paper is to improve the energy concentration of the Stockwell transform (S-transform) in the time-frequency domain. Several methods proposed in the literature tried to introduce novel parameters to control the width of the Gaussian window in the S-transform. In this study, a modified S-transform is proposed with four parameters to control… (More)
This paper presents a novel method for QRS detection in electrocardiograms (ECG). It is based on the S-Transform, a new time frequency representation (TFR). The S-Transform provides frequency-dependent resolution while maintaining a direct relationship with the Fourier spectrum. We exploit the advantages of the S-Transform to isolate the QRS complexes in… (More)