Preliminary study in the analysis of the severity of cardiac pathologies using the higher-order spectra on the heart-beats signals

Abstract Phonocardiography is a technique for recording and interpreting the mechanical activity of the heart. The recordings generated by such a technique are called phonocardiograms (PCG). The PCG signals are acoustic waves revealing a wealth of clinical information about cardiac health. They enable doctors to better understand heart sounds when presented visually. Hence, multiple approaches have been proposed to analyze heart sounds based on PCG recordings. Due to the complexity and the high nonlinear nature of these signals, a computer-aided technique based on higher-order statistics (HOS) is employed, it is known to be an important tool since it takes into account the non-linearity of the PCG signals. This method also known as the bispectrum technique, can provide significant information to enhance the diagnosis for an accurate and objective interpretation of heart condition. The objective expected by this paper is to test in a preliminary way the parameters which can make it possible to establish a discrimination between the various signals of different pathologies and to characterize the cardiac abnormalities. This preliminary study will be done on a reduced sample (nine signals) before applying it subsequently to a larger sample. This work examines the effectiveness of using the bispectrum technique in the analysis of the pathological severity of different PCG signals. The presented approach showed that HOS technique has a good potential for pathological discrimination of various PCG signals.

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Induction machine condition monitoring with higher order spectra

IEEE Transactions on Industrial Electronics ◽

10.1109/41.873211 ◽

2000 ◽

Vol 47 (5) ◽

pp. 1031-1041 ◽

Cited By ~ 121

Author(s):

N. Arthur ◽

J. Penman

Keyword(s):

Condition Monitoring ◽

Induction Machine ◽

Higher Order ◽

Machine Condition ◽

Machine Condition Monitoring ◽

Higher Order Spectra

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Detection and localization of S1 and S2 heart sounds by 3rd order normalized average Shannon energy envelope algorithm

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411921998108 ◽

2021 ◽

pp. 095441192199810

Author(s):

Madhwendra Nath ◽

Subodh Srivastava ◽

Niharika Kulshrestha ◽

Dilbag Singh

Keyword(s):

Success Rate ◽

Heart Sound ◽

Heart Diseases ◽

Heart Sounds ◽

Sound Signal ◽

Ecg Signal ◽

Shannon Energy ◽

Detection And Localization ◽

Pcg Signals ◽

Heart Sound Signal

Adults born after 1970s are more prone to cardiovascular diseases. Death rate percentage is quite high due to heart related diseases. Therefore, there is necessity to enquire the problem or detection of heart diseases earlier for their proper treatment. As, Valvular heart disease, that is, stenosis and regurgitation of heart valve, are also a major cause of heart failure; which can be diagnosed at early-stage by detection and analysis of heart sound signal, that is, HS signal. In this proposed work, an attempt has been made to detect and localize the major heart sounds, that is, S1 and S2. The work in this article consists of three parts. Firstly, self-acquisition of Phonocardiogram (PCG) and Electrocardiogram (ECG) signal through a self-assembled, data-acquisition set-up. The Phonocardiogram (PCG) signal is acquired from all the four auscultation areas, that is, Aortic, Pulmonic, Tricuspid and Mitral on human chest, using electronic stethoscope. Secondly, the major heart sounds, that is, S1 and S2are detected using 3rd Order Normalized Average Shannon energy Envelope (3rd Order NASE) Algorithm. Further, an auto-thresholding has been used to localize time gates of S1 and S2 and that of R-peaks of simultaneously recorded ECG signal. In third part; the successful detection rate of S1 and S2, from self-acquired PCG signals is computed and compared. A total of 280 samples from same subjects as well as from different subjects (of age group 15–30 years) have been taken in which 70 samples are taken from each auscultation area of human chest. Moreover, simultaneous recording of ECG has also been performed. It was analyzed and observed that detection and localization of S1 and S2 found 74% successful for the self-acquired heart sound signal, if the heart sound data is recorded from pulmonic position of Human chest. The success rate could be much higher, if standard data base of heart sound signal would be used for the same analysis method. The, remaining three auscultations areas, that is, Aortic, Tricuspid, and Mitral have smaller success rate of detection of S1 and S2 from self-acquired PCG signals. So, this work justifies that the Pulmonic position of heart is most suitable auscultation area for acquiring PCG signal for detection and localization of S1 and S2 much accurately and for analysis purpose.

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Detection of subthalamic nucleus using novel higher-order spectra features in microelectrode recordings signals

Journal of Applied Biomedicine ◽

10.1016/j.bbe.2021.04.016 ◽

2021 ◽

Author(s):

Mohamed Hosny ◽

Minwei Zhu ◽

Wenpeng Gao ◽

Yili Fu

Keyword(s):

Subthalamic Nucleus ◽

Higher Order ◽

Microelectrode Recordings ◽

Higher Order Spectra

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Comparing Primary Voice-Hearers with and without Hallucinations in Other Sensory Modalities

Psychopathology ◽

10.1159/000517455 ◽

2021 ◽

pp. 214-220

Author(s):

Wei Lin Toh ◽

Neil Thomas ◽

Susan L. Rossell

Keyword(s):

Functional Impairment ◽

Auditory Hallucination ◽

Sensory Modality ◽

Clinical Information ◽

Auditory Hallucinations ◽

Auditory Modality ◽

Positive Symptoms ◽

Psychotic Experiences ◽

Sensory Modalities ◽

Preliminary Study

There has been burgeoning interest in studying hallucinations in psychosis occurring across multiple sensory modalities. The current study aimed to characterize the auditory hallucination and delusion profiles in patients with auditory hallucinations only versus those with multisensory hallucinations. Participants with psychosis were partitioned into groups with voices only (AVH; <i>n</i> = 50) versus voices plus hallucinations in at least one other sensory modality (AVH+; <i>n</i> = 50), based on their responses on the Scale for the Assessment of Positive Symptoms (SAPS). Basic demographic and clinical information was collected, and the Questionnaire for Psychotic Experiences (QPE) was used to assess psychosis phenomenology. Relative to the AVH group, greater compliance to perceived commands, auditory illusions, and sensed presences was significantly elevated in the AVH+ group. The latter group also had greater levels of delusion-related distress and functional impairment and was more likely to endorse delusions of reference and misidentification. This preliminary study uncovered important phenomenological differences in those with multisensory hallucinations. Future hallucination research extending beyond the auditory modality is needed.

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