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A system for heart sounds classification.

Redlarski G, Gradolewski D, Palkowski A - PLoS ONE (2014)

Bottom Line: The future of quick and efficient disease diagnosis lays in the development of reliable non-invasive methods.Thanks to the advancement in technology, the quality of phonocardiography signals is no longer an issue.The respective system is compared with four different major classification methods, proving its reliability.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechatronics and High Voltage Engineering, Gdansk University of Technology, Gdansk, Poland.

ABSTRACT
The future of quick and efficient disease diagnosis lays in the development of reliable non-invasive methods. As for the cardiac diseases - one of the major causes of death around the globe - a concept of an electronic stethoscope equipped with an automatic heart tone identification system appears to be the best solution. Thanks to the advancement in technology, the quality of phonocardiography signals is no longer an issue. However, appropriate algorithms for auto-diagnosis systems of heart diseases that could be capable of distinguishing most of known pathological states have not been yet developed. The main issue is non-stationary character of phonocardiography signals as well as a wide range of distinguishable pathological heart sounds. In this paper a new heart sound classification technique, which might find use in medical diagnostic systems, is presented. It is shown that by combining Linear Predictive Coding coefficients, used for future extraction, with a classifier built upon combining Support Vector Machine and Modified Cuckoo Search algorithm, an improvement in performance of the diagnostic system, in terms of accuracy, complexity and range of distinguishable heart sounds, can be made. The developed system achieved accuracy above 93% for all considered cases including simultaneous identification of twelve different heart sound classes. The respective system is compared with four different major classification methods, proving its reliability.

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Related in: MedlinePlus

Spectrum matching error for different filter orders.A comparison of matching errors in replicating a S3 heart tone spectrum. The presented curves indicate errors for three filters estimated by a Linear Predictive Coding algorithm with a transfer function of the 5th (red dotted line), 18th (green dotted line) and 24th (blue line) order. The 24th order filter obtained significantly lower error.
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pone-0112673-g004: Spectrum matching error for different filter orders.A comparison of matching errors in replicating a S3 heart tone spectrum. The presented curves indicate errors for three filters estimated by a Linear Predictive Coding algorithm with a transfer function of the 5th (red dotted line), 18th (green dotted line) and 24th (blue line) order. The 24th order filter obtained significantly lower error.

Mentions: To better illustrate the matching of individual filters, a comparison of their matching errors is shown in Figure 4. The error indicates the difference between a real PCG signal spectrum and a spectrum obtained from the estimated filter. It can be observed that the 5th and 18th order filters have a significantly higher error than the 24th order filter, which is especially visible at low frequencies. Above 100 Hz all filters have a negligible matching error. Additionally, in order to emphasize that the 24th order filter is better, a fitness factor for the above mentioned filters was calculated according to the following formula:(3)


A system for heart sounds classification.

Redlarski G, Gradolewski D, Palkowski A - PLoS ONE (2014)

Spectrum matching error for different filter orders.A comparison of matching errors in replicating a S3 heart tone spectrum. The presented curves indicate errors for three filters estimated by a Linear Predictive Coding algorithm with a transfer function of the 5th (red dotted line), 18th (green dotted line) and 24th (blue line) order. The 24th order filter obtained significantly lower error.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231067&req=5

pone-0112673-g004: Spectrum matching error for different filter orders.A comparison of matching errors in replicating a S3 heart tone spectrum. The presented curves indicate errors for three filters estimated by a Linear Predictive Coding algorithm with a transfer function of the 5th (red dotted line), 18th (green dotted line) and 24th (blue line) order. The 24th order filter obtained significantly lower error.
Mentions: To better illustrate the matching of individual filters, a comparison of their matching errors is shown in Figure 4. The error indicates the difference between a real PCG signal spectrum and a spectrum obtained from the estimated filter. It can be observed that the 5th and 18th order filters have a significantly higher error than the 24th order filter, which is especially visible at low frequencies. Above 100 Hz all filters have a negligible matching error. Additionally, in order to emphasize that the 24th order filter is better, a fitness factor for the above mentioned filters was calculated according to the following formula:(3)

Bottom Line: The future of quick and efficient disease diagnosis lays in the development of reliable non-invasive methods.Thanks to the advancement in technology, the quality of phonocardiography signals is no longer an issue.The respective system is compared with four different major classification methods, proving its reliability.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechatronics and High Voltage Engineering, Gdansk University of Technology, Gdansk, Poland.

ABSTRACT
The future of quick and efficient disease diagnosis lays in the development of reliable non-invasive methods. As for the cardiac diseases - one of the major causes of death around the globe - a concept of an electronic stethoscope equipped with an automatic heart tone identification system appears to be the best solution. Thanks to the advancement in technology, the quality of phonocardiography signals is no longer an issue. However, appropriate algorithms for auto-diagnosis systems of heart diseases that could be capable of distinguishing most of known pathological states have not been yet developed. The main issue is non-stationary character of phonocardiography signals as well as a wide range of distinguishable pathological heart sounds. In this paper a new heart sound classification technique, which might find use in medical diagnostic systems, is presented. It is shown that by combining Linear Predictive Coding coefficients, used for future extraction, with a classifier built upon combining Support Vector Machine and Modified Cuckoo Search algorithm, an improvement in performance of the diagnostic system, in terms of accuracy, complexity and range of distinguishable heart sounds, can be made. The developed system achieved accuracy above 93% for all considered cases including simultaneous identification of twelve different heart sound classes. The respective system is compared with four different major classification methods, proving its reliability.

Show MeSH
Related in: MedlinePlus