2013 36th International Conference on Telecommunications and Signal Processing (TSP), 2013
ABSTRACT A mechanical heart valve is a device substituted for native heart valve. These valves ar... more ABSTRACT A mechanical heart valve is a device substituted for native heart valve. These valves are generally replaced with mitral or aorta valves. To found whether aorta or mitral heart valve replaced with mechanical one of patients is easy for specialist using stethoscope or chest X-ray. Expert system evaluating mechanical heart valve disease cannot deduce position of replaced heart valve. Thus, we aimed to determine which heart valve of patients was replaced with mechanical one to use preprocessing step in expert systems finding malfunctioning mechanical valve in this study. Electrocardiogram signal and 6 features extracted from power density of heart sounds were used to determine replaced heart valve using artificial neural networks. The heart sounds were separated into four parts according to recording area and sound component. Then, artificial neural networks was separately trained and tested for four sounds using the 6 features. As a result, the mechanical heart valve of patients was detected with 96.55% accuracy from the features of second heart sounds recorded from mitral area.
The aim of this study is to help to improve new diagnosis methods for cardiovascular disease by d... more The aim of this study is to help to improve new diagnosis methods for cardiovascular disease by designing a computer program and a hardware which realizes the recording of Korotkoff sounds produced during the measurement of blood pressure and basic analysis process. Korotkoff sounds have been traditionally used to measure blood pressure noninvasively by employing the auscultatory method. The recording system developed in this study can be used to produce a large database by recording some important information such as weight, age, and disease name in addition to Korotkoff sounds. Basic analysis processes like filtering and finding frequency component of recorded data is accomplished by means of the designed software. Thus, the necessity of using different computer programs for analyzing and recording data has been eliminated
Mechanical heart valves are a substitute for malfunctional native heart valves. In this study, th... more Mechanical heart valves are a substitute for malfunctional native heart valves. In this study, the spectral features of S1 and S2 component of the mechanical heart valve sounds obtained after aortic valve replacement (AVR) and mitral valve replacement (MVR) are compared. For this aim, AR methods are applied on the S1 and S2 components of heart sounds taken from 68 recording of 8 patients with AVR and 87 recordings from 11 patients with MVR, thereby yielding power spectrum of the heart sound and six different features are obtained from power spectrum of the heart sounds. Using these features, S1 and S2 components are compared.
Computer Methods in Biomechanics and Biomedical Engineering, 2012
In this article, the spectral features of first heart sounds (S1) and second heart sounds (S2), w... more In this article, the spectral features of first heart sounds (S1) and second heart sounds (S2), which comprise the mechanical heart valve sounds obtained after aortic valve replacement (AVR) and mitral valve replacement (MVR), are compared to find out the effect of mechanical heart valve replacement and recording area on S1 and S2. For this aim, the Welch method and the autoregressive (AR) method are applied on the S1 and S2 taken from 66 recordings of 8 patients with AVR and 98 recordings from 11 patients with MVR, thereby yielding power spectrum of the heart sounds. Three features relating to frequency of heart sounds and three features relating to energy of heart sounds are obtained. Results show that in comparison to natural heart valves, mechanical heart valves contain higher frequency components and energy, and energy and frequency components do not show common behaviour for either AVR or MVR depending on the recording areas. Aside from the frequency content and energy of the sound generated by mechanical heart valves being affected by the structure of the lungs–thorax and the recording areas, the pressure across the valve incurred during AVR or MVR is a significant factor in determining the frequency and energy levels of the valve sound produced. Though studies on native heart sounds as a non-invasive diagnostic method has been done for many years, it is observed that studies on mechanical heart valves sounds are limited. The results of this paper will contribute to other studies on using a non-invasive method for assessing the mechanical heart valve sounds.
Thrombosis of implanted heart valve is a rare but lethal complication for patients with mechanica... more Thrombosis of implanted heart valve is a rare but lethal complication for patients with mechanical heart valve. Echocardiogram of mechanical heart valves is necessary to diagnose valve thrombosis definitely. Because of the difficulty in making early diagnosis of thrombosis, and the cost of diagnosis equipment and operators, improving noninvasive, cheap and simple methods to evaluate the functionality of mechanical heart valves are quite significant especially for first step medical center. Because of this, time domain features obtained from auscultation of heart sounds are proposed to evaluate mechanical heart valve thrombosis as a simple method in this chapter. For this aim, heart sounds of one patient with mechanical heart valve thrombosis and five patients with normally functioning mechanical heart valve were recorded. Time domain features of recorded heart sounds, the skewness and kurtosis, were calculated and statistically evaluated using paired and unpaired t-test. As a result, it is clearly seen that the skewness of first heart sound is the most discriminative features (p < 0.01) and it may be used fairly well in differentiating normally functioning mechanical heart valve from malfunctioning mechanical heart valve.
2013 36th International Conference on Telecommunications and Signal Processing (TSP), 2013
ABSTRACT A mechanical heart valve is a device substituted for native heart valve. These valves ar... more ABSTRACT A mechanical heart valve is a device substituted for native heart valve. These valves are generally replaced with mitral or aorta valves. To found whether aorta or mitral heart valve replaced with mechanical one of patients is easy for specialist using stethoscope or chest X-ray. Expert system evaluating mechanical heart valve disease cannot deduce position of replaced heart valve. Thus, we aimed to determine which heart valve of patients was replaced with mechanical one to use preprocessing step in expert systems finding malfunctioning mechanical valve in this study. Electrocardiogram signal and 6 features extracted from power density of heart sounds were used to determine replaced heart valve using artificial neural networks. The heart sounds were separated into four parts according to recording area and sound component. Then, artificial neural networks was separately trained and tested for four sounds using the 6 features. As a result, the mechanical heart valve of patients was detected with 96.55% accuracy from the features of second heart sounds recorded from mitral area.
The aim of this study is to help to improve new diagnosis methods for cardiovascular disease by d... more The aim of this study is to help to improve new diagnosis methods for cardiovascular disease by designing a computer program and a hardware which realizes the recording of Korotkoff sounds produced during the measurement of blood pressure and basic analysis process. Korotkoff sounds have been traditionally used to measure blood pressure noninvasively by employing the auscultatory method. The recording system developed in this study can be used to produce a large database by recording some important information such as weight, age, and disease name in addition to Korotkoff sounds. Basic analysis processes like filtering and finding frequency component of recorded data is accomplished by means of the designed software. Thus, the necessity of using different computer programs for analyzing and recording data has been eliminated
Mechanical heart valves are a substitute for malfunctional native heart valves. In this study, th... more Mechanical heart valves are a substitute for malfunctional native heart valves. In this study, the spectral features of S1 and S2 component of the mechanical heart valve sounds obtained after aortic valve replacement (AVR) and mitral valve replacement (MVR) are compared. For this aim, AR methods are applied on the S1 and S2 components of heart sounds taken from 68 recording of 8 patients with AVR and 87 recordings from 11 patients with MVR, thereby yielding power spectrum of the heart sound and six different features are obtained from power spectrum of the heart sounds. Using these features, S1 and S2 components are compared.
Computer Methods in Biomechanics and Biomedical Engineering, 2012
In this article, the spectral features of first heart sounds (S1) and second heart sounds (S2), w... more In this article, the spectral features of first heart sounds (S1) and second heart sounds (S2), which comprise the mechanical heart valve sounds obtained after aortic valve replacement (AVR) and mitral valve replacement (MVR), are compared to find out the effect of mechanical heart valve replacement and recording area on S1 and S2. For this aim, the Welch method and the autoregressive (AR) method are applied on the S1 and S2 taken from 66 recordings of 8 patients with AVR and 98 recordings from 11 patients with MVR, thereby yielding power spectrum of the heart sounds. Three features relating to frequency of heart sounds and three features relating to energy of heart sounds are obtained. Results show that in comparison to natural heart valves, mechanical heart valves contain higher frequency components and energy, and energy and frequency components do not show common behaviour for either AVR or MVR depending on the recording areas. Aside from the frequency content and energy of the sound generated by mechanical heart valves being affected by the structure of the lungs–thorax and the recording areas, the pressure across the valve incurred during AVR or MVR is a significant factor in determining the frequency and energy levels of the valve sound produced. Though studies on native heart sounds as a non-invasive diagnostic method has been done for many years, it is observed that studies on mechanical heart valves sounds are limited. The results of this paper will contribute to other studies on using a non-invasive method for assessing the mechanical heart valve sounds.
Thrombosis of implanted heart valve is a rare but lethal complication for patients with mechanica... more Thrombosis of implanted heart valve is a rare but lethal complication for patients with mechanical heart valve. Echocardiogram of mechanical heart valves is necessary to diagnose valve thrombosis definitely. Because of the difficulty in making early diagnosis of thrombosis, and the cost of diagnosis equipment and operators, improving noninvasive, cheap and simple methods to evaluate the functionality of mechanical heart valves are quite significant especially for first step medical center. Because of this, time domain features obtained from auscultation of heart sounds are proposed to evaluate mechanical heart valve thrombosis as a simple method in this chapter. For this aim, heart sounds of one patient with mechanical heart valve thrombosis and five patients with normally functioning mechanical heart valve were recorded. Time domain features of recorded heart sounds, the skewness and kurtosis, were calculated and statistically evaluated using paired and unpaired t-test. As a result, it is clearly seen that the skewness of first heart sound is the most discriminative features (p < 0.01) and it may be used fairly well in differentiating normally functioning mechanical heart valve from malfunctioning mechanical heart valve.
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