The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound sign...The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound signals were denoised by using wavelet filters,the signals were applied bicoherence analysis that is an high order spectral analysis method.It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values.展开更多
According to the definition of correlation dimension in fractal theory, this paper presented a method to determine and assess noise part in detected transient signal. Such work is essential to decrease the noise part ...According to the definition of correlation dimension in fractal theory, this paper presented a method to determine and assess noise part in detected transient signal. Such work is essential to decrease the noise part in the detected signal. It is proved that heart period signal (HPS) is one typical sort of transient chaotic signal. Through experiment and simulation, the analysis of chaotic HPS in the detected signal was done. In the end, we deepen the researches on attractor dimension of HPS for persons who are different in age.展开更多
The aim of this study was to develop a method for predicting the psychological states of spectators watching professional baseball games at a stadium. This method includes a real time measurement of instantaneous hear...The aim of this study was to develop a method for predicting the psychological states of spectators watching professional baseball games at a stadium. This method includes a real time measurement of instantaneous heart rate (i.e., the inverse of the RR interval) without preventing the subject from watching the game and a mathematical procedure used to predict moment by moment psychological states by correlating the degree of a psychological state with the strength of heart rate response, defined as the mean deviation of heart rate variability from a linear regression line from 5 sec before to 25 sec after an event during a baseball game. We recorded the instantaneous heart rates of 10 subjects (total of 27 cases) while they watched Japanese professional baseball games at a stadium and had them subjectively rate the degree of their psychological states in an after-event interview. We identified three psychological states (happiness, excitement, and vigor) whose strength can be predicted from the strength of heart rate response. Analysis of the measured data clarified that heart rate response had a significant correlation with the subjective rating of the intensity of happiness (r = 0.56, p < 0.0001), vigor (r = 0.55, p < 0.0001), and excitement (r = 0.49, p < 0.0001).展开更多
Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate v...Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate variability signal through the classical and time-frequency methods. At first, one minute of ECG signals, just before the cardiac death event are extracted and used to compute heart rate variability (HRV) signal. Five features in time domain and four features in frequency domain are extracted from the HRV signal and used as classical linear features. Then the Wigner Ville transform is applied to the HRV signal, and 11 extra features in the time-frequency (TF) domain are obtained. In order to improve the performance of classification, the principal component analysis (PCA) is applied to the obtained features vector. Finally a neural network classifier is applied to the reduced features. The obtained results show that the TF method can classify normal and SCD subjects, more efficiently than the classical methods. A MIT-BIH ECG database was used to evaluate the proposed method. The proposed method was implemented using MLP classifier and had 74.36% and 99.16% correct detection rate (accuracy) for classical features and TF method, respectively. Also, the accuracy of the KNN classifier were 73.87% and 96.04%.展开更多
The two ubiquitous, outside the retina, G protein-coupled receptor(GPCR)adapter proteins, β-arrestin-1 and-2(also known as arrestin-2 and-3,respectively), have three major functions in cells: GPCR desensitization, i....The two ubiquitous, outside the retina, G protein-coupled receptor(GPCR)adapter proteins, β-arrestin-1 and-2(also known as arrestin-2 and-3,respectively), have three major functions in cells: GPCR desensitization, i.e.,receptor decoupling from G-proteins; GPCR internalization via clathrin-coated pits; and signal transduction independently of or in parallel to G-proteins. Bothβ-arrestins are expressed in the heart and regulate a large number of cardiac GPCRs. The latter constitute the single most commonly targeted receptor class by Food and Drug Administration-approved cardiovascular drugs, with about onethird of all currently used in the clinic medications affecting GPCR function.Since β-arrestin-1 and-2 play important roles in signaling and function of several GPCRs, in particular of adrenergic receptors and angiotensin II type 1 receptors,in cardiac myocytes, they have been a major focus of cardiac biology research in recent years. Perhaps the most significant realization coming out of their studies is that these two GPCR adapter proteins, initially thought of as functionally interchangeable, actually exert diametrically opposite effects in the mammalian myocardium. Specifically, the most abundant of the two β-arrestin-1 exerts overall detrimental effects on the heart, such as negative inotropy and promotion of adverse remodeling post-myocardial infarction(MI). In contrast, β-arrestin-2 is overall beneficial for the myocardium, as it has anti-apoptotic and antiinflammatory effects that result in attenuation of post-MI adverse remodeling,while promoting cardiac contractile function. Thus, design of novel cardiac GPCRligands that preferentially activate β-arrestin-2 over β-arrestin-1 has the potential of generating novel cardiovascular therapeutics for heart failure and other heart diseases.展开更多
心率和血氧饱和度是反映人体健康状况极其重要的生理指标.近年来,基于成像式光电容积描记技术(imaging photoplethysmography,IPPG)的非接触式心率和血氧饱和度检测方法因为其方便快捷且受约束较少等优点开始逐步成为研究热点.主要工作...心率和血氧饱和度是反映人体健康状况极其重要的生理指标.近年来,基于成像式光电容积描记技术(imaging photoplethysmography,IPPG)的非接触式心率和血氧饱和度检测方法因为其方便快捷且受约束较少等优点开始逐步成为研究热点.主要工作如下:首先,介绍了非接触式检测方法的背景和研究意义;其次,从目标区域检测和感兴趣区域(region of interest,ROI)选取两个方面总结并点明其研究现状以及未来改进方向;再次,从传统方法、信号处理结合深度学习方法以及端到端方法3个方面对心率和血氧饱和度检测方法进行了总结,并梳理了深度学习方法所使用的数据集以及在各个数据集中所展现的检测效果;最后,指出该领域所存在的亟待解决的问题以及未来的研究方向.展开更多
文摘The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound signals were denoised by using wavelet filters,the signals were applied bicoherence analysis that is an high order spectral analysis method.It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values.
文摘According to the definition of correlation dimension in fractal theory, this paper presented a method to determine and assess noise part in detected transient signal. Such work is essential to decrease the noise part in the detected signal. It is proved that heart period signal (HPS) is one typical sort of transient chaotic signal. Through experiment and simulation, the analysis of chaotic HPS in the detected signal was done. In the end, we deepen the researches on attractor dimension of HPS for persons who are different in age.
文摘The aim of this study was to develop a method for predicting the psychological states of spectators watching professional baseball games at a stadium. This method includes a real time measurement of instantaneous heart rate (i.e., the inverse of the RR interval) without preventing the subject from watching the game and a mathematical procedure used to predict moment by moment psychological states by correlating the degree of a psychological state with the strength of heart rate response, defined as the mean deviation of heart rate variability from a linear regression line from 5 sec before to 25 sec after an event during a baseball game. We recorded the instantaneous heart rates of 10 subjects (total of 27 cases) while they watched Japanese professional baseball games at a stadium and had them subjectively rate the degree of their psychological states in an after-event interview. We identified three psychological states (happiness, excitement, and vigor) whose strength can be predicted from the strength of heart rate response. Analysis of the measured data clarified that heart rate response had a significant correlation with the subjective rating of the intensity of happiness (r = 0.56, p < 0.0001), vigor (r = 0.55, p < 0.0001), and excitement (r = 0.49, p < 0.0001).
文摘Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate variability signal through the classical and time-frequency methods. At first, one minute of ECG signals, just before the cardiac death event are extracted and used to compute heart rate variability (HRV) signal. Five features in time domain and four features in frequency domain are extracted from the HRV signal and used as classical linear features. Then the Wigner Ville transform is applied to the HRV signal, and 11 extra features in the time-frequency (TF) domain are obtained. In order to improve the performance of classification, the principal component analysis (PCA) is applied to the obtained features vector. Finally a neural network classifier is applied to the reduced features. The obtained results show that the TF method can classify normal and SCD subjects, more efficiently than the classical methods. A MIT-BIH ECG database was used to evaluate the proposed method. The proposed method was implemented using MLP classifier and had 74.36% and 99.16% correct detection rate (accuracy) for classical features and TF method, respectively. Also, the accuracy of the KNN classifier were 73.87% and 96.04%.
基金a NSU’s President’s Faculty Research and Development Grant(PFRDG)
文摘The two ubiquitous, outside the retina, G protein-coupled receptor(GPCR)adapter proteins, β-arrestin-1 and-2(also known as arrestin-2 and-3,respectively), have three major functions in cells: GPCR desensitization, i.e.,receptor decoupling from G-proteins; GPCR internalization via clathrin-coated pits; and signal transduction independently of or in parallel to G-proteins. Bothβ-arrestins are expressed in the heart and regulate a large number of cardiac GPCRs. The latter constitute the single most commonly targeted receptor class by Food and Drug Administration-approved cardiovascular drugs, with about onethird of all currently used in the clinic medications affecting GPCR function.Since β-arrestin-1 and-2 play important roles in signaling and function of several GPCRs, in particular of adrenergic receptors and angiotensin II type 1 receptors,in cardiac myocytes, they have been a major focus of cardiac biology research in recent years. Perhaps the most significant realization coming out of their studies is that these two GPCR adapter proteins, initially thought of as functionally interchangeable, actually exert diametrically opposite effects in the mammalian myocardium. Specifically, the most abundant of the two β-arrestin-1 exerts overall detrimental effects on the heart, such as negative inotropy and promotion of adverse remodeling post-myocardial infarction(MI). In contrast, β-arrestin-2 is overall beneficial for the myocardium, as it has anti-apoptotic and antiinflammatory effects that result in attenuation of post-MI adverse remodeling,while promoting cardiac contractile function. Thus, design of novel cardiac GPCRligands that preferentially activate β-arrestin-2 over β-arrestin-1 has the potential of generating novel cardiovascular therapeutics for heart failure and other heart diseases.
文摘心率和血氧饱和度是反映人体健康状况极其重要的生理指标.近年来,基于成像式光电容积描记技术(imaging photoplethysmography,IPPG)的非接触式心率和血氧饱和度检测方法因为其方便快捷且受约束较少等优点开始逐步成为研究热点.主要工作如下:首先,介绍了非接触式检测方法的背景和研究意义;其次,从目标区域检测和感兴趣区域(region of interest,ROI)选取两个方面总结并点明其研究现状以及未来改进方向;再次,从传统方法、信号处理结合深度学习方法以及端到端方法3个方面对心率和血氧饱和度检测方法进行了总结,并梳理了深度学习方法所使用的数据集以及在各个数据集中所展现的检测效果;最后,指出该领域所存在的亟待解决的问题以及未来的研究方向.
