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Computers in Cardiology 1996最新文献

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A discrete model of the dynamic behavior of the cardiac muscle 心肌动态行为的离散模型
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542610
E. Entcheva, F. Claydon
{"title":"A discrete model of the dynamic behavior of the cardiac muscle","authors":"E. Entcheva, F. Claydon","doi":"10.1109/CIC.1996.542610","DOIUrl":"https://doi.org/10.1109/CIC.1996.542610","url":null,"abstract":"The objective of this study is to construct a discrete finite state model of the electrical activity of the heart, which is directly related to the FitzHugh-Nagumo equations, but offers both a faster and more stable solution. The authors set up a 2D two variable model with non-nearest neighbor interactions to include curvature dependence of the wave front. For better approximation of the electrotonic propagation, a hexagonal grid and distance-dependent weighting coefficients are used. Despite its simplicity the model follows the local dynamics prescribed by the modified FitzHugh-Nagumo equations and its parameters are directly derived from the original ones. The model was validated by comparison to existing experimental data for the propagation velocity, curvature velocity relationship, rotation speed and core size. It was successfully used to study spiral wave interactions with nonexcitable obstacles of different shapes.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123499926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
New heart rate variability time-domain signal construction from the beat occurrence time and the IPFM model 从心跳发生时间和IPFM模型构建新的心率变异性时域信号
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542504
J. Mateo, P. Laguna
{"title":"New heart rate variability time-domain signal construction from the beat occurrence time and the IPFM model","authors":"J. Mateo, P. Laguna","doi":"10.1109/CIC.1996.542504","DOIUrl":"https://doi.org/10.1109/CIC.1996.542504","url":null,"abstract":"Heart rate variability (HRV) is an extended tool to analyse the mechanisms controlling the cardiovascular system. It is assuming the integral pulse frequency modulation model (IPFM) to explain the beat occurrence times generation. Spectral estimate methods try to infer the modulating signal characteristics from the available beat timing on the ECG signal. These methods usually estimate the spectrum through the heart period (HP) or the heart rate (HR) signals. In this work, the authors introduce a new HRV signal, the Heart Timing Signal, (HT) that allows one to recover an unbiased estimate of the modulating signal spectra avoiding the spurious components produced when analysing the modulating signal through HR or HP.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"24 5-6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123570300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 12
Time domain variability of high resolution beat-to-beat recordings classified by neural networks 神经网络分类高分辨率拍间记录的时域变异性
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542537
H. Kestler, M. Hoher, G. Palm, F. Schwenker, M. Kochs, V. Hombach
{"title":"Time domain variability of high resolution beat-to-beat recordings classified by neural networks","authors":"H. Kestler, M. Hoher, G. Palm, F. Schwenker, M. Kochs, V. Hombach","doi":"10.1109/CIC.1996.542537","DOIUrl":"https://doi.org/10.1109/CIC.1996.542537","url":null,"abstract":"This study assesses the beat-to-beat variation of the time-domain QRS signal in normals and in patients with malignant ventricular arrhythmia using a multilayer perceptron neural network. High-resolution beat-to beat ECGs were recorded in 51 normals and in 46 CHD patients with inducible sustained VT (sVT). Per individual one variability vector was calculated. Total time-domain QRS variability, calculated as the sum of the elements of the variability vector (vector of standard deviations), was significantly higher in patients with inducible VT than in normals. To establish a user independent classification a multilayer perceptron was utilized on the variability vector. Solely based on the variability information of the QRS, the neural net gained a classification accuracy comparable to the standard time-domain approach. We conclude that patients with sVT show a significantly higher beat-to-beat variation inside the time domain QRS, possibly reflecting microvariations of the myocardial excitation.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129665984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 15
Detection of atrial activity from high voltage leads of implantable ventricular defibrillators 植入式心室除颤器高压导联检测心房活动
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542477
S. Shkurovich, A. Sahakian, S. Swiryn
{"title":"Detection of atrial activity from high voltage leads of implantable ventricular defibrillators","authors":"S. Shkurovich, A. Sahakian, S. Swiryn","doi":"10.1109/CIC.1996.542477","DOIUrl":"https://doi.org/10.1109/CIC.1996.542477","url":null,"abstract":"In this study, the authors examined the atrial activity content of high voltage (HV) lead signals of implantable cardioverter defibrillators (ICDs) during device implantation. They also attempted to detect atrial fibrillation (AFib) by analyzing these signals. They used a method that canceled ventricular and correlated atrial activity from the HV lead signals and measured frequency and amplitude distribution information to discriminate sinus rhythm and AFib segments. The results suggest that atrial activity is present in HV lead signals, and AFib detection can be achieved in many, but not all cases, using information currently available to ICDs.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128869303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
The relation between QT intervals and heart rate in young healthy males using an incremental head-up tilt protocol QT间期与年轻健康男性心率的关系
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542529
J.V. Levert, A. Maan, C. A. Swenne, M. Bootsma, A. Bruschke
{"title":"The relation between QT intervals and heart rate in young healthy males using an incremental head-up tilt protocol","authors":"J.V. Levert, A. Maan, C. A. Swenne, M. Bootsma, A. Bruschke","doi":"10.1109/CIC.1996.542529","DOIUrl":"https://doi.org/10.1109/CIC.1996.542529","url":null,"abstract":"The relationship between the QT interval and the preceding RR interval is often described by a simple formula with 1 or 2 parameters like, e.g., Bazett's correction formula or an exponential formula. These formulas may perform adequately in large groups of people, but not in individuals. The authors describe an incremental head-up tilt protocol to obtain QT intervals at a large range of different heart rates in individuals within 3 hr under minimal changes in conditions. The resulting QT-RR relationship is complex and differs for each individual, but all curves share some common characteristics.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125531027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
On the use of wavelets to separate dynamical activities embedded in a time series 用小波来分离嵌入在时间序列中的动态活动
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542503
A. Casaleggio, B. Gramatikov, N. Thakor
{"title":"On the use of wavelets to separate dynamical activities embedded in a time series","authors":"A. Casaleggio, B. Gramatikov, N. Thakor","doi":"10.1109/CIC.1996.542503","DOIUrl":"https://doi.org/10.1109/CIC.1996.542503","url":null,"abstract":"In this work a first attempt is made to separate dynamical activity in signals by decomposing frequency sub-bands of the original observable signal. The authors use multiresolution wavelets to decompose electrocardiogram (ECG) signals into several frequency sub-bands and calculated the correlation dimension to determine the presence or absence of low-dimensional dynamics. Although the results must be considered as very preliminary, some evidence is presented to show that a low dimensional activity precedes the actual incidence of the tachyarrhythmia. The authors hypothesize the signal decomposition by wavelet analysis may enhance the ability to locate low dimensional activity in cardiac arrhythmias.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121318534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Blood pressure evaluation based on arterial pulse wave velocity 基于动脉脉搏波速度的血压评估
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542557
D. Franchi, R. Bedini, F. Manfredini, S. Berti, G. Palagi, S. Ghione, A. Ripoli
{"title":"Blood pressure evaluation based on arterial pulse wave velocity","authors":"D. Franchi, R. Bedini, F. Manfredini, S. Berti, G. Palagi, S. Ghione, A. Ripoli","doi":"10.1109/CIC.1996.542557","DOIUrl":"https://doi.org/10.1109/CIC.1996.542557","url":null,"abstract":"Pulse wave transit time assessment and peripheral pressure waveform analysis are being developed for noninvasive estimation of arterial blood pressure. In the present work we investigate the dependence of the pulse wave velocity from the aortic pressure by an appropriate mathematical model and by an ad hoc developed computerised acquisition system of blood pressure waveform and sphygmic wave during cath-lab session. The relationship between the ECG, the peripheral plethysmographic wave and the intra-aortic pressure have been studied in detail. The pulse wave has been detected by means of a transmission photo-plethysmographic device (located at the ear lobe) while the aortic pressure waveform is acquired by means of a fluid-filled pressure transducer. The selected operative condition allows signal acquisition in different controlled situations following specified experimental protocols (rest condition, hand grip and Valsalva's manoeuvre). The acquisition system is composed of a PC equipped with an acquisition board. The signals, acquired at a sampling frequency of 2000 Hz, to assure the necessary time resolution, and on-line displayed are: one lead ECG, the peripheral pulse wave and the aortic pressure. An algorithm has been properly developed for the delay evaluation between R wave, aortic pressure and pulse wave onset. Beat to beat systolic, diastolic and mean aortic pressure values have been carried out. The collected data have been investigated from the statistical point of view looking for appropriate correlation between the pressure and two delays: R wave - aortic pulse; aortic pulse - peripheral pulse wave. The diastolic pressure seems more estimable in the arterial path.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126253753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 26
Effects of metronome breathing on the assessment of autonomic control using heart rate variability 节拍器呼吸对利用心率变异性评估自主控制的影响
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542482
J. Haaksma, J. Brouwer, M. van den Berg, W. Dijk, W. Dassen, L. Mulder, G. Mulder, H. Crijns
{"title":"Effects of metronome breathing on the assessment of autonomic control using heart rate variability","authors":"J. Haaksma, J. Brouwer, M. van den Berg, W. Dijk, W. Dassen, L. Mulder, G. Mulder, H. Crijns","doi":"10.1109/CIC.1996.542482","DOIUrl":"https://doi.org/10.1109/CIC.1996.542482","url":null,"abstract":"Analysis of Heart Rate Variability is a non-invasive quantitative tool to study the influence of the autonomic nervous system on the heart. Rapid variations in heart rate, related to breathing are primarily mediated by the vagal limb of the autonomic nervous system. The resulting variations in heart rate are usually referred to as respiratory sinus arrhythmia. Metronome breathing (MB) is often advocated to assess more accurately vagal control. However, the additional value of MB over SB has never been established. The authors studied the effect of MB (0.25 Hz) on HRV variables in 12 healthy male subjects under stable conditions using pharmacological autonomic blockade. During MB several variables showed a lower absolute value, however a strong correlation existed between variables computed during spontaneous breathing (SB) and MB. MB offers some, but no important advantages over spontaneous breathing.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115974893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Left ventricular wall stress and thickness from 3D echocardiography in hypertensive patients 高血压患者三维超声心动图左室壁应力和厚度
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542562
M. Baroni, G. Barletta, R. Del Bene, F. Fantini
{"title":"Left ventricular wall stress and thickness from 3D echocardiography in hypertensive patients","authors":"M. Baroni, G. Barletta, R. Del Bene, F. Fantini","doi":"10.1109/CIC.1996.542562","DOIUrl":"https://doi.org/10.1109/CIC.1996.542562","url":null,"abstract":"The authors applied a previously described method for 3D LV reconstruction from a limited number of long-axis 2D echocardiographic images to obtain epicardial and endocardial surfaces. By intersecting a regularly-spaced set of lines perpendicular to the center-surface with the endocardial and epicardial surfaces, LV local thickness was measured. Accuracy was improved by considering cubic spline patches rather than planar ones. LV volumes, mass and Janz's stress index were computed. The goal of this work was to quantitatively evaluate the degree of LV hypertrophy, its spatial distribution in 21 patients with hypertension and to compare them to the standard M-mode mass values. Results indicate a good correlation between conventional echocardiographic and 3D estimated mass. Different patterns in the spatial distribution of myocardial hypertrophy were responsible for a scattering of data.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115978860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Automated assessment of color Doppler M-mode early diastolic flow propagation features 彩色多普勒m型早期舒张期血流传播特征的自动评估
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542508
N. Greenberg, M. Stugaard, P. Vandervoort, J.D. Thomas
{"title":"Automated assessment of color Doppler M-mode early diastolic flow propagation features","authors":"N. Greenberg, M. Stugaard, P. Vandervoort, J.D. Thomas","doi":"10.1109/CIC.1996.542508","DOIUrl":"https://doi.org/10.1109/CIC.1996.542508","url":null,"abstract":"Color Doppler M-mode echocardiographic imaging has been shown to provide useful information in the evaluation of left ventricular diastolic filling and function. However, descriptors of the spatiotemporal velocity inflow pattern do not take advantage of the full digital velocity map and are not available in an automated fashion. The purpose of this study was to automate the quantification of flow propagation features and evaluate their ability to assess diastolic filling abnormalities. Isovelocity contouring and gradient analysis were applied to identify features of the early filling wave. These feature parameters were compared in normal and diastolic dysfunction patient groups (N=20). Several features allowed classification of the two patient groups with sensitivity and specificity greater than 80%. This automated process may allow these features to be obtained on a regular basis and provide information for diagnosis and assessment of diastolic dysfunction.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125287915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
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