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Computers in Cardiology 1996最新文献

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Estimating myocardial activation times by maximum likelihood estimation 通过最大似然估计估计心肌激活次数
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542640
Hui Li, R. Malkin
{"title":"Estimating myocardial activation times by maximum likelihood estimation","authors":"Hui Li, R. Malkin","doi":"10.1109/CIC.1996.542640","DOIUrl":"https://doi.org/10.1109/CIC.1996.542640","url":null,"abstract":"In a cardiac isochronal map, myocardial dynamics are represented by activation times. Traditionally, ad-hoc methods (typically using the local minimum derivative of a unipolar electrogram, i.e., minimum first derivative algorithm) are used to detect myocardial activation times. We propose a statistical method, maximum likelihood (ML) estimation, to estimate myocardial activation times based on a dipole volume conductor model of a myocardial aggregate. Performance of the ML method is evaluated by repeated simulations with white noise. It is demonstrated that the ML method is more robust than the minimum first derivative algorithm. Further studies of the method are warranted perhaps with a more complicated model of noise and volume conductor, and with multiple electrodes.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"77 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":"121427740","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
The return map: simple test for diagnosing disrupted nervous control of the heart period variation in cardiac diseased patients 回归图:诊断心脏病患者心期变化神经控制紊乱的简单试验
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542585
J. Bieńkowski, M. Sosnowski, M. Tendera
{"title":"The return map: simple test for diagnosing disrupted nervous control of the heart period variation in cardiac diseased patients","authors":"J. Bieńkowski, M. Sosnowski, M. Tendera","doi":"10.1109/CIC.1996.542585","DOIUrl":"https://doi.org/10.1109/CIC.1996.542585","url":null,"abstract":"Studies the complexity of heart period variation in randomly selected population of 210 cardiac diseased patients and 26 healthy subjects. Repeated return maps with increasing time-lag from 1 to 6 was used. Each return map was quantified by calculation of coefficient of correlation Rret1 (to6). Rret1 was diminished in all groups of cardiac patients, as compared to controls (0.611+/-0.141). The lowest Rret1 values were observed in 35 pts suffering from intrinsic sinus node dysfunction (0.315+/-0.237), in 21 pts after myocardial infarction (0.360+/-0.189) and in 26 pts with unexplained syncope (0.395+/-0.174). They presented lower Rret values despite much weaker differences in magnitude of heart period variation. The authors concluded that increased complexity of RR variability is not accompanied by an increment of RR variation magnitude and could be find in patients with normal or decreased overall RR variation. The authors suggest to use the return map to detect abnormal neural control of heart rate in the presence of normal magnitude of its variation.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"107 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":"124122906","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
Cycles of ECG parameter evolution during ischemic episodes 缺血发作期间心电图参数演变的周期
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542580
J. Presedo, E. Fernández, J. Vila, S. Barro
{"title":"Cycles of ECG parameter evolution during ischemic episodes","authors":"J. Presedo, E. Fernández, J. Vila, S. Barro","doi":"10.1109/CIC.1996.542580","DOIUrl":"https://doi.org/10.1109/CIC.1996.542580","url":null,"abstract":"Presents a comparison between two different methods for analyzing ischemic episodes. Both methods are based on a beat by beat analysis of a large number of parameters. The authors process these data in order to extract information regarding the detection of meaningful cycles (presumably related to ischemic episodes) on ECG parameter evolution. In order to facilitate visual inspection of parameter evolution and thus facilitate the definition of criteria to detect such meaningful cycles, the authors apply a process for reducing the dimensionality of the parameter vector. To accomplish this task they employ both Principal Component Analysis (PCA) and Self-Organizing Maps (SOM). Considering a two dimensional output of these methods, the authors have observed that coinciding with ischemic episodes, a cycle starts moving away from a normality zone and moving back to that zone when the episode ends. As a preliminary result, the authors present graphic examples of these cycles over some of the records of the European ST-T Database.","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":"126373958","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: 9
Samples above the median: a nonparametric method for intracardiac signal assessment 中位数以上的样本:心内信号评估的非参数方法
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542475
M. Morris, J. Jenkins, L. DiCarlo
{"title":"Samples above the median: a nonparametric method for intracardiac signal assessment","authors":"M. Morris, J. Jenkins, L. DiCarlo","doi":"10.1109/CIC.1996.542475","DOIUrl":"https://doi.org/10.1109/CIC.1996.542475","url":null,"abstract":"In this investigation, a nonparametric (distribution-free) detection scheme, Samples Above the Median (SAM), is devised as an arrhythmia discriminant for implantable cardioverter defibrillators which is highly sensitive and specific yet introduces no appreciable computational demand. No widely accepted probability density function (p.d.f.) for intracardiac electrogram signals has been determined. A nonparametric method does not utilize the p.d.f. SAM was tested on 30 patients each with documented episodes of normal sinus rhythm (NSR) and ventricular tachycardia (VT). SAM achieved an electrogram specificity of 0.992 (476/480) and an electrogram sensitivity of 0.981 (471/480). SAM achieved an arrhythmia sensitivity and specificity of 1 using a 12 of 16 (75%) electrograms per arrhythmia criterion.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"16 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":"126478356","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
Separation of ventricular tachycardia from ventricular fibrillation using paired unipolar electrograms 使用成对单极电图分离室性心动过速和室性颤动
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542458
S. Caswell, J. A. Thompson, J. Jenkins, L. DiCarlo
{"title":"Separation of ventricular tachycardia from ventricular fibrillation using paired unipolar electrograms","authors":"S. Caswell, J. A. Thompson, J. Jenkins, L. DiCarlo","doi":"10.1109/CIC.1996.542458","DOIUrl":"https://doi.org/10.1109/CIC.1996.542458","url":null,"abstract":"In third-generation implantable antitachycardia devices, immediate defibrillation is necessary for ventricular fibrillation (VF) while lower-energy therapies convert many ventricular tachycardias (VTs). Precise distinction between true VF and VT is required if tiered-therapy is to be effectively utilized. To separate VF from VT, this study employed a measurement to quantify the coherence between two unipolar electrograms from the same catheter, where incoherence between signals indicates VF. A normalized cross correlation (CC) measured similarity, and standard deviation (STD) and interquartile range (IQR) of the CC measured consistency for sinus rhythm (SR), VT, and VF passages from 10 patients. Patient-independent STD thresholds of 0.15-0.25 and IQR thresholds of 0.3-0.6 provided 100% sensitivity and 100% specificity. This method was able to successfully separate VF from coherent rhythms (SR,VT). Proper distinction of VT would allow defibrillation to be deferred for consideration of lower energy therapies, providing significant energy savings.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"57 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":"127965388","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
Towards a generic domain information model in cardiology experience from OEDIPE 从OEDIPE走向心脏病学经验的通用领域信息模型
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542533
J.L. Ron, J. Fayn, P. Rubel
{"title":"Towards a generic domain information model in cardiology experience from OEDIPE","authors":"J.L. Ron, J. Fayn, P. Rubel","doi":"10.1109/CIC.1996.542533","DOIUrl":"https://doi.org/10.1109/CIC.1996.542533","url":null,"abstract":"Building generic models is an obvious trend in object-oriented engineering. The medical field is not an exception. In this paper we present an overview of the development framework of a Cardiology Workstation (CWS) and the underlying object oriented models, issued from the OEDIPE relational core data models. We demonstrate the models extensibility by showing how easy is the addition of other sources of data. The result is a set of classes and their relations assembled in a generic model that is intented to promote integration of information models of different medical specialities.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"8 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":"125597658","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
Bivariate spectral analysis of nonstationary cardiovascular variability series through cross Wigner distribution 通过交叉Wigner分布的非平稳心血管变异性序列的双变量光谱分析
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542478
S. Pola, M. Varanini, A. Macerata, M. Emdin, M. Cipriani, C. Marchesi
{"title":"Bivariate spectral analysis of nonstationary cardiovascular variability series through cross Wigner distribution","authors":"S. Pola, M. Varanini, A. Macerata, M. Emdin, M. Cipriani, C. Marchesi","doi":"10.1109/CIC.1996.542478","DOIUrl":"https://doi.org/10.1109/CIC.1996.542478","url":null,"abstract":"The Wigner Ville distribution has many of the desirable features required for the spectral analysis of cardiovascular series during the transients of autonomic tests, but it is not able to obtain insight into the mutual relationships between the series, making power measurements from the spectra often unreliable. This work proposes the Cross Wigner Distribution (CWD) as a new time-variant bivariate spectral analysis method. The CWD is compared with an approach based on adaptive filtering in order to evaluate its reliability in detecting correlated components between cardiovascular series.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"5 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":"115409231","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
Use of surface Laplacian to extract local activation from epicardial electrograms 利用表面拉普拉斯提取心外膜电图的局部激活
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542490
D. Geselowitz, P. Crombie, S. Smith, E. Berbari
{"title":"Use of surface Laplacian to extract local activation from epicardial electrograms","authors":"D. Geselowitz, P. Crombie, S. Smith, E. Berbari","doi":"10.1109/CIC.1996.542490","DOIUrl":"https://doi.org/10.1109/CIC.1996.542490","url":null,"abstract":"Electrocardiograms were recorded overlying a region of injury on the epicardial surface of a canine heart in a four day infarct model. Electrograms were recorded simultaneously from 121 sites with an electrode array with interelectrode spacing of 1 mm. The surface Laplacian, L, of the electrograms was calculated using the four neighboring sites. Propagation in the border zone was modeled by a planar wave of finite thickness moving with uniform velocity. The source region was simulated with use of the bidomain model for the heart. Computer model results showed that the amplitude of L, diminished as electrode spacing became larger than 0.1 mm. The amplitude also fell as the distance of the wave from the surface increased, decreasing by 40% for a depth of 0.1 mm. The surface Laplacian determined from recorded electrograms showed a sharp deflection with a substantial reduction in the QS wave arising from distant sources. Hence the surface Laplacian may be useful as a spatial filter to extract local activity from epicardial electrograms.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"42 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":"124294662","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
Modeling and simulation of the human cardiovascular system with bond graph: A basic development 基于键合图的人体心血管系统建模与仿真:一个基本发展
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542556
M. Diaz-Insua, M. Delgado
{"title":"Modeling and simulation of the human cardiovascular system with bond graph: A basic development","authors":"M. Diaz-Insua, M. Delgado","doi":"10.1109/CIC.1996.542556","DOIUrl":"https://doi.org/10.1109/CIC.1996.542556","url":null,"abstract":"A bond graph model of the cardiovascular system has been developed. With the model, changes in the blood pressure waveform are studied at different points in the systemic and pulmonary circulations, when exposed to a normal ventricular function. The waveforms thus obtained show a good model performance which reflects the actual waves, when compared with physiological human data. Wave reflection phenomena effects, capability in handling elements, addition of new compartments, and obtention of numerical data for spectral analysis are among the model features. These results and facilities offered by the \"intuitive\" and simple bond graph approach suggest its use, especially for life scientists, in the development of more detailed models for educational, research and clinical purposes.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"497 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":"114742401","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: 17
Normalization of the electrocardiogram by standardization of heart position and orientation 通过心脏位置和方位的标准化使心电图归一化
Computers in Cardiology 1996 Pub Date : 1996-09-08 DOI: 10.1109/CIC.1996.542637
R. Hoekema, G. Uijen, A. van Oosterom
{"title":"Normalization of the electrocardiogram by standardization of heart position and orientation","authors":"R. Hoekema, G. Uijen, A. van Oosterom","doi":"10.1109/CIC.1996.542637","DOIUrl":"https://doi.org/10.1109/CIC.1996.542637","url":null,"abstract":"In healthy subjects, a large inter-individual variability in the ECG is present. Part of this variability is intrinsically due to physiological differences in the heart. Other causes are differences in the position and orientation of the heart relative to the chest. In the current study, research was done to reduce the variability through the latter cause. In healthy volunteers, 64-lead body surface maps (BSMs) were recorded and the inter-individual variability was determined. Pericardial potentials were calculated from the BSMs using an individual realistic torso and heart model for each subject. Then, the heart in the model was moved and rotated into a standard position and orientation. Finally, forward calculations were made using the new heart position, while keeping the pericardial potential distribution unaltered. This yielded new electrode potentials at the 64 BSM leads. The inter-individual variability of the corrected signals was calculated and compared with the original variability. The realistic models were based on magnetic resonance images of the torso, lungs and heart of four healthy volunteers. Using BSM and MRI data of 4 subjects, the authors have carried out the described procedure. The variability of the sets of BSM data was 0.28 mV. The pericardial potentials were calculated (forward simulation of the results yielded an error of 10%). The variability after shifting and rotating the hearts towards a standard position was 0.23 mV. It is concluded that a reduction of variability is indeed found when standardizing heart position and orientation. A larger number of subjects will be included in this study to substantiate this result.","PeriodicalId":433138,"journal":{"name":"Computers in Cardiology 1996","volume":"103 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":"116420962","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: 5
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