Z. Czyz̊, T. Petelenz, Z. Flak, M. Sosnowski, J. Leski
Presents a new procedure of P-waved triggered signal averaging ECG and its utility for paroxysmal atrial fibrillation (PAI) risk assessment in patients (pts) suffering from mitral valve disease (MVD). A study was performed in 20 MVD-pts with PAF, in 10 MVD-pts without PAF and in 10 healthy subjects. Time-domain analysis after filtration 25-250 Hz and 40-250 Hz provided the following parameters: P complex duration (PD), RMS of total P complex (RMSP) and of its terminal 10, 20 and 30 ms. FFT frequency-domain analysis, performed on the 120 ms segment, provided for each X, Y or Z lead the percentage ratio of spectral areas at bands: 20-50/0-20 Hz (AR1) and 60-120/0-120 (AR2). At 40-120 Hz filtration all time-domain variables significantly differed for MVD-PAF(+)-pts from PAF(-) subjects. Frequency analysis showed that ARI was significantly higher in PAF(+) than in the remaining examined subjects without PAF.<>
{"title":"A time and frequency domain analysis of atrial late potentials for paroxysmal atrial fibrillation risk assessment","authors":"Z. Czyz̊, T. Petelenz, Z. Flak, M. Sosnowski, J. Leski","doi":"10.1109/CIC.1993.378508","DOIUrl":"https://doi.org/10.1109/CIC.1993.378508","url":null,"abstract":"Presents a new procedure of P-waved triggered signal averaging ECG and its utility for paroxysmal atrial fibrillation (PAI) risk assessment in patients (pts) suffering from mitral valve disease (MVD). A study was performed in 20 MVD-pts with PAF, in 10 MVD-pts without PAF and in 10 healthy subjects. Time-domain analysis after filtration 25-250 Hz and 40-250 Hz provided the following parameters: P complex duration (PD), RMS of total P complex (RMSP) and of its terminal 10, 20 and 30 ms. FFT frequency-domain analysis, performed on the 120 ms segment, provided for each X, Y or Z lead the percentage ratio of spectral areas at bands: 20-50/0-20 Hz (AR1) and 60-120/0-120 (AR2). At 40-120 Hz filtration all time-domain variables significantly differed for MVD-PAF(+)-pts from PAF(-) subjects. Frequency analysis showed that ARI was significantly higher in PAF(+) than in the remaining examined subjects without PAF.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"9 1","pages":"45-48"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75782593","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}
The authors present preliminary results and new technical developments in measurement of cross-sectional blood velocities and flow from a time-sequence of arteriograms. They apply the conservation of mass principle to flowing blood and the injected contrast medium in a vessel in order to obtain mathematical constraints on cross sectional velocities from a sequence of contrast-injected images. The previously employed optical flow constraint discussed by Mongrain et al. (Computers in Cardiology, 1991) and other authors is found to be a special case of this constraint. The proposed framework is also particularly efficient. The numerical methods compute a stream function (a single image) from a window of images in a time-sequence, and in a post-processing step, the cross-sectional velocity field is determined simply by application, of a gradient operator to the stream function.<>
作者介绍了从动脉造影时间序列测量横断面血流速度和流量的初步结果和新技术进展。他们将质量守恒原理应用于血管中流动的血液和注入的造影剂，以便从一系列注入造影剂的图像中获得横截面速度的数学约束。Mongrain et al. (Computers in Cardiology, 1991)和其他作者讨论的先前使用的光流约束是这种约束的一个特例。拟议的框架也特别有效。数值方法从时间序列的图像窗口中计算流函数(单个图像)，在后处理步骤中，截面速度场仅通过对流函数应用梯度算子来确定。
{"title":"Physical models for measurement of blood velocity and flow from diagnostic images","authors":"A. Amini, T. Egglin, J. Pollak","doi":"10.1109/CIC.1993.378368","DOIUrl":"https://doi.org/10.1109/CIC.1993.378368","url":null,"abstract":"The authors present preliminary results and new technical developments in measurement of cross-sectional blood velocities and flow from a time-sequence of arteriograms. They apply the conservation of mass principle to flowing blood and the injected contrast medium in a vessel in order to obtain mathematical constraints on cross sectional velocities from a sequence of contrast-injected images. The previously employed optical flow constraint discussed by Mongrain et al. (Computers in Cardiology, 1991) and other authors is found to be a special case of this constraint. The proposed framework is also particularly efficient. The numerical methods compute a stream function (a single image) from a window of images in a time-sequence, and in a post-processing step, the cross-sectional velocity field is determined simply by application, of a gradient operator to the stream function.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"21 1","pages":"783-786"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75880569","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}
B. Sharif, D. Thomson, E. G. Chester, R. Campbell, S. Furniss
Accurate localisation of arrhythmogenic origin is necessary for successful surgery on patients with ventricular arrhythmias, and fragmentation mapping is one of the principal techniques used intraoperatively for this purpose. Fragmentation mapping is normally based on subjective characterisation of fragmented cardiac myopotentials. These fragmented electrograms are an important feature of arrhythmogenic scar and have been used with moderate success to direct surgery. However, very little is known or understood about fragmented electrograms. The aim of the authors' study is to produce a fragmentation mapping system based on the automated classification of electrograms. Therefore, the two main issues that are addressed are the extraction of electrograms from recorded and occasionally noisy signals and evaluating the characteristics applicable to discriminating between normal and abnormal electrograms. The output of the fragmentation mapping system is in the form of a graphical map representing 53 grid positions on the left ventricular epicardium. This will provide a useful tool that will potentially localise the arrhythmogenic origin more rapidly than manual schemes, thus allowing a more effective treatment of arrhythmias.<>
{"title":"Ventricular arrhythmia localisation by computer processing of fragmented cardiac myopotentials","authors":"B. Sharif, D. Thomson, E. G. Chester, R. Campbell, S. Furniss","doi":"10.1109/CIC.1993.378484","DOIUrl":"https://doi.org/10.1109/CIC.1993.378484","url":null,"abstract":"Accurate localisation of arrhythmogenic origin is necessary for successful surgery on patients with ventricular arrhythmias, and fragmentation mapping is one of the principal techniques used intraoperatively for this purpose. Fragmentation mapping is normally based on subjective characterisation of fragmented cardiac myopotentials. These fragmented electrograms are an important feature of arrhythmogenic scar and have been used with moderate success to direct surgery. However, very little is known or understood about fragmented electrograms. The aim of the authors' study is to produce a fragmentation mapping system based on the automated classification of electrograms. Therefore, the two main issues that are addressed are the extraction of electrograms from recorded and occasionally noisy signals and evaluating the characteristics applicable to discriminating between normal and abnormal electrograms. The output of the fragmentation mapping system is in the form of a graphical map representing 53 grid positions on the left ventricular epicardium. This will provide a useful tool that will potentially localise the arrhythmogenic origin more rapidly than manual schemes, thus allowing a more effective treatment of arrhythmias.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"16 1","pages":"141-144"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73237839","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}
Andrzej Piatkowski, E. Piątkowska-Janko, G. Opolski
The aim of the authors' study was to assess the optimal filter for late potentials (LP) determination. They present their study of time-domain signal-averaged electrocardiogram (SAECG) in patients with bundle branch block.<>
{"title":"Analysis of digital filtering in high-resolution electrocardiography: new method of SAECG analysis for patients identification with bundle branch block and sustained ventricular tachycardia after myocardial infarction","authors":"Andrzej Piatkowski, E. Piątkowska-Janko, G. Opolski","doi":"10.1109/CIC.1993.378503","DOIUrl":"https://doi.org/10.1109/CIC.1993.378503","url":null,"abstract":"The aim of the authors' study was to assess the optimal filter for late potentials (LP) determination. They present their study of time-domain signal-averaged electrocardiogram (SAECG) in patients with bundle branch block.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"25 1","pages":"65-67"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77675918","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}
The study relates to the control of the mechanical activity of the cardiac muscle by coupling calcium kinetics with crossbridge cycling. Two main feedback mechanisms affect the performance of the contractile filaments: 1) cooperativity, in which the affinity of troponin for calcium is a function of the number of cycling crossbridges, and 2) mechanical feedback where the velocity of filament sliding affects crossbridge turnover rate from the strong to the weak conformation. This intracellular control mechanism describes the performances of the skinned and intact cardiac muscle at various loading conditions, i.e. the force-length and the force-velocity relationships and the control of relaxation. The model can also describe the effect of various loading conditions on the work and ATP consumption. Using this approach, a mechanism for the time varying elastance of the left ventricle is proposed.<>
{"title":"Time varying elastance and cardiac muscle energetics based on calcium kinetics and crossbridges cycling","authors":"A. Landesberg, R. Beyar, S. Sideman","doi":"10.1109/CIC.1993.378426","DOIUrl":"https://doi.org/10.1109/CIC.1993.378426","url":null,"abstract":"The study relates to the control of the mechanical activity of the cardiac muscle by coupling calcium kinetics with crossbridge cycling. Two main feedback mechanisms affect the performance of the contractile filaments: 1) cooperativity, in which the affinity of troponin for calcium is a function of the number of cycling crossbridges, and 2) mechanical feedback where the velocity of filament sliding affects crossbridge turnover rate from the strong to the weak conformation. This intracellular control mechanism describes the performances of the skinned and intact cardiac muscle at various loading conditions, i.e. the force-length and the force-velocity relationships and the control of relaxation. The model can also describe the effect of various loading conditions on the work and ATP consumption. Using this approach, a mechanism for the time varying elastance of the left ventricle is proposed.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"46 1","pages":"373-376"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83604747","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}
MULTIWAVE is a multiresolution wavelet-based algorithm for data compression of ECG signals. ECG signals are decomposed into coarse and fine components. Decomposition is carried out by a pyramidal algorithm that analyzes the signal at successive scales by convolution with an orthonormal set of filters, followed by decimation (discarding the alternate samples). Data compression rates of 2:1, 4:1, 8:1, and so on are obtained at each successive scale. Four records each of normal sinus rhythm (NSR), supraventricular tachycardia (SVT), and ventricular tachycardia (VT) are analyzed. The performance of the MULTIWAVE algorithm is found to be superior to that of the TURNING POINT algorithm at all compression rates for all ECG records.<>
{"title":"MULTIWAVE: a multiresolution wavelet-based ECG data compression algorithm","authors":"N. Thakor, Y. Sun, Hervé Rix, P. Caminal","doi":"10.1109/CIC.1993.378421","DOIUrl":"https://doi.org/10.1109/CIC.1993.378421","url":null,"abstract":"MULTIWAVE is a multiresolution wavelet-based algorithm for data compression of ECG signals. ECG signals are decomposed into coarse and fine components. Decomposition is carried out by a pyramidal algorithm that analyzes the signal at successive scales by convolution with an orthonormal set of filters, followed by decimation (discarding the alternate samples). Data compression rates of 2:1, 4:1, 8:1, and so on are obtained at each successive scale. Four records each of normal sinus rhythm (NSR), supraventricular tachycardia (SVT), and ventricular tachycardia (VT) are analyzed. The performance of the MULTIWAVE algorithm is found to be superior to that of the TURNING POINT algorithm at all compression rates for all ECG records.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"39 1","pages":"393-396"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84605571","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}
The aim of this study was to compare, against manual measurement, 3 algorithms for automatic QT interval measurement using eight 4 lead ECGs recorded from normal subjects. The algorithms investigated determined T wave end from (a) the intercept of the isoelectric line and maximum T wave slope, thresholds applied to (b) the T wave and (c) the differential of the T wave. Mean manual-automatic QT measurement differences of 27 to 29 ms for algorithm a, -2 to 20 ms for b and -5 to 4 ms for c were found. The standard deviations (SD) of the manual-automatic differences varied from 9 to 30 ms. Failure to measure the QT interval (1 to 12 cases) occurred with only algorithm b. Each algorithm performed differently with the mean and SD of the differences, and failure rate for b, dependent on threshold and isoelectric levels used.<>
{"title":"Accuracy of automatic QT measurement techniques","authors":"N. McLaughlin, R. Campbell, A. Murray","doi":"10.1109/CIC.1993.378348","DOIUrl":"https://doi.org/10.1109/CIC.1993.378348","url":null,"abstract":"The aim of this study was to compare, against manual measurement, 3 algorithms for automatic QT interval measurement using eight 4 lead ECGs recorded from normal subjects. The algorithms investigated determined T wave end from (a) the intercept of the isoelectric line and maximum T wave slope, thresholds applied to (b) the T wave and (c) the differential of the T wave. Mean manual-automatic QT measurement differences of 27 to 29 ms for algorithm a, -2 to 20 ms for b and -5 to 4 ms for c were found. The standard deviations (SD) of the manual-automatic differences varied from 9 to 30 ms. Failure to measure the QT interval (1 to 12 cases) occurred with only algorithm b. Each algorithm performed differently with the mean and SD of the differences, and failure rate for b, dependent on threshold and isoelectric levels used.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"95 1","pages":"863-866"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78532016","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}
E. Cervesato, G. Nicolosi, G. Rellini, D. Zanuttini
To allow a full and easy integration between digital ECG storage and clinical database, routine ECGs are transferred to a local area network using a RS232 communication line. Sample data are available on the 8 independent leads in decompressed format. The ECGs are linked with the clinical database so that they can be easily reviewed during routine operations. When recalled by the operator, the ECG is displayed on a full screen in its original format together with the interpretation. A grey to scale algorithm improves the graphic resolution even using conventional VGA display cards. Double size zoom and high quality reprint are also available. A seven month pilot clinical test was performed with excellent results.<>
{"title":"A new approach to ECG tracing storage allowing full integration with clinical database","authors":"E. Cervesato, G. Nicolosi, G. Rellini, D. Zanuttini","doi":"10.1109/CIC.1993.378341","DOIUrl":"https://doi.org/10.1109/CIC.1993.378341","url":null,"abstract":"To allow a full and easy integration between digital ECG storage and clinical database, routine ECGs are transferred to a local area network using a RS232 communication line. Sample data are available on the 8 independent leads in decompressed format. The ECGs are linked with the clinical database so that they can be easily reviewed during routine operations. When recalled by the operator, the ECG is displayed on a full screen in its original format together with the interpretation. A grey to scale algorithm improves the graphic resolution even using conventional VGA display cards. Double size zoom and high quality reprint are also available. A seven month pilot clinical test was performed with excellent results.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"36 1","pages":"559-562"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87471307","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}
Coronary angiograms are degraded by blur and noise from the imaging system. Previously the authors proposed a method of deblurring and edge-preserving smoothing using Mean Field Annealing. Here, they show the results of the application of DMFA technique on clinical cineangiography. Also, they propose a new edge detection method which uses densitometric information as well as gradient information in the estimation of the edges. These techniques are applied to 13 synthetic vessel images and several clinical angiograms and the results are compared to those of the conventional gradient-based techniques. These methods may improve QCA measures of vessel diameters.<>
{"title":"Quantitative angiography: densitometry guided edge detection using mean field annealing","authors":"Youn-Sik Han, W. Snyder, D. Herrington","doi":"10.1109/CIC.1993.378493","DOIUrl":"https://doi.org/10.1109/CIC.1993.378493","url":null,"abstract":"Coronary angiograms are degraded by blur and noise from the imaging system. Previously the authors proposed a method of deblurring and edge-preserving smoothing using Mean Field Annealing. Here, they show the results of the application of DMFA technique on clinical cineangiography. Also, they propose a new edge detection method which uses densitometric information as well as gradient information in the estimation of the edges. These techniques are applied to 13 synthetic vessel images and several clinical angiograms and the results are compared to those of the conventional gradient-based techniques. These methods may improve QCA measures of vessel diameters.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"43 1","pages":"105-108"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88266976","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}
Zuo-Jun Max Shen, Malcolm Clarke, Ronald W. Jones, T. Alberti
The authors used a neural network (NN) on data from a self-applied questionnaire to implement a decision system designed to seek out high risk individuals in a large population. A multilayered perceptron was trained with various risk factors to distinguish coronary heart disease. The performance of the NN was evaluated by receiver operating characteristic (ROC) analysis. A maximum ROC area of 98% was obtained. The authors also describe a modification to the architecture of the neural network in which an extra layer of neurons is added at the input. They present possible interpretations of the weights of these neurons and show how they can be used as a selection criteria for which questions to use as inputs. The technique is compared against other statistical methods. The authors go on to demonstrate the system's capability for detecting both the symptomatic and asymptomatic patient.<>
{"title":"A neural network approach to the detection of coronary artery disease","authors":"Zuo-Jun Max Shen, Malcolm Clarke, Ronald W. Jones, T. Alberti","doi":"10.1109/CIC.1993.378464","DOIUrl":"https://doi.org/10.1109/CIC.1993.378464","url":null,"abstract":"The authors used a neural network (NN) on data from a self-applied questionnaire to implement a decision system designed to seek out high risk individuals in a large population. A multilayered perceptron was trained with various risk factors to distinguish coronary heart disease. The performance of the NN was evaluated by receiver operating characteristic (ROC) analysis. A maximum ROC area of 98% was obtained. The authors also describe a modification to the architecture of the neural network in which an extra layer of neurons is added at the input. They present possible interpretations of the weights of these neurons and show how they can be used as a selection criteria for which questions to use as inputs. The technique is compared against other statistical methods. The authors go on to demonstrate the system's capability for detecting both the symptomatic and asymptomatic patient.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"71 1","pages":"221-224"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86153461","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}
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