A finite element model is described which permits the rapid solution of realistic defibrillation shock problems on personal computers. It has been developed with the aim of increasing the clinical availability of such techniques.<>
{"title":"Customising implantable defibrillator electrodes: an efficient finite element model for desktop personal computers","authors":"E. Seneta, L. Holley","doi":"10.1109/CIC.1993.378507","DOIUrl":"https://doi.org/10.1109/CIC.1993.378507","url":null,"abstract":"A finite element model is described which permits the rapid solution of realistic defibrillation shock problems on personal computers. It has been developed with the aim of increasing the clinical availability of such techniques.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"13 1","pages":"49-52"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78370003","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}
G. Z. Yang, P. Kilner, D. N. Firmin, S. R. Underwood, Peter C. Burger, D. Longmore
Using quantitative magnetic resonance (MR) flow imaging techniques for performing in vivo flow, measurement has already established its value in medical practice. Due to time limitations, however, compromises have to be made in studies of 3-dimensional pulsatile flow. Velocity distributions are usually acquired only in selected imaging planes. Although recent development of rapid MR 3D cine flow imaging techniques has greatly improved the comprehensiveness of flow data acquired, it is achieved at the cost of some reduction of signal to noise ratio and spatial resolution. The objective of this study is to use the technique of convex projections to reconstruct 3D velocity fields from incomplete or noisy data sets. The theory and numerical implementation of these projectors are presented.<>
{"title":"3D cine velocity reconstruction using the method of convex projections","authors":"G. Z. Yang, P. Kilner, D. N. Firmin, S. R. Underwood, Peter C. Burger, D. Longmore","doi":"10.1109/CIC.1993.378429","DOIUrl":"https://doi.org/10.1109/CIC.1993.378429","url":null,"abstract":"Using quantitative magnetic resonance (MR) flow imaging techniques for performing in vivo flow, measurement has already established its value in medical practice. Due to time limitations, however, compromises have to be made in studies of 3-dimensional pulsatile flow. Velocity distributions are usually acquired only in selected imaging planes. Although recent development of rapid MR 3D cine flow imaging techniques has greatly improved the comprehensiveness of flow data acquired, it is achieved at the cost of some reduction of signal to noise ratio and spatial resolution. The objective of this study is to use the technique of convex projections to reconstruct 3D velocity fields from incomplete or noisy data sets. The theory and numerical implementation of these projectors are presented.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"11 1","pages":"361-364"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75053418","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}
U. Tachinardi, M. Gutierrez, L. Moura, B. Leao, C. Meneghetti, C. P. Melo
Image storage and retrieval make medical image departments unique in terms of information systems. The PACS concept was developed as a solution for integrating medical image systems. On the other hand, hospital information systems (HIS) were oriented towards text-based data. Today many hospitals suffer from the lack of integration between both systems. In the authors' institution this question was addressed a few years ago and the authors have decided to develop a fresh HIS with PACS embedded capabilities. To approach this problem, a small-scale prototype is under implementation at InCor's Nuclear Cardiology Department. Here, the authors highlight the importance of using open systems and conceptual modeling to make PACS and HIS integration not only feasible but also rewarding.<>
{"title":"Integrating PACS and HIS in a nuclear cardiology department","authors":"U. Tachinardi, M. Gutierrez, L. Moura, B. Leao, C. Meneghetti, C. P. Melo","doi":"10.1109/CIC.1993.378359","DOIUrl":"https://doi.org/10.1109/CIC.1993.378359","url":null,"abstract":"Image storage and retrieval make medical image departments unique in terms of information systems. The PACS concept was developed as a solution for integrating medical image systems. On the other hand, hospital information systems (HIS) were oriented towards text-based data. Today many hospitals suffer from the lack of integration between both systems. In the authors' institution this question was addressed a few years ago and the authors have decided to develop a fresh HIS with PACS embedded capabilities. To approach this problem, a small-scale prototype is under implementation at InCor's Nuclear Cardiology Department. Here, the authors highlight the importance of using open systems and conceptual modeling to make PACS and HIS integration not only feasible but also rewarding.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"16 1","pages":"819-822"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75021849","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}
Methods based on region matching to estimate velocity field on sequences of 2-D echocardiograms are presented and tested. The method proposed by Singh and Allen (CVGIP: Image Understanding, vol. 56, p. 152-77, 1992) has been modified in the choice of the similarity index. Results of test based on sequences of synthesized images show that template matching methods are more robust and accurate than gradient based methods, while on the other hand computation time is much higher.<>
提出并验证了基于区域匹配的二维超声心动图序列速度场估计方法。Singh和Allen (CVGIP: Image Understanding, vol. 56, p. 152-77, 1992)提出的方法在相似性指数的选择上进行了修改。基于合成图像序列的测试结果表明，模板匹配方法比基于梯度的方法具有更强的鲁棒性和准确性，但计算时间要长得多。
{"title":"Region based matching for velocity field computation in 2-D echocardiography","authors":"C. Lamberti, P. Bottazzi, A. Sarti","doi":"10.1109/CIC.1993.378379","DOIUrl":"https://doi.org/10.1109/CIC.1993.378379","url":null,"abstract":"Methods based on region matching to estimate velocity field on sequences of 2-D echocardiograms are presented and tested. The method proposed by Singh and Allen (CVGIP: Image Understanding, vol. 56, p. 152-77, 1992) has been modified in the choice of the similarity index. Results of test based on sequences of synthesized images show that template matching methods are more robust and accurate than gradient based methods, while on the other hand computation time is much higher.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"6 1","pages":"739-742"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76265330","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}
G. Dori, S. Ben-Haim, Y. Galamidi, B. Lewis, D. Hagan
Percutaneous transluminal coronary angioplasty (PTCA) is a unique clinical setup by which the effects of acute cardiac ischemia in humans may be investigated. The present study was designed to assess qualitative changes in ECG waveforms during acute ischemia induced by balloon inflation (BI). 16 patients underwent PTCA; we analyzed and compared the effect of BI on body surface ECG, as well as ECG derived phase planes, and the quality of distribution of the Poincare/spl acute/ sections (PS). We found that only 50% of the ECG tracings demonstrate morphological changes during BI. In 12 of 16 patients (75%) the PS distribution was qualitatively changed during BI. We conclude that such a change implies of a nonlinear deterministic feature of the system underlying the electrical signal of the human heart.<>
{"title":"Is the system underlying the electrical signal of the human heart a non-linear deterministic system?","authors":"G. Dori, S. Ben-Haim, Y. Galamidi, B. Lewis, D. Hagan","doi":"10.1109/CIC.1993.378416","DOIUrl":"https://doi.org/10.1109/CIC.1993.378416","url":null,"abstract":"Percutaneous transluminal coronary angioplasty (PTCA) is a unique clinical setup by which the effects of acute cardiac ischemia in humans may be investigated. The present study was designed to assess qualitative changes in ECG waveforms during acute ischemia induced by balloon inflation (BI). 16 patients underwent PTCA; we analyzed and compared the effect of BI on body surface ECG, as well as ECG derived phase planes, and the quality of distribution of the Poincare/spl acute/ sections (PS). We found that only 50% of the ECG tracings demonstrate morphological changes during BI. In 12 of 16 patients (75%) the PS distribution was qualitatively changed during BI. We conclude that such a change implies of a nonlinear deterministic feature of the system underlying the electrical signal of the human heart.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"28 1","pages":"413-416"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74567036","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}
S. Narayanaswamy, E. Berbari, P. Lander, R. Lazzara
Selective beat signal averaging and spectral analysis were implemented to identify whether reentry, triggered activity or parasystole is the mechanism of the isolated premature ventricular contraction (PVC). 2-hour, high resolution ECG recordings were digitally obtained from 9 patients with frequent PVCs (>250/hr). For reentry, in 7/9 patients with a positive average for late potentials (LP) there were no changes of LP in sinus beats before and after PVCs. However, changes in the T/U waves in the difference waveform between the pre-PVC beat and its precedent beat (in 2/9 patients), and their T/U wave amplitudes (in 9/9 patients, mean amplitude difference of 0.0269 mV) implied a triggered activity, mechanism. Also, significant periodicities in PVC interval series and low correlation between sinus and PVC intervals (in 9/9 patients), suggested a parasystolic mechanism. Based on the limited data set, triggered activity and parasystole may be significant PVC mechanisms while reentry may not.<>
{"title":"Selective beat signal averaging and spectral analysis of beat intervals to determine the mechanisms of premature ventricular contractions","authors":"S. Narayanaswamy, E. Berbari, P. Lander, R. Lazzara","doi":"10.1109/CIC.1993.378499","DOIUrl":"https://doi.org/10.1109/CIC.1993.378499","url":null,"abstract":"Selective beat signal averaging and spectral analysis were implemented to identify whether reentry, triggered activity or parasystole is the mechanism of the isolated premature ventricular contraction (PVC). 2-hour, high resolution ECG recordings were digitally obtained from 9 patients with frequent PVCs (>250/hr). For reentry, in 7/9 patients with a positive average for late potentials (LP) there were no changes of LP in sinus beats before and after PVCs. However, changes in the T/U waves in the difference waveform between the pre-PVC beat and its precedent beat (in 2/9 patients), and their T/U wave amplitudes (in 9/9 patients, mean amplitude difference of 0.0269 mV) implied a triggered activity, mechanism. Also, significant periodicities in PVC interval series and low correlation between sinus and PVC intervals (in 9/9 patients), suggested a parasystolic mechanism. Based on the limited data set, triggered activity and parasystole may be significant PVC mechanisms while reentry may not.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"31 1","pages":"81-84"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78733764","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}
A simple tube model of the ventriculo-arterial system is proposed in order to study the relationship between arterial mechanical properties and pressure waveforms. In this model, the arterial system is regarded as a tube with a lumped reflecting site at the distal end and the ventricle (systole) or the aortic valve (diastole) at the proximal end. The propagation of waves is determined by arterial mechanical properties, e.g. reflection coefficients, wave propagation velocity and the effective length of the arterial system. Blood pressure waves in the proximal brachiocephalic artery of the rabbit were recorded and experimental observations were compared with waves simulated from a computer program. Results show that this semiquantitative model illustrates the relationship between arterial mechanical properties and pressure waveforms, and also the effect of arterial mechanics on the left ventricular performance.<>
{"title":"Study of arterial pressure waves using a simple tube model of the ventriculo-arterial system","authors":"Chen-Chin Lee, R. Mark","doi":"10.1109/CIC.1993.378371","DOIUrl":"https://doi.org/10.1109/CIC.1993.378371","url":null,"abstract":"A simple tube model of the ventriculo-arterial system is proposed in order to study the relationship between arterial mechanical properties and pressure waveforms. In this model, the arterial system is regarded as a tube with a lumped reflecting site at the distal end and the ventricle (systole) or the aortic valve (diastole) at the proximal end. The propagation of waves is determined by arterial mechanical properties, e.g. reflection coefficients, wave propagation velocity and the effective length of the arterial system. Blood pressure waves in the proximal brachiocephalic artery of the rabbit were recorded and experimental observations were compared with waves simulated from a computer program. Results show that this semiquantitative model illustrates the relationship between arterial mechanical properties and pressure waveforms, and also the effect of arterial mechanics on the left ventricular performance.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"36 1","pages":"771-774"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79007656","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}
A. Macerata, M. Fusilli, F. Conforti, M. Niccolai, H. Emdin, M. Trivella, C. Marchesi
Frequency domain analysis by power spectrum density (PSD) estimate has proven to be an effective method of investigation for studying the influence of the automatic nervous system on the systemic and coronary hemodynamics. Since the problem is intrinsically multichannel it should be studied by some proper multichannel PSD estimates. Parametric autoregressive spectral methods were used and in particular the Nuttal-Strand algorithm which guarantees good frequency resolution, even in narrow time window, with low bias and low variance estimate. As real time performance is highly desirable for immediate monitoring of pathophysiological features evolution, both during human exercise tests and in animal experiments, the authors developed a system for real time multichannel spectral estimate. The system delegates the heavy computing of PSD estimate to a specialized digital signal processing board and offers a combination of visual panels for instantaneous checking of signals, parameters and spectral envelopes.<>
{"title":"Real time estimation of multichannel power spectrum density for variability analysis of the cardiovascular system","authors":"A. Macerata, M. Fusilli, F. Conforti, M. Niccolai, H. Emdin, M. Trivella, C. Marchesi","doi":"10.1109/CIC.1993.378400","DOIUrl":"https://doi.org/10.1109/CIC.1993.378400","url":null,"abstract":"Frequency domain analysis by power spectrum density (PSD) estimate has proven to be an effective method of investigation for studying the influence of the automatic nervous system on the systemic and coronary hemodynamics. Since the problem is intrinsically multichannel it should be studied by some proper multichannel PSD estimates. Parametric autoregressive spectral methods were used and in particular the Nuttal-Strand algorithm which guarantees good frequency resolution, even in narrow time window, with low bias and low variance estimate. As real time performance is highly desirable for immediate monitoring of pathophysiological features evolution, both during human exercise tests and in animal experiments, the authors developed a system for real time multichannel spectral estimate. The system delegates the heavy computing of PSD estimate to a specialized digital signal processing board and offers a combination of visual panels for instantaneous checking of signals, parameters and spectral envelopes.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"38 1","pages":"475-478"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79033736","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}
In order to enhance early diagnosis especially of ischemic disease, a new ambulatory ECG mapping system has been developed. We present the design and development of the integrated software environment for ambulatory ECG mapping. The considerations involved in the software design are discussed and a menu-driven, multi-window integrated software structure with on-line help has been produced. By means of function decomposition, the system software is divided into three independent modules which afford various facilities for the initialization of the ambulatory recorder before monitoring, replaying and analysis of the acquired long-term ECG data, and report generation. By adopting various software design techniques, high performance is achieved in terms of adaptability, clarity, interaction, efficiency and reliability.<>
{"title":"An integrated software environment for ambulatory ECG mapping","authors":"X. Huang, M. English, R. Vincent, J. Lewis","doi":"10.1109/CIC.1993.378396","DOIUrl":"https://doi.org/10.1109/CIC.1993.378396","url":null,"abstract":"In order to enhance early diagnosis especially of ischemic disease, a new ambulatory ECG mapping system has been developed. We present the design and development of the integrated software environment for ambulatory ECG mapping. The considerations involved in the software design are discussed and a menu-driven, multi-window integrated software structure with on-line help has been produced. By means of function decomposition, the system software is divided into three independent modules which afford various facilities for the initialization of the ambulatory recorder before monitoring, replaying and analysis of the acquired long-term ECG data, and report generation. By adopting various software design techniques, high performance is achieved in terms of adaptability, clarity, interaction, efficiency and reliability.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"73 1","pages":"491-494"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80525320","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}
D. Assanelli, L. Cazzamalli, M. Stambini, M. Poeta
ECG computerized analysis nowadays needs homogeneous standardized reading protocol to provide clinicians reliable diagnostic and prognostic help and allow communication between different cardiological hosts and between cardiological intensive care units, homes, ambulances or peripheral medical emergency structures. SCP protocol of the OEDIPE project solved many of these problems. In the past few years the authors have developed a prototype expert system called ERIC for diagnostic and prognostic use in patients with chest pain so as to overcome many intrinsic limitations of ECG. The system utilizes for these purposes not only ECG analysis according to SCP-protocol criteria, but also chest pain characteristics analysis and risk profile estimation. Thanks to this data integration, the system is more accurate than ECG alone in the diagnosis of chest pain in both normal and diseased patients.<>
{"title":"Correct diagnosis of chest pain by an integrated expert system","authors":"D. Assanelli, L. Cazzamalli, M. Stambini, M. Poeta","doi":"10.1109/CIC.1993.378374","DOIUrl":"https://doi.org/10.1109/CIC.1993.378374","url":null,"abstract":"ECG computerized analysis nowadays needs homogeneous standardized reading protocol to provide clinicians reliable diagnostic and prognostic help and allow communication between different cardiological hosts and between cardiological intensive care units, homes, ambulances or peripheral medical emergency structures. SCP protocol of the OEDIPE project solved many of these problems. In the past few years the authors have developed a prototype expert system called ERIC for diagnostic and prognostic use in patients with chest pain so as to overcome many intrinsic limitations of ECG. The system utilizes for these purposes not only ECG analysis according to SCP-protocol criteria, but also chest pain characteristics analysis and risk profile estimation. Thanks to this data integration, the system is more accurate than ECG alone in the diagnosis of chest pain in both normal and diseased patients.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"58 1","pages":"759-762"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75434490","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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