The effect of spatial orientation of the X-ray gantry on the geometric image distortion caused by the image intensifier (II) is assessed. Variations in absolute positions up to 0.6 mm (14 cm II size), 1.1 mm (17 cm), and 2.8 mm (27 cm) are found for the used Hicor X-ray system. The pixel size varies up to 0.8% (14 cm), 1.1% (17 cm), and 2.3% (27 cm). It is concluded that for accurate quantitative coronary angiography and 3D reconstructions it is necessary to measure the distortion and to correct for it at each of the used orientations.<>
评估了x射线龙门的空间取向对图像增强器(II)引起的几何图像畸变的影响。在使用的Hicor x射线系统中，绝对位置的变化可达0.6 mm (14 cm II尺寸)，1.1 mm (17 cm)和2.8 mm (27 cm)。像素大小可达0.8%(14厘米)、1.1%(17厘米)和2.3%(27厘米)。由此得出结论，为了准确定量冠脉造影和三维重建，有必要在每个使用的方向上测量畸变并对其进行校正。
{"title":"Effect of spatial orientation on the image-intensifier distortion in quantitative coronary angiography","authors":"E. Gronenschild","doi":"10.1109/CIC.1993.378332","DOIUrl":"https://doi.org/10.1109/CIC.1993.378332","url":null,"abstract":"The effect of spatial orientation of the X-ray gantry on the geometric image distortion caused by the image intensifier (II) is assessed. Variations in absolute positions up to 0.6 mm (14 cm II size), 1.1 mm (17 cm), and 2.8 mm (27 cm) are found for the used Hicor X-ray system. The pixel size varies up to 0.8% (14 cm), 1.1% (17 cm), and 2.3% (27 cm). It is concluded that for accurate quantitative coronary angiography and 3D reconstructions it is necessary to measure the distortion and to correct for it at each of the used orientations.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"56 1","pages":"595-598"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83924701","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 report on the development and application of automated spectrophotometry for regional blood flow measurement using the coloured microsphere (CM) dye-extraction technique. A software program running under Microsoft Windows 3.1 was written to simultaneously control an autosampler, sipper pump, pressure valves and spectrophotometer with an exclusively designed small-volume flow-cell. The system allowed consecutive measurements of over 200 tissue samples in volumes as small as 40 /spl mu/L without any attendance. The system was validated in eight chronically instrumented dogs. A comparison between the advanced CM technique and the standard radionuclide microspheres method demonstrated a strong correlation for blood flows to various organs in awake animals. The system proved to be a reliable, user-friendly and time-saving application for the CM dye-extraction technique.<>
本文报道了彩色微球(CM)染料提取技术在区域血流量测量中的应用。在Microsoft Windows 3.1下编写了一个软件程序，用于同时控制一个专门设计的小体积流动池的自动进样器、小泵、压力阀和分光光度计。该系统允许连续测量200多个组织样品，体积小至40 /spl mu/L，无需任何人员。该系统在8只长期使用仪器的狗身上进行了验证。先进的CM技术与标准的放射性核素微球方法的比较表明，清醒动物各器官的血流具有很强的相关性。该系统被证明是一种可靠的、用户友好的、节省时间的CM染料提取技术应用。
{"title":"Measurement of organ blood flow with coloured microspheres: a first time-saving improvement using automated spectrophotometry","authors":"W. Wieland, P. Wouters, H. Van Aken, W. Flameng","doi":"10.1109/CIC.1993.378308","DOIUrl":"https://doi.org/10.1109/CIC.1993.378308","url":null,"abstract":"The authors report on the development and application of automated spectrophotometry for regional blood flow measurement using the coloured microsphere (CM) dye-extraction technique. A software program running under Microsoft Windows 3.1 was written to simultaneously control an autosampler, sipper pump, pressure valves and spectrophotometer with an exclusively designed small-volume flow-cell. The system allowed consecutive measurements of over 200 tissue samples in volumes as small as 40 /spl mu/L without any attendance. The system was validated in eight chronically instrumented dogs. A comparison between the advanced CM technique and the standard radionuclide microspheres method demonstrated a strong correlation for blood flows to various organs in awake animals. The system proved to be a reliable, user-friendly and time-saving application for the CM dye-extraction technique.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"24 1","pages":"691-694"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82963985","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}
X. Xu, T. Griffith, M. Collins, C.J.H. Jones, Y. Tardy
A coupled treatment of blood/arterial wall interactions is presented here. The model solves three different types of equations: (1) the full time-dependent Navier-Stokes equations governing the flow of blood, (2) the linear-elastic small-displacement stress equations for the arterial wall, and (3) the mesh displacement equations. These equations are discretised using the Galerkin finite element method. The coupled model is able to predict the time-dependent displacement and stress fields within the solid wall, as well as the full flow field. To demonstrate the validity of the approach, a number of sample calculations have been performed showing good agreement with available analytical solutions. The model is then applied to physiologically realistic arterial flow situations.<>
{"title":"Coupled modelling of blood flow and arterial wall interactions by the finite element method","authors":"X. Xu, T. Griffith, M. Collins, C.J.H. Jones, Y. Tardy","doi":"10.1109/CIC.1993.378309","DOIUrl":"https://doi.org/10.1109/CIC.1993.378309","url":null,"abstract":"A coupled treatment of blood/arterial wall interactions is presented here. The model solves three different types of equations: (1) the full time-dependent Navier-Stokes equations governing the flow of blood, (2) the linear-elastic small-displacement stress equations for the arterial wall, and (3) the mesh displacement equations. These equations are discretised using the Galerkin finite element method. The coupled model is able to predict the time-dependent displacement and stress fields within the solid wall, as well as the full flow field. To demonstrate the validity of the approach, a number of sample calculations have been performed showing good agreement with available analytical solutions. The model is then applied to physiologically realistic arterial flow situations.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"88 1","pages":"687-690"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83840497","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}
P. Vandervoort, N. Greenberg, P. McCarthy, J.D. Thomas
The assessment of diastolic function currently requires the measurement of intracardiac pressures. Although characteristic pulsed Doppler velocity spectra have been described for a few cardiac diseases, it is only an indirect measure of diastolic function. Color Doppler M-mode measurements of blood passing from the atrium to the ventricle may allow one to investigate global (transmitral) and local (intraventricular) pressure gradients, associated with ventricular relaxation. In the study reported the authors investigate the feasibility and the accuracy of calculating transmitral filling gradients from color Doppler M-mode velocities.<>
{"title":"Estimation of left ventricular filling gradients using digital analysis of color Doppler M-mode velocities","authors":"P. Vandervoort, N. Greenberg, P. McCarthy, J.D. Thomas","doi":"10.1109/CIC.1993.378446","DOIUrl":"https://doi.org/10.1109/CIC.1993.378446","url":null,"abstract":"The assessment of diastolic function currently requires the measurement of intracardiac pressures. Although characteristic pulsed Doppler velocity spectra have been described for a few cardiac diseases, it is only an indirect measure of diastolic function. Color Doppler M-mode measurements of blood passing from the atrium to the ventricle may allow one to investigate global (transmitral) and local (intraventricular) pressure gradients, associated with ventricular relaxation. In the study reported the authors investigate the feasibility and the accuracy of calculating transmitral filling gradients from color Doppler M-mode velocities.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"41 1","pages":"293-296"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83212026","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}
W. Wunderlich, T. Linderer, B. Backs, F. Fischer, J. Noering, R. Schroeder
Optimum geometric edge detection in quantitative coronary arteriography (QCA) is determined by the accuracy of measurements of known phantom diameters. The authors optimized the edge detection for different calibration methods, diameter ranges, accuracy measures and performance strategies. They found, that the optimization process itself is ill-defined, depending on the calibration method used, the included range of small diameters and the accuracy measure. For detectability of diameter changes accuracy-optimized edge detection is inferior to precision-optimum approach. The optimization of both, accuracy and precision can only be achieved with a precision-optimum approach and diameter correction.<>
{"title":"Optimizing edge detection in quantitative coronary arteriography: problems and proposals","authors":"W. Wunderlich, T. Linderer, B. Backs, F. Fischer, J. Noering, R. Schroeder","doi":"10.1109/CIC.1993.378335","DOIUrl":"https://doi.org/10.1109/CIC.1993.378335","url":null,"abstract":"Optimum geometric edge detection in quantitative coronary arteriography (QCA) is determined by the accuracy of measurements of known phantom diameters. The authors optimized the edge detection for different calibration methods, diameter ranges, accuracy measures and performance strategies. They found, that the optimization process itself is ill-defined, depending on the calibration method used, the included range of small diameters and the accuracy measure. For detectability of diameter changes accuracy-optimized edge detection is inferior to precision-optimum approach. The optimization of both, accuracy and precision can only be achieved with a precision-optimum approach and diameter correction.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"1 1","pages":"583-586"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83326539","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}
C. Bull, M. Chiogna, R. Franklin, D. Spiegelhalter
Classification trees provide an attractively transparent discrimination technique and may be derived either from expert opinion or from data analysis. The authors considered a real and complex problem concerning the diagnosis of babies with suspected congenital heart disease into one of 27 classes. A full loss matrix for all possible misclassifications was obtained from clinical assessments. A tree derived from expert opinion was compared with trees derived from analysis of 571 past cases both for the full problem and for a subset of 6 diseases. Automatic methods for tree creation had problems with rare diseases. Inclusion of 'costs of misclassification' feedback on the training dataset improved the performance of data derived trees though they were generally outperformed by the expert tree.<>
{"title":"Expert derived automatically generated classification trees: an example from pediatric cardiology","authors":"C. Bull, M. Chiogna, R. Franklin, D. Spiegelhalter","doi":"10.1109/CIC.1993.378465","DOIUrl":"https://doi.org/10.1109/CIC.1993.378465","url":null,"abstract":"Classification trees provide an attractively transparent discrimination technique and may be derived either from expert opinion or from data analysis. The authors considered a real and complex problem concerning the diagnosis of babies with suspected congenital heart disease into one of 27 classes. A full loss matrix for all possible misclassifications was obtained from clinical assessments. A tree derived from expert opinion was compared with trees derived from analysis of 571 past cases both for the full problem and for a subset of 6 diseases. Automatic methods for tree creation had problems with rare diseases. Inclusion of 'costs of misclassification' feedback on the training dataset improved the performance of data derived trees though they were generally outperformed by the expert tree.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"34 1","pages":"217-220"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90696172","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 new method is developed for reducing signal-overlapping noise in the standard electrocardiogram, which has so far been difficult with a traditional filter based on the frequency method. The new method, called signal decomposition method, first separates the input signal into a noise-free part and a noise-overlapping part with a zero-phase low-pass filter. It then restores the signal components from the noise-overlapping part and adds the signal components to the noise-free part so as to eliminate distortion of the original signal. An experimental study with clinical ECG data shows that this method is very effective in reducing signal-overlapping noise and power interference, with little signal distortion.<>
{"title":"A new method for reducing signal-overlapping noise in standard electrocardiogram","authors":"D. Wei, E. Harasawa, H. Harada, H. Hosaka","doi":"10.1109/CIC.1993.378365","DOIUrl":"https://doi.org/10.1109/CIC.1993.378365","url":null,"abstract":"A new method is developed for reducing signal-overlapping noise in the standard electrocardiogram, which has so far been difficult with a traditional filter based on the frequency method. The new method, called signal decomposition method, first separates the input signal into a noise-free part and a noise-overlapping part with a zero-phase low-pass filter. It then restores the signal components from the noise-overlapping part and adds the signal components to the noise-free part so as to eliminate distortion of the original signal. An experimental study with clinical ECG data shows that this method is very effective in reducing signal-overlapping noise and power interference, with little signal distortion.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"48 1","pages":"795-798"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90116627","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 relationship between strength of short-term whole body autoregulation and peripheral resistance in the reference state (initial resistance) was investigated in dogs (n=9) and cats (n=18) after abolishing baroreflex activity. Aortic and venous pressure and aortic flow the authors remeasured in the reference state and one to three minutes after partial vena cava occlusions. After cardiac output and peripheral resistance were normalised for body weight, autoregulation resistance gain (G/sub ra/) was estimated from the experimental data. The relationship between values of G/sub ra/ and the corresponding values of initial resistance was approximated by a straight line (r=0.9) with positive slope. This result indicates that the higher the resistance in the reference state, the stronger autoregulation will be.<>
{"title":"Influence of initial resistance on gain of short-term systemic autoregulation","authors":"R. Burattini, P. Borgdorff, N. Westerhof","doi":"10.1109/CIC.1993.378314","DOIUrl":"https://doi.org/10.1109/CIC.1993.378314","url":null,"abstract":"The relationship between strength of short-term whole body autoregulation and peripheral resistance in the reference state (initial resistance) was investigated in dogs (n=9) and cats (n=18) after abolishing baroreflex activity. Aortic and venous pressure and aortic flow the authors remeasured in the reference state and one to three minutes after partial vena cava occlusions. After cardiac output and peripheral resistance were normalised for body weight, autoregulation resistance gain (G/sub ra/) was estimated from the experimental data. The relationship between values of G/sub ra/ and the corresponding values of initial resistance was approximated by a straight line (r=0.9) with positive slope. This result indicates that the higher the resistance in the reference state, the stronger autoregulation will be.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"28 1","pages":"667-669"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75892603","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. Locati-Heilbron, P. Maison-Blanche, F. Bozza, P. Dejode, P. Coumel
Stereotyped "short-long" templates have been described to precede the spontaneous onset of ventricular arrhythmias. Individual "short-long" cycle length sequences can be modelized and implemented to digitized Holter recordings, in order to detect how often a specific template is followed by ventricular arrhythmias. Thus, the probability of individual "short-long" templates to be followed by ventricular arrhythmias can be computed. Therefore, the quantitative scanning of digitized Holter recordings for individual-specific cycle length sequences can be viewed as new "non-invasive electrophysiologic test" exploring the individual cycle length determinants of ventricular arrhythmias.<>
{"title":"Probability of ventricular arrhythmias following stereotyped short-long sequences: a computerized analysis of digitized dynamic ECG recordings","authors":"E. Locati-Heilbron, P. Maison-Blanche, F. Bozza, P. Dejode, P. Coumel","doi":"10.1109/CIC.1993.378345","DOIUrl":"https://doi.org/10.1109/CIC.1993.378345","url":null,"abstract":"Stereotyped \"short-long\" templates have been described to precede the spontaneous onset of ventricular arrhythmias. Individual \"short-long\" cycle length sequences can be modelized and implemented to digitized Holter recordings, in order to detect how often a specific template is followed by ventricular arrhythmias. Thus, the probability of individual \"short-long\" templates to be followed by ventricular arrhythmias can be computed. Therefore, the quantitative scanning of digitized Holter recordings for individual-specific cycle length sequences can be viewed as new \"non-invasive electrophysiologic test\" exploring the individual cycle length determinants of ventricular arrhythmias.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"17 1","pages":"883-886"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73939695","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. Veress, J. Cornhill, Kimerly A. Powell, E. E. Herderick, James D. Thomas
2-D mathematical models of the coronary walls have been developed based on actual plaque morphology from a multi-center study of coronary disease (Pathological Determinants of Atherosclerosis in Youths, PDAY). The probability of lipid maps were used to define a typical lesion's physical dimensions for four age ranges. Under physiological loading from intra-arterial pressure, the resulting intramural stress distributions were quantified as a function of patient age. The area of highest stress in the 15-19 year group was shifted from the healthy wall opposite the lesion to the area where the normal intima is adjacent to the plaque cap and increased with age. The age related development of atherosclerosis leads to a predictable increase in localized wall stress, which may predispose a plaque to rupture.<>
{"title":"Finite element modeling of atherosclerotic plaque","authors":"A. Veress, J. Cornhill, Kimerly A. Powell, E. E. Herderick, James D. Thomas","doi":"10.1109/CIC.1993.378366","DOIUrl":"https://doi.org/10.1109/CIC.1993.378366","url":null,"abstract":"2-D mathematical models of the coronary walls have been developed based on actual plaque morphology from a multi-center study of coronary disease (Pathological Determinants of Atherosclerosis in Youths, PDAY). The probability of lipid maps were used to define a typical lesion's physical dimensions for four age ranges. Under physiological loading from intra-arterial pressure, the resulting intramural stress distributions were quantified as a function of patient age. The area of highest stress in the 15-19 year group was shifted from the healthy wall opposite the lesion to the area where the normal intima is adjacent to the plaque cap and increased with age. The age related development of atherosclerosis leads to a predictable increase in localized wall stress, which may predispose a plaque to rupture.<<ETX>>","PeriodicalId":20445,"journal":{"name":"Proceedings of Computers in Cardiology Conference","volume":"37 1","pages":"791-794"},"PeriodicalIF":0.0,"publicationDate":"1993-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84247013","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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