Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.412086
K. Naim, W. Santamore, D. Jaron
A model was developed to study the time-varying relation between regional LV mechanics, local coronary flow and some of the important underlying metabolic factors. The authors' previous LV model was extended to simulate the changes in regional behavior of the heart imposed by modifications in local coronary flow. This was accomplished by quantifying the relation between regional heart metabolism and function. The resulting model is capable of predicting the acute changes in heart function during the development of myocardial ischemia following coronary stenosis.<>
{"title":"A computer simulation of the dynamic interaction between regional coronary flow and LV mechanics","authors":"K. Naim, W. Santamore, D. Jaron","doi":"10.1109/IEMBS.1994.412086","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412086","url":null,"abstract":"A model was developed to study the time-varying relation between regional LV mechanics, local coronary flow and some of the important underlying metabolic factors. The authors' previous LV model was extended to simulate the changes in regional behavior of the heart imposed by modifications in local coronary flow. This was accomplished by quantifying the relation between regional heart metabolism and function. The resulting model is capable of predicting the acute changes in heart function during the development of myocardial ischemia following coronary stenosis.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117069903","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.415147
J. A. Pearce, T. Magnusen
Numerical finite difference method models of bipolar electrosurgical electrode fields reveal non uniform power density patterns corresponding approximately to thermal damage fields observed in histologic sections. Predicted electrode impedance compares favorably with experimentally measured values. The results may be used to predict transient temperature field histories from which damage extent may be estimated.<>
{"title":"Numerical models of bipolar electrode electrosurgical current fields","authors":"J. A. Pearce, T. Magnusen","doi":"10.1109/IEMBS.1994.415147","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415147","url":null,"abstract":"Numerical finite difference method models of bipolar electrosurgical electrode fields reveal non uniform power density patterns corresponding approximately to thermal damage fields observed in histologic sections. Predicted electrode impedance compares favorably with experimentally measured values. The results may be used to predict transient temperature field histories from which damage extent may be estimated.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117253232","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.412020
M.S. Sellberg, M. Vanderploeg
A comprehensive database of 3D geometric models of the human musculoskeletal anatomy has been created along with Virtual Human software that utilizes the models for both biomechanics and computer-aided instruction applications. In addition to the software, results include a lower extremity muscle model for biomechanical and rehabilitation analysis, a lumped set of muscles for rehabilitation controls systems research, an animation of knee motion including deforming muscles, and bone metabolism and muscle ion flux physiology animations for computer-aided instruction.<>
{"title":"Virtual Human: a computer graphics model for biomechanical simulations and computer-aided instruction","authors":"M.S. Sellberg, M. Vanderploeg","doi":"10.1109/IEMBS.1994.412020","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412020","url":null,"abstract":"A comprehensive database of 3D geometric models of the human musculoskeletal anatomy has been created along with Virtual Human software that utilizes the models for both biomechanics and computer-aided instruction applications. In addition to the software, results include a lower extremity muscle model for biomechanical and rehabilitation analysis, a lumped set of muscles for rehabilitation controls systems research, an animation of knee motion including deforming muscles, and bone metabolism and muscle ion flux physiology animations for computer-aided instruction.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115989058","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.411793
H. S. Oster, B. Taccardi, R. Lux, P. Ershler, Y. Rudy
The goal of this work is to demonstrate the ability of electrocardiographic imaging to identify and locate ventricular epicardial pacing sites. Using a dog heart suspended in an electrolytic torso tank, epicardial sites were paced, simulating an ectopic focus. The inverse problem was solved using the measured torso potential data, and the results were evaluated with respect to the measured epicardial data. Pacing sites were located to within one electrode position (1.5 cm), and two sites paced simultaneously were resolved to 2.5 cm.<>
{"title":"Electrocardiographic imaging: evaluating its ability to locate and resolve pacing sites noninvasively","authors":"H. S. Oster, B. Taccardi, R. Lux, P. Ershler, Y. Rudy","doi":"10.1109/IEMBS.1994.411793","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411793","url":null,"abstract":"The goal of this work is to demonstrate the ability of electrocardiographic imaging to identify and locate ventricular epicardial pacing sites. Using a dog heart suspended in an electrolytic torso tank, epicardial sites were paced, simulating an ectopic focus. The inverse problem was solved using the measured torso potential data, and the results were evaluated with respect to the measured epicardial data. Pacing sites were located to within one electrode position (1.5 cm), and two sites paced simultaneously were resolved to 2.5 cm.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"375 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123434151","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.411843
P. Reuze, A. Bruno, E. Le Rumeur
Textural features are compared for the classification of MR muscle images. The objective is to determine which features optimize classification rate using small ROIs. Four classes of textural features are considered: the authors have studied fractal, cooccurrence, higher order statistics and mathematical morphology. The quantitative evaluation of the discrimination power of the features is based on the performance of the classification error rate with a K-nearest neighbor classifier. The results shows that the mathematical morphology features provide the best classification rate on the authors' clinical MR images of healthy and sick muscles.<>
{"title":"Performance evaluation of some textural features for muscle tissue classification","authors":"P. Reuze, A. Bruno, E. Le Rumeur","doi":"10.1109/IEMBS.1994.411843","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411843","url":null,"abstract":"Textural features are compared for the classification of MR muscle images. The objective is to determine which features optimize classification rate using small ROIs. Four classes of textural features are considered: the authors have studied fractal, cooccurrence, higher order statistics and mathematical morphology. The quantitative evaluation of the discrimination power of the features is based on the performance of the classification error rate with a K-nearest neighbor classifier. The results shows that the mathematical morphology features provide the best classification rate on the authors' clinical MR images of healthy and sick muscles.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116880463","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.415285
P. Gascoyne, Y. Huang, M. Hughes, X.-B. Wang, R. Pethig, F.F. Becker
The AC electrokinetics of Friend murine erythroleukemia cells subjected to travelling electric fields were studied as a function of the frequency of applied electrical fields and the results understood through theoretical calculations of field distributions and the resultant dielectrophoretic forces. The authors discuss the application of the field-induced kinetic effects to the spatial separation of different cell types.<>
{"title":"Manipulation of erythroleukemia cells using travelling electric fields","authors":"P. Gascoyne, Y. Huang, M. Hughes, X.-B. Wang, R. Pethig, F.F. Becker","doi":"10.1109/IEMBS.1994.415285","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415285","url":null,"abstract":"The AC electrokinetics of Friend murine erythroleukemia cells subjected to travelling electric fields were studied as a function of the frequency of applied electrical fields and the results understood through theoretical calculations of field distributions and the resultant dielectrophoretic forces. The authors discuss the application of the field-induced kinetic effects to the spatial separation of different cell types.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117215881","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.411870
K. Ramanujan, T. Papathomas, A. Gorea
We have developed a new computational model for texture perception which is physiologically plausible and mimics human performance. Our model tries to simulate the visual processing characteristics by incorporating mechanisms tuned to luminance, orientation, spatial-frequency and color, which are characteristic features of any textural image. We obtained a very good correlation between human performance and our model simulations with various strategic texture patterns. The highlights of our model are incorporation of chromatic mechanisms to treat color images, in addition to grey-level ones, and the extension of the concept of double-opponency beyond color. The model could be utilized in the area of image processing, machine vision and pattern recognition, and scientific visualization.<>
{"title":"A computational model for texture perception with chromatic and achromatic images","authors":"K. Ramanujan, T. Papathomas, A. Gorea","doi":"10.1109/IEMBS.1994.411870","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411870","url":null,"abstract":"We have developed a new computational model for texture perception which is physiologically plausible and mimics human performance. Our model tries to simulate the visual processing characteristics by incorporating mechanisms tuned to luminance, orientation, spatial-frequency and color, which are characteristic features of any textural image. We obtained a very good correlation between human performance and our model simulations with various strategic texture patterns. The highlights of our model are incorporation of chromatic mechanisms to treat color images, in addition to grey-level ones, and the extension of the concept of double-opponency beyond color. The model could be utilized in the area of image processing, machine vision and pattern recognition, and scientific visualization.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"50 14","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120815395","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.412026
C. Ren, P. Tarjan
The effect of magnetic stimulation to a great extent depends on the design of the coil system. We present the characteristics of a novel coil design for electromagnetic stimulation. Based on a mathematical model, we predict improved adjustability and focality than available from coils in clinical use.<>
{"title":"Coil design for adjustable magnetic stimulation","authors":"C. Ren, P. Tarjan","doi":"10.1109/IEMBS.1994.412026","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412026","url":null,"abstract":"The effect of magnetic stimulation to a great extent depends on the design of the coil system. We present the characteristics of a novel coil design for electromagnetic stimulation. Based on a mathematical model, we predict improved adjustability and focality than available from coils in clinical use.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124395317","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.415281
M. Iwasaka, S. Ueno, H. Tsuda
The authors have observed that the fibrinolytic process in strong magnetic fields up to 8 T was enhanced. In this study, they focused on the mechanism of this phenomenon. First, they observed that gradient magnetic fields eroded a fibrin gel in a specific direction. Second, they carried out an experiment to measure concentrations of fibrin in magnetic fields and concluded that redistribution of fibrin polymers concentration occurred in gradient magnetic fields up to 8 T.<>
作者观察到，在高达 8 T 的强磁场中，纤维蛋白溶解过程得到了增强。在这项研究中，他们重点研究了这一现象的机理。首先，他们观察到梯度磁场沿特定方向侵蚀纤维蛋白凝胶。其次，他们进行了一项测量磁场中纤维蛋白浓度的实验，得出的结论是，在高达 8 T 的梯度磁场中，纤维蛋白聚合物浓度发生了重新分布。
{"title":"Fibrinolysis in strong magnetic fields","authors":"M. Iwasaka, S. Ueno, H. Tsuda","doi":"10.1109/IEMBS.1994.415281","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415281","url":null,"abstract":"The authors have observed that the fibrinolytic process in strong magnetic fields up to 8 T was enhanced. In this study, they focused on the mechanism of this phenomenon. First, they observed that gradient magnetic fields eroded a fibrin gel in a specific direction. Second, they carried out an experiment to measure concentrations of fibrin in magnetic fields and concluded that redistribution of fibrin polymers concentration occurred in gradient magnetic fields up to 8 T.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129688812","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}
Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.415269
J. Draheim, J. Cassim
The conformational capabilities of the in situ transmembrane protein bacteriorhodopsin (bR) were studied by mid-IR linear dichroism of purple membrane (PM) films. Illumination of bR, with a Schiff-base bound retinylidene prosthetic group, is usually accompanied by the vectorial translocation of H/sup +/ across the membrane bilayer. In the presence of hydroxylamine HCl however, illumination hydrolyzes the Schiff-base linkage between bR and its retinylidene chromophore (photobleaching). Analysis of the mid-IR linear dichroism of PM indicates: (1) the /spl alpha/-helical segments in bR are oriented nearly parallel to the PM normal; (2) after photobleaching the PM, the /spl alpha/-helical segments of bR are tilted 24/spl deg/ away from the PM normal; (3) after cross-linking PM with dimethyl adipimidate the /spl alpha/-helical segments of bR are tilted 9/spl deg/ away from the PM normal; (4) after cross-linking and photobleaching, the /spl alpha/-helical segments of bR are tilted 30/spl deg/ away from the PM normal.<>
{"title":"Bacteriorhodopsin molecular dynamics: photobleaching and chemical cross-linking","authors":"J. Draheim, J. Cassim","doi":"10.1109/IEMBS.1994.415269","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415269","url":null,"abstract":"The conformational capabilities of the in situ transmembrane protein bacteriorhodopsin (bR) were studied by mid-IR linear dichroism of purple membrane (PM) films. Illumination of bR, with a Schiff-base bound retinylidene prosthetic group, is usually accompanied by the vectorial translocation of H/sup +/ across the membrane bilayer. In the presence of hydroxylamine HCl however, illumination hydrolyzes the Schiff-base linkage between bR and its retinylidene chromophore (photobleaching). Analysis of the mid-IR linear dichroism of PM indicates: (1) the /spl alpha/-helical segments in bR are oriented nearly parallel to the PM normal; (2) after photobleaching the PM, the /spl alpha/-helical segments of bR are tilted 24/spl deg/ away from the PM normal; (3) after cross-linking PM with dimethyl adipimidate the /spl alpha/-helical segments of bR are tilted 9/spl deg/ away from the PM normal; (4) after cross-linking and photobleaching, the /spl alpha/-helical segments of bR are tilted 30/spl deg/ away from the PM normal.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129719414","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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