Pub Date : 1900-01-01DOI: 10.1109/IEMBS.1988.94646
A. Cappello, G. Avanzolini
Three viscoelastic models of the left-ventricular (LV) pumping function are proposed and compared with the classical elastance-resistance description starting from data measured on dogs: isovolumic pressure at a given preload together with a series of LV pressure and outflow curves with graded aortic occlusions. The comparison criterion takes into account descriptive ability, robustness of the estimates, and their physical interpretation. The analysis confirms the presence of both activation and deactivation phenomena. The dependence of stiffness and resistance on afterload agrees with known myocardial features and supports the local validity of the proposed models.<>
{"title":"Descriptive ability of three local left ventricle pump models","authors":"A. Cappello, G. Avanzolini","doi":"10.1109/IEMBS.1988.94646","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94646","url":null,"abstract":"Three viscoelastic models of the left-ventricular (LV) pumping function are proposed and compared with the classical elastance-resistance description starting from data measured on dogs: isovolumic pressure at a given preload together with a series of LV pressure and outflow curves with graded aortic occlusions. The comparison criterion takes into account descriptive ability, robustness of the estimates, and their physical interpretation. The analysis confirms the presence of both activation and deactivation phenomena. The dependence of stiffness and resistance on afterload agrees with known myocardial features and supports the local validity of the proposed models.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117189116","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.95353
N. Carnevale, T. Woolf, G. M. Shepherd
Hypotheses of neuronal functions that invoke realistic anatomical and biophysical properties must be confirmed by quantitative simulation. Most simulators are unable to emulate biophysical phenomena such as time- and voltage-dependent (active) conductances directly. The authors report how special features of SABER, a new general-purpose simulator, facilitated the modeling of active conductances.<>
{"title":"Simulating neurons with SABER","authors":"N. Carnevale, T. Woolf, G. M. Shepherd","doi":"10.1109/IEMBS.1988.95353","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.95353","url":null,"abstract":"Hypotheses of neuronal functions that invoke realistic anatomical and biophysical properties must be confirmed by quantitative simulation. Most simulators are unable to emulate biophysical phenomena such as time- and voltage-dependent (active) conductances directly. The authors report how special features of SABER, a new general-purpose simulator, facilitated the modeling of active conductances.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120972397","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.94634
D. Sideris
Reducing the venous return in proportion to the blood pressure (BP) can prevent abnormal elevations of the latter. The possibility of applying this principle is examined for either permanent or acute control of a high BP. An implantable extravascular device based on this principle was applied in four dogs. One animal survived up to the 12th day and another was sacrificed in the 6th week. An external intravascular version was applied in four dogs. After setting the average BP to around 100 mm Hg, the device mitigated a metaraminol-induced BP elevation from about 240 to about 150 mm Hg without reducing BP when the hypertensive stimulus subsided.<>
{"title":"Feedback control of blood pressure evaluations by a simple mechanical device","authors":"D. Sideris","doi":"10.1109/IEMBS.1988.94634","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94634","url":null,"abstract":"Reducing the venous return in proportion to the blood pressure (BP) can prevent abnormal elevations of the latter. The possibility of applying this principle is examined for either permanent or acute control of a high BP. An implantable extravascular device based on this principle was applied in four dogs. One animal survived up to the 12th day and another was sacrificed in the 6th week. An external intravascular version was applied in four dogs. After setting the average BP to around 100 mm Hg, the device mitigated a metaraminol-induced BP elevation from about 240 to about 150 mm Hg without reducing BP when the hypertensive stimulus subsided.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120976757","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.95047
J. Heller, W. McMahan, N. Bryan
A computer system has been developed to automate the in-vivo evaluation of amperometric electrochemical sensors in unanesthetized, tethered rabbits. Subcutaneous glucose, oxygen and temperature are monitored. Continuous, simultaneous monitoring of eight animals for several weeks is possible. Data collection rates are adjustable up to once every five minutes. Blood sample withdrawal and intravenous injection are carried out manually through a remote access port with computer prompting. Blood chemistry results are entered via keyboard and merged with the database from the sensor outputs. This multiple, parallel testing with minimal personnel intervention has made in-vivo statistical analysis of experimental electrochemical sensors feasible.<>
{"title":"An in-vitro test system for electrochemical sensors","authors":"J. Heller, W. McMahan, N. Bryan","doi":"10.1109/IEMBS.1988.95047","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.95047","url":null,"abstract":"A computer system has been developed to automate the in-vivo evaluation of amperometric electrochemical sensors in unanesthetized, tethered rabbits. Subcutaneous glucose, oxygen and temperature are monitored. Continuous, simultaneous monitoring of eight animals for several weeks is possible. Data collection rates are adjustable up to once every five minutes. Blood sample withdrawal and intravenous injection are carried out manually through a remote access port with computer prompting. Blood chemistry results are entered via keyboard and merged with the database from the sensor outputs. This multiple, parallel testing with minimal personnel intervention has made in-vivo statistical analysis of experimental electrochemical sensors feasible.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121003604","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.95188
S. Weiss, C. Dawson, I. Kapouleas, R. Nozik, D. Skorich, J. Ostroff
In developing countries, blindness often results from a lack of proper treatment for relatively simple eye problems. Specialist medical care is not readily available, and patients are seen by frontline health workers. To assist primary health workers in the management of common and potentially blinding eye disorders, the authors have developed a computer program for a hand-held computer that incorporates a set of guidelines for diagnosis and treatment or referral to a more distant medical center. They review the progress made in implementing, testing, and disseminating this program. They also describe progress in developing another program for automating laboratory test selection in uveitis.<>
{"title":"Rule-based diagnostic decision aids for common eye problems","authors":"S. Weiss, C. Dawson, I. Kapouleas, R. Nozik, D. Skorich, J. Ostroff","doi":"10.1109/IEMBS.1988.95188","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.95188","url":null,"abstract":"In developing countries, blindness often results from a lack of proper treatment for relatively simple eye problems. Specialist medical care is not readily available, and patients are seen by frontline health workers. To assist primary health workers in the management of common and potentially blinding eye disorders, the authors have developed a computer program for a hand-held computer that incorporates a set of guidelines for diagnosis and treatment or referral to a more distant medical center. They review the progress made in implementing, testing, and disseminating this program. They also describe progress in developing another program for automating laboratory test selection in uveitis.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121268359","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.95204
S. Curry, S. Baumrind
The authors have developed a real-time mandibular motion analysis system. A nonrestraining extraoral harness carries a set of light-emitting diodes (LEDs), whose movements are detected by photodiode detectors interfaced to a personal computer. Mandibular motions are computed rigorously in three dimensions. Movements at various points on the mandible are displayed on a graphics monitor. The system will find application in the characterization of temporo-mandibular joint (TMJ) disfunction and in the determination of changes in functional jaw movements after orthodontic treatment and orthognathic surgery. Recent developments have included an increase in accuracy, a hardware upgrade for greater data analysis speed, and the addition of a free-hand pointer for the identification of anatomic features of interest to the user.<>
{"title":"Realtime mandibular motion analysis-recent developments","authors":"S. Curry, S. Baumrind","doi":"10.1109/IEMBS.1988.95204","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.95204","url":null,"abstract":"The authors have developed a real-time mandibular motion analysis system. A nonrestraining extraoral harness carries a set of light-emitting diodes (LEDs), whose movements are detected by photodiode detectors interfaced to a personal computer. Mandibular motions are computed rigorously in three dimensions. Movements at various points on the mandible are displayed on a graphics monitor. The system will find application in the characterization of temporo-mandibular joint (TMJ) disfunction and in the determination of changes in functional jaw movements after orthodontic treatment and orthognathic surgery. Recent developments have included an increase in accuracy, a hardware upgrade for greater data analysis speed, and the addition of a free-hand pointer for the identification of anatomic features of interest to the user.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127106260","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.94414
C.T. Chittenden, C. S. Weaver
A novel ambulatory blood pressure monitor shows high accuracy even in the presence of an artifact. Signal processing algorithms separate true blood-pressure signals from noise induced by the environment or by subject motion. The algorithms adaptively utilize timing information obtained from ECG and Korotkov sound signals as well as Korotkov sound magnitude. A clinical study verified highly accurate results in an exercise stress testing environment. An independent study verified that the monitor produces highly accurate results in stress test and ambulatory environments.<>
{"title":"Blood pressure measurement artifact rejection in noisy environments","authors":"C.T. Chittenden, C. S. Weaver","doi":"10.1109/IEMBS.1988.94414","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94414","url":null,"abstract":"A novel ambulatory blood pressure monitor shows high accuracy even in the presence of an artifact. Signal processing algorithms separate true blood-pressure signals from noise induced by the environment or by subject motion. The algorithms adaptively utilize timing information obtained from ECG and Korotkov sound signals as well as Korotkov sound magnitude. A clinical study verified highly accurate results in an exercise stress testing environment. An independent study verified that the monitor produces highly accurate results in stress test and ambulatory environments.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127133450","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.94687
L. Roa, T. Gómez-Cía, A. Cantero
The authors present a comparative study of the responses of burn patients to different reanimation treatments, one of them designed by experimental and clinical methods, and another one (BET) designed by digital simulation in a burn injury simulator. The alterations of the capillary dynamics and the therapeutics after the burn injury are analyzed with the mathematical model. The optimum treatment described in this report was superior in all trials. The authors conclude that BET can be used advantageously in burn patient shock stage in order to minimize complications.<>
{"title":"Digital simulation of the burn patient shock-design of an optimum reanimation treatment","authors":"L. Roa, T. Gómez-Cía, A. Cantero","doi":"10.1109/IEMBS.1988.94687","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94687","url":null,"abstract":"The authors present a comparative study of the responses of burn patients to different reanimation treatments, one of them designed by experimental and clinical methods, and another one (BET) designed by digital simulation in a burn injury simulator. The alterations of the capillary dynamics and the therapeutics after the burn injury are analyzed with the mathematical model. The optimum treatment described in this report was superior in all trials. The authors conclude that BET can be used advantageously in burn patient shock stage in order to minimize complications.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127219594","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.94543
D. Saloner
The inherent sensitivity of magnetic resonance imaging to motion makes it particularly well-suited as a noninvasive flow measurement modality. A pulse sequence which labels moving material by subjecting it to a pulse that inverts the longitudinal magnetization is discussed. Repeated application of this pulse produces a steady-state distribution of magnetization reflecting the history of material motion through the region of excitation. The sequence produces a strong suppression of signal from stationary material enhancing the dynamic range available to signal from moving material. In particular, angiographic-type projection images of flow in human subjects have been obtained with gated acquisition. These images display boli of tagged blood moving in arteries and veins. The boli are displaced in a direction and through a distance reflecting the temporal and spatial variation of velocity in the vessel.<>
{"title":"Flow velocity measurements for pulsatile flow","authors":"D. Saloner","doi":"10.1109/IEMBS.1988.94543","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94543","url":null,"abstract":"The inherent sensitivity of magnetic resonance imaging to motion makes it particularly well-suited as a noninvasive flow measurement modality. A pulse sequence which labels moving material by subjecting it to a pulse that inverts the longitudinal magnetization is discussed. Repeated application of this pulse produces a steady-state distribution of magnetization reflecting the history of material motion through the region of excitation. The sequence produces a strong suppression of signal from stationary material enhancing the dynamic range available to signal from moving material. In particular, angiographic-type projection images of flow in human subjects have been obtained with gated acquisition. These images display boli of tagged blood moving in arteries and veins. The boli are displaced in a direction and through a distance reflecting the temporal and spatial variation of velocity in the vessel.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124817595","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 : 1900-01-01DOI: 10.1109/IEMBS.1988.94483
F. Witkowski, P. Penkoske
Management of patients with malignant arrhythmias occurring outside the hospital and the development of clinically applicable systems for internal defibrillation have stimulated interest in the factors influencing cardiac defibrillation. Using a directly coupled (DC) electrode and amplification scheme, the authors have developed a system capable of simultaneous three-dimensional mapping of both the high energy shock field created in the heart by defibrillation electrodes in addition to the mapping of the immediate postshock myocardial activation sequence. Experiments performed in vivo in anesthetized open-chest dogs revealed that successful defibrillation required 100% of the site examined to be depolarized, with the first post defibrillation beat originating in the area of minimum defibrillatory potential.<>
{"title":"Relation of defibrillatory potential minima to post-defibrillatory activation","authors":"F. Witkowski, P. Penkoske","doi":"10.1109/IEMBS.1988.94483","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94483","url":null,"abstract":"Management of patients with malignant arrhythmias occurring outside the hospital and the development of clinically applicable systems for internal defibrillation have stimulated interest in the factors influencing cardiac defibrillation. Using a directly coupled (DC) electrode and amplification scheme, the authors have developed a system capable of simultaneous three-dimensional mapping of both the high energy shock field created in the heart by defibrillation electrodes in addition to the mapping of the immediate postshock myocardial activation sequence. Experiments performed in vivo in anesthetized open-chest dogs revealed that successful defibrillation required 100% of the site examined to be depolarized, with the first post defibrillation beat originating in the area of minimum defibrillatory potential.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125003248","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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