Pub Date : 1988-11-01DOI: 10.1109/IEMBS.1988.94633
G. Cavelier, A. Gauthier, K. Meier, J. Bohorquez, P. Ibarra
During hypertensive crisis, intensive-care-unit physicians use vasoactive drug infusion in order to diminish the patient's elevated arterial pressure. A controller was designed to automate drug infusion during hypertensive crisis, permitting the lowering and maintenance of arterial pressure at predetermined values. It allows preprogramming of functions and alarms as well as possible supervision by the doctor. Experiments performed with anesthetized dogs were analyzed to obtain identification and validation of a physiological model. The design, simulation, and testing of an original control algorithm resulted in automatic initial identification of dog parameters, automatic setting of appropriate control parameters, and adequate lowering and posterior maintenance of desired arterial pressure level. A compact, self contained, microprocessor-based controller prototype was constructed and is currently under test.<>
{"title":"Automatic controller of arterial pressure","authors":"G. Cavelier, A. Gauthier, K. Meier, J. Bohorquez, P. Ibarra","doi":"10.1109/IEMBS.1988.94633","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94633","url":null,"abstract":"During hypertensive crisis, intensive-care-unit physicians use vasoactive drug infusion in order to diminish the patient's elevated arterial pressure. A controller was designed to automate drug infusion during hypertensive crisis, permitting the lowering and maintenance of arterial pressure at predetermined values. It allows preprogramming of functions and alarms as well as possible supervision by the doctor. Experiments performed with anesthetized dogs were analyzed to obtain identification and validation of a physiological model. The design, simulation, and testing of an original control algorithm resulted in automatic initial identification of dog parameters, automatic setting of appropriate control parameters, and adequate lowering and posterior maintenance of desired arterial pressure level. A compact, self contained, microprocessor-based controller prototype was constructed and is currently under test.<<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":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121008690","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94504
E. Nevo, Y. Lanir
A dynamic model for the left ventricular mechanics has been developed on the basis of histological characteristics of the wall material in terms of both the muscle fibers and the collagen matrix. The number of free parameters in the model is reduced to five by utilizing established results from various sources relating to the wall microstructure and to the activation properties of the myocardium. It is shown that the remaining free parameters can be reliably estimated from clinically measurable pressure-volume data. This model can thus serve as a useful tool for stress analysis and other studies of cardiac performance such as coronary circulation and metabolic demands.<>
{"title":"Stress analysis and parameter estimation in a structural model of the beating left ventricle","authors":"E. Nevo, Y. Lanir","doi":"10.1109/IEMBS.1988.94504","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94504","url":null,"abstract":"A dynamic model for the left ventricular mechanics has been developed on the basis of histological characteristics of the wall material in terms of both the muscle fibers and the collagen matrix. The number of free parameters in the model is reduced to five by utilizing established results from various sources relating to the wall microstructure and to the activation properties of the myocardium. It is shown that the remaining free parameters can be reliably estimated from clinically measurable pressure-volume data. This model can thus serve as a useful tool for stress analysis and other studies of cardiac performance such as coronary circulation and metabolic demands.<<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":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126517648","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94427
K. Laurita, C.W. Thomas, M. Kavuru, H. Vesselle, J. Liebman
A third-generation multichannel data acquisition system has been designed for cardiac electrogram analysis. The system is capable of recording data from 240 electrode sites, sampling at 2000 Hz. The design required special-purpose front-end electronics for intraoperative recordings, and high-bandwidth data acquisition for analysis of data on line. These design requirements are an attempt to simplify the problems associated with patient safety (leakage current) and the rapid analysis of large amounts of data.<>
{"title":"Data acquisition system for cardiac mapping","authors":"K. Laurita, C.W. Thomas, M. Kavuru, H. Vesselle, J. Liebman","doi":"10.1109/IEMBS.1988.94427","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94427","url":null,"abstract":"A third-generation multichannel data acquisition system has been designed for cardiac electrogram analysis. The system is capable of recording data from 240 electrode sites, sampling at 2000 Hz. The design required special-purpose front-end electronics for intraoperative recordings, and high-bandwidth data acquisition for analysis of data on line. These design requirements are an attempt to simplify the problems associated with patient safety (leakage current) and the rapid analysis of large amounts of data.<<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":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126118855","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 : 1988-09-01DOI: 10.1109/IEMBS.1988.94735
P. J. Loughlin, W. Bowes, D. Westenskow
Using olive oil to simulate body tissues, a mechanical model of uptake and elimination of inhalation anesthetics was developed. Body tissues were grouped according to anesthetic solubility and blood perfusion, and modeled with equivalent oil volumes. Changes in cardiac output were simulated by varying gas flows through the oil chambers. Alveolar ventilation was augmented by adjusting the minute ventilation setting of the ventilator. During 64 minutes of uptake and washout, the mechanical model end-tidal halothane concentration remained within 0.07 vol.% of a computer simulation. The model may prove useful in developing and testing anesthesia equipment without the need for animal experiments or human volunteers.<>
{"title":"A mechanical model to simulate uptake and elimination of inhalation anesthetics","authors":"P. J. Loughlin, W. Bowes, D. Westenskow","doi":"10.1109/IEMBS.1988.94735","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94735","url":null,"abstract":"Using olive oil to simulate body tissues, a mechanical model of uptake and elimination of inhalation anesthetics was developed. Body tissues were grouped according to anesthetic solubility and blood perfusion, and modeled with equivalent oil volumes. Changes in cardiac output were simulated by varying gas flows through the oil chambers. Alveolar ventilation was augmented by adjusting the minute ventilation setting of the ventilator. During 64 minutes of uptake and washout, the mechanical model end-tidal halothane concentration remained within 0.07 vol.% of a computer simulation. The model may prove useful in developing and testing anesthesia equipment without the need for animal experiments or human volunteers.<<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":"1988-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129366454","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 : 1988-04-25DOI: 10.1109/IEMBS.1988.94978
R. Johnson, A. Preece, J. L. Murfin
A novel type of inexpensive electromagnetic hyperthermia applicator is designed which can be described for a wide range of sizes and frequencies. The applicator can be deformed in two planes to follow a desired contour. Deformation of the applicator slightly changes the operating frequency, so that either some means of fine tuning or a tunable power source must be used. For a large aperture an array of such applicators would enable the power distribution, and hence heating, over a wide area to be controlled by adjustment of the power input to individual applicators of the array.<>
{"title":"Flexible electromagnetic hyperthermia applicator","authors":"R. Johnson, A. Preece, J. L. Murfin","doi":"10.1109/IEMBS.1988.94978","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94978","url":null,"abstract":"A novel type of inexpensive electromagnetic hyperthermia applicator is designed which can be described for a wide range of sizes and frequencies. The applicator can be deformed in two planes to follow a desired contour. Deformation of the applicator slightly changes the operating frequency, so that either some means of fine tuning or a tunable power source must be used. For a large aperture an array of such applicators would enable the power distribution, and hence heating, over a wide area to be controlled by adjustment of the power input to individual applicators of the array.<<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":"1988-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125536857","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 : 1986-12-01DOI: 10.1109/IEMBS.1988.94772
S. Hirokawa, K. Matsumura
Sequential gait-steps in children were statistically analyzed in terms of distance and temporal factors using a recently developed walkway system. The gaits were examined and compared with the adults' gaits. The basic state variable statistics were obtained from 109 five-year-old children. The development of the gait patterns according to age was then analyzed for 75 children aged one to six. The changes in the gait patterns with respect to velocity were analyzed for 29 children five and six years of age. The results are presented and discussed.<>
{"title":"Child gait patterns on the basis of temporal and distance factors","authors":"S. Hirokawa, K. Matsumura","doi":"10.1109/IEMBS.1988.94772","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94772","url":null,"abstract":"Sequential gait-steps in children were statistically analyzed in terms of distance and temporal factors using a recently developed walkway system. The gaits were examined and compared with the adults' gaits. The basic state variable statistics were obtained from 109 five-year-old children. The development of the gait patterns according to age was then analyzed for 75 children aged one to six. The changes in the gait patterns with respect to velocity were analyzed for 29 children five and six years of age. The results are presented and discussed.<<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":"1986-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121552679","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.1988.94556
M. Nakamura, T. Nagasawa, Y. Suzuki, S. Kobayashi
The authors extend their previous computer simulation for radionuclide cardiac studies to eight components. The eight components correspond to the superior vena cava, the right atrium, the right ventricle, the pulmonary artery, the lung, the left atrium, the left ventricule, and the aorta. The ability and limitations of the method to recover exact components are discussed.<>
{"title":"Maximum entropy component recovery: a numerical investigation for radionuclide angiography","authors":"M. Nakamura, T. Nagasawa, Y. Suzuki, S. Kobayashi","doi":"10.1109/IEMBS.1988.94556","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94556","url":null,"abstract":"The authors extend their previous computer simulation for radionuclide cardiac studies to eight components. The eight components correspond to the superior vena cava, the right atrium, the right ventricle, the pulmonary artery, the lung, the left atrium, the left ventricule, and the aorta. The ability and limitations of the method to recover exact components are discussed.<<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":"115364416","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.1988.95082
N. Lamarra, B. Whipp, S. Ward
Intra-breath measurements allow study of certain pulmonary variables. The authors show that mean alveolar PCO/sub 2/ (which closely reflects arterial PCO/sub 2/ in normal subjects) and volume series dead space can be measured online, breath-by-breath. Further study of the intra-breath profiles of such variables (e.g. PCO/sub 2/, PO/sub 2/, R, N/sub 2/, Ar/N/sub 2/) are expected to improve understanding of both normal and impaired lung function.<>
{"title":"Physiological inferences from intra-breath measurement of pulmonary gas exchange","authors":"N. Lamarra, B. Whipp, S. Ward","doi":"10.1109/IEMBS.1988.95082","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.95082","url":null,"abstract":"Intra-breath measurements allow study of certain pulmonary variables. The authors show that mean alveolar PCO/sub 2/ (which closely reflects arterial PCO/sub 2/ in normal subjects) and volume series dead space can be measured online, breath-by-breath. Further study of the intra-breath profiles of such variables (e.g. PCO/sub 2/, PO/sub 2/, R, N/sub 2/, Ar/N/sub 2/) are expected to improve understanding of both normal and impaired lung function.<<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":"115508079","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.1988.94999
H. Sekii, H. Takano, Y. Taenaka, S. Takatani, H. Noda, M. Kinoshita, E. Noda, A. Yagura, T. Akutsu
In order to estimate left-ventricular output from the pulse-pressure and pressure-flow relationship during left-ventricular-assist-device (LVAD) pumping, three methods were compared. The first method is based on the aortic compliance, while the second and third methods are based on the peripheral vascular resistance and the aortic impedance, respectively. Prior to clinical application, these methods were evaluated in a mock circulatory loop. The in vitro study revealed that in comparison to the electromagnetic flowmetering the second and third methods yielded higher correlation coefficients than the first method, indicating that they are more suitable for practical application during LVAD pumping.<>
{"title":"Beat-to-beat prediction of left ventricular output during left ventricular bypass pumping","authors":"H. Sekii, H. Takano, Y. Taenaka, S. Takatani, H. Noda, M. Kinoshita, E. Noda, A. Yagura, T. Akutsu","doi":"10.1109/IEMBS.1988.94999","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94999","url":null,"abstract":"In order to estimate left-ventricular output from the pulse-pressure and pressure-flow relationship during left-ventricular-assist-device (LVAD) pumping, three methods were compared. The first method is based on the aortic compliance, while the second and third methods are based on the peripheral vascular resistance and the aortic impedance, respectively. Prior to clinical application, these methods were evaluated in a mock circulatory loop. The in vitro study revealed that in comparison to the electromagnetic flowmetering the second and third methods yielded higher correlation coefficients than the first method, indicating that they are more suitable for practical application during LVAD pumping.<<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":"117046845","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.1988.95260
C. Reuter, J. Battocletti, J. Myklebust, D. Maiman
The use of very strong pulsed magnetic fields to stimulate excitable tissue has been investigated. The advantage of this method as opposed to the conventional method, electrical stimulation, is that it is noninvasive and virtually painless. However, the drawbacks are that the site of stimulation is less well defined than for electrical stimulation and repetition rates for stimuli are often limited to 1 or 2 per second. In this study, various stimulation parameters for magnetic stimulation of the peripheral nerves in the arms were investigated. Systems were developed that would yield stimulation. The median nerve in the upper arm was stimulated and the results were plotted in a method similar to the strength-duration curve.<>
{"title":"Magnetic stimulation of peripheral nerves","authors":"C. Reuter, J. Battocletti, J. Myklebust, D. Maiman","doi":"10.1109/IEMBS.1988.95260","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.95260","url":null,"abstract":"The use of very strong pulsed magnetic fields to stimulate excitable tissue has been investigated. The advantage of this method as opposed to the conventional method, electrical stimulation, is that it is noninvasive and virtually painless. However, the drawbacks are that the site of stimulation is less well defined than for electrical stimulation and repetition rates for stimuli are often limited to 1 or 2 per second. In this study, various stimulation parameters for magnetic stimulation of the peripheral nerves in the arms were investigated. Systems were developed that would yield stimulation. The median nerve in the upper arm was stimulated and the results were plotted in a method similar to the strength-duration curve.<<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":"117153880","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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