Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5761956
H. Gomi, Y. Koike, M. Kawato
We compared dynamic hand stiffness during discrete multi-joint arm movement and static stiffness during posture control in order to investigate computational strategy for arm control by the central nervous system. Estimated stiffness during movement obtained by applying small perturbations were lower than those during static posture near the end of the movement. This result supports our simulation study that the virtual equilibrium trajectory of the hand is complicated in its shape to compensate nonlinear interaction forces of the multi-joint arm especially for fast movements.
{"title":"Human hand stiffness during discrete point-to-point multi-joint movement","authors":"H. Gomi, Y. Koike, M. Kawato","doi":"10.1109/IEMBS.1992.5761956","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761956","url":null,"abstract":"We compared dynamic hand stiffness during discrete multi-joint arm movement and static stiffness during posture control in order to investigate computational strategy for arm control by the central nervous system. Estimated stiffness during movement obtained by applying small perturbations were lower than those during static posture near the end of the movement. This result supports our simulation study that the virtual equilibrium trajectory of the hand is complicated in its shape to compensate nonlinear interaction forces of the multi-joint arm especially for fast movements.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"86 1","pages":"1628-1629"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73474107","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5761738
W. Pickard
Seemingly trivial exogenous ELF fields can have readily detectable biological effects if there is sufficient concentration of the fields upon appropriate structures, if each structure so affected modulates an associated sensitive process, and if the outputs of an ensemble of such processes are subsequently integrated; this mechanism is illustrated by the well-known sensitivity of sharks and rays to applied electric fields. Moreover, if an exogenous influence affects a physiological variable at all and if the probability distribution of that variable is related to the incidence of an observable sequela, then the incidence of that sequela can be doubled by an arbitrarily small change of the influence if the observable sequela was sufficiently rare to begin with! Finally, it is asserted that neither a specialized sensory system in an aquatic organism nor a speculative mechanism by which the incidence of rare events might be increased is sufficient to demonstrate convincingly the existence of ELF bioeffects of relevance to humans: only positive experimental data, quantitatively replicable upon demand, suffice to do that; and the generation of such data should be the primary goal of ELF bioeffects research.
{"title":"Prospects for finding unexpectedly low thresholds for the biological effects of exogenous ELF fields","authors":"W. Pickard","doi":"10.1109/IEMBS.1992.5761738","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761738","url":null,"abstract":"Seemingly trivial exogenous ELF fields can have readily detectable biological effects if there is sufficient concentration of the fields upon appropriate structures, if each structure so affected modulates an associated sensitive process, and if the outputs of an ensemble of such processes are subsequently integrated; this mechanism is illustrated by the well-known sensitivity of sharks and rays to applied electric fields. Moreover, if an exogenous influence affects a physiological variable at all and if the probability distribution of that variable is related to the incidence of an observable sequela, then the incidence of that sequela can be doubled by an arbitrarily small change of the influence if the observable sequela was sufficiently rare to begin with! Finally, it is asserted that neither a specialized sensory system in an aquatic organism nor a speculative mechanism by which the incidence of rare events might be increased is sufficient to demonstrate convincingly the existence of ELF bioeffects of relevance to humans: only positive experimental data, quantitatively replicable upon demand, suffice to do that; and the generation of such data should be the primary goal of ELF bioeffects research.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"249 1","pages":"2877-2878"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73528649","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5761096
R. Lehtinen, H. Sievanen, J. Malmivuo
The exercise ECG test is the most widely used method of evaluating myocardial ischemia, but its diagnostic accuracy is only about 70 %. Many studies introducing different diagnostic computerized exercise ECG parameters have been published, but according to the authors' knowledge there is no overall comparison of these parameters. We calculated 52 exercise ECG parameters from the ST-segment value, ST-segment shape and ST-segment/heart rate slope and compared the diagnostic power of these parameters by ROC-analysis. We found that ST-segment/heart rate slope has better diagnostic power than ST-segment depression or ST-segment shape alone. Another result was that the ST-segment shape seemed to be better diagnostic parameter than ST-segment depression when measuring an individual lead. However, further research with larger patient material is needed to get statistically significant differences between the parameters.
{"title":"Comparison of computerized exercise ECG parameters in detecting myocardial ischemia","authors":"R. Lehtinen, H. Sievanen, J. Malmivuo","doi":"10.1109/IEMBS.1992.5761096","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761096","url":null,"abstract":"The exercise ECG test is the most widely used method of evaluating myocardial ischemia, but its diagnostic accuracy is only about 70 %. Many studies introducing different diagnostic computerized exercise ECG parameters have been published, but according to the authors' knowledge there is no overall comparison of these parameters. We calculated 52 exercise ECG parameters from the ST-segment value, ST-segment shape and ST-segment/heart rate slope and compared the diagnostic power of these parameters by ROC-analysis. We found that ST-segment/heart rate slope has better diagnostic power than ST-segment depression or ST-segment shape alone. Another result was that the ST-segment shape seemed to be better diagnostic parameter than ST-segment depression when measuring an individual lead. However, further research with larger patient material is needed to get statistically significant differences between the parameters.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"17 1","pages":"535-536"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73631413","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5761086
D. Jugo, Medina Ruben, Carrasco Hugo
Âbstraet-Vàz present paper deals with the analysis of the High Resolution Surface Electrocardiogram in patients with Chagas disease. The spectral estimation technique is based on the Discrete Fourier Transfom (DFT). evaluated over a 300 milliseconds segment situated around the QRS wave in the averaged signal, corresponding to three orthogonal derivations X, Y and Z. The results are presented as a spectro-temporal mapping of the signal and a comparison between normal subjects and patients with Chagas' disease based on the area between 0 and 300 Hz for a 76 milliseconds frame including the end of the QRS.
{"title":"Spectral analysis of the surface electrocardiogram in patients with Chagas disease","authors":"D. Jugo, Medina Ruben, Carrasco Hugo","doi":"10.1109/IEMBS.1992.5761086","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761086","url":null,"abstract":"Âbstraet-Vàz present paper deals with the analysis of the High Resolution Surface Electrocardiogram in patients with Chagas disease. The spectral estimation technique is based on the Discrete Fourier Transfom (DFT). evaluated over a 300 milliseconds segment situated around the QRS wave in the averaged signal, corresponding to three orthogonal derivations X, Y and Z. The results are presented as a spectro-temporal mapping of the signal and a comparison between normal subjects and patients with Chagas' disease based on the area between 0 and 300 Hz for a 76 milliseconds frame including the end of the QRS.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"51 1","pages":"514-515"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73636931","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5761047
D. Feng
An explicit model for tracer plasma time-activity curve (PTAC) is proposed based on practical experimental data in this paper, which can be potentially used to measure PTAC noninvasively from external probe or left ventricle images and to study the reliability of other physiological parameters measurements with positron emission tomography, which require PTAC as the input information.
{"title":"An explicit model for noninvasive measurement of blood samples","authors":"D. Feng","doi":"10.1109/IEMBS.1992.5761047","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761047","url":null,"abstract":"An explicit model for tracer plasma time-activity curve (PTAC) is proposed based on practical experimental data in this paper, which can be potentially used to measure PTAC noninvasively from external probe or left ventricle images and to study the reliability of other physiological parameters measurements with positron emission tomography, which require PTAC as the input information.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"2015 1","pages":"434-435"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73906893","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5762019
K. Visser, M. Gels, J. Muntinga, W. Terpstra, J. Schut
The fluid shifts of an upper arm tissue segment under an occluding cuff were estimated from electrical impedance measurements. This was done using parameter estimation with a model. The model included parameters describing the arterial and venous pressure-volume relationship. To gain insight into the precision of the method, repeated measurements were made on healthy volunteers. Most parameters showed a large variation (13–44 %). This variation could only partly be explained by variations in the measured quantities.
{"title":"Properties of the upper arm vascular bed investigated by electrical impedance measurements in healthy subjects","authors":"K. Visser, M. Gels, J. Muntinga, W. Terpstra, J. Schut","doi":"10.1109/IEMBS.1992.5762019","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5762019","url":null,"abstract":"The fluid shifts of an upper arm tissue segment under an occluding cuff were estimated from electrical impedance measurements. This was done using parameter estimation with a model. The model included parameters describing the arterial and venous pressure-volume relationship. To gain insight into the precision of the method, repeated measurements were made on healthy volunteers. Most parameters showed a large variation (13–44 %). This variation could only partly be explained by variations in the measured quantities.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"27 1","pages":"1742-1743"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73927579","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5762163
D. Saint-Félix, C. Picard, C. Ponchut, R. Romeas, A. Rougée, Y. Trousset, R. Carnpagnolo, P. Le Masson, P. Schermesser, S. Crocci, Y. Gandon, Y. Rolland, J. Scarabin, M. Amiel, G. Finet, T. Moll
A new system has been designed and built to validate the concept of 3D computerized Χ-ray angiography. It addresses all the difficulties met from the acquisition of raw data on a patient to the display of the reconstructed volume. The first in vivo results obtained with this system are presented.
{"title":"A new system for 3D computerized X-ray angiography: First in vivo results","authors":"D. Saint-Félix, C. Picard, C. Ponchut, R. Romeas, A. Rougée, Y. Trousset, R. Carnpagnolo, P. Le Masson, P. Schermesser, S. Crocci, Y. Gandon, Y. Rolland, J. Scarabin, M. Amiel, G. Finet, T. Moll","doi":"10.1109/IEMBS.1992.5762163","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5762163","url":null,"abstract":"A new system has been designed and built to validate the concept of 3D computerized Χ-ray angiography. It addresses all the difficulties met from the acquisition of raw data on a patient to the display of the reconstructed volume. The first in vivo results obtained with this system are presented.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"41 1","pages":"2051-2052"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74088613","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5761284
R. Summers, E. Carson, S. Andreassen
A physiologically-based model of the relevant cardiovascular, respiratory and associated processes of a patient resident in a high dependency environment is described. The model will be implemented using a Causal Probabilistic Network, and will be tuned to represent the individual patient. It will provide advice, for instance regarding changes in ventilator therapy, and the model will also be used to detect and correct equipment malfunction and operator error.
{"title":"Causal probabilistic modelling for clinical decision support in the high dependency environment","authors":"R. Summers, E. Carson, S. Andreassen","doi":"10.1109/IEMBS.1992.5761284","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761284","url":null,"abstract":"A physiologically-based model of the relevant cardiovascular, respiratory and associated processes of a patient resident in a high dependency environment is described. The model will be implemented using a Causal Probabilistic Network, and will be tuned to represent the individual patient. It will provide advice, for instance regarding changes in ventilator therapy, and the model will also be used to detect and correct equipment malfunction and operator error.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"68 1","pages":"869-870"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75636237","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5762170
R. Kikinis, H. Cline, D. Altobelli, M. Halle, W. Lorensen, B. Rhodes, F. Jólesz
A system for computer-assisted planning of surgical procedures has been developped. Its components are a workstation with hardware accelerated 3D rendering board, a software environment and a set of procedures. Data sets from over 41 patients have been analyzed so far. We found a potential for improving the surgeons understanding of the anatomical situation he was going to face and for reducing the time spent during surgery to understand the altered anatomy.
{"title":"Computer assisted planning of surgical procedures","authors":"R. Kikinis, H. Cline, D. Altobelli, M. Halle, W. Lorensen, B. Rhodes, F. Jólesz","doi":"10.1109/IEMBS.1992.5762170","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5762170","url":null,"abstract":"A system for computer-assisted planning of surgical procedures has been developped. Its components are a workstation with hardware accelerated 3D rendering board, a software environment and a set of procedures. Data sets from over 41 patients have been analyzed so far. We found a potential for improving the surgeons understanding of the anatomical situation he was going to face and for reducing the time spent during surgery to understand the altered anatomy.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"1 1","pages":"2065-2066"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75666374","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 : 1992-10-01DOI: 10.1109/IEMBS.1992.5762055
C. Riddell, M. Bourguignon, B. Bendriem, V. Frouin, A. Syrota
When SPECT sinograms are truncated, the Iterative Reprojection Reconstruction (IRR) algorithm based on the Radon transform cannot restore the distribution that would be obtained with the complete projection data set, even in the field of view taken as a region of interest. Nevertheless, when the attenuation characteristics are known and an attenuation correction is incorporated in the IRR scheme, the source distribution can be recovered in the field of view and, in the particular case of a contrasted attenuation map, even outside the region.
{"title":"Iterative Reprojection Reconstruction algorithm with attenuation correction applied to truncated projections in SPECT","authors":"C. Riddell, M. Bourguignon, B. Bendriem, V. Frouin, A. Syrota","doi":"10.1109/IEMBS.1992.5762055","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5762055","url":null,"abstract":"When SPECT sinograms are truncated, the Iterative Reprojection Reconstruction (IRR) algorithm based on the Radon transform cannot restore the distribution that would be obtained with the complete projection data set, even in the field of view taken as a region of interest. Nevertheless, when the attenuation characteristics are known and an attenuation correction is incorporated in the IRR scheme, the source distribution can be recovered in the field of view and, in the particular case of a contrasted attenuation map, even outside the region.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"117 1","pages":"1818-1820"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75752339","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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