Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.415441
J. Scharf, T. L. Rusch
Spectral analysis of physiologic waveforms provides a window into the autonomic nervous system. Although electrocardiograms (EKG) and arterial blood pressure waveforms (ABP) have been analyzed extensively in this manner, the authors' objective was to determine if similar information could be extracted from digital pulse plethysmograms (DPP). DPP spectral analysis during application of known autonomic stimuli (hypoxemia, phenyleprine, general anesthesia) resulted in the anticipated changes in autonomic spectra. DPP may provide autonomic information regarding the peripheral circulation which is not available in EKG, and less invasive than ABP.
{"title":"Spectral analysis of digital pulse plethysmograms during autonomic nervous system changes","authors":"J. Scharf, T. L. Rusch","doi":"10.1109/IEMBS.1994.415441","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415441","url":null,"abstract":"Spectral analysis of physiologic waveforms provides a window into the autonomic nervous system. Although electrocardiograms (EKG) and arterial blood pressure waveforms (ABP) have been analyzed extensively in this manner, the authors' objective was to determine if similar information could be extracted from digital pulse plethysmograms (DPP). DPP spectral analysis during application of known autonomic stimuli (hypoxemia, phenyleprine, general anesthesia) resulted in the anticipated changes in autonomic spectra. DPP may provide autonomic information regarding the peripheral circulation which is not available in EKG, and less invasive than ABP.","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"124 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":"128171633","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.1994.412063
M. Daley, H. Pasupathy, J. Robertson, C. Leffler
The overall objective of this research is to develop tools which may improve the care of accident victims with severe closed head-injury. With the use of a laboratory model, arterial and intracranial pressure signals were obtained under conditions of intact regulation of cerebral blood flow and massive dilation. During elevated intracranial pressure and intact regulation, positive pressure inhalation appears to briefly occlude venous flow into the cranial sinuses during inspiration. As a result, the intracranial pressure and arterial pressure signals are not similar. In contrast, when maximal dilation causes failure of regulation of cerebral blood flow, the intracranial pressure signal is approximately proportional to the arterial pressure signal. Comparison of the cross-correlation function derived from the intracranial and arterial pressure signals to the autocorrelation function of the arterial signal reveals that the two correlation functions are: 1) different during intact autoregulation; and 2) nearly identical during dilation induced failure of regulation of cerebral blood flow.<>
{"title":"Detection of maximal cerebral vasodilation by correlation of arterial and intracranial pressure signals","authors":"M. Daley, H. Pasupathy, J. Robertson, C. Leffler","doi":"10.1109/IEMBS.1994.412063","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412063","url":null,"abstract":"The overall objective of this research is to develop tools which may improve the care of accident victims with severe closed head-injury. With the use of a laboratory model, arterial and intracranial pressure signals were obtained under conditions of intact regulation of cerebral blood flow and massive dilation. During elevated intracranial pressure and intact regulation, positive pressure inhalation appears to briefly occlude venous flow into the cranial sinuses during inspiration. As a result, the intracranial pressure and arterial pressure signals are not similar. In contrast, when maximal dilation causes failure of regulation of cerebral blood flow, the intracranial pressure signal is approximately proportional to the arterial pressure signal. Comparison of the cross-correlation function derived from the intracranial and arterial pressure signals to the autocorrelation function of the arterial signal reveals that the two correlation functions are: 1) different during intact autoregulation; and 2) nearly identical during dilation induced failure of regulation of cerebral blood flow.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"113 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":"128160533","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.1994.412172
D.F. Mayfield, F. Claydon
The objectives of this study were to examine the effects of geometric uncertainty when computing intracavitary probe potentials and endocardial potentials via a forward and inverse solution, respectively. A cylindrical probe with 57 unipolar electrodes and 56 subendocardial electrodes were used to simultaneously record potentials within the left ventricular (LV) cavity and LV endocardium, respectively. Geometric uncertainty was examined by: (1) rotating the intracavitary probe surface from its known position within the LV cavity about its long (z) axis by -20/spl deg/ and +20/spl deg/; and (2) randomly perturbing the known LV endocardial geometry by /spl plusmn/5 mm. Quantitative comparison of results showed that the levels of geometric uncertainty used in this study did not have significant effects on the accuracy of the volume conductor model. Given the imaging modalities currently available, these levels of geometric uncertainty should be attainable when conducting studies of this nature.<>
{"title":"Examining the effects of geometric uncertainty when computing endocardial and intracavitary probe potentials using a surface integral equation solution","authors":"D.F. Mayfield, F. Claydon","doi":"10.1109/IEMBS.1994.412172","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412172","url":null,"abstract":"The objectives of this study were to examine the effects of geometric uncertainty when computing intracavitary probe potentials and endocardial potentials via a forward and inverse solution, respectively. A cylindrical probe with 57 unipolar electrodes and 56 subendocardial electrodes were used to simultaneously record potentials within the left ventricular (LV) cavity and LV endocardium, respectively. Geometric uncertainty was examined by: (1) rotating the intracavitary probe surface from its known position within the LV cavity about its long (z) axis by -20/spl deg/ and +20/spl deg/; and (2) randomly perturbing the known LV endocardial geometry by /spl plusmn/5 mm. Quantitative comparison of results showed that the levels of geometric uncertainty used in this study did not have significant effects on the accuracy of the volume conductor model. Given the imaging modalities currently available, these levels of geometric uncertainty should be attainable when conducting studies of this nature.<<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":"128250227","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.1994.415213
J. Jezewski, J. Wrobel, K. Horoba, I. Zych
Presents results of comparison of two systems for computerized cardiotocography: the KOMPOR system and the Sonicaid System 8000. Two groups of traces: direct traces from the memory of fetal monitor and indirectly obtained traces (transferred from the System 8000 archive) were studied. Final quasi-direct results originate from converting results of indirect records. The method conversion factors were applied to reduce the influence of different averaging used in both the systems. The study indicates that findings concerning computerized cardiotocography can be compared among various medical centres using these systems.<>
{"title":"Comparison of two computer-aided cardiotocography systems: the influence of indirectly obtained input trades","authors":"J. Jezewski, J. Wrobel, K. Horoba, I. Zych","doi":"10.1109/IEMBS.1994.415213","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415213","url":null,"abstract":"Presents results of comparison of two systems for computerized cardiotocography: the KOMPOR system and the Sonicaid System 8000. Two groups of traces: direct traces from the memory of fetal monitor and indirectly obtained traces (transferred from the System 8000 archive) were studied. Final quasi-direct results originate from converting results of indirect records. The method conversion factors were applied to reduce the influence of different averaging used in both the systems. The study indicates that findings concerning computerized cardiotocography can be compared among various medical centres using these systems.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"61 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":"128671405","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.1994.412181
M. Loew, Dunling Li
To compress medical images in a lossy way that preserves their diagnostic value, the authors have combined lossless compression techniques with a fractal image compression method using two kinds of iterated function systems: partitioned, and condensation-model. The algorithm appears to yield a compression ratio of about 15:1 without perceptible degradation.<>
{"title":"Medical image compression using a fractal model with condensation","authors":"M. Loew, Dunling Li","doi":"10.1109/IEMBS.1994.412181","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412181","url":null,"abstract":"To compress medical images in a lossy way that preserves their diagnostic value, the authors have combined lossless compression techniques with a fractal image compression method using two kinds of iterated function systems: partitioned, and condensation-model. The algorithm appears to yield a compression ratio of about 15:1 without perceptible degradation.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"6 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":"127156056","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.1994.412057
C. Capelle, C. Faik, C. Trullemans, C. Veraart
Deals with the design of an experimental sensory substitution prosthesis for rehabilitation of blindness. A conceptual model of sensory substitution is proposed, and the general principles of the prosthesis are described. Psychophysical experimentations based on this conceptual model showed performance increasing during learning.<>
{"title":"Real time experimental visual prosthesis using sensory substitution of vision by audition","authors":"C. Capelle, C. Faik, C. Trullemans, C. Veraart","doi":"10.1109/IEMBS.1994.412057","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412057","url":null,"abstract":"Deals with the design of an experimental sensory substitution prosthesis for rehabilitation of blindness. A conceptual model of sensory substitution is proposed, and the general principles of the prosthesis are described. Psychophysical experimentations based on this conceptual model showed performance increasing during learning.<<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":"131061605","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.1994.415188
E. McAdams, A. Lackermeier, J. Jossinet
An equivalent circuit model of the electrode-gel-skin interface impedance is described. It is shown that the circuit parameters have physical significance and that the study of their variations with time and electrodermal activity furnishes considerable insight into underlying physical processes. As hydrogels are hydrophillic, they adsorb excess moisture from the skin surface. Hydrogel based electrodes therefore have the ability to recover following bursts of electrodermal activity and are thus, it is suggested, well suited for use in psychophysiological studies.<>
{"title":"AC impedance of the hydrogel-skin interface","authors":"E. McAdams, A. Lackermeier, J. Jossinet","doi":"10.1109/IEMBS.1994.415188","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415188","url":null,"abstract":"An equivalent circuit model of the electrode-gel-skin interface impedance is described. It is shown that the circuit parameters have physical significance and that the study of their variations with time and electrodermal activity furnishes considerable insight into underlying physical processes. As hydrogels are hydrophillic, they adsorb excess moisture from the skin surface. Hydrogel based electrodes therefore have the ability to recover following bursts of electrodermal activity and are thus, it is suggested, well suited for use in psychophysiological studies.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"6 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":"126948904","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.1994.415466
T. Lamotte, A. Priez, E. Lepoivre, J. Duchêne, C. Tarrière
Evolution of the amplitude probability density function (APDF) of EMG signals from neck muscles were studied in order to make an objective diagnostic of the benefit of using a head rest in a car. This method is simple: several APDFs over a long period of time are computed and observed. Interesting results are obtained with 6 subjects (N=8), especially with evolutions of static and median load. The sign of the evolution appears to be discriminant. Obviously, the major drawback is the lack of explanation of results observed: as the classical APDF, this method is only an a posteriori approach.
{"title":"Time varying amplitude probability density function: application to the study of head rest comfort in a car","authors":"T. Lamotte, A. Priez, E. Lepoivre, J. Duchêne, C. Tarrière","doi":"10.1109/IEMBS.1994.415466","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415466","url":null,"abstract":"Evolution of the amplitude probability density function (APDF) of EMG signals from neck muscles were studied in order to make an objective diagnostic of the benefit of using a head rest in a car. This method is simple: several APDFs over a long period of time are computed and observed. Interesting results are obtained with 6 subjects (N=8), especially with evolutions of static and median load. The sign of the evolution appears to be discriminant. Obviously, the major drawback is the lack of explanation of results observed: as the classical APDF, this method is only an a posteriori approach.","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"47 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":"130552958","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.1994.412109
M. Schaldach, A. Urbaszek, H. Hutten
A numerical model of the human cardiovascular system was developed to study the chronotropic and inotropic responses of the heart as well as peripheral adaptation to changing metabolic demands. Autonomic nervous system (ANS) control covers all three levels of the model: circulation, heart mechanics and myocardial cell. The purpose of the simulations is to investigate the control aspects of rate responsive pacing and to develop and test algorithms for rate adaptation based on cardiac control signals, of which unipolar intracardiac impedance measurements are of special interest.<>
{"title":"Simulation of closed-loop rate-adaptive pacing with a numerical heart and circulation model","authors":"M. Schaldach, A. Urbaszek, H. Hutten","doi":"10.1109/IEMBS.1994.412109","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412109","url":null,"abstract":"A numerical model of the human cardiovascular system was developed to study the chronotropic and inotropic responses of the heart as well as peripheral adaptation to changing metabolic demands. Autonomic nervous system (ANS) control covers all three levels of the model: circulation, heart mechanics and myocardial cell. The purpose of the simulations is to investigate the control aspects of rate responsive pacing and to develop and test algorithms for rate adaptation based on cardiac control signals, of which unipolar intracardiac impedance measurements are of special interest.<<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":"132855236","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.1994.415399
S. Schiff
Wavelet transforms are used in conjunction with surrogate data techniques for epileptic spike detection and seizure localization from electroencephalogram data. Fast wavelet transform techniques demonstrate vast improvement in computational efficiency without a significant decrement in the quality of feature extraction.
{"title":"Wavelet transforms for epileptic spike and seizure detection","authors":"S. Schiff","doi":"10.1109/IEMBS.1994.415399","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415399","url":null,"abstract":"Wavelet transforms are used in conjunction with surrogate data techniques for epileptic spike detection and seizure localization from electroencephalogram data. Fast wavelet transform techniques demonstrate vast improvement in computational efficiency without a significant decrement in the quality of feature extraction.","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"63 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":"132892804","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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