Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.415187
S. Kun, R. Peura
The objective of the authors' research is to develop an innovative technique for monitoring and measurement of tissue perfusion/ischemia levels. Assessment of tissue perfusion/ischemia is of critical importance in plastic and reconstructive surgery, for postoperative monitoring of transplanted muscle flaps. In order to design an instrument that would approximate as closely as possible the requirements of the "ideal" perfusion/ischemia monitor, the authors initiated research to investigate the correlation between tissue impedance measurements at various frequencies, and the tissue pH, a proven indicator of perfusion/ischemia level of the tissue. The authors' preliminary experiments were performed in vivo on rabbit anterior tibialis muscle with an impedance spectroscopic system that measures the real component of tissue impedance at seven frequencies in the range of 1 kHz to 100 kHz. The obtained results indicate that there is a strong correlation between the tissue resistivities measured, and the independent indicator of tissue ischemia.<>
{"title":"Tissue ischemia detection using impedance spectroscopy","authors":"S. Kun, R. Peura","doi":"10.1109/IEMBS.1994.415187","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415187","url":null,"abstract":"The objective of the authors' research is to develop an innovative technique for monitoring and measurement of tissue perfusion/ischemia levels. Assessment of tissue perfusion/ischemia is of critical importance in plastic and reconstructive surgery, for postoperative monitoring of transplanted muscle flaps. In order to design an instrument that would approximate as closely as possible the requirements of the \"ideal\" perfusion/ischemia monitor, the authors initiated research to investigate the correlation between tissue impedance measurements at various frequencies, and the tissue pH, a proven indicator of perfusion/ischemia level of the tissue. The authors' preliminary experiments were performed in vivo on rabbit anterior tibialis muscle with an impedance spectroscopic system that measures the real component of tissue impedance at seven frequencies in the range of 1 kHz to 100 kHz. The obtained results indicate that there is a strong correlation between the tissue resistivities measured, and the independent indicator of tissue ischemia.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"43 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":"131462626","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.1994.412075
A. M. Bianchi, U. Scholz, Luca T. Mainardi, P. Orlandini, G. Pozza, Sergio Cerutti
The respiratory sinus arrhythmia that influences the heart rate variability (HRV) signal is well quantifiable, by means of frequency analysis, in stationary conditions, when the respiration rate is uniform. In many physiological and pathological conditions, however, the respiration is characterized by transitions and variations which compromise the hypothesis of stationarity required for a correct spectral analysis. Here, an adaptive filter implemented in lattice form is employed for predicting the influence of respiration on the HRV and for separating this contribution from the other ones, namely from the low frequency (LF) oscillations also present in the HRV. The filter was employed for studying the sympatho-vagal balance in normal subjects during sleep, and in particular during transitions between different sleep stages.<>
{"title":"Extraction of the respiration influence from the heart rate variability signal by means of lattice adaptive filter","authors":"A. M. Bianchi, U. Scholz, Luca T. Mainardi, P. Orlandini, G. Pozza, Sergio Cerutti","doi":"10.1109/IEMBS.1994.412075","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412075","url":null,"abstract":"The respiratory sinus arrhythmia that influences the heart rate variability (HRV) signal is well quantifiable, by means of frequency analysis, in stationary conditions, when the respiration rate is uniform. In many physiological and pathological conditions, however, the respiration is characterized by transitions and variations which compromise the hypothesis of stationarity required for a correct spectral analysis. Here, an adaptive filter implemented in lattice form is employed for predicting the influence of respiration on the HRV and for separating this contribution from the other ones, namely from the low frequency (LF) oscillations also present in the HRV. The filter was employed for studying the sympatho-vagal balance in normal subjects during sleep, and in particular during transitions between different sleep stages.<<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":"127807093","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.1994.415286
X.-B. Wang, Y. Huang, P. Gascoyne, F.F. Becker
The authors derive an expression for the dielectrophoretic force and rotational torque acting on two neighbouring particles resulting from dipole-dipole interactions induced by an applied AC electric field. Non-uniformities in both the magnitude and phase components of the induced dipolar fields are found to play an important role in pearl-chain formation. Torque on the two particles is proportional to the product of the out-of-phase components of their dipole-moments. Comparison is made between the rotation of particles induced by non-rotating and rotating applied fields.<>
{"title":"Particle dipole-dipole interaction in AC electric fields [cellular application]","authors":"X.-B. Wang, Y. Huang, P. Gascoyne, F.F. Becker","doi":"10.1109/IEMBS.1994.415286","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415286","url":null,"abstract":"The authors derive an expression for the dielectrophoretic force and rotational torque acting on two neighbouring particles resulting from dipole-dipole interactions induced by an applied AC electric field. Non-uniformities in both the magnitude and phase components of the induced dipolar fields are found to play an important role in pearl-chain formation. Torque on the two particles is proportional to the product of the out-of-phase components of their dipole-moments. Comparison is made between the rotation of particles induced by non-rotating and rotating applied fields.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"49 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":"127861692","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.1994.415497
B. Ezenwa, G. Souri, H. Bismar
Describes a voice controlled computer system to enable a multiple sclerosis quadriplegic patient to independently display sheets of paper of various sizes. The system is made up of two subsystems. The first is the voice input module comprising a microphone, a voice card, a voice recognition and control software and relay drivers. The second is the paper display drive mechanism consisting of opto-control mechanism, mechanical rollers, electric motor and the paper tray for holding and retaining papers of different sizes. To use the system, the user trains the recognition software for the key words desired for the tasks. Pilot tests show that the voice control software can be used to activate/deactivate all DC or AC devices connected to the computer relays with high accuracy. The paper turn drive mechanism was also successful in displaying sheets of paper from 3/spl times/5 to 8.5/spl times/11 inches.
{"title":"Voice input for displaying sheets of paper of different sizes","authors":"B. Ezenwa, G. Souri, H. Bismar","doi":"10.1109/IEMBS.1994.415497","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415497","url":null,"abstract":"Describes a voice controlled computer system to enable a multiple sclerosis quadriplegic patient to independently display sheets of paper of various sizes. The system is made up of two subsystems. The first is the voice input module comprising a microphone, a voice card, a voice recognition and control software and relay drivers. The second is the paper display drive mechanism consisting of opto-control mechanism, mechanical rollers, electric motor and the paper tray for holding and retaining papers of different sizes. To use the system, the user trains the recognition software for the key words desired for the tasks. Pilot tests show that the voice control software can be used to activate/deactivate all DC or AC devices connected to the computer relays with high accuracy. The paper turn drive mechanism was also successful in displaying sheets of paper from 3/spl times/5 to 8.5/spl times/11 inches.","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"60 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131672140","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.1994.411942
Farhad Aghili, A. Meghdari
Describes the mechanical design characteristics of an artificial arm. Design objectives to meet are: (a) maximum simplicity and practicality in design; (b) minimum total weight; (c) adequate shape and dimensions; (d) minimum energy consumption from a light external energy resource; (e) adequate dynamic capability compatible with other prosthetic arms. To obtain optimal design parameters for such a system, a software program was written to simulate the behavior of the arm so that design variables could be tested. These parameters strongly influence the choice of mechanisms and components used in the authors' design.<>
{"title":"Mechanical design of a modular arm prosthesis","authors":"Farhad Aghili, A. Meghdari","doi":"10.1109/IEMBS.1994.411942","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411942","url":null,"abstract":"Describes the mechanical design characteristics of an artificial arm. Design objectives to meet are: (a) maximum simplicity and practicality in design; (b) minimum total weight; (c) adequate shape and dimensions; (d) minimum energy consumption from a light external energy resource; (e) adequate dynamic capability compatible with other prosthetic arms. To obtain optimal design parameters for such a system, a software program was written to simulate the behavior of the arm so that design variables could be tested. These parameters strongly influence the choice of mechanisms and components used in the authors' design.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"87 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":"133822141","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.1994.411792
K. Ono, Bin He, J. Z. Yin, R. Cohen
The goal of this study was to evaluate the spatial resolution of body surface Laplacian maps (BSLMs) to localize ventricular electrical activity on the anterior wall of the heart by means of computer simulation. A 3-D computer heart-torso model was used to simulate cardiac electrical activity, BSLMs and body surface potential maps (BSPMs). A two site pacing protocol was used to generate two simultaneous myocardial events on the anterior epicardial wall, and on the anterior endocardial wall. The BSLM showed better performance as compared with the BSPM for localizing initial ventricular activation following two site pacing. The present study suggests that body surface Laplacian mapping merits further investigation to explore its application to the clinical diagnosis of cardiac abnormalities.<>
{"title":"A 3-D computer simulation study of body surface Laplacian maps during ventricular activation","authors":"K. Ono, Bin He, J. Z. Yin, R. Cohen","doi":"10.1109/IEMBS.1994.411792","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411792","url":null,"abstract":"The goal of this study was to evaluate the spatial resolution of body surface Laplacian maps (BSLMs) to localize ventricular electrical activity on the anterior wall of the heart by means of computer simulation. A 3-D computer heart-torso model was used to simulate cardiac electrical activity, BSLMs and body surface potential maps (BSPMs). A two site pacing protocol was used to generate two simultaneous myocardial events on the anterior epicardial wall, and on the anterior endocardial wall. The BSLM showed better performance as compared with the BSPM for localizing initial ventricular activation following two site pacing. The present study suggests that body surface Laplacian mapping merits further investigation to explore its application to the clinical diagnosis of cardiac abnormalities.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"11 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":"115504051","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.1994.412024
P. Ragan, S. Eisenberg, W. Wang
A three-dimensional finite element model representing the conductive anatomy of the canine thorax was used to study magnetically induced currents in the myocardium. In this study, we simulated an applied magnetic field previously shown to cause irregular cardiac activity in canine experiments. We investigated the influence of model shape, conductive inhomogeneity, and anisotropy on the spatial distribution of the induced myocardial current density and its maximum (J/sub max/). Results suggest that shape, conductive inhomogeneity and anisotropy substantially influence myocardial current distributions and J/sub max/. Neglecting these factors yields results that substantially overestimate J/sub max/.<>
{"title":"Magnetically induced currents and fields in the canine heart: a finite element study","authors":"P. Ragan, S. Eisenberg, W. Wang","doi":"10.1109/IEMBS.1994.412024","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412024","url":null,"abstract":"A three-dimensional finite element model representing the conductive anatomy of the canine thorax was used to study magnetically induced currents in the myocardium. In this study, we simulated an applied magnetic field previously shown to cause irregular cardiac activity in canine experiments. We investigated the influence of model shape, conductive inhomogeneity, and anisotropy on the spatial distribution of the induced myocardial current density and its maximum (J/sub max/). Results suggest that shape, conductive inhomogeneity and anisotropy substantially influence myocardial current distributions and J/sub max/. Neglecting these factors yields results that substantially overestimate J/sub max/.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"48 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":"115792425","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.1994.415274
P. Basser, A. Grodzinsky
The authors characterize electrostatic and other polymer-polymer interactions within an ultracentrifuge cell using a new electrochemical transport model. Applying conservation of mass and momentum of solutes and solvent, and Maxwell's equations valid in the electroquasistatic limit, together with initial and boundary conditions on solute (and electrolyte) distribution, the authors predict the transient (nonequilibrium) and equilibrium solute (and electrolyte) distributions, net charge density, electric field, and electrostatic potential profiles. This model represents a significant advance ever the Lamm equation (and its extensions) (H. Fujita, 1962), which describe polymer-polymer interactions phenomenologically (using empirical virial coefficients) (L.W. Nichol et al., 1967).<>
{"title":"Electrostatic interactions between polyelectrolytes within an ultracentrifuge","authors":"P. Basser, A. Grodzinsky","doi":"10.1109/IEMBS.1994.415274","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415274","url":null,"abstract":"The authors characterize electrostatic and other polymer-polymer interactions within an ultracentrifuge cell using a new electrochemical transport model. Applying conservation of mass and momentum of solutes and solvent, and Maxwell's equations valid in the electroquasistatic limit, together with initial and boundary conditions on solute (and electrolyte) distribution, the authors predict the transient (nonequilibrium) and equilibrium solute (and electrolyte) distributions, net charge density, electric field, and electrostatic potential profiles. This model represents a significant advance ever the Lamm equation (and its extensions) (H. Fujita, 1962), which describe polymer-polymer interactions phenomenologically (using empirical virial coefficients) (L.W. Nichol et al., 1967).<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"83 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":"115842925","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.1994.415284
S. Nagarajan, D. Durand
The authors present a general theory for predicting transmembrane response along uniform finite length axons with arbitrary geometries and finite terminating impedances due to applied electric and magnetic fields. The transmembrane potential due to subthreshold applied electric and magnetic fields can be described using a generalized cable equation. The authors derive an integral expression for the subthreshold transmembrane potential by choosing a Green's function appropriate to the boundary conditions and configuration of the neuronal structure. Numerical evaluation of this integral expression can then be used to predict transmembrane response during electric and magnetic stimulation. The authors illustrate the usefulness of the theory with specific examples of stimulation of finite axons with arbitrary geometries, by electric and magnetic fields.<>
{"title":"A general theory for predicting subthreshold transmembrane response to electric and magnetic fields","authors":"S. Nagarajan, D. Durand","doi":"10.1109/IEMBS.1994.415284","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415284","url":null,"abstract":"The authors present a general theory for predicting transmembrane response along uniform finite length axons with arbitrary geometries and finite terminating impedances due to applied electric and magnetic fields. The transmembrane potential due to subthreshold applied electric and magnetic fields can be described using a generalized cable equation. The authors derive an integral expression for the subthreshold transmembrane potential by choosing a Green's function appropriate to the boundary conditions and configuration of the neuronal structure. Numerical evaluation of this integral expression can then be used to predict transmembrane response during electric and magnetic stimulation. The authors illustrate the usefulness of the theory with specific examples of stimulation of finite axons with arbitrary geometries, by electric and magnetic fields.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"135 52 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":"114370950","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.1994.412012
A. Erfanian, H. Chizeck, R. Hashemi
Reports the use of EMG signals obtained from surface electrodes to determine the knee joint angle in paraplegic subjects, when the quadriceps muscle is electrically stimulated using percutaneous intramuscular electrodes. Isometric conditions at different fixed joint angles were considered. Both time domain and frequency domain analysis methods were used to characterize the EMG-joint angle relationship. The power spectrum of the EMG was estimated by a high resolution parametric method.<>
{"title":"The relationship between joint angle and evoked EMG in electrically stimulated muscle","authors":"A. Erfanian, H. Chizeck, R. Hashemi","doi":"10.1109/IEMBS.1994.412012","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412012","url":null,"abstract":"Reports the use of EMG signals obtained from surface electrodes to determine the knee joint angle in paraplegic subjects, when the quadriceps muscle is electrically stimulated using percutaneous intramuscular electrodes. Isometric conditions at different fixed joint angles were considered. Both time domain and frequency domain analysis methods were used to characterize the EMG-joint angle relationship. The power spectrum of the EMG was estimated by a high resolution parametric method.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"101 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":"114969407","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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