Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.411849
S. A. Jones
It has been noted previously that Doppler ultrasound measurements from a coronary guidewire in a circular tube exhibited spectral peaks which were not directly related to hemodynamic phenomena. These peaks were more pronounced with an increase in the acoustic impedance mismatch between the tube walls and the fluid. To determine whether these peaks could be explained by mismatch-induced beam-pattern distortion, the beam pattern of an ultrasound probe inside a circular tube was measured and was used to simulate the Doppler spectrum which would result from Poiseuille flow. The resulting spectra had peaks similar in size to those from guidewire measurements in Poiseuille flow.<>
{"title":"Distortion of Doppler ultrasound beam patterns caused by acoustic impedance mismatch at vessel interfaces","authors":"S. A. Jones","doi":"10.1109/IEMBS.1994.411849","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411849","url":null,"abstract":"It has been noted previously that Doppler ultrasound measurements from a coronary guidewire in a circular tube exhibited spectral peaks which were not directly related to hemodynamic phenomena. These peaks were more pronounced with an increase in the acoustic impedance mismatch between the tube walls and the fluid. To determine whether these peaks could be explained by mismatch-induced beam-pattern distortion, the beam pattern of an ultrasound probe inside a circular tube was measured and was used to simulate the Doppler spectrum which would result from Poiseuille flow. The resulting spectra had peaks similar in size to those from guidewire measurements in Poiseuille flow.<<ETX>>","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":"134381873","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.1994.411866
Y. Erdi, M. Loew, A. Erdi, B. Wessels
A median filtered pyramidal multiresolution (MFPM) image segmentation method for detecting and delineating compact objects was applied to single-photon emission computed tomography (SPECT) images. These SPECT images were obtained by scanning spheres from 1 to 54 ml in size and from 50% to 100% contrast settings. The algorithm performed accurately for large sphere (20 and 54 ml) and high contrast (90% and 100%) cases. As the size and contrast decrease, the accuracy of the method also decreases. Comparison of the MFPM method with adaptive thresholding with edge-preserving smoothing (ATEPS) indicated superior performance of the MFPM method.<>
{"title":"Pyramidal multiresolution image segmentation in SPECT","authors":"Y. Erdi, M. Loew, A. Erdi, B. Wessels","doi":"10.1109/IEMBS.1994.411866","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411866","url":null,"abstract":"A median filtered pyramidal multiresolution (MFPM) image segmentation method for detecting and delineating compact objects was applied to single-photon emission computed tomography (SPECT) images. These SPECT images were obtained by scanning spheres from 1 to 54 ml in size and from 50% to 100% contrast settings. The algorithm performed accurately for large sphere (20 and 54 ml) and high contrast (90% and 100%) cases. As the size and contrast decrease, the accuracy of the method also decreases. Comparison of the MFPM method with adaptive thresholding with edge-preserving smoothing (ATEPS) indicated superior performance of the MFPM method.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"76 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":"131766002","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.1994.415454
S. Schiff
Simple neuronal circuits from both spinal cord and brain are studied as both input-output systems and when spontaneously active. The authors have employed nonlinear prediction techniques to test for the presence for determinism in such circuitry. In addition, the authors have employed a technique of chaos control successfully on a model epileptic focus.
{"title":"Determinism and the prospect of control of simple neuronal systems","authors":"S. Schiff","doi":"10.1109/IEMBS.1994.415454","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415454","url":null,"abstract":"Simple neuronal circuits from both spinal cord and brain are studied as both input-output systems and when spontaneously active. The authors have employed nonlinear prediction techniques to test for the presence for determinism in such circuitry. In addition, the authors have employed a technique of chaos control successfully on a model epileptic focus.","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"2 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":"129387012","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.1994.411940
R. Cooper
The observability and controllability of a scooter with a human pilot is examined with respect to directional changes. This model can be used to reduce the effects of outside disturbances on direction, and to examine the abilities of the user required to effectively drive a scooter. Scooters are common mobility devices used by people with physical impairments, or elderly people. Scooters use manual steering via a lever or handle-bar. A linearized model based on ground track kinematics, user characteristics, and environmental conditions was examined. This model was completely observable and controllable.<>
{"title":"Observability and controllability of scooters","authors":"R. Cooper","doi":"10.1109/IEMBS.1994.411940","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411940","url":null,"abstract":"The observability and controllability of a scooter with a human pilot is examined with respect to directional changes. This model can be used to reduce the effects of outside disturbances on direction, and to examine the abilities of the user required to effectively drive a scooter. Scooters are common mobility devices used by people with physical impairments, or elderly people. Scooters use manual steering via a lever or handle-bar. A linearized model based on ground track kinematics, user characteristics, and environmental conditions was examined. This model was completely observable and controllable.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"26 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":"125242818","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.1994.412151
W. Chen, R.C. Lee
Summary form only given as follows: In addition to electroporation of cell membranes, the authors have also shown shock pulse-induced reduction in voltage-gated ionic channel conductance and channel selectivity, which suggests possible electroconformational changes in proteins of the cell membrane. Therefore, the authors are now attempting to locate the damage in the protein structure. Some of their evidence suggests that the most vulnerable subgroups of channel proteins are located at the narrowest pore of the channels. Experiments were performed using an improved double vaseline-gap voltage and current clamp technique with cut fibers from skeletal muscle of the frog Rana temporaria. The experimental results showed that: 1) the binding of the neurotoxins TIX and TEA on sodium (Na) and potassium (K) channels are not affected by the high voltage electrical shock pulses; 2) the inactivity curve of the delayed rectifier K channel shows little change following electric shock; and 3) K channel conductance and ionic selectivity can be significantly reduced by the electric shock pulse, predicting a depolarization of the membrane resting potential, which has been further proved by directly measuring membrane potential response to an electrical shock. The figure below shows the shock pulse-induced depolarization of the membrane resting potential. Combining these functional alterations of channel proteins, it is possible to answer the question of what subgroups of the channel proteins are the most sensitive to a high voltage electrical shock. The neurotoxin binding sites of TTX and TEA are most likely located on the peripheral residue of the channel proteins not in the narrowest pore of the selectivity filter. Similarly, the well-accepted hypothesis of the channel inactivity suggests that channel inactivity function be correlated to the amino-terminal residues, which are intracellularly located away from the selectivity filter. In contrast, reduction of channel conductance and ionic selectivity are primarily correlated to the narrowest pore of the channels, the selectivity filter. In other words, the narrowest pore of the ion channel with a diameter of a few /spl Aring/ is the most sensitive subgroup to the external electrical field.<>
{"title":"Electro-mediated damage in the narrowest pore of voltage-gated K channels in frog skeletal muscle membrane","authors":"W. Chen, R.C. Lee","doi":"10.1109/IEMBS.1994.412151","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412151","url":null,"abstract":"Summary form only given as follows: In addition to electroporation of cell membranes, the authors have also shown shock pulse-induced reduction in voltage-gated ionic channel conductance and channel selectivity, which suggests possible electroconformational changes in proteins of the cell membrane. Therefore, the authors are now attempting to locate the damage in the protein structure. Some of their evidence suggests that the most vulnerable subgroups of channel proteins are located at the narrowest pore of the channels. Experiments were performed using an improved double vaseline-gap voltage and current clamp technique with cut fibers from skeletal muscle of the frog Rana temporaria. The experimental results showed that: 1) the binding of the neurotoxins TIX and TEA on sodium (Na) and potassium (K) channels are not affected by the high voltage electrical shock pulses; 2) the inactivity curve of the delayed rectifier K channel shows little change following electric shock; and 3) K channel conductance and ionic selectivity can be significantly reduced by the electric shock pulse, predicting a depolarization of the membrane resting potential, which has been further proved by directly measuring membrane potential response to an electrical shock. The figure below shows the shock pulse-induced depolarization of the membrane resting potential. Combining these functional alterations of channel proteins, it is possible to answer the question of what subgroups of the channel proteins are the most sensitive to a high voltage electrical shock. The neurotoxin binding sites of TTX and TEA are most likely located on the peripheral residue of the channel proteins not in the narrowest pore of the selectivity filter. Similarly, the well-accepted hypothesis of the channel inactivity suggests that channel inactivity function be correlated to the amino-terminal residues, which are intracellularly located away from the selectivity filter. In contrast, reduction of channel conductance and ionic selectivity are primarily correlated to the narrowest pore of the channels, the selectivity filter. In other words, the narrowest pore of the ion channel with a diameter of a few /spl Aring/ is the most sensitive subgroup to the external electrical field.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"12 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":"131210506","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.1994.415494
P.O. El Guedj, P. Nugues
We describe a natural language parser for large medical corpora. Sentence parsing is a necessary step to build a sentence representation and to support a wide-coverage semantic interpretation. When applied to limited domains, a good syntax coverage can be obtained from Phrase-Structure rules. Large medical corpora show a strong variability in word and phrase order that requires more specific parsing strategies. We describe a parser based on Chart techniques. It parses constituents from left to right as they appear in a sentence. It enables the incremental partial parsing of words and phrases coming from a speech recognition input. We report here first results obtained from a large corpus of cancer treatment reports.
{"title":"A chart parser to analyze large medical corpora","authors":"P.O. El Guedj, P. Nugues","doi":"10.1109/IEMBS.1994.415494","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415494","url":null,"abstract":"We describe a natural language parser for large medical corpora. Sentence parsing is a necessary step to build a sentence representation and to support a wide-coverage semantic interpretation. When applied to limited domains, a good syntax coverage can be obtained from Phrase-Structure rules. Large medical corpora show a strong variability in word and phrase order that requires more specific parsing strategies. We describe a parser based on Chart techniques. It parses constituents from left to right as they appear in a sentence. It enables the incremental partial parsing of words and phrases coming from a speech recognition input. We report here first results obtained from a large corpus of cancer treatment reports.","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"70 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":"132992930","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.1994.415152
J. McLaughlin, E. T. McAdams, J. Anderson
A new 12-lead transtelephonic ECG electrode system has been developed by NIBEC. The dry electrode system consists of an, Ag/AgCl screenprinted ink layer patterned on to a flexible 125 /spl mu/m polyester film. This has been hydro-formed in order to ensure good skin contact and high quality signal sensing. The sensors are used as a reusable electrode system for home-based use in transtelephonic ECG monitoring of patients.<>
{"title":"Novel dry electrode ECG sensor system","authors":"J. McLaughlin, E. T. McAdams, J. Anderson","doi":"10.1109/IEMBS.1994.415152","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415152","url":null,"abstract":"A new 12-lead transtelephonic ECG electrode system has been developed by NIBEC. The dry electrode system consists of an, Ag/AgCl screenprinted ink layer patterned on to a flexible 125 /spl mu/m polyester film. This has been hydro-formed in order to ensure good skin contact and high quality signal sensing. The sensors are used as a reusable electrode system for home-based use in transtelephonic ECG monitoring of patients.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"429 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":"133088086","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.1994.411954
J. Fee
Reports on the use of a passive, second order non-linear model of the leg drop pendulum test as a means of gaining insight into a therapeutic intervention in spastic cerebral palsy. Optimization techniques are used to adjust model parameters, such that model data fits actual data. Actual data is taken from a set of triplets, two of which have varying degrees of spastic cerebral palsy and one is without disability. The author compares five sets of data, one from the normal triplet and two each from the subjects with spasticity. Data from the subjects with spasticity is taken before and after vertical stimulation similar to that which one would receive while on horseback. The model parameters show several trends. First, stiffness and dampening coefficients are higher in the models of the disabled subjects' data than the normal subjects. Second, these coefficients change, becoming more like the normal subject's coefficients after vertical accelerations.<>
{"title":"A non-linear, passive, model of the leg drop pendulum test: assessing changes in spastic cerebral palsy after vertical accelerations","authors":"J. Fee","doi":"10.1109/IEMBS.1994.411954","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411954","url":null,"abstract":"Reports on the use of a passive, second order non-linear model of the leg drop pendulum test as a means of gaining insight into a therapeutic intervention in spastic cerebral palsy. Optimization techniques are used to adjust model parameters, such that model data fits actual data. Actual data is taken from a set of triplets, two of which have varying degrees of spastic cerebral palsy and one is without disability. The author compares five sets of data, one from the normal triplet and two each from the subjects with spasticity. Data from the subjects with spasticity is taken before and after vertical stimulation similar to that which one would receive while on horseback. The model parameters show several trends. First, stiffness and dampening coefficients are higher in the models of the disabled subjects' data than the normal subjects. Second, these coefficients change, becoming more like the normal subject's coefficients after vertical accelerations.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"257 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":"133497014","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.1994.412001
R.A. Jesinger, V. Stonick
Presents a new technique for reconstruction and imaging of volumetric neuromuscular activity using digital signal processing of multichannel surface potential recordings. Magnetic resonance imaging is used to chart anatomical structures and quantify material permittivity within the inhomogenous volume. Array signal processing is used localize neuromuscular action potentials based on the available anatomical and electromyographic measurements. Poisson's equation is then solved using finite element methods coupled with signal processing estimation techniques. This new imaging tool can greatly enhance clinical diagnosis and treatment of neuromuscular injuries and disorders by localizing pathological signals within muscle.<>
{"title":"Imaging of neuromuscular potentials using noninvasive electrode array processing","authors":"R.A. Jesinger, V. Stonick","doi":"10.1109/IEMBS.1994.412001","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412001","url":null,"abstract":"Presents a new technique for reconstruction and imaging of volumetric neuromuscular activity using digital signal processing of multichannel surface potential recordings. Magnetic resonance imaging is used to chart anatomical structures and quantify material permittivity within the inhomogenous volume. Array signal processing is used localize neuromuscular action potentials based on the available anatomical and electromyographic measurements. Poisson's equation is then solved using finite element methods coupled with signal processing estimation techniques. This new imaging tool can greatly enhance clinical diagnosis and treatment of neuromuscular injuries and disorders by localizing pathological signals within muscle.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"4 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":"132440424","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.1994.411900
P. Basser, J. Mattiello, C. Pierpaoli, D. LeBihan
Diffusion tensor imaging (DTI) provides intravoxel microstructural and microdynamic information about tissues that reflects their physiological state. The authors use DTI to assess changes in water mobility in an in vivo model of cerebral ischemia in cats. They use four estimated scalar quantities: the 3 principal diffusivities (/spl lambda//sub 1/, /spl lambda//sub 2/, and /spl lambda//sub 3/) and the T/sub 2/-weighted NMR signal (A(0)), as features with which to segment both normal and pathological tissues. While the authors can use these parameters to discriminate between normal and ischemic white and gray matter in cats, they are evaluating their use to distinguish between reversibly and irreversibly damaged tissues during stroke and other white matter diseases.<>
{"title":"MR diffusion tensor imaging of ischemic brain in vivo","authors":"P. Basser, J. Mattiello, C. Pierpaoli, D. LeBihan","doi":"10.1109/IEMBS.1994.411900","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411900","url":null,"abstract":"Diffusion tensor imaging (DTI) provides intravoxel microstructural and microdynamic information about tissues that reflects their physiological state. The authors use DTI to assess changes in water mobility in an in vivo model of cerebral ischemia in cats. They use four estimated scalar quantities: the 3 principal diffusivities (/spl lambda//sub 1/, /spl lambda//sub 2/, and /spl lambda//sub 3/) and the T/sub 2/-weighted NMR signal (A(0)), as features with which to segment both normal and pathological tissues. While the authors can use these parameters to discriminate between normal and ischemic white and gray matter in cats, they are evaluating their use to distinguish between reversibly and irreversibly damaged tissues during stroke and other white matter diseases.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"17 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":"133142346","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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