Pub Date : 1993-10-28DOI: 10.1109/IEMBS.1993.978695
A. Bertuzzi, A. De Gaetano, A. Gandolfi, A. Greco, G. Mingrone, S. Salinari
The use of medium-chain dicarboxylic acjds, azelaic and sebacic acid, as energy substrates in total parenteral nutrition W M recently proposed [ 1 ,2 , since these acids may have metabolic advantages over long-chain and medium-chain triglycerides. However, a large amount of the administered dose of azelaic and sebacic acid is excreted in the urine, so that the suitability of these acids in parenteral nutrition appears to be doubtful in terms of energetic yield [3,4]. Encouraging results were obtained in rat with the dodecanedioic acid (C12), which presents very low urinary excretion 151. In this paper we analyze the data in ( 5 ) by inems of a pharmacokinetic model with saturable tissue uptake, using an estimation method that tnkes into account the interindividual variability of in ode1 par nine t ers .
{"title":"Pharmacokinetics of dodecanedioic acid in rat","authors":"A. Bertuzzi, A. De Gaetano, A. Gandolfi, A. Greco, G. Mingrone, S. Salinari","doi":"10.1109/IEMBS.1993.978695","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.978695","url":null,"abstract":"The use of medium-chain dicarboxylic acjds, azelaic and sebacic acid, as energy substrates in total parenteral nutrition W M recently proposed [ 1 ,2 , since these acids may have metabolic advantages over long-chain and medium-chain triglycerides. However, a large amount of the administered dose of azelaic and sebacic acid is excreted in the urine, so that the suitability of these acids in parenteral nutrition appears to be doubtful in terms of energetic yield [3,4]. Encouraging results were obtained in rat with the dodecanedioic acid (C12), which presents very low urinary excretion 151. In this paper we analyze the data in ( 5 ) by inems of a pharmacokinetic model with saturable tissue uptake, using an estimation method that tnkes into account the interindividual variability of in ode1 par nine t ers .","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"15 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124522546","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.978673
F. Tehrani
Premature infants very often suffer from respiratory disorders, and respiratory system failure is a major cause of fatality during infancy. An effective simulation model of the respiratory system can be a helpful tool in early and correct assessment of the neonate's respiratory distress. The purpose of this paper is to examine the response of a simulation model of the newborn infant's respiratory system. This model, whose performance has been successfully tested on healthy newborns under different physiological conditions, is used to predict respiratory responses of premature infants showing early signs of respiratory distress. Responses of the model have been illustrated in hypoxia and air breathing, as well as under supplemental oxygen treatment.
{"title":"Simulation and analysis of respiratory disorders of the premature infant","authors":"F. Tehrani","doi":"10.1109/IEMBS.1993.978673","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.978673","url":null,"abstract":"Premature infants very often suffer from respiratory disorders, and respiratory system failure is a major cause of fatality during infancy. An effective simulation model of the respiratory system can be a helpful tool in early and correct assessment of the neonate's respiratory distress. The purpose of this paper is to examine the response of a simulation model of the newborn infant's respiratory system. This model, whose performance has been successfully tested on healthy newborns under different physiological conditions, is used to predict respiratory responses of premature infants showing early signs of respiratory distress. Responses of the model have been illustrated in hypoxia and air breathing, as well as under supplemental oxygen treatment.","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126276495","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.979118
D. Tyler, D. Durand
Presented Is a new Intraneural electrode design capable of slowly placing electrodes between fasclcles of a nerve. The deslgn Is presented with prelimlnary resu l t s f rom acute s t lmula t lon experiments. The results demonstrate the ability o f the Radlally Penetratlng Interfascicular Nerve Electrode (RPINE) to fully penetrate the nerve within 24 hours without macroscopic damage or dlstort lon to the nerve. Stimulation results Indicates functlonal selectlvity with monopolar stlmulatlon. Combinatlons of monopoles generate v e c t o r addltlon of forces indlcatlng the ablllty to span moments space. The RPINE Is easy to fabricate, the implant procedure is simple, and the RPINE design Is sultable for chronlc Implant.
{"title":"Design and acute test of a radially penetrating interfascicular nerve electrode","authors":"D. Tyler, D. Durand","doi":"10.1109/IEMBS.1993.979118","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.979118","url":null,"abstract":"Presented Is a new Intraneural electrode design capable of slowly placing electrodes between fasclcles of a nerve. The deslgn Is presented with prelimlnary resu l t s f rom acute s t lmula t lon experiments. The results demonstrate the ability o f the Radlally Penetratlng Interfascicular Nerve Electrode (RPINE) to fully penetrate the nerve within 24 hours without macroscopic damage or dlstort lon to the nerve. Stimulation results Indicates functlonal selectlvity with monopolar stlmulatlon. Combinatlons of monopoles generate v e c t o r addltlon of forces indlcatlng the ablllty to span moments space. The RPINE Is easy to fabricate, the implant procedure is simple, and the RPINE design Is sultable for chronlc Implant.","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126508452","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.978773
G. R. Shaw, P. Savard
{"title":"Estimation of the alignment errors in the SAECG","authors":"G. R. Shaw, P. Savard","doi":"10.1109/IEMBS.1993.978773","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.978773","url":null,"abstract":"","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128066455","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.978585
P. Nunez, R. Wijesinghe, A. Westdorp, Guangcheng Cao, R. Silberstein, P. Cadusch
High resolution EEG methods based on the New Orleans spline Laplacinn and Melbourne cortical imaging algorithms are evaluated using simulated dipoles in four concentric spheres and finite element models of the head. The finite element models have realistic shapes and variable skull properties. Both methods arc shown to provide accurate estimates of cortical surface potcntial at scales down to about 2 or 3 cm when 64 or 118 electrodes are used. These approaches improve spntial resolution over that obtained with conventional EEG by a factor of about three.
{"title":"High resolution EEG: I. simulations","authors":"P. Nunez, R. Wijesinghe, A. Westdorp, Guangcheng Cao, R. Silberstein, P. Cadusch","doi":"10.1109/IEMBS.1993.978585","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.978585","url":null,"abstract":"High resolution EEG methods based on the New Orleans spline Laplacinn and Melbourne cortical imaging algorithms are evaluated using simulated dipoles in four concentric spheres and finite element models of the head. The finite element models have realistic shapes and variable skull properties. Both methods arc shown to provide accurate estimates of cortical surface potcntial at scales down to about 2 or 3 cm when 64 or 118 electrodes are used. These approaches improve spntial resolution over that obtained with conventional EEG by a factor of about three.","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128098644","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.979119
W. Grill, J. Mortimer
I. ~ T ~ ~ O D I J C ~ O N Electrical stimulation of the nervous system using implanted electrodes is a technique to restore sensory and motor functions to neurologically impaired persons. Using conventional stimuli (10-5OOpec rectangular current pulses) fibcrs lying closer to the electrode are recruited first, and larger amplitude currents are required to activate nerve fibers that lie further from the electrode. The threshold current for myelinated nerve fiber excitation is proportional to the square of the electrode-to-fiber distance at close eIecuode-lo-fiber spacings and proportional to the electrode-to-fiber distance at larger spacings (Fig. 1) [I]. We have developed and tested a multiple contact nerve cuff electrode to activate selectively discrete regions of peripheral nerve trunks for neural prosthetic applications [51. The elcccrode allows selective and graded activation of fascicles located on the periphery of the nerve trunk, but does not yet allow selective activation of centrally located nerve fibers. The goal of this work was rhus to develop a method 10 activate selectively fibers at some distance from the electrode without activaung the fibers close to the electrode. We hypothesized that, by using novel pulse waveforms, we could manipulate the non-linear properries of the nerve membrane to elevate threshold for fibers lying close to the electrode. The diameter of the model nerve fiber was set at either 10Fm or 2 0 p U) span the range of diameters of a-motoneurons. The nerve fiber was assumed to lie i n a homogeneous isotropic medium (p=55 R-cm), and the electrode was modeled as a point source at different distances above the center compartment of the 21 compartment cable. The response of the fiber (i.e., the transmembrane voltage) to an extracellular current stimulus was solved as a function of time using fourth order Runge-Kutta integration. Threshold stk"us current for generation of an action potential with differen; waveforms was calculated (+l% error) for each fiber diameter as a function of the electrode-to-fiber dismce. In. RESULTS A. Current-Distance Reldionrhip for Short-Duraion Pulses In Fig. 1 is shown the threshold current as a function of ihe electrode-to-fiber spacing for lOpm and 2 O p nerve fibcrs when the stimulus was a 500psec rectangular cathodic current pulse (inset). Fibers that were further from the electrode required more current to excite, as expected. Very close to the electrode there was little difference between the thresholds of the lOpm and 20pm nerve fibers. but beyond 0.5" substantially more current was required to excite the 10" fiber than the 2Opn fiber. 11. METHODS A cable model of a mammalian myelinated axon [4] was uscd to study the effects of different waveforms on the excitabilily of axons. The parameters of the model are based on voltage clamp data from rat and rabbit myelinated axons, and the model represents accurately rhe shape and conduction velocity of a mammalian action potential at 37°C
{"title":"Selective activation of distant nerve fibers","authors":"W. Grill, J. Mortimer","doi":"10.1109/IEMBS.1993.979119","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.979119","url":null,"abstract":"I. ~ T ~ ~ O D I J C ~ O N Electrical stimulation of the nervous system using implanted electrodes is a technique to restore sensory and motor functions to neurologically impaired persons. Using conventional stimuli (10-5OOpec rectangular current pulses) fibcrs lying closer to the electrode are recruited first, and larger amplitude currents are required to activate nerve fibers that lie further from the electrode. The threshold current for myelinated nerve fiber excitation is proportional to the square of the electrode-to-fiber distance at close eIecuode-lo-fiber spacings and proportional to the electrode-to-fiber distance at larger spacings (Fig. 1) [I]. We have developed and tested a multiple contact nerve cuff electrode to activate selectively discrete regions of peripheral nerve trunks for neural prosthetic applications [51. The elcccrode allows selective and graded activation of fascicles located on the periphery of the nerve trunk, but does not yet allow selective activation of centrally located nerve fibers. The goal of this work was rhus to develop a method 10 activate selectively fibers at some distance from the electrode without activaung the fibers close to the electrode. We hypothesized that, by using novel pulse waveforms, we could manipulate the non-linear properries of the nerve membrane to elevate threshold for fibers lying close to the electrode. The diameter of the model nerve fiber was set at either 10Fm or 2 0 p U) span the range of diameters of a-motoneurons. The nerve fiber was assumed to lie i n a homogeneous isotropic medium (p=55 R-cm), and the electrode was modeled as a point source at different distances above the center compartment of the 21 compartment cable. The response of the fiber (i.e., the transmembrane voltage) to an extracellular current stimulus was solved as a function of time using fourth order Runge-Kutta integration. Threshold stk\"us current for generation of an action potential with differen; waveforms was calculated (+l% error) for each fiber diameter as a function of the electrode-to-fiber dismce. In. RESULTS A. Current-Distance Reldionrhip for Short-Duraion Pulses In Fig. 1 is shown the threshold current as a function of ihe electrode-to-fiber spacing for lOpm and 2 O p nerve fibcrs when the stimulus was a 500psec rectangular cathodic current pulse (inset). Fibers that were further from the electrode required more current to excite, as expected. Very close to the electrode there was little difference between the thresholds of the lOpm and 20pm nerve fibers. but beyond 0.5\" substantially more current was required to excite the 10\" fiber than the 2Opn fiber. 11. METHODS A cable model of a mammalian myelinated axon [4] was uscd to study the effects of different waveforms on the excitabilily of axons. The parameters of the model are based on voltage clamp data from rat and rabbit myelinated axons, and the model represents accurately rhe shape and conduction velocity of a mammalian action potential at 37°C","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125431863","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.978969
A. M. Lebar, G. Harris, J. Wertsch, H. Zhu
We have developed a circular ( 1 5 m in diameter x 3.8mm thick) shear force sensing transducer consisting of two circular metal discs and two flat springs to measure the shear between the plantar surface and insole during ambulation. Shear force causes the top disc to move in the direction of the applied force. This movement forces a wedge, located on the top disc, to either increase or decrease the amount of light transmitted from an LED to a photodiode, rela&ive to a change in the applied shear force. The operatiug range was from 0 to 22.3N shear, and could be altered by adjusting the metal spring stiffness and dimensions. The two transducer discs were assembled and bonded with silicone adhesive. Placement of the sensor into an insole allowed measurement of shear forces under the human foot during normal gait.
{"title":"Development of a miniature plantar shear force sensing transducer","authors":"A. M. Lebar, G. Harris, J. Wertsch, H. Zhu","doi":"10.1109/IEMBS.1993.978969","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.978969","url":null,"abstract":"We have developed a circular ( 1 5 m in diameter x 3.8mm thick) shear force sensing transducer consisting of two circular metal discs and two flat springs to measure the shear between the plantar surface and insole during ambulation. Shear force causes the top disc to move in the direction of the applied force. This movement forces a wedge, located on the top disc, to either increase or decrease the amount of light transmitted from an LED to a photodiode, rela&ive to a change in the applied shear force. The operatiug range was from 0 to 22.3N shear, and could be altered by adjusting the metal spring stiffness and dimensions. The two transducer discs were assembled and bonded with silicone adhesive. Placement of the sensor into an insole allowed measurement of shear forces under the human foot during normal gait.","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125590124","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.978632
R. Silberstein, P. Cadusch, P. Nunez, R. Wijesinghe, R. Srinivasan
{"title":"High resolution EEG: II. application to spontaneous EEG","authors":"R. Silberstein, P. Cadusch, P. Nunez, R. Wijesinghe, R. Srinivasan","doi":"10.1109/IEMBS.1993.978632","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.978632","url":null,"abstract":"","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121936626","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.978745
F. Forster, J.Y.J. Yan, R. Johnson, S. Gu
{"title":"A cardiac output estimation algorithm for a catheter-based cold-fluid heat exchanger system","authors":"F. Forster, J.Y.J. Yan, R. Johnson, S. Gu","doi":"10.1109/IEMBS.1993.978745","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.978745","url":null,"abstract":"","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121946660","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 : 1993-10-28DOI: 10.1109/IEMBS.1993.978581
J. Varner, J. Rohrbaugh
The ability to correct for ocular artifacts in EEG signals recorded during the course of event-related potential experiments is of major importance. The basic principle used when correcting ERP's with recorded EOG signals is to consider the ocular artifacts as a linear combination of the measured EOG signals and to subtract these ocular artifacts from the measured ERP signals. This pcrper describes a simplified method for calculating EOG correction coefficients for eye blinks. Preliminary resu l t s of applying this technique to the EEG data of seven children have shown a significant increase in the number of usable trials available for computing averages.
{"title":"A simple technique for eye blink correction","authors":"J. Varner, J. Rohrbaugh","doi":"10.1109/IEMBS.1993.978581","DOIUrl":"https://doi.org/10.1109/IEMBS.1993.978581","url":null,"abstract":"The ability to correct for ocular artifacts in EEG signals recorded during the course of event-related potential experiments is of major importance. The basic principle used when correcting ERP's with recorded EOG signals is to consider the ocular artifacts as a linear combination of the measured EOG signals and to subtract these ocular artifacts from the measured ERP signals. This pcrper describes a simplified method for calculating EOG correction coefficients for eye blinks. Preliminary resu l t s of applying this technique to the EEG data of seven children have shown a significant increase in the number of usable trials available for computing averages.","PeriodicalId":408657,"journal":{"name":"Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122256135","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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