Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.575309
R. Mongrain, M. Bertrand, K. Kandarpa
The authors propose a numerical model to simulate the main physical processes occurring during catheter injection: blood dynamics is taken into account with the Navier-Stokes equations and the substance dispersion by the flowing blood with the advection diffusion equation. The model reproduces in vitro observations and allows one to evaluate some mixing properties of various catheter designs in different flow conditions.
{"title":"Study of catheter designs for infusion procedures using numerical simulations","authors":"R. Mongrain, M. Bertrand, K. Kandarpa","doi":"10.1109/IEMBS.1995.575309","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575309","url":null,"abstract":"The authors propose a numerical model to simulate the main physical processes occurring during catheter injection: blood dynamics is taken into account with the Navier-Stokes equations and the substance dispersion by the flowing blood with the advection diffusion equation. The model reproduces in vitro observations and allows one to evaluate some mixing properties of various catheter designs in different flow conditions.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77494304","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.579518
J. Smit, W. Rutten
A two-dimensional 24-channel wire-microelectrode array was inserted into the peroneal nerve of the rat during acute experiments. The electrodes in the array are on a regular grid of 6 by 4 electrodes; inter-electrode spacing is 120 /spl mu/m. For each of the electrodes in the array the corresponding twitch-force recruitment curve was recorded from the extensor digitorum longus muscle (EDL). A complete set of 24 recruitment curves is presented The shape of the recruitment curves varies among the electrodes in the array. This supports previous findings which suggest a different motor unit recruitment order for stimulating electrodes at different intraneural positions.
{"title":"Intraneural stimulation using 2D wire-microelectrode arrays. I. Experimental results","authors":"J. Smit, W. Rutten","doi":"10.1109/IEMBS.1995.579518","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579518","url":null,"abstract":"A two-dimensional 24-channel wire-microelectrode array was inserted into the peroneal nerve of the rat during acute experiments. The electrodes in the array are on a regular grid of 6 by 4 electrodes; inter-electrode spacing is 120 /spl mu/m. For each of the electrodes in the array the corresponding twitch-force recruitment curve was recorded from the extensor digitorum longus muscle (EDL). A complete set of 24 recruitment curves is presented The shape of the recruitment curves varies among the electrodes in the array. This supports previous findings which suggest a different motor unit recruitment order for stimulating electrodes at different intraneural positions.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77877103","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.579899
J. Harding
Preliminary assessment of clinically suspected deep venous thrombosis (DVT) of the lower limb by thermography avoids the need for over one third of venograms or duplex Doppler ultrasound scans. Clinical diagnosis of DVT is notoriously unreliable-hence the need for an accurate means of clinical investigation. Untreated DVT is dangerous as it can progress to pulmonary embolism (PE) which is frequently fatal or life-threatening. Treatment of DVT by anticoagulation poses risks of its own however, and should not be undertaken without a confirmed diagnosis. Thermal imaging is quick, simple, noninvasive, risk-free, cost-effective and highly sensitive in the initial investigation of suspected DVT; a negative thermogram excludes DVT and avoids the necessity for further investigation. Thermal imaging is, however, non-specific; a positive thermogram has a number of possible causes and is an indication for further assessment by venography or Doppler ultrasound to confirm or exclude DVT. Thermography should be considered the initial investigation of choice in clinically suspected DVT, proceeding to venography or Doppler ultrasound only when thermography is positive.
{"title":"Thermal imaging in the investigation of deep venous thrombosis","authors":"J. Harding","doi":"10.1109/IEMBS.1995.579899","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579899","url":null,"abstract":"Preliminary assessment of clinically suspected deep venous thrombosis (DVT) of the lower limb by thermography avoids the need for over one third of venograms or duplex Doppler ultrasound scans. Clinical diagnosis of DVT is notoriously unreliable-hence the need for an accurate means of clinical investigation. Untreated DVT is dangerous as it can progress to pulmonary embolism (PE) which is frequently fatal or life-threatening. Treatment of DVT by anticoagulation poses risks of its own however, and should not be undertaken without a confirmed diagnosis. Thermal imaging is quick, simple, noninvasive, risk-free, cost-effective and highly sensitive in the initial investigation of suspected DVT; a negative thermogram excludes DVT and avoids the necessity for further investigation. Thermal imaging is, however, non-specific; a positive thermogram has a number of possible causes and is an indication for further assessment by venography or Doppler ultrasound to confirm or exclude DVT. Thermography should be considered the initial investigation of choice in clinically suspected DVT, proceeding to venography or Doppler ultrasound only when thermography is positive.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80485082","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.579716
P. Boissy, P. Pigeon, A. Arsenault, D. Gravel, D. Bourbonnais
EMG power spectrums of biceps brachii (BE) and triceps brachii (TB) when acting as antagonists were obtained during linearly increasing force ramp contractions. Mean BB median frequency (MF) shifted downward with increasing force levels up to 100% maximal voluntary contraction (MVC), possibly indicating a derecruitment of BB motor units. Polynomial regression between signal to noise ratios (SNRs) and MFs [r=0.94] of BB showed that at low force levels (10-40% MVC) large MF shifts are associated with a short range of small SNRs. This suggests that the initial large MF values of BB may be due to the high frequency content of heat noise and that the previously proposed derecruitment of motor units might not be solely responsible for the initial MF decrease.
{"title":"EMG power spectrum shifts of biceps brachii when acting as an antagonist","authors":"P. Boissy, P. Pigeon, A. Arsenault, D. Gravel, D. Bourbonnais","doi":"10.1109/IEMBS.1995.579716","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579716","url":null,"abstract":"EMG power spectrums of biceps brachii (BE) and triceps brachii (TB) when acting as antagonists were obtained during linearly increasing force ramp contractions. Mean BB median frequency (MF) shifted downward with increasing force levels up to 100% maximal voluntary contraction (MVC), possibly indicating a derecruitment of BB motor units. Polynomial regression between signal to noise ratios (SNRs) and MFs [r=0.94] of BB showed that at low force levels (10-40% MVC) large MF shifts are associated with a short range of small SNRs. This suggests that the initial large MF values of BB may be due to the high frequency content of heat noise and that the previously proposed derecruitment of motor units might not be solely responsible for the initial MF decrease.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84439399","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.579777
S. Wolpert
A comprehensive neuromime realized in CMOS VLSI circuitry was used to reconstruct and parametrically test the cellular oscillator that gives rise to swimming motion in hirudo, the medicinal leech. Each subunit of the leech swim network consists of a number of embedded cyclic and reciprocal sub-oscillators. Tests on the two sub-oscillator types indicate that the cellular and environmental parameters to which they are most immune complement one another. Tests on an entire subunit of the leech network show that the overall stability of the network is attributable to the product of the stability of its sub-oscillators.
{"title":"Parametric stability in a cellular oscillator","authors":"S. Wolpert","doi":"10.1109/IEMBS.1995.579777","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579777","url":null,"abstract":"A comprehensive neuromime realized in CMOS VLSI circuitry was used to reconstruct and parametrically test the cellular oscillator that gives rise to swimming motion in hirudo, the medicinal leech. Each subunit of the leech swim network consists of a number of embedded cyclic and reciprocal sub-oscillators. Tests on the two sub-oscillator types indicate that the cellular and environmental parameters to which they are most immune complement one another. Tests on an entire subunit of the leech network show that the overall stability of the network is attributable to the product of the stability of its sub-oscillators.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84896173","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.579818
S. Eck, A. Bolt, M. Schaldach
Phosphorus doped silicon carbide thin films are produced by plasma enhanced chemical vapor deposition (PECVD) to be used for integrated resistor arrays applied in electronic implants for electrotherapy. A DC magnetron sputtered aluminum film serves as the metallization layer. Depending on the deposition and annealing parameters the electrical properties of the amorphous or microcrystalline films can be varied over several orders of magnitude. With regard to the tolerable temperature coefficient (TCR) of 500 ppm/K the maximum sheet resistance (R/sub s/) is 2 k/spl Omega//sub /spl square// up to now. The patterning of the silicon carbide/aluminum system is done by a conventional 5 /spl mu/m-lithography and etch process resulting in an integration density of 40 M/spl Omega//mm/sup 2/. The applied thin film techniques prove to be more reliable and reproducible than the thick film processes used so far.
{"title":"Integrated thin film resistor arrays for electronic implants based on microcrystalline silicon carbide","authors":"S. Eck, A. Bolt, M. Schaldach","doi":"10.1109/IEMBS.1995.579818","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579818","url":null,"abstract":"Phosphorus doped silicon carbide thin films are produced by plasma enhanced chemical vapor deposition (PECVD) to be used for integrated resistor arrays applied in electronic implants for electrotherapy. A DC magnetron sputtered aluminum film serves as the metallization layer. Depending on the deposition and annealing parameters the electrical properties of the amorphous or microcrystalline films can be varied over several orders of magnitude. With regard to the tolerable temperature coefficient (TCR) of 500 ppm/K the maximum sheet resistance (R/sub s/) is 2 k/spl Omega//sub /spl square// up to now. The patterning of the silicon carbide/aluminum system is done by a conventional 5 /spl mu/m-lithography and etch process resulting in an integration density of 40 M/spl Omega//mm/sup 2/. The applied thin film techniques prove to be more reliable and reproducible than the thick film processes used so far.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85581668","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.575254
C. Cohen-Bacrie, Y. Goussard
This paper presents a new regularization approach to the ill-posed inverse problem of electrical impedance tomography (EIT). The main focus of the communication is on the choice of the regularization matrix and of the regularization parameters. To select the regularization matrix the authors use a variance uniformization criterion so as to distribute uniformly the effect of the measurement noise over the whole estimate. Then, adequate values of the regularization parameters are determined from the observed data using ordinary cross validation (OCV). For practical reasons, linearized equations of the direct problem are used in this study. However, the technique can be extended to methods that solve the nonlinear direct problem in an iterative manner.
{"title":"Electrical impedance tomography: regularized reconstruction using a variance uniformization constraint","authors":"C. Cohen-Bacrie, Y. Goussard","doi":"10.1109/IEMBS.1995.575254","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575254","url":null,"abstract":"This paper presents a new regularization approach to the ill-posed inverse problem of electrical impedance tomography (EIT). The main focus of the communication is on the choice of the regularization matrix and of the regularization parameters. To select the regularization matrix the authors use a variance uniformization criterion so as to distribute uniformly the effect of the measurement noise over the whole estimate. Then, adequate values of the regularization parameters are determined from the observed data using ordinary cross validation (OCV). For practical reasons, linearized equations of the direct problem are used in this study. However, the technique can be extended to methods that solve the nonlinear direct problem in an iterative manner.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76847339","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.579498
G. Henning, O. Hoenecke, P. Husar, K. Schellhorn, U. Trautwein
Knowing the properties of the EEG-signal related to a visual stimulus is of fundamental importance for an adequate design of a signal detection method, e.g. In objective sensory function diagnostics. From a signal-theoretical point of view the steady state visual evoked response (VER), but under physiological aspects the transient VER seems to be more appropriate for reliable signal detection. A stimulation with flicker-bursts is proposed combining both methods. The EEG/VER-signals have been analyzed with different methods of time-frequency analysis: spectrogram, pseudo-Wigner distribution, cone-kernel representation, reduced-interference distribution are applied to real signals. Concerning feature extraction of the stimulus-method, the reduced-interference distribution offers the best properties.
{"title":"Time-frequency analysis of flicker-burst visual evoked responses","authors":"G. Henning, O. Hoenecke, P. Husar, K. Schellhorn, U. Trautwein","doi":"10.1109/IEMBS.1995.579498","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579498","url":null,"abstract":"Knowing the properties of the EEG-signal related to a visual stimulus is of fundamental importance for an adequate design of a signal detection method, e.g. In objective sensory function diagnostics. From a signal-theoretical point of view the steady state visual evoked response (VER), but under physiological aspects the transient VER seems to be more appropriate for reliable signal detection. A stimulation with flicker-bursts is proposed combining both methods. The EEG/VER-signals have been analyzed with different methods of time-frequency analysis: spectrogram, pseudo-Wigner distribution, cone-kernel representation, reduced-interference distribution are applied to real signals. Concerning feature extraction of the stimulus-method, the reduced-interference distribution offers the best properties.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76909912","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.575286
Fansan Zhu, Su Tan, Jarui Lin, Xiaohai Gao, Yuli Zhou
A new method of electric pulse treatment (EPT) for cancer is presented. The methods used in animal experiments and for clinical studies of esophageal cancer treatment are described. The results show that the techniques of electric pulse treatment for cancer have produced success in both 34 rats and 6 cases of esophageal cancer.
{"title":"Experiment and application of electrochemical treatment for cancer with electric pulses","authors":"Fansan Zhu, Su Tan, Jarui Lin, Xiaohai Gao, Yuli Zhou","doi":"10.1109/IEMBS.1995.575286","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575286","url":null,"abstract":"A new method of electric pulse treatment (EPT) for cancer is presented. The methods used in animal experiments and for clinical studies of esophageal cancer treatment are described. The results show that the techniques of electric pulse treatment for cancer have produced success in both 34 rats and 6 cases of esophageal cancer.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77045660","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 : 1995-09-20DOI: 10.1109/IEMBS.1995.579676
F. Abuzzahab, G. Harris, S. Kidder, J. Johnson
A four-segment rigid body model of the foot and ankle has been previously developed by the authors' group which is capable of describing gait kinematics (S.M. Kidder et al., Proc. IEEE EMBS, San Diego, CA, USA, 15(3), p. 1065-6, 1993). A kinetic model for use with that system is described in this study. The kinetic model allows independent foot articulations at the first metatarsophalangeal, talo-navicular, subtalar and talocrural joints. Forces and moments resulting at these joints during the stance phase of gait are described.
先前，作者团队开发了一个足部和踝关节的四段刚体模型，能够描述步态运动学(S.M. Kidder等人，Proc. IEEE EMBS, San Diego, CA, USA, 15(3)， p. 1065-6, 1993)。本研究描述了用于该系统的动力学模型。动力学模型允许独立的足关节在第一跖趾、距舟关节、距下关节和距踝关节。力和力矩产生在这些关节在步态的立场阶段进行了描述。
{"title":"Analysis of foot and ankle kinetics during gait","authors":"F. Abuzzahab, G. Harris, S. Kidder, J. Johnson","doi":"10.1109/IEMBS.1995.579676","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579676","url":null,"abstract":"A four-segment rigid body model of the foot and ankle has been previously developed by the authors' group which is capable of describing gait kinematics (S.M. Kidder et al., Proc. IEEE EMBS, San Diego, CA, USA, 15(3), p. 1065-6, 1993). A kinetic model for use with that system is described in this study. The kinetic model allows independent foot articulations at the first metatarsophalangeal, talo-navicular, subtalar and talocrural joints. Forces and moments resulting at these joints during the stance phase of gait are described.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77150242","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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