Pub Date : 1994-11-03DOI: 10.1109/IEMBS.1994.415435
M. Ursino, C. Cristalli
The biomechanical factors which may affect the accuracy of non-invasive blood pressure measurement with the oscillometric technique are analyzed with a parameter mathematical model. The model includes compliance of the occluding cuff, pressure transmission from the cuff to the brachial artery through arm soft tissue, and blood volume changes occurring in the collapsing brachial artery under the external load. Simulation results, concerning blood volume changes under the cuff and cuff pressure pulsations, turn out in good qualitative agreement with those reported in the recent literature. Finally, the effect of alterations in some biomechanical parameters of clinical relevance (such as arterial wall rigidity and tissue compliance) on results of the oscillometric technique are evaluated with the model. A phenomenon of pseudo-hypertension is observed when brachial artery becomes excessively rigid, as in old-aged patients.
{"title":"Mathematical analysis of the oscillometric technique for indirect blood pressure evaluation","authors":"M. Ursino, C. Cristalli","doi":"10.1109/IEMBS.1994.415435","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415435","url":null,"abstract":"The biomechanical factors which may affect the accuracy of non-invasive blood pressure measurement with the oscillometric technique are analyzed with a parameter mathematical model. The model includes compliance of the occluding cuff, pressure transmission from the cuff to the brachial artery through arm soft tissue, and blood volume changes occurring in the collapsing brachial artery under the external load. Simulation results, concerning blood volume changes under the cuff and cuff pressure pulsations, turn out in good qualitative agreement with those reported in the recent literature. Finally, the effect of alterations in some biomechanical parameters of clinical relevance (such as arterial wall rigidity and tissue compliance) on results of the oscillometric technique are evaluated with the model. A phenomenon of pseudo-hypertension is observed when brachial artery becomes excessively rigid, as in old-aged patients.","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"60 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":"116158258","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.1994.415235
Chang-Tar Tsai, Hsiao-Lung Chan, C. Tseng, Chien-Ping Wu
A new approach for an active comb filter design is proposed to remove the difficult harmonic interference contaminating the biomedical signals. The filter consists of four narrow-band bandpass filters. The center frequency of each bandpass filters is just the unwanted frequency characterized by the harmonic interference. The circuit demonstrates the capability to eliminate the interference of 60, 180, 300, and 420 Hz. The general 741 type operational amplifier has been used to realize the circuit presented. Triangular wave testing shows the effectiveness of harmonic interference cancellation.<>
{"title":"Harmonic interference elimination by an active comb filter [ECG application]","authors":"Chang-Tar Tsai, Hsiao-Lung Chan, C. Tseng, Chien-Ping Wu","doi":"10.1109/IEMBS.1994.415235","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415235","url":null,"abstract":"A new approach for an active comb filter design is proposed to remove the difficult harmonic interference contaminating the biomedical signals. The filter consists of four narrow-band bandpass filters. The center frequency of each bandpass filters is just the unwanted frequency characterized by the harmonic interference. The circuit demonstrates the capability to eliminate the interference of 60, 180, 300, and 420 Hz. The general 741 type operational amplifier has been used to realize the circuit presented. Triangular wave testing shows the effectiveness of harmonic interference cancellation.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"42 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":"121514352","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.1994.411805
K. Ueno, K. Iramina, S. Ueno
Here, the authors investigate a source model which is used in inverse problems of magnetoencephalography (MEG) or electroencephalography (EEG). A source model with a 2-dimensional spread which corresponds to the surface of the cortex is proposed. The spread of the source is expressed by locating many dipoles in a region. Assuming that the dipoles each have a time-varying moment, spatio-temporal patterns of magnetoencephalograms (MEGs) are simulated. The results show that the waveforms of MEG are affected significantly by varying the spread of the source.<>
{"title":"A source model with 2-dimensional spread of electrical activity in the human brain","authors":"K. Ueno, K. Iramina, S. Ueno","doi":"10.1109/IEMBS.1994.411805","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411805","url":null,"abstract":"Here, the authors investigate a source model which is used in inverse problems of magnetoencephalography (MEG) or electroencephalography (EEG). A source model with a 2-dimensional spread which corresponds to the surface of the cortex is proposed. The spread of the source is expressed by locating many dipoles in a region. Assuming that the dipoles each have a time-varying moment, spatio-temporal patterns of magnetoencephalograms (MEGs) are simulated. The results show that the waveforms of MEG are affected significantly by varying the spread of the source.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114782790","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.1994.412011
T. Yamamoto, H. Takano
In a clinical use of functional electrical stimulation (FES), for example, it is often difficult to directly estimate muscular strength of the stimulated muscle. In this study, muscle sound has been applied for estimating muscle tonus, muscle strength, and tolerance for muscle fatigue. The relation between muscle sound and inner pressure of fascia, in addition to EMG and joint torque, has been examined. Based on autoregressive model analysis, the amplitude and peak frequency of the power-spectrum of muscle sound shows a better correlation to represent change of muscle strength in fatigued conditions, etc. It is concluded that muscle sound is an useful parameter to estimate muscle tonus, in addition to the popular electrophysiological signal EMG.<>
{"title":"Application of muscle sound to assess muscle tonus of the electrically stimulated muscle for FES","authors":"T. Yamamoto, H. Takano","doi":"10.1109/IEMBS.1994.412011","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.412011","url":null,"abstract":"In a clinical use of functional electrical stimulation (FES), for example, it is often difficult to directly estimate muscular strength of the stimulated muscle. In this study, muscle sound has been applied for estimating muscle tonus, muscle strength, and tolerance for muscle fatigue. The relation between muscle sound and inner pressure of fascia, in addition to EMG and joint torque, has been examined. Based on autoregressive model analysis, the amplitude and peak frequency of the power-spectrum of muscle sound shows a better correlation to represent change of muscle strength in fatigued conditions, etc. It is concluded that muscle sound is an useful parameter to estimate muscle tonus, in addition to the popular electrophysiological signal EMG.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"72 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":"126445383","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.1994.411916
W. Ruan, R. Guardo, A. Adler, G. Savoie
A 2-D finite element model of solving the forward problem for induced current impedance imaging is described. The improved Newton-Raphson method is used as the image reconstruction algorithm. Dynamic images obtained by the current induction method are presented. It is found that the improved Newton-Raphson method can stabilize the ill-posed inverse problem in EIT.<>
{"title":"Finite element modeling of impedance imaging using induced currents","authors":"W. Ruan, R. Guardo, A. Adler, G. Savoie","doi":"10.1109/IEMBS.1994.411916","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411916","url":null,"abstract":"A 2-D finite element model of solving the forward problem for induced current impedance imaging is described. The improved Newton-Raphson method is used as the image reconstruction algorithm. Dynamic images obtained by the current induction method are presented. It is found that the improved Newton-Raphson method can stabilize the ill-posed inverse problem in EIT.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"9 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":"126554479","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.1994.411946
P. Lum, S. Lehman, D. Reinkensmeyer
Specially designed machines, which the authors call rehabilitators, could automate some of the repetitive aspects of physical and occupational therapy. The authors envision developing a family of inexpensive machines, each designed to retrain coordination in a specific activity of daily living, that could be used by physical and occupational therapists. To this end, the authors have built a rehabilitator for adaptively assisting hemiplegic stroke patients in bimanual lifting. The rehabilitator, operating under a simple control law, can adapt properly to two extremes of patient ability: no ability to apply force to an object with the disabled hand, and full ability to lift an object bimanually.<>
{"title":"An adaptive therapy machine for rehabilitating bimanual lifting in hemiplegic stroke patients","authors":"P. Lum, S. Lehman, D. Reinkensmeyer","doi":"10.1109/IEMBS.1994.411946","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.411946","url":null,"abstract":"Specially designed machines, which the authors call rehabilitators, could automate some of the repetitive aspects of physical and occupational therapy. The authors envision developing a family of inexpensive machines, each designed to retrain coordination in a specific activity of daily living, that could be used by physical and occupational therapists. To this end, the authors have built a rehabilitator for adaptively assisting hemiplegic stroke patients in bimanual lifting. The rehabilitator, operating under a simple control law, can adapt properly to two extremes of patient ability: no ability to apply force to an object with the disabled hand, and full ability to lift an object bimanually.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"66 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":"121920840","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.1994.415242
Ying-Chang Chen, Jyh-Horng Chen
Presents an analog CMOS circuit simulation of a model for the sensory transduction in the mammalian cochlea. This model consists of basilar membrane, inner hair cell and spiral ganglion of the auditory nerve system. It employs subthreshold CMOS technology and an analog circuit which results in a real time, micropower device. The results of its response to sinusoidal excitation simulation are shown.<>
{"title":"An analog CMOS circuit for cochlea implant","authors":"Ying-Chang Chen, Jyh-Horng Chen","doi":"10.1109/IEMBS.1994.415242","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415242","url":null,"abstract":"Presents an analog CMOS circuit simulation of a model for the sensory transduction in the mammalian cochlea. This model consists of basilar membrane, inner hair cell and spiral ganglion of the auditory nerve system. It employs subthreshold CMOS technology and an analog circuit which results in a real time, micropower device. The results of its response to sinusoidal excitation simulation are shown.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"42 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":"121774271","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.1994.415223
K. Kaczmarek, M. Tyler, P. Bach-y-Rita
Electrical stimulation of the sense of touch may be used to display pictorial information to blind computer users via a fingertip-scanned (haptic) touch tablet containing embedded electrodes. This might be particularly useful to users of systems with graphical user interfaces, or with drawing and layout software. Electrotactile (electrocutaneous) stimulation on the fingertip, however, differs substantially from that on other body locations. We discuss the implications of designing a practical graphics haptic display by addressing the high-resistance and variable nature of the fingertip electrode-skin interface.<>
{"title":"Electrotactile haptic display on the fingertips: preliminary results","authors":"K. Kaczmarek, M. Tyler, P. Bach-y-Rita","doi":"10.1109/IEMBS.1994.415223","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415223","url":null,"abstract":"Electrical stimulation of the sense of touch may be used to display pictorial information to blind computer users via a fingertip-scanned (haptic) touch tablet containing embedded electrodes. This might be particularly useful to users of systems with graphical user interfaces, or with drawing and layout software. Electrotactile (electrocutaneous) stimulation on the fingertip, however, differs substantially from that on other body locations. We discuss the implications of designing a practical graphics haptic display by addressing the high-resistance and variable nature of the fingertip electrode-skin interface.<<ETX>>","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"90 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":"115865424","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.1994.415360
S. Field, G. Drzewiecki
Previous studies of vascular segments treated the vascular wall as a rigid or deformable structure with linear elasticity. The present study relieves this assumption, with the goal of modeling a vascular segment more completely. Because the vascular segment is deformable the three dynamic elements are lumen area dependent, i.e. the fluid resistance, inertance, and compliance are all functions of the lumen area and are thus also nonlinear. Due to the nonlinearities inherent in the vascular segment complex dynamic phenomenon, such as chaos, were investigated. Two lumped parameter three element nonlinear models were developed. A mathematical model was formulated from a system of nonlinear ordinary differential equations. These equations were numerically solved on a computer through a two element fourth order Runge-Kutta algorithm. An in vitro model was also employed, using a segment of latex tubing as a model for the collapsible vascular segment. Both models were investigated by applying a sinusoidal input pressure with a variable amplitude, offset, and frequency. Complex dynamic behavior was observed in both models for several parameter sets. In addition, the frequency response for the system was found to be dependent on transmural pressure and often demonstrated the presence of multiple resonances unlike a linear vessel model. Finally, these models can be applied to modeling flexible dynamic stenosis.
{"title":"Nonlinear dynamic behavior and driven chaos from in vitro and computer models of a collapsible vascular segment","authors":"S. Field, G. Drzewiecki","doi":"10.1109/IEMBS.1994.415360","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415360","url":null,"abstract":"Previous studies of vascular segments treated the vascular wall as a rigid or deformable structure with linear elasticity. The present study relieves this assumption, with the goal of modeling a vascular segment more completely. Because the vascular segment is deformable the three dynamic elements are lumen area dependent, i.e. the fluid resistance, inertance, and compliance are all functions of the lumen area and are thus also nonlinear. Due to the nonlinearities inherent in the vascular segment complex dynamic phenomenon, such as chaos, were investigated. Two lumped parameter three element nonlinear models were developed. A mathematical model was formulated from a system of nonlinear ordinary differential equations. These equations were numerically solved on a computer through a two element fourth order Runge-Kutta algorithm. An in vitro model was also employed, using a segment of latex tubing as a model for the collapsible vascular segment. Both models were investigated by applying a sinusoidal input pressure with a variable amplitude, offset, and frequency. Complex dynamic behavior was observed in both models for several parameter sets. In addition, the frequency response for the system was found to be dependent on transmural pressure and often demonstrated the presence of multiple resonances unlike a linear vessel model. Finally, these models can be applied to modeling flexible dynamic stenosis.","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":"130113236","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.1994.415388
Zhenyao Xu, R. Gulrajani, M. Lorange, P. Savard
The simulation of ventricular ectopic beats with a three-dimensional computer heart model incorporating anisotropic propagation is discussed here. The simulated body surface potential maps corresponding to different ectopic sites are in good agreement with clinically described results. The long-term goal is to catalogue surface maps and their corresponding ectopic sites so as to help identify sites of origin of ventricular tachycardia.
{"title":"Simulation of ventricular ectopic beats with a computer heart model","authors":"Zhenyao Xu, R. Gulrajani, M. Lorange, P. Savard","doi":"10.1109/IEMBS.1994.415388","DOIUrl":"https://doi.org/10.1109/IEMBS.1994.415388","url":null,"abstract":"The simulation of ventricular ectopic beats with a three-dimensional computer heart model incorporating anisotropic propagation is discussed here. The simulated body surface potential maps corresponding to different ectopic sites are in good agreement with clinically described results. The long-term goal is to catalogue surface maps and their corresponding ectopic sites so as to help identify sites of origin of ventricular tachycardia.","PeriodicalId":344622,"journal":{"name":"Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"40 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":"130263064","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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