Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.575084
L. Titomir, V. Trunov, I. P. Poljakova
An improvement of the electrocardiographic body surface potential mapping technique is proposed to provide more explicit recognition of excitation processes in the heart by means of calculation of the potential distribution on the spherical quasiepicardium and separation of its extremum regions. The method is illustrated with cases of ventricular extrasystole and preexcitation syndrome.
{"title":"Pictorial representation of local events in the heart on the basis of noninvasive spherical-quasiepicardium potential mapping","authors":"L. Titomir, V. Trunov, I. P. Poljakova","doi":"10.1109/IEMBS.1995.575084","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575084","url":null,"abstract":"An improvement of the electrocardiographic body surface potential mapping technique is proposed to provide more explicit recognition of excitation processes in the heart by means of calculation of the potential distribution on the spherical quasiepicardium and separation of its extremum regions. The method is illustrated with cases of ventricular extrasystole and preexcitation syndrome.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"280 ","pages":"229-230 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91551709","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.1995.579837
F. Germagnoli, S. Lazzari, R. Lombardi, G. Magenes
A new artificial tactile sensor has been developed to provide reliable data about the exploration of small geometrical details of an object (fine-form discrimination). The main characteristics of this sensor are: high spatial resolution, small packaging and flexibility of the support which implies the chance of wearing it as a finger of a glove. This sensor will be applied in both robotic and rehabilitation fields.
{"title":"An artificial tactile sensor for fine-form discrimination","authors":"F. Germagnoli, S. Lazzari, R. Lombardi, G. Magenes","doi":"10.1109/IEMBS.1995.579837","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579837","url":null,"abstract":"A new artificial tactile sensor has been developed to provide reliable data about the exploration of small geometrical details of an object (fine-form discrimination). The main characteristics of this sensor are: high spatial resolution, small packaging and flexibility of the support which implies the chance of wearing it as a finger of a glove. This sensor will be applied in both robotic and rehabilitation fields.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"65 1","pages":"1577-1578 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90172609","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.1995.579753
S. Kukreja, B. Haverkamp, D. Westwick, R. Kearney, H. Galiana, M. Verhaegen
Presents results a new algorithm for modeling biological systems using a state space approach. One of the MIMO Output-Error State Space identification (MOESP) family of algorithms (see M. Verhaegen and P. Dewilde, Int. J. Control, vol. 55, no. 5, p. 1187-1210, 1992) has been adapted to model the linear part of human ankle mechanics. A mixed causal/anti-causal state space model was calculated to examine the relationship between torque and position of the ankle. Simulated and real data are used to show that the method yields parametric models for ankle mechanics that describe behavior as well as nonparametric models. However, the parametric models obtained using the MOESP identification method have many fewer parameters.
给出了一种用状态空间方法对生物系统建模的新算法。MIMO输出错误状态空间识别(MOESP)系列算法之一(见M. Verhaegen和P. Dewilde, Int.)。《控制》,第55卷,第55期。5, p. 1187-1210, 1992)已被用于模拟人类踝关节力学的线性部分。计算了一个混合因果/反因果状态空间模型来检验扭矩与踝关节位置之间的关系。仿真数据和实际数据表明,该方法可以得到描述踝关节行为的参数模型和非参数模型。然而,采用MOESP识别方法得到的参数模型参数较少。
{"title":"Subspace identification method for ankle mechanics","authors":"S. Kukreja, B. Haverkamp, D. Westwick, R. Kearney, H. Galiana, M. Verhaegen","doi":"10.1109/IEMBS.1995.579753","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579753","url":null,"abstract":"Presents results a new algorithm for modeling biological systems using a state space approach. One of the MIMO Output-Error State Space identification (MOESP) family of algorithms (see M. Verhaegen and P. Dewilde, Int. J. Control, vol. 55, no. 5, p. 1187-1210, 1992) has been adapted to model the linear part of human ankle mechanics. A mixed causal/anti-causal state space model was calculated to examine the relationship between torque and position of the ankle. Simulated and real data are used to show that the method yields parametric models for ankle mechanics that describe behavior as well as nonparametric models. However, the parametric models obtained using the MOESP identification method have many fewer parameters.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"1 1","pages":"1413-1414 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88922549","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.1995.579727
F. Betrini, A. Caumo, C. Cobelli
In the present study the authors evaluated the impact of different experimental protocols on glucose minimal models identification. They used a realistic comprehensive nonlinear model of the glucose-insulin system to generate unlabeled and labeled glucose data during an IVGTT and a meal-like study. Subsequently, Monte Carlo simulations were used to compare the values and precision of the estimates of the minimal models indices obtained from the two experimental protocols. The authors' results demonstrate that both the values and the precision of the minimal model parameters are influenced by the experimental protocol. In particular, they found that the minimal model parameters estimated from the meal-like study are less precise but probably more physiologically plausible than those obtained from the IVGTT. The lower precision achieved with the meal-like study protocol is probably due to both the relatively unfrequent sampling schedule and the non-optimality of the glucose and insulin profiles for minimal model analysis.
{"title":"Minimal models in meal-like protocols: simulation studies to assess precision and physiological plausibility of parameter estimates","authors":"F. Betrini, A. Caumo, C. Cobelli","doi":"10.1109/IEMBS.1995.579727","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579727","url":null,"abstract":"In the present study the authors evaluated the impact of different experimental protocols on glucose minimal models identification. They used a realistic comprehensive nonlinear model of the glucose-insulin system to generate unlabeled and labeled glucose data during an IVGTT and a meal-like study. Subsequently, Monte Carlo simulations were used to compare the values and precision of the estimates of the minimal models indices obtained from the two experimental protocols. The authors' results demonstrate that both the values and the precision of the minimal model parameters are influenced by the experimental protocol. In particular, they found that the minimal model parameters estimated from the meal-like study are less precise but probably more physiologically plausible than those obtained from the IVGTT. The lower precision achieved with the meal-like study protocol is probably due to both the relatively unfrequent sampling schedule and the non-optimality of the glucose and insulin profiles for minimal model analysis.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"17 3","pages":"1361-1362 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91437536","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.1995.579811
A.G. Miller, T. Choy, H. Chan, Y.T. Zhang
Intuition would suggest that any additional mass caused by carcinoma in the lungs should change the overall eigen system of the thorax in resonance. To confirm this the authors undertook measurements on several carcinoma patients to ascertain whether this is indeed the case. They present two cases in which one can observe this suspected behaviour without the problems of associated fluid or other conditions masking the effect one wishes to study. The authors have noted that usually only directly above the carcinoma site does any significant difference appear in the spectral response thus suggesting that carcinomas may generate an acoustical shadow. However, the authors conclude that further research is required before this can be used in any clinical sense.
{"title":"Does pulmonary carcinoma affect the resonant properties of the thorax?","authors":"A.G. Miller, T. Choy, H. Chan, Y.T. Zhang","doi":"10.1109/IEMBS.1995.579811","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579811","url":null,"abstract":"Intuition would suggest that any additional mass caused by carcinoma in the lungs should change the overall eigen system of the thorax in resonance. To confirm this the authors undertook measurements on several carcinoma patients to ascertain whether this is indeed the case. They present two cases in which one can observe this suspected behaviour without the problems of associated fluid or other conditions masking the effect one wishes to study. The authors have noted that usually only directly above the carcinoma site does any significant difference appear in the spectral response thus suggesting that carcinomas may generate an acoustical shadow. However, the authors conclude that further research is required before this can be used in any clinical sense.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"65 1","pages":"1529-1530 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79057580","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.1995.575141
G. Sierra, A. Cabrera, A. Martínez-Rubio, L. Reinhardt, T. Fetsch, S. Yli-mayry, K. Balkenhoff, G. Breithardt
A combined algorithm is proposed for the detection of ventricular fibrillation and its accurate discrimination from other rhythms. A total of 95 sinus rhythms, 15 monomorphic ventricular tachycardias, 33 atrial fibrillations, 39 supraventricular tachycardias and 30 ventricular fibrillations were analyzed. The algorithm tests three characteristics of the ventricular fibrillation through the estimation of the isoelectric potential, the power spectrum and the coherence spectrum. The algorithm allowed a reliable distinction of ventricular fibrillation from the other rhythms. The aim of this algorithm is to be used in any external device processing surface ECG signals.
{"title":"A combined method for the detection of ventricular fibrillation","authors":"G. Sierra, A. Cabrera, A. Martínez-Rubio, L. Reinhardt, T. Fetsch, S. Yli-mayry, K. Balkenhoff, G. Breithardt","doi":"10.1109/IEMBS.1995.575141","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575141","url":null,"abstract":"A combined algorithm is proposed for the detection of ventricular fibrillation and its accurate discrimination from other rhythms. A total of 95 sinus rhythms, 15 monomorphic ventricular tachycardias, 33 atrial fibrillations, 39 supraventricular tachycardias and 30 ventricular fibrillations were analyzed. The algorithm tests three characteristics of the ventricular fibrillation through the estimation of the isoelectric potential, the power spectrum and the coherence spectrum. The algorithm allowed a reliable distinction of ventricular fibrillation from the other rhythms. The aim of this algorithm is to be used in any external device processing surface ECG signals.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"3 1","pages":"343-344 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79458874","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.1995.579889
Jungkuk Kim, J.C. Lin, L. Reynolds
The characterization of microemboli located in whole blood is attempted by determining the Legendre coefficients of phase function from the scattered light distribution around the medium. In the radiative transport equation, a microembolus is represented as a secondary source and assumed to have a spherical form and the first order transport approximate solution of the equation is used to describe the scattered intensity distribution. After the scattered intensities are determined at the surfaces of the medium, the orthogonal property of Legendre polynomial is used to extract the coefficients out of the intensities. From the obtained coefficients, the size and complex index of refraction of microemboli are determined.
{"title":"Microemboli characterization by determination of Legendre coefficients of phase function","authors":"Jungkuk Kim, J.C. Lin, L. Reynolds","doi":"10.1109/IEMBS.1995.579889","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579889","url":null,"abstract":"The characterization of microemboli located in whole blood is attempted by determining the Legendre coefficients of phase function from the scattered light distribution around the medium. In the radiative transport equation, a microembolus is represented as a secondary source and assumed to have a spherical form and the first order transport approximate solution of the equation is used to describe the scattered intensity distribution. After the scattered intensities are determined at the surfaces of the medium, the orthogonal property of Legendre polynomial is used to extract the coefficients out of the intensities. From the obtained coefficients, the size and complex index of refraction of microemboli are determined.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"61 1","pages":"1681-1682 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79589067","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.1995.575371
D.B. Smith, D. Lovely
A matched filter is the optimal technique for detecting a known signal buried in additive white noise. Surface recorded somatosensory evoked potentials are corrupted with non-white noise, and so must be whitened before being passed to a matched filter. The authors evaluated the viability of selected artificial neural networks in whitening the noise of recorded evoked potentials.
{"title":"A neural network based approach to whitening biological noise for somatosensory evoked potential detection","authors":"D.B. Smith, D. Lovely","doi":"10.1109/IEMBS.1995.575371","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575371","url":null,"abstract":"A matched filter is the optimal technique for detecting a known signal buried in additive white noise. Surface recorded somatosensory evoked potentials are corrupted with non-white noise, and so must be whitened before being passed to a matched filter. The authors evaluated the viability of selected artificial neural networks in whitening the noise of recorded evoked potentials.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"38 1","pages":"803-804 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83229960","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.1995.579760
D. R. Carta
A model describing relations and interactions between local vessel resistances and tissue temperatures during extra-corporeal circulation (ECC) is described and developed from first principles. Unknown model parameters are estimated by means of an extended Kalman Filter from real patient data. Estimated model parameters produced good model performance in tracking patient data and produced meaningful physiological results. This approach is a necessary first step in modeling further physiological interactions in the body during hypothermic ECC.
{"title":"Parameter estimation of a physiological model for heat exchange during cardio-pulmonary bypass","authors":"D. R. Carta","doi":"10.1109/IEMBS.1995.579760","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579760","url":null,"abstract":"A model describing relations and interactions between local vessel resistances and tissue temperatures during extra-corporeal circulation (ECC) is described and developed from first principles. Unknown model parameters are estimated by means of an extended Kalman Filter from real patient data. Estimated model parameters produced good model performance in tracking patient data and produced meaningful physiological results. This approach is a necessary first step in modeling further physiological interactions in the body during hypothermic ECC.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"73 1","pages":"1427-1428 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83357631","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.1995.575378
Zhiyue Lin, J. Maris, L. Hermans, J. Vandewalle, J. De, Z. Chen
Our previous study showed that the possibility of using an optical three-layer feedforward neural network employing the gradient descent learning algorithm for automated assessment of normality of the electrogastrogram. However, problems with this algorithm are slow convergence rate and critical user-dependent parameters. In the present study, two conjugate gradient learning algorithms (quasi-Newton and scaled conjugate algorithm) were introduced and compared with the gradient descent learning algorithm for the classification of the normal and abnormal electrogastrogram. Three indexes, the convergence rate, complexity per iteration and parameter robustness, were used to evaluate the performance of each algorithm. The results showed that the scaled conjugate gradient algorithm performed the best, which was robust and provided a super linear convergence rate.
{"title":"Comparison of gradient descent and conjugate gradient learning algorithms for classification of electrogastrogram","authors":"Zhiyue Lin, J. Maris, L. Hermans, J. Vandewalle, J. De, Z. Chen","doi":"10.1109/IEMBS.1995.575378","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575378","url":null,"abstract":"Our previous study showed that the possibility of using an optical three-layer feedforward neural network employing the gradient descent learning algorithm for automated assessment of normality of the electrogastrogram. However, problems with this algorithm are slow convergence rate and critical user-dependent parameters. In the present study, two conjugate gradient learning algorithms (quasi-Newton and scaled conjugate algorithm) were introduced and compared with the gradient descent learning algorithm for the classification of the normal and abnormal electrogastrogram. Three indexes, the convergence rate, complexity per iteration and parameter robustness, were used to evaluate the performance of each algorithm. The results showed that the scaled conjugate gradient algorithm performed the best, which was robust and provided a super linear convergence rate.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":"65 1","pages":"817-818 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83374808","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}