Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166819
M. Nalbach, O. Skipa, F. Sachse, O. Dossel
Noninvasive Imaging of the bioelectric processes on the heart using Electrocardiography (ECG) and Magnetocardiography (MCG) data is a widely discussed research topic of the recent years. The source space of ECG is compared with the source space of MCG and vice versa to investigate the difference of information content of these mapping techniques for source imaging purposes. The approach allows the calculation of the intersection and non-intersection part (the calculation of silent sources) of MCG (ECG) in comparison to ECG (MCG). The investigation was carried out on a Finite Element model which was constructed from a magnetic resonance imaging (MRI) dataset of a volunteer. Anisotropic fibre orientation was applied to myocardium to investigate its effect on the differences of the source spaces.
{"title":"Investigation of the source space of electrocardiography and magnetocardiography using isotropic and anisotropic thorax models","authors":"M. Nalbach, O. Skipa, F. Sachse, O. Dossel","doi":"10.1109/CIC.2002.1166819","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166819","url":null,"abstract":"Noninvasive Imaging of the bioelectric processes on the heart using Electrocardiography (ECG) and Magnetocardiography (MCG) data is a widely discussed research topic of the recent years. The source space of ECG is compared with the source space of MCG and vice versa to investigate the difference of information content of these mapping techniques for source imaging purposes. The approach allows the calculation of the intersection and non-intersection part (the calculation of silent sources) of MCG (ECG) in comparison to ECG (MCG). The investigation was carried out on a Finite Element model which was constructed from a magnetic resonance imaging (MRI) dataset of a volunteer. Anisotropic fibre orientation was applied to myocardium to investigate its effect on the differences of the source spaces.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"27 1","pages":"501-504"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166819","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62181520","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166823
K. Matthys, D. Vanhercke, S. Van Aken, K. De Groote, I. Coomans, P. Verdonck
Aiming to improve early diagnosis of people at cardiovascular risk, we are developing a custom set-up to allow an adequate hemodynamic analysis of heart function and arterial circulation properties, based on non-invasive acquisition of pressure (arterial tonometry) and flow (Doppler ultrasound techniques) waveforms. In an experimental setting 15 healthy volunteers were examined on a custom made supine bicycle. Able to record usable data throughout the bicycle test and automatically analyse derived hemodynamic parameters such as compliance, peripheral resistance, etc., we also applied the set-up in a real clinical environment. This research contributes to a more complete cardiovascular examination without significant additional discomfort for the patient or prolongation of the test protocol.
{"title":"Non-invasive assessment of hemodynamics in adolescents with arterial tonometry and Doppler ultrasound during a conventional stress test","authors":"K. Matthys, D. Vanhercke, S. Van Aken, K. De Groote, I. Coomans, P. Verdonck","doi":"10.1109/CIC.2002.1166823","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166823","url":null,"abstract":"Aiming to improve early diagnosis of people at cardiovascular risk, we are developing a custom set-up to allow an adequate hemodynamic analysis of heart function and arterial circulation properties, based on non-invasive acquisition of pressure (arterial tonometry) and flow (Doppler ultrasound techniques) waveforms. In an experimental setting 15 healthy volunteers were examined on a custom made supine bicycle. Able to record usable data throughout the bicycle test and automatically analyse derived hemodynamic parameters such as compliance, peripheral resistance, etc., we also applied the set-up in a real clinical environment. This research contributes to a more complete cardiovascular examination without significant additional discomfort for the patient or prolongation of the test protocol.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"517-520"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166823","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62181648","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166844
F. Hanser, B. Tilg, R. Modre, G. Fischer, B. Messnarz, F. Hintringer, F. Roithinger
The feasibility of atrial activation time imaging is investigated based on data sets of four patients who underwent an electrophysiologic study. Several pacing protocols with pacing sites at the right atrial appendage, coronary sinus, and high right atrium were part of the study and were employed to reconstruct the associated atrial activation time patterns. The localization error was estimated to be between 8 and 14 mm.
{"title":"Feasibility of atrial activation time imaging","authors":"F. Hanser, B. Tilg, R. Modre, G. Fischer, B. Messnarz, F. Hintringer, F. Roithinger","doi":"10.1109/CIC.2002.1166844","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166844","url":null,"abstract":"The feasibility of atrial activation time imaging is investigated based on data sets of four patients who underwent an electrophysiologic study. Several pacing protocols with pacing sites at the right atrial appendage, coronary sinus, and high right atrium were part of the study and were employed to reconstruct the associated atrial activation time patterns. The localization error was estimated to be between 8 and 14 mm.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"601-604"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166844","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62181966","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166707
G. Nollo, L. Widesott, L. Faes, A. Porta, R. Antolini
The phase spectra obtained by the classical closed loop autoregressive model (2AR) and by an open loop autoregressive model (ARXAR) were compared to shed light on the need of introducing causality in the assessment of the delay between RR and arterial pressure oscillations. The reliability of the two approaches was tested in simulation and real data setting. In simulation, the coupling strength of a bivariate closed loop process was adjusted to obtain a range of working conditions from open to closed loop. In open loop condition, 2AR and ARXAR phases were comparable and in agreement with the imposed delay. In closed loop condition, ARXAR model returned the imposed delays, while 2AR showed an intermediate value of delay. Real data were chosen to represent comparable physiological condition. The use of cross spectrum for calculating the delay from arterial pressure to RR oscillations seems adequate only in particular condition of open-loop relationship as it happens during head up tilt in young healthy subjects.
{"title":"Need of causal analysis for assessing phase relationships in closed loop interacting cardiovascular variability series","authors":"G. Nollo, L. Widesott, L. Faes, A. Porta, R. Antolini","doi":"10.1109/CIC.2002.1166707","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166707","url":null,"abstract":"The phase spectra obtained by the classical closed loop autoregressive model (2AR) and by an open loop autoregressive model (ARXAR) were compared to shed light on the need of introducing causality in the assessment of the delay between RR and arterial pressure oscillations. The reliability of the two approaches was tested in simulation and real data setting. In simulation, the coupling strength of a bivariate closed loop process was adjusted to obtain a range of working conditions from open to closed loop. In open loop condition, 2AR and ARXAR phases were comparable and in agreement with the imposed delay. In closed loop condition, ARXAR model returned the imposed delays, while 2AR showed an intermediate value of delay. Real data were chosen to represent comparable physiological condition. The use of cross spectrum for calculating the delay from arterial pressure to RR oscillations seems adequate only in particular condition of open-loop relationship as it happens during head up tilt in young healthy subjects.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"61-64"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166707","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62179343","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166701
L. Senhadji, Feng Wang, Alfredo I. Hernández, Guy Carrault
P wave detection requires a robust QRS-T cancellation method. Interesting algorithms have been proposed for beat-to-beat QRS-T cancellation. Previous studies have shown that adaptive methods lead to good cancellation of the QRS-T interval which generally guarantees the performance of P wave detection. However, adaptive methods suffer from the nonstationary behavior of ECG signals and particularly beat-to-beat morphology changes of the QRS. We present a new approach for two ECG channel QRS-T cancellation based on the dyadic wavelet transform. The method is insensitive to QRS morphology changes and performs well in the presence of ectopic beats, transient artifacts, baseline drifts and isolated P waves. Our approach allows the P wave to be enhanced better than methods recently proposed.
{"title":"Wavelets extrema representation for QRS-T cancellation and P wave detection","authors":"L. Senhadji, Feng Wang, Alfredo I. Hernández, Guy Carrault","doi":"10.1109/CIC.2002.1166701","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166701","url":null,"abstract":"P wave detection requires a robust QRS-T cancellation method. Interesting algorithms have been proposed for beat-to-beat QRS-T cancellation. Previous studies have shown that adaptive methods lead to good cancellation of the QRS-T interval which generally guarantees the performance of P wave detection. However, adaptive methods suffer from the nonstationary behavior of ECG signals and particularly beat-to-beat morphology changes of the QRS. We present a new approach for two ECG channel QRS-T cancellation based on the dyadic wavelet transform. The method is insensitive to QRS morphology changes and performs well in the presence of ectopic beats, transient artifacts, baseline drifts and isolated P waves. Our approach allows the P wave to be enhanced better than methods recently proposed.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"37-40"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166701","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62179626","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166721
M.L. Brown, J. Christensen, J. Gillberg
The PR Logic dual-chamber defection algorithm discriminates VT/VF from SVT using hierarchical rules based on the pattern and timing of AA, VV, AV, and VA intervals. It cannot always discriminate rapidly-conducted atrial fibrillation(AF) from double tachycardia. Coexisting AF and VT/VF, or SVT with 1:1 antegrade conduction from VT with 1:1 retrograde conduction. This study evaluated a new tachyarrhythmia detection algorithm that supplements analysis of dual-chamber intervals with analysis of ventricular electrogram morphology based on the Wavelet Dynamic Discrimination Algorithm. Combined analysis of dual-chamber intervals and ventricular electrogram morphology reduced inappropriate detection of SVTs by 79% compared to dual chamber intervals alone without compromising sensitivity for detection of VT/VF.
{"title":"Improved discrimination of VT from SVT in dual-chamber ICDs by combined analysis of dual-chamber intervals and ventricular electrogram morphology","authors":"M.L. Brown, J. Christensen, J. Gillberg","doi":"10.1109/CIC.2002.1166721","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166721","url":null,"abstract":"The PR Logic dual-chamber defection algorithm discriminates VT/VF from SVT using hierarchical rules based on the pattern and timing of AA, VV, AV, and VA intervals. It cannot always discriminate rapidly-conducted atrial fibrillation(AF) from double tachycardia. Coexisting AF and VT/VF, or SVT with 1:1 antegrade conduction from VT with 1:1 retrograde conduction. This study evaluated a new tachyarrhythmia detection algorithm that supplements analysis of dual-chamber intervals with analysis of ventricular electrogram morphology based on the Wavelet Dynamic Discrimination Algorithm. Combined analysis of dual-chamber intervals and ventricular electrogram morphology reduced inappropriate detection of SVTs by 79% compared to dual chamber intervals alone without compromising sensitivity for detection of VT/VF.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"117-120"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166721","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62179993","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166766
H. Park, W. Groh, W. Combs, E. Berbari
This study presents several new approaches to analyze the non-invasively recorded His-Purkinje system (HPS) signals from patients with myotonic muscular dystrophy. A high resolution electrocardiogram based on signal averaging to improve the signal-to-noise ratio(SNR) is a well established means to record HPS potentials. These new approaches used methods to temporally and spectrally separate the HPS potentials from the P wave potentials. These included both physiologically based and signal processing based schemes. Separating or shifting the P wave from the HPS potentials using heart rate dependent averaging and the addition of several highpass filtering methods proved somewhat, but not totally successful. In the group of patients with sequential recordings over a period of two years the progression of their muscular dystrophy may also be seen in the heart as well. This may then produce noticeable progressive trends or changes in their HPS waveforms over time. The most noticeable changes found in this study were temporal changes and morphological changes of the HPS activity of these patients over time.
{"title":"Analysis of non-invasively recorded His-Purkinje signals from patients with myotonic muscular dystrophy","authors":"H. Park, W. Groh, W. Combs, E. Berbari","doi":"10.1109/CIC.2002.1166766","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166766","url":null,"abstract":"This study presents several new approaches to analyze the non-invasively recorded His-Purkinje system (HPS) signals from patients with myotonic muscular dystrophy. A high resolution electrocardiogram based on signal averaging to improve the signal-to-noise ratio(SNR) is a well established means to record HPS potentials. These new approaches used methods to temporally and spectrally separate the HPS potentials from the P wave potentials. These included both physiologically based and signal processing based schemes. Separating or shifting the P wave from the HPS potentials using heart rate dependent averaging and the addition of several highpass filtering methods proved somewhat, but not totally successful. In the group of patients with sequential recordings over a period of two years the progression of their muscular dystrophy may also be seen in the heart as well. This may then produce noticeable progressive trends or changes in their HPS waveforms over time. The most noticeable changes found in this study were temporal changes and morphological changes of the HPS activity of these patients over time.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"293-296"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166766","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62180514","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166767
H. Kestler, A. Muller, V. Hombach, J. Wohrle, O. Grebe, G. Palm, M. Moher, F. Schwenker
Two types of measurements are usually performed from high resolution ECG recordings: (a) static parameters derived from the signal-averaged QRS complex and (b) variant markers derived from beat-to-beat recordings. It is known that an increased QRS micro-variability and ventricular late potentials are associated with an increased risk for malignant arrhythmias. However, the diagnostic power of the singular parameters is limited In this study we investigated the diagnostic ability of a decision fusion of both variant and static high-resolution ECG parameters with radial-basis-function (RBF) networks. Continuous and signal-averaged ECGs were recorded from 51 healthy volunteers without any structural heart disease and no cardiac risk factors and from 44 patients with coronary heart disease and ventricular arrhythmias. Beat-to-beat micro-variability measurement of the QRS complex and the ST-T segment was based on 250 consecutive sinus beats per individual. Signal-averaged ECGs were analyzed with the Simson method (QRSD, RMS, LAS). Two RBF networks were trained One on the three signal averaged parameters and one with the 141D variability vector The two soft decisions from each RBF network were then combined by average fusion and maximum detection into a final crisp decision which resulted in an unusually high discriminative accuracy.
{"title":"Decision fusion of micro-variability and signal averaged ECG parameters from the QRS complex with RBF networks","authors":"H. Kestler, A. Muller, V. Hombach, J. Wohrle, O. Grebe, G. Palm, M. Moher, F. Schwenker","doi":"10.1109/CIC.2002.1166767","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166767","url":null,"abstract":"Two types of measurements are usually performed from high resolution ECG recordings: (a) static parameters derived from the signal-averaged QRS complex and (b) variant markers derived from beat-to-beat recordings. It is known that an increased QRS micro-variability and ventricular late potentials are associated with an increased risk for malignant arrhythmias. However, the diagnostic power of the singular parameters is limited In this study we investigated the diagnostic ability of a decision fusion of both variant and static high-resolution ECG parameters with radial-basis-function (RBF) networks. Continuous and signal-averaged ECGs were recorded from 51 healthy volunteers without any structural heart disease and no cardiac risk factors and from 44 patients with coronary heart disease and ventricular arrhythmias. Beat-to-beat micro-variability measurement of the QRS complex and the ST-T segment was based on 250 consecutive sinus beats per individual. Signal-averaged ECGs were analyzed with the Simson method (QRSD, RMS, LAS). Two RBF networks were trained One on the three signal averaged parameters and one with the 141D variability vector The two soft decisions from each RBF network were then combined by average fusion and maximum detection into a final crisp decision which resulted in an unusually high discriminative accuracy.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"297-300"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166767","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62180568","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166742
J. Moraes, M.O. Seixas, F.N. Vilani, E.V. Costa
An unsupervised method to recognize and classify QRS complexes was developed in order to create an automatic cardiac beat classifier in real time. After exhaustive analysis, four features extracted from the QRS complex in the time domain were selected as the ones presenting the best results: width, total sum of the areas under the positive and negative curves, total sum of the absolute values of sample variations and total amplitude. Preliminary studies indicated these features follow a normal distribution, allowing the use of the Mahalanobis distance as their classification criterion. After an initial learning period, the algorithm extracts the four features from every new QRS complex and calculates the Mahalanobis distance between its feature set and the centroids of all existing classes to determine the class in which the new QRS belongs to. If a predefined distance is surpassed, a new class is created Using 44 records from the MIT-BIH we have obtained 90,74% of sensitivity, 96,55% of positive predictivity and 0.242% of false positives.
{"title":"A real time QRS complex classification method using Mahalanobis distance","authors":"J. Moraes, M.O. Seixas, F.N. Vilani, E.V. Costa","doi":"10.1109/CIC.2002.1166742","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166742","url":null,"abstract":"An unsupervised method to recognize and classify QRS complexes was developed in order to create an automatic cardiac beat classifier in real time. After exhaustive analysis, four features extracted from the QRS complex in the time domain were selected as the ones presenting the best results: width, total sum of the areas under the positive and negative curves, total sum of the absolute values of sample variations and total amplitude. Preliminary studies indicated these features follow a normal distribution, allowing the use of the Mahalanobis distance as their classification criterion. After an initial learning period, the algorithm extracts the four features from every new QRS complex and calculates the Mahalanobis distance between its feature set and the centroids of all existing classes to determine the class in which the new QRS belongs to. If a predefined distance is surpassed, a new class is created Using 44 records from the MIT-BIH we have obtained 90,74% of sensitivity, 96,55% of positive predictivity and 0.242% of false positives.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"201-204"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166742","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62180684","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 : 2002-09-22DOI: 10.1109/CIC.2002.1166756
O. Aslanidi, O. Mornev, A. Holden
Mechanisms for termination of re-entry and defibrillation still remain a challenge. Using the Luo-Rudy family of virtual ventricular tissues we simulate termination of re-entrant spiral waves with a periodic low-voltage shock studying a new mechanism for defibrillation. Essential for the simulations is extension of the bidomain tissue representation in order to account for the existence of an external bath ("tridomain"), where the shock is applied The bidomain model with the bath reproduces periodic patterns of depolarization in the virtual tissue - standing waves, previously observed in experiments. In contrast to the classical exponential decay of voltage near the electrodes, standing waves entrain the whole tissue, thus canceling the spiral waves. The mechanism of this far-field effect is based on redistribution of the externally applied current by the conductive bath.
{"title":"Low-voltage defibrillation in bidomain virtual ventricular tissue: effect of the bath","authors":"O. Aslanidi, O. Mornev, A. Holden","doi":"10.1109/CIC.2002.1166756","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166756","url":null,"abstract":"Mechanisms for termination of re-entry and defibrillation still remain a challenge. Using the Luo-Rudy family of virtual ventricular tissues we simulate termination of re-entrant spiral waves with a periodic low-voltage shock studying a new mechanism for defibrillation. Essential for the simulations is extension of the bidomain tissue representation in order to account for the existence of an external bath (\"tridomain\"), where the shock is applied The bidomain model with the bath reproduces periodic patterns of depolarization in the virtual tissue - standing waves, previously observed in experiments. In contrast to the classical exponential decay of voltage near the electrodes, standing waves entrain the whole tissue, thus canceling the spiral waves. The mechanism of this far-field effect is based on redistribution of the externally applied current by the conductive bath.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"255-258"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166756","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62180711","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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