Atrial and ventricular fibrillation: computational simulation of spiral waves in cardiac tissue

2009-10-25
Göktepe, Serdar
Kuhl, Ellen
This manuscript proposes a novel, efficient finite element solution technique for the computational simulation of cardiac electrophysiology. We apply a two-parameter model that is characterized through a fast action potential and a slow recovery variable. The former is introduced globally as a nodal degree of freedom, whereas the latter is treated locally as internal variable on the integration point level. This particular discretization is extremely efficient and highly modular since different cardiac cell models can be incorporated straightforwardly through only minor local modifications on the integration point level. In this manuscript, we illustrate the algorithm in terms of the Aliev-Panfilov model for cardiomyocytes. To ensure unconditional stability, a backward Euler scheme is applied to discretize the evolution equation for both the action potential and the recovery variable in time. To increase robustness and guarantee optimal quadratic convergence, we suggest an incremental iterative Newton-Raphson scheme and illustrate the consistent linearization of the weak form of the excitation problem. The proposed algorithm is illustrated by means of two- and three-dimensional examples of re-entrant spiral and scroll waves characteristic of cardiac arrhythmias in atrial and ventricular fibrillation.
Archive of Applied Mechanics

Suggestions

Computational modeling of electrocardiograms: A finite element approach toward cardiac excitation
Kotikanyadanam, Mohan; Göktepe, Serdar; Kuhl, Ellen (Wiley, 2010-05-01)
The objective of this work is the computational simulation of a patient-specific electrocardiogram (EKG) using a novel, robust, efficient, and modular finite element-based simulation tool for cardiac electrophysiology. We apply a two-variable approach in terms of a fast action potential and a slow recovery variable, whereby the latter phenomenologically summarizes the concentration of ionic currents. The underlying algorithm is based on a staggered solution scheme in which the action potential is introduced...
ANALYSIS OF MILLIMETER WAVE-GUIDES ON ANISOTROPIC SUBSTRATES USING THE 3-DIMENSIONAL TRANSMISSION-LINE MATRIX-METHOD
BULUTAY, C; PRASAD, S (1993-06-01)
Three-dimensional condensed asymmetrical node, variable grid, transmission-line matrix (TLM) method has been used in analyzing several millimeter waveguides on anisotropic substrates. The dispersion characteristics of image guides together with field and energy confinement properties at millimeter-wave frequencies have been investigated. Edge coupled microstrip line on a uniaxial substrate is analyzed for the even and odd mode dispersion characteristics. Finally the same analysis is repeated for bilateral f...
Computational modeling of electrochemical coupling: A novel finite element approach towards ionic models for cardiac electrophysiology
Wong, Jonathan; Göktepe, Serdar; Kuhl, Ellen (2011-01-01)
We propose a novel, efficient finite element solution technique to simulate the electrochemical response of excitable cardiac tissue. We apply a global-local split in which the membrane potential of the electrical problem is introduced globally as a nodal degree of freedom, while the state variables of the chemical problem are treated locally as internal variables on the integration point level. This particular discretization is efficient and highly modular since different cardiac cell models can be incorpo...
Electromagnetic interaction complexity reduction using deep learnin
Karaosmanoğlu, Barışcan; Ergül, Özgür Salih; Department of Electrical and Electronics Engineering (2019)
In this thesis, we present a novel approach to accelerate electromagnetic simulations by the multilevel fast multipole algorithm (MLFMA). The strategy is based on a progressive elimination of electromagnetic interactions, resulting in trimmed tree structures, during iterative solutions. To systematically perform such eliminations, artificial neural network (ANN) models are constructed and trained to estimate errors in updated surface current coefficients. These column eliminations are supported by straightf...
Cross-like terahertz metamaterial absorber for sensing applications
SABAH, Cumali; MULLA, Batuhan; Altan, Hakan; Ozyuzer, Lutfi (2018-08-01)
In this work, a new multiband terahertz metamaterial absorber is designed and characterised by numerical simulation method. In addition, the utilisation of the proposed absorber as a sensor is also investigated. The dielectric and thickness sensing characteristics are analysed. The proposed multiband metamaterial absorber has the ability for utilising the terahertz region up to 2 THz. According to the results, it is found that the proposed absorber is capable of sensing unknown materials and material thickn...
Citation Formats
S. Göktepe and E. Kuhl, “Atrial and ventricular fibrillation: computational simulation of spiral waves in cardiac tissue,” Archive of Applied Mechanics, pp. 569–580, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/28133.