Computational modeling of cardiac dysfunctions

Download
2014
Berberoğlu Yılmaz, Ezgi
Computational modeling of the cardiovascular system has improved remarkably with the advances in the computer technology and mathematical modeling. The cardiac models can play a crucial role in understanding the major electromechanical, biophysical, and biochemical processes for the both healthy and pathological cases. The capability of heart models to capture the real physiological behavior depends on physiologically sound constitutive models accounting for the intrinsically non-linear, electromechanically coupled response of anisotropic cardiac tissue. It is also necessary to incorporate the efficient, robust, and stable numerical algorithms into these models. To this end, we propose a micro-structurally based, unified implicit finite element approach to the fully coupled problem of cardiac electromechanics incorporating cardiac dysfunctions. In this thesis, we formulate the coupled problem of cardiac electromechanics through the conservation of linear momentum and the excitation equation in the Eulerian setting. These equations are solved monolithically through an entirely finite element-based implicit algorithm. Different from the existing literature, the deformation gradient is multiplicatively decomposed into active and passive parts in addition to the additive split of the free energy function to model the electromechanical coupling. This framework allows us to combine the advantages of the active-stress and the active-strain approaches. The left ventricular pressure evolution is modeled by incorporating a Windkessel-like model. The proposed model is then employed to investigate different pathological cases that cover myocardial infarction, eccentric and concentric hypertrophy. The computational results are shown to be in agreement with the clinical symptoms observed in the associated dysfunction.

Suggestions

Computational Modeling of Myocardial Infarction
Berberoglu, Ezgi; Göktepe, Serdar (2014-07-19)
Recent developments in computer technology and mathematical modeling have lead to a remarkable improvement in the computational modeling of the cardiovascular system. The virtual heart models have huge potential to understand the electrophysiological and mechanical response of the heart in the healthy and pathological cases. The simulation of physidogical behavior of the heart depends on the usage of physiologically sound constitutive models besides the incorporation of the efficient, robust, and stable num...
Computational modeling of chemo-electro-mechanical coupling: A novel implicit monolithic finite element approach
Wong, J.; Göktepe, Serdar; Kuhl, E. (Wiley, 2013-10-01)
Computational modeling of the human heart allows us to predict how chemical, electrical, and mechanical fields interact throughout a cardiac cycle. Pharmacological treatment of cardiac disease has advanced significantly over the past decades, yet it remains unclear how the local biochemistry of an individual heart cell translates into global cardiac function. Here, we propose a novel, unified strategy to simulate excitable biological systems across three biological scales. To discretize the governing chemic...
Computational Models of Mind
Say, Bilge(2010)
An introduction to computational modeling in cognitive science, including computer simulation models of complex cognition, models within artificial intelligence, models based on neural mechanisms and networks, and formal and mathematical models in areas such as psychology, linguistics, and philosophy. Mathematical and computational modeling of the evolution of cognition. Models of cognition that extend beyond the boundaries of the person to include the environment, artifacts, social interactions, and culture.
Computational design of nanoantennas with improved power enhancement capabilities via shape optimization
Işiklar, Göktuǧ; Yazar, Şirin; İbili, Hande; Onay, Gülten; El Ahdab, Zeina; Ergül, Özgür Salih (2023-01-01)
Computational design and analyses of nanoantennas obtained via surface shape optimization are presented. Starting with a kernel geometry, free deformations are applied on selected surfaces to reach optimal designs that can provide improved power enhancement capabilities at desired frequencies. An in-house implementation of genetic algorithms is efficiently combined with the multilevel fast multipole algorithm developed for accurate solutions of plasmonic problems to construct the effective optimization envi...
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...
Citation Formats
E. Berberoğlu Yılmaz, “Computational modeling of cardiac dysfunctions,” M.S. - Master of Science, Middle East Technical University, 2014.