Modelling and Simulating
the electrical Activity of the Heart embedded in the Torso,
Numerical Analysis and Finite Volumes Methods.
Applied Mathematics PhD thesis, Université de Nantes,
2005.
Supervision: Yves Coudière and Francois
Jauberteau.
Reviewers: P. Colli-Franzone (Pavia), R. Herbin (Marseille).
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Thèses en ligne
Abstract.
This PhD thesis deals with the two following purposes: modelling and simulation
in the field of bio mathematics on the first hand, numerical analysis and
scientific computing on the other hand.
Within the field of bio-mathematics, attention is paid to
the modelling of
complex biological systems at the whole organ scale. Namely the description of
the electrical field generated by the heart activity. This activity is multi
scale.
The micro-scale phenomena are nowadays well understood and quantitative
models are
available, describing ionic exchanges on the cell membranes.
The bidomain model presents a macro-scale homogenised version of
cell membrane models, taking the anisotropic structure of the cardiac tissues
into account.
This heart model has been coupled with a torso electrical model,
thus providing an ECG (electrocardiogram) simulator.
Finite volumes methods have been developed to solve the model.
Firstly for a simplified version of the bidomain model, classical finite
volumes schemes have been studied: stability and the convergence is proven
theoretically and tested numerically.
The complete model (heart/torso coupled system) exhibits conceptual and
technical difficulties (tissues anisotropy, coupling conditions, distorted
and unstructured meshes). To overcome these difficulties, a new class of finite
volumes schemes has been developed in 3D: DDFV methods
(Discrete Duality Finite Volumes). This method has been implemented and
used both to simulate the action potential propagation in the heart
and the ECG.
Key words. Bio mathematics ~ Finite volumes methods ~
Electrocardiology ~ Simulation and numerical modelling ~
Stability and convergence of numerical methods ~ Reaction diffusion equations