Combination of conventional regularization methods and genetic algorithms for solving the inverse problem of electrocardiography

Download

index.pdf

Date

2010

Author

Sarıkaya, Sedat

Metadata

Show full item record

Item Usage Stats

159
views

92
downloads

Distribution of electrical potentials over the surface of the heart, i.e., the epicardial potentials, is a valuable tool to understand whether there is a defect in the heart. However, it is not easy to detect these potentials non-invasively. Instead, body surface potentials, which occur as a result of the electrical activity of the heart, are measured to diagnose heart defects. However the source electrical signals loose some critical details because of the attenuation and smoothing they encounter due to body tissues such as lungs, fat, etc. Direct measurement of these epicardial potentials requires invasive procedures. Alternatively, one can reconstruct the epicardial potentials non-invasively from the body surface potentials; this method is called the inverse problem of electrocardiography (ECG). The goal of this study is to solve the inverse problem of ECG using several well-known regularization methods and using their combinations with genetic algorihm (GA) and finally compare the performances of these methods. The results show that GA can be combined with the conventional regularization methods and their combination improves the regularization of ill-posed inverse ECG problem. In several studies, the results show that their combination provide a good scheme for solving the ECG inverse problem and the performance of regularization methods can be improved further. We also suggest that GA can be initiated succesfully with a training set of epicardial potentials, and with the optimum, over- and under-regularized Tikhonov regularization solutions.

Subject Keywords

Mathematics.

URI

http://etd.lib.metu.edu.tr/upload/2/12611669/index.pdf
https://hdl.handle.net/11511/19354

Collections

Graduate School of Applied Mathematics, Thesis

Suggestions

OpenMETU
Core

Combination of conventional regularization methods and genetic algorithm for solving the inverse problem of electrocardiography Sarikaya, Sedat; Weber, Gerhard-Wilhelm; Serinağaoğlu Doğrusöz, Yeşim (2010-07-16) Distribution of electrical potentials over the surface of the heart, which is called the epicardial potential distribution, is a valuable tool to understand whether there is a defect in the heart. Direct measurement of these potentials requires highly invasive procedures. An alternative is to reconstruct these epicardial potentials non-invasively from the body surface potentials, which constitutes one form of the ill-posed inverse problem of electrocardiography (ECG). The goal of this study is to solve the ...
Dispersion of coupled mode-gap cavities LİAN, Jin; SOKOLOV, Sergei; Yüce, Emre; COMBRİÉ, Sylvain; De Rossi, Alfredo; Mosk, Allard P. (2015-10-01) The dispersion of a coupled resonator optical waveguide made of photonic crystal mode-gap cavities is pronouncedly asymmetric. This asymmetry cannot be explained by the standard tight binding model. We show that the fundamental cause of the asymmetric dispersion is the inherent dispersive cavity mode profile; i.e., the mode wave function depends on the driving frequency, not the eigenfrequency. This occurs because the photonic crystal cavity resonances do not form a complete set. We formulate a dispersive m...
Application of the boundary element method to parabolic type equations Bozkaya, Nuray; Tezer-Sezgin, Münevver; Department of Mathematics (2010) In this thesis, the two-dimensional initial and boundary value problems governed by unsteady partial differential equations are solved by making use of boundary element techniques. The boundary element method (BEM) with time-dependent fundamental solution is presented as an efficient procedure for the solution of diffusion, wave and convection-diffusion equations. It interpenetrates the equations in such a way that the boundary solution is advanced to all time levels, simultaneously. The solution at a requi...
Solution of linear systems in arterial fluid mechanics computations with boundary layer mesh refinement Manguoğlu, Murat; Sameh, Ahmed H.; Tezduyar, Tayfun E. (Springer Science and Business Media LLC, 2010-06-01) Computation of incompressible flows in arterial fluid mechanics, especially because it involves fluid-structure interaction, poses significant numerical challenges. Iterative solution of the fluid mechanics part of the equation systems involved is one of those challenges, and we address that in this paper, with the added complication of having boundary layer mesh refinement with thin layers of elements near the arterial wall. As test case, we use matrix data from stabilized finite element computation of a b...
A prototype compartmental model of blood pressure distribution Akhmet, Marat (Elsevier BV, 2010-06-01) We consider a system of differential equations, the behavior of whose solutions possesses several properties characteristic of the blood pressure distribution. The system can be used for a compartmental modeling [R. Bellman, Mathematical Methods in Medicine, in: Series in Modern Applied Mathematics, vol 1, World Scientific Publishing Co., Singapore, 1983; J.A. Jacquez, Compartmental Analysis in Biology and Medicine, Elsevier, New York, 19721 of the cardiovascular system. It admits a unique bounded solution ...

Citation Formats

S. Sarıkaya, “Combination of conventional regularization methods and genetic algorithms for solving the inverse problem of electrocardiography,” M.S. - Master of Science, Middle East Technical University, 2010.