Error Analysis of a New Galerkin Method to Solve the Forward Problem in Meg and Eeg Using the Boundary Element Method
نویسندگان
چکیده
Sources of brain activity, e.g., epileptic foci can be localized by measuring the magnetic eld outside the head (MEG) or by recording the electric potential on the scalp (EEG). For a successful surgery a very high localization accuracy is needed. The most often used conductor model in the source localization is an analytic sphere, which is not always adequate, and thus a realistically shaped conductor model is needed. In this paper we propose a new Galerkin method with linear basis functions to solve the forward problem in MEG and EEG using the boundary element method (BEM). Its accuracy is compared to the collocation method with constant and linear basis functions. The accuracies are determined for a unit sphere for which analytic solutions are available. The Galerkin method gives a clear improvement in the accuracy of the forward problem. For ne triangular meshes, the Galerkin method reaches a given accuracy with lower computational costs than the collocation methods.
منابع مشابه
Error analysis of a Galerkin method to solve the forward problem in MEG using the boundary element method
Sources of brain activity, e.g. epileptic foci, can be localized with Magnetoencephalography (MEG) measurements by recording the magnetic field outside the head. For a successful surgery a very high localization accuracy is needed. The most often used conductor model in the source localization is an analytic sphere, which is not always adequate, and thus a realistically shaped conductor model i...
متن کاملCrack Analysis, Using a New Coupled FE-EFG Method
To solve crack problems, some coupled methods have been developed in recent years. Most of these methods have some shortcomings such as the need for a transition region. The finite element and enriched element free Galerkin methods are widely used for this class of problems. In order to take the advantages of these methods while avoiding the disadvantages, it is essential to follow solution app...
متن کاملElement Free Galerkin Method for Static Analysis of Thin Micro/Nanoscale Plates Based on the Nonlocal Plate Theory
In this article, element free Galerkin method is used for static analysis of thin micro/nanoscale plates based on the nonlocal plate theory. The problem is solved for the plates with arbitrary boundary conditions. Since shape functions of the element free Galerkin method do not satisfy the Kronecker’s delta property, the penalty method is used to impose the essential boundary conditions. Discre...
متن کاملFast multipole acceleration of the MEG/EEG boundary element method.
The accurate solution of the forward electrostatic problem is an essential first step before solving the inverse problem of magneto- and electroencephalography (MEG/EEG). The symmetric Galerkin boundary element method is accurate but cannot be used for very large problems because of its computational complexity and memory requirements. We describe a fast multipole-based acceleration for the sym...
متن کاملNeuroelectric Current Localization from Combined EEG/MEG Data
EEG/MEG devices record external signals which are generated by the neuronal electric activity of the brain. The localization of the neuronal sources requires the solution of the neuroelectromagnetic inverse problem which is highly ill-posed and ill-conditioned. We provide an iterative thresholding algorithm for recovering neuroeletric current densities within the brain through combined EEG/MEG ...
متن کامل