Conservative Finite Element Modeling of EEG and MEG on Unstructured Grids
Autor: | M. Malovichko, A.M. Razorenova, N. Yavich, Maxim V. Fedorov, Nikolay Koshev |
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Rok vydání: | 2022 |
Předmět: |
Brain Mapping
Charge conservation Quantitative Biology::Neurons and Cognition Radiological and Ultrasound Technology medicine.diagnostic_test Computer science Computation Finite Element Analysis Models Neurological Physics::Medical Physics Brain Magnetoencephalography Electroencephalography Finite element method Expression (mathematics) Computer Science Applications Matrix (mathematics) Conjugate gradient method medicine Tetrahedron Electrical and Electronic Engineering Algorithm Software |
Zdroj: | IEEE Transactions on Medical Imaging. 41:647-656 |
ISSN: | 1558-254X 0278-0062 |
DOI: | 10.1109/tmi.2021.3119851 |
Popis: | For interpretation of electroencephalography (EEG) and magnetoencephalography (MEG) data, multiple solutions of the respective forward problems are needed. In this paper, we assess performance of the mixed-hybrid finite element method (MHFEM) applied to EEG and MEG modeling. The method provides an approximate potential and induced currents and results in a system with a positive semi-definite matrix. The system thus can be solved with a variety of standard methods (e.g. the preconditioned conjugate gradient method). The induced currents satisfy discrete charge conservation law making the method conservative. We studied its performance on unstructured tetrahedral grids for a layered spherical head model as well as a realistic head model. We also compared its accuracy versus the conventional nodal finite element method (P1 FEM). To avoid modeling singular sources, we completed our computations with a subtraction approach; the derived expression for the MEG response different from earlier published and involves integration of finite quantities only. We conclude that although the MHFEM is more computationally demanding than the P1 FEM, its use is justified for EEG and MEG modeling on low-resolution head models where P1 FEM loses accuracy. |
Databáze: | OpenAIRE |
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