A new boundary element method formulation for the forward problem solution of electro-magnetic source imaging

Numerical solution of the potential and magnetic fields far a given electrical source distribution in the human brain is the essential part of electro-magnetic source imaging. In this study, the performance of Boundary Element Method (BEM) with different surface element types is explored. A new BEM formulation is derived that makes use of isoparametric linear and quadratic elements. It is shown that, quadratic elements provides superior performance over linear elements in terms of computation time and accuracy. For example, a maximum error of 1.8% is obtained using 2048 quadratic elements for a selected dipole location. Whereas, in order to obtain such an accuracy with linear elements, this number should be in the order of ten thousands. The developed surface integration tools and selected isoparametric quadratic element type can also be used to salve the magnetic held of the neural ectivity in the cerebral cortex.
International Conference of the IEEE Engineering-in-Medicine-and-Biology-Society


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The voltage measurements on the scalp and magnetic held measurements near the scalp can be used to compute spatio-temporal evolution of electric currents across the cerebral cortex. Such a representation can be called Electro-Magnetic Source Image. In order to interpret the measured fields accurately, a realistic numerical model of the head should be prepared that includes physical properties and geometry of the individual's head. For that purpose, in this study, Finite Element Method (FEM) is used to solve...
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Akahn, Z.; Acar, C.E.; Gençer, Nevzat Güneri (Institute of Electrical and Electronics Engineers (IEEE); 2002-12-07)
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The analysis of the velocity skin effect (VSE) in electromagnetic launchers (EMLs) requires a 3-D transient finite element method, unlike magnetic skin and proximity effects. However, VSE is dominant at high speeds, and this creates convergence problems when moving or deformed mesh physics is used in a transient FEM in the 3-D analysis. Commercial finite element software cannot solve the electromagnetic aspects of such a high-speed application with a transient solver in 3-D. Although 2-D approximations can ...
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In this study, the forward problem of electrical source imaging (ESI) is solved using the Boundary Element method (BEM) with realistic head models. The realistic model consists of scalp, skull, CSF, brain and eyes. To get more accurate results quadratic elements are used in the meshes-and a new method is proposed for the generation of the quadratic mesh. An accelerated method is proposed for the solution of the potential field.
Citation Formats
I. Tanzer and N. G. Gençer, “A new boundary element method formulation for the forward problem solution of electro-magnetic source imaging,” CHICAGO, IL, 1997, vol. 19, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53473.