A Quasi-Static Boundary Element Approach With Fast Multipole Acceleration for High-Resolution Bioelectromagnetic...

Area of Science:

• Computational electromagnetics
• Biomedical engineering
• Neuroscience

Background:

• Transcranial magnetic stimulation (TMS) requires accurate computational models for effective brain stimulation.
• Existing finite-element method (FEM) simulations are computationally intensive and time-consuming.

Purpose of the Study:

• To develop a novel, accurate, and efficient computational method for TMS simulations.
• To validate the new method against established FEM software and realistic head models.

Main Methods:

• Development of a boundary element fast multipole method (BEM-FMM) utilizing surface-charge formulation.
• Analytical computation of neighbor surface integrals for enhanced efficiency.
• Validation using five high-definition head models and a commercial TMS coil, compared against ANSYS Maxwell FEM.

Main Results:

• The BEM-FMM demonstrated excellent agreement with ANSYS Maxwell FEM simulations across all tested head models.
• The new method achieved approximately 500x speed improvement over FEM, completing simulations in ~200 seconds.
• Submillimeter field resolution was consistently provided by the BEM-FMM.

Conclusions:

• The developed BEM-FMM is a highly accurate and efficient alternative for TMS modeling.
• This method has the potential to become a real-time, high-resolution simulation tool for brain stimulation and recording technologies like TMS and magnetoencephalography.