Using domain decomposition techniques for the calculation of low-frequency electric current densities in high-resolution 3D human anatomy models

Purpose - Improved numerical calculation techniques for low-frequency current density distributions within high-resolution anatomy models caused by ambient electric or magnetic fields or direct contact to potential drops using the finite integration technique (FIT). Design/methodology/approach - The methodology of calculating low-frequency electromagnetic fields within high-resolution anatomy models using the FIT is extended by a local grid refinement scheme using a non-matching-grid formulation domain. Furthermore, distributed computing techniques are presented. Several numerical examples are analyzed using these techniques. Findings - Numerical simulations of low-frequency current density distributions may now be performed with a higher accuracy due to an increased local grid resolution in the areas of interest in the human body voxel models when using the presented techniques. Originality/value - The local subgridding approach is introduced to reduce the number of unknowns in the very large-scale linear algebraic systems of equations that have to be solved and thus to reduce the required computational time and memory resources. The use of distributed computation techniques such as, e.g. the use of a parallel solver package as PETSc follows the same goals.