Validation of Numerical Simulation for Subdural Cortical Stimulation Using Spherical Phantoms and Anatomically Realistic Head Phantom

The purpose of this study is to investigate the accuracy of numerical simulation for electric brain stimulation. For this, we modelled brains using simple computational models with 2 and 3 shells, with and without realistic head geometry, and performed numerical simulations using finite element method (FEM). The corresponding head phantoms were constructed for the validation of simulation results. We implanted stimulation electrodes in the head phantom, and measured the electric potential induced by the electrodes. When comparing the electric potential obtained from numerical simulations and phantom experiments, both results showed similar trend and amplitude, with a relative difference of 13.64% on average in the realistic head model study. This result demonstrates that predicting the electric potential and its gradient (current density) using computational simulation is reliable with reasonably small deviation from the actual measurement.