Research on Modeling and Methodology of Transcranial Electric Stimulation System Based on Finite Element Analysis

The characteristics of the electric field induced during transcranial electrical stimulation (tES) are intricate. A systematic and comprehensive understanding of the distribution characterization of the electric field in the brain under tES is crucial for optimizing the stimulation effect and guiding the selection of stimulation schemes. Focusing on the formidable problem of selecting the optimal stimulation schemes for tES, this paper initially reconstructed a more precise model of the real head; and then conducted simulation analyses using $4 \times 1$ high-precision electrodes on the COMSOL finite element simulation platform to evaluate three different schemes: direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and combined transcranial direct and alternating current stimulation (tDCS+tACS). The simulation results indicate that the composite scheme consisting of $1 \mathrm{~mA} \mathbf{t D C S}$ and $10 \mathrm{~Hz} / \mathbf{1} \mathrm{mA}$ tACS has the optimal stimulation effect, with the induced electric field intensity of $0.42 \mathrm{~V} / \mathrm{m}$ and the focusing degree of 13.5876 in the human gray matter cortex,both of which are the optimal values. This method can offer reliable guidance for clinical application and scientific research in transcranial electrical stimulation technology.