Development of a New TMS Coil for Small Animals Using an Inverse Problem Approach for Deep Brain Stimulation

TMS (Transcranial magnetic stimulation) is a therapy that non-invasively stimulates localized target areas of the brain by generating an induced electric field inside the brain from outside the body using a coil that generates a time-varying magnetic field. However, current TMS coils have been reported to be inadequate for deep brain stimulation, and there is a need for a coil that can achieve this. In this study, we first derived an optimal electric field distribution for deep brain stimulation. Next, based on the electric field, the optimal TMS coil geometry for stimulation was derived using an inverse problem method. Then, based on the obtained TMS coil shape, a prototype was fabricated and its performance was evaluated.