Efficient coil design for transcranial magnetic stimulation using computational tools

Abstract

In the last two decades, transcranial magnetic stimulation (TMS) has been used in research protocols and clinical treatment of neurological disorders. In this work, we analyze the heating of a transcranial magnetic stimulation equipment, with the aim of reducing it using a novel design of stimulation coils. The operation of the equipment is limited by the overheating of the stimulation coils, such that the continuous use of the equipment during the therapy is impossible, and the device´s life time is affected. The first stage of the analysis consists of studying the response of the electrical excitation circuit through simulations, considering the use of concentric inductors to divide the magnitude of the current. This is complemented by multiphysical analysis with coupling between the magnetic field and heat transfer of two different coil geometries, showing the spatial distribution of the generated magnetic field and temperature rise in the space surrounding the stimulation coil. The main contribution of this research is the design of a stimulation coil using the finite element method, reducing the device´s operating temperature considering a practical coil geometry.