Análisis computacional de circuitos eléctricos y geometrías de bobinas para sistemas de estimulación magnética transcraneal

Abstract

Transcranial magnetic stimulation systems have had a heyday in the last two decades, both in the development and commercialization of equipment, as well as in areas of application in medicine and research, which has made them tools for the diagnosis and treatment of important diseases of the nervous system. Most of the analyzes of the general operation are still limited to the separate study of the elements of the system. In this present work, the analysis is carried out through simulations of the electrical excitation circuit using the Matlab®/Simulink®and Micro-Cap tools, likewise, three coil geometries of transcranial magnetic stimulation systems are analyzed by using the finite element method in COMSOL Multiphysics®software. The computational analysis lies in studying the basic architecture of the electrical excitation circuit, which is made up of an RLC circuit with switching elements and power electronics, in charge of generating high-magnitude current pulses (between 1 and 3 kA) and short duration. (between 0.5 and 1250 ms). The magnitude of the current and the shape of the signal in the elements of the RLC stage are analyzed, performing a calculation of the power dissipated. This first stage is complemented with the analysis by means of the finite element method of the magnetic flux density and maximum operating temperature of three coil geometries commonly used for therapies. The computational analysis gives rise to a proposal for a system that reduces the maximum operating temperature of coil geometry by up to 20 %, maintaining the maximum magnitude of the magnetic flux density, which consists of the design of a single solenoid coil geometry with windings. concentric, which from the electrical point of view, are inductors in parallel.