Coil Design And Temperature Measurement Of The Magnetic Stimulation

Magnetic stimulation is a non-invasive and painless technology to stimulate the central and peripheral neural tissues. In the past decades, magnetic stimulation has grown dramatically in popularity and been used in several applications in medical and clinical research. Current-carrying coil is a key part in transcranial magnetic stimulator. Therefore, the parameter design, the magnetic field distribution, and the temperature rising of the coil, are the key technique in the study of the magnetic stimulation.The dissertation discusses the RLC parameters of the discharge circuit of the magnetic stimulator coil. A group of parallel analyses and simulation results to the discharge waveform show that the under damping state is effect to the output of the stimulator. The structure and the electrical parameters are designed by using the circuit theory, basing on the parameters of the commercial coil (Rapid2Magstim, Co. Ltd.). The coil is designed to reach the200μs pulse width, the corresponding inductance of the coil is10μH, thus the other parameters of the coil can be acquired by simulation.The3D models of the single coil, figure-8coil, and the gyroidal circle coil are built by using the finite element method (FEM). The electrical field and the pulse waveform are simulated by FEM based on the electromagnetism. The pulse waveform and the electrical field distribution are measured basing on the simulation results. The result shows the simulations and the experiments are in good accordance.The temperature variety during the stimulating are discussed. A temperature detecting circuit is designed to measure the temperature variety during the stimulating. The temperature are measured and demarcated with different pulse frequency and different amplitude. A platinum resistant is used to detect the temperature by thermal grease. A comparison of single coil and figure-8coil has been done to study the temperature variety. The designed circuit achieves the real time temperature detection, which set the foundation of the further researching of coil cooling technique.