Magnetic Field Analysis Of Transcranial Magnetic Stimulation And Optimization Design Of Coil Array

Transcranial magnetic stimulation(TMS) is a new method to stimulate cortical which deveoped in the middle of 80 times in the 20th century. The technique can intactly stimulate excitable tissues with electric currents induced by time-varying magnetic fields. Comparing with electric stimulation, it has the performance of painless, valid, safe and easy to repeat and operate. It is a new method of non-invasive stimulation. Now it has been widely used in the treatment of psychiatric and brain research.Despite TMS has advantages and potential applications, the magnetic fields generated by conventional coil design have large spatial extent, leading to excitation of diverse structure with a lack of localization in the target tissues. In the magnetic stimulation, we can stimulate single or multi targets precisely only after we know the focalization of all kinds of coils and after we design and fabricate coils that can produce extremely localized fields.To solve these problems, The main research works are as follows:1) According to elementary electromagnetic theory, the magnetic fields in the cone coils and figure-of-eight coil are studied using finite element analysis software ANSYS.2) Combining MATLAB software with finite element method software ANSYS the paper compiles linear regression algorithm and improved genetic algorithm program. This method gives the analysed results by ANSYS software . After the optimization calculation we can get the current combination for the coil array. Finally the paper applies ANSYS software to validate the results and get the coil array with extremely localized fields.