Simulation Analysis And Optimization Design Of Magnetic Stimulation Coil Based On Real Head Model

As an important tool for brain science in the 21 st century,transcranial magnetic stimulation(TMS)is favored by the majority of scientific research experts and medical workers love because of its painless,noninvasive,non-invasive characteristics.However,transcranial magnetic stimulation still faces many challenges.For example,can we provide a high-resolution real head model for simulation,how to design a better coil for simulation and optimize it.According to the current situation of the problem,combined with the existing conditions,we made some work.Firstly,in order to solve the problem of lack of real head model for transcranial magnetic simulation,we study a new method to construct human head model by using magnetic resonance medical image data.Using the high resolution and high representative nuclear magnetic resonance data,we analyze the brain tissue structure contained in the data;study the method to create a model based on the image data,discuss the best finite element grid files that can be used for simulation;analysis the important indicator of finite element meshing,transform the grid model into the geometric model which can be used for simulation.Secondly,in order to analyze the influence of electromagnetic fields in the head by the stimulating coil,this paper builds up the transcranial magnetic stimulation simulation system based on COMSOL Multiphysics.We set simulation environment and coil parameters,establish the simulation steps,analyze the distribution of the induced electromagnetic field in the tissues of the human brain;design four different structural coils,namely traditional 8-coil,circular coil,spring 8-coil,inverted bowl-shaped 8-coil,contrast and analysis the influence of the induced electric field because of coil structure differences.Finally,in order to design a stimulating coil with better focusing effect,this paper presents a new type of coil,namely close-shaped 8-coil.We defines the evaluation index that can be used to judge the focality of the coil,propose two kinds of coil structurededuction methods,contrast and analysis the new coil and the traditional 8-coil;optimize the new coil,analysis the focality under different parameters;in order to facilitate the parametric design of the coil,this paper also established a transcranial magnetic stimulation parameter analysis system based on the traditional 8-coil and the new close-shaped 8-coil.