Technique research to reduce electric field intensity of surface tissue in magnetics stimulation

摘要

More and more attentions are attracted in the neural tissue's magnetic stimulation for its advantages over electric stimulation, especially used in non-invasive detection of human brain or in deep nerve stimulation. Most researchers concentrated on how to develop focality in stimulation, and partly solved this question by several novel designs of the stimulation coil. But there are other problems not been solved. The electric field intensity generated by all of the coils that have been reported falls off quickly with increasing distance from the plane of the coil, so that when the induced current in the target tissue deeply under the skin exceed the threshold current, the surface tissue is exposed to the huge electric field. The tissues just under the skin may be pain or even be injured for its small electric conductivity compared with skin, specialy in deep nerve stimulation. To overcome this drawback, we proposed a new method to reduce the electric field intensity of the surface tissue, and designed the coil's structure on the basis of mathematical model and realizing physical model.