任意導体モデルを用いた磁気刺激による渦電流分布と神経興奮部位の検討

抄録

In recent years, the contactless and non-invasive magnetic stimulation is used to diagnose the function of nerve in the clinical application. It is, however, difficult to predict distributions of eddy currents in an inhomogeneous medium like as the human brain. In order to investigate the characteristics of eddy currents in the cranium, the distributions of eddy current in the simple cranium model which is filled with the saline solution was measured by the probe made of a flexible mini-coaxial cable. Moreover, the estimation of the stimulated point in the nerve was performed by using the nerve-muscle model of a bull frog's sciatic nerve. As a result, the distribution of eddy current depends on the structure of boundary of the skull or narrow space. From the results of the nerve-muscle model in the internal acoustic meatus by the magnetic stimulation, it is showed that the nerve is easy to be stimulated at where the change of eddy current density is very large or the nerve is bent in the finite medium.