Study on the distributions of induced electric field in an inhomogeneous medium exposed a pulsed magnetic field

Magnetic stimulation, which is useful for diagnosis of nervous function because of non-invasive and painless stimulation, draws the attention of many researchers especially in transcranial research. It also has recently been used as tool of rehabilitation. Magnetic stimulation, however, retains many problems. It is difficult to locate the point of stimulation in an inhomogeneous medium accurately by magnetic stimulation. The induced eddy current is distributed in the living tissue, according to the inhomogeneous tissue and complex structure of the body. In this paper we discuss how the electric fields in the model distribute by the boundary of media with different conductivity. We prepare several different volume conductors filled with 0.9% saline solution. A pulsed magnetic field was applied to the tank model using two kinds of figure-of-8 coil. The intensity of electric field is measured by a mini coaxial cable figure-of-8 coil. The intensity of electric field is measured by a mini coaxial cable. It is suggested that the focality of eddy current in the vicinity of the boundary surface between two kinds of different conductivity media depends on media conductivities.