The numeric calculation of eddy current distributions in transcranial magnetic stimulation.
Transcranial magnetic stimulation (TMS) is a method to stimulate neurons in the brain. It is necessary to obtain eddy current distributions and determine parameters such as position, radius and bend-angle of the coil to stimulate target area exactly. In this study, we performed FEM-based numerical simulations of eddy current induced by TMS using three-dimentional human head model with inhomogeneous conductivity. We used double-cone coil and changed the coil radius and bend-angle of coil. The result of computer simulation showed that as coil radius increases, the eddy current became stronger everywhere. And coil with bend-angle of 22.5 degrees induced stronger eddy current than the coil with bendangle of 0 degrees. Meanwhile, when the bend-angle was 45 degrees, eddy current became weaker than these two cases. This simulation allowed us to determine appropriate parameter easier.
Tsuyama
Seichi
S
Graduate School of Information Science and Electrical Engineering, Kyushu University, Japan. tsuyama@bie.is kyushu-u.ac.jp
Hyodo
Akira
A
Sekino
Masaki
M
Hayami
Takehito
T
Ueno
Shoogo
S
Iramina
Keiji
K
D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D004553:Electric Conductivity; D004558:Electric Stimulation / Q000295:instrumentation* / Q000379:methods; D004574:Electromagnetic Fields; D004867:Equipment Design; D006801:Humans; D008280:Magnetics; D001523:Mental Disorders / Q000503:physiopathology / Q000628:therapy*; D008959:Models, Neurological; D009716:Numerical Analysis, Computer-Assisted; D050781:Transcranial Magnetic Stimulation / Q000379:methods*