抄録
This paper describes an accuracy estimation of low frequency electric fields induced in a human head model calculated by the FMM-SCM-V (fast-multipole surface-charge-simulation method for voxel data) by comparing them with the true fields calculated by the EMMM-PT (equivalent multipole moment method with polar-coordinates translations). The head model is composed of seven spheres and the spheres are composed of cubic voxels having 2, 1, 0.5, or 0.34mm side length. A square-coil current (1A, 50Hz) induces eddy field in the model. The number of voxels, the number of elements, and calculation time were 106,575,801, 4,936,874, and 82 minutes, respectively, when 0.34mm size voxel model was analyzed. In this case, the maximum value and the standard deviation of the electric field error vector in gray matter region were less than 19% and 0.89% , respectively. In addition, they were less than 2.9% and 0.33%, respectively, when we intended to estimate spatially averaged field strength in a (0.34x11)3 mm3 volume region.
