RESUMO
A finite difference method was used to simulate the electric fields induced in the model by a gradient wire pattern. The pattern simulated corresponded to a design used to perform peripheral nerves stimulation experiments. The size (187.8, 169.02, and 150.24 cm tall) and position (brain and neck mode) of the model, relative to the magnet, as well as the voxel dimensions (3, 6, and 9 mm) of the model were varied to assess the effect on the simulation. The locations of stimulation reported from an experiment were classified according to nerve branch and compared with the peak-simulated electric fields. Model size and location affected the magnitude of the electric field, but not the position. Model resolution affected the location of the peak field. For the smallest resolution investigated, the nerves affected by the locations of peak stimulations in the model correlated to the frequency of stimulation in experiments. Although adequate resolution is required in order to assess the electric fields induced by gradient coil operation, the simulation of electric fields may be useful in evaluating gradient coil design prior to construction.
