Assessment of the Sensitivity to Field Localization of Various Parameters During Transcranial Magnetic Stimulation

We report on an investigation of the field distribution induced inside the brain during transcranial magnetic stimulation in terms of two different head models as well as different conductivities of brain components. We simulated a new stimulator, with a conductive shield plate between a figure-of-eight coil and the head in the presence of each realistic head model, and obtained better field localization than with the conventional figure-of-eight coil. Finally, we assessed the effects of various parameters such as the head model, conductivities, stimulator type, tilt angle, operating frequency, distance of the stimulator from the head, and shield dimensions on the field localization by means of Taguchi´s design of experiments method.