Improved Cortical Stimulation Efficiency Using 3D Rotating Fields in Transcranial Magnetic Stimulation

This investigation proposes using 3D rotating fields for coupling the coil with neurons as an alternative to conventional Transcranial Magnetic Stimulation (TMS) techniques. This method requires calculating the field components necessary to rotate the vector field in a two-dimensional plane at a given point of interest Our results indicate that this approach activates neurons in that plane efficiently. In addition, the study demonstrates that selective activation of neurons is possible by restricting the rotation of the vector field plane to a three-dimensional sphere using an external circuit that adjusts the amplitude and phase difference between the field components. Computer simulations of human head models with orthogonal coils were used to verify the suggested approach.