ABSTRACT
Transcranial magnetic stimulation is a technique to stimulate the human brain transcranially by pulsed magnetic fields generated by a coil positioned outside the head. When a coil positioned on the surface of the head is driven by transient electric currents, time-varying magnetic fields are generated by the coil. The magnitude of electric field is zero below the center of the coil, and is highest below the coil conductors. The current flowing in the coil is subject to a Lorentz force due to the magnetic field generated from the coil itself. The driving circuit for magnetic stimulation supplies pulsed electric currents to the stimulator coil. When the magnetic field at the location of search coil varies with time, a voltage is induced in the search coil because of electromagnetic induction. The magnetic field generated from the coil is proportional to the current flowing in the stimulator coil.
