An accurate 3-D model for magnetic stimulation of the brain cortex

We present a 3-D model for the simulation of a realistic clinical situation during magnetic stimulation. The electromagnetic problem is solved by reconstructing the inhomogeneous head tissues from magnetic resonance images and associating relative values of conductivity to each tissue. Application of Maxwell's equations in the integral form leads to an equivalent 3-D electrical network, whose solution gives the current density distribution in the brain. The high spatial resolution and rigorous electromagnetic approach make this model an accurate and useful tool for stimulator design and for estimating the efficiency and safety of this clinical methodology.

Computer modelling of brain cortex excitation by magnetic field pulses

In spite of many clinical and experimental applications, the technique of transcranial magnetic stimulation still presents obscure aspects. This especially concerns safety parameters and the exact characterization of the current induced by a single magnetic pulse. The model proposed consists of an equivalent electric network derived by Maxwell's equations and applied to discretized magnetic resonance imaging of a normal subject. This model allows accurate prediction of current distribution, charge per phase and dissipated energy.