Characterization of electromagnetic propagation effects in the human head and its application to Deep Brain Implants

This paper discusses the characterization of electromagnetic propagation effects in the human head by means of the FDTD method and analytical models. The findings are used to describe and improve the RF localization of Deep Brain Implants. Despite the inhomogeneous tissue distribution in the brain the propagation in the inner brain structure can be approximated by a spherical wave. On the other hand the transition into the airy material of the skull bone and the sinus leads to reflections and perturbation of the spherical wave front. A guided wave is excited that travels along the skull bone and causes inaccuracies for the Angle of Arrival estimation at the outer reference stations.