Impact of Titanium Cranial Implants on the Electric Field and SAR Distribution Induced by Mobile Phones Within the User’s Head

The purpose of this study was to determine the impact of a titanium cranial implant on the electric field distribution and the amount of energy absorbed from a cell phone within the human head. Three-dimensional lifelike models of the head of the mobile phone user, a titanium cranial implant, and a smartphone model was built. The head model consisted of sixteen homogeneous, isotropic domains, with permittivity and conductivity parameters taken from the literature. Numerical calculations were performed at the mobile communication frequency of 2600 MHz for a head model with and without a titanium cranial implant, in order to determine a field perturbation introduced by the implant. Our results show that in the presence of a titanium cranial implant, the electric field amplitude and SAR (Specific Absorption Rate) are increased within the layers close to the outer surface of the model (skin, fat tissue, and muscle). On the other hand, a cranial implant leads to a lower penetration depth, decreasing the electric field amplitude and SAR inside the skull, cerebrospinal fluid, and brain.