Simulated temperature increase in a head/eye model containing an intraocular retinal prosthesis

We study electromagnetic power deposition and temperature elevation in the human head due to an implantable intraocular retinal prosthesis designed to restore limited vision to individuals suffering blindness from outer retinal degeneration such as Retinitis Pigmentosa and Age-related Macula Degeneration. We have developed a high-resolution 2D human head and eye model at 0.25 mm spatial resolution in order to numerically simulate temperature elevation in the eye and surrounding tissues. A 2D finite difference time domain method (FDTD) with material independent absorbing boundary conditions is used to predict with high detail the specific absorption rate (SAR) induced via inductive powering and telemetry with the implant. A highly detailed heating pattern in the eye tissues due to SAR and power dissipation in the implanted stimulator is computed using a 2D time-domain numerical implementation of the bioheat equation.