Determining the electrical impedance of the retina from a complex voltage map

A method for determining the electrical impedance of the retina from complex valued voltage measurements is described. This is an extension to our previous work which did not consider the permittivity of the retina, or an exploration of the number of voltage measurements required to form an adequate solution. The model considers inhomogeneity in permittivity and conductivity of the tissue in both the x and y directions. This framework is tested on noisy voltage data solved for a synthetic rectangular retinal section. A synthetic retinal section inclusive of fovea is also considered. Estimates of the conductivity and permittivity maps are solved for using finite element analysis for a range of down sampling factors and signal to noise ratios for the voltage data. This is done to assess the potential accuracy of this method in a physical experiment.