A method for determining surface electrode location and boundary shape using impedance measurements

We have developed an algorithm to determine the boundary shape of a homogeneous volume conductor in cases where the surface can be defined by the location of electrodes. The algorithm adjusts the positions of electrodes in space to provide the best fit to impedance data. We tested the algorithm in a computer simulation that determined electrode locations on the surface of a 10 cm diameter sphere. Legendre polynomials were used to generate simulated impedance data for 66 electrodes evenly distributed over the surface. Starting from three different inititial configurations, the algorithm located the position of the electrodes to within a mean error of 2.5 mm