Electric Field Distribution around the Deep Brain Stimulation Electrode Inferred from Dielectric Measurements

Information about the spatial distribution of the electric field can be obtained by measuring the electrode impedance as a function of the diameter of the electrolyte surrounding the electrode. The non-uniform distribution of the electric field around the electrode is supported by the variation of the geometry factor (GF) with the electrical conductivity and geometry of the volume conductor. A comparison of the values obtained for the GF from experimental data, from model calculations and simulations help to understand the non-uniform distribution of the electric field. The GF calculated from four-electrode-measurements is significantly higher. GF should be used with caution in calculations of the deep brain stimulation (DBS) electrode impedance.