Development of double-electrode applicator for localized thermal therapy

A double-electrode applicator for localized thermal therapy is developed by breaking through the construction principle of the capacitive applicator. To make the beam of the electric field narrow, a ferrodielectric material is introduced as the sub-electrode. The optimum configuration of the double electrode and the material constant in each part of this applicator are investigated theoretically and experimentally. Good localised deep-heating characteristics are obtained at an operating frequency of 13.56 MHz and an output power 450 W by choosing a ferrodieletric material (BaTiO₃) with a relative permittivity of 6000 as the sub-electrode.