US Patent 8073551 Coil electrode apparatus for thermal therapy

A single-coil RF electrode, along with an associated method of operation, has been developed for use in an RF applicator, RFA apparatus or RFA system for heating tumors, including large tumors with a single heating session. The RF electrode generally has a helical geometry, although many variations exist, and is provided with an excitation current having a frequency that is sufficient for magnetic induction and coupling of various electric and magnetic fields to produce an electric field within the volume surrounded by the coil for directly applying heat to the tissue therein.