US Patent 7399299 Thermal ablation of biological tissue

An ablation device is described comprising an introducer and an electrode array. The electrode array couples to a distal end of the introducer. The electrode array includes a center member having a distal end configured to penetrate tissue and a plurality of electrodes. Proximal and distal ends of each electrode are relatively fixed. The electrodes are dynamically configurable from a retracted state to a deployed state in which the electrodes form a relatively spherical shape in a tissue volume.