The present invention provides an apparatus and a method for producing a virtual
electrode within or upon a tissue to be treated with
radio frequency alternating
electric current, such tissues including but not limited to brain, liver, cardiac,
prostate, breast, and vascular tissues and neoplasms. An apparatus in accordance with the present invention includes a source of super-cooled fluid for selectively providing super-cooled fluid to the
target tissue to cause a temporary cessation of cellular or electrical activity, a supply of conductive or electrolytic fluid to be provided to the
target tissue, and
alternating current generator, and a processor for creating, maintaining, and controlling the
ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of
electric power to the tissue via the virtual
electrode. A method in accord with the present invention includes delivering super-cooled fluid to the
target tissue to cause a temporary cessation of cellular or electrical activity, evaluating whether the temporary cessation of cellular or electrical activity is the desired cessation of cellular or electrical activity, and if so, delivering a
conductive fluid to the predetermined
tissue ablation site for a predetermined time period, applying a predetermined
power level of
radio frequency current to the tissue, monitoring at least one of several parameters, and adjusting either the applied power and / or the fluid flow in response to the measured parameters.