APPARATUS WITH PARTIALLY INSULATED NEEDLE FOR MEASURING TISSUE IMPEDANCE AND METHOD USING SAME

摘要

An apparatus (21) for use with a radio frequency generator (28) and an indifferent electrode (74) to treat tissue in a mammalian body includes a needle (61b) having a distal portion (65) and being adapted for coupling to the radio frequency generator and a layer of insulating material (72) extending around the needle but exposing a part (73) of the distal portion of the needle. The exposed part of the needle is sized as a function of the thicknesses of the plurality of layers of tissue to facilitate placement of the distal portion of the needle in the plurality of layers by measuring impedance between the needle and the indifferent electrode.