A method and apparatus for creating a virtual electrode to ablate bodily
tissue. The apparatus includes an outer tube, a first electrode, an inner
tube and a second electrode. The outer tube is fluidly connected to a
source of conductive fluid and defines a proximal end and a distal end.
The distal end includes an opening for delivering conductive fluid from
the outer tube. The first electrode is disposed at the distal end of the
outer tube for applying a current to conductive fluid delivered from the
outer tube. The inner tube is coaxially received within the outer tube
and is connected to a source of conductive fluid. The inner tube defines
a proximal end and a distal end, with the distal end forming an opening
for delivering conductive fluid from the inner tube. Finally, the second
electrode is disposed at the distal end of the inner tube for applying a
current to conductive fluid delivered from the inner tube. With this
configuration, upon final assembly, the distal end of the outer tube is
axially spaced from the distal end of the inner tube such that the first
electrode is spaced from the second electrode. As a result, a bi-polar
virtual electrode can be established.