ENERGY DELIVERY DEVICE AND METHODS OF USE

1 . An expandable energy delivery assembly adapted to deliver electrical energy to tissue, comprising:

an elongate device; and

an expandable portion comprising

an inflatable element, a single helical electrode disposed on the inflatable element, and at least one irrigation aperture within the inflatable element, the inflatable element secured to the elongate device, the single helical electrode making between about 0.5 and about 1.5 revolutions around the inflatable element, and the at least one irrigation aperture adapted to allow fluid to flow from within the inflatable element to outside the inflatable element.

2 . The assembly of claim 1 wherein the single helical electrode makes between about 1 and about 1.25 revolutions around the inflatable element.

3 . The assembly of claim 1 further comprising a conductive material disposed on the elongate device proximal to the expandable portion to electrically couple the single helical electrode to an electrical energy source.

4 . The assembly of claim 3 wherein the conductive material is disposed on substantially the entire elongate device proximal to the expandable portion.

5 . The assembly of claim 3 further comprising an insulation material disposed on substantially all of the conductive material on the elongate device.

6 - 7 . (canceled)

8 . The assembly of claim 1 wherein the expandable portion comprises a proximal transition section covered with a conductive material that electrically couples the helical electrode and the conductive material on the elongate device.

9 . The assembly of claim 8 further comprising an insulation material disposed on the conductive material on the transition shaped section.

10 . The assembly of claim 1 wherein the inflatable element is a balloon with a substantially cylindrical section, the single helical electrode disposed on the substantially cylindrical section.

11 . The assembly of claim 1 wherein the at least one irrigation aperture is in the inflatable element.

12 . The assembly of claim 11 wherein the at least one irrigation apertures is in the helical electrode.

13 . The assembly of claim 11 wherein the at least one irrigation aperture is not in the helical electrode.

14 . The assembly of claim 11 wherein the at least one irrigation aperture is adjacent the helical electrode.

15 - 27 . (canceled)

28 . A method of manufacturing an expandable energy delivery assembly adapted to deliver energy to tissue, comprising:

providing an inflatable element secured to an elongate device;

inflating the inflatable element; and

depositing a conductive material on an exterior surface of the inflatable element to form a single helical electrode making between about 0.5 and about 1.5 revolutions around the inflatable element.

29 . The method of claim 28 wherein depositing comprises one selected from the group consisting of vapor deposition, electroplating, electroless plating, pad printing, spraying, and ink jet.

30 . The method of claim 28 further comprising applying a mask to the inflatable element before the depositing step.

31 - 32 . (canceled)

33 . The method of claim 30 further comprising removing the mask, applying a second mask over the helical electrode, and depositing an insulation material over substantially all of the elongate device proximal to the inflatable element.

34 . The method of claim 33 wherein depositing the insulation material comprises depositing the insulation material over a transition section of the inflatable element.

35 . The method of claim 33 wherein applying the second mask comprises applying the second mask over an entire intermediate section of the inflatable element.

36 - 73 . (canceled)