	US 7,572,251 B1
	Systems and methods for electrosurgical tissue treatment
Terry S. Davison, Redwood City, Calif. (US); Jean Woloszko, Austin, Calif. (US); Michael A. Baker, Austin, Calif. (US); Hira V. Thapliyal, Los Altos, Calif. (US); and Philip E. Eggers, Dublin, Ohio (US)
Assigned to ArthroCare Corporation, Austin, Tex. (US)
Filed on Dec. 06, 1999, as Appl. No. 9/457,201.
Application 09/457201 is a continuation in part of application No. 09/248763, filed on Feb. 12, 1999, granted, now 6,149,620.
Application 09/248763 is a continuation in part of application No. 08/990374, filed on Dec. 15, 1997, granted, now 6,109,268.
Application 08/990374 is a continuation in part of application No. 08/795686, filed on Feb. 05, 1997, granted, now 5,871,469, filed on Feb. 16, 1999.
Application 08/795686 is a continuation in part of application No. 08/562232, filed on Nov. 22, 1995, granted, now 6,024,733.
Application 08/562232 is a continuation in part of application No. 08/485219, filed on Jun. 07, 1995, granted, now 5,697,281, filed on Dec. 16, 1997.
Claims priority of provisional application 60/098122, filed on Aug. 27, 1998.
Claims priority of provisional application 60/096150, filed on Aug. 11, 1998.
Int. Cl. A61M 31/00 (2006.01); A61B 17/20 (2006.01)

U.S. Cl. 604—500 [604/22]

12 Claims

1. A method for applying electrical energy to tissue comprising:

positioning an active electrode adjacent to or in contact with tissue in the presence of electrically conductive fluid;

positioning a return electrode in the presence of electrically conductive fluid; the return electrode spaced proximally from the active electrode;

applying a sufficient high frequency voltage difference between the active electrode and the return electrode to vaporize a portion of the electrically conductive fluid such that the vaporized fluid and the active electrode have a temperature below 100° C.; and

effecting ablation of at least a portion of the tissue in contact with the vaporized fluid.