Medical ablation device and method of use

Abstract

A tissue resection device includes an elongate shaft having a ceramic working end with a window and a wire-like electrode. A motor oscillates the electrode back and forth in an arc between opposing sides of the window. The working end is engaged against a tissue surface while radiofrequency current is delivered to the wire-like electrode to cut tissue received within the window. A negative pressure source may be connected to the window through an interior passageway in the elongate shaft to extract cut tissue from the working end.

1 . (canceled) 
     
     
         2 . A method of resecting tissue, comprising:
 providing an elongate shaft with a working end having a window and a motor driven electrode adapted to move back and forth in an arc between opposing sides of the window;   positioning the working end against the tissue to cause tissue to interface with the window; and   actuating the motor and an RF source to cut tissue interfacing with the window with the moving electrode, wherein the cut tissue enters an interior in the elongate shaft.   
     
     
         3 . The method of  claim 2  further comprising actuating a negative pressure source in communication with the interior passageway in the elongate shaft to extract cut tissue from the working end through the interior passageway in the elongate shaft. 
     
     
         4 . The method of  claim 2  wherein the motor driven electrode comprises a wire-like electrode, wherein actuating the motor causes the wire-like electrode to rotationally oscillate in an arc back and forth between opposing sides of the window. 
     
     
         5 . The method of  claim 4  wherein the arc ranges between 60° and 210°. 
     
     
         6 . The method of  claim 4  wherein the arc ranges between 90° and 180°. 
     
     
         7 . The method of  claim 4  wherein the electrode is rotationally oscillated in a back and forth cycle at a rate between 1 cycle per second and 50 cycles per second. 
     
     
         8 . The method of  claim 7  further comprising adjusting an oscillation rate of the electrode. 
     
     
         9 . The method of  claim 4  wherein the device the motor is operated to rotationally oscillate the wire-like blade at a first rate in one direction and at a second rate in another direction. 
     
     
         10 . The method of  claim 2  further comprising delivering RF energy to the electrode. 
     
     
         11 . The method of  claim 2  further comprising drawing a negative pressure source in an interior passageway in the elongate shaft. 
     
     
         12 . The method of  claim 11  further comprising controlling the motor operating parameters, the RF source, and the negative pressure source with a controller. 
     
     
         13 . The method of  claim 12  wherein the controller adjusts at least one of (1) the motor operating parameters in response to feedback signals from at least one of the RF source and the negative pressure source, (2) the RF parameters in response to feedback signals from at least one of the motor operating parameters and the negative pressure source, and (3) the negative pressure parameters in response to feedback signals from at least one of the motor operating parameters and the RF source. 
     
     
         14 . The method of  claim 12  further comprising stopping oscillation of the wire-like electrode in a selected position relative to the window with the controller. 
     
     
         15 . The method of  claim 14  further comprising delivering coagulation RF energy to tissue when the electrode is in the stopped position by the controller. 
     
     
         16 . The method of  claim 2  further comprising articulating a distal end of the elongate shaft using a pull-wire. 
     
     
         17 . The method of  claim 2  further comprising moving the motor driven electrode axially relative to the window. 
     
     
         18 . The method of  claim 2  wherein the wire-like electrode has a hook shape. 
     
     
         19 . The method of  claim 2  wherein the elongate shaft has a channel configured to be removably connected to a fluid to deliver a fluid to a distal portion of the shaft.