Method and aparatus for automated biopsy and collection of soft tissue

Abstract

A bipolar electrosurgical instrument is described which may be used for heating the inner lining of a lumen or cavity within a patient. In particular, the present invention is directed to an electrosurgical instrument including a flexible elongated tube having a proximal and a distal end, a first balloon electrode attached to the distal end of the flexible elongated tube. The first balloon electrode includes a first expandable sleeve formed from an electrically insulating material and a first electrically conductive fluid in the expandable sleeve. A first electrode is positioned in electrical contact with the first electrically conductive fluid. A return balloon electrode is spaced proximally from the first balloon electrode, wherein the return balloon electrode includes a second expandable formed from an electrically insulating material and a second electrically conductive fluid disposed within the second expandable sleeve. A return electrode is positioned in electrical contact with the second electrically conductive fluid.

What is claimed is:  
     
         1 . A bipolar electrosurgical instrument for heating the inner lining of a lumen or cavity within a patient, said electrosurgical instrument comprising: 
 a flexible elongated tube having a proximal and a distal end; 
 a first balloon electrode attached to said distal end of said flexible elongated tube wherein said first balloon electrode comprises:  
   a first expandable sleeve formed from an electrically insulating material;    a first electrically conductive fluid in said expandable sleeve 
 a first electrode in electrical contact with said first electrically conductive fluid;  
 a return balloon electrode spaced proximally from said first balloon electrode, wherein said return balloon electrode comprises:  
   a second expandable sleeve formed from an electrically insulating material;    a second electrically conductive fluid disposed within said second expandable sleeve; and 
 a return electrode in electrical contact with said second electrically conductive fluid.  
   
     
     
         2 . A bipolar electrosurgical instrument according to    claim 1   , wherein said first expandable sleeve is expanded such that a portion of said first expandable sleeve is adapted to be in contact with a first portion of said inner lining and a portion of said second expandable sleeve is adapted to be in contact with a second portion of said inner lining, wherein said second portion of said inner lining is at least twice as large in area as said first portion of said inner lining.  
     
     
         3 . A bipolar electrosurgical instrument according to    claim 2   , wherein said second expandable sleeve has a length L and wherein a proximal end of said first expandable sleeve is positioned a distance of at least 2L from a distal end of said second expandable sleeve.  
     
     
         4 . A bipolar electrosurgical instrument according to    claim 2    wherein said electrically insulating material has a lower electrical permeativity than said flexible elongated tube.  
     
     
         5 . A bipolar electrosurgical instrument according to    claim 1    further comprising a non-conducting semi-rigid support extending distally within said expandable sleeve from a distal end of said flexible elongated tube.  
     
     
         6 . A bipolar electrosurgical instrument according to    claim 5    wherein said non-conducting semi-rigid support is a spring.  
     
     
         7 . A bipolar electrosurgical instrument according to    claim 5    further comprising an end guide cap attached to a distal end of said expandable sleeve and a distal end of said non-conducting semi-rigid support, said guide cap for guiding said electrosurgical instrument into said lumen or cavity.  
     
     
         8 . A bipolar electrosurgical instrument according to    claim 1    wherein said first electrode is located within and recessed proximally from said distal end of said flexible elongated tube.  
     
     
         9 . A bipolar electrosurgical instrument according to    claim 8    wherein said first electrode is a braided metallic wire.  
     
     
         10 . A bipolar electrosurgical instrument according to    claim 1    wherein said first expandable sleeve includes a conductive coating on an inner surface thereof.  
     
     
         11 . A bipolar electrosurgical instrument according to    claim 1    wherein the electrical energy applied to said first balloon electrode is radio frequency energy at a frequency of 0.5 MHz. to 20 MHz.