Bipolar cutting and coagulating forceps

Abstract

A bipolar electrosurgical instrument comprises a handle ( 5 ), a body ( 1 ) joined to the handle, and a jaw assembly ( 12 ) joined to the body and arranged such that manipulation of the handle allows the opposed jaws of the jaw assembly to be opened and closed with respect to one another. A first of said opposed jaws ( 14 ) has at least a first coagulating electrode, and the other of said opposed jaws ( 13 ) has at least a second coagulating electrode and a cutting electrode ( 16 ) separated from the second coagulating electrode by an insulating member ( 17 ). The instrument is manipulated at the surgical site such that the jaws of the jaw assembly ( 12 ) are open with respect to one another, with the cutting electrode ( 16 ) and at least one of the first and second coagulating electrodes contacting tissue at the surgical site. A radio frequency electrosurgical signal is supplied between the cutting electrode and the at least one coagulating electrode, and the electrosurgical instrument is moved while maintaining the jaws ( 13, 14 ) in their open position so as to cut tissue at the surgical site.

1 - 14 . (canceled)  
   
   
       15 . A bipolar electrosurgical instrument according to claim  14  wherein the rail protrudes from the insulating member by a distance of between 25 and 75 microns.  
   
   
       16 . A bipolar electrosurgical instrument according to  claim 15  wherein the rail protrudes from the insulating member by a distance of between 40 and 60 microns.  
   
   
       17 . A bipolar electrosurgical instrument according to  claim 16  wherein the rail protrudes from the insulating member by a distance of approximately 50 microns.  
   
   
       18 . A bipolar electrosurgical instrument according to any of claims  14  to  17  wherein the width of the rail is between 25 and 75 microns.  
   
   
       19 . A bipolar electrosurgical instrument according to  claim 18  wherein the width of the rail is between 40 and 60 microns.  
   
   
       20 . A bipolar electrosurgical instrument according to  claim 19  wherein the width of the rail is approximately 50 microns.  
   
   
       21 . A method of electrosurgically cutting tissue at a surgical site comprising the steps of 
 (i) providing a bipolar electrosurgical instrument including a handle, a jaw assembly arranged such that manipulation of the handle allows the opposed jaws of the jaw assembly to be opened and closed with respect to one another; a first of said opposed jaws having at least a first coagulating electrode; the other of said opposed jaws having at least a second coagulating electrode and a cutting electrode separated from the second coagulating electrode by an insulating member,    (ii) providing an electrosurgical generator comprising one or more sources of RF output power, a controller operable to control the generator such that it is capable of providing a first cutting RF signal to the electrosurgical instrument or a second coagulating RF signal to the electrosurgical instrument, and, in a combined mode, to deliver both first and second RF signals, the signals being fed to the electrosurgical instrument such that, in the combined mode, the cutting signal is delivered between the cutting electrode and at least one of the first and second coagulating electrodes, and the coagulating RF signal is delivered between the first and second coagulating electrodes,    (iii) manipulating the electrosurgical instrument at the surgical site such that the jaws of the jaw assembly are open with respect to one another,    (iv) closing the jaws of the jaw assembly such that tissue at the target site is contained therebetween,    (v) supplying the combined radio frequency electrosurgical signal to the electrosurgical instrument from the electrosurgical generator,    (vi) applying a first, relatively low, pressure to the tissue by the jaw assembly in order to cause the coagulation of the tissue held therebetween, and    (vii) applying a second, relatively higher, pressure to the tissue by the jaw assembly in order to cause the cutting of the tissue.