Temperature indicating electrosurgical apparatus and methods

Abstract

Systems, apparatus, and methods for monitoring temperature at a region near a surgical site during a procedure. A temperature-indicating element of an electrosurgical device comprises an indicator composition adapted to undergo a change in appearance in response to a pre-defined temperature range. The change in appearance of the temperature-indicating element indicates to the operator of the device a temperature condition at the working end of the device.

1 . A method of monitoring a temperature at a surgical site during a procedure comprising: 
 providing an electrosurgical device at a surgical site during a procedure, comprising: 
 a shaft having a shaft distal end portion and a shaft proximal end portion;  
 an electrode assembly comprising at least one active electrode disposed near the shaft distal end portion and adapted to be electrically coupled to a first pole of the power supply;  
 a connector fixedly engaged to the shaft proximal end portion adapted to couple the device to the power supply;  
 at least one temperature-indicating element disposed on an exterior of the shaft to be responsive to temperature changes adjacent to the device, wherein the temperature-indicating element undergoes a change in chromatic appearance over a pre-determined temperature range; and  
   visually observing the chromatic appearance of the temperature-indicating element, wherein the appearance of the temperature-indicating element is indicative of a temperature condition at region adjacent a portion of the shaft.    
     
     
         2 . The method of  claim 1 , wherein the portion of the shaft is a distal end portion.  
     
     
         3 . The method of  claim 1 , wherein the portion of the shaft is proximal to the distal end portion.  
     
     
         4 . The method of  claim 1 , wherein the at least one temperature-indicating element comprises a thermochromic composition selected from the group consisting of a leuco dye and a liquid crystal.  
     
     
         5 . The method of  claim 2 , further comprising: 
 prior to said positioning the shaft distal end portion of the device at the surgical site;    applying energy to a target tissue at the surgical site via the device; and    adjusting or discontinuing the application of energy to the target tissue according to a chromatic appearance exhibited by the temperature-indicating element.    
     
     
         6 . The method of  claim 2 , wherein said step a) comprises estimating a temperature of a target tissue at the surgical site prior to applying energy to the target tissue via the electrosurgical device.  
     
     
         7 . The method of  claim 2 , wherein the temperature-indicating element undergoes a readily discernible color change in response to exposure of the shaft distal end portion to at least one pre-defined temperature.  
     
     
         8 . An electrosurgical instrument for applying electrical energy to tissue at a target site, the instrument comprising: 
 a shaft, a proximal end and a distal end;    a non-electrically conducting support disposed at the distal end, said support having an annular configuration and a tissue-contacting surface having an annular recess therein;    a temperature indicator positioned on said support;    an active electrode positioned within the annular recess; and    a return electrode positioned about an outer surface of said support    
     
     
         9 . The electrosurgical instrument of  claim 8  wherein said indicator is band-shaped.