System and Method for Controlling RF Output During Tissue Sealing

Abstract

An electrosurgical system for sealing tissue is disclosed. The system includes a forceps having opposing jaw members that cooperate to grasp tissue therebetween, wherein each of the jaw members includes a sealing plate that is connected to an electrosurgical generator and is configured to communicate electro surgical energy through the tissue held therebetween. The system also includes at least one sensor which determines a gap distance between the sealing plates of the jaw members and a microprocessor programmed to communicate with the at least one sensor to measure an initial gap distance between the sealing plates and to generate at least one desired gap distance value based on the initial gap distance, the microprocessor further programmed to communicate with the at least one sensor to adjust output level of the electrosurgical generator as a function of the measured gap distance during the sealing process.

1 . An electrosurgical system for sealing tissue, comprising:
 a forceps including opposing jaw members that cooperate to grasp tissue therebetween, each jaw member including a sealing plate that is connected to an electrosurgical generator and is configured to communicate electrosurgical energy through the tissue held therebetween;   at least one sensor configured to determine a gap distance between the sealing plates of the jaw members; and   a microprocessor programmed to communicate with the at least one sensor to measure an initial gap distance between the sealing plates and to generate at least one desired gap distance value based on the initial gap distance, the microprocessor further programmed to communicate with the at least one sensor to adjust an output level of the electrosurgical generator as a function of the measured gap distance during the sealing process.   
   
   
       2 . The electrosurgical system as in  claim 1 , wherein the microprocessor is further configured to generate a desired gap distance trajectory including a plurality of desired gap distance values as a function of at least one of a desired slope, starting gap distance value and desired ending gap distance value. 
   
   
       3 . The electrosurgical system as in  claim 2 , wherein the microprocessor is further configured to substantially match the measured gap distance to a corresponding desired target gap distance value and adjusts the generator to deliver the appropriate energy to the tissue. 
   
   
       4 . The electrosurgical system as in  claim 2 , wherein the desired slope, the starting gap distance value and the ending gap distance value are selected as a function of the initial gap distance. 
   
   
       5 . The electrosurgical system for sealing tissue as in  claim 1 , further comprising:
 a knife channel defined along a length of at least one of the sealing plates, the knife channel dimensioned to reciprocate a cutting mechanism therealong; and   an actuator configured to selectively advance the cutting mechanism from a first position wherein the cutting mechanism is disposed proximal to tissue held between the jaw members to at least one subsequent position wherein the cutting mechanism is disposed distal to tissue held between the jaw members.   
   
   
       6 . The electrosurgical system according to  claim 1  further comprising:
 a second sensor configured to determine at least one pre-surgical tissue parameter and transmit data pertaining to the at least one pre-surgical tissue parameter to the microprocessor.   
   
   
       7 . The electrosurgical system according to  claim 6 , wherein the at least one tissue parameter is selected from a group consisting of boundary conditions, jaw fill and tissue hydration. 
   
   
       8 . A method for sealing tissue comprising:
 grasping tissue between two or more sealing plates of an electrosurgical forceps, the sealing plates adapted to connect to an electrosurgical generator;   measuring an initial gap distance between the sealing plates;   generating at least one desired gap distance value based on the initial gap distance; and   adjusting the output of the electrosurgical generator as a function of a measured gap distance.   
   
   
       9 . The method according to  claim 8 , wherein the generating further includes generating a desired gap distance trajectory including a plurality of desired gap distance values as a function of at least one of a desired slope, starting gap distance value and desired ending gap distance value. 
   
   
       10 . The method according to  claim 9 , wherein the generating further includes selecting the desired slop, the starting gap distance value and the ending gap distance value as a function of the initial gap distance. 
   
   
       11 . The method according to  claim 8 , further comprising:
 determining at least one pre-surgical tissue parameter and transmitting data pertaining to at least one pre-surgical tissue parameter to a microprocessor.   
   
   
       12 . The method according to  claim 11 , wherein the determining further includes selecting the least one pre-surgical tissue pre-surgical parameter from a group consisting of boundary conditions, jaw fill and tissue hydration. 
   
   
       13 . A method for sealing tissue comprising:
 grasping tissue between two or more sealing plates of an electrosurgical forceps, the sealing plates configured to connect to an electrosurgical generator;   measuring an initial gap distance between the sealing plates;   generating a desired gap distance trajectory based on the initial gap distance; and   adjusting the output of the electrosurgical generator as a function of a measured gap distance.   
   
   
       14 . The method according to  claim 13 , wherein the generating further includes generating the desired gap distance trajectory including a plurality of desired gap distance values as a function of at least one of a desired slope, starting gap distance value and desired ending gap distance value. 
   
   
       15 . The method according to  claim 14 , wherein the generating further includes selecting the desired slope, the starting gap distance value and the ending gap distance value as a function of the initial gap distance. 
   
   
       16 . The method according to  claim 13 , further comprising:
 determining at least one pre-surgical tissue parameter and transmitting data pertaining to at least one pre-surgical tissue parameter to a microprocessor.   
   
   
       17 . The method according to  claim 16 , wherein the determining further includes selecting the least one pre-surgical tissue parameter from a group consisting of boundary conditions, jaw fill and tissue hydration.