Electrosurgical instrument including nested knife assembly

Abstract

An electrosurgical instrument includes a handle assembly and an end effector assembly operatively coupled with the handle assembly. The end effector assembly includes a first jaw member including a first jaw housing and a first electrically conductive surface, a second jaw member including a second jaw housing and a second electrically conductive surface, and a knife assembly. The knife assembly includes a base member translatably disposed in the first jaw housing, a pivot portion coupled with the base portion, and a blade pivotally associated with the pivot portion. The knife assembly is transitionable between a retracted state in which the blade is disposed within the first jaw housing and an extended state in which the blade is disposed at least partially within the second jaw housing.

1 - 10 . (canceled) 
     
     
         11 . An end effector assembly, comprising:
 a first jaw member including a first jaw housing and a first electrically conductive surface;   a second jaw member including a second jaw housing and a second electrically conductive surface, at least one of the first or second jaw members movable relative to the other between a first position in which the first and second jaw members are disposed in spaced relation relative to one another and a second position in which the first and second jaw members cooperate to grasp tissue between the first and second electrically conductive surfaces; and   a knife assembly, including:
 a base member disposed in the first jaw housing; 
 a pivot portion coupled with the base portion; and 
 a blade pivotally associated with the pivot portion, the knife assembly pivotable between a retracted state in which the blade is disposed within the first jaw housing and an extended state in which the blade is disposed at least partially within the second jaw housing. 
   
     
     
         12 . The end effector assembly according to  claim 11 , wherein the first jaw housing includes a block having a slit defined therein, the slit configured to secure a portion of the blade in the retracted state. 
     
     
         13 . The end effector assembly according to  claim 12 , wherein the portion of the blade is secured within the slit by friction fit engagement. 
     
     
         14 . The end effector assembly according to  claim 12 , wherein the slit defines an opening substantially parallel to the second electrically conductive sealing surface. 
     
     
         15 . The end effector assembly according to  claim 11 , wherein in the retracted state, the blade is disposed entirely within the first jaw member. 
     
     
         16 . The end effector assembly according to  claim 11 , wherein in the extended state, the blade extends from the first jaw member. 
     
     
         17 . The end effector assembly according to  claim 11 , wherein the end effector assembly further includes a plurality of sensors including a first sensor in the first jaw member, a second sensor in the second jaw member, and a third sensor in the blade to detect an orientation of the blade. 
     
     
         18 . The end effector assembly according to  claim 17 , wherein the first sensor is aligned with the third sensor when the blade is in the retracted state and the second sensor is aligned with the third sensor when the blade is in the extended state. 
     
     
         19 . The end effector assembly according to  claim 11 , wherein at least one of the first and second electrically conductive surfaces includes a channel defined therein that extends along a length thereof, the channel configured to receive the blade in the extended state. 
     
     
         20 . The end effector assembly according to  claim 11 , wherein the blade is biased towards the first and second electrically conductive surfaces. 
     
     
         21 . The end effector assembly according to  claim 11 , wherein the knife assembly is translatable from a proximal portion of the first jaw member to a distal portion of the first jaw member. 
     
     
         22 . The end effector assembly according to  claim 21 , further comprising an actuation assembly including a helical gear and a worm gear, the actuation assembly operatively coupled with the base member of the knife assembly and configured to cause translation of the knife assembly. 
     
     
         23 . The end effector assembly according to  claim 11 , wherein the blade of the knife assembly includes a blade edge configured to cut tissue, the blade edge oriented away from the first and second electrically conductive sealing surfaces when the knife assembly is in the retracted state. 
     
     
         24 . The end effector assembly according to  claim 11 , wherein the pivot portion includes a plurality of circumferentially arranged and radially extending teeth corresponding to a plurality of circumferentially defined grooves defined in the base member, each tooth configured to slidably engage each groove.