Electrosurgical Sealer and Divider

Abstract

An electrosurgical instrument has a movable tissue cutting mechanism, a shaft housing at least a portion of the movable tissue cutting mechanism, and a pair of opposing jaws rotatable relative to the shaft. Each jaw has an electrically conductive core member, a slot for receiving the cutting mechanism, and a sealing surface. A pin is coupled to the shaft and the jaws. The pin passes through the jaws and the cutting mechanism. A first link is rotatably coupled to the first jaw and a rod. The rod is interior of and translatable relative to the shaft. Each jaw has a coating made of a substantially non-conductive material covering a portion of the conductive core member but exposing the seal surface, whereby the coating limits an energy path from the respective conductive medium to the respective seal surface.

What is claimed is: 
     
         1 . An electrosurgical instrument comprising:
 a movable tissue cutting mechanism;   a shaft housing at least a proximal portion of the movable tissue cutting mechanism;   a pair of opposing jaws having a first jaw and a second jaw, the pair of opposing jaws shaped and configured to move between a first position for clamping and sealing tissue therebetween and an second position, each one of the pair of opposing jaws comprising an electrically conductive core member, an elongated slot for receiving the movable tissue cutting mechanism, and a sealing surface having a sealing surface area;   a pin coupled to the shaft and the jaws, wherein the pin passes through the jaws and the cutting mechanism, and wherein each one of the pair of opposing jaws is rotatable relative to the shaft, and wherein the movable tissue cutting mechanism is slidable relative to the shaft;   a conductive medium operatively coupled to each of the conductive core members; and   a first link having a distal end rotatably coupled to a proximal portion of the first jaw and a proximal end rotatably coupled to a rod, the rod interior of and translatable relative the shaft; and   wherein each one of the jaws further has a coating made of a substantially non-conductive material covering a substantial portion of the conductive core member but exposing the seal surface, whereby the coating is configured to substantially isolate the respective conductive core member and limit an energy path from the respective conductive medium to the respective seal surface.   
     
     
         2 . The instrument of  claim 1 , wherein:
 the coating comprises at least one of: overmolding, plasma spraying, detonation spraying, wire arc spraying, thermal spraying, flame spraying, high velocity oxy-fuel spraying, high velocity air fuel spraying, warm spraying, or cold spraying.   
     
     
         3 . The instrument of  claim 1 , wherein:
 the sealing surface area of each jaw extends a distance of no more than 0.8 millimeters outwardly from the periphery of the respective elongated slot.   
     
     
         4 . The instrument of  claim 3 , wherein:
 the sealing surface area extends a distance of between 0.2 millimeters and 0.7 millimeters outwardly from the periphery of the elongated slot.   
     
     
         5 . The instrument of  claim 1 , wherein:
 the coating comprises overmolding.   
     
     
         6 . The instrument of  claim 1 , wherein:
 the pair of opposing jaws is configured to have a gap between the pair of jaws when in the first position; and wherein   the gap is between 0.05 millimeters and 0.18 millimeters.   
     
     
         7 . The instrument of  claim 6 , wherein:
 the gap is between 0.05 millimeters and 0.07 millimeters.   
     
     
         8 . The instrument of  claim 1 , wherein:
 the instrument is further configured to deliver a maximum power of 50 Watts and a maximum current of 3 Amperes to tissue clamped between the jaws.   
     
     
         9 . The instrument of  claim 1 , wherein:
 the pair of jaws are further shaped to fit through a cannula having an inner diameter of 6 millimeters or less when the jaws are in the first position; and wherein   the elongated slot comprises a non-linear shape.   
     
     
         10 . The instrument of  claim 1 , wherein:
 the coating isolates the proximal portion of the jaws.   
     
     
         11 . The instrument of  claim 1 , wherein:
 the conductive medium is a wire coupled to the respective conductive core member; and the coating isolates a distal portion of the wire.   
     
     
         12 . The instrument of  claim 1 , wherein:
 the pair of opposing jaws is configured to have a gap between the pair of jaws when in the first position; wherein   the gap is between 0.05 millimeters and 0.18 millimeters; and wherein   a proximal portion of the gap is greater than a distal portion of the gap or more.   
     
     
         13 . The instrument of  claim 12 , further comprising:
 one or more travel stops to maintain the gap, the one or more travel stops adjacent the sealing surface areas.   
     
     
         14 . The instrument of  claim 13 , further comprising:
 one or more substantially non-conductive travel stops to maintain the gap.   
     
     
         15 . The instrument of  claim 1 , wherein:
 the cutting mechanism further comprises an elongated aperture therethrough; and   the pin further passes through the elongated aperture of the cutting mechanism.