Hemostasis and transection of tissue

Abstract

A laparoscopic cautery instrument may include an elongate shaft, a handle coupled to the shaft and moveable with respect to the shaft, an insulation ring, and a monopolar cautery wire. A laparoscopic cautery instrument may include an elongate shaft, a handle coupled to the shaft and moveable with respect to the shaft, a monopolar cautery wire, and an electrical conductor.

We claim: 
     
         1 . An electrical instrument comprising an insulation ring, a first electrocautery conductor, and a shaft, wherein:
 the insulation ring and the first electrocautery conductor each form a loop attached to a distal end of the shaft;   the insulation ring and the first electrocautery conductor are each operatively coupled to the shaft so as to be separately expandable and retractable relative to the distal end of the shaft;   the insulation ring is formed at least in part by an electrical insulator; and   the first electrocautery conductor is formed at least in part by an electrical conductor.   
     
     
         2 . The instrument of  claim 1 , further comprising an electrical power source to which connector ends of the first electrocautery conductor are so coupled as to apply monopolar current to the first electrocautery conductor. 
     
     
         3 . The instrument of  claim 1 , further comprising a second electrocautery conductor affixed to an inward-facing side of the insulation ring. 
     
     
         4 . The instrument of  claim 3 , further comprising an electrical power source to which connector ends of the second electrocautery conductor and the first electrocautery conductor are so coupled as to apply bipolar current between the first and second electrocautery conductors. 
     
     
         5 . The instrument of  claim 4 , wherein the second electrocautery conductor comprises a pair of electrodes positioned at opposing locations of the insulation ring. 
     
     
         6 . The instrument of  claim 4 , wherein the second electrocautery conductor comprises a conductor loop extending along at least half of the inward-facing side of the insulation ring.