Patent ID: 8795273

Claim:
A treatment tool for an endoscope, the treatment tool comprising: a passive electrode comprising a conductive body having: a distal external surface, a proximal external surface, a first internal surface extending through the conductive body to connect the distal external surface and the proximal external surface, wherein the first internal surface defines a first through-hole, and a second internal surface extending from the proximal external surface into the conductive body, wherein the second internal surface defines a cavity having a single cavity opening on the proximal external surface; an insulating sheath comprising an insulating body having: a first internal surface defining a second through-hole in the insulating body, wherein a portion of the first internal surface of the insulating body is provided within the first through-hole to insulate the second through-hole from the first internal surface of the conductive body of the passive electrode, and a second internal surface defining a third through-hole in the insulating body, wherein the third through-hole communicates with the cavity of the conductive body of the passive electrode through the single cavity opening on the proximal external surface of the conductive body of the passive electrode; an electric cable arranged within the third through-hole of the insulating body of the passive electrode and the cavity of the conductive body of the passive electrode, wherein the electric cable is mechanically and electrically connected to the second internal surface of the conductive body of the passive electrode; and an electrically conductive treatment instrument arranged within the second through-hole of the insulating sheath, wherein a distal end of the electrically conductive treatment instrument is configured to be advanced through the conductive body of the passive electrode to protrude from the distal external surface of the conductive body of the passive electrode to perform a treatment.