Patent ID: 7316683

Claim:
A treatment device for cutting living tissue, comprising: an insertion member having distal and proximal ends, at least the distal end being inserted into a body cavity, the insertion member including a notch groove formed in the distal end, the notch groove having an opening formed in an outer surface of the distal end, a bottom portion, and first and second guide portions which are extended to the bottom portion from the opening, the first guide portion being extended from the opening for receiving the living tissue from the opening, and second guide portion being extended from the first guide portion to the bottom portion and having a narrower width than that of the first guide portion for guiding the living tissue from the first guide portion to the bottom portion, the notch groove having a non-variable inner space defined by the opening, the bottom portion, and the first and second guide portions, and at least two electrodes separately provided on opposite faces of the bottom portion and aligned with the second guide portion of the distal end of the insertion member, the device being so structured that, when the living tissue is inserted into the notch groove and guided to the bottom portion from the opening along the guide portion, as the distal end of the insertion member is advanced into the body cavity, the living tissue is electrically cut by a first electrode having a first contact area for contact with the living tissue that is smaller than a second contact area of a second electrode of the at least two electrodes, wherein the bottom portion further comprises a forward surface extending along a first plane, the first plane being substantially perpendicular to an axial direction of the insertion member, wherein the first contact area comprises a first portion positioned on the forward surface and the second contact area comprises a second portion positioned on the forward surface, and wherein the second portion of the second contact area extends toward the first portion of the first contact area along the forward surface.