Body Tissue Incision Apparatus

Abstract

The body tissue harvesting instrument is provided with a cutter which is disposed at the distal end of an insertion member that is inserted into the body to sever tissue inside the body. The cutter includes a slit that extends from the distal end toward the base end; a first high-frequency electrode disposed along the two side edges of the slit on the outer surface of the cutter body and a second high-frequency electrode disposed at the base end of the slit; and a mechanism which is disposed on both sides of the distal end of the slit in the projection of the cutter body which rotates as a result of being pressed by the tissue, and which feeds the tissue toward the interior of the slit. Parts located on both sides of the distal end of the slit in the projection may mutually separate in the thickness direction.

1 . A body tissue harvesting instrument comprising:
 an insertion member which has a distal end and a base end part wherein the distal end is inserted first into the body,   a tissue holder which is provided at the distal end of the insertion member which holds tissue inside the body so that it is capable of freely moving along the tissue, and   a cutter which is provided at the distal end of the insertion member, and which severs the tissue held by the tissue holder,   wherein the tissue holder and cutter at the distal end of the insertion member mutually separate in a first crosswise direction which crosses a longitudinal center line connecting the distal end and the proximal end part of the insertion member,   wherein the tissue holder includes a tissue holding frame which has a distal end part which projects from the distal end of the insertion member and which is far from the distal end of the insertion member, a proximal end part which is closer to the distal end of the insertion member than the distal end part, and two arms which extend in a second crosswise direction that crosses both the longitudinal center line and the first crosswise direction at both the distal end part and proximal end part, and which face each other in the direction along the longitudinal center line, and wherein the two arms of the tissue holding frame mutually diverge in the first crosswise direction.   
     
     
         2 . The body tissue harvesting instrument according to  claim 1 , wherein the tissue holder further comprises:
 a frame switching member which projects from the distal end of the insertion member, and which is capable of moving forward or backward along the longitudinal center line between a closed position where the mutual gap between the extended ends of the two arms of the tissue holding frame is closed and an open position where the gap is open.   
     
     
         3 . The body tissue harvesting instrument according to  claim 1 , wherein at least one or the other of the tissue holder or the cutter is capable of moving forward or backward along the longitudinal center line relative to the distal end of the insertion member between a facing position where the cutter and the tissue holding frame of the tissue holder face each other and a facing separation position where the cutter has been brought closer to the distal end of the insertion member than the tissue holding frame. 
     
     
         4 . The body tissue harvesting instrument according to  claim 1 , wherein the cutter comprises:
 a cutter body which includes a base end part held at the distal end of the insertion member, a projection which projects from the distal end of the insertion member, and a slit which extends from the projection toward the base end part,   a first high-frequency electrode disposed along the two side edges of the slit on the outer surface of the cutter body,   a second high-frequency electrode disposed at the base end of the slit in the cutter body, and   a feeding mechanism which is disposed on the distal end side of the slit at the projection of the cutter body, which rotates as a result of being pressed by the tissue, and which feeds the tissue toward the interior of the slit.   
     
     
         5 . The body tissue harvesting instrument according to  claim 4 , wherein the feeding mechanism of the cutter comprises two rotary members which rotate so that the parts which are disposed opposite each other on both sides of the distal end of the slit in the projection of the cutter body move in the direction from the distal end toward the base end of the slit. 
     
     
         6 . The body tissue harvesting instrument according to  claim 5 , wherein the feeding mechanism of the cutter further comprises:
 two subsidiary rotary members which rotate so that the parts which are disposed opposite each other on both sides of the base end of the slit in the base end part of the cutter body move in the direction from the distal end toward the base end of the slit, and   two gear members which engage with each of the two rotary members and each of the two subsidiary rotary members, and which move the parts that extend opposite each other along the two side edges of the slit in the direction from the distal end toward the base end of the slit in conjunction with the rotation of each of the two rotary members and each of the two subsidiary rotary members.   
     
     
         7 . The body tissue harvesting instrument according to  claim 1 , wherein the cutter comprises:
 a cutter body which includes a base end part held at the distal end of the insertion member, a projection which projects from the distal end of the insertion member, and a slit which extends from the projection toward the base end part,   a first high-frequency electrode disposed along the two side edges of the slit on the outer surface of the cutter body, and   a second high-frequency electrode disposed at the base end of the slit in the cutter body,   wherein the projection parts located on both sides of the distal end of the slit in the projection of the cutter body mutually separate in the thickness direction of the slit which crosses both the extension direction and width direction of the slit.   
     
     
         8 . The body tissue harvesting instrument according to  claim 7 , wherein the distance with which the projection parts are mutually separated in the thickness direction of the slit which crosses both the extension direction and width direction of the slit is larger than the width at the base end of the slit. 
     
     
         9 . The body tissue harvesting instrument according to  claim 1 , wherein the cutter comprises:
 a cutter body which includes a base end part held at the distal end of the insertion member, a projection which projects from the distal end of the insertion member, and a slit which extends from the projection toward the base end part,   a first high-frequency electrode disposed along the two side edges of the slit on the outer surface of the cutter body, and   a second high-frequency electrode capable of moving between the base end and distal end of the slit in the cutter body, and   wherein the width of the distal end of the slit is set larger than the width of the base end of the slit.   
     
     
         10 . The body tissue harvesting instrument according to  claim 9 , wherein the slit has a triangular form with the base end comprising one apex. 
     
     
         11 . The body tissue harvesting instrument according to  claim 9 , wherein the two side edges of the slit have a wide part of fixed width disposed on the distal end side, and a narrow part of a fixed width narrower than the wide part disposed on the base end side. 
     
     
         12 . The body tissue harvesting instrument according to  claim 9 , further comprising an energizing member provided in the cutter body, and which impels the second high-frequency electrode from the base end toward the distal end of the slit. 
     
     
         13 . The body tissue harvesting instrument according to  claim 1 , wherein the cutter comprises:
 a cutter body which includes a base end part held at the distal end of the insertion member, a projection which projects from the distal end of the insertion member, and multiple slits which extend from multiple locations in the projection toward the base end part in a mutually independent manner,   a first high-frequency electrode disposed along the two side edges of each slit on the surface of the cutter body, and   a second high-frequency electrode disposed at the base end of each slit in the cutter body, wherein the respective widths of the multiple slits mutually differ.