Ligation device and engagement method

Abstract

A ligation device includes a first arm, a second arm, a holding tube, an operation wire, a sheath, and a link mechanism having a first link and a second link which are connected to each other and engage the holding tube with the sheath, wherein the link mechanism is configured to be switch between a disengaged configuration in which engagement between the holding tube and the sheath is released and an engaged configuration in which the holding tube is engaged with the sheath due to the operation wire.

What is claimed is: 
     
         1 . A ligation device comprising:
 a first arm;   a second arm configured to be able to move toward the first arm;   a holding tube configured to accommodate the first arm and the second arm;   an operation wire connected to at least one of the first arm or the second arm;   a sheath configured to accommodate the operation wire; and   a link mechanism including a first link that is connected to a second link, the link mechanism being configured to keep the holding tube and the sheath engaged;   wherein the link mechanism is configured to switch between a disengaged configuration, the disengaged configuration being when engagement between the holding tube and the sheath is released, and an engaged configuration, the engaged configuration being when the holding tube is engaged with the sheath due to the operation wire.   
     
     
         2 . The ligation device according to  claim 1 , wherein the first link is movable in a radial direction of the sheath by movement of the operation wire, and
 the link mechanism is switched from the engaged configuration to the disengaged configuration by moving the first link outward in the radial direction.   
     
     
         3 . The ligation device according to  claim 2 , wherein the first link is configured to move outwardly in the radial direction of the sheath by a pulling operation of the operation wire. 
     
     
         4 . The ligation device according to  claim 2 , wherein the first link includes a leg part including a first leg and a second leg configured to move together and apart;
 the second link engages with the leg part when the first leg moves towards the second leg, and   the first leg being spaced from the second leg by operation of the operation wire.   
     
     
         5 . The ligation device according to  claim 4 , wherein:
 the first link is provided in the sheath, and   the second link is provided in the holding tube.   
     
     
         6 . The ligation device according to  claim 4 , wherein:
 the first link is provided in the holding tube, and   the second link is provided in the sheath.   
     
     
         7 . The ligation device according to  claim 5 , comprising:
 a large diameter part fixed to the operation wire, the large diameter part having an outer diameter larger than that of the operation wire; and   a narrowed part provided on the first link, and in which a minimum distance between the first leg and the second leg is smaller than an outer diameter of the large diameter part and larger than the outer diameter of the operation wire,   wherein, in the first link, the narrowed part is pressed by the large diameter part of the operation wire to separate the first leg from the second leg.   
     
     
         8 . An engagement method comprising:
 using a ligation device including:
 a first arm; 
 a second arm configured to be move relative to the first arm;
 a holding tube configured to accommodate the first arm and the second arm; 
 an operation wire connected to at least one of the first arm or the second arm; 
 a sheath configured to accommodate the operation wire; 
 a first leg and a second leg that are provided at a distal end of the sheath; 
 a large diameter part provided on the operation wire and has an outer diameter larger than that of the operation wire; and 
 a narrowed part provided on the sheath wherein:
 a minimum space between the first leg and the second leg is smaller than an outer diameter of the large diameter part and larger than the outer diameter of the operation wire, the method comprising: 
 
 
   bringing the large diameter part into contact with the narrowed part by moving the operation wire in a first direction of a longitudinal axis;   moving the operation wire to press the large diameter part against the narrowed part and separating the first leg from the second leg after the large diameter part is in contact with the narrowed part;   positioning the holding tube between the first leg and the second leg after the large diameter part is pressed against the narrowed part and the first leg and second leg are separated; and   causing the first leg to move towards the second leg by moving the operation wire in a second direction opposite to and the first direction to allow the sheath to engage with the holding tube.   
     
     
         9 . A ligation device comprising:
 a first arm;   a second arm configured to be move towards the first arm;   a holding tube configured to accommodate at least one of the first arm or the second arm;   an operation wire connected to at least one of the first arm or the second arm;   a sheath configured to accommodate the operation wire; and   a link mechanism including a first link connected to a second link and configured to allow the holding tube to engage with the sheath,   wherein the link mechanism is configured to switch between a disengaged configuration in which engagement between the holding tube and the sheath is released and an engaged configuration in which the holding tube is engaged with the sheath by rotation of the holding tube relative to the sheath or rotation of the sheath relative to the holding tube.   
     
     
         10 . The ligation device according to  claim 9 , wherein the first link is provided in the sheath, a groove part extending in a circumferential direction around a longitudinal axis of the sheath is formed in the sheath,
 the second link is provided in the holding tube and includes a protrusion configured to be inserted into the groove part by rotation of the holding tube about the longitudinal axis relative to the sheath,   the link mechanism is configured to move in the engaged configuration by locking the protrusion in the groove part.   
     
     
         11 . The ligation device according to  claim 9 , wherein:
 the first link is provided in the holding tube,   a groove part extends in a circumferential direction around a longitudinal axis of the holding tube is formed in the sheath,   the second link is provided in the sheath and includes a protrusion configured to be inserted into the groove part,   the protrusion is inserted into the groove part by rotating the sheath around the longitudinal axis with respect to the holding tube, and   the link mechanism is configured to move into the engaged configuration by locking the protrusion in the groove part.   
     
     
         12 . The ligation device according to  claim 9 , wherein the link mechanism has a screw structure of a male screw and a female screw and is configured to switch between the disengaged configuration and the engaged configuration by rotating the holding tube relative to the sheath.