An energy treatment device comprising:
- an insertion part which is capable of being inserted into a body;
- a pair of arms which has a first arm and a second arm, the first arm and the second arm being provided in a distal portion of the insertion part and being capable of performing an opening-closing operation;
- a treatment member which is attachably and detachably provided in the first arm and which performs treatment on a treatment target site;
- a locked part which is provided in the second arm and which is capable of locking the treatment member;
- and
- a manipulation part which causes the pair of arms to perform an opening-closing operation,
- wherein:
- the treatment member includes:
- a knife wire configured to have conductivity and to incise a biological tissue using electrical energy;
- and
- a locking member which is positioned with respect to the first arm, being attachable to and detachable from the first arm and capable of being locked by the locked part,
- the locked part has a retainer which is capable of holding the locking member with a force stronger than a force of the first arm to hold the locking member,
- the insertion part has a shaft to which each of the first arm and the second arm is connected so as to be swingable about a same or parallel axis lines respectively,
- the first arm includes:
- a first proximal arm which is coupled to a distal end part of the shaft and which swings with respect to the shaft between a state in which the first proximal arm extends in a first direction parallel with a longitudinal axis of the shaft and a state in which the first proximal arm inclines to the longitudinal axis and extends in a second direction radially outward from the shaft;
- and
- a first distal arm which is coupled to the first proximal arm and which swings with respect to the first proximal arm between a state in which the first distal arm extends in the first direction or the second direction in which the first proximal arm extends and a state in which the first distal arm inclines relative to the second direction in which the first proximal arm extends, and
- in operation, after the first arm and the second arm are moved to a position in which the first arm and the second arm are in proximity to each other by the opening-closing operation, the locking member held by the first arm is held by the retainer, and the locking member detaches from the first arm while the locking member is held by the retainer of the second arm through an operation in which the first arm and the second arm are separated from each other.