Endoscopic surgery device, method of inserting endoscope and treatment tool, and method of removing endoscope and treatment tool

An endoscopic surgery device comprising:

• an endoscope which includes a linear insertion part and includes an image sensor configured to observe a body cavity;
• a treatment tool including a linear insertion part having a proximal end provided with an operation part;
• and
• an outer tube which is configured to allow each of the insertion part of the endoscope and the insertion part of the treatment tool to be movable back and forth, wherein the insertion part of the endoscope and the insertion part of the treatment tool are coupled with each other by a coupling part that is arranged inside the outer tube, the insertion part of the endoscope and the insertion part of the treatment tool are in a coupled state so as to move in an axial direction of the outer tube with an allowance amount, when either one of the insertion part of the endoscope and the insertion part of the treatment tool move back and forth within the allowance amount, then another one of the insertion part of the endoscope and the insertion part of the treatment tool does not move back and forth, and when either one of the insertion part of the endoscope and the insertion part of the treatment tool move back and forth beyond the allowance amount, then another one of the insertion part of the endoscope and the insertion part of the treatment tool will move back and forth,
• wherein the endoscopic surgery device satisfies expressions of Lt≤Ls<Lh, and Lh≥Ls1+Ls+t, where
• Lt (mm) is a length of the outer tube, Ls (mm) is a length of a hard part of the insertion part of the endoscope, Lh (mm) is a length of a hard part of the insertion part of the treatment tool, Ls1 (mm) is a minimum projection length of a distal end of the insertion part of the treatment tool with respect to a distal end of the insertion part of the endoscope, and t (mm) is the allowance amount of the insertion part of the treatment tool with respect to the insertion part of the endoscope,
• wherein the endoscopic surgery device further comprises:
• a coupling member constituting the coupling part that is arranged inside the outer tube and is configured to couple the insertion part of the endoscope to the insertion part of the treatment tool to allow the insertion part of the treatment tool to move in an axial direction of the outer tube with the allowance amount with respect to the insertion part of the endoscope,
• wherein the coupling member includes:
• a first movable object which is configured to be movable in the axial direction of the outer tube and hold the insertion part of the endoscope inserted into the outer tube;
• and
• a second movable object which is provided in the outer tube, configured to hold the insertion part of the treatment tool inserted in the outer tube, and move in the axial direction of the outer tube by the allowance amount with respect to the first movable object.