Insertion assisting tool for endoscope
An insertion assisting tool for an endoscope into which an insertion section of the endoscope is inserted from a base end portion side. The insertion assisting tool may include a fluid sealing device which seals a space between a base end part of the insertion assisting tool and the endoscope insertion section, the space being formed while the insertion section of the endoscope is inserted into the base end portion side.
1. An insertion assisting tool for an endoscope into which an insertion section of the endoscope is inserted, comprising:
a substantially cylindrical tube formed of an elastic body in which a smaller opening than a diameter of a base end part of the insertion assisting tool is formed at one end and a smaller opening than a diameter of the endoscope insertion section is formed at the other end,
wherein in the tube, the opening formed at the one end is attached to the base end part of the insertion assisting tool in close contact with the base end part, the tube covers from outside of the insertion assisting tool an end portion of the base end part of the insertion assisting tool, and the insertion section is slidably inserted through the tube with the insertion section of the endoscope closely fitted in the opening formed at the other end, and
wherein the tube is formed in a size which satisfies a formula of d>a−c+(b−a)/2 where an inner diameter of the insertion assisting tool is a, a maximum diameter of the tube when the tube is attached to the insertion assisting tool is b, a diameter of an opening formed at the other end of the tube is c, and a distance from a fixing portion of the tube to the insertion assisting tool to an edge portion of the opening formed at the other end of the tube is d.
2. The insertion assisting tool for an endoscope according to claim 1 , further comprising: an inflatable and deflatable balloon attached to at least one of the insertion section of the endoscope and a tip end part of the insertion assisting tool.
3. The insertion assisting tool for an endoscope according to claim 1 , wherein a diameter of the opening formed at the other end of the tube is set at 70% to 90% of outer diameter of the insertion section.
4. The insertion assisting tool for an endoscope according to claim 1 , wherein a space between inner peripheral surface of the base end part of the insertion assisting tool and outer peripheral surface of the insertion section is set to be larger than spaces between inner peripheral surface of parts other than the base end part of the insertion assisting tool and outer peripheral surface of the insertion section.
5. The insertion assisting tool for an endoscope according to claim 1 , wherein in a first state, the smaller opening at the base end part has the diameter smaller than the diameter of the base end part and in a second state, has a diameter larger than the diameter of the base end part such that the tube covers an end portion of the base end part of the insertion assisting tool.