Patent ID: 8277374

Claim:
A medical instrument comprising: a propelling member provided at an insertion portion to be automatically inserted into a subject, for generating a force at the insertion portion to advance/retreat in an insertion direction of the insertion portion in the subject by rotation in contact with a body wall of the subject; a contact member provided at a more distal position in the insertion direction than the propelling member in the insertion portion to be capable of inflation/deflation so as to expand radially in a radial direction of the insertion portion, the contact member being capable of contact with the body wall when inflated; a suction opening portion provided at a position between the propelling member and the contact member in the insertion direction in the insertion portion, for bringing the propelling member in contact with the body wall at a more proximal position than the contact member in the insertion direction by sucking an atmosphere in the subject at the more proximal position than the contact member in the insertion direction in a state where the contact member is in contact with the body wall; and a suction pipeline communicating with the suction opening portion, inserted into the insertion portion and connected to a suction device on a rear end side of the insertion portion in the insertion direction.