Patent ID: 11911004
Assignee: NATIONAL UNIVERSITY CORPORATION SHIGA UNIVERSITY OF MEDICAL SCIENCE
Field: Medical technology (Instruments)
Classification: CPC A  B | IPC A  B

Claim 9:
10. A method for bending and extending a bending and extending device, the bending and extending device comprising:

an elastic hollow guide unit; and
a movable part to be movably inserted into the guide unit,
wherein:
the guide unit has a uniform cross-sectional shape and a uniform cross-sectional size along an entire length of the guide unit in which the movable part is inserted into the guide unit;
the movable part is constituted, either partially or entirely, of a plurality of belt-like flexible parts, which extend in an axial direction of the guide unit and are connected at distal ends;
the movable part causes the plurality of flexible parts to be bent in a direction perpendicular to the axial direction of the guide unit by sliding one of proximal ends of the plurality of flexible parts in the axial direction of the guide unit (hereinafter referred to as a flexible part sliding operation);
the distal ends of the flexible parts are inside the guide unit during the flexible part sliding operation;
when, by the flexible part sliding operation, a cross-section in which a contact point of a second flexible part of the flexible parts and an inner surface of the guide unit is present on an extending line extending from a line segment connecting the centroid of a first flexible part of the flexible parts and the axial center of the guide unit and in which the first flexible part and the second flexible part are directly or indirectly in contact with each other is generated, and when the cross-section is divided into two ranges by a predetermined straight line, the centroid of the first flexible part is not positioned in a range in which the contact point of the second flexible part and the inner surface of the guide unit is present; and
the predetermined straight line is a line that passes through the axial center of the guide unit, and that orthogonally crosses the extending line;

the method comprising:
an insertion step of inserting the movable part into the guide unit so that the movable part extends in the axial direction of the guide unit;
a sliding step of sliding a proximal end of the first flexible part, which is one of the plurality of flexible parts, relative to a proximal end of another flexible part in the axial direction of the guide unit;
an inverse sliding step of sliding the proximal end of the first flexible part in the direction opposite to the direction upon the bending;

wherein:
by the sliding step, bending is generated in the movable part at the distal ends of all of the flexible parts serving as a node in a direction perpendicular to the axial direction of the guide unit, and the movable part thus bent comes into contact with a part or the entirety of the inner surface of the guide unit, thereby causing the guide unit to be bent in the perpendicular direction;
the distal ends of the flexible parts are inside the guide unit during the sliding step; and
by the inverse sliding step, the movable part thus bent is extended and comes into contact with a part or the entirety of the inner surface of the guide unit, thereby extending the guide unit.