Flexible tube and insertion apparatus

Patent metadata

Field	Value
Publication number	US-10107422-B2
Application number	US-201715602827-A
Country	US
Kind code	B2
Filing date	May 23, 2017
Priority date	Dec 2, 2014
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A flexible tube includes a helical tube including a closely-wound region and a sparsely-wound region, and an outer tube covering an outer side of the helical tube. The closely-wound region includes a closely-wound portion to which a tight contact force is applied, the tight contact force allowing adjacent parts of a wire member adjacent along the longitudinal axis to become a tight contact state, a sparsely-wound portion which is arranged at a proximal side of the closely-wound portion, and a change portion which is arranged at a proximal side of the sparsely-wound portion and, has the tight contact force between the adjacent parts on the proximal side rather than the distal side along the longitudinal axis reduced more than the tight contact force of the closely-wound portion.

First claim

What is claimed is:

1. A flexible tube in a unbent state and not subject to external stress, the flexible tube comprising:
a helical tube which defines a longitudinal axis by a distal end and a proximal end of the helical tube, the helical tube being formed by a winding wire member, the helical tube including:
a closely-wound region including:
first adjacent parts of the wire member that are adjacent and closely attached along the longitudinal axis, the first adjacent parts applying contact forces between each other along the longitudinal axis,
second adjacent parts of the wire member that are arranged on a proximal side of the first adjacent parts, the second adjacent parts being adjacent and separated from each other along the longitudinal axis, and
third adjacent parts of the wire member that are arranged on a proximal side of the second adjacent parts, the third adjacent parts being adjacent and in close contact with one another along the longitudinal axis, the third adjacent parts applying contact forces between each other along the longitudinal axis, wherein the contact forces of a proximal side of the third adjacent parts along the longitudinal axis are lower than the contact forces of a distal side of the third adjacent parts along the longitudinal axis, and the contact forces of the proximal side of the third adjacent parts are lower than the contact forces of the first adjacent parts; and

a sparsely-wound region including fourth adjacent parts of the wire member which are arranged on the proximal side of the third adjacent parts, the fourth adjacent parts being adjacent and separated from each other along the longitudinal axis; and

a cylindrical outer tube which covers an outer side of the helical tube across an entire length of the helical tube, the cylindrical outer tube defining the length of the helical tube, the cylindrical outer tube including an adjuster arranged on an outer side of a boundary between the third adjacent parts of the closely-wound region and the fourth adjacent parts of the sparsely-wound region, the adjuster being configured to adjust a bending stiffness of the cylindrical outer tube.

2. The flexible tube according to claim 1 , wherein the closely-wound region includes:
fifth adjacent parts of the wire member which are arranged on a distal side of the first adjacent parts, the fifth adjacent parts being adjacent to and separated from each other along the longitudinal axis; and
sixth adjacent parts of the wire member which are arranged continuously on a distal side of the fifth adjacent parts, the sixth adjacent parts being adjacent and closely attached along the longitudinal axis, the sixth adjacent parts applying contact forces between each other along the longitudinal axis.

3. The flexible tube according to claim 1 , wherein:
a distal end portion of the third adjacent parts includes a portion having constant contact forces, each of the constant contact forces being equal to or lower than each of the contact forces of the first adjacent parts; and
a proximal end portion of the third adjacent parts includes a portion having contact forces that are each equal to or lower than each of the constant contact forces of the portion of the distal end portion of the third adjacent parts.

4. The flexible tube according to claim 1 , wherein a length of the first adjacent parts along the longitudinal axis is longer than a length of the third adjacent parts along the longitudinal axis.

5. The flexible tube according to claim 1 , wherein:
the first adjacent parts, the second adjacent parts, and the cylindrical outer tube form a first flexible portion;
the third adjacent parts and the cylindrical outer tube form a second flexible portion;
the fourth adjacent parts of the sparsely-wound region and the cylindrical outer tube form a third flexible portion;
a bending difficulty of a distal end of the second flexible portion is configured to gradually change a bending difficulty of a proximal end of the first flexible portion along the longitudinal axis; and
a bending difficulty of a proximal end of the second flexible portion is configured to gradually change a bending difficulty of a distal end of the third flexible portion along the longitudinal axis.

6. The flexible tube according to claim 1 , wherein:
the closely-wound region includes:
fifth adjacent parts which are arranged on a distal side of the first adjacent parts, the fifth adjacent parts being adjacent to and separated from each other along the longitudinal axis, and
sixth adjacent parts which are arranged on a distal side of the fifth adjacent parts, the sixth adjacent parts being adjacent to each other and closely attached along the longitudinal axis, the sixth adjacent parts applying contact forces between each other along the longitudinal axis;

the contact forces of a distal side of the sixth adjacent parts along the longitudinal axis are lower than the contact forces of a proximal side along the longitudinal axis within the sixth adjacent parts;
the contact forces of the distal side of the sixth adjacent parts are lower than the contact forces of the first adjacent parts; and
the helical tube includes a second sparsely-wound region including seventh adjacent parts of the wire member which are arranged on a distal side of the sixth adjacent parts, the seventh adjacent parts being adjacent to and separated from each other along the longitudinal axis.

7. The flexible tube according to claim 6 , wherein a length of the first adjacent parts along the longitudinal axis is longer than a length of the second sparsely-wound region along the longitudinal axis.

8. The flexible tube according to claim 1 , further comprising a braid which is arranged between the helical tube and the cylindrical outer tube.

9. The flexible tube according to claim 1 , wherein:
the first adjacent parts, the second adjacent parts, and the cylindrical outer tube form a first flexible portion;
the third adjacent parts and the cylindrical outer tube form a second flexible portion;
the fourth adjacent parts of the sparsely-wound region and the cylindrical outer tube form a third flexible portion;
the contact force within the third adjacent parts is gradually decreased towards the proximal side of the third adjacent parts;
the adjuster of the cylindrical outer tube includes:
an increasing portion which is configured to increase a bending difficulty of the cylindrical outer tube towards the proximal end of the cylindrical outer tube as the contact forces within the third adjacent parts are gradually decreased over distance towards the proximal side of the third adjacent parts, and
a decreasing portion which is arranged on a proximal side of the increasing portion, the decreasing portion being configured to gradually decrease the bending difficulty of the cylindrical outer tube towards the proximal end of the outer tube as the contact forces within the third adjacent parts are gradually decreased over distance towards the proximal side of the third adjacent parts; and

the adjuster changes properties over a longitudinal distance at a position of the adjuster such that a bending difficulty of the adjuster in the second flexible portion decreases from a bending difficulty equivalent to a bending difficulty of the first flexible portion, to a bending difficulty equivalent to a bending difficulty of the third flexible portion.

10. An insertion apparatus comprising:
an insertion section including:
a distal rigid portion;
a bending portion providing on a proximal side of the distal rigid portion, the bending portion being configured to be bent; and
the flexible tube according to claim 1 provided on a proximal side of the bending portion.

Assignees

• Olympus Corp

Inventors

• Saito Kenichiro
• Kishi Takahiro
• Hoshi Naoyuki

Classifications

• F16L11/10 Primary

  with reinforcements not embedded in the wall (F16L11/11 takes precedence) · CPC title

• A61M25/0147

  with movable mechanical means, e.g. pull wires · CPC title

• A61M2025/015

  Details of the distal fixation of the movable mechanical means · CPC title

• A61M25/0054

  with regions for increasing flexibility · CPC title

• A61B1/00064

  Constructional details of the endoscope body · CPC title