WO2022208737A1 - Endoscope overtube - Google Patents

Abstract

This endoscope overtube comprises a tube body, a fixing balloon, an air-supplying device, and an airtight valve unit. The tube body has: a main lumen through which an endoscope is inserted; and an air-supplying lumen through which a gas flows. The fixing balloon is disposed on an outer circumferential surface of an apical portion of the tube body and is configured to be capable of expanding outward of the outer circumferential surface and capable of contracting toward the outer circumferential surface. The air-supplying device delivers a gas into the air-supplying lumen. The airtight valve unit has a tubular portion that is in communication with the main lumen at a rear end of the tube body. The airtight valve unit blocks a gap between the inner circumferential surface of the tubular portion and the endoscope being inserted in the main lumen through the tubular portion.

Description

overtube for endoscope

The present invention relates to an endoscope overtube.

BACKGROUND ART An endoscope overtube is known which is used for treatment using an endoscope. An endoscope overtube is used for the purpose of suppressing contact and sliding between living tissue and an endoscope when the endoscope is advanced, retracted, and rotated inside a patient's body. Since the inner peripheral surface of the endoscope overtube has a smaller sliding resistance with respect to the outer peripheral portion of the endoscope than the living tissue, the endoscope can be advanced/retracted and rotated more smoothly. As a result, the endoscope can be operated accurately and easily.
The endoscope overtube has a main tube through which the endoscope is inserted, a fixation balloon that expands and contracts outside the main tube at the distal end of the main tube, and an air supply device that supplies air to the fixation balloon. (See Patent Document 1).

Japanese Patent Application Laid-Open No. 2007-268147

The endoscope overtube is often inserted into the body using the endoscope as a guide after the endoscope has been previously inserted into the body. In this case, for example, when an endoscope is inserted into a tube having a large bend such as an intestinal tract, the endoscope and the inner wall of the tube come into contact with each other at the bend of the tube. In this state, when the endoscope overtube is inserted using the endoscope as a guide, the distal end of the endoscope overtube is pushed into the contact portion between the endoscope and the inner wall of the tube, thus preventing the tube from A portion of the inner wall can get caught between the endoscopic overtube and the side of the endoscope.
The overtube described in Patent Document 1 has openings of uniform size in the longitudinal direction, and has uniform flexibility in the longitudinal direction. For this reason, the inner wall of the pipe is likely to be involved.
Since the overtube described in Patent Document 1 cannot close the insertion port at the proximal end that is placed outside the body, liquid or gas in the body tends to flow backward from the insertion port to the outside of the body. Reflux of liquids or gases from the body can interfere with the procedure.
In the overtube disclosed in Patent Document 1, when the pressure of the first balloon becomes equal to or higher than the second pressure, the second balloon is inflated, so the pressure of the first balloon is relieved. As a result, it is possible to some extent to prevent the outer diameter from becoming too large due to excessive pressure being applied to the first balloon.
However, when the amount of air supply rises sharply, the pressure of the first balloon rises temporarily. Therefore, the air supply device in the medical equipment described in Patent Document 1 needs to be equipped with an expensive controller for controlling the amount of air supply.

As described above, the overtube described in Patent Literature 1 may impose a burden on the patient during treatment and may make smooth operation of the endoscope difficult.
There is a strong demand for an endoscope overtube that reduces the burden on a patient and enables smooth operation of the endoscope.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an endoscope overtube that reduces the burden on a patient and allows smooth operation of the endoscope. .

In order to solve the above problems, an endoscope overtube according to an aspect of the present invention includes a tube body having a main lumen through which an endoscope is inserted and an air supply lumen through which gas flows; A fixation balloon provided on the outer peripheral surface of the distal end of the outer peripheral surface and expandable outward from the outer peripheral surface and contractible toward the outer peripheral surface, an air supply device for sending the gas to the air supply lumen, and the tube An endoscope having a tubular portion communicating with the main lumen at a rear end portion of the main body, and an airtight seal closing a gap between an endoscope inserted into the main lumen through the tubular portion and an inner peripheral surface of the tubular portion. and a valve unit.

According to the above aspect, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.

1 is a schematic perspective view showing an example of an endoscope overtube according to a first embodiment of the present invention; FIG. 1 is a schematic front view showing an example of an endoscope inserted through an endoscope overtube according to a first embodiment of the present invention; FIG. FIG. 3 is a side view seen from F3 in FIG. 2 ; 1 is a schematic cross-sectional view showing an example of an endoscope overtube according to a first embodiment of the present invention; FIG. FIG. 5 is a cross-sectional view taken along line F5-F5 in FIG. 4; FIG. 5 is a cross-sectional view taken along line F6-F6 in FIG. 4; 5 is an enlarged view of F7 in FIG. 4; FIG. FIG. 3 is a schematic cross-sectional view showing an example of an airtight valve unit in the endoscope overtube according to the first embodiment of the present invention; FIG. 3 is a schematic perspective view showing an example of an airtight balloon of an airtight valve unit in the endoscope overtube according to the first embodiment of the present invention; FIG. 4 is an operation explanatory view of the airtight valve unit in the endoscope overtube according to the first embodiment of the present invention; FIG. 11 is a cross-sectional view taken along line F11-F11 in FIG. 10; 4 is a graph showing an example of the relationship between the amount of air supplied from the gas moving device and the internal pressure of the airtight balloon in the endoscope overtube according to the first embodiment of the present invention. FIG. 4 is a schematic diagram showing an example of how to use the endoscope overtube according to the first embodiment of the present invention. FIG. 4 is a schematic diagram showing an example of how to use the endoscope overtube according to the first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view illustrating the action of the distal tip in the endoscope overtube according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing an example of how to use the endoscope overtube according to the first embodiment of the present invention. FIG. 6 is a schematic perspective view showing an example of an endoscope overtube according to a second embodiment of the present invention; FIG. 18 is a cross-sectional view along line F19-F19 in FIG. 17; 19 is an enlarged view of the F19 portion in FIG. 18; FIG. FIG. 5 is a block diagram showing an example of an air supply device in an endoscope overtube according to a second embodiment of the present invention; FIG. 10 is a block diagram showing the flow of the air supply device in the endoscope overtube according to the second embodiment of the present invention during inspiration. FIG. 8 is a schematic perspective view showing a bent state of the endoscope overtube according to the second embodiment of the present invention; FIG. 23 is a cross-sectional view taken along line F23-F23 in FIG. 22; FIG. 10 is a schematic cross-sectional view showing the main part of a main tube that can be used for an endoscope overtube according to a second embodiment of the present invention; FIG. 25 is a schematic cross-sectional view showing a state in which the main tube shown in FIG. 24 is bent; FIG. 11 is a schematic front view showing an air supply device in an endoscope overtube according to a third embodiment of the present invention; FIG. 10 is a schematic front view showing the arrangement of the air supply device in the endoscope overtube according to the third embodiment of the present invention during inspiration. FIG. 11 is a block diagram showing an example of an air supply device in an endoscope overtube according to a third embodiment of the present invention; FIG. 11 is a block diagram showing the flow of the air supply device in the endoscope overtube according to the third embodiment of the present invention during inspiration. FIG. 11 is a block diagram showing an example of an air supply device in an endoscope overtube according to a third embodiment of the present invention; It is a schematic diagram explaining the effect|action of the relief valve in a manual pump. 5 is a graph showing an example of the relationship between the flow rate of air supplied by a manual pump and the amount of loss leaking from a relief valve; FIG. 11 is a schematic diagram showing the shape of a flow path of an air supply device in an endoscope overtube according to a third embodiment of the present invention; FIG. 11 is a block diagram showing a modified example (first modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention; FIG. 10 is a schematic diagram showing a flow path shape of a modified example (first modified example) of the air supply device; FIG. 11 is a schematic front view showing a modified example (second modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention. FIG. 11 is a block diagram showing a modified example (second modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention; FIG. 10 is a schematic diagram showing the shape of a flow path in a modified example (second modified example) of the air supply device; FIG. 11 is a schematic diagram showing an example of a modified example (second modified example) of the air supply device. FIG. 11 is a schematic diagram showing an example of a modified example (second modified example) of the air supply device. FIG. 11 is an operation explanatory diagram of a modified example (second modified example) of the air supply device; FIG. 11 is an operation explanatory diagram of a modified example (second modified example) of the air supply device; FIG. 11 is an operation explanatory diagram of a modified example (second modified example) of the air supply device; FIG. 11 is an operation explanatory diagram of a modified example (second modified example) of the air supply device; FIG. 11 is a schematic front view showing a modification (third modification) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention; FIG. 11 is a block diagram showing a modified example (third modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention; FIG. 11 is a schematic front view showing an example of a pressure indicator in a modified example (third modified example) of the air supply device; 48 is a bottom view of F48 in FIG. 47; FIG. FIG. 48 is a cross-sectional view taken along line F49-F49 in FIG. 47; FIG. 11 is an exploded perspective view showing an example of a collar, a coil spring, and an airtight member in a modified example (third modified example) of the air supply device; FIG. 11 is a schematic diagram showing a fixing structure of an airtight member to a collar in a modified example (third modified example) of the air supply device. FIG. 49 is a cross-sectional view taken along line F52-F52 in FIG. 48; FIG. 50 is an enlarged view of a portion F53 in FIG. 49; FIG. 11 is a schematic cross-sectional view showing the operation of a pressure indicator in a modified example (third modified example) of the air supply device; 55 is a view from F55 in FIG. 54. FIG. FIG. 3 is a schematic cross-sectional view showing a comparative example of an airtight member with a bellows structure deformed by pressure. FIG. 11 is a schematic cross-sectional view for explaining reading errors in a pressure indicator in a modified example (third modified example) of the air supply device. FIG. 11 is a schematic front view showing a modified example (fourth modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention; FIG. 11 is a schematic cross-sectional view showing the internal structure of a modified example (fourth modified example) of the air supply device. FIG. 11 is a schematic cross-sectional view showing an exploded state of a modified example (fourth modified example) of the air supply device. FIG. 61 is a cross-sectional view taken along line F61-F61 in FIG. 59; FIG. 62 is a cross-sectional view taken along line F62-F62 in FIG. 61; FIG. 11 is a block diagram showing a modified example (fourth modified example) of the air supply device; FIG. 11 is a schematic cross-sectional view showing an example of an airtight member used in a modified example (fifth modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention. FIG. 11 is a schematic cross-sectional view showing an example of an airtight member used in a modified example (sixth modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention; FIG. 66 is a cross-sectional view taken along line F66-F66 in FIG. 65; FIG. 66 is a cross-sectional view taken along line F67-F67 in FIG. 65; FIG. 11 is a schematic perspective view showing an example of an endoscope overtube according to a fourth embodiment of the present invention; FIG. 69 is a cross-sectional view taken along line F69-F69 in FIG. 68; FIG. 11 is a schematic cross-sectional view showing the main part of a pressure indicator used in an endoscope overtube according to a fourth embodiment of the present invention; FIG. 14 is a schematic cross-sectional view showing the main part of a modified example (eighth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; It is a right side view of the collar in the 8th modification. FIG. 11 is a schematic cross-sectional view showing the main part of a modified example (ninth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; It is a left view of the airtight member in the 9th modification. FIG. 20 is a schematic cross-sectional view showing the main part of a modified example (tenth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention. FIG. 20 is a left side view of a fixed frame in a tenth modified example; FIG. 20 is a schematic cross-sectional view showing the main part of a modified example (eleventh modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; FIG. 20 is a left side view of an airtight member in an eleventh modified example; FIG. 20 is a schematic cross-sectional view showing the main part of a modified example (twelfth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; FIG. 20 is a schematic cross-sectional view showing a main part of a modified example (a thirteenth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; FIG. 21 is a schematic cross-sectional view showing the main part of a modified example (a fourteenth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; FIG. 21 is a schematic cross-sectional view showing the main part of a modified example (a fifteenth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; FIG. 21 is a schematic perspective partial cross-sectional view showing a main part of a modified example (sixteenth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; FIG. 20 is a right side view of a collar used in a modified example (16th modified example) of the pressure indicator. FIG. 85 is a cross-sectional view taken along line F85-F85 in FIG. 84; FIG. 20 is a perspective view of an airtight member used in a modification (sixteenth modification) of the pressure indicator; FIG. 87 is a sectional view taken along line F87-F87 in FIG. 86; FIG. 87 is a cross-sectional view taken along line F88-F88 in FIG. 86; FIG. 20 is a schematic perspective partial cross-sectional view showing a main part of a modified example (a seventeenth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention; 89. It is an enlarged view of the F90 part in FIG. FIG. 11 is a schematic front view showing an example of an air supply device used in an endoscope overtube according to a fifth embodiment of the present invention; 92 is an enlarged view of the F92 portion in FIG. 91; FIG. FIG. 20 is a schematic cross-sectional view showing an example of a modification (eighteenth modification) of the limiter used in the endoscope overtube according to the fifth embodiment of the present invention; FIG. 94 is a schematic view of F94 in FIG. 93; FIG. 11 is a schematic cross-sectional view showing an example of an airtight valve unit used in an endoscope overtube according to a sixth embodiment of the present invention; FIG. 11 is an operation explanatory diagram of an airtight valve unit used in an endoscope overtube according to a sixth embodiment of the present invention; FIG. 21 is a schematic cross-sectional view showing a modification (a nineteenth modification) of the airtight valve unit used in the endoscope overtube according to the sixth embodiment of the present invention; FIG. 20 is an operation explanatory diagram of a modified example (a nineteenth modified example) of the airtight valve unit; FIG. 20 is a schematic cross-sectional view showing a modification (twentieth modification) of the airtight valve unit used in the endoscope overtube according to the sixth embodiment of the present invention; FIG. 21 is a schematic perspective view showing an example of an endoscope overtube according to a seventh embodiment of the present invention; FIG. 101 is a cross-sectional view taken along line F101-F101 in FIG. 100; FIG. 102 is a cross-sectional view taken along line F102-F102 in FIG. 101; FIG. 104 is a cross-sectional view taken along line F103-F103 in FIG. 103; FIG. 4 is a schematic diagram showing an example of performing endoscopic full-thickness resection using a conventional overtube. FIG. 14 is a schematic diagram showing an example of how to use the endoscope overtube according to the seventh embodiment of the present invention. 106 is an enlarged view of F106 part in FIG. 105; FIG. FIG. 14 is a schematic diagram showing an example of how to use the endoscope overtube according to the seventh embodiment of the present invention. 108 is an enlarged view of F108 part in FIG. 107; FIG. FIG. 21 is a cross-sectional view showing an example of how to use the endoscope overtube according to the seventh embodiment of the present invention; FIG. 21 is a cross-sectional view showing an example of how to use the endoscope overtube according to the seventh embodiment of the present invention; FIG. 21 is a cross-sectional view showing a modification (twenty-first modification) of the method of using the endoscope overtube according to the seventh embodiment of the present invention; FIG. 21 is a cross-sectional view showing a modification (twenty-first modification) of the method of using the endoscope overtube according to the seventh embodiment of the present invention; FIG. 21 is a cross-sectional view showing a modification (twenty-first modification) of the method of using the endoscope overtube according to the seventh embodiment of the present invention; FIG. 22 is a cross-sectional view showing a modified example (22nd modified example) of the distal end fixing portion used in the endoscope overtube of the seventh embodiment of the present invention; FIG. 11 is a cross-sectional view showing the operation of a modified example (22nd modified example) of the distal end fixing portion; FIG. 21 is a schematic cross-sectional view showing a modification (twenty-third modification) of the distal end fixing portion used in the endoscope overtube according to the seventh embodiment of the present invention; 117 is a cross-sectional view taken along line F117-F117 in FIG. 116; FIG. FIG. 11 is a schematic cross-sectional view showing an example of a diameter-reduced state of a modified example (a twenty-third modified example) of the distal end fixing portion; FIG. 21 is a schematic perspective view showing an example of an endoscope overtube according to an eighth embodiment of the present invention; FIG. 120 is a cross-sectional view taken along line F120-F120 in FIG. 119; FIG. 121 is a cross-sectional view taken along line F121-F121 in FIG. 120; FIG. 121 is a cross-sectional view taken along line F122-F122 in FIG. 120; FIG. 123 is a cross-sectional view along line F123-F123 in FIG. 121; FIG. 20 is a cross-sectional view showing an example of how to use the endoscope overtube according to the eighth embodiment of the present invention; FIG. 20 is a cross-sectional view showing an example of how to use the endoscope overtube according to the eighth embodiment of the present invention; FIG. 20 is a cross-sectional view showing an example of how to use the endoscope overtube according to the eighth embodiment of the present invention; FIG. 20 is a cross-sectional view showing an example of how to use the endoscope overtube according to the eighth embodiment of the present invention; FIG. 20 is a cross-sectional view showing an example of how to use the endoscope overtube according to the eighth embodiment of the present invention;

Embodiments of the present invention will be described below with reference to the accompanying drawings. In all the drawings, even when the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common explanations are omitted.

[First embodiment]
An endoscope overtube according to a first embodiment of the present invention will be described.
FIG. 1 is a schematic perspective view showing an example of an endoscope overtube according to a first embodiment of the present invention.

An overtube 1 shown in FIG. 1 is an example of an endoscope overtube according to the present embodiment.
The overtube 1 has a main tube 2 (tube body), a fixation balloon 3 , a distal tip 4 , a grip portion 5 , an airtight valve unit 6 , an airtight valve operating tube 7 , and an air supply device 10 .
The overtube 1 is an elongated member that is inserted into the patient's body and allows an endoscope to pass through it. The distal tip 4 , the fixation balloon 3 , and the main tube 2 are arranged in this order from the distal end toward the proximal end in the insertion direction of the overtube 1 .

Hereinafter, regarding each component of the overtube 1 as well, the end closer to the distal end of the overtube 1 will be referred to as the distal end, and the end closer to the rear end of the overtube 1 will be referred to as the distal end based on the arrangement in the longitudinal direction of the overtube 1 when assembled. may be referred to as the trailing edge. A portion near the front end of each component may be called a front end portion, and a portion near the rear end thereof may be called a rear end portion. Unless otherwise specified, a tip may or may not include a tip. Similarly, the trailing edge may or may not include the trailing edge.

The distal tip 4, the fixation balloon 3, and the main tube 2 form an insertion portion I in the overtube 1, which is inserted into the body. The fixation balloon 3 is operated by the operator to take a diameter-expanded state and a diameter-reduced state. FIG. 1 depicts the fixation balloon 3 in a diameter-expanded state. When the insertion portion I is inserted into the body, the fixation balloon 3 is reduced in diameter. In the contracted state, the fixation balloon 3 is folded and close to the main tube 2 . As a result, the outer diameter of the fixation balloon 3 is reduced to approximately the same size as the outer diameter of the main tube 2 .
In the overtube 1, the rear end of the main tube 2, the airtight valve unit 6, the airtight valve operation tube 7, and the air supply device 10 are arranged outside the patient's body.
The insertion point of the overtube 1 is not particularly limited as long as it is inside the patient's body. The overtube 1 is particularly suitable for use in inserting an endoscope into an organ with many bends, such as the intestine. An example in which the overtube 1 is inserted into the intestinal tract will be described below.

An example of an endoscope inserted through the overtube 1 will be described.
FIG. 2 is a schematic front view showing an example of an endoscope inserted through an endoscope overtube according to the first embodiment of the invention. 3 is a side view of F3 in FIG. 2. FIG.

As shown in FIG. 2, the endoscope 11 has a distal end portion 12 and an endoscopic treatment tool E. As shown in FIG.
The distal end portion 12 is provided at the distal end of an insertion portion of the endoscope 11 that is inserted into the patient's body. The tip 12 is rigid and cylindrical. The rear end of the distal end portion 12 is connected to the distal end of the bending portion 17 in the insertion portion. For example, the bending portion 17 has a plurality of articulation rings connected thereto, and can be bent vertically and horizontally by pulling an operation wire extending in the longitudinal direction of the insertion section along the articulation rings. The rear end of the bending section 17 is connected to the distal end of the flexible tube section in the insertion section. An operation section for performing various operations in the endoscope 11 is connected to the rear end of the flexible tube section. For example, the operation section can operate the bending direction and bending amount of the bending section 17 .
As shown in FIG. 3, a tubular treatment instrument channel 12b through which a treatment instrument is inserted and a nozzle 12f through which a fluid can be passed are opened in a distal end face 12a of the distal end portion 12. As shown in FIG.
The treatment instrument channel 12b is inserted through the inside of the insertion section. A rear end portion of the treatment instrument channel 12b is connected to a forceps opening into which a treatment instrument is inserted.
The nozzle 12f is inserted inside the insertion portion. A rear end portion of the nozzle 12f is connected to a fluid supply port for supplying fluid.
A tip surface of an imaging lens 12c that acquires an image in front of the tip portion 12 and light exit surfaces of light guides 12d and 12e that illuminate the front portion of the tip portion 12 are arranged on the tip surface 12a.

As shown in FIG. 2 , the endoscope treatment instrument E has a grasping device 14 and an endoscope cap 13 that supports the grasping device 14 and is attached to the distal end portion 12 .
The grasping device 14 includes a long flexible elongated member 14a, a grasping portion 14b connected to the distal end of the elongated member 14a for grasping a living tissue, a connector 14c provided on the rear end side of the grasping portion 14b, have
Elongated member 14a is, for example, a coil sheath. The grasping part 14b has a pair of grasping pieces that can be opened and closed, and can grasp a biological tissue between the pair of grasping pieces. The connector 14c is provided, for example, between the elongated member 14a and the grip portion 14b, and has a through hole 14d penetrating in a direction orthogonal to the longitudinal direction of the elongated member 14a.

The endoscope cap 13 has a hood portion 13b, a cap portion 13a, a channel tube 15, and a connecting member 16. As shown in FIG.
Hereinafter, in the description of the endoscope cap 13, the up-down direction and the left-right direction may be used. The vertical direction and the horizontal direction are the radial directions of the receptacle 13b. The vertical direction is the direction in which the longitudinal axis of the receptacle 13b and the longitudinal axis of the channel tube 15 are aligned. The left-right direction is orthogonal to the up-down direction and the axial direction of the distal end portion 12 . The up-down direction and left-right direction of the endoscope cap 13 may correspond to the up-down direction and left-right direction in the operation of the bending portion 17 of the endoscope 11, respectively.

The hood portion 13 b is substantially cylindrical and is attached to the outer peripheral surface of the distal end portion 12 . An abutment portion 13d against which the tip surface 12a of the tip portion 12 is abutted protrudes toward the center from the inner peripheral portion on the tip side of the receptacle portion 13b. As shown in FIG. 3, when viewed from the distal end side of the distal end portion 12, the abutment portion 13d forms a circular opening that opens outward from the treatment instrument channel 12b, the imaging lens 12c, and the light guides 12d and 12e. there is
The hood portion 13b is fitted to the outer peripheral surface of the distal end portion 12, and is fixed to the distal end portion 12 with the abutting portion 13d in contact with the distal end surface 12a. The hood portion 13 b may be fixed to the tip portion 12 by friction between the inner peripheral surface of the hood portion 13 b and the outer peripheral surface of the tip portion 12 . The hood portion 13 b may be fixed to the tip portion 12 by a fixing tape or adhesive interposed between the inner peripheral surface of the hood portion 13 b and the outer peripheral surface of the tip portion 12 .

Hood portion 13 b has a pair of support holes 13 c for supporting connecting member 16 . The pair of support holes 13c are provided at positions that are spaced apart from each other in the circumferential direction of the receptacle 13b and face each other in the left-right direction. Each support hole 13c extends radially through the hood portion 13b from the outer peripheral surface to the inner peripheral surface of the hood portion 13b.
Each support hole 13c is formed on the rear end side of the hood portion 13b relative to the abutment portion 13d, and is located on the distal end side of the hood portion 13b relative to the distal end of a channel tube 15, which will be described later.
A rear end portion of the hood portion 13b is formed with a convex portion 13e through which a fixing hole 13f penetrates in the longitudinal direction of the hood portion 13b.

The cap portion 13a is a substantially annular member coaxial with the hood portion 13b, and protrudes from the tip of the hood portion 13b in the longitudinal direction of the hood portion 13b. The longitudinal dimension of the cap portion 13a is such that the focal length of the imaging lens 12c is also short, and the focal position of the imaging lens 12c is located near the tip of the cap portion 13a. In one design example of the endoscope 11, the focal length of the imaging lens 12c is 10 mm, and the length of the cap portion 13a is 5 mm.

The channel tube 15 is an elongated member through which the elongated member 14a is inserted. The channel tube 15 extends substantially parallel to the longitudinal direction of the receptacle 13b. Inside the channel tube 15, a channel 15a, which is a through hole through which the elongated member 14a can advance and retreat, extends in the longitudinal direction.
The tip portion of the channel tube 15 is fixed to the abutment portion 13d while being inserted through a fixing hole 13f formed in the convex portion 13e. A method for fixing the channel tube 15 may be adhesion using an adhesive or heat sealing.

The connecting member 16 is supported by the hood portion 13 b and connects the hood portion 13 b and the grip device 14 . The connecting member 16 is an elongated linear member such as thread. The connecting member 16 is preferably a member that is flexible and has little or no stretch in the longitudinal direction, such as a soft thread. The connecting member 16 may be a wire instead of the thread.
The connecting member 16 is arranged outside the receptacle 13b and extends between the pair of support holes 13c via the through holes 14d of the connector 14c.
Both ends of the connecting member 16 are inserted into the support holes 13c from the outside toward the inside. Both ends of the connecting member 16 arranged in the hood portion 13b are engaged with the support holes 13c from the inside of the hood portion 13b in a state of being prevented from coming off, for example, by knots formed at both ends.
Thereby, the connecting member 16 is supported swingably with respect to the receptacle 13b with the pair of support holes 13c as fulcrums.

The gripping portion 14b is moved between a fully retracted position indicated by solid lines in FIG.
The maximum retraction position is a position where the grip portion 14b or the connector 14c abuts against the tip of the channel tube 15 and is prevented from moving toward the rear end.
When the elongated member 14a is pushed forward in the longitudinal direction from the maximum retracted position, the connector 14c together with the connecting member 16 swings from the upper side to the lower side with the support hole 13c as a fulcrum. As a result, the grip portion 14b moves to the lowered position in which the grip portion 14b is lowered from the upper side to the lower side in front of the cap portion 13a.

The lowered position changes in a vertical range in front of the distal end portion 12 according to the extrusion length of the elongated member 14a. Therefore, by appropriately changing the extrusion length of the elongated member 14a, the grasping portion 14b can be brought closer to the affected area requiring treatment.
When the grasping portion 14b moves to a position where the living tissue can be grasped, the living tissue of the affected area can be grasped by opening and closing the grasping portion 14b.
When the elongated member 14a is pulled longitudinally rearward, the gripping portion 14b rises in the opposite direction and returns from the lowered position to the maximum retracted position.
When the gripping portion 14b moves toward the maximum retraction position while gripping the living tissue, the living tissue gripped by the gripping portion 14b is lifted upward.
Further, when the grasping portion 14b approaches the maximum retraction position, the living tissue approaches the distal end portion 12. As shown in FIG. Since the cap portion 13a protrudes from the distal end portion 12, the living tissue does not come closer to the distal end surface 12a than the protruding amount of the cap portion 13a. Therefore, the living tissue that is lifted and approaches the distal end surface 12a while being separated from the distal end surface 12a can be observed within the visual field range of the imaging lens 12c.
In this state, for example, a treatment tool such as a high-frequency knife can be drawn out from the treatment tool channel 12b to excise the raised living tissue in front of the distal end surface 12a. For example, when the living tissue is a diseased tissue, the diseased tissue can be exfoliated or completely excised with a treatment tool such as an electric scalpel.

As shown in FIG. 3, the endoscope 11 has a convex portion 13e protruding radially outward from a substantially circular cap portion 13a. When viewed from the direction, the inner diameter must be larger than the outer diameter of the endoscope cap 13 plus the height of the projection 13e.

Now, let us return to the description of the overtube 1 .
FIG. 4 is a schematic cross-sectional view showing an example of the endoscope overtube according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line F5-F5 in FIG. FIG. 6 is a cross-sectional view along line F6-F6 in FIG.

As shown in FIG. 4, the main tube 2 has a distal tip 4 connected to its distal end and a grip portion 5 connected to its rear end. A fixation balloon 3 is fixed to the outer circumference of the main tube 2 near the distal tip 4 . However, FIG. 4 depicts a state in which the diameter of the fixation balloon 3 is expanded.
The length of the main tube 2 is the length required for the site into which the endoscope 11 is inserted.
As shown in FIG. 5, the main tube 2 is a multi-lumen tube in which a first lumen 2c (main lumen) and a second lumen 2e (air supply lumen) are formed in the longitudinal direction.
The first lumen 2c is a circular hole having an inner diameter through which the endoscope 11 can be inserted. The first lumen 2c extends through the main tube 2 in the longitudinal direction. The first lumen 2c is surrounded by a tube wall 2a (constant thickness portion) having a constant thickness.

The second lumen 2 e is an air supply lumen for circulating air supplied from the air supply device 10 to the fixation balloon 3 . The inner diameter of the second lumen 2e is smaller than the inner diameter of the first lumen 2c. The inner diameter of the second lumen 2e depends on the material of the main tube 2, but may be, for example, 0.5 mm or more and 3.0 mm or less.
The second lumen 2e is radially adjacent to the first lumen 2c and extends parallel to the second lumen 2e in the longitudinal direction of the first lumen 2c.
A portion of the tube wall 2a of the second lumen 2e extends in the longitudinal direction of the first lumen 2c at a thick portion 2b protruding radially outward.
Therefore, the outer peripheral surface 2d of the main tube 2 is formed by the tube wall 2a surrounding the first lumen 2c and the thick portion 2b that protrudes radially outward from the tube wall 2a. The cross-sectional shape of the outer peripheral surface 2d is substantially circular with the thick portion 2b protruding from the circular tube wall 2a.
2 d of outer peripheral surfaces which form the top part of the protrusion direction in the thick part 2b are smooth curved surfaces convex outward. The thickness of the thick portion 2b gradually approaches the thickness of the tube wall 2a as it moves away from the top in the circumferential direction. 2 d of outer peripheral surfaces which form the connection part of the thick part 2b and the tube wall 2a are curved surfaces which connect smoothly with 2d of outer peripheral surfaces in the tube wall 2a.

With such a configuration, the bending rigidity of the main tube 2 is minimized with respect to the axis Y passing through the center of the thick portion 2b and the center of the first lumen 2c, and the axis perpendicular to the axis Y at the center of the first lumen 2c. maximum with respect to X.

As shown in FIG. 4, the second lumen 2e extends from the rear end of the main tube 2 (the left end in FIG. 4) to near the tip of the main tube 2 (the right end in FIG. 4). The rear end of the second lumen 2e is open, while the tip is closed.
An opening 2f that communicates with the inside of the second lumen 2e penetrates an outer peripheral surface 2d of the thick portion 2b surrounded by the fixing balloon 3. As shown in FIG.
The number of openings 2f is not particularly limited as long as it is one or more. In the example shown in FIG. 3, they are formed at two locations separated in the longitudinal direction of the main tube 2 .

The material of the main tube 2 has flexibility. The main tube 2 can bend according to the curvature of the body when inserted into the body.
For example, the material of the main tube 2 may be silicone rubber with a rubber hardness (Shore A) of A70. In this case, the tube wall 2a may have a thickness of 1.25 mm.
In this case, if the inner diameter of the second lumen 2e is 17.5 mm, the maximum thickness of the thick portion 2b may be 1.5 mm or more and 5 mm or less.

As shown in FIG. 4, the fixation balloon 3 is arranged on the outer peripheral surface 2d of the distal end portion of the main tube 2 so as to surround the opening 2f.
The fixation balloon 3 is made of elastic thin elastomer and can be expanded and contracted in the radial direction. The fixation balloon 3 has a cylindrical shape as a whole in an expanded state. The fixation balloon 3 can be folded in the circumferential direction in the contracted state.
Hereinafter, unless otherwise specified, the shape of the fixation balloon 3 in a diameter-expanded state in which tension is not generated will be described.

The fixation balloon 3 has a first cylindrical portion 3a, a first enlarged diameter portion 3b, a second cylindrical portion 3c, a second enlarged diameter portion 3d, and a third cylindrical portion 3e from the rear end to the tip of the fixation balloon 3. , in that order.

The first cylindrical portion 3a has an inner diameter that fits into the outer peripheral surface 2d of the main tube 2 from the outside, and is airtightly fixed to the outer peripheral surface 2d. A fixing method of the first cylindrical portion 3a is not particularly limited as long as airtightness is maintained. For example, the first cylindrical portion 3a may be fixed to the outer peripheral surface 2d by adhesion, heat-sealing, or the like.

The first expanded-diameter portion 3b has a cylindrical shape that is connected to the tip of the first cylindrical portion 3a and extends from the tip of the first cylindrical portion 3a toward the tip of the overtube 1. The diameter of the first enlarged diameter portion 3b gradually increases from the diameter of the first cylindrical portion 3a toward the tip from the rear end of the first enlarged diameter portion 3b.

The second cylindrical portion 3 c has a cylindrical shape that smoothly connects to the tip of the first enlarged diameter portion 3 b and extends from the tip of the first enlarged diameter portion 3 b toward the tip of the overtube 1 . The outer diameter of the second cylindrical portion 3c is a constant value that is smaller than the inner diameter of an indwelling site in the body, such as the intestinal tract, in an enlarged diameter state in which tension is not generated. However, as will be described later, when it is inflated by supplying air, it can be expanded to a diameter larger than the inner diameter of the detention site.
As shown in FIGS. 4 and 6, the second cylindrical portion 3c is arranged substantially concentrically with the first lumen 2c at a position surrounding each opening 2f from the radial outside.

As shown in FIG. 4, the second enlarged diameter portion 3d has a cylindrical shape that connects to the tip of the second cylindrical portion 3c and extends from the tip of the second cylindrical portion 3c toward the tip of the overtube 1. As shown in FIG. The diameter of the second enlarged diameter portion 3d gradually decreases from the diameter of the second enlarged diameter portion 3d toward the tip from the rear end of the first enlarged diameter portion 3b. Therefore, the diameter of the second enlarged diameter portion 3d is gradually increased from the front end to the rear end of the second enlarged diameter portion 3d.

The third cylindrical portion 3e is connected to the tip of the second enlarged diameter portion 3d. Like the first cylindrical portion 3a, the third cylindrical portion 3e has an inner diameter that fits on the outer peripheral surface 2d of the main tube 2 from the outside, and is airtightly fixed to the outer peripheral surface 2d.
In the example shown in FIG. 4 , the tip of the third cylindrical portion 3 e is fixed at a position close to the tip of the main tube 2 .

The material of the fixation balloon 3 is not particularly limited as long as it can be expanded or contracted to a required size by the pressure of air supplied between the main tube 2 and the fixation balloon 3 .
For example, the material of the fixation balloon 3 may be silicone rubber having a rubber hardness (Shore A) of A15 or more and A30 or less. In this case, the thickness of the fixation balloon 3 may be, for example, 0.15 mm or more and 0.3 mm or less.

In the expanded diameter state of the fixation balloon 3, the outer peripheral surface 2d of the main tube 2 and the inner peripheral surfaces of the first expanded diameter portion 3b, the second cylindrical portion 3c, and the second expanded diameter portion 3d of the fixation balloon 3. , communicates with the second lumen 2e through each opening 2f. Since the space S3c is separated from the space S2c formed inside the first lumen 2c by the main tube 2, the space S3c does not communicate with the space S2c.

The distal tip 4 is connected to the distal end of the main tube 2 . The distal tip 4 has flexibility. The distal tip 4 is a cylindrical member coaxial with the first lumen 2c of the main tube 2 as a whole.
The detailed shape of the distal tip 4 will be described with reference to FIG.
FIG. 7 is an enlarged view of F7 in FIG.
The distal tip 4 has a connecting portion 4c, a second tubular portion 4b, and a first tubular portion 4a in this order from the rear end of the distal tip 4 toward the distal end.

The connecting portion 4 c is a substantially circular ring that connects to the main tube 2 . A rear end portion of the connecting portion 4 c is fitted to the outer peripheral surface 2 d of the main tube 2 from the outside and fixed to the front end of the main tube 2 . Therefore, the outer diameter of the connecting portion 4 c is slightly larger than the outer diameter of the outer peripheral surface 2 d of the main tube 2 .
A fixing method of the connecting portion 4c is not particularly limited. For example, the connecting portion 4c may be fixed to the main tube 2 by adhesion, heat welding, or the like.
The second lumen 2e at the distal end of the main tube 2 may be closed by fixing the connecting portion 4c. However, the connecting portion 4c may be fixed to the main tube 2 in a state in which an adhesive or the like is injected into the distal end portion of the second lumen 2e to close the second lumen 2e.

The second pipe portion 4b is a cylindrical body with lower rigidity than the main tube 2. The shape of the second tube portion 4b is not particularly limited as long as the endoscope 11 can be inserted through the inside thereof and the rigidity is lower than that of the connecting portion 4c.

The first pipe portion 4a extends from the tip of the second pipe portion 4b. The first pipe portion 4a is a tubular body having higher rigidity than the second pipe portion 4b, and has a tip opening 4f penetrating through the tip thereof.
The diameter of the tip opening 4f is smaller than that of the second inner peripheral surface 4d and is large enough for the endoscope 11 to pass through. For example, the first tubular portion 4a has an annular shape whose diameter gradually decreases from the rear end toward the tip of the first tubular portion 4a.

The detailed shape and material of the distal tip 4 are not particularly limited as long as they simultaneously satisfy the following formulas (1a) and (1b).

Here, K1 is the rigidity of the first pipe portion 4a, K2 is the rigidity of the second pipe portion 4b, and K3 is the rigidity of the main tube 2. The rigidity referred to here is bending rigidity.

In the example shown in FIG. 7 , the second tube portion 4 b has a cylindrical shape with an inner diameter substantially the same as that of the first lumen 2 c of the main tube 2 and an outer diameter smaller than the outer peripheral surface 2 d of the main tube 2 .
In the example shown in FIG. 7, the first pipe portion 4a is formed thicker than the second pipe portion 4b. A first inner peripheral surface 4e, which is an inner peripheral surface of the first pipe portion 4a, is a curved surface whose diameter gradually decreases from the rear end toward the tip of the first pipe portion 4a.
In the example shown in FIG. 7, the rigidity of the second pipe portion 4b is made lower than the rigidity of the first pipe portion 4a by changing the thickness.

In the example shown in FIG. 7, the thicknesses of the second pipe portion 4b and the first pipe portion 4a are constant, but the second pipe portion 4b and the first pipe portion 4a have different geometrical moments of inertia. may have a cross-sectional shape of For example, at least one of the second pipe portion 4b and the first pipe portion 4a may have a longitudinally extending ridge, groove, or the like.
For example, the second pipe portion 4b may be formed in a bellows shape with lower rigidity than the first pipe portion 4a.

The material of the tip 4 may be silicone resin. For example, the material of the tip 4 may be silicone rubber with a rubber hardness (Shore A) of A40. In this case, for example, the thickness of the second pipe portion 4b may be 1 mm, and the thickness of the first pipe portion 4a may be 2 mm.

As shown in FIG. 4, the grip portion 5 has a tubular portion 5a, a stopper 5b, a first luer connector 5c, a first conduit 5d, a second luer connector 5e, a second conduit 5f, and a cap 5g.
The stopper 5b can be used by the operator to support the rear end of the main tube 2 outside the patient's body and to operate the insertion and removal of the overtube 1 .

The tubular portion 5 a is substantially cylindrical and coaxial with the first lumen 2 c of the main tube 2 . A fitting hole 5h for fitting the outer peripheral surface 2d of the main tube 2 from the outside is formed in the distal end of the tubular portion 5a. The rear end of the main tube 2 is fixed in the fitting hole 5h with the rear end of the main tube 2 inserted therein.
The fixing method of the main tube 2 is not particularly limited as long as it is airtight. For example, the main tube 2 may be fixed to the fitting hole 5h by adhesion, heat sealing, or the like.
An inner peripheral surface 5i, which is a cylindrical surface having the same diameter as the first lumen 2c, extends through the rear end portion of the tubular portion 5a in the longitudinal direction. The tip of the inner peripheral surface 5i is smoothly connected to the first lumen 2c.

A stopper 5b protrudes radially outward from the outer peripheral portion of the tubular portion 5a. The projecting position of the stopper 5b is equal to the position of the rear end of the main tube 2 in the longitudinal direction. The stopper 5b protrudes upward and downward in the drawing. The outer shape of the stopper 5b when viewed in the longitudinal direction is, for example, a substantially elliptical plate elongated vertically in the drawing (see FIG. 1).
The stopper 5b is provided, for example, for the purpose of preventing the portion on the rear end side of the stopper 5b from entering the lumen when the overtube 1 is inserted into the patient's lumen. Therefore, the stopper 5b is formed in a size that cannot be inserted into the lumen. For example, when the overtube 1 is used by inserting it into the large intestine, the stopper 5b is formed larger than the size of the anus. In this case, it is more preferable that the size of the stopper 5b in the longitudinal direction does not fit into a circle with a diameter of 55 mm or less centered on the center of the tubular portion 5a.

The first luer connector 5c is a luer lock type connector. The first luer connector 5c is attached to the outer peripheral portion of the tubular portion 5a on the rear side of the stopper 5b in the grip portion 5. As shown in FIG. A first conduit 5d is formed inside the tubular portion 5a to communicate with the first luer connector 5c and the second lumen 2e of the main tube 2 fixed to the fitting hole 5h.
As shown in FIG. 1, an airflow tube 9 (air supply tube) of an air supply device 10, which will be described later, is detachably connected to the first luer connector 5c.

As shown in FIG. 4, the second luer connector 5e is a luer lock type connector. The second luer connector 5e is attached to the outer peripheral portion of the tubular portion 5a on the side opposite to the first luer connector 5c across the tubular portion 5a. Inside the tubular portion 5a, a second conduit 5f is formed that communicates with the first luer connector 5c and opens to the inner peripheral surface 5i.
For example, the second luer connector 5e can detachably connect a syringe. For example, the friction between the endoscope and the main tube 2 can be reduced by injecting sterilized water or medical lubricant from a syringe through the second luer connector 5e into the first lumen 2c.
In the example shown in FIG. 4, since no syringe is connected, a cap 5g is attached to hermetically close the opening of the second luer connector 5e. Thereby, the second pipeline 5f is closed.

Next, the airtight valve unit 6 will be explained.
FIG. 8 is a schematic cross-sectional view showing an example of an airtight valve unit in the endoscope overtube according to the first embodiment of the present invention. FIG. 9 is a schematic perspective view showing an example of an airtight balloon of an airtight valve unit in the endoscope overtube according to the first embodiment of the present invention.

The airtight valve unit 6 hermetically seals the outer peripheral portion of the endoscope 11 at the rear end portion of the insertion portion I in a state in which the endoscope 11 is inserted through the first lumen 2c of the main tube 2 .
As shown in FIG. 8 , the airtight valve unit 6 has a cylinder frame portion 21 (tubular portion) and an airtight balloon 22 .

The cylinder frame portion 21 is a substantially cylindrical cylinder.
A fitting hole 21c into which the rear end portion of the tubular portion 5a of the grip portion 5 is fitted from the outside is formed in the front end side of the tubular frame portion 21 .
An inner peripheral surface 21a forming a circular hole extending in the longitudinal direction of the grip portion 5 extends to the rear end of the cylindrical frame portion 21 at the bottom portion of the fitting hole 21c on the left side in the drawing. The diameter of the inner peripheral surface 21a is slightly larger than the diameter of the inner peripheral surface 5i of the tubular portion 5a.
A rear end portion of the tubular portion 5a is inserted into the fitting hole 21c, and the rear end of the tubular portion 5a is joined to the fitting hole 21c while being in contact with the hole bottom portion of the fitting hole 21c.

A cylindrical connection port 21 b protrudes from the outer peripheral surface of the cylindrical frame portion 21 .
Inside the connection port 21b, a connection port 21d and a through hole 21e are formed in this order from the outside in the radial direction of the cylindrical frame portion 21 toward the inside.
The connection port 21d is a recess for connecting an operation tube main body 25, which will be described later.
The through hole 21e allows communication between the opening of the operation tube body 25 connected to the connection port 21d and the space inside the inner peripheral surface 21a.

The material of the cylindrical frame portion 21 is not particularly limited. For example, the material of the cylindrical frame portion 21 can be resin, metal, silicone rubber, or the like.

The airtight balloon 22 is a cylindrical member made of the same material as the fixation balloon 3 .
The airtight balloon 22 has a first joint portion 22a, an intermediate portion 22b, and a second joint portion 22c.
The first joint portion 22a and the second joint portion 22c are formed at the leading end and the trailing end of the airtight balloon 22, respectively. The first joint portion 22a and the second joint portion 22c are ring-shaped so that they can be joined to the inner peripheral surface 21a of the tubular frame portion 21 . In the example shown in FIG. 8, the first joint portion 22a and the second joint portion 22c are annular with the same outer diameter, corresponding to the fact that the inner peripheral surface 21a is a cylindrical surface.

The intermediate portion 22b is connected to the rear end of the first joint portion 22a and the front end of the second joint portion 22c, respectively, and connects the first joint portion 22a and the second joint portion 22c over the entire circumference.
The outer diameter of the intermediate portion 22b is at least partially smaller than the outer diameters of the first joint portion 22a and the second joint portion 22c. In this embodiment, the outer diameter of the intermediate portion 22b decreases from the rear end of the first joint portion 22a toward the rear, becomes minimum at the central portion in the axial direction, and extends from the central portion to the second joint portion 22c rearward. increasing as you go. As shown in FIG. 9, the central axes of the first joint portion 22a, the intermediate portion 22b, and the second joint portion 22c are coaxial with each other.

As shown in FIG. 8, the airtight balloon 22 is inserted inside the inner peripheral surface 21a of the cylindrical frame portion 21 and is joined to the inner peripheral surface 21a at a first joint portion 22a and a second joint portion 22c. The axial length of the airtight balloon 22 is not particularly limited, but in the example shown in FIG. 8, it is equivalent to the axial length of the inner peripheral surface 21a.
The bonding method of the airtight balloon 22 is not particularly limited. For example, the airtight balloon 22 may be joined to the inner peripheral surface 21a by gluing.

When the airtight balloon 22 is joined to the inner peripheral surface 21a, a space Sp is formed between the inner peripheral surface 21a and the intermediate portion 22b. The intermediate portion 22b radially covers the through hole 21e. Therefore, the space Sp communicates with the connection port 21d of the connection port 21b through the through hole 21e.

As a material for the airtight balloon 22, an appropriate elastic elastomer is used. For example, a material similar to that of the fixation balloon 3 may be used as the material of the airtight balloon 22 .
When fluid is supplied into the space Sp or sucked out from the space Sp through the connection port 21b, the shape of the intermediate portion 22b changes according to the internal pressure of the space Sp. The fluid supplied to the space Sp may be either gas or liquid as long as it can apply pressure that can change the shape of the intermediate portion 22b.
In this embodiment, gas is supplied to the space Sp. The type of gas is not particularly limited. For example, it is more preferable to use air as the gas in that the intermediate portion 22b can form a state in which the intermediate portion 22b protrudes inward by opening the space Sp to the atmosphere.

When the gas is supplied into the space Sp, the intermediate portion 22b forms a shape that bulges inward of the inner peripheral surface 21a according to the internal pressure of the space Sp. For example, if gas is supplied in a volume larger than the volume of the space Sp when the airtight balloon 22 is attached, the internal pressure of the space Sp rises and the intermediate portion 22b expands.This increases the volume of the space Sp. The inflated intermediate portion 22 b reduces the space radially inside the airtight balloon 22 . Therefore, the inner diameter of the intermediate portion 22b is reduced as a whole while maintaining the smallest inner diameter at the center in the axial direction.
When the gas is sucked out from the space Sp, the intermediate portion 22b expands in diameter according to the decrease in the internal pressure of the space Sp. When the gas becomes less than the volume of the space Sp when the airtight balloon 22 is attached, the intermediate portion 22b is pressed toward the inner peripheral surface 21a. When all the gas is sucked out from the space Sp, the intermediate portion 22b receives atmospheric pressure from the inside of the airtight balloon 22 and expands in diameter, and the intermediate portion 22b sticks to the inner peripheral surface 21a. As a result, inside the airtight balloon 22, a conduit having an inner diameter substantially the same as that of the inner peripheral surface 21a is formed. FIG. 4 shows a state in which the gas in the space Sp is sucked.

As shown in FIG. 4, the airtight valve operating tube 7 has an operating tube main body 25, a pressure adjusting balloon 26, and a cock 27.

The operation tube main body 25 circulates the gas entering and leaving the space Sp. A first end portion 25a of the operation tube main body 25 is connected to the connection port 21b. A pressure adjusting balloon 26 is connected to a second end 25b opposite to the first end 25a.

The pressure adjustment balloon 26 communicates with the space Sp through the operation tube main body 25. The pressure regulation balloon 26 does not expand until the pressure in the space Sp reaches a predetermined value, and expands after reaching the predetermined value. This makes it possible to adjust the pressure in the space Sp. Details of the action of the pressure adjustment balloon 26 in this embodiment will be described together with the operation of the overtube 1 .

The shape and material of the pressure adjustment balloon 26 are not particularly limited as long as the pressure can be adjusted as described later. In the example shown in FIG. 4, the pressure regulation balloon 26 has a substantially cylindrical shape and is made of silicone rubber.

A cock 27 is connected to the pressure adjusting balloon 26 .
The cock 27 is a tubular member through which gas can flow. The cock 27 has a connection port 27a, a valve 27b, and an opening 27c.
The connection port 27a detachably connects a gas moving device such as a syringe or a pump, for example. In the example shown in FIG. 1, the cock 27 is equipped with a syringe 28 as a gas moving device.
As shown in FIG. 4, valve 27b opens to allow gas flow when the gas moving device is connected to port 27a, and closes to allow gas to flow from port 27a when the gas moving device is disconnected from port 27a. Prevent gas outflow.
The opening 27c is opened inside the pressure adjusting balloon 26 and allows the inside of the pressure adjusting balloon 26 and the flow path inside the cock 27 to communicate with each other.

As shown in FIG. 1, the air supply device 10 mainly supplies air for expanding the diameter of the fixation balloon 3 . In this embodiment, the supplied air can also be sucked into the air supply device 10 by appropriately switching the flow path in the air supply device 10 .
The air supply device 10 has an airflow tube 9 that circulates air to the second lumen 2 e of the main tube 2 .
The airflow tube 9 communicates with the internal flow path of the air supply device 10 for supplying air and extends outward from the housing of the air supply device 10 . The airflow tube 9 forms an air flow path between the second lumen 2 e and the internal flow path of the air supply device 10 .
A connector 9 a that is detachably connected to the first luer connector 5 c of the grip portion 5 is provided at the tip of the air flow tube 9 in the extending direction.
When the connector 9a is connected to the first luer connector 5c, the second lumen 2e communicates with the internal flow path of the air supply device 10 through the airflow tube 9.
The inner diameter of the conduit of the airflow tube 9 may be, for example, 2.0 mm or more and 5 mm or less.

The air supply device 10 has a pump for supplying air. The type of pump is not particularly limited. For example, the pump may be an electric pump or a manual pump.
If the pump is an electric pump, it may have a pressure control circuit. A pressure control method is not particularly limited.
The air supply device 10 has a relief valve that expands the air to the outside when the pressure of the supplied air exceeds a certain value so that the supply pressure of the air does not exceed the allowable value of the internal pressure of the fixation balloon 3 .

The air supply device 10 is capable of supplying air through the airflow tube 9 and sucking air from the airflow tube 9 . The configuration for switching between supply and suction is not particularly limited.
For example, the air supply device 10 includes a switching valve that selectively switches between the flow path between the air supply port of the pump and the airflow tube 9 and the flow path between the intake port of the pump and the airflow tube 9, and a switching valve control unit that controls the operation of the switching valve.
For example, the air supply device 10 may have a pump that can switch between air supply and suction at an opening connected to the airflow tube 9 .

Next, operation of the airtight valve unit 6 will be described. In the operation of the overtube 1 and the endoscope 11, when the subject of operation is not limited to the operator, the subject of operation is described as "operator or assistant". Below, "operator or assistant" may be written as "operator, etc.".
FIG. 10 is an operation explanatory view of the airtight valve unit in the endoscope overtube according to the first embodiment of the present invention. 11 is a cross-sectional view taken along line F11-F11 in FIG. In FIG. 11, illustration of the internal structure of the endoscope 11 is omitted for simplification.

As shown in FIG. 10, a syringe 28 is attached to the cock 27 .
When the operator or the like pulls the plunger 28 a of the syringe 28 , the gas in the space Sp is sucked and moves inside the syringe 28 . The inside of the space Sp becomes a negative pressure. As a result, the intermediate portion 22b, as shown in FIG. It expands to a size equivalent to the inner diameter of the first lumen 2c of the mirror 11 . This state is called an open state of the airtight valve unit 6 .

In the open state of the airtight valve unit 6, the inner diameter of the inner portion of the intermediate portion 22b is larger than the outer diameter of the endoscope 11 to which the endoscope cap 13 is attached and which has the grasping device 14 and the channel tube 15. Therefore, when the airtight valve unit 6 is open, the endoscope 11 can be smoothly inserted inside the intermediate portion 22b. When the endoscope 11 is inserted, the endoscope 11 is not in contact with the intermediate portion 22b, or even if it is in contact, only a part of the outer shape is in contact with it. Therefore, the endoscope 11 does not receive insertion resistance from the intermediate portion 22b, or even if it does, the insertion resistance is small.

Similarly, the endoscope 11 can be inserted inside the inner peripheral surface 5i of the grip portion 5 and the first lumen 2c of the main tube 2 with low insertion resistance.
When the distal end of the endoscope 11 reaches the distal opening 4f of the distal tip 4, the endoscope 11 protrudes forward from the distal tip 4 through the distal opening 4f, as shown in FIG.
At this time, since the distal opening 4 f is close along the outer peripheral portion of the endoscope 11 , it is difficult for living tissue, body fluid, etc. in front of the distal tip 4 to enter the distal tip 4 .

As shown in FIG. 10, the operator or the like operates the plunger 28a to move the gas in the syringe 28 to the space Sp after the endoscope cap 13 has passed through the cylindrical frame portion 21 . As a result, the negative pressure in the space Sp is released, and the intermediate portion 22b expands radially inward.
As shown in FIG. 11 , the operator or the like supplies gas to the space Sp until the intermediate portion 22b contacts the entire circumference of the outer peripheral portion of the endoscope 11 . As a result, the gap between the outer peripheral portion of the endoscope 11 and the intermediate portion 22b is closed. This state is called the closed state of the airtight valve unit 6 .
In the closed state, the intermediate portion 22b is in close contact with the entire circumference of the outer peripheral portion of the endoscope 11, so the endoscope 11 is held substantially at the center of the inner peripheral surface 21a. Therefore, in the vicinity of the intermediate portion 22b, only the sliding resistance load with the intermediate portion 22b acts on the endoscope 11. FIG.
If the insertion resistance of the endoscope 11 does not become too large, the operator may press the plunger 28a to form a closed state so that the gas is supplied until the internal pressure of the space Sp becomes higher than the atmospheric pressure. good. In this case, at least the intermediate portion 22b has a tension due to expansion from the natural state.

Here, an example of the relationship between the air supply amount (air supply volume) from the syringe 28 and the internal pressure of the space Sp will be described.
FIG. 12 is a graph showing the relationship between the amount of air supplied from the gas moving device and the internal pressure of the airtight balloon in the endoscope overtube of the first embodiment of the present invention. In FIG. 12, the horizontal axis is the air supply amount [mL], and the vertical axis is the internal pressure [kPa] of the space Sp.
However, FIG. 12 is an example in which the gas supplied from the syringe 28 is air.

As shown in FIG. 12, the airtight balloon 22 is inflated without inflating the pressure regulation balloon 26 until the internal pressure of the space Sp reaches a predetermined value P1. When the internal pressure reaches a predetermined value P1, inflation of the pressure regulation balloon 26 begins. After that, the pressure adjustment balloon 26 is inflated by air supply from the syringe 28, and the increase in the internal pressure of the space Sp is suppressed. As a result, the internal pressure value of the space Sp is maintained within a predetermined range around P1 and prevented from increasing excessively in a certain range of air supply amount until the pressure adjustment balloon 26 reaches the inflation limit.
The overtube 1 is easy to operate because the internal pressure value of the space Sp can be maintained within a predetermined range without the need for the operator to finely operate the syringe 28 .
However, the mechanism for adjusting the pressure inside the space Sp is not limited to the pressure adjustment balloon 26 . For example, instead of the pressure control balloon 26, a control valve that is opened at a predetermined internal pressure to release the air supplied from the syringe 28 may be provided.

Next, the operation of using the overtube 1 according to the present embodiment will be described.
In the following, the endoscope 11 is a colonoscope, and ESD (endoscopic submucosal dissection) is performed in the large intestine by an endoscope system that combines the overtube 1 and the endoscope 11. will be explained with an example.
The length of the insertion portion I of the overtube 1 is about the length from the anus to the treatment site and shorter than the insertion portion of the endoscope 11 .
For example, when inserting the overtube 1 after inserting the endoscope 11, it is more preferable to insert the endoscope 11 close to the treatment site before inserting the overtube 1 into the body. In this case, the insertion portion of the endoscope 11 needs to be able to protrude from the distal end of the overtube 1 to some extent.
For example, it is more preferable that the length of the insertion section I is shorter than that of the insertion section of the endoscope 11 by 50 cm to 70 cm.
For example, if the insertion portion I is 70 cm shorter than the insertion portion of the endoscope 11, and the length from the anus to the treatment site is less than 70 cm, the overtube 1 is placed outside the patient's body and the treatment site is shortened. Only the endoscope 11 can be placed nearby.

The minimum inner diameter of the intermediate portion 22b of the airtight balloon 22 is preferably slightly smaller than the outer diameter of the insertion portion. Here, the minimum inner diameter of the intermediate portion 22b is the minimum inner diameter when the intermediate portion 22b protrudes most toward the center without tension.

13 and 14 are schematic diagrams showing an example of how to use the endoscope overtube according to the first embodiment of the present invention. FIG. 15 is a schematic cross-sectional view illustrating the action of the distal tip in the endoscope overtube according to the first embodiment of the present invention.
FIG. 16 is a schematic diagram showing an example of how to use the endoscope overtube according to the first embodiment of the present invention.
However, in FIGS. 13 to 16, the detailed shapes of the endoscope cap 13, the grasping device 14, the channel tube 15, etc. of the endoscope 11 are omitted for the sake of clarity.

First, the overtube 1 is prepared.
In the prepared overtube 1, the gas in the space S3c inside the fixation balloon 3 is sucked out by the air supply device . Therefore, the fixation balloon 3 is folded and is close to the outer peripheral surface 2 d of the main tube 2 . As a result, the outer diameter of the overtube 1 at the portion where the fixation balloon 3 is provided is reduced to substantially the same diameter as the outer diameter of the main tube 2 where the fixation balloon 3 is not provided. This state is hereinafter referred to as the diameter-reduced state of the fixation balloon 3 .
The prepared overtube 1 is made so that the insertion portion of the endoscope 11 can be inserted into the cylindrical frame portion 21 with low resistance. An example in which the gas supplied to the space Sp is air will be described below.
For example, when the gas supplied to the space Sp is air, the air in the space Sp is sucked to form an open state, or the intermediate portion 22b is protruded in a state where no tension is generated. .
As a result, a substantially cylindrical space is formed inside the cylindrical frame portion 21 in which the endoscope 11 can move forward and backward without substantially resistance.
For example, to set the space Sp to the atmospheric pressure, the valve 27b is opened by attaching the syringe 28 with the plunger 28a removed to the cock 27 . As a result, the space Sp communicates with the outside, and the inside of the space Sp becomes atmospheric pressure. After that, when the syringe 28 is removed from the cock 27, the valve 27b is closed and the space Sp is kept at atmospheric pressure.

After that, the operator inserts the distal end of the endoscope 11 inside the cylindrical frame portion 21 of the overtube 1 . After that, the insertion portion of the endoscope 11 is passed through the inner peripheral surface 5i of the grip portion 5, the first lumen 2c of the main tube 2, and the inside of the distal tip 4, and the insertion portion of the endoscope 11 is inserted into the distal end. It extends from the tip opening 4 f of the tip 4 .

After that, as shown in FIG. 13, the operator places the overtube 1 outside the patient's body, and inserts the insertion portion of the endoscope 11 projecting from the overtube 1 into the large intestine C through the anus. Since the large intestine C is tortuous, the operator inserts the endoscope 11 while confirming the inside of the large intestine C based on the image obtained. After the treatment site Ts appears in the image acquired by the endoscope 11 , the operator stops inserting the endoscope 11 .

Thereafter, as shown in FIG. 14 , the operator inserts the overtube 1 into the large intestine C from the anus along the insertion portion of the endoscope 11 . At this time, the intermediate portion 22 b of the airtight valve unit 6 (not shown) is brought into close contact with the outer peripheral portion of the endoscope 11 .
For example, when ESD is performed using only a treatment tool that is inserted into the treatment tool channel 12b of the endoscope 11, the endoscope cap 13 can be removed from the endoscope 11 together with the grasping device 14 and the channel tube 15. .
In this case, if the minimum inner diameter of the intermediate portion 22b of the airtight balloon 22 is equal to or smaller than the outer diameter of the main tube 2 of the endoscope 11, the intermediate portion 22b may be partially displaced from the outer circumference of the main tube 2 simply by inserting the endoscope. It comes into contact with the surface over the entire circumference, closing the gap between the overtube 1 and the endoscope 11 . Furthermore, unless the difference between the minimum inner diameter of the intermediate portion 22b and the outer diameter of the main tube 2 becomes too large, the contact area between the intermediate portion 22b and the outer peripheral surface of the main tube 2 does not become too large. and the overtube 1 are reduced in relative movement.
In this case, if the space Sp of the airtight balloon 22 is at atmospheric pressure, it is not necessary to supply more air into the space Sp.

However, ESD may be performed using the grasping device 14 in addition to the treatment tool inserted through the treatment tool channel 12b. For example, an endoscope cap 13 is attached to the distal end portion 12 of the endoscope 11 , and a grasping device 14 and a channel tube 15 are arranged along the longitudinal direction of the main tube 2 .
In this case, in the endoscope 11, the outer diameter of the portion to which the endoscope cap 13 is attached becomes large, so there is a possibility that it will be difficult to insert it into the overtube 1 when the intermediate portion 22b protrudes.
According to the present embodiment, the operator or the like attaches the syringe 28 to the cock 27 and sucks air out of the space Sp, thereby opening the intermediate portion 22b. As a result, the portion to which the endoscope cap 13 is attached can be smoothly inserted into the cylindrical frame portion 21 .
After the endoscope cap 13 is inserted, the operator or the like operates the plunger 28a of the syringe 28 attached to the cock 27 to supply air to the space Sp, thereby increasing the internal pressure of the space Sp.
As a result, the intermediate portion 22b is in close contact with the side surface of the insertion portion of the endoscope 11 on which the channel tube 15 is arranged on the outer peripheral surface (see FIG. 11), and the inside of the cylindrical frame portion 21 and the endoscope 11 are inserted. The gap between the side of the part and the part is closed.
At this time, since the pressure adjusting balloon 26 is provided in the air flow path, even if the amount of air supplied by the plunger 28a increases to some extent, the internal pressure of the space Sp is close to the predetermined value P1 as shown in FIG. value is kept. As a result, the internal pressure of the space Sp is regulated, so even if the overtube 1 and the endoscope 11 move relative to each other, the sliding resistance does not exceed a certain value. As a result, the overtube 1 can be smoothly inserted while the airtightness of the airtight valve unit 6 is maintained.

As shown in FIG. 14, the large intestine C is an organ with many bends. When a conventional overtube moves along a bent endoscope, the overtube, which cannot follow the bend, tends to deviate from the central axis of the endoscope. In this case, since a large gap is formed between the opening of the overtube and the side surface of the endoscope, it is known that the inner wall of the large intestine C may be caught in the gap.

As shown in FIG. 15, according to the overtube 1 according to this embodiment, a distal tip 4 is provided at the distal end.
The front end of the front tip 4 is formed with a first tube portion 4a whose diameter is reduced from the rear end toward the front end. Therefore, since the tip opening 4f is close to the outer peripheral surface of the endoscope 11, the gap itself between the outer peripheral surface of the endoscope 11 is reduced.
Furthermore, a second pipe portion 4b having lower rigidity than the first pipe portion 4a extends to the rear end of the first pipe portion 4a.
Therefore, when the distal tip 4 passes through the bent portion of the endoscope 11 that is bent following the shape of the large intestine C, the second tube portion 4b deforms before the first tube portion 4a. As a result, the shape of the first tube portion 4 a , particularly the tip opening 4 f , is maintained in a shape close to the outer peripheral surface of the endoscope 11 . That is, by suppressing the deformation of the tip opening 4f, the gap between the tip opening 4f and the side surface of the endoscope 11 can be prevented from being excessively expanded outside the bend of the endoscope 11. FIG. Therefore, when the overtube 1 is inserted into the large intestine C, it is possible to prevent the inner wall of the large intestine C from being caught in the gap between the overtube 1 and the outer peripheral surface of the endoscope 11 .

In the example shown in FIG. 13, since the treatment site Ts is located near the anus, the overtube 1 is positioned outside the body when the endoscope 11 is stopped.
If the treatment site Ts is located far from the anus, the operator may insert the overtube 1 into the large intestine C before the distal end 12 of the endoscope 11 reaches the treatment site Ts. In this case, the operator alternately repeats advancing the endoscope 11 and advancing the overtube 1 while confirming the position of the distal end portion 12 on the image of the endoscope 11, so that the distal end portion 12 reaches the treatment site Ts. You can move closer to

When the tip of the overtube 1 reaches the vicinity of the tip 12 of the endoscope 11 placed near the treatment site Ts, the operator operates the air supply device 10 to remove the airflow tube 9 and the second lumen 2e. Air is supplied to the fixation balloon 3 via to inflate the fixation balloon 3 .
As shown in FIG. 16, when the fixation balloon 3 is sufficiently inflated, the fixation balloon 3 comes into contact with the inner wall of the large intestine C. As shown in FIG. As a result, the overtube 1 is fixed to the extent that it does not easily move relative to the large intestine C. As shown in FIG.

The operator uses a treatment tool protruding from the endoscope 11 to perform ESD on the treatment site Ts. When the endoscope cap 13 is attached, the grasping device 14 inserted through the channel tube 15 can lift and hold the mucous membrane at the treatment site Ts.
Thereafter, a high-frequency knife or the like protruding from the treatment instrument channel 12b of the endoscope 11 can be used to exfoliate the submucosal layer under the tumor at the treatment site Ts.
During such ESD treatment, liquid, gas, etc. in the large intestine C may enter the overtube 1 from the distal end of the overtube 1 .
In this embodiment, as shown in FIG. 10, in the cylindrical frame portion 21, the airtight balloon 22 closes the gap between the outer peripheral surface of the endoscope 11 and the channel tube 15 and the cylindrical frame portion 21, so that airtightness is achieved. and liquid-tight. This prevents liquid, gas, etc. in the large intestine C from leaking from the cylinder frame portion 21 .

After completing all necessary treatment in ESD, the operator operates the air supply device 10 to suck out the air from the fixation balloon 3 and reduce the diameter of the fixation balloon 3 . After that, the operator pulls out the endoscope 11 and the channel tube 15 from the anus.
This completes the ESD using the overtube 1 .

As described above, the overtube 1 according to the present embodiment includes the airtight balloon 22 in which the intermediate portion 22b protrudes from the inner surface of the cylindrical frame portion 21. Therefore, the overtube 1 can be placed between the endoscope or the like inserted with a small gas supply amount. airtightness and liquidtightness can be ensured.
The insertion portion of the endoscope 11 for the large intestine described above is longer than that of the endoscope for the upper gastrointestinal tract.
Furthermore, since the large intestine is meandering in a complicated manner, when the treatment site is located in the ascending colon, a plurality of strongly curved sites may occur before reaching the treatment site. In this case, the overtube 1 is also bent strongly like the endoscope 11, and the frictional resistance when the endoscope 11 is advanced and retracted with respect to the overtube 1 is much larger than that of the endoscope for the upper gastrointestinal tract.

In such a situation, if the friction between the airtight balloon 22 for ensuring airtightness and liquidtightness and the endoscope 11 increases, it becomes difficult to smoothly advance and retract the endoscope 11 .
The overtube 1 according to the present embodiment can ensure airtightness and liquidtightness with the inserted endoscope 11 with a small amount of gas supply, and by setting appropriate dimensions, it can ensure airtightness and liquidtightness without gas supply. is also possible.

The difficulty of ESD in colon C is higher than ESD in the stomach. The above method of stabilizing the position of the endoscope 11 in the large intestine C using the overtube 1 and combining the endoscope cap 13 is effective in simplifying ESD in the large intestine C. FIG.
On the other hand, if the shape and dimensions of the airtight balloon 22 are set according to the outer diameter when the endoscope cap 13 is attached, the distance between the airtight balloon 22 and the insertion portion of the endoscope 11 after the distal end portion 12 passes through the base is reduced. the gap becomes larger. As a result, the amount of gas required to close the gap increases, the internal pressure of the airtight balloon 22 also increases, and the friction between the endoscope 11 and the airtight balloon 22 increases.
The airtight balloon 22 according to the present embodiment can bring the intermediate portion 22b into close contact with the inner surface of the cylindrical frame portion 21 by applying a negative pressure to the space Sp. Therefore, regardless of the initial shape of the intermediate portion 22b, the distal end portion 12 with the endoscope cap 13 attached can be easily passed through. Furthermore, by releasing the negative pressure after passing through the endoscope cap 13, even if the channel tube 15 is arranged on the outer peripheral portion and the non-circular cross-sectional shape is formed, airtightness and liquidtightness can be achieved with a small amount of gas supply. can be ensured.

As described above, according to the overtube 1 according to the first embodiment, it is possible to provide an endoscope overtube that reduces the burden on a patient and allows smooth operation of the endoscope. .

The first embodiment described above may be implemented with various modifications.
1st Embodiment demonstrated that the air supply device 10 insufflates air. However, the air-supplying device 10 may be provided with a gas supply source different from air, so that instead of air, a gas different from air may be supplied to the fixation balloon 3 .

In the first embodiment, the airtight valve unit 6 is in the open state when the endoscope 11 with the endoscope cap 13 attached is inserted. However, the inner diameter of the intermediate portion 22b may be appropriately adjusted according to the outer diameter and outer shape of the endoscope 11 through which the airtight valve unit 6 is inserted. For example, if the endoscope 11 can be inserted even when the airtight valve unit 6 is not in the open state and the intermediate portion 22b is swollen inward, the endoscope 11 can be inserted without opening the airtight valve unit 6. may be inserted.

Although the operation tube main body 25 is connected to the connection port 21b in the first embodiment, the operation tube main body 25 may be detachably connected to the connection port 21b.

The shape of the intermediate portion 22b of the airtight balloon 22 in the first embodiment is an example, and is not limited to the shape described above. For example, the intermediate portion 22b may have two or more protrusions that protrude radially inward in the axial direction.
For example, the inner peripheral surface of the airtight balloon 22 may be coated with a hydrophilic coating.

The airtight valve unit 6 in the first embodiment has been described as an example in which the pressure regulation balloon 26 regulates the internal pressure of the space Sp. However, the mechanism for adjusting the internal pressure of the space Sp is not limited to the pressure adjustment balloon 26. For example, instead of the pressure regulation balloon 26, a relief valve may be provided that releases air to the outside when the pressure exceeds a predetermined value.

In the first embodiment, since the thicknesses of the first tube portion 4a and the second tube portion 4b in the tip 4 are different from each other, the rigidity of the first tube portion 4a and the thickness of the second tube portion 4b are different. An example in which the stiffness is different has been described. The configuration is not limited to this as long as the configurations have different rigidity.
For example, by adopting a bellows structure as the second pipe portion 4b, the rigidity of the thick portion 2b may be reduced from that of the first pipe portion 4a.
For example, even if the thicknesses of the first pipe portion 4a and the second pipe portion 4b are the same, the rigidity can be made different by making the rigidity of each material of the first pipe portion 4a and the second pipe portion 4b different. may

The tip 4 in the first embodiment may satisfy the following formula (1c) in addition to the formulas (1a) and (1b).

In this case, since the rigidity K3 of the first tube portion 4a is greater than the rigidity K1 of the main tube 2, the main tube 2 does not buckle when the overtube 1 is pushed into the large intestine C using the endoscope 11 as a guide. can be suppressed.

In the first embodiment, the distal tip 4 is fixed to the distal end of the main tube 2. However, tip 4 may be shaped from the same material as main tube 2 .

In the first embodiment, the pressure adjustment balloon 26 is provided at the second end 25b of the operation tube main body 25. However, the pressure regulating balloon 26 may be provided between the first end 25a and the second end of the channel tube 15 .

In the first embodiment, an example in which the airflow tube 9 of the air supply device 10 is connected to the first luer connector 5c has been described. However, an appropriate connecting tube may be interposed between the first luer connector 5c and the airflow tube 9.

As described above, the first lumen 2c is an example of a main lumen through which an endoscope is inserted. The second lumen 2e is an example of an air supply lumen through which gas flows. The main tube 2 is an example of a tube body. The cylindrical frame portion 21 is an example of a tubular portion that communicates with the main lumen at the rear end portion of the tube body.
The fixation balloon 3 is an example of a fixation balloon that is provided on the outer peripheral surface of the distal end of the tube body, expandable outward from the outer peripheral surface, and contractible toward the outer peripheral surface.
Insufflation device 10 is an example of an insufflation device that delivers gas to an insufflation lumen.
The airtight valve unit 6 has a tubular portion that communicates with the main lumen at the rear end of the tube body, and the gap between the endoscope inserted into the main lumen through the tubular portion and the inner peripheral surface of the tubular portion. This is an example of an airtight valve unit that closes the

[Second embodiment]
An endoscope overtube according to a second embodiment of the present invention will be described.
FIG. 17 is a schematic perspective view showing an example of the endoscope overtube according to the second embodiment of the present invention.

An overtube 101 shown in FIG. 17 is an example of an endoscope overtube according to this embodiment.
The overtube 101 has a main tube 102 (tube body) and an air supply device 110 instead of the main tube 2 and air supply device 10 of the overtube 1 according to the first embodiment. The following description will focus on the differences from the first embodiment.

18 is a cross-sectional view taken along line F19-F19 in FIG. 17. FIG. 19 is an enlarged view of the F19 portion in FIG. 18. FIG.
As shown in FIG. 18, the main tube 102 in this embodiment further includes a third lumen 102g (dummy lumen).
Hereinafter, in the description of the main tube 102, in the cross section orthogonal to the longitudinal direction of the main tube 2, the direction along the circular inner peripheral surface of the first lumen 2c is the circumferential direction, and the direction along the circular inner peripheral surface is orthogonal to the circumferential direction. A direction along the diameter of the peripheral surface is called a radial direction. In the radial direction, the direction toward the center of the first lumen 2c may be referred to as the radial inner side, and the direction away from the center may be referred to as the radial outer side.

The third lumen 102g extends through the main tube 102 in the longitudinal direction. However, the third lumen 102g is a dummy hole formed for the purpose of adjusting the rigidity of the thick portion 2b. Since no fluid flows inside the third lumen 102g, a tube for flowing fluid is not connected to the third lumen 102g.
In the present embodiment, the opening at the distal end of the third lumen 102g in the longitudinal direction is closed by the connecting portion with the distal tip 4. As shown in FIG. The opening at the rear end in the longitudinal direction of the third lumen 102g is closed by a connecting portion with the grip portion 5. As shown in FIG.

The third lumen 102g is formed at a position close to the second lumen 2e in the thick portion 2b. The third lumen 102g extends parallel to the second lumen 2e.
The number of third lumens 102g is not particularly limited. In the example shown in FIG. 18, they are formed at two locations facing each other in the circumferential direction with the second lumen 2e interposed therebetween.
In this case, since the third lumens 102g are formed near both sides of the second lumen 2e in the circumferential direction, even if an external force acts on any end of the thick portion 2b in the circumferential direction, the external force is applied to the second lumen 2e. Since it becomes difficult to be transmitted to the lumen 2e, the cross-sectional shape of the second lumen 2e is easily maintained.

The cross-sectional shape of each third lumen 102g in the direction perpendicular to the longitudinal direction of the main tube 102 (hereinafter simply referred to as the cross-sectional shape) should be a shape that can reduce the rigidity of the thick portion 2b at a location away from the second lumen 2e. is not particularly limited.
The cross-sectional shape of each third lumen 102g may be different from each other.
In the example shown in FIG. 18, each third lumen 102g is formed in a line-symmetrical position and shape with respect to the axis Y passing through the center of the second lumen 2e.

For example, the cross-sectional shape of the third lumen 102g may be circular, elliptical, oval, polygonal, or the like. If the third lumen 102g is such a hole, the substantial thickness of the thick portion 2b in which the third lumen 102g is formed is reduced. 102g becomes easily crushed and its rigidity decreases.

For example, in the example shown in FIG. 18, the cross-sectional shape of each third lumen 102g is an oval that is elongated in the circumferential direction.
An example of the relative positional relationship between the second lumen 2e and each third lumen 102g will be described with reference to FIG.
Each third lumen 102g is formed at a position closer to the first lumen 2c in the radial direction. The distance between the inner peripheral surface of the third lumen 102g closer to the first lumen 2c and the inner peripheral surface of the first lumen 2c is t2. Assuming that the thickness of the tube wall 2a is t0, t2 may be half or less of t0.
The distance between the radially outer inner peripheral surface of the third lumen 102g and the outer peripheral surface of the thick portion 2b is not particularly limited, but is longer than t2 in the example shown in FIG. Therefore, the third lumen 102g is formed closer to the first lumen 2c than the center of the thick portion 2b in the radial direction.

On the other hand, the distance between the inner peripheral surface of the second lumen 2e closer to the first lumen 2c and the inner peripheral surface of the first lumen 2c is t1, which is longer than t2.
The distance between the radially outer inner peripheral surface of the second lumen 2e and the outer peripheral surface of the thick portion 2b is t3, which is less than or equal to t1. Therefore, the second lumen 2e is formed radially at the center of the thick portion 2b or slightly radially outward.

The distance between the inner peripheral surface of the third lumen 102g and the inner peripheral surface of the second lumen 2e is d1. d1 is more preferably longer than t2, and is t1 or more in the example shown in FIG.

For example, the material of the main tube 102 is silicone rubber with a rubber hardness (Shore A) of A60 to A80, the inner diameter of the first lumen 2c is 13.8 mm, t0 is 1.2 mm, and the maximum thickness of the thick portion 2b is In the case of 3.1 mm, the diameter of the second lumen 2e is 1.9 mm, t1 is 0.7 mm, and t3 is 0.3 mm.
t2 is 0.5 mm, the circumferential length of the third lumen 102g is 1.54 mm or more and 2 mm or less, the radial width of the third lumen 102g is 0.7 mm, and d1 is 1.3 mm.

According to such a configuration, the first region R1 and the second region R2 are formed side by side in the circumferential direction in the thick portion 2b.
The first region R1 is a region including the second lumen 2e and sandwiched between the third lumens 102g in the circumferential direction.
The second region R2 is formed in the range of the length of the third lumen 102g in the circumferential direction, and is a region with reduced rigidity compared to the first region R1. The second region R2 has a lower rigidity than the tube wall 2a.

Next, the air supply device 110 will be described.
FIG. 24 is a block diagram showing an example of an air supply device in the endoscope overtube according to the second embodiment of the present invention. FIG. 21 is a block diagram showing the flow of the air supply device in the endoscope overtube according to the second embodiment of the present invention during inhalation.

As shown in FIG. 24 , the air supply device 110 has an air supply mechanism 111 , a pressure gauge 112 and a relief valve 113 .
The air supply device 110 has a connection tube 110a to which the airflow tube 9 is connected. The connection pipe 110a allows the air flow path in the airflow tube 9 and the air flow path in the air supply device 110 to communicate with each other.

The air supply mechanism 111 has a pump 111a, a first check valve 111b, a second check valve 111c, a first channel switching portion 111d, a second channel switching portion 111e, and an opening 111f.
The pump 111 a forms an air flow in the conduit inside the air supply mechanism 111 . The type of pump 111a is not particularly limited. For example, the pump 111a may be an electric pump or a manual pump. Examples of manual pumps include rubber bulb pumps, diaphragm pumps, corrugated tube pumps, syringe pumps, and the like.

The first check valve 111b and the second check valve 111c are provided at both ends of the air supply passage pa that is supplied by the pump 111a, and restrict the flow of air in one direction at both ends of the air supply passage pa. do. As a result, a flow from the second check valve 111c to the first check valve 111b is formed in the air supply path pa.
The first check valve 111b and the second check valve 111c are divided into a pipeline pb between which the first pipeline switching section 111d is arranged and a pipeline pc between which the second pipeline switching section 111e is arranged. and are connected to each other through .
The first check valve 111b allows the air in the air supply path pa to flow toward the pipelines pb and pc, and blocks the flow of air from the pipelines pb and pc to the air supply path pa.
The second check valve 111c allows the air flowing through the conduits pb and pc to pass toward the air conduit pa, and blocks the flow of air from the air conduit pa to the conduits pb and pc.

A pipeline pd communicating with the connection pipe 110a is connected to the first pipeline switching portion 111d. The first duct switching unit 111d has a duct in which the duct pb communicates with the duct pd and does not communicate with the second check valve 111c, and a second check valve 111c in which the duct pb does not communicate with the duct pd. To selectively switch between a communicating conduit and a duct.
For example, a switching device such as a channel switching valve may be used as the first channel switching unit 111d. If the pipelines connected to each other can be manually switched, it is not necessary to use a switching device as the first pipeline switching unit 111d.
The second channel switching portion 111 e communicates with an opening portion 111 f that opens air to the outside of the air supply mechanism 111 . The second duct switching unit 111e has a duct in which the duct pc communicates with the second check valve 111c and does not communicate with the first check valve 111b, and a duct in which the duct pc does not communicate with the second check valve 111c. 1 check valve 111b and a conduit communicating with the check valve 111b are selectively switched.
For example, a switching device such as a channel switching valve may be used as the second channel switching unit 111e. If the pipelines connected to each other can be manually switched, it is not necessary to use a switching device as the second pipeline switching unit 111e.

As shown in FIG. 24, the pipeline pd communicates with the first check valve 111b through the first pipeline switching portion 111d, and the pipeline pc communicates with the second check valve 111c through the second pipeline switching portion 111e. When the state is formed, air is sucked from the opening 111f by the air supply of the pump 111a, and an air flow path is formed in which the air is supplied from the conduit pd through the connecting tube 110a (see the solid line arrow). .
As shown in FIG. 21, the pipeline pd communicates with the second check valve 111c through the first pipeline switching portion 111d, and the pipeline pc communicates with the first check valve 111b through the second pipeline switching portion 111e. In the state, air is sucked from the pipeline pd via the connection tube 110a by the air supply of the pump 111a, and an air flow path is formed through which the air is supplied from the opening 111f (see the dashed arrow).

The pressure gauge 112 and the relief valve 113 are provided in this order in the pipeline pd from the first pipeline switching portion 111d to the connection pipe 110a.
A pressure gauge 112 measures the air pressure in the pipeline pd and displays the magnitude of the pressure. The pressure gauge 112 may display the magnitude of the pressure numerically, but the display method is not limited to numerical display. For example, the pressure display on the pressure gauge 112 may visibly display the absolute value of the pressure or the amount of relative deviation from the reference value.

The relief valve 113 discharges the air flowing through the pipeline pd to the outside when the pressure of the air in the pipeline pd exceeds a predetermined allowable pressure value. As a result, the pressure of the air in the pipeline pd is kept below the allowable pressure value.
The allowable pressure value is set to a value that does not excessively inflate the fixation balloon 3 communicating with the duct pd via the airflow tube 9 and the second lumen 2e. The allowable size of the fixation balloon 3 is predetermined according to the lumen into which the overtube 101 is inserted.

According to the air supply device 110, since it has the first channel switching portion 111d and the second channel switching portion 111e, the pump 111a for supplying air in one direction is used to supply air to the airflow tube 9 and to the airflow tube. Intake from 9 can be selectively switched. In the case of air supply, the opening 111f functions as an intake port for sucking air from the outside. In the case of intake, the opening 111f functions as an exhaust port for discharging the intake air to the outside.
Insufflation device 110 has pressure gauge 112 . As a result, the operator can expand and contract the fixation balloon 3 while confirming whether the pressure of the air supplied to the fixation balloon 3 is appropriate.
Insufflation device 110 has a relief valve 113 . As a result, even if the operator performs an air supply operation that exceeds the permissible pressure value, the increase in pressure of the fixation balloon 3 can be suppressed to the permissible value or less.
The main tube 102 is provided with an air supply device 110 so that the operator can perform treatment smoothly.

Next, the operation of the overtube 101 will be described, focusing on the differences from the first embodiment.
According to the overtube 101 according to this embodiment, the air inside the fixation balloon 3 is supplied and sucked by the air supply device 110 instead of the air supply device 10 . Therefore, the overtube 101 can be used for various treatments and surgeries using the endoscope 11 by inserting and fixing it inside the patient's body in the same manner as the overtube 1 according to the first embodiment.
Especially in this embodiment, a main tube 102 is used instead of the main tube 2 . The action of the present embodiment will be described below, centering on the action of the main tube 102 .

As with the overtube 1, the overtube 101 may be used by being inserted into a lumen having a bend in the patient's body.
For example, when the main tube 2 shown in FIG. Since it bends according to its shape, a bending load acts on the main tube 2 passing through the bent portion.
When the main tube 2 is bent at a large bending angle, it may not be possible to maintain the cross-sectional shape as shown in FIG. For example, the tube wall 2a may undergo radial crushing deformation. In this case, since the endoscope 11 is inserted into the first lumen 2c, a cross-sectional area approximately equal to the outer diameter of the endoscope 11 is secured.
However, if the second lumen 2e is collapsed, the supply of air to the fixation balloon 3 will be interrupted, which may hinder expansion and contraction of the fixation balloon 3 .

The present inventors have extensively studied how the main tube 2 collapses, and found that when the main tube 2 is bent, the main tube 2 rotates so that the axis Y shown in FIG. The inventors have found that it is easy to collapse toward the axis Y, and have arrived at the present invention.

As shown in FIG. 18, the flexural rigidity of the main tube 102, like the main tube 2, is minimized with respect to the axis Y passing through the center of the thick portion 2b and the center of the first lumen 2c. with respect to the axis X perpendicular to the axis Y at .
In this case, when subjected to bending with the axis X as the neutral plane of bending, it should collapse in the direction of arrow f2, but the bending rigidity around the axis X is greater than the bending rigidity around the axis Y, so , the work required to bend about the axis X is also large. On the other hand, the main tube 102 is long and is inserted in a state in which there is little restriction from the lumen and the endoscope 11 . A portion of the main tube 102 is readily rotatable about its central longitudinal axis. As a result, when subjected to bending about the axis X, the main tube 102 rotates in a direction that is easier to bend, and the neutral plane of the bending gradually approaches the axis Y. As shown in FIG.

FIG. 22 is a schematic perspective view showing a bent state of the endoscope overtube according to the second embodiment of the present invention. 23 is a cross-sectional view taken along line F23-F23 in FIG. 22. FIG.
FIG. 22 shows how the main tube 102 rotates and the thick portion 2b moves along the neutral plane of the bending when it is bent as indicated by the hollow arrow.
Inside the bend, the tube wall 2a is kinked to produce a large dent.
In this way, when the main tube 102 rotates, the rigidity of the thick portion 2b has little effect on bending deformation, so the main tube 102 can be easily bent with a low load.
In order to suppress the deformation of the cross-sectional shape of the second lumen 2e in the main tube 102 that can be bent in this way, the second lumen 2e should be made difficult to deform when collapsed in the direction of the arrow f1.

FIG. 23 shows an example of a cross section in the vicinity of the second lumen 2e when the tube wall 2a is thus collapsed.
In this embodiment, third lumens 102g are formed on both circumferential sides of the second lumen 2e. When the tube wall 2a collapses in a direction approaching the axis Y, stress concentrates on the portion where the stiffness is lowered by the third lumen 102g. As a result, the third lumen 102g is radially crushed, and the tube wall 2a is bent around the third lumen 102g. For example, a bent groove Cr extending radially outward is formed in the inner peripheral surface of the first lumen 2c facing the third lumen 102g.
In this way, the strain due to the external bending force is absorbed by the deformation of the thick portion 2b around the third lumen 102g. As a result, the stress around the second lumen 2e is alleviated compared to the case where the second region R2 having the third lumen 102g and the low rigidity is not present, so the deformation of the second lumen 2e is suppressed. be done.
Therefore, even if the main tube 102 is bent inside the lumen, the second lumen 2e will not be crushed, making it difficult for the air to flow, and the duct will not be closed.
As a result, even if the main tube 102 is inserted into a lumen having a bent portion, the operator can expand and contract the fixation balloon 3 without any trouble.
For example, it is possible to prevent the fixation position of the overtube 101 from becoming unstable because the fixation balloon 3 cannot be expanded to an appropriate outer diameter. Thereby, surgery using the endoscope 11 can be performed smoothly.
For example, it is possible to prevent the diameter of the fixation balloon 3 from being sufficiently reduced during insertion and withdrawal, thereby preventing the patient from being burdened during insertion and withdrawal.

As described above, the overtube 101 according to the second embodiment includes the main tube 102 and the air supply device 110 instead of the main tube 2 and the air supply device 10 of the overtube 1 according to the first embodiment. Similar to overtube 1, except that it has Therefore, as in the first embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this embodiment, since the main tube 102 is provided, even if the main tube 102 is inserted into a lumen having a bend, the operator can expand and contract the fixation balloon 3 without any trouble.

The tube wall 2 a is an example of a constant thickness portion having a constant thickness in the circumferential direction of the main tube 102 .
The thick portion 2b is an example of a thick portion in which an air supply lumen is formed and the thickness defined by the distance between the outer peripheral surface and the inner peripheral surface in the radial direction is larger than the thickness of the constant thickness portion. .
The main tube 102 is an example of a tube body having a constant thickness portion and a thick portion.
The first region R1 is an example of a first region that is formed in the thick portion and includes an air supply lumen. The second region R2 is an example of a second region that is adjacent to the first region in the circumferential direction and has lower rigidity than both the first region and the constant thickness portion.
The third lumen 102g is formed in the second region, extends in the axial direction along the extending direction of the air supply lumen, and is a dummy lumen that is a hole that cannot supply air to the fixation balloon and cannot inhale from the fixation balloon. For example.
In the thick portion 2b of the main tube 102, the minimum thickness in the radial direction of the portion sandwiched between the dummy lumen and the main lumen is greater than the minimum thickness in the radial direction of the portion sandwiched between the air supply lumen and the main lumen. too thin.
Airflow tube 9 is an example of an air supply tube extending from air supply device 110 .
The second lumen 2e communicates with the air supply tube, and the third lumen 102g does not communicate with the air supply tube.

The second embodiment described above may be implemented with various modifications.
For example, the main tube used for the overtube 101 is not limited to the main tube 102 . For example, in the main tube 102, the second region R2 is formed by providing the third lumen 102g, but the method of forming the second region R2 is not limited to this.
FIG. 24 is a schematic cross-sectional view showing a main part of a main tube that can be used for the endoscope overtube according to the second embodiment of the present invention.

A main tube 102A (tube body) shown in FIG. 24 can be used in place of the main tube 102 in the overtube 101. As shown in FIG.
The main tube 102A is formed with a groove portion 102h instead of the third lumen 102g of the main tube 102. As shown in FIG.
In the following, the points different from the second embodiment will be mainly described.

The groove portion 102h is a V-shaped groove extending radially outward from the inner peripheral surface of the first lumen 2c. The groove width in the circumferential direction of the groove portion 102h decreases radially outward from the inner peripheral surface of the first lumen 2c. The groove portion 102h has a similar cross-sectional shape extending in the longitudinal direction of the main tube 102A.
The groove portion 102h forms a thickness change portion Tv in which the thickness of the thick portion 2b gradually decreases in the circumferential direction, passes through a minimum value, and then increases. The minimum thickness of the thickness change portion Tv is the distance t4 from the groove bottom of the groove portion 102h to the outer peripheral surface 2d. t4 is shorter than t0.
The positions of the grooves 102h may differ in distance from the second lumen 2e, but are symmetrical about the axis Y in the example shown in FIG.
The length in the circumferential direction between the position of the groove portion 102h in the first lumen 2c and the inner peripheral surface of the second lumen 2e is d2. d2 is more preferably greater than or equal to t1.

According to such a configuration, the second lumen 2e is sandwiched between the grooves 102h on both sides in the circumferential direction. Thereby, a first region R1A and a second region R2A are formed in the thick portion 2b.
The first region R1A is a region that includes the second lumen 2e and is sandwiched between two thickness change portions in the circumferential direction.
The second region R2A is formed in the range of the maximum groove width of the groove portion 102h in the circumferential direction, and is a region with reduced rigidity compared to the first region R1A. The second region R2A has a lower rigidity than the tube wall 2a.

The action of the main tube 102A will be described.
25 is a schematic cross-sectional view showing a bent state of the main tube shown in FIG. 24. FIG.
Similar to the main tube 102, the case where the main tube 102A receives bending and collapses toward the axis Y will be described.
As shown in FIG. 25, when the tube wall 2a collapses toward the axis Y, the groove width of each groove 102h is reduced. In the example shown in FIG. 25, the inner surfaces of the grooves 102h are in contact with each other.
Each tube wall 2a adjacent to the groove 102h bends around the groove bottom of the groove 102h under a light load until the groove 102h is closed. Therefore, the groove portion 102h functions as a hinge for rotating the tube wall 2a.
The stress in the vicinity of each groove 102h hardly increases until the groove inner surfaces of the grooves 102h contact each other.
Therefore, deformation in the vicinity of the second lumen 2e can be suppressed by appropriately setting the groove angle of the groove portion 102h according to the amount of collapse of the tube wall 2a.

As described above, the main tube 102A has the groove portion 102h instead of the third lumen 102g, thereby forming the second region R2A with low rigidity like the second region R2. As a result, the stress around the second lumen 2e is alleviated compared to the case where the second region R2A having the groove portion 102h and the low rigidity is not present, so the deformation of the second lumen 2e is suppressed. .
As a result, the main tube 102A has the same action as the main tube 102 does.

In the description of the second embodiment, an example in which the third lumen 102g is provided in the thick portion 2b has been described. However, the third lumen 102g may be provided in the region spanning both the tube wall 2a and the thick portion 2b, or in the region of the tube wall 2a, provided that the rigidity in the second region R2 is not excessively reduced. . The same applies to the groove portion 102h of the modified example.

In the description of the second embodiment, an example in which the second regions R2 are formed on both sides of the first region R1 in the circumferential direction has been described. However, even if the number of the second regions R2 is one, the number of the second regions R2 may be one if the deformation of the second lumen 2e is suppressed within a necessary range.
The second region R2A in the modification is also the same as the second region R2.

The main tube 102A has a constant-thickness portion that surrounds the main lumen and has a constant thickness in the circumferential direction, and an air supply lumen. 1 is an example of a tube body having a thick-walled portion having a thickness greater than that of a constant-thickness portion;
The first region R1A is an example of a first region formed in a thick portion and including an air supply lumen.
The second region R2A is an example of a second region that is adjacent to the first region in the circumferential direction and has lower rigidity than both the first region and the constant thickness portion.
The thickness change portion Tv formed in the second region R2A is an example of a thickness change portion that is recessed radially outward from the inner peripheral surface of the main lumen and whose thickness changes.

[Third embodiment]
An endoscope overtube according to a third embodiment of the present invention will be described.
An overtube 201 shown in FIG. 17 is an example of an endoscope overtube according to this embodiment.
The overtube 201 has an air supply device 210 instead of the air supply device 10 of the overtube 1 according to the first embodiment.
In the following, the points different from the first embodiment will be mainly described.

FIG. 26 is a schematic front view showing an air supply device in an endoscope overtube according to a third embodiment of the present invention; FIG. 27 is a schematic front view similarly showing the arrangement of the air supply device during inhalation.
As shown in FIG. 26 , the air supply device 210 has a manual air supply mechanism 211 , a body portion 212 and a connecting band 216 .

The manual air supply mechanism 211 has an appropriate configuration for manually supplying and inhaling air. For example, the manual air supply mechanism 211 includes a pump 211a (manual pump), a first check valve 211b, a second check valve 211c, a first connector 211d (pump-side connector, first connector), and a second connector. 211e (pump-side connector, second connector).

The pump 211a is not particularly limited as long as it is a manual pump that sends gas. For example, the pump 211a may be a rubber bulb pump, a diaphragm pump, a bellows tube pump, a syringe pump, or the like. In the example shown in FIG. 26, the pump 211a is a rubber bulb pump. In this case, the pump 211a consists of an egg-shaped or rugby ball-shaped rubber ball. Tubular portions through which air flows are formed at both ends of the pump 211a in the longitudinal direction.

Each tubular portion is provided with a first check valve 211b and a second check valve 211c.
In the tubular portion where the first check valve 211b is arranged, a first opening 211g (see FIG. 27) communicating with the inside of the pump 211a when the first check valve 211b is opened is provided outside the first check valve 211b. ) is formed.
In the tubular portion where the second check valve 211c is arranged, a second opening 211f (see FIG. 26) that communicates with the inside of the pump 211a when the second check valve 211c is open is provided outside the second check valve 211c. )) are formed.

The first check valve 211b circulates the air inside the pump 211a to the outside through the opening of the tubular part in which the first check valve 211b is arranged, and prevents the outside air from entering the inside from the opening of the tubular part. prevent.
The second check valve 211c allows the air outside the pump 211a to flow inside through the opening of the tubular portion in which the second check valve 211c is arranged, and prevents the internal air from flowing out from the opening of the tubular portion. prevent.

The first connecting portion 211d is provided outside the first opening 211g (see FIG. 27) in the tubular portion where the first check valve 211b is arranged. The first connection portion 211d is detachably connected to a connection pipe 212a in the body portion 212, which will be described later.
The connection structure between the first connection portion 211d and the connection pipe 212a is not particularly limited as long as it can be detachably connected. For example, a luer lock connector may be used as the first connecting portion 211d. For example, when the connecting tube 212a is of the female luer lock type, the first connecting portion 211d is a male luer lock type connector.
The second connecting portion 211e is provided outside the second opening 211f (see FIG. 27) in the tubular portion where the second check valve 211c is arranged. The second connecting portion 211e is detachably connected to the connecting pipe 212a. For example, a luer lock type connector similar to the first connection portion 211d may be used as the second connection portion 211e.

The body part 212 is a housing in which a flow path through which air flows is formed.
The body portion 212 has a connecting tube 212a (body-side connector), an air pipe 210a, a relief valve 213, and a grip 215 (holding portion).

The connecting pipe 212a protrudes outside the housing of the main body 212. The connection tube 212a allows the manual air supply mechanism 211 to be detachable from the first connection portion 211d and the second connection portion 211e. The inside of the connection pipe 212a communicates with the manual air supply mechanism 211 when either the first connection portion 211d or the second connection portion 211e is attached.

The air pipe 210 a protrudes outside the housing of the main body 212 . Inside the housing of the main body part 212, a flow path is formed between the air supply pipe 210a and the connection pipe 212a through which the air supplied from the manual air supply mechanism 211 flows.
The air pipe 210 a is connected to the air flow tube 9 and communicates with the flow path inside the air flow tube 9 .

The relief valve 213 is arranged on the outer peripheral portion of the housing of the main body portion 212 . The relief valve 213 is the same as the relief valve 113 in the first embodiment except that it is provided on the flow path between the connecting pipe 212a and the air supply pipe 210a. Details of the flow path between the connecting tube 212a and the air supply tube 210a will be described later.

The grip 215 protrudes from the outer peripheral portion of the body portion 212 . The shape of the grip 215 is not particularly limited as long as the user can grip the body portion 212 .

The connection state of the manual air supply mechanism 211 to the body portion 212 includes a first connection state in which the first connection portion 211d shown in FIG. and a second connection state connected to the .
The operator can manually switch between the first connection state and the second connection state. For example, to switch the first connection state to the second connection state, the operator unlocks the first connection portion 211d and removes the first connection portion 211d from the connection tube 212a. The operator changes the orientation of the manual air supply mechanism 211, connects the second connection portion 211e to the connection tube 212a, and locks the second connection portion 211e. To switch from the second connected state to the first connected state, the opposite operation is performed.
In the first connection state, air supplied from the first opening 211g by the operator's operation of the pump 211a flows into the connection tube 212a.
In the second connection state, the air sucked by the operator's operation of the pump 211a flows from the connection tube 212a into the second opening 211f.
Therefore, in the air supply pipe 210a communicating with the connection pipe 212a, the direction of air flow is changed depending on the connection state of the manual air supply mechanism 211. FIG.

The connecting band 216 connects the main body portion 212 and the manual air-supplying mechanism 211 so as not to interfere with the movement and posture change of the manual air-supplying mechanism 211 required for switching the connected state of the manual air-supplying mechanism 211 .
For example, the connecting band 216 is made of flexible resin. The mounting position of the connection band 216 on the main body 212 and the manual air supply mechanism 211 is not particularly limited as long as the movement and posture change of the manual air supply mechanism 211 are not hindered. In the example shown in FIG. 26, they are rotatably mounted on the outer peripheral portion of the connection pipe 212a of the main body portion 212 and the outside of the tubular portion between the first connection portion 211d and the pump 211a.
As shown in FIG. 27, the length of the connecting band 216 is sufficiently longer than the length from the first connecting portion 211d to the second connecting portion 211e of the manual air supply mechanism 211. As shown in FIG.

A functional configuration of the air supply device 210 will be described with reference to FIGS. 28 and 29. FIG.
FIG. 28 is a block diagram showing an example of an air supply device in the endoscope overtube according to the third embodiment of the present invention. FIG. 29 is a block diagram similarly showing the flow of the air supply device during inspiration.

As shown in FIG. 28, the air supply device 210 includes the manual air supply mechanism 211 and the relief valve instead of the air supply mechanism 111, the relief valve 113, and the connection pipe 110a of the air supply mechanism 111 in the first embodiment. 213, with air line 210a. The airflow tube 9 similar to that of the first embodiment is connected to the air pipe 210a (see FIG. 27).

As shown in FIG. 28, the manual air supply mechanism 211 includes a pump 111a, a first check valve 111b, a second check valve 111c, a first channel switching portion 111d, a second channel switching portion 111e, and an opening. Instead of 111f, it has a pump 211a, a first check valve 211b, a second check valve 211c, a first pipeline switching section SW1, a second pipeline switching section SW2, and an opening O.
As with the first channel switching unit 111d, the first channel switching unit SW1 may use a channel switching valve or the like, but in the example shown in FIGS. do.
Therefore, in the first connection state, as shown in FIG. 28, the first connection portion 211d and the second connection portion 211e correspond to the first channel switching portion SW1 and the second channel switching portion SW2, respectively. In this case, the opening O corresponds to the second opening 211f.
Similarly, in the second connection state, as shown in FIG. 29, the second connection portion 211e and the first connection portion 211d correspond to the first channel switching portion SW1 and the second channel switching portion SW2, respectively. In this case, the opening O corresponds to the first opening 211g.

In the manual air supply mechanism 211 in the first connected state, as indicated by the solid line in FIG. 28, an air flow similar to that of the air supply device 10 of the first embodiment is formed, and air is supplied to the connecting tube 212a.
In the manual air supply mechanism 211 in the second connected state, as indicated by the dashed line in FIG. 29, an airflow similar to that of the air supply device 10 of the first embodiment is formed, and air is sucked through the connecting tube 212a.

As shown in FIG. 28, between the connecting pipe 212a and the air pipe 210a, a first pipe P1, a constricted portion P2, and a second pipe P3 are arranged in this order from the connecting pipe 212a toward the air pipe 210a. are placed.
The first pipeline P1 circulates air between the connecting pipe 212a and the constricted portion P2.
The throttle portion P2 is provided for the purpose of reducing the pressure of the air supplied from the first pipeline P1. The configuration of the narrowed portion P2 is not particularly limited as long as the pressure of the air after passing through the narrowed portion P2 can be reduced by reducing the flow passage cross-sectional area. For example, the narrowed portion P2 may be formed of a tubular portion extending from a pipe having a flow passage cross-sectional area smaller than that of the first pipe P1. For example, the constricted portion P2 protrudes inward from the pipe wall of the first pipe P1 into the pipe of the first pipe P1, and an orifice smaller than the pipe cross-sectional area of the first pipe P1 is formed. It may be formed by an orifice plate. For example, the constricted portion P2 may be formed of a porous body whose opening area as a whole is smaller than the duct cross-sectional area of the first duct P1.
The second pipe line P3 is formed by a pipe having a larger flow channel cross-sectional area than the flow channel cross-sectional area at the constricted portion P2. In this embodiment, the second conduit P3 is extended to the rear end of the second lumen 2e by the airflow tube 9 connected to the air supply pipe 210a.
A relief valve 213 is connected to the second pipeline P3 between the air supply pipe 210a and the throttle portion P2.
The relief valve 213 is the same as the relief valve 113 in the second embodiment except that it is provided in the second pipeline P3. Therefore, when the pressure of the air in the second pipeline P3 becomes higher than the allowable value, the air is discharged from the relief valve 213 to the outside of the main body 212 (see FIG. 27).

The functional configuration of the air supply device 210 shown in FIGS. 26 and 27 can also be represented by a block diagram as shown in FIG.
FIG. 30 is a block diagram showing an example of an air supply device in the endoscope overtube according to the third embodiment of the present invention.
As shown in FIG. 30, the manual air supply mechanism 211 has a channel switching section 211h instead of the first channel switching section SW1 and the second channel switching section SW2.
The channel switching unit 211h forms the first connection state during air supply indicated by the black line. As a result, the first connecting portion 211d is connected to the connecting pipe 212a, and the connecting pipe 212a communicates with the first opening 211g. At this time, external air is sucked through the second opening 211f.
The channel switching unit 211h forms the second connection state during intake indicated by the dashed line. As a result, the second connecting portion 211e is connected to the connecting pipe 212a, the connecting pipe 212a is communicated with the second opening 211f, and the sucked air is discharged to the outside from the first opening 211g.
In this embodiment, the function of the channel switching unit 211h is implemented manually. However, the channel switching unit 211h may be replaced by a switching device such as a channel switching valve.

The air supply device 210 communicates with the fixation balloon 3 via the airflow tube 9 and the second lumen 2e, as in the first embodiment. As a result, the operator can switch the manual air supply mechanism 211 between the first connection state and the second connection state as appropriate to supply air to the fixation balloon 3 and air from the fixation balloon 3 . can be inhaled. Therefore, as in the first embodiment, the operator can expand and contract the fixation balloon 3 .

The operation of the present embodiment will be described with a focus on the operation of the constricted portion P2 in the air supply device 210. FIG.
First, the problem of air supply in a manual pump will be described with reference to FIGS. 31 and 32. FIG.
FIG. 31 is a schematic diagram explaining the action of a relief valve in a manual pump. However, in FIG. 31, illustration of the airflow tube 9 is omitted for simplification.
FIG. 32 is a graph showing an example of the relationship between the flow rate of air supplied by the manual pump and the amount of loss leaking from the relief valve. In FIG. 32, the horizontal axis represents time, and the vertical axis represents the flow rate of air supplied from the manual pump.

The overtube T shown in FIG. 31 has an overtube 201 from which the narrowed portion P2 is removed. Further, the overtube T has a pipeline P0 having a constant flow cross-sectional area instead of the first pipeline P1 and the second pipeline P3.
Let Q be the flow rate of air supplied to the conduit P0 by operating the pump 211a. As shown in FIG. 32, when the operator presses the pump 211a, the flow rate Q increases with time, reaches a maximum value _Qx , and then gradually decreases, as indicated by a curve 50. FIG. The flow rate Q becomes zero when there is no change in the volume of the pump 211a. If the diameter of the fixation balloon 3 is not expanded to the required size by this operation, the operator releases the pump 211a and inhales into the pump 211a, and then repeats the same operation.
The maximum value _Qx of the flow rate Q and the time required for the flow rate Q to reach the maximum value _Qx depend on the pressing force and pressing speed of the operator. The operator often presses the pump 211a to quickly increase the flow rate in order to quickly perform the treatment. As a result, for example, in the pipeline P0, it is assumed that the allowable pressure of the relief valve 213 is reached when the flow rate is equal to or higher than _Q1 ( _Q1 < _Qx ). In this case, the flow rate Q ₂ (=Q−Q ₁ ) exceeding Q ₁ in the flow rate Q is exhausted from the relief valve 213 to the outside.
In this case, air at a flow rate of _Q1 is supplied to the interior of the fixation balloon 3 to which the conduit P0 communicates through the airflow tube 9 and the second lumen 2e (not shown) of the main tube 2. FIG.

Therefore, the volume A1 of the air supplied to the fixation balloon 3 in _one pressing operation is a value obtained by integrating the curve 50 in the range less than _Q1 , as shown in FIG. Similarly, the loss volume _A2 of the air discharged from the relief valve 213 is a value obtained by integrating the curve 50 in the range of _Q1 or more.
It means that the larger the loss _{volume A2} to the volume A1, the lower the air supply efficiency of the air supply device of the overtube T. If the air supply efficiency is low, the operator has to operate the pump 211a for a longer time in order to expand the fixation balloon 3 to the required outer diameter, which increases the work time for treatment. .
As described above, with a manual pump, if the operator strongly or quickly operates the pump 211a, the operation time for expanding the diameter of the fixation balloon 3 may rather be lengthened.

In the present embodiment, in view of such problems, the air supply device 210 is provided with the narrowed portion P2. This enables the operator to perform a more efficient air supply operation.
When the throttle portion P2 is formed between the first pipeline P1 and the second pipeline P3, even if the operator strongly presses the pump 211a, the throttle portion P2 provided on the upstream side of the relief valve 213 will The flow rate of air flowing into the second pipeline P3 is reduced. As a result, the pressure inside the second pipeline P3 including the airflow tube 9 is reduced. As a result, the amount of air lost in the relief valve 213 is also reduced.
Furthermore, since the channel resistance increases due to the constricted portion P2, the operator must press the pump 211a more strongly than when the constricted portion P2 does not exist to increase the flow rate. The magnitude of the flow resistance is transmitted as a sense of resistance to the operating operator through the pump 211a. This sense of resistance also has the effect of making the operator relax the pressing force.

According to the present embodiment, the provision of the constricted portion P2 enables the fixation balloon 3 to expand in diameter with less air loss than when the constricted portion P2 does not exist. The time to operate the pump 211a is reduced.

Next, conditions for a shape suitable for the constricted portion P2 will be described.
FIG. 33 is a schematic diagram showing the flow channel shape of the air supply device in the endoscope overtube according to the third embodiment of the present invention.
The shape of the first conduit P1 is a cylinder with an inner diameter of D [mm].
The shape of the constricted portion P2 is a cylindrical flow path with an inner diameter of d [mm] and a length of L ₁ [mm]. For example, if the constricted portion P2 is not cylindrical, the diameter of a circle having the same cross-sectional area is used as d. For example, if the diaphragm portion P2 is a square with a side length of s, 2×s/√π is used as d. For example, when the constricted portion P2 is formed of a porous material, 2×r×√N is used, where r is the average radius of the holes in the cross section perpendicular to the flow path, and N is the number of holes.
The shape of the second pipeline P3 is a cylindrical flow path with an inner diameter of D [mm]. The same applies to the inner diameter of the airflow tube 9 connected to the air supply pipe 210a and forming part of the second pipeline P3. Hereinafter, the entire length of the _second pipeline P3 including the airflow tube 9 is represented by L2 [mm].
When the first pipeline P1 and the second pipeline P3 are directly connected without the throttle part P2 (hereinafter referred to as the case without the throttle part), the flow rate is q [L / min], and the throttle part P2 exists. Let q' [L/min] be the flow rate in the case of

It is empirically known that the pressure P1 in the _first pipeline P1 and the pressure P3 in the _second pipeline P3 follow the Darcy-Weisbach equation when the restrictor P2 is absent. P ₁ and P ₃ are equal to each other and represented by the following formula (3a).

Assuming that the flow rate when the throttle portion P2 exists is q', the pressure P ₁ ' in the first pipeline P1 and the pressure P ₃ ' in the second pipeline P3 are expressed by the following equations (3b), ( 3c).

P ₁ and P ₁ ′ _are the input pressures of the pump 211a. P ₁ and P ₁ ′ are equal to each other. The condition under which the pressure P ₁ ' in the path P1 is less than 90% is the following formula (3d).
Here, "less than 90%" is an example considering practicality. Setting the pressure P ₃ ' to less than 90% of the pressure P ₁ ' is preferable because the loss of air exhausted from the relief valve 213 can be reduced.
However, if the pressure P ₃ ′ is too low, the expansion speed of the fixation balloon 3 may become too slow. It is more preferable to determine the pressure P ₃ ' so that the rate of diameter expansion of the fixation balloon 3 becomes an appropriate value within a range of less than 90%. For example, the pressure P ₃ ′ may be 80% or more of P ₁ ′, more preferably 50% or more.
For example, the condition of the constricted portion P2 may be determined such that the pressure P ₃ ′ is less than 80%, less than 70%, etc. of the pressure P ₁ ′.

By substituting equations (3b) and (3c) into equation (3d) and arranging them, the following equation (3e) is obtained.

In the present embodiment, if the shapes of the throttle portion P2 and the second pipe line P3 satisfy the condition of expression (3e), the second pipe line on the downstream side of the throttle portion P2 can be supplied when the pump 211a is operated to supply air. The pressure in P3 can be less than 90% of the pressure upstream of restriction P2. As a result, the loss amount of the air exhausted from the relief valve 213 communicating with the second pipe line P3 on the downstream side of the throttle portion P2 is reduced.
In order to rewrite the equation (3e) under the condition that the pressure is less than X%, the coefficient "1/9" in the equation (3e) should be replaced with "1/(0.1×X)".

The overtube 201 of this embodiment is the same as the overtube 1 except that it has an air supply device 210 instead of the air supply device 10 of the overtube 1 according to the first embodiment. Therefore, as in the first embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this embodiment, the air supply device 210 has the manual air supply mechanism 211, and the air supply device 210 has the throttle portion P2. As a result, the diameter of the fixation balloon 3 can be expanded with a smaller amount of air loss than in the case where the constricted portion P2 does not exist, so the time required for the operator to operate the pump 211a is reduced.

A first pipeline P1 in the air supply device 210 is an example of a first pipeline through which gas sent from a pump 211a, which is an example of a manual pump, flows.
The constricted portion P2 in the air supply device 210 is an example of a constricted portion that is connected to the first pipeline and has a flow channel cross-sectional area smaller than the flow channel cross-sectional area of the first pipeline.
The second duct P3 in the air supply device 210 is an example of a second duct that has a channel cross-sectional area larger than the flow channel cross-sectional area of the constricted portion, and causes the gas flowing through the constricted portion to flow toward the fixation balloon. be.
The relief valve 213 is an example of a relief valve that is provided in the second pipeline and exhausts gas from the second pipeline when the pressure in the second pipeline exceeds a certain value.

[First modification]
A modification (first modification) of the air supply device used in place of the air supply device 210 in the overtube 201 according to the third embodiment will be described.
As shown in FIG. 17, an air supply device 210A of this modified example can be used in place of the air supply device 210 of the overtube 201. As shown in FIG.
As shown in FIG. 26, the air supply device 210A has a body portion 212A instead of the body portion 212 of the air supply device 210. As shown in FIG.
The body portion 212A differs from the body portion 212 in the structure of the flow path from the connection tube 212a to the air supply tube 210a. In the following, the points different from the third embodiment will be mainly described.

FIG. 34 is a block diagram showing a modified example (first modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention. FIG. 35 is a schematic diagram showing a flow path shape of a modified example (first modified example) of the air supply device.
As shown in FIG. 34, the air supply device 210A has an expanded diameter portion P4 instead of the constricted portion P2. However, the relief valve 213 in this modified example is arranged in the enlarged diameter portion P4.
The enlarged diameter portion P4 is provided for the purpose of reducing the pressure of the air supplied from the first pipeline P1. The enlarged diameter portion P4 is a housing having a flow channel cross-sectional area larger than each flow channel cross-sectional area of the first pipeline P1 and the second pipeline P3. The channel cross-sectional area of the enlarged diameter portion P4 is the area of the cross section orthogonal to the air flow direction from the first pipeline P1 to the second pipeline P3.
The shape of the diameter-enlarged portion P4 is not particularly limited as long as the air pressure in the diameter-enlarged portion P4 can be reduced below the pressure of the first pipe line P1.
For example, the enlarged diameter portion P4 may be formed of a tubular portion having a flow passage cross-sectional area larger than that of the first pipeline P1. For example, the enlarged diameter portion P4 may be box-shaped with a cross-sectional area larger than the inner diameter of the first pipeline P1.
The expanded diameter portion P4 in FIG. 35 is modeled in a box shape with a V volume. The shape of the cross section of the flow path in the enlarged diameter portion P4 is not particularly limited. The cross-sectional shape of the enlarged diameter portion P4 may be circular, elliptical, rectangular, polygonal, or the like.

The action of this modified example will be described with a focus on the action of the expanded diameter portion P4 in the air supply device 210A.
In this modification, the air supply device 210A is provided with an enlarged diameter portion P4, and a relief valve 213 is arranged in the enlarged diameter portion P4, thereby allowing the operator to perform more efficient air supply operation.
If the diameter-enlarged portion P4 is formed between the first pipeline P1 and the second pipeline P3, the cross-sectional area of the flow path is widened at the diameter-enlarged portion P4. becomes a lower pressure. As a result, when the flow rate by the operation by the operator is the same, the time required for the pressure in the enlarged diameter portion P4 to reach the allowable pressure exhausted from the relief valve 213 arranged in the enlarged diameter portion P4 is extended.
Therefore, the internal pressure of the enlarged diameter portion P4 increases without air being exhausted, and during this time air continues to flow to the first pipeline P1 to some extent.
As a result, the loss of air exhausted from the relief valve 213 is reduced.

Next, conditions for a shape suitable for the enlarged diameter portion P4 will be described. The unit system in the formulas of this modified example is not particularly limited.
The shape of the first pipeline P1 and the second pipeline P3 is a cylinder with an inner diameter D, as in the third embodiment.
The volume of the expanded diameter portion P4 is V. Let P be the pressure before the expanded diameter portion P4 is increased in pressure by the air supply from the pump 211a. Assuming that _P ' is the pressure when the volume QP of air flows from the pump 211a into the expanded diameter portion P4, the following equation (3f) is obtained from the Boyle-Charles law. Here, it is assumed that air does not flow out from the enlarged diameter portion P4 when air flows in. FIG.
For example, the volume QP may be the maximum air supply amount of the pump _211a in one operation. For example, the volume _QP can be the maximum insufflation volume in the pump 211a. In this case, P' is the pressure inside the enlarged diameter portion P4 at the time of maximum air supply in one operation.

The volume V' per unit length of the cylindrical tube when a cylindrical tube having an inner diameter similar to that of the second pipeline P3 is arranged instead of the enlarged diameter portion P4 is represented by the following formula (3g). .

Assuming that the pressure when air having a volume QP flows into such a cylindrical tube from the pump 211a is _P '', the following equation (3h) is obtained based on the same assumption as the calculation of P'.

The condition under which the pressure P′ of the enlarged diameter portion P4 is less than 90% of the pressure P″ without the enlarged diameter portion P4 is the following formula (3i).
Here, "less than 90%" is an example considering practicality. Setting the pressure P′ to less than 90% of the pressure P″ is preferable because the amount of loss of air exhausted from the relief valve 213 can be reduced.
However, if the pressure P' is too low, the expansion speed of the fixation balloon 3 may become too slow. More preferably, the pressure P′ is determined so that the speed of expanding the diameter of the fixation balloon 3 becomes an appropriate value within a range of less than 90%. For example, the pressure P' may be 80% or more of P'', more preferably 50% or more.
At the same time, the expansion speed of the fixation balloon 3 can be maintained as much as possible.
For example, the pressure P' may be set to less than 80%, less than 70%, etc. of the pressure P'' to determine the condition of the enlarged diameter portion P4.

By substituting equations (3f) and (3h) into equation (3i) and arranging them, the following equation (3j) is obtained.

In this modified example, if the shapes of the enlarged diameter portion P4 and the first pipeline P1 satisfy the condition of expression (3e), when the pump 211a is operated to supply air, the pressure inside the enlarged diameter portion P4 is changed to It can be less than 90% of the pressure inside the first conduit P1. As a result, the loss of air exhausted from the relief valve 213 is reduced.

An overtube 201 having an air supply device 210A of this modified example is the same as the overtube 201 except that it has an air supply device 210A instead of the air supply device 210 of the overtube 201 according to the third embodiment. is. Therefore, according to this modified example, as in the third embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this modified example, the air supply device 210A has the enlarged diameter portion P4 provided with the relief valve 213 .
As a result, the diameter of the fixation balloon 3 can be expanded with a smaller amount of air loss than when the expanded diameter portion P4 does not exist, thus reducing the time required for the operator to operate the pump 211a.

The enlarged diameter portion P4 in the air supply device 210A is an example of an enlarged diameter portion that is connected to the first conduit and has a channel cross-sectional area larger than that of the first conduit.
The relief valve 213 in the air supply device 210A is an example of a relief valve that is provided in the enlarged diameter portion and exhausts gas from the enlarged diameter portion when the pressure in the enlarged diameter portion exceeds a certain value.
The second pipeline P3 in the air supply device 210A has a flow channel cross-sectional area smaller than the flow channel cross-sectional area of the enlarged diameter portion, and allows the gas flowing through the enlarged diameter portion to flow toward the fixation balloon. is an example of

[Second modification]
A modification (second modification) of the air supply device used in place of the air supply device 210 in the overtube 201 of the third embodiment will be described.
As shown in FIG. 17, an air supply device 210B of this modification can be used in place of the air supply device 210 of the overtube 201. As shown in FIG.
FIG. 36 is a schematic front view showing a modified example (second modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention.

As shown in FIG. 36, the air supply device 210B has a body portion 212B instead of the body portion 212 of the air supply device 210. As shown in FIG.
The main body portion 212B has a pressure adjusting portion 217 and a housing portion 218 between the connecting pipe 212a and the air pipe 210a.
A grip 215 in this modified example is formed in a housing portion 218 .
As with the manual air supply mechanism 211 in the second embodiment, the manual air supply mechanism 211 in this modification can switch between the first connection state and the second connection state with respect to the connecting pipe 212a of the main body 212B. is.
In the following, the points different from the third embodiment will be mainly described.

FIG. 37 is a block diagram showing a modified example (second modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention. FIG. 38 is a schematic diagram showing a flow channel shape of a modified example (second modified example) of the air supply device. However, the illustration of the airflow tube 9 is omitted in FIG. 38 for the sake of simplification (the same applies to FIGS. 39 to 40 below).

As shown in FIG. 37, an air supply device 210B has a throttle portion P2 and a relief valve 213 similar to those of the third embodiment.
The diaphragm portion P2 in this modified example is arranged inside the housing portion 218 .
The relief valve 213 in this modified example communicates with the second pipe line P3 inside the housing portion 218 .
As schematically shown in FIG. 38, the pressure adjustment section 217 communicates with the first pipeline P1 through the third pipeline P5.

The pressure adjustment unit 217 branches the air supplied from the pump 211a through the first pipe line P1, and stores the air inside without discharging it to the outside. As a result, the pressure increase in the first pipeline P1 is alleviated, and the pressure of the air flowing through the throttle portion P2 to the second pipeline P3 is also alleviated.
The configuration of the pressure adjusting section 217 is not particularly limited as long as the pressure rise in the first pipeline P1 can be alleviated by storing air inside the pressure adjusting section 217 .

For example, the pressure adjustment part 217 may be configured to form a storage space for storing the air to be supplied to the first pipeline P1.
For example, the pressure adjusting part 217 may be formed of a box, a cylinder, etc. forming a storage space having a certain volume. In this case, the internal pressure of the first pipe line P1 and the internal pressure of the pressure adjusting section 217 rise due to the air flowing into the pressure adjusting section 217 . However, since the volume into which air flows is as large as the pressure regulating portion 217, the pressure rise in the first pipeline P1 is reduced compared to the case where the pressure regulating portion 217 is not provided.
The larger the volume of the pressure adjusting portion 217, the more the pressure rise in the first pipeline P1 is mitigated.
When the internal pressure of the pressure regulating portion 217 increases to some extent and exceeds the flow path resistance of the constricted portion P2, the air stored in the pressure regulating portion 217 returns to the first duct P1 through the third duct P5 and flows through the constricted portion P2. It is pushed out towards the fixation balloon 3 .

For example, the pressure adjustment part 217 may be configured to form a storage space whose volume changes according to the pressure in the first pipeline P1. Examples of the pressure adjustment part 217 whose volume changes include a syringe, a bellows tube, a bag, etc., whose volume changes by deformation according to the internal pressure.
The volume-changing pressure adjustment part 217 may be formed of an elastic body that expands and contracts according to pressure.
The volume-changing pressure adjustment section 217 may have an elastic member that applies an elastic force that resists the volume change.

FIG. 39 is a schematic diagram showing an example of a modified example (second modified example) of the air supply device.
A pressure regulating portion 217A shown in FIG. 39 is an example of the pressure regulating portion 217 whose volume changes.
217 A of pressure adjustment parts have the cylindrical part 217a, the piston 217b, and the spring 217c.

The tubular portion 217a is, for example, a cylinder elongated in one direction, a rectangular tube, or the like. A third pipe line P5 communicates with a longitudinal end of the tubular portion 217a.
The piston 217b is movable in the longitudinal direction of the tubular portion 217a inside the tubular portion 217a. The piston 217b divides the tubular portion 217a in the longitudinal direction into a first space Sa and a second space Sb. The cylindrical portion 217a slides on the inner surface of the cylindrical portion 217a while maintaining airtightness, and is movable in the longitudinal direction.
The opening of the third pipeline P5 faces the first space Sa.
The spring 217c is arranged in the second space Sb and elastically connects the longitudinal end of the tubular portion 217a in the second space Sb and the piston 217b.
The spring 217c urges the piston 217b against the pressure in the first space Sa.

According to the pressure adjustment section 217A, when the pump 211a is operated and air is supplied to the first pipeline P1, more air flows into the third pipeline P5, which has a smaller flow path resistance than the throttle section P2. flow.
The air that has flowed into the first space Sa from the third conduit P5 flows into the first space Sa until the pressure reaches a balance with the biasing force of the spring 217c. The air that has flowed into the first space Sa passes through the piston 217b and is biased by the spring 217c.
When the air supply by the pump 211a ends and the flow rate of the air flowing through the first pipeline P1 decreases, the piston 217b moves toward the third pipeline P5 according to the biasing force from the spring 217c. As a result, the air in the first space Sa is pushed out from the third pipeline P5. Therefore, the air stored in the first space Sa returns to the first pipeline P1 through the third pipeline P5. This supplies the fixation balloon 3 with no loss of stored air.
The first space Sa is an example of a volume-variable storage space in the pressure adjustment section 217A.

FIG. 40 is a schematic diagram showing an example of a modified example (second modified example) of the air supply device.
A pressure regulating portion 217B shown in FIG. 40 is an example of the pressure regulating portion 217 whose volume changes.
The pressure adjusting portion 217B has a balloon 217d instead of the tubular portion 217a, the piston 217b, and the spring 217c of the pressure adjusting portion 217A.
The balloon 217d is made of a bag-like elastomer having one opening that communicates with the third conduit P5. As the material of the balloon 217d, an elastomer having appropriate elasticity that can be expanded and contracted according to the pressure of the air in the first pipeline P1 is used.

According to the pressure adjustment part 217B, when the pump 211a is operated and air is supplied to the first pipeline P1, the air flowing toward the third pipeline P5 flows into the inside. The internal space Sc of the pressure adjusting section 217B expands according to the air pressure.
The air that has flowed into the internal space Sc flows into the internal space Sc until it reaches a pressure that balances the tension of the balloon 217d. The air that has flowed into the internal space Sc is urged from the balloon 217d.
When the air supply by the pump 211a ends and the flow rate of the air flowing through the first pipeline P1 decreases, the air in the internal space Sc is pushed out from the third pipeline P5 according to the biasing force from the balloon 217d. Therefore, the air stored in the internal space Sc returns to the first pipeline P1 through the third pipeline P5, similarly to the pressure adjustment section 217A. This supplies the fixation balloon 3 with no loss of stored air.
The internal space Sc is an example of a volume-variable storage space in the pressure adjustment section 217B.

The configuration of the pressure adjustment units 217A and 217B may be included in devices such as pressure gauges and pressure indicators that display pressure, for example. In this case, a device such as a pressure gauge or a pressure indicator may be used as the pressure adjustment unit 217 .

Next, an example of an air supply operation using the air supply device 210B will be described with a focus on the action of the pressure adjustment section 217. FIG.
41 to 44 are explanatory diagrams of the operation of the modified example (second modified example) of the air supply device.
However, in FIGS. 41 to 44, illustration of the airflow tube 9 is omitted for simplification.

As shown in FIG. 41, when the operator starts to push the pump 211a, part of the air supplied to the first conduit P1 flows through the narrowed portion P2, the second conduit P3, and the airflow tube 9 (not shown). , and the second lumen 2 e in the main tube 2 , into the fixation balloon 3 .
Other than the supplied air, it branches to the pressure adjustment section 217 through the third conduit P5. Therefore, even if the operator presses the pump 211a sharply or strongly, an excessive amount of air does not flow into the constricted portion P2. In FIG. 41, the amount of inflow of air is schematically shown by hatching. The white portion shown in the figure does not mean a vacuum, but schematically shows a state in which air can easily flow.
For example, when the pressure adjustment part 217 is formed of a bag or a balloon, the initial volume of the pressure adjustment part 217 is close to 0, and if the air pressure exceeds the atmospheric pressure outside the pressure adjustment part 217, can flow in easily.
For example, if the pressure adjusting unit 217 is formed of a box having a certain volume, the pressure increases in proportion to the amount of inflow. However, if the volume of the pressure adjusting portion 217 is sufficiently large, the gradient of the pressure rise can be reduced.

The throttle portion P2 in this modified example has the effect of alleviating the pressure rise in the second pipeline P3 on the downstream side, like the throttle portion P2 in the third embodiment. In this modification, the increase in pressure in the second pipeline P3 is further suppressed in combination with the pressure relaxation effect of the expanded diameter portion P4.
This makes it difficult for the air in the second pipeline P3 to be exhausted from the relief valve 213 even if the operator presses the pump 211a sharply or strongly.

When the pressure adjusting section 217 is formed of a pressure gauge or a pressure indicator, the operator can adjust the amount of air supply by observing the pressure displayed by the pressure adjusting section 217 during the air supply operation. In this respect as well, air is less likely to be discharged from the relief valve 213 .
Air efficiently flows into the fixation balloon 3, and the fixation balloon 3 is inflated.

As shown by the shaded area in FIG. 42, when air flows into the pressure adjustment section 217 to some extent, the internal pressure of the pressure adjustment section 217 gradually increases. As a result, the resistance that the operator receives from the pump 211a gradually increases.
The operator can recognize that sufficient air has been supplied to the fixation balloon 3 because the operator receives a large amount of resistance after the air supply takes a certain amount of time.
As a result, the operator releases the pump 211a to stop the air supply (see FIG. 43). Even if the operator does not stop the air supply, if the pressure in the second conduit P3 exceeds the allowable pressure, the pressure is exhausted from the relief valve 213, so the fixation balloon 3 is not overinflated. In this case, the air supply resistance is maintained at a constant high level, so the operator stops the air supply without too much time.

When the air supply is stopped, the increase in the amount of air in the air flow path inside the overtube 201 having the air supply device 210B stops.
Since the internal pressure of the pressure regulating portion 217 rises to some extent at the time of stopping, the air inside the pressure regulating portion 217 flows into the fixation balloon 3 even after the stop according to the internal pressure at the time of stopping. Therefore, even if the fixation balloon 3 is stopped in a state where the diameter expansion amount of the fixation balloon 3 is small, insufficient air is supplied to the fixation balloon 3 within the range of the volume of the pressure adjusting portion 217 .
If the pressure adjusting section 217 has a configuration capable of urging the internal air, for example, like the pressure adjusting sections 217A and 217B, the air in the pressure adjusting section 217 tends to move to the fixation balloon 3 more quickly.

As shown in FIG. 44, when the air moves until the pressure PB inside the fixation balloon 3 and the pressure _PG inside the pressure adjusting portion 217 are balanced, a pressure equilibrium state is formed inside the _overtube 201 .
This completes the operation for expanding the diameter of the fixation balloon 3 .

When the diameter of the fixation balloon 3 is reduced, the air in the fixation balloon 3 is sucked by the manual air supply mechanism 211 .
The manual air-supplying mechanism 211 of this modified example is similar to the manual air-supplying mechanism 211 in the second embodiment, by switching the connection state of the manual air-supplying mechanism 211 to the second connection state and then operating the pump 211a. , rapid inspiration is possible.
When air remains in the pressure adjusting portion 217 at the time of inhalation, the air in the pressure adjusting portion 217 is also inhaled together with the air in the fixation balloon 3 .
If the pressure adjustment section 217 is energized with air like the pressure adjustment sections 217A and 217B, for example, the time required for intake can be further shortened. In this case, the operator can perform the inhalation operation more quickly and easily.

An overtube 201 having an air supply device 210B of this modified example is the same as the overtube 201 except that it has an air supply device 210B instead of the air supply device 210 of the overtube 201 according to the third embodiment. is. Therefore, according to this modified example, as in the third embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this modification, the air supply device 210B further has a pressure adjustment section 217 in addition to the air supply device 210 .
As a result, compared to the air supply device 210, the pressure rise on the downstream side of the constricted portion P2 can be further suppressed. As a result, the diameter of the fixation balloon 3 can be expanded with a small amount of air loss, so the time required for the operator to operate the pump 211a is reduced.

The pressure adjusting units 217, 217A, and 217B in the air supply device 210B are connected to the first pipeline, have flow paths having a flow path cross-sectional area larger than the flow path cross-sectional area of the first pipeline, and are connected to the first pipeline. 1 is an example of a pressure indicator that displays channel pressure.
The internal space in the pressure adjusting section 217, the first space Sa in the pressure adjusting section 217A, and the internal space Sc in the pressure adjusting section 217B form flow paths through which air flows. It has a road cross-sectional area.

[Third modification]
A modification (third modification) of the air supply device used in place of the air supply device 210 in the overtube 201 of the third embodiment will be described.
As shown in FIG. 17, an air supply device 210C of this modified example can be used in place of the air supply device 210 of the overtube 201. As shown in FIG.
FIG. 45 is a schematic front view showing a modified example (third modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention. FIG. 46 is a block diagram showing a modified example (third modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention.

As shown in FIG. 45, the air supply device 210C has a main body portion 212C instead of the main body portion 212 of the air supply device 210. As shown in FIG.
The body portion 212C has a pressure indicator 219 and a housing portion 218 similar to that of the second modification between the connection tube 212a and the air supply tube 210a.
As shown in FIG. 46, the pressure indicator 219 communicates with the first conduit P1 through the third conduit P5, like the pressure adjusting section 217 in the second modified example.
A grip 215 in this modified example is formed on a housing portion 218 as in the second modified example.
In the following, the points different from the third embodiment will be mainly described.

FIG. 45 shows a standard arrangement when the operator holds and operates the air supply device 210C with the right hand _HR and the left hand _HL . The operator holds the grip 215 with the left hand _HL to support the air supply device 210C. The operator holds the pump 211a with the right hand _HR . The operator pushes the pump 211a when performing air supply or suction operation. The state in which the air supply device 210C is held in both hands and placed in front of the operator is referred to as a standard operating state.
The outer shape of the pressure indicator 219 is a columnar shape extending along the central axis Ai. The cross-sectional shape in the direction perpendicular to the central axis Ai is not particularly limited. For example, the cross-sectional shape of pressure indicator 219 may be circular, elliptical, rectangular, polygonal, or the like. In the example shown in FIG. 45, the outer shape of the pressure indicator 219 is cylindrical extending along the central axis Ai.
In the air supply device 210C, the grip 215 and the manual air supply mechanism 211 are arranged so that the central axis Ai can easily take a posture extending in the lateral direction of the operator in the standard operating state.

The grip 215 in this modified example is arranged from the housing part 218 arranged on the left side of the pressure indicator 219 in FIG. Inclined. The central axis _AG of the grip 215 is inclined by an angle _θL with respect to the central axis Ai counterclockwise in the figure. For example, the angle θ _L may be 15° or more and 90° or less. For example, the angle θ _L is more preferably in the range of 60°±15°.

The manual air-supply mechanism 211 in this modified example moves toward the operator ( bottom in the drawing). The central axis A _P of the manual air supply mechanism 211 is inclined by an angle θ _R with respect to the central axis Ai in the clockwise direction. For example, the angle θ _R may be 15° or more and 90° or less. For example, the angle θ _R is more preferably in the range of 60°±15°.
When the pump 211a is a rubber ball pump, the central axis _AP coincides with the central axis of the pump 211a, and is the axis connecting the center of the first connection portion 211d and the center of the second connection portion 211e.
In this case, the angle θ _R coincides with the inclination angle of the central axis of the connecting pipe 212a with respect to the central axis Ai.

The magnitudes of the angles θ _L and θ _R may be changed according to the gripping positions of the left hand _HL and the right hand _HR . For example, as shown in FIG. 45, when the holding position of the manual air supply mechanism 211 is biased toward the operator side (lower side in the drawing) compared to the holding position of the grip 215 in the standard operation state, the operator's operation Considering ease of operation, the angle θ _L may be 60°±15° and the angle θ _R may be 45°±15°.

By arranging the grip 215 and the manual air supply mechanism 211 in this way, the apex of the grip 215 and the manual air supply mechanism 211 is near the left end of the pressure indicator 219 as seen from the operator in the standard operating state. It extends in an inverted V shape.
According to such an arrangement, in the standard operating state, it is easy to arrange the central axis Ai along the left-right direction of the operator or inclined at an acute angle with respect to the left-right direction.
In particular, if the pressure display window (display window 221a, which will be described later) in the pressure indicator 219 is formed long along the central axis Ai, the operator takes a posture in which the central axis Ai extends in the horizontal direction so that the display window can be easily seen. It is easy to be induced to

Next, the detailed shape of the pressure indicator 219 will be described.
FIG. 47 is a front view showing an example of a pressure indicator in a modified example (third modified example) of the air supply device. 48 is a bottom view of F48 in FIG. 47. FIG. 49 is a cross-sectional view taken along line F49-F49 in FIG. 47. FIG.

An example in which the outer shape of the pressure indicator 219 is cylindrical will be described below.
Regarding the shape of the pressure indicator 219 and the components included in the pressure indicator 219, axial, circumferential, and radial directions may be used based on the assembled configuration of the pressure indicator 219. FIG.
The axial direction is the direction along the center axis Ai. The circumferential direction is the direction of rotation around the center axis Ai. A radial direction is a direction along a line intersecting the central axis Ai on a plane perpendicular to the central axis Ai.
A position closer to the central axis Ai than a specific position on a half line extending radially from the central axis Ai may be referred to as radially inward of the specific position. Similarly, a position farther from the central axis Ai than a specific position may be referred to as being radially outward of the specific position.
Regarding the axial positional relationship with respect to the pressure indicator 219, the side closer to the third conduit P5 (the left side in FIG. 47) is called the proximal side, and the side farther from the third conduit P5 (the right side in FIG. 47) is called the distal side. sometimes referred to as The portion on the proximal side may be referred to as the proximal portion, and the portion on the distal side may be referred to as the distal portion. The most proximal portion is the proximal end and the most distal portion is the distal end.

As shown in FIGS. 47 and 48, the pressure indicator 219 has a case 220 (housing), a display window forming member 221, and a fixed frame 222. As shown in FIGS.
FIG. 47 shows the pressure indicator 219 placed in the same orientation as in FIG. Therefore, FIG. 47 shows the external shape seen by the operator in the standard operating state.
As shown in FIG. 49, the pressure indicator 219 further has a collar 223 (moving member), an airtight member 225 (sealing member, pressing member), and a coil spring 224 (elastic member) therein.

Case 220 has a bottomed cylindrical shape that forms the axial side surface and base end of pressure indicator 219 . A material for the case 220 is not particularly limited. For example, the material of case 220 may be resin, metal, glass, or a composite material in which two or more of these are combined. Case 220 is more preferably a resin molded product.
The parts of the overtube 301, including the case 220, may be drafted as required for manufacturing if molded. In the following description, for the sake of simplification, a shape ignoring the draft angle will be described. For example, a "cylindrical surface" includes an exact cylindrical surface and an approximate cylindrical surface that is drafted and inclined from a cylindrical surface.
The color of the case 220 is not particularly limited, but the region overlapping with the display window 221a, which will be described later, needs to be light transmissive. Only a portion of the case 220 that overlaps the display window 221a may be light transmissive. However, as for case 220, it is more preferred that the whole has light transmittance.

In the following, unless otherwise specified, an example in which the entire case 220 is made of a transparent resin material will be described. However, in FIG. 49, for the purpose of emphasizing that at least the region overlapping the display window 221a of the display window forming member 221, which will be described later, should have light transmittance when a part of the case 220 has light transmittance, Corresponding regions are indicated by alternating diagonal and dashed diagonal/dashed hatching. That is, in the following description, the portions hatched with diagonal lines in the illustration of the case 220 are also made of a transparent material like the portions marked with diagonal/broken lines. It represents that it may be used in the range of the portion hatched with oblique lines.
The kind of transparent resin material is not particularly limited. For example, resin materials suitable for the case 220 include polycarbonate, acrylic, and polysulfone.

As shown in FIG. 49, the case 220 has a bottom portion 220a, a side portion 220b (moving pipeline), a distal end frame 220c, and a connecting pipe 220d.
The bottom portion 220 a is a circular plate-like portion arranged at the base end of the case 220 .
The side surface portion 220b has a cylindrical shape extending axially from the outer peripheral portion of the bottom surface portion 220a toward the distal end side. Both the outer peripheral surface 220e and the inner peripheral surface 220f of the side surface portion 220b are cylindrical surfaces.
An engaging portion 220g for engaging an engaging claw 222e of a fixed frame 222, which will be described later, is provided at the tip of the side surface portion 220b.

The shape of the locking portion 220g is not particularly limited as long as it can lock the locking claw 222e. In the example shown in FIG. 49, the engaging portion 220g is formed by the inner peripheral portion of a rectangular hole penetrating through the side portion 220b in the thickness direction.
The number and arrangement of the engaging portions 220g are appropriately determined according to the number and arrangement of the engaging claws 222e, which will be described later. For example, in the examples shown in FIGS. 47 and 48, the locking portions 220g are provided one each around four positions that divide the side portion 220b into approximately equal quarters in the circumferential direction. Each locking portion 220g can lock one or more locking claws 222e.

The tip frame 220c is an annular frame formed coaxially with the side portion 220b at the tip of the side portion 220b. The outer diameter of the tip frame 220c is slightly larger than the outer diameter of the tip frame 220c. For this reason, a stepped portion extending radially outward is formed at the connecting portion between the side portion 220b and the tip frame 220c.
The same applies to the relationship between the inner diameter of the tip end frame 220c and the inner diameter of the side surface portion 220b.

The connection pipe 220d protrudes outside the case 220 from the center of the bottom surface portion 220a along the central axis Ai. The connection pipe 220d has an appropriate shape that can be connected to the end of the third pipeline P5.
In the main body portion 212C, the routes of the first pipeline P1 and the third pipeline P5 are not particularly limited, but in the example shown by the two-dot chain line in FIG. , to a first pipeline P1 extending from the lower side to the upper side in the drawing along the bottom surface portion 220a.
The first pipeline P1 is bent in a direction parallel to the central axis Ai at its lower end in the figure, and extends along the side portion 220b to substantially the center of the side portion 220b in the axial direction. Further, the first conduit P1 is bent along the angle of the connecting pipe 212a and connected to the connecting pipe 212a.

As shown in FIGS. 47 and 48, the display window forming member 221 is a film that is circumferentially wound along the outer peripheral surface 220e of the side portion 220b of the case 220 and fixed.
As a material of the display window forming member 221, a film having no light transmittance or low light transmittance is used.
A means for reducing the light transmittance of the display window forming member 221 is not particularly limited. For example, as the display window forming member 221, a film made of a coloring material with low light transmittance may be used. For example, as the display window forming member 221, a multilayer film in which an opaque layered portion is formed on the surface of a transparent base material may be used. For example, the opaque layered portion may be formed by printing, vapor deposition, lamination, laser processing, sticker application, or the like.

The outer shape of the display window forming member 221 is a rectangle elongated in the axial direction. That is, the display window forming member 221 is wound around the side surface portion 220b such that the longitudinal direction of the elongated rectangular film is along the circumferential direction.
The display window forming member 221 may cover the entire side surface 220b of the case 220, but in the example shown in FIGS. 47 and 48, it covers a part of the side surface 220b.
The display window forming member 221 covers the side surface portion 220b from a position on the distal end side of the center in the axial direction to near the proximal end of the case 220 in the axial direction. The display window forming member 221 covers an area longer than half of the entire circumference of the case 220 in the circumferential direction.
The display window forming member 221 is fixed to the side surface portion 220b by, for example, an adhesive or adhesive.

At the center of the display window forming member 221 in the circumferential direction (longitudinal direction) and near the tip in the axial direction (lateral direction), a display window 221a, which is an axially long rectangular opening, extends in the thickness direction. penetrates.
However, when the display window forming member 221 is formed of an opaque layered portion and a transparent base material, the hole passing through the opaque layered portion and the base material overlapping the hole also form the display window 221a. That is, the display window 221a may be optically opened.
The central axis of the display window 221a in the longitudinal direction overlaps with the central axis Ai in the front view shown in FIG.

A first scale line 221b (reference scale) and a second scale line 221c (reference scale) are formed inside the display window 221a and on the edge surrounding the display window 221a.
The first scale line 221b indicates, for example, the lower limit value of the proper internal pressure of the fixation balloon 3 .
The second scale line 221c indicates, for example, the upper limit value of the proper internal pressure of the fixation balloon 3 .
The first scale line 221b and the second scale line 221c may be formed integrally with the display window forming member 221, or may be formed after the display window forming member 221 is fixed to the side surface portion 220b.
In this modification, the first scale line 221b and the second scale line 221c are formed by printing or the like after fixing the display window forming member 221 to the side surface portion 220b. In this case, the positions of the first scale line 221b and the second scale line 221c can be formed based on the actually measured pressure display value by inspecting the assembled pressure indicator 219 or the like.

As shown in FIG. 49, the fixing frame 222 holds the tip of the airtight member 225 to be described later and fixes the position of the tip of the airtight member 225 . The fixed frame 222 is fitted inside a tip end frame 220 c that forms an opening at the tip of the case 220 . The fixed frame 222 is formed in a cylindrical shape with a bottom and arranged coaxially with the center axis Ai.
The fixed frame 222 has a bottom portion 222a, a first tubular portion 222f, a second tubular portion 222b, a locking claw 222e, and a flange portion 222c.

The bottom surface portion 222a is a disk having a diameter smaller than that of the bottom surface portion 220a. 222 d of through-holes are penetrated in the thickness direction in the center part of the bottom face part 222a.
The first cylindrical portion 222f forms a side portion of the fixed frame 222 on the base end side. The first tubular portion 222f extends axially from the outer periphery of the bottom surface portion 222a toward the distal end side. An outer peripheral surface 222g of the first tubular portion 222f is tapered slightly outward from the proximal end to the distal end.
The outer diameter of the outer peripheral surface 222 g is smaller than the inner diameter of the inner peripheral surface 220 f of the side surface 220 b of the case 220 . Between the outer peripheral surface 222g and the inner peripheral surface 220f of the side surface portion 220b, a gap is formed to sandwich the tip portion of the airtight member 225, which will be described later.

The second tubular portion 222b forms a side surface portion of the fixed frame 222 on the distal end side. The shape of the second cylindrical portion 222b is an annular shape connected to the tip of the first cylindrical portion 222f. The second tubular portion 222b fits inside the tip of the side surface portion 220b.
A locking claw 222e that locks onto the locking portion 220g of the case 220 is formed on the second tubular portion 222b. For example, the locking pawl 222e is elastically deformable in the radial direction and extends in the axial direction. A locking protrusion protruding radially outward is formed at the tip in the extending direction of the locking claw 222e.
For example, in the example shown in FIGS. 47 and 48, the locking claws 222e have one or two locking claws 222e centering on four positions that divide the second tubular portion 222b into approximately equal quarters in the circumferential direction, similarly to the locking portion 220g. are provided one by one.
The locking protrusion of the locking claw 222e penetrates into the hole of the locking claw 222e from the inner side of the side surface portion 220b and is locked to the inner surface of the locking portion 220g. As a result, the fixed frame 222 fitted in the case 220 is axially retained.

As shown in FIG. 49, the flange portion 222c extends radially outward from the tip of the side portion 220b. The shape of the flange portion 222c viewed from the axial direction is an annular shape as shown in FIG. The outer diameter of the flange portion 222 c is equal to the outer diameter of the tip end frame 220 c of the case 220 .
When the fixed frame 222 is fitted into the case 220 and the locking claws 222e are locked to the locking portions 220g, the flange portion 222c is in contact with the tip of the tip end frame 220c.
In this manner, the fixed frame 222 is fixed in axial and circumferential positions with respect to the case 220 while being fitted into the case 220 .

The collar 223 is provided so as to be axially movable inside the side surface portion 220b of the case 220 . In FIG. 49, the proximal end of the collar 223 is in contact with the bottom surface portion 220a of the case 220, and the collar 223 is arranged at the most proximal position in the movement range.
The outer shape of the collar 223 is cylindrical with a slightly smaller diameter than the inner peripheral surface 220f of the side surface 220b. Inside the collar 223, a base end portion of an airtight member 225, which will be described later, is inserted. A proximal end of the airtight member 225 is fixed to the collar 223 .
The collar 223 has an outer cylinder portion 223a (tubular portion), a locking plate 223b, a circular hole portion 223h, an angular groove portion 223i, a guide 223e, a fitting claw 223f, and a pressing claw 223g.

The outer cylindrical portion 223a is a cylinder with a slightly smaller diameter than the inner peripheral surface 220f of the side surface portion 220b. In the example shown in FIG. 49, the tips of the outer cylindrical portions 223a are aligned on the same plane perpendicular to the central axis Ai.
The tip of the outer cylindrical portion 223a circumferentially crosses the display window 221a as viewed from the outside within the range in which the collar 223 moves in the axial direction. A tip portion of the outer cylindrical portion 223a that crosses the display window 221a is referred to as a tip edge portion 223c. However, the tip edge portion 223c may protrude to the tip side from the tip of the outer cylindrical portion 223a, or may be recessed to the base end side.
In the collar 223, the vicinity of the tip edge portion 223c is colored with an appropriate color so that the operator can easily see it from the outside. For example, the collar 223 may be colored entirely including the leading edge portion 223c.

The locking plate 223b is a disk orthogonal to the central axis Ai. The locking plate 223b locks the base end of the airtight member 225, which will be described later. Especially in this modified example, the airtight member 225 is locked to the locking plate 223b and is detachably fixed to the locking plate 223b.
The locking plate 223b is provided inside the outer cylinder portion 223a near the proximal end of the outer cylinder portion 223a.

FIG. 50 is an exploded perspective view showing an example of a collar, a coil spring, and an airtight member in a modified example (third modified example) of the air supply device. FIG. 51 is a schematic diagram showing a fixing structure of an airtight member to a collar in a modified example (third modified example) of the air supply device. 52 is a cross-sectional view taken along line F52-F52 in FIG. 48. FIG.
As shown in FIG. 50, a circular hole 223h penetrates through the center of the locking plate 223b in the thickness direction. The circular hole portion 223h is formed coaxially with the center axis Ai.
A pair of square grooves 223i are formed by partially cutting out the locking plate 223b along the circular hole 223h. The square grooves 223i face each other in the radial direction of the circular hole 223h with the center of the circular hole 223h interposed therebetween.
An arc-shaped guide 223e extends toward the base end when viewed from the axial direction on the inner peripheral portion of the circular hole portion 223h excluding each square groove portion 223i.
As shown in FIG. 49, each guide 223e has a height that does not protrude beyond the proximal end of the outer cylindrical portion 223a.

A locking surface 223d, which is a surface on the front end side of the locking plate 223b, is provided with a pressing claw 223g having a hook-shaped cross section that protrudes toward the front end side and then bends toward the central axis Ai. A certain gap is formed between the tip of the pressing claw 223g and the locking plate 223b.
In this modification, since the collar 223 is formed by resin molding, a hole 223k for avoiding undercut penetrates through the locking plate 223b facing the tip of the pressing claw 223g.
As shown in FIG. 51, one presser claw 223g and one hole 223k are provided at each of four locations that divide the circumference around the center axis Ai into four equal parts.

As shown in FIG. 50, a pair of fitting claws 223f are provided on the base end side of the locking plate 223b.
As shown in FIG. 52, the fitting claw 223f has a hook-shaped cross section that protrudes toward the proximal end and then bends toward the central axis Ai. In the fitting claw 223f, a fitting projection 223m that protrudes toward the tip in the axial direction is formed at the tip of the hook. Between the fitting claw 223f and the locking plate 223b, a gap is formed in which a fitting projection 225b of the airtight member 225, which will be described later, is fitted.
In this modification, since the collar 223 is formed by resin molding, a hole 223j for avoiding undercut penetrates through the locking plate 223b facing the tip of the fitting claw 223f in the protruding direction. .
As shown in FIG. 51, the fitting claws 223f are provided one each at two locations facing each other in the radial direction across the center axis Ai. Each fitting claw 223f is formed on an axis Av perpendicular to the central axis Ai. A pair of pressing claws 223g facing each other in the radial direction are arranged on the axis Av with the fitting claws 223f interposed therebetween.
A central axis Ah extending in the facing direction of each square groove portion 223i is inclined 45° clockwise in the figure with respect to the axis Av.

As shown in FIG. 49 , the airtight member 225 is generally cup-shaped with an opening on the distal end side in the axial direction and an extendable length in the axial direction. The airtight member 225 is sandwiched between the collar 223 and the fixed frame 222 inside the case 220 .
The airtight member 225 is formed of a soft elastomer molding.
Examples of materials for the airtight member 225 include silicone rubber, urethane rubber, and nitrile rubber.
As shown in FIG. 50, the airtight member 225 includes a bottom plate portion 225c (second fixed portion), a boss portion 225a (second fixed portion), a fitting protrusion 225b, a bellows tube portion 225d, a flange portion 225e, and a sealing portion. 225f (first fixing portion).

The bottom plate portion 225 c is a flat plate perpendicular to the central axis Ai and provided at the base end portion of the airtight member 225 . Engagement projections 225i protrude radially outward from four positions on the outer periphery of the bottom plate portion 225c as seen from the axial direction, which equally divide the outer periphery into quarters in the circumferential direction.
As shown in FIGS. 49 and 52, each engaging projection 225i is inserted into the gap between the locking surface 223d of the collar 223 and the pressing claw 223g and engages with the collar 223 in the axial direction.
As shown in FIG. 50, the boss portion 225a is formed such that the central portion of the bottom plate portion 225c protrudes toward the base end side in the axial direction. The outer shape of the boss portion 225a seen from the axial direction is circular. The boss portion 225a is fitted to the circular hole portion 223h of the collar 223 and the inner peripheral surface of the guide 223e so as to be rotatable around the central axis Ai.

As shown in FIG. 52, the fitting protrusion 225b is a plate that protrudes parallel to the bottom plate portion 225c from the side surface of the boss portion 225a. The projection amount and thickness of the fitting protrusion 225b are such that they fit into the gap between the locking plate 223b and the fitting claw 223f.
A fitting groove 225h into which the fitting projection 223m of the pressing claw 223g fits is formed on the surface of the fitting projection 225b on the base end side.
The fitting groove 225h extends in the circumferential direction along the track along which the fitting protrusion 223m rotates around the center axis Ai.
The fitting projections 225b are provided at two locations facing each other in the radial direction across the center axis Ai.

The bellows tube portion 225d extends from the outer peripheral portion of the bottom plate portion 225c, excluding the engaging projection 225i, toward the distal end side in the axial direction. The radially outer diameter of the bellows tube portion 225d is smaller than the diameter of the circumference where the radial ends of the engaging projections 225i are located.
Now, with reference to FIG. 53, a detailed cross-sectional shape of the bellows tube portion 225d will be described.
53 is an enlarged view of the F53 portion in FIG. 52. FIG.

A bellows tube portion 225d shown in FIG. 53 has a shape in a natural state where no external force acts in the axial direction. Unless otherwise specified, the bellows tube portion 225d in its natural state will be described below. The bellows tube portion 225d may be assembled to the pressure indicator 219 in a more compressed state than in its natural state, but will be described below with the collar 223 moved most proximally as shown in FIG. , an example in which the bellows tube portion 225d is in a natural state.

The bellows tube portion 225d has a tapered shape that is inclined with respect to a plane perpendicular to the central axis Ai, and has an annular thin portion 225t when viewed from the axial direction. The thin portions 225t are arranged so that the inclination thereof alternates in the axial direction, and adjacent thin portions 225t are connected to each other at the inner peripheral portion and the outer peripheral portion.
The inner peripheral portion is connected by a bent portion 225s, and the outer peripheral portion is connected by a thick portion 225n.

The outer peripheral surface of the bellows tube portion 225d is an uneven surface in which a first outer slope 225k, a first outer surface 225j, a second outer slope 225m, and a second outer surface 225u repeat in the axial direction.
The first outer slope 225k is inclined radially outward from the base end side (left side in the figure) in the axial direction toward the tip end side (right side in the figure).
The first outer surface 225j is a cylindrical surface extending from the radially outer end of the first outer slope 225k toward the tip side in the axial direction. The first outer surface 225j forms the outermost outer surface of the bellows tube portion 225d.
The second outer slope 225m inclines radially inward from the tip of the first outer side surface 225j toward the tip side.
The second outer surface 225u is a cylindrical surface extending from the radially inner end of the second outer slope 225m toward the tip side in the axial direction.

The inner peripheral surface of the bellows tube portion 225d is an uneven surface in which the first inner slope 225q, the first inner surface 225p, the second inner slope 225r, and the second inner surface 225v repeat in the axial direction.
The first inner slope 225q has a distance of tn from the first outer side surface 225j in the thin portion 225t. The first inner slope 225q also forms a surface on the tip side in the axial direction of the bent portion 225s.
The first inner surface 225p forms the inner peripheral surface of the thick portion 225n. The radial distance between the first inner surface 225p and the first outer surface 225j is Dk.
The second inner slope 225r inclines radially inward from the tip of the first inner side surface 225p toward the tip side.
The second inner surface 225v is a cylindrical surface in the axial direction from the radially inner end of the second inner slope 225r.

The thick portion 225n is a circle formed by rotating a trapezoidal cross section surrounded by the first outer slope 225k, the first outer side surface 225j, the second outer slope 225m, and the first inner side surface 225p around the central axis Ai. It is an annulus.
The first width (maximum thickness in the axial direction) of the thick portion 225n in the axial direction along the center axis Ai is Wk, and the second width (first inner surface 225p and the first outer surface 225j) is Dk.
The angle formed by the adjacent thin portions 225t in a cross section including the central axis Ai is φ. The pitch of the bellows shape of the bellows tube portion 225d in the axial direction is defined by the pitch Pb of the center in the thickness direction of the thick portion 225n in the natural state where the bellows tube portion 225d is not deformed by an external force.

The thick portion 225n in this modified example is formed for the purpose of suppressing buckling of the thin portion 225t due to an external force directed radially inward from the outer peripheral portion. If the rigidity of the thick portion 225n is appropriate, the deformation of the thick portion 225n in the radial direction due to an external force is suppressed, so that the thin portion 225t is less likely to buckle. For example, the average thickness of the thin portion 225t may be 0.3 mm or more and 0.7 mm or less.
For example, the first width Wk of the thick portion 225n in the axial direction is three times or more the thickness tn (average thickness) of the thin portion 225t and two-thirds or less of the pitch Pb of the bellows tube portion 225d. is more preferable.
For example, the second width Dk of the thick portion 225n in the radial direction is more preferably three times or more the thickness tn of the thin portion 225t. However, even if Dk is made too large, the resistance to the external force in the radial direction is not improved so much, so it is more preferable to set Dk to about 3.1 mm or less, for example.
It is preferable that the angle φ between the thin portions 225t be as small as possible within a range in which formability is not deteriorated. For example, the angle φ is measured by the angle between the second outer slope 225m and the first outer slope 225k that form the V-shaped recess. Therefore, the angle φ is the angle of the valley formed by the thin portion 225t.
Since the rigidity of the bent portion 225s does not significantly affect the buckling of the thin portion 225t, the axial width of the bent portion 225s may be thinner than the thick portion 225n. For example, the axial width of the second outer surface 225u may be zero. The width of the second inner slope 225r may be zero if the formability does not deteriorate.

In this modification, in the natural state of the airtight member 225, the first outer slope 225k and the second outer slope 225m are tapered surfaces having a common slope in both the thick portion 225n and the thin portion 225t.
Similarly, the first inner slope 225q and the second inner slope 225r are tapered surfaces having a common slope at both the bent portion 225s and the thin portion 225t.
Therefore, when the airtight member 225 is formed by resin molding, the outer peripheral surface of the airtight member 225 is transferred with the shape of the molding die Mo in which convex portions and concave portions having a trapezoidal cross section appear alternately in the axial direction. The inner peripheral surface of the airtight member 225 has the shape of the mold Mi in which convex portions and concave portions having a trapezoidal cross-sectional shape appear alternately in the axial direction is transferred.
In this way, no steps or discontinuous inclined surfaces are formed between the thick portion 225n and the thin portion 225t and between the bent portion 225s and the thin portion 225t, so that moldability is improved. . Furthermore, molding is facilitated in that the molded product is less likely to be removed from the molding dies Mo and Mi when demolded.

[Table 1] below shows shape examples 1 to 3 of the bellows tube portion 225d.
In [Table 1], dimensions other than those described above are as follows.
Dd represents the average diameter of the bellows tube portion 225d. Dd is obtained from the average of the diameter of the first inner surface 225p and the diameter of the second inner surface 225v.
du is the depth of the valley formed by the thin portion 225t, that is, the radial distance from the first inner surface 225p to the second outer surface 225u.

In shape examples 1 to 3, by changing the specifications according to the rubber hardness (Shore A), an appropriate shape of the thick portion 225n that suppresses the buckling of the thin portion 225t is realized.
In shape examples 1 to 3, Wk is 2.5 mm, 2.3 mm and 2.3 mm, and tn is 0.5 mm, 0.7 mm and 0.7 mm. That is, Wk/tn is 5.0.3, 3, and 3.3, respectively, so Wk is more than three times tn.
In Shape Examples 1 to 3, ⅔ of the pitch Pb is 2.9, so Wk is ⅔ or more of Pb.
In shape examples 1 to 3, Dk is 3.0 mm, and three times tn is 1.5 mm, 2.1 mm, and 2.1 mm, respectively. Therefore, Dk is three times or more of tn and 3.1 mm or less.

The larger the average diameter Dd, the smaller the resistance when contracting the bellows tube portion 225d in the axial direction, and the better the moldability. On the other hand, the rigidity in the radial direction required to suppress buckling in the radial direction of the thin portion 225t increases.
The larger the angle φ, the better from the standpoint of formability. On the other hand, as φ increases, the drag increases and the required radial stiffness decreases.
The deeper the valley depth du, the more the drag decreases. On the other hand, radial stiffness and moldability are reduced.
If the pitch Pb of the bellows tube portion 225d is large, the resistance increases and the rigidity in the radial direction decreases. On the other hand, moldability is improved.
As the axial width Wk of the thick portion 225n increases, the drag increases. On the other hand, radial stiffness and moldability are improved.

As shown in FIG. 49, the flange portion 225e extends radially outward from the tip of the bellows tube portion 225d in the axial direction. The outer diameter of the flange portion 225e is smaller than the inner diameter of the side surface portion 220b of the case 220 and larger than the outer diameter of the coil spring 224 described later.

The sealing portion 225f has a cylindrical shape extending axially from the outer circumference of the flange portion 225e toward the distal end side. The sealing portion 225f is sandwiched between the inner peripheral surface 220f of the side surface portion 220b and the outer peripheral surface 222g of the first cylindrical portion 222f of the fixed frame 222. As shown in FIG.
The inner peripheral surface of the sealing portion 225f is a cylindrical surface that can be in close contact with the outer peripheral surface 222g.
The outer peripheral surface of the sealing portion 225f is provided with a protrusion 225g that protrudes radially outward and extends along the entire circumference of the outer peripheral surface. In the example shown in FIG. 49, the ridges 225g are formed one by one at two locations separated in the axial direction.
The distance in the radial direction between the inner peripheral surface of the sealing portion 225f and the top of the protrusion 225g is greater than the gap between the inner peripheral surface 220f and the outer peripheral surface 222g. For this reason, when the sealing portion 225f is sandwiched between the inner peripheral surface 220f and the outer peripheral surface 222g, the inner peripheral surface of the sealing portion 225f moves toward the first tubular portion 222f while the protrusion 225g is pressed in the radial direction. Closely with. As a result, the gap between the tip of the side surface portion 220b and the fixed frame 222 is sealed in an airtight and liquid-tight manner.

The through hole 222d in the fixed frame 222 is open facing the inside of the bellows tube portion 225d. Therefore, the inside of the bellows tube portion 225d communicates with the outside through the through hole 222d.

As shown in FIG. 50, coil spring 224 is a compression coil spring. The coil spring 224 may be made of metal, or may be made of a highly elastic resin material.
As shown in FIG. 49, the inner diameter of the coil spring 224 is larger than the outer diameter of the bellows tube portion 225d, and is large enough to surround the pressing claw 223g from the outside in the radial direction. Furthermore, the outer diameter of the coil spring 224 is smaller than the inner diameter of the outer cylindrical portion 223a of the collar 223 and approximately the same as the outer diameter of the bottom surface portion 222a of the fixed frame 222.
Therefore, each end of the coil spring 224 in the axial direction is locked to the locking surface 223d of the collar 223 and the flange portion 225e of the airtight member 225, respectively. In this modification, the flange portion 225e is axially held by the tip of the coil spring 224 and the bottom portion 222a.

Since the coil spring 224 is compressed when the collar 223 moves axially distally, it urges the collar 223 axially proximally.
The spring constant of the coil spring 224 is set so that the pressure inside the case 220 can be displayed in the display window 221a according to the amount of movement of the collar 223 .
The coil spring 224 is not limited to a coil spring as long as it can bias the collar 223 toward the base end. A suitable elastic member that generates a biasing force may be used as the coil spring 224 .

Here, the fixing structure between the tip portion of the airtight member 225 and the collar 223 will be described.
As shown in FIGS. 49 and 51, the airtight member 225 fixed to the collar 223 is radially positioned by inserting the boss 225a into the circular hole 223h and the guide 223e.
As shown in FIG. 52, each engaging protrusion 225i is inserted between the locking surface 223d and the pressing claw 223g. Further, each fitting projection 225b is fitted between the proximal surface of the locking plate 223b and the fitting claw 223f. Thereby, the locking plate 223b is fixed to the tip portion of the airtight member 225 while being sandwiched between each engaging projection 225i and each fitting projection 225b.

In order to form such a fixed structure, in FIG. 50, the airtight member 225 is rotated 45 degrees in the direction of arrow K indicated by a two-dot chain line around the central axis Ai, and the inner side of the coil spring 224 and the outer side of the collar 223 are fixed. It is inserted inside the cylindrical portion 223a. At this time, when the bottom plate portion 225c abuts against the locking surface 223d, the fitting protrusion 225b passes through the inside of the square groove portion 223i. At this time, the front end side surface of the fitting projection 225b reaches substantially the same position as the base end side surface of the locking plate 223b.
In this state, when the airtight member 225 is rotated 45 degrees in the direction opposite to the arrow K, the boss 225a is guided along the circular hole 223h and the guide 223e.
As the rotation progresses, each engaging projection 225i engages with the pressing claw 223g and each fitting projection 225b engages with the fitting claw 223f. In particular, since the fitting groove 225h into which the fitting projection 223m is fitted is formed in the fitting projection 225b, the rotation center of the airtight member 225 during rotation of the airtight member 225 is easily aligned with the center axis Ai. .
Sealing member 225 is thus secured to collar 223 by member-to-member engagement formed by axial translational movement and circumferential rotational movement relative to collar 223 . Since the airtight member 225 is made of a soft elastomer, the engagement position is stabilized by friction with the collar 223 after engagement.
According to this modification, for example, the airtight member 225 can be fixed without using screws, adhesives, or the like, thereby reducing the cost of parts and facilitating manufacturing.

Next, the operation of this modified example will be described with a focus on the operation and action of the pressure indicator 219. FIG.
FIG. 54 is a schematic cross-sectional view showing the operation of the pressure indicator in the modified example (third modified example) of the air supply device. 55 is a view from F55 in FIG. 54. FIG.

When the operator operates the manual air supply mechanism 211 to supply air, air flows into the case 220 through the third conduit P5 as indicated by the arrow shown in FIG. The case 220 is airtightly sealed by an airtight member 225 fixed to the tip of the side portion 220b by a fixing frame 222. As shown in FIG.
The internal space of the case 220 sealed by the airtight member 225 is roughly divided into a first space S1 on the proximal side of the locking plate 223b of the collar 223 and a second space S2 on the distal end side. . However, the first space S1 and the second space S2 communicate with each other through various gaps. Examples of various gaps include a gap between the outer cylindrical portion 223a and the side portion 220b, and gaps in the holes 223j and 223k that are not blocked by the airtight member 225. FIG.
On the other hand, the third space S3 inside the airtight member 225 does not communicate with the first space S1 and the second space S2, but communicates with the outside through the through hole 222d.
Therefore, the internal pressure pi of the air flowing into the first space S<b>1 and the second space S<b>2 acts on the inner peripheral surface of the case 220 and the outer peripheral surface of the airtight member 225 .

The airtight member 225 has a bellows tube portion 225d that is easily stretchable in the axial direction. The stiffness in the axial direction of the bellows tube portion 225d is smaller than the stiffness in the radial direction. The bellows tube portion 225d contracts in the axial direction according to the axial resultant force of the internal pressure pi acting through the boss portion 225a and the locking plate 223b. As a result, the collar 223 moves axially toward the distal end.
The collar 223 moves in the axial direction so that the resultant force of the internal pressure pi in the axial direction and the resultant force of the biasing force of the coil spring 224 and the atmospheric pressure po acting in the axial direction are balanced. As a result, the first space S1 expands and the second space S2 contracts.
By investigating the relationship between the spring constant of the coil spring 224 and the internal pressure of the case 220 in advance, the position of the collar 223 and the internal pressure pi within the case 220 can be associated one-to-one.

In this modification, the tip edge portion 223c of the collar 223 can be seen through the display window 221a, so the operator can visually recognize the position of the collar 223 representing the internal pressure pi by the position of the tip edge portion 223c.
For example, as shown in FIG. 55, when the tip edge portion 223c is between the first scale line 221b and the second scale line 221c, the operator knows that the internal pressure of the fixation balloon 3 is in a proper state. can know

The first space S1 and the second space S2 in this modified example have the same function as the first space Sa of the pressure adjusting section 217A in the second modified example. For this reason, the pressure indicator 219 is an example of an enlarged diameter portion that changes in volume in the second modification.

In this modification, by providing the thick portion 225n in the bellows tube portion 225d, the radial rigidity of the airtight member 225 is greater than the axial rigidity thereof.
The action of the thick portion 225n will be described with reference to a comparative example.
FIG. 56 is a schematic cross-sectional view showing a comparative example of an airtight member with a bellows structure deformed by pressure.

The bellows tube portion B of the comparative example shown in FIG. 56 is formed of an elastomer film having the same thickness tn as the thin portion 225t of the bellows tube portion 225d of this modified example. The bellows tube portion B is bent in an inverted V shape at the mountain fold portion on the outer periphery. However, since the bellows tube portion B is formed with a uniform thickness, the outer peripheral portion of the bellows tube portion B is not formed with a thick portion as in this modified example.
The mountain-folded portion in FIG. 56 is schematically drawn in an inverted V shape with no roundness in the bend. However, in the bellows tube portion B, the corners at the tips of the mountain folds are rounded so that the average thickness is maintained so as to improve moldability.

Since the bellows tube portion B has a low rigidity in the radial direction at the outer peripheral portion, when the internal pressure of the second space S2 acts in the radial direction, the mountain-folded portion of the outer peripheral portion buckles inward to form a trough, as shown at F56. It will be folded. As a result, the radial rigidity of the bellows tube portion B is increased, and the collar 223 is less likely to move toward the distal end. Furthermore, the internal pressure pi is reduced in that the volume of the second space S2 is expanded by bending the bellows tube portion B inward.
As a result, the amount of movement of the collar 223 does not accurately indicate the internal pressure pi.
On the other hand, in this modified example, since the thick portion 225n is formed, the bellows tube portion 225d does not undergo buckling deformation inward, so the pressure indicator 219 can display an accurate pressure.

Even if the pressure indicator 219 can accurately display the pressure, the pressure display may not be read accurately depending on the viewing direction of the operator.
FIG. 57 is a schematic cross-sectional view explaining a reading error in a pressure indicator in a modified example (third modified example) of the air supply device.
FIG. 57 shows a cross section along the axial direction when the tip edge portion 223c has moved to the position of the first scale line 221b.
When the viewing direction of the operator is represented by an arrow V0 that coincides with the radial direction, the operator can accurately read that the tip edge portion 223c has reached the first scale line 221b.
For example, when the viewing direction of the operator is indicated by an arrow V1 inclined toward the proximal side with respect to the radial direction, the distal edge portion 223c appears to be located on the proximal side by Δ1 to the first scale line 221b. Similarly, when the viewing direction of the operator is indicated by an arrow V2 inclined toward the distal side with respect to the radial direction, the distal edge portion 223c appears to be positioned Δ2 distal to the first scale line 221b.

In this modified example, as shown in FIG. 45, the grip 215 and the manual air supply mechanism 211 are arranged in an inverted V shape. As a result, in the standard operating state, the center axis Ai substantially coincides with the left-right direction of the operator. The display window 221a is elongated in the axial direction along the center axis Ai, and the tip edge portion 223c in the display window 221a extends in the direction perpendicular to the center axis Ai. Therefore, the tip edge portion 223c extends in the vertical direction of the operator's visual field in front of the operator in the standard operation state.
Therefore, when reading the pressure, the operator places the display window 221a in the center of the front of the body so that it can be easily seen. As a result, the viewing direction of the operator becomes the direction of the arrow V0.
At this time, even if the arrow V0 is inclined in the circumferential direction with respect to the normal direction of the side surface portion 220b, the viewing direction is only inclined in the direction in which the tip edge portion 223c extends. do not have.

On the other hand, consider a configuration in which the axial direction of the pressure indicator 219 is installed in the vertical direction of the visual field of the operator, or the tip edge portion 223c is moved in the vertical direction.
In this case, even if the display window is placed in front of the operator in the standard operation state, the operator must look at the display window from directly above to see the direction of arrow V0. Generally, in the standard operating state, the left hand _HL and the right hand _HR are positioned considerably below the operator's face, so the operator's viewing direction is guided in the directions of arrows V1 and V2, for example.
As a result, the operator's reading error increases, and the effects of this modified example cannot be obtained.

An overtube 201 having an air supply device 210C of this modification is the same as the overtube 201 except that it has an air supply device 210C instead of the air supply device 210 of the overtube 201 according to the third embodiment. is. Therefore, according to this modified example, as in the third embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this modified example, instead of the pressure adjusting portion 217 in the second modified example, a pressure indicator 219, which is an example of an enlarged diameter portion whose volume changes like the pressure adjusting portion 217, is provided. Therefore, this modified example has the same effect as the second modified example.
Furthermore, according to this modification, the pressure indicator 219 displays the pressure inside the case 220 by the position of the tip edge portion 223c with respect to the first scale line 221b and the second scale line 221c. As a result, the operator can determine when to stop the air supply operation by considering the resistance of the manual air supply mechanism 211 and the pressure display in the display window 221a. As a result, loss of air supply is further reduced.

According to this modification, since the bellows tube portion 225d of the airtight member 225 has the thick portion 225n, the airtight member 225 smoothly expands and contracts in the axial direction without collapsing in the radial direction. As a result, the correspondence between the internal pressure pi and the position of the tip edge portion 223c seen through the display window 221a becomes accurate.

According to this modification, in the standard operation state, the tip edge portion 223c extends in the vertical direction of the field of view of the operator. Errors in reading pressure readings are reduced.

The pressure indicator 219 in the air supply device 210C is connected to the first conduit, has a flow path having a flow path cross-sectional area larger than that of the first conduit, and measures the pressure of the first conduit. It is an example of a pressure indicator to display.
The first space S1 in the pressure indicator 219 forms a channel through which air flows, and has a channel cross-sectional area larger than that of the first conduit P1.
In the pressure indicator 219, the case 220 is an example of a housing at least partially provided with a display window 221a through which the inside can be seen. In the pressure indicator 219, the collar 223 is an example of a moving member that moves within the housing according to the pressure inside the housing and whose movement position can be observed through the display window.
In the pressure indicator 219, the first scale line 221b and the second scale line 221c are formed around the display window or around the display window, and are examples of reference scales indicating the pressure according to the position of the moving member.

The airtight member 225 in the pressure indicator 219 is an example of a sealing member that airtightly seals an opening formed at the end of the housing in the moving direction of the moving member.
The sealing portion 225f of the airtight member 225 is an example of a first fixing portion airtightly fixed to the end of the housing. The bellows tube portion 225d of the airtight member 225 is an example of a bellows tube portion that extends from the first fixed portion toward the moving member and has a bellows shape that can be expanded and contracted in the moving direction on the side surface.
The boss portion 225a and the bottom plate portion 225c of the airtight member 225 close the end of the bellows tube portion in the extending direction, and are an example of a second fixing portion fixed to the moving member.
The thin portion 225t of the airtight member 225 forms part of the side surface of the bellows tube portion, and is an example of an inclined surface portion arranged in an inverted V shape tapering radially outward in a cross section including the central axis of the bellows tube portion. is.
The thick portion 225n of the airtight member 225 is formed thicker than the average thickness of the inclined surface portions, and is an example of a thick portion that airtightly closes the outer peripheral portions of the inclined surface portions forming an inverted V shape.

A body portion 212 included in the air supply device 210C is an example of a body portion provided with a pressure indicator and connected to a manual pump.
The grip 215 is an example of a grip that extends in a direction that intersects the central axis of the manual pump connected to the main body and that is arranged to form an inverted V shape with the central axis.
In the body portion 212, the central axis of the manual pump and the extending direction of the gripping portion form an acute angle with respect to the moving direction of the moving member. located in

[Fourth Modification]
A modification (fourth modification) of the air supply device used in place of the air supply device 210 in the overtube 201 of the third embodiment will be described.
As shown in FIG. 17, an air supply device 210D of this modification can be used in place of the air supply device 210 of the overtube 201. As shown in FIG.
FIG. 58 is a schematic front view showing a modification (fourth modification) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention. FIG. 60 is a schematic cross-sectional view showing an exploded state of a modified example (fourth modified example) of the air supply device. 61 is a cross-sectional view taken along line F61-F61 in FIG. 59. FIG. 62 is a cross-sectional view taken along line F62-F62 in FIG. 61. FIG.

As shown in FIG. 58, the air supply device 210D has a body portion 212D instead of the body portion 212 of the air supply device 210. As shown in FIG.
The body portion 212D has a pressure display portion 219D, a body case 230, and a display window forming member 221D.
In the following, differences from the third embodiment and the third modified example will be mainly described.

As shown in FIG. 59, the pressure display portion 219D is the same as the portion of the pressure display 219 except for the case 220 in the third modification.
The main body case 230 has the same outer shape as the body part 218 and the side part 220b of the case 220 in the third modification.
Like the case 220 in the third modified example, the main body case 230 has a light transmissive property at least in a region overlapping a portion where a display window 221a is formed by a display window forming member 221D, which will be described later. For this reason, a part of the main body case 230 may have a portion that does not have optical transparency. In the following, an example in which the main body case 230 is entirely made of a transparent resin material will be described.
The body case 230 has a grip 215, a relief valve 213, a connection pipe 212a, and an air pipe 210a similar to the third modification.
Further, inside the main body case 230, there is provided an accommodating portion 230a and a buffer portion 230b.

The accommodation portion 230a accommodates the pressure display portion 219D. The housing portion 230a has the same shape as the side portion 220b of the case 220 in the third modification, except that it protrudes outward from the connecting tube 212a like the housing portion 218 in the third modification.
Below, the central axis of the cylindrical portion of the accommodating portion 230a is referred to as the central axis line Ai as in the third modification. The usage of axial, radial, and circumferential directions with respect to the central axis Ai is similar.
The connecting pipe 212a in this modified example opens inside the housing portion 230a at a position where it is not closed by the movement of the collar 223 in the pressure display portion 219D.
The opening at the tip of the housing portion 230a is formed by the tip frame 220c, similarly to the side portion 220b. A locking portion 220g is formed at the tip of the housing portion 230a, similarly to the side portion 220b.

The outer peripheral surface of the housing portion 230a is an outer peripheral surface 220e similar to the side surface portion 220b. A display window forming member 221D substantially similar to the display window forming member 221 is attached to the outer peripheral surface 220e of the housing portion 230a.
The display window forming member 221D is the same as the display window forming member 221 in the third modified example, except that it is provided in a shape that avoids the connection pipe 212a projecting from the accommodating portion 230a. The shape that avoids the connecting pipe 212a is not particularly limited, but for example, in the example shown in FIG.

A buffer portion 230b having a channel cross-sectional area larger than the channel cross-sectional area of the connecting pipe 212a is provided at the base end portion of the housing portion 230a.
The buffer unit 230b holds a certain volume or more of the air that has flowed from the connecting tube 212a by the operator's air supply operation, with the pressure reduced.
The buffer portion 230b is formed with an opening 230c at the connection portion with the accommodating portion 230a. The opening 230c opens axially. The opening 230c has a cylindrical shape with a smaller diameter than the inner peripheral surface 220f of the housing portion 230a and a smaller diameter than the outer cylindrical portion 223a of the collar 223 .

A pressure display portion 219D is inserted into the accommodation portion 230a. As shown in FIGS. 59 and 61, the fixing frame 222 in the pressure display portion 219D is locked to the locking portion 220g of the accommodating portion 230a by the locking claws 222e similar to the third modified example. Thereby, the axial and circumferential positions of the pressure display portion 219D with respect to the accommodating portion 230a are fixed.
In such an assembled state, the collar 223 can move in the axial direction inside the accommodating portion 230a as in the third modification.

As shown in FIG. 61, the buffer portion 230b has an inner peripheral surface 230d whose channel cross-sectional area decreases with distance from the accommodating portion 230a in the axial direction.
As shown in FIG. 60, the inner peripheral surface 230d extends inside the grip 215. As shown in FIG. An attachment portion 230e for the relief valve 213 and the air supply pipe 210a are opened at the upper portion of the inner peripheral surface 230d.

As shown in FIG. 62-4, when looking at the collar 223 of the pressure display portion 219D from the inside of the buffer portion 230b, the locking plate 223b has an outer cylindrical portion 223a and a housing portion 230a, as in the third modification. A gap between them and a gap not covered by the engaging protrusion 225i are formed in each hole 223k. These gaps allow the space surrounded by the housing portion 230a and the outer peripheral portion of the airtight member 225 and the space inside the buffer portion 230b to communicate with each other.

The airtight member 225 in the pressure display portion 219D seals the internal space of the body case 230 on the tip side of the housing portion 230a. As a result, the inside of the body case 230 is divided into a first space S _A surrounded by the body case 230 and the bellows tube portion 225 d and a second space S _B inside the airtight member 225 .
Air flows into the first space _SA from the connection tube 212a by the operator's air supply operation.
The second space SB communicates with the outside air through the through hole _222d and is kept at atmospheric pressure.
The volumes of the first space S _A and the second space S _B change due to the movement of the collar 223 and the expansion and contraction of the airtight member 225 due to the internal pressure of the first space S _A .

With such a configuration, as indicated by an arrow in FIG. 59, the air flowing into the connection pipe 212a enters the first space SA outside the bellows tube portion _225d inside the accommodating portion 230a. The air passes through the gap of the hole _223k or the gap outside the outer cylindrical portion 223a toward the first space SA within the buffer portion 230b. The air that has flowed into the buffer portion 230b moves the collar 223 in the axial direction according to the internal pressure of the first space _SA , and part of it flows out of the main body case 230 from one or both of the air supply pipe 210a and the relief valve 213. exhausted.
The tip edge portion 223c of the collar 223 displays the internal pressure of the first space SA in the display window 221a of the display window forming member _221D , as in the third modification.
Therefore, the accommodation portion 230a, the buffer portion 230b, and the pressure display portion 219D form a pressure display PI (see FIG. 58) similar to that of the third modification.

The internal flow path in such main body case 230 can be represented schematically as shown in the block diagram of FIG.
FIG. 63 is a block diagram showing a modified example (fourth modified example) of the air supply device.
As shown in FIG. 63, the first space SA forms an enlarged diameter portion P7 having a flow passage cross _- sectional area larger than that of the first pipeline P6 formed by the connecting pipe 212a. The volume of the enlarged diameter portion P7 changes according to the internal pressure.
A relief valve 213 and an air pipe 210a are connected to the enlarged diameter portion P7. The air pipe 210a in this modified example forms a second pipe line P8 having a flow passage cross-sectional area smaller than that of the enlarged diameter portion P7.

The configuration of this modified example corresponds to replacing the enlarged diameter portion P4 in the first modified example with an enlarged diameter portion P7 whose volume changes.

An overtube 201 having an air supply device 210D of this modification is the same as the overtube 201 except that it has an air supply device 210D instead of the air supply device 210 of the overtube 201 according to the third embodiment. is. Therefore, according to this modified example, as in the third embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this modification, since the same pressure indicator PI as the pressure indicator 219 in the third modification is provided, pressure can be displayed in the same manner as in the third modification. Therefore, this modified example has the same effect as the third modified example.
According to this modified example, as in the first modified example, the relief valve 213 is provided in the expanded diameter portion P7 whose volume changes, so that it has the same effect as the first modified example.

Furthermore, according to this modification, the main body case 230 is formed by integrating the side surface portion 220b and the housing portion 218 of the third modification. Therefore, compared to the third modification, the number of parts is reduced, so the part cost and assembly cost are reduced.
The structure is simpler than that of the third modified example because no pipe line for forming a flow path is provided inside main body case 230 .

[Fifth Modification]
A modification (fifth modification) of the air supply device used in place of the air supply device 210 in the overtube 201 of the third embodiment will be described.
As shown in FIG. 17, an air supply device 210E of this modified example can be used in place of the air supply device 210 of the overtube 201. As shown in FIG.
As shown in FIG. 45, an air supply device 210E has a pressure indicator 219E instead of the pressure indicator 219 of the third modified example.
As shown in FIG. 49, a pressure indicator 219E is the same as the pressure indicator 219 except that it has an airtight member 225E (sealing member, pressing member) instead of the airtight member 225 of the third modified example. be.
In the following, differences from the third embodiment and the third modified example will be mainly described.

FIG. 64 is a schematic cross-sectional view showing an example of an airtight member used in a modified example (fifth modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention. FIG. 64(a) is a cross-sectional view showing the shape of the airtight member 225E in a natural state where no external force acts in the axial direction. Similarly, (b) is a cross-sectional view showing a state in which the airtight member 225E is attached to the pressure indicator 219E.

As shown in FIG. 64, an airtight member 225E in this modified example has a configuration similar to that of the airtight member 225. As shown in FIG. However, in the natural state, the length (outer dimension) Ln from the bottom plate portion 225c to the flange portion 225e in the axial direction is longer than the maximum distance (inner dimension) Ls from the locking plate 223b to the bottom surface portion 222a in the pressure indicator 219E. long.
As a result, when the airtight member 225E is attached to the pressure indicator 219E, the airtight member 225E is axially compressed.

By compressing the airtight member 225E in the axial direction, the angle formed by the thin portions 225t adjacent to each other is shallower than in the natural state.
For example, as shown in (a) of FIG. 64, in a thin portion 225t forming a mountain shape protruding outward, the angle formed by the first outer slope 225k and the second outer slope 225m is θo, and the first inner slope 225q and the second inner slope 225r is θi.
The angles .theta.o and .theta.i are appropriate angles that do not cause the mold to be removed during molding. For example, the angles θo and θi are more preferably equal to each other, but may be different from each other.
The greater the angles θo and θi, the easier the molding. For example, the angles θo and θi are desirably 20° or more.

As shown in FIG. 64(b), when the airtight member 225E is attached, the angle formed by the first outer slope 225k and the second outer slope 225m is φo (where φo<θo) and the first The angle between the inner slope 225q and the second inner slope 225r is φi (where φi<θi).
As described in the third modified example, the smaller the angle φ corresponding to φo and φi, the better the radial rigidity of the bellows tube portion 225d.

In this modified example, the airtight member 225E is formed in a shape in which the thin portions 225t form a large angle, so that the formability of the airtight member 225E is improved.
In this modification, the airtight member 225E is axially compressed when the pressure indicator 219E is attached to the airtight member 225E. The angle formed by the thin portions 225t becomes smaller than in the natural state, and the rigidity in the radial direction increases. Thereby, the pressure indicator 219E can display an accurate pressure like the 3rd modification.
The airtight member 225E is axially compressed, and the elastic restoring force due to deformation increases the resistance against the movement of the collar 223 to some extent. However, since the relationship between the internal pressure of the case 220 and the movement position of the collar 223 is associated with the deformed state of the airtight member 225E, the pressure indicator 319E can display the pressure accurately.

An overtube 201 having an air supply device 210E of this modified example is the same as the overtube 201 except that it has an air supply device 210E instead of the air supply device 210 of the overtube 201 according to the third embodiment. is. Therefore, according to this modified example, as in the third embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this modified example, similarly to the third modified example, accurate pressure display can be performed, and the formability of the airtight member 225E is significantly improved. Thereby, the airtight member 225E can be manufactured at low cost.

[Sixth Modification]
A modification (sixth modification) of the air supply device used in place of the air supply device 210 in the overtube 201 of the third embodiment will be described.
As shown in FIG. 17, an air supply device 210F of this modification can be used in place of the air supply device 210 of the overtube 201. As shown in FIG.
As shown in FIG. 45, the air supply device 210F has a pressure indicator 219F instead of the pressure indicator 219 of the third modified example.
A pressure indicator 219F is the same as the pressure indicator 219 except that it has an airtight member 225F (sealing member, pressing member) and a reinforcing member 227F shown in FIG. 65 instead of the airtight member 225 of the third modified example. is.
FIG. 65 is a schematic cross-sectional view showing an example of an airtight member used in a modified example (sixth modified example) of the air supply device used in the endoscope overtube according to the third embodiment of the present invention. 66 is a cross-sectional view taken along line F66-F66 in FIG. 65. FIG.
In the following, differences from the third embodiment and the third modified example will be mainly described.

As shown in FIG. 65, the airtight member 225F is similar to the airtight member 225 except that it has a bellows tube portion 226 instead of the bellows tube portion 225d.
The bellows tube portion 226 is formed of an elastomer film having the same thickness tn as the thin portion 225t of the bellows tube portion 225d. The bellows tube portion 226 is bent in an inverted V shape at the mountain fold portion on the outer periphery. Therefore, the thick portion 225n is not formed on the outer peripheral portion of the bellows tube portion 226. As shown in FIG.

The reinforcing member 227F reinforces the mountain fold f on the outer periphery of the bellows tube portion 226, which has low rigidity in the radial direction, from the inner surface side. The reinforcing member 227</b>F is a linear body having a triangular cross section that is attached inside the mountain fold f of the bellows tube portion 226 .
As shown in FIG. 66 , the shape of the reinforcing member 227</b>F viewed from the axial direction is curved in a semicircular shape along half the inner circumference of the bellows tube portion 226 .
The thickness tr of the reinforcement member 227F in the radial direction is not particularly limited as long as it can obtain the same degree of rigidity as the thick portion 225n. The thickness tr can be appropriately set according to the rigidity of the material of the reinforcing member 227F.
Two reinforcing members 227F are arranged inside each mountain fold f. A pair of reinforcing members 227F in one mountain fold f has, for example, one circumferential end 227a in contact with the other circumferential end 227b, and forms an annular shape as a whole.
As a material of the reinforcing member 227F, for example, metal, resin, or the like may be used.

Since the airtight member 225F has a pair of reinforcing members 227F arranged inside the mountain folds f of the bellows tube portion 226, the rigidity in the radial direction is improved according to the rigidity of the reinforcing members 227F.
The radial rigidity of the airtight member 225F is determined by the rigidity of the bellows tube portion 226 excluding the portion where the reinforcing member 227F is arranged. Therefore, the axial rigidity of the airtight member 225</b>F is equivalent to the axial rigidity of the airtight member 225 .

An overtube 201 having an air supply device 210F of this modified example is the same as the overtube 201 except that it has an air supply device 210F instead of the air supply device 210 of the overtube 201 according to the third embodiment. is. Therefore, according to this modified example, as in the third embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this modified example, the radial rigidity of the bellows tube portion 226 can be improved without providing the bellows tube portion 226 with a thick portion. Therefore, even if the width of the thick portion becomes too large when the required radial rigidity is provided, the rigidity can be improved by using a highly rigid material for the reinforcing member 227F. Thereby, the size of the airtight member 225F can be reduced.
Since the reinforcing member 227F has a semicircular shape, it can be easily inserted into the airtight member 225F. This facilitates assembly.

[Seventh Modification]
A modification (seventh modification) of the air supply device used in place of the air supply device 210 in the overtube 201 of the third embodiment will be described.
As shown in FIG. 17, an air supply device 210G of this modified example can be used in place of the air supply device 210 of the overtube 201. As shown in FIG.
As shown in FIG. 45, the air supply device 210G has a pressure indicator 219G instead of the pressure indicator 219 of the third modified example.
A pressure indicator 219G is the same as the pressure indicator 219 except that it has an airtight member 225F and a reinforcing member 227G shown in FIG. 65 instead of the airtight member 225 of the third modified example. The airtight member 225F is the same member as in the sixth modification.
Hereinafter, the points different from the third embodiment, the third modified example, and the sixth modified example will be mainly described.

The reinforcement member 227G reinforces the mountain fold f on the outer periphery of the bellows tube portion 226, which has low rigidity in the radial direction, from the inner surface side, like the reinforcement member 227F in the sixth modification.
The reinforcement member 227G has the same shape as the reinforcement member 227F except that the shape when viewed from the axial direction is different.
67 is a cross-sectional view taken along line F67-F67 in FIG. 65. FIG.
As shown in FIG. 67, the reinforcing member 227G has a C shape extending substantially all around the inside of the mountain fold f. Therefore, one reinforcing member 227G is arranged at each mountain fold f.
As shown in FIG. 67, in the example, the ends 227c and 227d of the reinforcing member 227G in the circumferential direction face each other with a gap in the circumferential direction. Therefore, when the ends 227 c and 227 d are deformed so as to contact each other, the diameter is reduced, so that they can be easily arranged inside the bellows tube portion 226 . The reinforcing member 227G inserted inside the mountain-folded portion f expands in diameter due to its elastic restoring force and comes into close contact with the inside of the mountain-folded portion f.

The reinforcing member 227G in this modified example can improve the radial rigidity of the bellows tube portion 226 in the same manner as the pair of reinforcing members 227F in the sixth modified example.
While the pair of reinforcing members 227F reinforces each of the mountain folds f, the reinforcing member 227G has one member for each of the mountain folds f and can perform similar reinforcement. As a result, the number of assembly man-hours is reduced as compared with the sixth modification.

An overtube 201 having an air supply device 210F of this modified example is the same as the overtube 201 except that it has an air supply device 210G instead of the air supply device 210 of the overtube 201 according to the third embodiment. is. Therefore, according to this modified example, as in the third embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, according to this modification, similarly to the sixth modification, the radial rigidity of the bellows tube portion 226 can be improved without providing the bellows tube portion 226 with a thick portion.

The above-described third embodiment and modifications may be implemented with various modifications.
In the third modified example, an example in which the display window forming member 221 is a film has been described. However, the display window forming member 221 is not limited to a film.
For example, the display window forming member 221 may be formed of a printed layer printed on the side surface portion 220b.
For example, if the display window 221a can be formed by forming the case 220 by two-color molding, the display window forming member 221 may be omitted.

In the third modified example, it has been described that the outer cylindrical portion 223a has a constant thickness, and that the distal end surface of the outer cylindrical portion 223a forms the distal edge portion 223c. However, the shape of the tip edge portion 223c is not limited to this. For example, as indicated by a chain double-dashed line in FIG. 57, an inclined surface 223n may be formed at the distal end portion of the outer cylindrical portion 223a, which is inclined from the inner peripheral side to the outer peripheral side from the proximal side toward the distal end. . That is, the tip edge portion 223c may be formed by a tapered tip at the tip of the outer cylinder portion 223a. In this case, the radial width of the tip edge portion 223c is narrowed, so that the tip edge portion 223c is formed in a linear shape close to the inner peripheral surface 220f of the side surface portion 220b. The inner peripheral surface 220f is located near the inner peripheral surface 220f in the radial direction.
Thereby, the operator can visually recognize the position of the tip edge portion 223c near the inner peripheral surface 220f closer to the first scale line 221b and the second scale line 221c. This further reduces reading errors by the operator.

[Fourth embodiment]
An endoscope overtube according to a fourth embodiment of the present invention will be described.
FIG. 68 is a schematic perspective view showing an example of the endoscope overtube according to the fourth embodiment of the present invention. 69 is a cross-sectional view along line F69-F69 in FIG. 68. FIG.
An overtube 301 shown in FIG. 68 is an example of an endoscope overtube according to this embodiment.
The overtube 301 has an air supply device 310 instead of the air supply device 10 of the overtube 1 according to the first embodiment.
The air supply device 310 has a pressure indicator 319 instead of the pressure indicator 219 of the air supply device 210C in the third modified example.
In the following, differences from the first embodiment and the third modification will be mainly described.

As shown in FIG. 69, pressure indicator 319 has collar 323 (moving member) instead of collar 223 of pressure indicator 219 . The collar 323 has a locking plate 323b (elastic member supporting portion) instead of the locking plate 223b of the collar 223 .
69 shows a cross section passing through the center of the display window 221a in the circumferential direction and the central axis O ₂₂₀ of the case 220, as in FIG.
FIG. 70 shows a section similar to that of FIG. 69 with the main members extracted.

As shown in FIG. 70, the locking plate 323b is a wedge-shaped plate member whose thickness along one diameter gradually decreases from a maximum value to a minimum value.
A plane 323c forming the surface of the locking plate 323b on the base end side (left side in the drawing) in the axial direction is perpendicular to the central axis Oc of the locking plate 323b.
An inclined surface 323d forming the surface of the locking plate 323b on the tip side (right side in the drawing) in the axial direction rotates clockwise in the drawing by an angle α with respect to a plane perpendicular to the central axis Oc like the plane 323c. .
The proximal end of the coil spring 224 is locked to the inclined surface 323d, like the locking surface 223d of the collar 223. As shown in FIG.
The magnitude of the angle α is such that a biasing force that tilts the collar 323 in a certain direction acts on the collar 323 from the coil spring 224 in the range of the gap between the inner peripheral surface 220f and the outer peripheral surface of the outer cylindrical portion 223a of the collar 323. It is not particularly limited as long as it is small.

As shown in FIG. 69, the collar 323 is arranged so that the maximum thickness of the locking plate 323b is located radially toward the display window 221a.
69 and 70, the side closer to the display window 221a in the radial direction will be referred to as the upper side, and the side away from the display window 221a will be referred to as the lower side.
According to this modification, when the central axis Oc of the collar 323 is arranged coaxially with the central axis O _220, the distance between the surface of the base end side of the flange portion 225e on the upper side in the radial direction and the inclined surface 323d is the lower side. is shorter than the distance between the base end side surface of the flange portion 225e and the inclined surface 323d. As a result, the pressing force of the coil spring 224 is greater on the upper side than on the lower side.
As a result, as shown in FIG. 70, the collar 323 rotates counterclockwise as shown. In particular, if the gap between the outer cylindrical portion 223a and the inner peripheral surface 220f of the case 220 is large enough to allow the rotation of the angle α, the collar 323 rotates counterclockwise in the figure by the angle α. If the clearance is too narrow to rotate by the angle α, the collar 323 rotates by an angle smaller than α at which the outer peripheral portion of the outer cylindrical portion 223a contacts the inner peripheral surface 220f.
An example in which the collar 323 can be rotated by an angle α will be described below.
The distance between the base end side surface of the flange portion 225e to which the coil spring 224 engages and the inclined surface 323d is kept constant corresponding to the total length of the coil spring 224 when it expands and contracts.

As a result, the tip of the outer cylindrical portion 223a is close to the outer peripheral surface 220e on the upper side and separated from the outer peripheral surface 220e on the lower side. Similarly, the proximal end of the outer cylindrical portion 223a is separated from the outer peripheral surface 220e on the upper side and approaches the outer peripheral surface 220e on the lower side.
Collar 323 engages with sealing member 225 in the same manner as collar 223 in the third modification. As a result, the collar 323 is restricted from rotating around the central axis O ₂₂₀ . As a result, the tilt of the collar 323 is similarly maintained during axial movement.

In this embodiment, inside the case 220 of the pressure indicator 319, when the collar 323 moves along the central axis O220, the third third Pressure can be displayed in the same manner as the pressure indicator 219 of the modified example.
The tilting of collar 323 brings leading edge 223c closer to viewing window 221a. The reading error when the operator's viewing direction is tilted in the operator's lateral direction is reduced in the radial direction compared to the case where the leading edge portion 223c is located farther from the display window 221a. This allows the operator to read the pressure more accurately.
The inclined state of the collar 323 is formed by the elastic force of the coil spring 224 contacting the collar 323 and pressing the collar 323 toward the base end side. The tilt angle and tilt direction are kept constant.
The rotation of the collar 323 around the central axis Oc is restrained by the torsional rigidity of the airtight member 225 and the frictional force at the proximal end of the coil spring 224 .

The overtube 301 according to this embodiment is the same as the overtube 101 except that it has an air supply device 310 instead of the air supply device 10 of the overtube 101 according to the first embodiment. Therefore, according to this modified example, as in the first embodiment, it is possible to provide an endoscope overtube that reduces the burden on a patient and allows smooth operation of the endoscope.
In particular, according to this embodiment, the air supply device 310 has the pressure indicator 319 instead of the pressure indicator 219 of the third modified example, so reading errors in the pressure display due to changes in the viewing direction can be reduced.

In the pressure indicator 319 of the air supply device 310, the case 220 is an example of a housing provided with a display window 221a through which the inside can be seen at least partially.
In the pressure indicator 319, the collar 323 is an example of a moving member that moves within the housing according to the pressure inside the housing and whose movement position can be observed through the display window.
In the pressure indicator 319, the first scale line 221b and the second scale line 221c are formed around the display window or the display window, and are examples of reference scales indicating the pressure according to the position of the moving member.
A side portion 220b of the case 220 is an example of a moving pipe inside which a moving member moves.
The outer tube portion 223a of the collar 323 is an example of a tubular portion that moves along the central axis of the transfer conduit. Leading edge 223c is an example of the end of the tubular portion closer to the viewing window.
In the pressure indicator 319, the tubular portion moves in a tilted attitude in a certain direction with respect to the central axis of the moving conduit, and the display window is positioned at the end of the tubular portion that is closer to the display window due to the inclination of the tubular portion. is formed in a position where you can see the

The coil spring 224 in the pressure indicator 319 is an example of an elastic member that urges the moving member against the pressure acting on the moving member and regulates the moving position of the moving member according to the pressure.
The airtight member 225 and the fixed frame 222 in the pressure indicator 319 are an example of a pressing member that is arranged to face the moving member in the moving direction of the moving member and presses the end of the elastic member opposite to the moving member.
A locking plate 323b having an inclined surface 323d in the collar 323 is included in the moving member, and is an inclined surface inclined in a certain direction with respect to the central axis when the tubular portion is arranged coaxially with the central axis. The above is an example of the elastic member supporting portion that supports the elastic member.

The fourth embodiment described above may be implemented with the following modifications.
323 d of inclined surfaces in this modification were demonstrated as being formed in the whole locking plate 323b. However, the inclined surface 323d may be formed in a range that contacts the proximal end of the coil spring 224 . The inclined surface 323d may be provided in an annular shape when viewed from the axial direction in a range that contacts the coil spring 224, for example, between the pressing claw 223g and the outer cylindrical portion 223a. In this case, the portion of the locking plate 323b with which the bottom plate portion 225c of the airtight member 225 abuts is formed by a plane parallel to the plane 323c.

[Eighth modification]
A modification (eighth modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, a pressure indicator 319A of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
As shown in FIG. 69, the pressure indicator 319A has a collar 323A (moving member) instead of the collar 323. As shown in FIG.
In the following, the points different from the fourth embodiment will be mainly described.

FIG. 71 is a schematic cross-sectional view showing a main part of a modified example (eighth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention. FIG. 72 is a right side view of the collar in the eighth modification.
As shown in FIG. 71, the collar 323A has a locking plate 223b in the third modified example and a plurality of projecting portions 323f (elastic member supporting portions) instead of the locking plate 323b.
The locking plate 223b is orthogonal to the central axis Oc. A tip surface 323e on the tip side of the locking plate 223b in the axial direction along the central axis Oc is also orthogonal to the central axis Oc.

The distal end surfaces of the plurality of protrusions 323f in the axial direction along the central axis Oc are on the same plane rotated clockwise in the figure by an angle α with respect to the distal end surface 323e of the locking plate 223b on the distal side of the distal end surface 323e. located above.
The proximal ends of the coil springs 224 are locked to the plurality of projections 323f, like the inclined surfaces 323d in the fourth embodiment.
The arrangement position and the number of the plurality of protrusions 323f in the circumferential direction are not particularly limited as long as the proximal ends of the coil springs 224 can be arranged on the same plane.
For example, as shown in FIG. 72, the plurality of protrusions 323f may be composed of a first protrusion 323f1, a second protrusion 323f2, and a third protrusion 323f3.

The first projecting portion 323f1 and the third projecting portion 323f3 face each other across the central axis Oc in the radial direction extending vertically in the figure. Among the plurality of protrusions 323f, the first protrusion 323f1 has the largest protrusion amount from the tip surface 323e. Similarly, the amount of protrusion from the tip surface 323e of the third protrusion 323f3 is the smallest.
The second protrusions 323f2 are provided one each in the circumferential direction between the first protrusions 323f1 and the third protrusions 323f3. The amount of protrusion of each second protrusion 323f2 from the tip surface 323e is equal to the average of the protrusion amounts of the first protrusion 323f1 and the third protrusion 323f3.
The outer shape of each protrusion 323f when viewed from the axial direction is not particularly limited. For example, the outer shape of each protrusion 323f may be rectangular, polygonal, circular, or the like. In the example shown in FIG. 72, each protrusion 323f has a rectangular outer shape.
The shape of the tip of each projection 323f is not particularly limited as long as it can stably abut on the coil spring 224 . For example, it may be a plane that forms part of the inclined surface 323d, or a convex curved surface that contacts the same plane as the inclined surface 323d at at least one point.

This modification has a plurality of protrusions 323f instead of the inclined surface 323d. Since the distal end faces of the plurality of projections 323f are positioned on the same plane with the same inclination as a whole, when the proximal ends of the coil springs 224 come into contact with each of them, the collars 323A and the side faces 220b are aligned in the same manner as the collars 323. Tilt in a certain direction inside.
As a result, like the collar 323, the tip edge portion 223c is close to the display window 221a, so that the operator can read the pressure accurately.

The overtube 301 having the pressure indicator 319A of this modification has the same function as the overtube 301 according to the fourth embodiment.
In particular, in this modified example, the inclination of the collar 323A is defined by a plurality of protrusions 323f provided in a narrower range than in the fourth embodiment. For this reason, compared with the case of forming a wider inclined surface 323d, it is easier to obtain the accuracy of the inclination angle.

In this modified example, the proximal end of the coil spring 224 has been described as being in contact only with the plurality of projecting portions 323f. However, if the proximal end of the coil spring 224 can be aligned on the same plane, a portion of the coil spring 224 may abut on the distal end surface 323e. For example, the third projecting portion 323f3 may be removed, and the lower side of the proximal end of the coil spring 224 may be brought into contact with the distal end surface 323e.

A plurality of projecting portions 323f in the collar 323A are included in the moving member, and when the tubular portion is arranged coaxially with the central axis, it is elastic on an inclined surface inclined in a certain direction with respect to the central axis. It is an example of an elastic member supporting portion that supports a member.

[Ninth Modification]
A modification (ninth modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, the pressure indicator 319B of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
In the following, the points different from the fourth embodiment will be mainly described.

FIG. 73 is a schematic cross-sectional view showing main parts of a modification (ninth modification) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention.
As shown in FIG. 73, the pressure indicator 319B has an airtight member 325B (sealing member, pressing member) and a collar 323B (moving member) instead of the airtight member 225 and collar 323. As shown in FIG.

As shown in FIG. 73, an airtight member 325B has a bottom plate portion 325c instead of the bottom plate portion 225c of the airtight member 225 in the third modified example.
The bottom plate portion 325c is a wedge-shaped plate member whose thickness along one diameter gradually decreases from the maximum value to the minimum value.
A plane 325k that forms the surface of the bottom plate portion 325c on the tip side (right side in the drawing) in the axial direction is orthogonal to the central axis O ₂₂₀ , like the surface of the bottom plate portion 225c of the airtight member 225 on the tip side.
An inclined surface 325j forming the surface of the bottom plate portion 325c on the base end side (left side in the drawing) in the axial direction rotates counterclockwise in the drawing by an angle α with respect to the plane 325k.
The boss portion 225a in this modified example protrudes from the inclined surface 325j in the normal direction of the inclined surface 325j.
In this modification, instead of the engagement projections 225i of the third modification, engagement projections 325i protrude. However, the thickness of each engaging projection 325i varies according to the change in the thickness of the bottom plate portion 325c. That is, the base end surface of each engaging protrusion 325i extends radially along the inclined surface 325j, and the distal end surface extends radially along the flat surface 325k.
The airtight member 325B is arranged such that the position of the portion of the bottom plate portion 325c where the thickness is the maximum is positioned toward the display window 221a in the radial direction.

The collar 323B is the same as the collar 223 in the third modification except that it has a pressing claw 323g instead of the pressing claw 223g.
The pressing claw 323g is the same as the pressing claw 223g except that the amount of protrusion toward the tip side differs according to the thickness of the mating engagement projection 325i.

According to this modification, the inclined surface 325j of the bottom plate portion 325c of the airtight member 325B engages with the engaging surface 223d of the collar 223. As shown in FIG. This causes the collar 223 to rotate in the same manner as the collar 323 of the fourth embodiment. The central axis Oc rotates counterclockwise in the figure with respect to the central axis O ₂₂₀ by each angle α.
Accordingly, as with the collar 323, the tip edge portion 223c of the collar 223 in this modified example comes close to the display window 221a, so that the operator can read the pressure accurately.

The overtube 301 having the pressure indicator 319B of this modification has the same function as the overtube 301 according to the fourth embodiment.
This modification is an example in which the collar 223 in this modification is rotated by providing an inclined surface 325j on the base end side of the airtight member 325B.

The above-described ninth modification may be implemented with the following modification added.
The inclined surface 325j in this modified example may be formed entirely in the circumferential direction, or may be formed apart in the circumferential direction. When formed over the entire circumferential direction, in the radial direction, it may be formed in an annular shape when viewed from the axial direction within a range in contact with the coil spring 224 .
74 is a left side view of an airtight member in a ninth modification. FIG.
The example shown in FIG. 74 is an example in which the inclined surfaces 325j are respectively formed at the base ends in the axial direction of the plurality of protrusions 325p. The plurality of protrusions 325p protrude toward the proximal end from a plane 325n parallel to the plane 325k.
For example, the plurality of projections 325p may be composed of a first projection 325p1, a second projection 325p2, and a third projection 325p3, like the plurality of projections 323f in the eighth modified example.
The first protrusion 325p1, the second protrusion 325p2, and the third protrusion 325p3 project from the flat surface 325n toward the base end, and the slope surface 325j is formed on the surface of the base end. may be formed in the same position and shape as the first protrusion 323f1, the second protrusion 323f2, and the third protrusion 323f3 in .
Furthermore, the shape of the tip of each protrusion 325p is not particularly limited as long as it can stably contact the coil spring 224, like the protrusion 323f in the eighth modified example.

[Tenth Modification]
A modification (tenth modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, a pressure indicator 319C of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
In the following, the points different from the fourth embodiment will be mainly described.

FIG. 75 is a schematic cross-sectional view showing a main part of a modified example (tenth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention.
As shown in FIG. 75, the pressure indicator 319C has a fixed frame 322C (holding member) and a collar 223 instead of the fixed frame 222 and collar 323. As shown in FIG. The collar 223 is the same member as the collar 223 in the third modified example.

As shown in FIG. 75, a fixed frame 322C has a bottom surface portion 322a instead of the bottom surface portion 222a of the fixed frame 222 in the third modified example.
The bottom portion 322a is a wedge-shaped plate member whose thickness along one diameter gradually decreases from the maximum value to the minimum value.
A plane 322 h that forms the surface of the bottom surface portion 322 a on the tip side (right side in the drawing) in the axial direction is orthogonal to the central axis O ₂₂₀ .
An inclined surface 322i forming the surface of the bottom surface portion 322a on the base end side (left side in the drawing) in the axial direction rotates counterclockwise in the drawing by an angle α with respect to the flat surface 322h.
The tip side surface of the flange portion 225e contacts the inclined surface 322i.
The fixed frame 322C is fixed to the case 220 so that the maximum thickness of the bottom surface portion 322a is positioned toward the display window 221a in the radial direction.

According to this modification, the flange portion 225e of the airtight member 225 is engaged with the inclined surface 322i of the bottom surface portion 322a of the fixed frame 322C. As a result, the upper tip of the coil spring 224 that engages with the proximal surface of the flange portion 225e is pushed out more to the proximal side than the lower tip. Since the locking surface 223d of the collar 223 in this modified example is pressed more strongly on the upper side than on the lower side by the proximal end of the coil spring 224, the collar 223 is similar to the collar 323 of the fourth embodiment. Rotate. The center axis Oc rotates counterclockwise in the figure by an angle α with respect to the center axis O ₂₂₀ .
Accordingly, as with the collar 323, the tip edge portion 223c of the collar 223 in this modified example comes close to the display window 221a, so that the operator can read the pressure accurately.

The overtube 301 having the pressure indicator 319C of this modification has the same function as the overtube 301 according to the fourth embodiment.
This modification is an example in which the collar 223 in this modification is rotated by providing an inclined surface 322i on the base end side of the fixed frame 322C.

The tenth modified example described above may be implemented with the following modifications added.
The inclined surface 322i in this modified example may be formed entirely in the circumferential direction, or may be formed apart in the circumferential direction. When formed over the entire circumferential direction, in the radial direction, it may be formed in an annular shape when viewed from the axial direction in a range facing the coil spring 224 with the flange portion 225e interposed therebetween.
FIG. 76 is a left side view of a fixed frame in the tenth modification.
The example shown in FIG. 76 is an example in which inclined surfaces 322i are formed at proximal ends in the axial direction of a plurality of protrusions 322m (elastic member supporting portions). The plurality of protrusions 322m protrude toward the proximal end from a plane 322k parallel to the plane 322h.
For example, the plurality of projections 322m may be composed of a first projection 322m1, a second projection 322m2, and a third projection 322m3, like the plurality of projections 323f in the eighth modified example.
Except that the first protrusion 322m1, the second protrusion 322m2, and the third protrusion 322m3 protrude from the flat surface 322k toward the base end side and the base end surface is formed by the inclined surface 322i, the first protrusion 322m1, the second protrusion 322m2, and the third protrusion 322m3 are the same as the eighth modified example. It may be formed in the same position and shape as the first protrusion 323f1, the second protrusion 323f2, and the third protrusion 323f3.
Furthermore, the shape of the tip of each protrusion 322m is not particularly limited as long as it can stably contact the coil spring 224, like the protrusion 323f in the eighth modified example.

The airtight member 225 and the fixed frame 322C in the pressure indicator 319C are an example of a pressing member that is arranged to face the moving member in the moving direction of the moving member and presses the end of the elastic member opposite to the moving member.
A bottom surface portion 322a having an inclined surface 322i or a plurality of protrusions 323f in the fixed frame 322C are included in the pressing member, and when the tubular portion is arranged coaxially with the central axis, it is fixed to the central axis. It is an example of an elastic member supporting portion that supports an elastic member on an inclined surface inclined in a direction.

[11th Modification]
A modification (eleventh modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, a pressure indicator 319D of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
In the following, the points different from the fourth embodiment will be mainly described.

FIG. 77 is a schematic cross-sectional view showing a main part of a modified example (eleventh modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention.
As shown in FIG. 77, the pressure indicator 319D has an airtight member 325D (sealing member, pressing member) and a collar 223 instead of the airtight member 225 and collar 323. As shown in FIG. The collar 223 is the same member as the collar 223 in the third modified example.

As shown in FIG. 77, the airtight member 325D has a flange portion 325e (elastic member supporting portion) instead of the flange portion 225e of the airtight member 225 in the third modified example.
The flange portion 325e is an annular plate member whose thickness along one diameter gradually decreases from the maximum value to the minimum value at least at the portion where the tip of the coil spring 224 abuts. .
A plane 325 s that forms the surface of the flange portion 325 e on the distal end side (right side in the drawing) in the axial direction is perpendicular to the central axis O ₂₂₀ .
The inclined surface 325t forming the surface of the flange portion 325e on the proximal side (left side in the drawing) in the axial direction rotates counterclockwise in the drawing by an angle α with respect to the flat surface 325s.
The plane 325 s abuts on the base end side surface of the bottom portion 222 a of the fixed frame 222 .
The tip of the coil spring 224 contacts the inclined surface 325t.
The airtight member 325D is fixed by the case 220 and the fixing frame 222 so that the maximum thickness of the flange portion 325e is positioned radially toward the display window 221a.

According to this modification, when the flat surface 325s of the flange portion 325e of the airtight member 325D is engaged with the bottom surface portion 222a of the fixed frame 222, the inclined surface 325t is inclined at an angle α with respect to the plane perpendicular to the central axis O ₂₂₀ . It inclines in the direction of counterclockwise rotation in the drawing.
As a result, the upper tip of the coil spring 224 that engages with the inclined surface 325t of the flange portion 325e is pushed out more toward the base end than the lower tip. Since the locking surface 223d of the collar 223 in this modified example is pressed more strongly on the upper side than on the lower side by the proximal end of the coil spring 224, the collar 223 is similar to the collar 323 of the fourth embodiment. Rotate. The center axis Oc rotates counterclockwise in the figure with respect to the center axis O ₂₂₀ by an angle α.
Accordingly, as with the collar 323, the tip edge portion 223c of the collar 223 in this modified example comes close to the display window 221a, so that the operator can read the pressure accurately.

The overtube 301 having the pressure indicator 319D of this modification has the same function as the overtube 301 according to the fourth embodiment.
This modification is an example in which the collar 223 in this modification is rotated by providing an inclined surface 325t on the base end side of the flange portion 325e of the airtight member 325D.

The eleventh modified example described above may be implemented with the following modifications added.
325 t of inclined surfaces in this modification may be formed all over the circumferential direction, and may be formed apart in the circumferential direction. When formed over the entire circumference, in the radial direction, it may be provided in an annular shape when viewed from the axial direction in a range facing the coil spring 224 .
FIG. 78 is a left side view of an airtight member in an eleventh modification.
The example shown in FIG. 78 is an example in which the inclined surface 325t is formed at the proximal ends in the axial direction of the plurality of protrusions 325r (elastic member supporting portions). The plurality of projections 325r protrude toward the base end from a plane 325q parallel to the plane 325s.
For example, the plurality of projections 325r may be composed of a first projection 325r1, a second projection 325r2, and a third projection 325r3, like the plurality of projections 323f in the eighth modified example.
The first protrusion 325r1, the second protrusion 325r2, and the third protrusion 325r3 project from the flat surface 325q toward the proximal side, and the slope surface 325t is formed on the surface of the proximal end. may be formed in the same manner as the first protrusion 323f1, the second protrusion 323f2, and the third protrusion 323f3 in .
Further, the shape of the tip of each protrusion 325r is not particularly limited as long as it can stably contact the coil spring 224, like the protrusion 323f in the eighth modified example.

The airtight member 325D and the fixed frame 222 in the pressure indicator 319D are an example of a pressing member that is arranged to face the moving member in the moving direction of the moving member and presses the end of the elastic member opposite to the moving member.
A flange portion 325e having an inclined surface 325t or a plurality of protrusions 325r in the airtight member 325D is included in the pressing member, and when the tubular portion is arranged coaxially with the central axis, it is fixed to the central axis. It is an example of an elastic member supporting portion that supports an elastic member on an inclined surface inclined in a direction.

[Twelfth Modification]
A modification (twelfth modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, the pressure indicator 319E of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
In the following, the points different from the fourth embodiment will be mainly described.

FIG. 79 is a schematic cross-sectional view showing a main part of a modified example (twelfth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention.
As shown in FIG. 79, a pressure indicator 319E has a case 320E (housing) and a collar 323E (moving member) instead of the case 220 and collar 323 in the fourth embodiment.

The case 320E has a convex portion 320f that protrudes radially inward from an inner peripheral surface 220f of the side surface portion 220b. The cross-sectional shape of the convex portion 320f is the same in the axial direction.
The cross-sectional shape of the convex portion 320f is not particularly limited as long as it can restrict the circumferential rotation of the collar 323E by protruding from the inner peripheral surface 220f. In the example shown in FIG. 79, the convex portion 320f is a plane appearing as a chord of a circle along the inner peripheral surface 220f in a cross section perpendicular to the axial direction. As a result, the inner surface of the case 320E viewed from the axial direction is D-shaped.
The position of the convex portion 320f in the circumferential direction is not particularly limited. However, when the convex portion 320f is provided at a position crossing the display window 221a, a surface parallel to the surface of the convex portion 320f is formed at a portion corresponding to the inner side of the display window 221a, as indicated by the two-dot chain line. A recess 320e may be formed. In this case, since the thickness of the convex portion 320f inside the display window 221a is constant, the tip edge portion 223c can be visually recognized without distortion.

The collar 323E is similar to the collar 323 except that it has a recessed portion 323i that is recessed radially inward from the outer peripheral surface 323p of the outer cylinder portion 223a. The cross-sectional shape of the recess 323i is the same in the axial direction.
The cross-sectional shape of the recess 323i is recessed from the outer peripheral surface 323p, and is not particularly limited as long as it can restrict the circumferential rotation of the collar 323E when it slides close to the protrusion 320f. In the example shown in FIG. 79, the recess 323i is a plane that appears as a chord of a circle along the outer peripheral surface 323p in a cross section perpendicular to the axial direction. As a result, the outer surface of the collar 323E viewed from the axial direction is a D-shape that is slidably fitted in the inner surface of the case 320E in the axial direction.
However, a gap is formed between the inner surface of the case 320E and the outer surface of the collar 323E so that the collar 323E can be tilted in the same manner as the collar 323E.

According to this modification, when the collar 323E is inserted into the side surface portion 220b of the case 320E, the convex portion 320f and the concave portion 323i face each other closely. This restricts the rotation of the collar 323E in the circumferential direction.
For example, in the case of the fourth embodiment that does not have the convex portion 320f, the collar 323 is fixed to the airtight member 225 and is restricted from rotating in the circumferential direction by contacting the coil spring 224 . However, if the torsional rigidity of the airtight member 225 is low, or if the frictional force between the coil spring 224 and the locking plate 323b is reduced, the collar 323 may rotate in the circumferential direction. In this case, since the position of the tip edge portion 223c appearing in the display window 221a is not constant, there is a possibility that the display accuracy of the pressure is lowered.
In contrast, in this modified example, the rotation of the collar 323E is more reliably restricted by the projection 320f. According to this modification, the position of the tip edge portion 223c appearing in the display window 221a is constant, so the internal pressure of the case 220 can be displayed with high accuracy.

The overtube 301 having the pressure indicator 319E of this modification has the same function as the overtube 301 according to the fourth embodiment.
In this modification, the collar 323 rotates around the case 320E by fitting the D-shaped outer surface and the D-shaped inner surface respectively formed by the concave portion 323i of the collar 323E and the convex portion 320f of the case 320E. This is an example of stopping.

[Thirteenth Modification]
A modification (13th modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, the pressure indicator 319F of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
In the following, the points different from the fourth embodiment will be mainly described.

FIG. 80 is a schematic cross-sectional view showing a main part of a modified example (13th modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention.
As shown in FIG. 80, a pressure indicator 319F has a case 320F (housing) and a collar 323F (moving member) instead of the case 220 and collar 323 in the fourth embodiment.

Case 320F is similar to case 220 except that it has ridges 320g. The ridge 320g protrudes radially inward from the inner peripheral surface 220f of the side surface portion 220b and extends in the axial direction. The cross-sectional shape of the ridge 320g is the same in the axial direction.
The cross-sectional shape of the ridge 320g is not particularly limited as long as it can restrict the circumferential rotation of the outer cylindrical portion 223a. For example, the cross-sectional shape of the ridge 320g may be rectangular, triangular, trapezoidal, semicircular, or the like. In the example shown in FIG. 80, the ridge 320g has a rectangular shape protruding radially inward from the inner peripheral surface 220f.
The position of the protrusion 320f in the circumferential direction is not particularly limited as long as it does not cross the display window 221a.

Collar 323F is similar to collar 323 except that it has a groove 323j. The groove portion 323j is recessed radially inward from the outer peripheral surface 323p of the outer cylindrical portion 223a and extends in the axial direction.
The groove portion 323j is not particularly limited as long as it has a shape that fits the ridge 320g so as to be slidable in the axial direction. In the example shown in FIG. 80, the cross section of the groove 323j is also rectangular in correspondence with the rectangular projection 320g.
However, as in the twelfth modification, a gap is formed between the inner surface of the case 320F and the outer surface of the collar 323F so that the collar 323F can be tilted in the same manner as the collar 323F.

According to this modification, when the collar 323F is inserted into the side surface portion 220b of the case 320F, the projection 320g is axially movably fitted into the groove portion 323j. This restricts the rotation of the collar 323F in the circumferential direction. The collar 323F can move axially along the ridge 320g.

The overtube 301 having the pressure indicator 319F of this modification has the same function as the overtube 301 according to the fourth embodiment.
This modification is an example in which the collar 323F and the case 320F are prevented from turning by fitting grooves 323j and ridges 320g formed in the respective parts.
A similar fitting is performed by ridges similar to the ridges 320g except that they protrude radially outward from the outer peripheral surface 323p of the collar 323F, and that they are recessed radially outward from the inner peripheral surface 220f of the case 320F. and a groove similar to the groove 323j. In this case as well, the collar 323F and the case 320F can be prevented from rotating.

[14th Modification]
A modification (14th modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, the pressure indicator 319H of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
In the following, the points different from the fourth embodiment will be mainly described.

FIG. 81 is a schematic cross-sectional view showing a main part of a modified example (14th modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention.
As shown in FIG. 81, a pressure indicator 319H has a case 320H (housing) and a collar 323H (moving member) instead of the case 220 and collar 323 in the fourth embodiment.

Case 320H is similar to case 220 except that it has a groove 320h. The groove portion 320h is recessed radially outward from the inner peripheral surface 220f of the side surface portion 220b and extends in the axial direction. The cross-sectional shape of the groove portion 320h can have various cross-sectional shapes, like the groove portion 323j in the thirteenth modification.
The position of the groove 320h in the circumferential direction is not particularly limited as long as it does not cross the display window 221a.

Collar 323H is similar to collar 323 except that it has ridges 323k and protrusions 323m.
The protrusion 323k protrudes radially outward from the outer peripheral surface 323p of the outer cylindrical portion 223a and extends in the axial direction. The cross-sectional shape of the protrusion 323k is a shape that fits in the groove 320h and is relatively movable in the axial direction. As for the cross-sectional shape of the ridge 323k, various cross-sectional shapes are possible as long as the ridge 323k can be fitted into the groove 320h, similarly to the ridge 320g in the thirteenth modification.

The convex portion 323m protrudes radially outward from the outer peripheral surface 323p. The convex portion 323m is provided at a position that is distant from the ridge 323k in the circumferential direction and that is not visible from the display window 221a indicated by the two-dot chain line. The convex portion 323m may be provided at one location, but may be provided at a plurality of locations in the circumferential direction or the axial direction. In the example shown in FIG. 81, the convex portions 323m are provided at four positions in the circumferential direction.
As for the arrangement position of the convex portion 323m, a position that is likely to come into contact with the inner peripheral surface 220f may be selected in consideration of the inclination of the collar 323H.
The convex portion 323m is provided for the purpose of reducing sliding resistance with the inner peripheral surface 220f. Therefore, the shape, number, and formation position of the convex portion 323m are not particularly limited as long as the sliding resistance with the inner peripheral surface 220f can be reduced. More preferably, the convex portion 323m is formed by a convex curved surface that makes point contact with the inner peripheral surface 220f smoothly.
For example, the protrusion 323m may be a ridge extending in the axial direction or the circumferential direction, or may be a spot-shaped protrusion when viewed from the radial direction. A particularly preferable shape for the convex portion 323m is an axially extending ridge with a semicircular cross section or a hemispherical projection.

According to this modified example, when the collar 323H is inserted into the side surface portion 220b of the case 320H, the protrusion 323k fits into the groove portion 320h. This restricts the rotation of the collar 323H in the circumferential direction. The collar 323H can move axially along the ridge 323k as a track.
In this modification, since the convex portion 323m protrudes from the outer peripheral surface 323p, the sliding resistance of the collar 323H with respect to the inner peripheral surface 220f is reduced compared to the case where the convex portion 323m is not provided. In the pressure indicator 319H, even if the change in internal pressure of the case 320H is small, the collar 323H can smoothly follow the change in pressure. Thereby, the internal pressure of the case 320H can be displayed more accurately.

The overtube 301 having the pressure indicator 319H of this modification has the same function as the overtube 301 according to the fourth embodiment.
This modification is an example in which the collar 323H and the case 320H are prevented from rotating by fitting the ridges 323k and the grooves 320h respectively formed on the collar 323H and the case 320H.

The fourteenth modification described above may be implemented with the following modification added.
The protrusion height of the protrusion 323m may be changed according to the arrangement position. For example, the convex portion 323m may be formed with a height that allows it to be positioned equidistant from the inner peripheral surface 220f when the collar 323H is tilted by the angle α. In this case, in the state where the collar 323H is inclined, the contact of the convex portion 323m against the inner peripheral surface 220f becomes substantially uniform in the axial direction. This reduces variations in the tilted attitude of the collar 323H. Such a convex portion 323m has a function of keeping the inclination of the collar 323H substantially constant in addition to the function of reducing the sliding resistance.

[Fifteenth Modification]
A modification (a fifteenth modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, the pressure indicator 319J of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
FIG. 82 is a schematic cross-sectional view showing the main part of a modification (fifteenth modification) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention.
As shown in FIG. 82, a pressure indicator 319J has a case 320J (housing) and a collar 323F instead of the case 220 and collar 323 in the fourth embodiment. The collar 323F is the same member as the collar 323F in the thirteenth modification.
Differences from the fourth embodiment and the thirteenth modification will be mainly described below.

Case 320J is similar to case 220, except that it has protrusions 320i.
The convex portion 320i is the same as the convex portion 323m in the fourteenth modification, except that it protrudes radially inward from the inner peripheral surface 220f with a constant protrusion height. However, in order to prevent the protrusion 320i from being caught by the distal end and the proximal end when the collar 323F is moved, the protrusion 320i is more preferably an axially continuous ridge.
The apex of the protrusion 320i in the projecting direction is located on the same cylindrical surface coaxial with and smaller in diameter than the inner peripheral surface 220f.

According to this modification, when the collar 323F is inserted into the side surface 220b of the case 320J, the projection 320g is axially movably fitted into the groove 323j as in the thirteenth modification. As a result, the collar 323F is prevented from rotating, as in the thirteenth modification. The collar 323F can move axially along the ridge 320g.
Furthermore, in this modified example, since the convex portion 320i protrudes from the inner peripheral surface 220f, the sliding resistance of the collar 323F with respect to the case 320J is reduced as compared with the 13th modified example. Therefore, in the pressure indicator 319J, even if the change in the internal pressure of the case 320H is small, the collar 323F smoothly follows the change in pressure, and the internal pressure of the case 320J can be displayed more accurately.

The overtube 301 having the pressure indicator 319J of this modification has the same function as the overtube 301 according to the fourth embodiment.
This modification is an example in which the sliding resistance received by the collar 323F is reduced by providing the convex portion 320i on the inner peripheral surface 220f.

[16th Modification]
A modification (sixteenth modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, a pressure indicator 319K of this modified example can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
FIG. 83 is a schematic perspective partial cross-sectional view showing a main part of a modified example (sixteenth modified example) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention. FIG. 84 is a right side view of a collar used in a modified example (16th modified example) of the pressure indicator. 85 is a cross-sectional view taken along line F85-F85 in FIG. 84. FIG.

As shown in FIG. 83, the pressure indicator 319K has a collar 323K (moving member) and an airtight member 325K (sealing member, pressing member) instead of the collar 323 and airtight member 225. As shown in FIG.
In the following, the points different from the fourth embodiment will be mainly described.

As shown in FIG. 84, the collar 323K has a fitting claw 223f, a pressing claw 223g, a hole 223j, and a hole 223k removed from the locking plate 223b, and a step portion 323q (elastic member supporting portion) is added. Except for this, it is the same as the collar 223 in the third modification.
The stepped portion 323q protrudes axially from the locking surface 223d of the locking plate 323b toward the distal end side and extends along the inner peripheral surface of the outer cylindrical portion 223a.
The stepped portion 323q is formed with recesses 323r that are recessed to the same height as the locking surface 223d at four locations that equally divide the inner circumference of the outer cylindrical portion 223a in the circumferential direction.
The width of each recess 323r in the circumferential direction is such that it can be engaged with an engaging projection 325f of an airtight member 325K, which will be described later.
An inner peripheral surface 323s of each stepped portion 323q in the radial direction is a curved surface along a cylindrical surface having a size that allows a bottom plate portion 225c of an airtight member 325K, which will be described later, to be inserted along the outer peripheral surface of the bottom plate portion 225c.

As shown in FIG. 85, an inclined surface 323h is formed at the tip of each stepped portion 323q in the axial direction.
Each inclined surface 323h is located on the same plane having an inclination rotated clockwise by an angle α with respect to the locking surface 223d orthogonal to the central axis Oc.
On the upper side where the tip edge portion 223c is close to the display window 221a, the distance between the locking surface 223d and the inclined surface 323h is h1. On the radially opposite lower side, the distance between the locking surface 223d and the inclined surface 323h is h2, which is shorter than h1.

FIG. 86 is a perspective view of an airtight member used in a modification (sixteenth modification) of the pressure indicator. 87 is a cross-sectional view taken along line F87-F87 in FIG. 86. FIG. 88 is a cross-sectional view taken along line F88-F88 in FIG. 86. FIG.
As shown in FIG. 86, the airtight member 325K is similar to the airtight member 225 except that the fitting projection 225b is eliminated and the engagement projection 225i is replaced with the engagement projection 325f.
Like the engaging projections 225i, the engaging projections 325f extend radially outward from four locations that equally divide the outer circumference of the bottom plate portion 225c into quarters in the circumferential direction. Each engaging protrusion 325f extends close to the inner peripheral surface of the outer cylindrical portion 223a, as indicated by a two-dot chain line in FIG. Each engagement projection 325f is inserted into each recess 323r of the collar 323K. As a result, the engaging projection 325f is restricted from moving in the circumferential direction, so that the airtight member 325K is prevented from rotating in the circumferential direction.

The engaging projection 325f is composed of, for example, a first engaging projection 325f1, a second engaging projection 325f2, and a third engaging projection 325f3.
The first engagement protrusion 325f1 is inserted into the upper recess 323r in the drawing near the display window 221a (see the two-dot chain line) and the tip edge portion 223c in the radial direction.
The third engaging projection 325f3 is arranged on the lower side in the drawing opposite to the first engaging projection 325f1 in the radial direction.
A pair of second engaging projections 325f2 are provided at positions facing each other in a radial direction perpendicular to the opposing direction of the first engaging projection 325f1 and the third engaging projection 325f3.

As shown in FIG. 87, the proximal side (left side in the figure) surfaces of the first engaging projection 325f1 and the third engaging projection 325f3 extend along the proximal side first surface s1 of the bottom plate portion 225c. .
The first engaging projection 325f1 and the third engaging projection 325f3 protrude to the tip side (right side in the figure) from the second surface s2 on the tip side of the bottom plate portion 225c.
An inclined surface 325g located on the same plane and inclined at an angle α clockwise with respect to the first surface s1 is formed on the surfaces of the first engaging projection 325f1 and the third engaging projection 325f3 on the tip end side. there is
The maximum thickness t1 of the first engaging projection 325f1 is slightly thicker than the depth h1 of the upper recess 323r.
The minimum thickness t3 of the third engaging projection 325f3 is slightly thicker than the depth h2 of the lower recess 323r.

As shown in FIG. 88, the base end side (left side in the figure) surface of each second engaging projection 325f2 extends along the first surface s1.
A tip-side surface 325h that is a surface on the tip side (right side in the drawing) of each second engaging projection 325f2 may be an inclined surface similar to the inclined surface 325g, or a recess 323r into which each second engaging projection 325f2 is inserted. A plane parallel to the second surface s2 may be used as long as it is equivalent to the depth of . When the tip side surface 325h has the same inclination as the sloped surface 325g, the tip side surface 325h is positioned on the same plane as the sloped surfaces 325g of the first engaging projection 325f1 and the third engaging projection 325f3.

In this modification, the coil spring 224 is arranged between each stepped portion 323q and the flange portion 225e of the airtight member 325K. Therefore, as shown in FIG. 83, the proximal end of the coil spring 224 is located on the distal end side of each engaging protrusion 325f. A portion of each engaging protrusion 325f protruding from the recess 323r is pressed by the proximal end of the coil spring 224 from the distal end side. As a result, the engaging projection 325f is prevented from slipping out of the recess 323r in the axial direction.
Since each pushed engaging projection 325f is deformed in the thickness direction, the proximal end of the coil spring 224 abuts on the inclined surface 325g of each stepped portion 323q.

According to this modification, the inclined surface 325g with which the proximal end of the coil spring 224 abuts is inclined by the angle α. When the proximal end of the coil spring 224 abuts against each inclined surface 325g, the collar 323K is inclined by an angle α inside the side surface portion 220b, like the collar 323 in the fourth embodiment.
Accordingly, like the collar 323, the tip edge portion 223c of the collar 323K is close to the display window 221a, so that the operator can accurately read the pressure.

The overtube 301 having the pressure indicator 319K of this modification has the same function as the overtube 301 according to the fourth embodiment.
Especially in this modified example, by inserting each engagement projection 325f at the tip of the airtight member 325K into each recess 323r of the collar 323K, the airtight member 325K is prevented from turning and is axially prevented from coming off by the coil spring 224. .
This improves the assemblability of the pressure indicator 319K.
This modification is an example in which the projection formed on the tip side of the locking plate 223b is formed by a stepped portion 323q projecting from the locking surface 223d to the tip side for the purpose of tilting the collar 323K.

In the pressure indicator 319K, at the collar 323K, a step 323q with a sloping surface 323h is included in the moving member and is constant with respect to the central axis when the tubular portion is arranged coaxially with the central axis. It is an example of an elastic member supporting portion that supports an elastic member on an inclined surface inclined in a direction.

[17th Modification]
A modification (17th modification) of the pressure indicator used instead of the pressure indicator 319 in the overtube 301 of the fourth embodiment will be described.
As shown in FIG. 68, a pressure indicator 319L of this modification can be used in place of the pressure indicator 319 in the overtube 301. As shown in FIG.
FIG. 89 is a schematic perspective partial cross-sectional view showing a main part of a modification (seventeenth modification) of the pressure indicator used in the endoscope overtube according to the fourth embodiment of the present invention. 90 is an enlarged view of the F90 portion in FIG. 89. FIG.

As shown in FIG. 89, the pressure indicator 319L has a collar 323L (moving member) and an airtight member 325L (sealing member, pressing member) instead of the collar 323 and the airtight member 225. FIG.
Hereinafter, the points different from the fourth embodiment and the sixteenth modification will be mainly described.

The collar 323L is the same as the collar 223 in the third modified example except that it has a pressing claw 323t (elastic member supporting portion) instead of the pressing claw 223g.
All of the pressing claws 323t are provided radially outward from the pressing claws 223g. The position of each presser claw 323 t in the radial direction is the position where the distal end of the presser claw 323 t contacts the proximal end of the coil spring 224 .
Each pressing claw 323t is similar to the pressing claw 223g except that an inclined surface 323v having the same inclination as the inclined surface 323h in the sixteenth modification is formed at the tip in the axial direction. However, each presser claw 323t is different from the presser claw 223g in that instead of the engaging projection 325i, the engaging projection 325u of the airtight member 325L, which will be described later, is engaged in the axial direction.

The inclined surface 323v is formed on each pressing claw 323t and is located on the same plane inclined at an angle α with respect to the locking surface 223d.
As a result, the maximum height h3 from the locking surface 223d of the upper presser claw 323t1 closer to the display window 221a in the radial direction is higher than the minimum height h4 of the radially opposite presser claw 323t2.

As shown in FIG. 89, the airtight member 325L has an engaging projection 325u instead of the engaging projection 225i of the airtight member 225 in the fourth embodiment.
The engaging projection 325u is the same as the engaging projection 225i except that it has a length that allows it to be inserted between the pressing claw 323t and the locking plate 223b.
The length of the engagement projection 325u is such that it can enter the axial gap between the pressing claw 323t and the locking surface 223d.

As shown in FIG. 90, in the assembled state of the pressure indicator 319L, the surface of the engagement protrusion 325u on the distal end side in the axial direction is engaged with the proximal end surface of the pressing claw 323t. As a result, the engaging projection 325u is sandwiched between the locking surface 223d and the pressing claw 323t and engages with them in the axial direction. Although not shown in FIG. 90, the fitting protrusion 225b of the airtight member 325L axially engages with the fitting claw 223f (not shown) of the collar 323L, like the collar 223 in the third modification.
A proximal end of the coil spring 224 is in contact with the inclined surface 323v. Since the inclined surface 323v is the same inclined surface as the inclined surface 323h in the sixteenth modification, the collar 323L is inclined by the angle α within the case 220 in the same manner as the collar 323K in the sixteenth modification.

According to this modification, the tip of the presser claw 323t with which the proximal end of the coil spring 224 abuts is inclined by the angle α. When the proximal end of the coil spring 224 abuts on each presser claw 323t, the collar 323L is inclined at an angle α inside the side surface portion 220b, like the collar 323 in the fourth embodiment.
As a result, like the collar 323, the tip edge portion 223c of the collar 323L is close to the display window 221a, so that the operator can accurately read the pressure.

The overtube 301 having the pressure indicator 319L of this modification has the same function as the overtube 301 according to the fourth embodiment.
This modification is an example in which a protrusion formed on the tip side of the locking plate 223b is formed by a pressing claw 323t for the purpose of tilting the collar 323L.

In the pressure indicator 319L, in the collar 323L, a pressing pawl 323t having an inclined surface 323v is included in the moving member and is constant with respect to the central axis when the tubular portion is arranged coaxially with the central axis. It is an example of an elastic member supporting portion that supports an elastic member on an inclined surface inclined in a direction.

The above-described fourth embodiment and modifications may be implemented with various modifications.
For example, each configuration of the 12th to 15th modifications may be used in combination as appropriate. Each configuration of the 12th to 15th modifications is not limited to the case or collar in the fourth embodiment, and can be combined with the 8th to 11th modifications, the 16th modification, and the 17th modification. may

[Fifth embodiment]
An endoscope overtube according to a fifth embodiment of the present invention will be described.
An overtube 401 shown in FIG. 17 is an example of an endoscope overtube according to this embodiment.
The overtube 401 has an air supply device 410 instead of the air supply device 310 of the overtube 301 according to the third embodiment.
In the following, the points different from the third embodiment will be mainly described.

FIG. 91 is a schematic front view showing an air supply device in an endoscope overtube according to a fifth embodiment of the present invention; 92 is an enlarged view of the F92 portion in FIG. 91. FIG.
As shown in FIG. 91, an air supply device 410 in this embodiment has a body portion 412 instead of the body portion 212 in the third embodiment. The main body portion 412 has a housing portion 418 instead of the housing portion 218 of the main body portion 212 .
The housing part 418 is the same as the housing part 218 in the third embodiment except that a limiter 417 is provided near the connection pipe 212a.
A pump 211a in this embodiment has the same configuration as in the third embodiment.
The first connecting portion 211d is provided at the tip of the air pipe 211j. A first check valve 211b is provided inside the air supply pipe 211j. When the operator operates the pump 211a, the gas is sent out from the air pipe 211j.
The first connection portion 211d is an example of a first connector that detachably connects the air supply tube 211j to the connection tube 212a.
The second connection portion 211e is provided at the tip of the intake pipe 211k. A second check valve 211c is provided inside the intake pipe 211k. When the operator operates the pump 211a, gas is sucked into the suction pipe 211k from the outside.
The second connection portion 211e is an example of a second connector that detachably connects the intake pipe 211k to the connection pipe 212a.
In the following, the points different from the third embodiment will be mainly described.

The limiter 417 is used to manually remove the first connection portion 211d or the second connection portion 211e of the manual air supply mechanism 211 from the connection tube 212a when the first connection portion 211d or the second connection portion 211e is unlocked. The position of the air supply mechanism 211 is regulated.
Hereinafter, the direction along the center axis _AC of the connection pipe 212a is referred to as the attachment/detachment direction. When the manual air supply mechanism 211 is a rubber ball pump, the central axis A 2 _C is coaxial with the central axis A _{2 P} of the manual air supply mechanism 211 .
As shown in FIG. 92, the limiter 417 is provided on the side portion 418a of the housing portion 418 to which the connecting pipe 212a is fixed.
The shape of the limiter 417 is not particularly limited as long as it can restrict the movement of the first connection portion 211d or the second connection portion 211e in the attachment/detachment direction when the first connection portion 211d or the second connection portion 211e is unlocked. Below, an example in which the outer shape of the first connection portion 211d or the second connection portion 211e is substantially cylindrical, and an end surface 211i that intersects the attachment/detachment direction is formed at the end opposite to the side portion 418a in the attachment/detachment direction. An example of the case will be described.
The limiter 417 has a side plate portion 417a (locking member), an operating portion 417c, and a locking projection 417b (locking member).

The side plate portion 417a is an elastic plate extending in the attachment/detachment direction from the outside of the side portion 418a. The side plate portions 417a face each other with the connection pipe 212a interposed therebetween. The facing direction of each side plate portion 417a is a direction perpendicular to the attaching/detaching direction.
The facing distance between the side plate portions 417a is equal to or greater than the outer diameter of the first connection portion 211d.
The lateral width of the side plate portion 417a is narrower than the outer diameter of the first connection portion 211d. As a result, a part of the side surface of the first connecting portion 211d sandwiched between the side plate portions 417a protrudes outward from the lateral direction of the side plate portion 417a. As a result, the operator can operate the first connecting portion 211d sandwiched between the side plate portions 417a to mount, lock, unlock, and move the first connecting portion 211d with respect to the connecting tube 212a.

The side plate portion 417a can be made of elastic resin or metal. The side plate portion 417a can be elastically deformed outward in the opposite direction from the state in which it extends in the attachment/detachment direction when an external force acts on the tip in the extension direction.

The operation portion 417c is provided for the operator to perform an operation to open the tip of each side plate portion 417a in the extending direction outward.
The shape of the operation portion 417c is not particularly limited as long as the operator can apply an operation force in the direction to increase the distance between the side plate portions 417a. In the example shown in FIG. 92, the operation portion 417c is formed of a bent plate that bends outward in the facing direction from the tip of each side plate portion 417a in the extending direction and extends away from the side portion 418a in the attachment/detachment direction.
An operating lever 417d extending parallel to the central axis _AP is formed at the tip of each operating portion 417c in the extending direction.

The locking projection 417b protrudes inward in the opposite direction from the tip of each side plate portion 417a. The distance between the tips of the locking protrusions 417b in the protruding direction is smaller than the outer diameter of the first connecting portion 211d.
A locking surface 417e is formed on each locking projection 417b toward the connection pipe 212a in the attachment/detachment direction.
The locking surface _417e is a plane extending in a direction substantially perpendicular to the center axis AC.

Since the operation of the overtube 401 is the same as that of the overtube 301 except for the operation of the limiter 417, the operation of the overtube 401 will be described below, focusing on the operation of the limiter 417. FIG.
According to the limiter 417, for example, when the locked state of the first connecting portion 211d of the connecting pipe 212a is released, the first connecting portion 211d moves from the locked position with the connecting pipe 212a to the end face 211i as indicated by the two-dot chain line. can move along the attachment/detachment direction up to the locking position where the locking surface 417e is locked.
However, even if the manual air supply mechanism 211 is pulled out in the attaching/detaching direction, the first connecting portion 211d stops at the locking surface 417e. Therefore, the manual air supply mechanism 211 cannot be removed from the limiter 417 . Even if the operator releases the manual air supply mechanism 211 in the unlocked state, the manual air supply mechanism 211 will not fall.
However, when the operator opens the operating lever 417d outward, the side plate portions 417a are deformed so as to open outward. The operator can remove the first connecting portion 211d from the limiter 417 by opening the operating lever 417d until the distance between the locking protrusions 417b facing each other becomes larger than the outer diameter of the first connecting portion 211d.

On the other hand, when connecting the first connection portion 211d to the connection pipe 212a, the first connection portion 211d is inserted between the operation levers 417d, and the first connection portion 211d between the locking projections 417b is closed. just push it in. In this case, each side plate portion 417a receives an external force from each locking projection 417b that abuts on the side surface of the first connection portion 211d and bends outward. When the end surface 211i of the first connecting portion 211d passes between the locking projections 417b, the side plate portions 417a close inward.

The same applies when the second connection portion 211e is connected to the connection pipe 212a instead of the first connection portion 211d.

According to the present embodiment, since the air supply device 410 has the limiter 417, the first connection portion 211d can move within a certain distance from the connection tube 212a while the first connection portion 211d is unlocked. can be done. Furthermore, the manual air supply mechanism 211 does not come off from the limiter 417 unless the operator operates the operation part 417c.

With such a limiter 417 , the operator can exhaust the air inside the fixation balloon 3 without switching the manual air supply mechanism 211 from the first connection state to the second connection state.
That is, when the lock of the first connection portion 211d is released and the first connection portion 211d is retracted in the direction away from the connection pipe 212a, the pipe line in the first connection portion 211d and the pipe line in the connection pipe 212a are separated. A radial gap is created at the joint. As a result, the air in the pipeline downstream of the connecting pipe 212a leaks to the outside of the connecting pipe 212a.
The air leakage flow rate increases according to the distance separating the unlocked first connection portion 211d from the connection pipe 212a. Therefore, the operator can finely adjust the amount of exhausted air by finely adjusting the position of the first connecting portion 211d in the attachment/detachment direction.
For example, when too much air is supplied and the pressure of the fixation balloon 3 becomes too large, the operator can quickly reduce the pressure of the fixation balloon 3 by performing such an exhaust operation.
At this time, since the amount of movement of the first connection portion 211d is restricted by the locking projection 417b, it is possible to prevent a large amount of air from the fixation balloon 3 from being discharged.

By switching the manual air supply mechanism 211 to the second connection state, it is possible to inhale air from the fixation balloon 3, but in this case, since a large amount of air leaks while switching the connection state, the diameter of the fixation balloon 3 is reduced. After that, the air is supplied again, which is less efficient than the present embodiment.

The overtube 401 according to the present embodiment is the same as the overtube 301 according to the third embodiment except that it has a limiter 417, so it has the same function as the third embodiment. Therefore, as in the third embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
Especially in this embodiment, since a small amount of air can be rapidly discharged from the fixation balloon 3 during the air supply operation, the expansion/contraction operation of the fixation balloon 3 can be performed quickly and efficiently.

Pump 211a in gas delivery device 410 is an example of a manual pump that delivers gas. A body portion 412 in the air supply device 410 is an example of a body portion to which a manual pump is connected.
The connection pipe 212a in the body portion 412 is an example of a body side connector that protrudes from the body portion and detachably connects the manual pump in the first direction. Here, the first direction is the direction along the center axis _AC .
The first connecting portion 211d and the second connecting portion 211e are examples of pump-side connectors that advance and retreat in the first direction in the manual pump, are airtightly connected to the body-side connector when advancing, and leak the gas when retreating.
The limiter 417 is an example of a limiter that regulates the retracted position of the pump-side connector by engaging with the pump-side connector when retracting the pump-side connector and prevents the pump-side connector from coming off.
The side plate portion 417a and the locking protrusion 417b of the limiter 417 are examples of locking members that can move between a locking position where the pump-side connector can be locked and a removal position where the pump-side connector can be removed from the body-side connector. is.

[18th Modification]
A modification (eighteenth modification) of the air supply device used instead of the air supply device 410 in the overtube 401 according to the fifth embodiment will be described.
As shown in FIG. 17, an air supply device 410A of this modified example can be used in place of the air supply device 210 of the overtube 301. As shown in FIG.
FIG. 93 is a schematic cross-sectional view showing an example of a modified example (eighteenth modified example) of the limiter used in the endoscope overtube according to the fifth embodiment of the present invention. FIG. 94 is a schematic view of F94 in FIG. 93. FIG.

As shown in FIG. 93, an air supply device 410A of this modification has a limiter 417A instead of the limiter 417 in the fifth embodiment.
The following description will focus on the differences from the fifth embodiment.

The limiter 417A has a first side plate portion 417f (locking member), a second side plate portion 417g (locking member), and a fastener 417h (fixing member).
The first side plate portion 417f and the second side plate portion 417g are the same as the side plate portion 417a in the fifth embodiment, except that they extend longer than the side plate portion 417a. For this reason, the first side plate portion 417f and the second side plate portion 417g are each provided with locking projections 417b as in the fifth embodiment.
The fastener 417h fixes the facing distance between the first side plate portion 417f and the second side plate portion 417g facing each other so as to be able to expand.
The configuration of the fastener 417h is not particularly limited as long as the space between the first side plate portion 417f and the second side plate portion 417g can be expanded and fixed. In the example shown in FIG. 94, it extends from the side end of the tip portion of the first side plate portion 417f toward the side end of the second side plate portion 417g, and detachably engages with the second side plate portion 417g at the tip portion in the extending direction. It is an elastic claw that
An engaging protrusion 417i that detachably engages with the side end of the second side plate portion 417g protrudes from the tip of the fastener 417h.

In FIG. 94, the engaging protrusion 417i is a protrusion that engages from the outside of the second side plate portion 417g. However, the engagement protrusion 417i may be a protrusion in which a groove that engages the second side plate portion 417g is locked.
The fastener 417h is disengaged from the second side plate portion 417g by rotating clockwise around the proximal end connected to the first side plate portion 417f.
The first side plate portion 417f and the second side plate portion 417g may be parallel to each other as in the fifth embodiment, or may be open in such a manner that the distance between them increases as the distance from the side portion 418a increases.
When they are parallel to each other, the operator rotates the fastener 417h clockwise in the figure to release the engagement with the second side plate portion 417g, and moves the first side plate portion 417f and the second side plate portion 417g in the opposite direction. Manual air supply mechanism 211 can be removed by opening outward.

If the first side plate portion 417f and the second side plate portion 417g before engagement have a shape that opens in the opposite direction, the gap between the first side plate portion 417f and the second side plate portion 417g is narrowed when engaging. , are engaged by fasteners 417h. This fixes the gap between the first side plate portion 417f and the second side plate portion 417g.
When the operator operates the fastener 417h to release the engagement between the fastener 417h and the second side plate portion 417g, the first side plate portion 417f and the second side plate portion 417g return to the opened state due to the elastic force, so manual air supply is required. Removability of the mechanism 211 is possible.

According to the limiter 417A, when the fastener 417h is engaged, the movement range of the first connecting portion 211d is restricted by the locking projection 417b, as in the fifth embodiment.
When the operator disengages the fastener 417h, the manual air supply mechanism 211 can be removed from the limiter 417A as described above.

According to this modification, since the air supply device 410A has the limiter 417A, it has the same effect as the fifth embodiment.

The limiter 417A in the air supply device 410A is an example of a limiter that regulates the retracted position of the pump-side connector by engaging with the pump-side connector when retracting the pump-side connector and prevents the pump-side connector from coming off.
The first side plate portion 417f and the second side plate portion 417g of the limiter 417A, and the locking projections 417b provided on each of them, have a locking position where the pump side connector can be locked, and a pump side connector can be removed from the main body side connector. and a locking member movable to a removable position.
Fastener 417h in limiter 417A is an example of a securing member that can secure the locking member in one or both of the locked position and the removed position.

[Sixth embodiment]
An endoscope overtube according to a sixth embodiment of the present invention will be described.
An overtube 501 shown in FIG. 1 is an example of an endoscope overtube according to this embodiment.
The overtube 501 has an airtight valve unit 506 instead of the airtight valve unit 6 of the overtube 1 according to the first embodiment.
The following description will focus on the differences from the first embodiment.

FIG. 95 is a schematic cross-sectional view showing an example of an airtight valve unit used in the endoscope overtube according to the sixth embodiment of the present invention.
As shown in FIG. 95, the airtight valve unit 506 in this embodiment is particularly suitable for inserting the endoscope 30 whose thickness changes in the longitudinal direction.
Like the airtight valve unit 6 in the first embodiment, the airtight valve unit 506 provides good airtightness even with a non-circular cross section like the endoscope 11 . However, in the following description, an example in which the outer shape of the endoscope 30 is a cylindrical surface will be described so that the features of the present embodiment can be more easily understood.

The thickness of the endoscope 30 may vary at any number of locations, and the thickness may vary continuously. However, for the sake of simplification, an example in which the endoscope 30 has a large diameter portion 30a and a small diameter portion 30b will be described below.

The large diameter portion 30a is cylindrical with an outer diameter D1.
The small diameter portion 30b is cylindrical with an outer diameter D2. However, D2 is smaller than D1.
The cause of the change in the outer diameter of the endoscope 30 is not particularly limited. For example, the fixation balloon 3 that is contracted outside the main tube 2 often has an outer diameter larger than the outer diameter of the main tube 2 even when contracted. In this case, the fixation balloon 3 in a diameter-reduced state forms the large-diameter portion 30a. For example, even when the endoscope 30 is withdrawn from the body while the diameter of the fixation balloon 3 is incompletely reduced for some reason, the fixation balloon 3 forms the large diameter portion 30a.
For example, an accessory such as the endoscope cap 13 in the first embodiment may be attached to the distal end portion of the endoscope 30 to form the large diameter portion 30a.

For example, when the endoscope 30 is inserted into the overtube 1 of the first embodiment, the inner diameter of the intermediate portion 22b is reduced by increasing the internal pressure of the space Sp, thereby reducing the outer diameter of the endoscope 30. The airtightness of the airtight valve unit 6 is maintained even if there is some change.
However, if the change in the outer diameter of the endoscope 30 becomes too large, the insertion resistance of the large-diameter portion 30a increases, and the endoscope 30 may not be smoothly inserted and removed.
It is conceivable that the operator or the like manually adjusts the amount of air in the space Sp to reduce the insertion resistance at the large-diameter portion 30a. However, from the viewpoint of reducing the burden on the patient and improving the efficiency of the operation, the endoscope 30 needs to be inserted and removed quickly. Since the operator or the like cannot accurately know the diameter-changing portion of the endoscope 30 inserted through the overtube 1, the operator or the like cannot accurately determine the timing at which the diameter-changing portion passes through the airtight valve unit 6. I can't comprehend. This makes it quite difficult for the operator or the like to appropriately adjust the opening of the airtight valve unit 6 .
There is a strong demand for an airtight valve with a simple structure that opens and closes in response to changes in the outer diameter of the endoscope 30 even when the outer diameter changes.

The airtight valve unit 506 includes a cylinder frame portion 521, an airtight balloon 522, and a connection port 521b (gas supply pipe) instead of the cylinder frame portion 21 (tubular portion), the airtight balloon 22, and the connection port 21b in the first embodiment. have.
Furthermore, the airtight valve unit 506 has a guide member 532 , a probe 534 , a spring 535 (biasing member), and a variable volume portion 531 .
In the following, the points different from the first embodiment will be mainly described.

The tubular frame portion 521 has an inner peripheral surface 21 a similar to that of the tubular frame portion 21 .
An airtight balloon 522 is fixed to the inner peripheral surface 21 a of the cylindrical frame portion 521 .
The airtight balloon 522 has an intermediate portion 522b instead of the intermediate portion 22b of the airtight balloon 22 in the first embodiment.
The intermediate portion 522b is a cylindrical surface that is in close contact with the inner peripheral surface 21a from the inside in a natural state in which no gas is supplied to the space Sp. When the gas is supplied to the space Sp, it expands radially inward according to the internal pressure of the space Sp. Similarly to the intermediate portion 22b in the first embodiment, the expanded intermediate portion 522b has an inner diameter that gradually decreases from the first joint portion 22a to the second joint portion 22c, becomes the minimum, and then expands. form a shape. The minimum diameter of the intermediate portion 522b changes according to the pressure of the space Sp.
If the amount of expansion of the intermediate portion 522b is adjusted according to the outer diameters of the large diameter portion 30a and the small diameter portion 30b, the sliding load between the large diameter portion 30a and the small diameter portion 30b does not change, and the respective outer peripheral portions can be hermetically covered.
Hereinafter, unless otherwise specified, the direction along the central axis of the inner peripheral surface 21a is referred to as the axial direction, and the direction perpendicular to the axial direction is referred to as the radial direction. As in the first embodiment, the leading end and the trailing end in the axial direction may be used based on the insertion direction of the overtube 501 .

A fixing portion 521d for fixing a guide member 532, which will be described later, is formed on the outer peripheral portion of the rear end portion of the cylindrical frame portion 521 in a range overlapping with the intermediate portion 522b when viewed in the radial direction. A guide hole 521e through which a probe 534, which will be described later, is inserted penetrates in the radial direction on the distal end side of the fixing portion 521d.

As shown in FIG. 1, the connection port 521b is connected to the operation tube main body 25, like the connection port 21b in the first embodiment.
As shown in FIG. 95, a check valve 521c is arranged inside the connection port 521b to prevent the backflow of the gas supplied to the space Sp.
The end of the connection port 521b near the space Sp is fixed to a guide member 532, which will be described later, penetrates a movable member 533, which will be described later, and opens inside the variable volume portion 531, which will be described later. The portion penetrating through the movable member 533 is hermetically sealed so that the movement load of the movable member 533 does not increase.
However, the connection port 521b may be fixed to the movable member 533 if the movement load of the movable member 533 does not increase.

The movable member 533 is arranged so as to be radially movable at a position facing the fixed portion 521d in the radial direction. In the example shown in FIG. 95 , the movable member 533 is radially movably supported by the guide member 532 and biased by the spring 535 in the radial direction toward the cylinder frame portion 521 .

The guide member 532 is fixed to the fixing portion 521d. The guide member 532 is formed with a guide portion 532a that moves the movable member 533 in parallel along the radial direction.
The shape of the guide member 532 is not particularly limited. For example, the guide member 532 may be a housing, a frame, a columnar body, a cylinder, or the like.
An appropriate shape is used for the shape of the guide portion 532 a according to the shape of the guide member 532 . For example, the guide portion 532a formed in the guide member 532 may be a radially extending hole, groove, ridge, or the like.
In the example schematically shown in FIG. 95, the guide member 532 is a frame or housing having a rectangular parallelepiped outer shape. The guide portion 532a is a through hole formed in the side surface of the guide member 532 and extending in the radial direction. In this case, the movable member 533 is translated in the radial direction by being inserted inside the guide portion 532a.

A probe 534 extending in the radial direction is fixed to a surface 533a of the movable member 533 that faces the outer peripheral portion of the cylindrical frame portion 521 in the radial direction.
The probe 534 is slidably inserted through the guide hole 521e. A sliding contact portion 534a (tip portion) formed on the tip side of the probe 534 can come into contact with the outer peripheral surface of the endoscope 30 moving axially within the inner peripheral surface 21a within the movable range of the movable member 533. have a length.
The sliding contact portion 534a has a curved surface that smoothly slides on the outer peripheral surface of the endoscope 30 . The sliding contact portion 534 a has a curvature that allows it to smoothly overcome a step on the outer diameter of the endoscope 30 .
The movable member 533 moves in the same direction as the probe 534 moving radially along the guide hole 521e.

The type and shape of the spring 535 are not particularly limited as long as they can urge the movable member 533 in the radial direction toward the tubular frame portion 521 .
For example, the type of the spring 535 is not particularly limited as long as it is an elastic member that generates an elastic restoring force according to the radial displacement of the movable member 533 . Examples of the spring 535 include a coil spring, a plate rubber, an elastic sheet, and the like. In the example shown in FIG. 95, spring 535 is a coil spring with probe 534 inserted therein. In this case, the spring 535 biases the movable member 533 with a tensile force.
When the endoscope 30 is inserted into the inner peripheral surface 21 a , the movable member 533 can move to a position where the sliding contact portion 534 a of the probe 534 contacts the side surface of the endoscope 30 .

The variable volume part 531 accommodates the gas supplied from the outside through the connection port 521b in the internal space Sv. The variable volume part 531 changes its volume according to the pressure of the gas.
The variable volume part 531 in this embodiment is a member that changes the volume of the space Sv without elastically expanding and contracting. For example, in the example shown in FIG. 95, the variable volume portion 531 is a corrugated tube in which a plurality of folds are arranged in a zigzag shape in the radial direction.
Both ends of the variable volume portion 531 in the radial direction are airtightly fixed to the bottom surface portion 532b of the guide member 532 fixed to the fixed portion 521d and to the surface 533a of the movable member 533, respectively.

An opening 521 f of the connection port 521 b fixed to the movable member 533 opens inside the variable volume portion 531 . The opening 521f allows communication between the space Sv and the interior of the connection port 521b.
The bottom surface portion 532b and the fixing portion 521d are provided with a pipe line 536 penetrating them in the radial direction.
The conduit 536 opens to the inside of the variable volume portion 531 and to the space Sp between the intermediate portion 522b and the inner peripheral surface 21a. Thereby, the conduit 536 allows the space Sp and the space Sv to communicate with each other.

In the airtight valve unit 506, when a certain volume of gas is supplied through the connection port 521b, the check valve 521c seals the gas in the spaces Sp and Sv.
Since the movable member 533 is supported movably in the radial direction, the volume of the space Sv changes according to the position of the movable member 533 . For example, when the movable member 533 moves in the radial direction toward the cylindrical frame portion 521, the variable volume portion 531 contracts in the radial direction, thereby reducing the volume of the space Sv. The gas that cannot enter the space Sv moves to the space Sp through the conduit 536 and expands the intermediate portion 522b.
At this time, the internal pressure in the spaces Sv and Sp increases, so the movable member 533 is urged in the direction opposite to the moving direction according to the internal pressure.

FIG. 96 is an operation explanatory view of the airtight valve unit used in the endoscope overtube according to the sixth embodiment of the present invention.
In this embodiment, as shown in FIGS. 95 and 96, gas is injected into the variable volume portion 531 so that the sliding contact portion 534a of the probe 534 is kept in contact with the side surface of the endoscope 30. .
In this state, by optimizing the volume of the gas introduced from the connection port 521b, the intermediate portion 522b of the airtight balloon 522 is brought into close contact with the outer peripheral portion of the endoscope 30 so that airtightness can be maintained.
For example, the airtight valve unit 506 satisfies the condition represented by the following formula (6a) using the pressures P ₁ , P _t , P _s and P _C shown in FIG.

Here, P ₁ is the internal pressure of the overtube 501 on the distal end side of the airtight balloon 522 . P _t is the pressure due to tension in the airtight balloon 522 . P _S is the internal pressure of the spaces Sp and Sv. P _C is the pressure corresponding to the biasing force of spring 535 .

Since intermediate portion 522b must be inflated to be airtight by airtight balloon 522, PS must be greater than the _sum of _P1 and Pt.
P1 is predetermined depending on the _type of surgery using the overtube 501, the type of lumen into which it is inserted, and the like.
_Pt is represented by the following formula (6b) based on the distortion of the airtight balloon 522 when inflated.

Here, E _S is the Young's modulus of the material of the airtight balloon 522 , L _BS is the perimeter length of the airtight balloon 522 when inflated, and L _S is the perimeter length of the airtight balloon 522 before inflation. However, the “peripheral length” of the airtight balloon 522 is the length of the intermediate portion 522b in the axial cross-section including the central axis of the airtight balloon 522 .

PS is determined based on _Boyle -Charles' law according to the volume of the gas injected into the variable volume part 531, and is represented by the following formula (6c).

Here, V is the volume of the gas injected into the variable volume part 531, _VS is the volume of the space Sp, _rb is the inner diameter of the variable volume part 531, h is the height of the variable volume part 531, and p is the atmospheric pressure. be. However, the inner diameter of the variable volume portion 531 is an equivalent diameter converted to a cylinder. For example, in the case of corrugated tubes, the average value of the maximum inner diameter and the minimum inner diameter is used.
h changes according to the position of the movable member 533 . However, in this embodiment, the position of the movable member 533 is uniquely determined corresponding to the outer diameter of the endoscope 30 with which the probe 534 abuts.
In this embodiment, the volume variable portion 531 does not elastically deform, so the volume of the space Sv is a function of h. Thus V _S is a function of V and h.
Once V _S is determined, the inner diameter of intermediate portion 522b is determined by numerical calculations or actual measurements of the expanded shape of the material of intermediate portion 522b. The inner diameter of the intermediate portion 522b is D1 or less when the probe 534 contacts the large diameter portion 30a, and D2 or less when the probe 534 contacts the small diameter portion 30b.

If P _S exceeds P _C , the sliding contact portion 534 a separates from the side surface of the endoscope 30 , so P _S must be less than or equal to P _C. P _C is represented by the following formula (6c).

where k is the spring constant of spring 535, x is the length of change of spring 535, and _rC is the radius of spring 535. However, the changed length of the spring 535 is the displacement of the spring 535 from its natural length.

When the elasticity and deformation amount of the spring 535, the material and shape of the airtight balloon 522, and the volume V of the gas to be injected into the variable volume portion 531 are determined so as to satisfy the expression (6a), as shown in FIG. With the sliding contact portion 534a in contact with the large-diameter portion 30a, the intermediate portion 522b of the airtight balloon 522 presses the large-diameter portion 30a, and the circumference of the large-diameter portion 30a is airtightly sealed.
As the endoscope 30 moves in the axial direction, as shown in FIG. expands further. That is, the inner diameter of the airtight balloon 522 increases as the outer diameter of the outer peripheral portion of the endoscope 30 inserted through the cylindrical frame portion 521 increases, and decreases as the outer diameter decreases.
As a result, the intermediate portion 522b presses the small-diameter portion 30b, and the periphery of the small-diameter portion 30b is hermetically sealed.

According to the present embodiment, the expression (6a) is satisfied in the airtight valve unit 506, so that when the endoscope 30 is inserted, the movable member 533 is positioned at a position where the probe 534 comes into contact with the side surface of the endoscope 30. keep Furthermore, in this state, gas is injected into the variable volume portion 531 so as to satisfy the expression (6a). As a result, the gas moves between the space Sv and the space Sp following changes in the outer diameter of the endoscope 30 detected by the probe 534 . As a result, even if the outer diameter of the endoscope 30 changes, the amount of expansion of the intermediate portion 522b automatically follows the change in the outer diameter of the endoscope 30. Therefore, the sliding resistance hardly changes and the endoscope can be operated. The perimeter of mirror 30 is hermetically sealed.
This facilitates the insertion and removal of the endoscope 30 and prevents gas and liquid in the body from flowing back to the outside from the airtight valve unit 506 during insertion and removal.

In the above, an example in which the outer diameter of the endoscope 30 is cylindrical has been described. The same airtightness as described above can be obtained by replacing the inflated inner diameter with an equivalent diameter in consideration of the amount of protrusion of the channel tube 15 . In this case, the probe 534 is brought into contact with the outer peripheral portion of the endoscope 11 excluding the channel tube 15 .

The overtube 501 according to this embodiment is the same as the overtube 1 according to the first embodiment except that it has an airtight valve unit 506, and thus has the same effects as the first embodiment. Therefore, as in the first embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, in the present embodiment, when inserting and removing an endoscope having a non-uniform outer diameter, insertion and removal becomes easier, and backflow of gas and liquid in the body can be more reliably prevented during insertion and removal.

The cylindrical frame portion 521 in the airtight valve unit 506 is an example of a tubular portion that communicates with the main lumen at the rear end portion of the tube body.
Airtight balloon 522 is an example of an airtight balloon fixed to the inner peripheral surface of the tubular portion and expandable toward the inside of the tubular portion.
The variable volume part 531 is arranged outside the tubular part so as to communicate with the internal space of the airtight balloon formed between the airtight balloon and the inner peripheral surface, and is resistant to the pressure of the gas flowing from the outside or the internal space. This is an example of a variable volume portion in which at least the height of the outer shape in the radial direction of the tubular portion changes as the volume changes accordingly.
The connection port 521b is an example of a gas supply pipe that communicates with the inside of the variable volume portion, allows external gas to flow into the variable volume portion, and has a check valve that prevents the gas from flowing out to the outside.
The movable member 533 is an example of a movable member that is supported outside the tubular portion so as to be movable in the radial direction of the tubular portion, and whose position in the radial direction changes according to changes in the height of the variable volume portion.
The probe 534 has a slidable contact portion 534a, which is the leading end portion in the extending direction. The probe 534 is a rod-shaped probe that is fixed to a movable member, extends toward the inside of the tubular portion in the radial direction, and abuts on the outer peripheral portion of the endoscope inserted through the tubular portion at the distal end in the extending direction. For example.
The spring 535 is an example of a biasing member that biases the movable member radially toward the tubular portion so that the probe and the outer peripheral portion of the endoscope do not separate when the endoscope is inserted through the tubular portion. is.

[19th Modification]
In the overtube 501 according to the sixth embodiment, a modification (19th modification) of the airtight valve unit used in place of the airtight valve unit 506 will be described.
As shown in FIG. 1, the airtight valve unit 506A of this modified example can be used in place of the airtight valve unit 506 of the overtube 501. As shown in FIG.
Hereinafter, the points different from the sixth embodiment will be mainly described.

FIG. 97 is a schematic cross-sectional view showing a modification (nineteenth modification) of the airtight valve unit used in the endoscope overtube according to the sixth embodiment of the present invention. FIG. 98 is an operation explanatory diagram of a modified example (19th modified example) of the airtight valve unit.
As shown in FIG. 97, an airtight valve unit 506A of this modified example has a variable volume portion 531A instead of the variable volume portion 531 in the sixth embodiment.
The variable volume portion 531A is a member similar to the variable volume portion 531 except that the volume of the internal space changes by being elastically deformed by an external force. However, the variable volume portion 531A has rigidity that makes it difficult for the volume to change compared to the airtight balloon 522 .
For example, the variable volume part 531A is a cylindrical container with a side wall 531b made of a soft elastomer having higher rigidity than the intermediate part 522b.
The variable volume portion 531A is fixed to the surface 533a of the movable member 533 and the bottom surface portion 532b of the guide member 532 with the side wall 531b extending along the radial direction of the tubular frame portion 521 . At both ends of the variable volume portion 531A in the radial direction, the opening 521f of the connection port 521b and the pipe line 536 are opened, similarly to the variable volume portion 531. As shown in FIG.
For example, when the movable member 533 moves in the radial direction and compressive force acts on the variable volume portion 531A, the sidewall 531b is compressed as shown in FIG. The volume of space Sv is reduced.
Conversely, when the movable member 533 moves in the radial direction and a tensile force acts on the variable volume portion 531A, as shown in FIG. , the volume of the space Sv increases.
Depending on the material of the side wall 531b, the thickness of the side wall 531b changes as it expands and contracts. In this case, side wall 531b is compressed to reduce the inner diameter and stretched to increase the inner diameter. That is, the increase/decrease in the inner diameter of the side wall 531b corresponds to the increase/decrease in length.

As in the sixth embodiment, the airtight valve unit 506A satisfies the following formula (6e) in order to change the space Sp of the intermediate portion 522b following changes in the outer diameter of the endoscope 30. Hereinafter, description of variables common to the above equations (6a) to (6d) will be omitted.

Here, Pb is the pressure in the radial direction (moving direction of the movable member 533) caused by the elastic deformation of the variable volume portion _531A .
Pb is represented by the following formula (6f) based on the distortion of the variable volume portion _531A during compression.

Here, _Eb is the Young's modulus of the material of the sidewall _531b in the variable volume portion 531A, Lb is the natural length of the sidewall _531b , and ΔLb is the changed length of the sidewall 531b.

P _t , P _S , and P _C are represented by formulas (6b), (6c), and (6d), respectively.
However, when the inner diameter of the side wall 531b changes, r _b in equation (6c) changes according to the deformation of the variable volume portion 531A.

In this modification, the volume is changed by elastically deforming the volume variable portion 531A. Therefore, in equation (6e), the pressure Pb required for elastic deformation of the variable volume portion 531A is considered as a condition for bringing the probe 534 into contact with the side surface of the endoscope 30. _FIG .
Thus, the overtube 501 having the airtight valve unit 506A of this modified example has the same effect as the overtube 501 according to the sixth embodiment even if the variable volume portion 531A is elastically deformed.

The variable volume portion 531A is arranged outside the tubular portion so as to communicate with the internal space of the airtight balloon formed between the airtight balloon and the inner peripheral surface, and is resistant to the pressure of the gas flowing from the outside or the internal space. This is an example of a variable volume portion in which at least the height of the outer shape in the radial direction of the tubular portion changes as the volume changes accordingly.

[Twentieth Modification]
A modification (twentieth modification) of the airtight valve unit used in place of the airtight valve unit 506 in the overtube 501 according to the sixth embodiment will be described.
As shown in FIG. 1, the airtight valve unit 506B of this modified example can be used in place of the airtight valve unit 506 of the overtube 501. As shown in FIG.
FIG. 99 is a schematic cross-sectional view showing a modification (twentieth modification) of the airtight valve unit used in the endoscope overtube according to the sixth embodiment of the present invention.
As shown in FIG. 99, the airtight valve unit 506B of this modified example is the same as the airtight valve unit 506A of the nineteenth modified example except that the spring 535 is omitted.
The following description will focus on the differences from the nineteenth modification.

In this modified example, since the spring 535 is not provided, the variable volume portion 531A functions as an elastic member that urges the movable member 533 in the radial direction toward the cylindrical frame portion 521 .
Gas is injected into the variable volume portion 531A, and when the sliding contact portion 534a of the probe 534 comes into contact with the small diameter portion 30b, the intermediate portion 522b airtightly seals the periphery of the small diameter portion 30b and the variable volume portion 531A. A tensile stress is applied to the side wall 531b of the . As a result, the movable member 533 is radially biased toward the cylinder frame portion 521 .

From this state, for example, when the large-diameter portion 30a moves to the rear end side, the probe 534 is pressed radially outward by the large-diameter portion 30a, and the movable member 533 moves radially outward. As a result, the variable volume portion 531A is stretched to increase the volume of the space Sv. As a result, the gas in the space Sp moves to the space Sv, so that the intermediate portion 522b shrinks and the inner diameter of the intermediate portion 522b expands.
As a result, the inner diameter of the intermediate portion 522b is enlarged to a size that can hermetically seal the large diameter portion 30a with a small sliding load.

Such an airtight valve unit 506B satisfies the following formula (6f). Hereinafter, description of variables common to the above equations (6a) to (6d) will be omitted.

Here, Pb is obtained by equation ( _6f ) in the nineteenth modification.

In this modification, the variable volume portion 531A also functions as a spring 535, and follows changes in the inner diameter of the intermediate portion 522b, the internal pressure of the space Sp, and the outer diameter of the endoscope 30, as in the 19th modification. This is an example of changing by
As a result, the overtube 501 having the airtight valve unit 506B of this modification has the same effect as the overtube 501 according to the sixth embodiment even if the variable volume portion 531A is elastically deformed.

[Seventh Embodiment]
An endoscope overtube according to a seventh embodiment of the present invention will be described.
FIG. 100 is a schematic perspective view showing an example of an endoscope overtube according to the seventh embodiment of the present invention. 101 is a cross-sectional view taken along line F101-F101 in FIG. 100. FIG. 102 is a cross-sectional view taken along line F102-F102 in FIG. 101. FIG. 103 is a cross-sectional view taken along line F103-F103 in FIG. 101. FIG.

An overtube 601 shown in FIG. 100 is an example of an endoscope overtube according to this embodiment.
The overtube 601 has the tip 4 removed from the overtube 1 according to the first embodiment, and instead of the fixation balloon 3, the main tube 2, the grip portion 5, the airflow tube 9, and the air supply device 10, It has a tip fixing portion 603 , a main tube 602 (tube body), a grip portion 605 , an airflow tube 609 and an air supply device 610 .
However, FIGS. 100 to 103 show the shape of the distal end fixing portion 603 in the expanded state, as in the first embodiment.
The following description will focus on the differences from the first embodiment.

As shown in FIG. 101, the distal end fixing portion 603 in this embodiment has a first fixing portion 617, a second fixing portion 618, a first supporting member 619, and a second supporting member 620.

The first fixing section 617 has a tube member 621 and a first balloon 622 (distal balloon).
The tube member 621 is a circular tube having an internal space through which the distal end portion of the endoscope that is inserted through the overtube 601 can be inserted. The inner diameter of the inner peripheral surface 621a of the tube member 621 is equal to or larger than the inner diameter of the first lumen 2c in the main tube 602, which will be described later, and is smaller than the inner diameter of the lumen into which the overtube 601 is inserted.
The outer diameter of the outer peripheral surface 621b of the tube member 621 is smaller than the inner diameter of the lumen into which the overtube 601 is inserted, and is of a size that facilitates insertion into the lumen to be treated, similar to the main tube 602 described later. . An example in which the outer diameter of the outer peripheral surface 621b is substantially equal to the outer diameter of the main tube 602 described later will be described below. A first balloon 622, which will be described later, is fixed to the outer peripheral surface 621b.
The length of the pipe member 621 is not particularly limited as long as both ends in the axial direction of the first balloon 622 described below can be fixed. For example, the length of the tubular member 621 may be 20 mm or more and 70 mm or less.

The material of the pipe member 621 may be, for example, the same material as the main tube 2 in the first embodiment.

An opening 622f communicating with the internal space of the first support member 619 is formed in the second cylindrical portion 622c at the joint with the first support member 619, which will be described later. The opening 622f is formed of a through hole penetrating through the second cylindrical portion 622c in the thickness direction.

The first balloon 622 airtightly covers the outer peripheral surface 621b of the tubular member 621 . The first balloon 622 is formed in the same manner as the fixation balloon 3 in the first embodiment except that it has an axial length for airtightly covering the outer peripheral surface 621b.
The first balloon 622 has a second cylindrical portion 622c instead of the second cylindrical portion 3c of the fixation balloon 3. As shown in FIG. The length of the second cylindrical portion 622c in the axial direction may be, for example, 10 mm or more and 60 mm or less.

The first cylindrical portion 3a and the third cylindrical portion 3e of the first balloon 622 are formed on the outer peripheral surface 621b in the same manner as the first cylindrical portion 3a and the third cylindrical portion 3e of the fixing balloon 3 in the first embodiment. Fixed. As a result, a space S61 through which gas can flow through the opening 622f is formed inside the first balloon 622 whose inner peripheral portion is closed by the outer peripheral surface 621b.
As in the first embodiment, the gas is not particularly limited, but hereinafter, unless otherwise specified, an example in which the gas is air will be described.
Similar to the fixing balloon 3, the first balloon 622 can be expanded in diameter as shown in FIG. take.

The second fixing portion 618 is formed by a second balloon 623 (fixing balloon) fixed to the distal end portion of the main tube 602, which will be described later.
The second balloon 623 hermetically covers the outer peripheral surface 2d of the main tube 602 . The second balloon 623 is formed similarly to the fixation balloon 3 in the first embodiment, except that it may have a different axial length than the fixation balloon 3 .
The second balloon 623 has a second cylindrical portion 623c instead of the second cylindrical portion 3c of the fixation balloon 3 . The length of the second cylindrical portion 623c in the axial direction may be, for example, 10 mm or more and 60 mm or less.

The first cylindrical portion 3a and the third cylindrical portion 3e of the second balloon 623 are formed on the main tube 602 in the same manner as the first cylindrical portion 3a and the third cylindrical portion 3e of the fixing balloon 3 in the first embodiment. It is fixed to the outer peripheral surface 2d. As a result, a space S62 is formed inside the second balloon 623 closed by the outer peripheral surface 2d of the main tube 602. As shown in FIG. The space S62 communicates with the second lumen 2e through an opening 2f formed in the main tube 602 similarly to the first embodiment so as to communicate with the second lumen 2e.
The second balloon 623 assumes a diameter-expanded state as shown in FIG. 101 and a diameter-reduced state (not shown) according to the internal pressure of the space S62. The internal pressure of the space S62 is determined by the amount of air supplied from the second lumen 2e through the opening 2f.

The first support member 619 consists of a tube with a closed tip 619c. Inside the first support member 619, an air supply lumen 619a extending in the longitudinal direction of the first support member 619 is formed.
The air supply lumen 619a distributes air for expanding and contracting the first balloon 622 to the space S61. An opening 619 b is formed in the air supply lumen 619 a at a position facing the opening 622 f of the first balloon 622 at the distal end of the first support member 619 . The opening 622f and the opening 619b allow the air supply lumen 619a and the space S61 to communicate with each other.

The first support member 619 has a front end portion 619A and a rear end portion 619B (air supply tube).
The distal end portion 619A of the first support member 619 connects the second cylindrical portion 622c of the first balloon 622 and the second cylindrical portion 623c of the second balloon 623 in the axial direction. In the example shown in FIGS. 101 and 102, the tip portion 619A is joined to the outside of the second cylindrical portion 622c and the second cylindrical portion 623c. The joining method of the tip portion 619A is not particularly limited. For example, the tip portion 619A may be joined to the second cylindrical portion 622c and the second cylindrical portion 623c by gluing, welding, or the like.
In the example shown in FIG. 101, the tip portion 619A is joined to the second cylindrical portion 622c and the second cylindrical portion 623c across the entirety of the second cylindrical portion 622c and the second cylindrical portion 623c in the axial direction. In the case where the required joint strength is obtained, the tip portion 619A may be joined to a portion of the second cylindrical portion 622c and the second cylindrical portion 623c at one or more points in the axial direction.

A distal end portion 619A of the first support member 619 connects the first balloon 622 and the second balloon 623 such that the first balloon 622 and the second balloon 623 are separated from each other by a certain distance in the axial direction. The distance in the axial direction between the first balloon 622 and the second balloon 623 is the distance between the first balloon 622 and the second balloon 623 necessary for surgery performed with an endoscope inserted through the overtube 601 . It is the distance that secures the size of the field.
For example, in order to allow the distal end portion 12 of the endoscope 11 to move over a wide range by operating the bending portion 17, the distance Lf in the axial direction from the rear end 621c of the tubular member 621 to the distal end 602g of the main tube 602 is , is longer than the length of the curved portion 17 .
For example, when the overtube 601 is used for endoscopic full-thickness resection of the intestinal wall of the large intestine, a necessary surgical field can be secured if the distance Lf is 70 mm or more and 120 mm or less.
For example, the same applies when the overtube 601 is used for ESD in the large intestine.

The rear end portion 619B has a length extending from the rear end of the front end portion 619A fixed to the second balloon 623 to the rear end side of the overtube 601 beyond the second balloon 623 .
In the example shown in FIG. 100, rear end portion 619B extends along main tube 602 to grip portion 605 . The arrangement of the rear end portion 619B will be described later in the description of the main tube 602. FIG.

However, the rear end portion 619B does not need to extend to the grip portion 605 as long as an air supply channel for supplying air to the first balloon 622 can be formed. In this case, an air supply tube extending along the main tube 602 to the grip portion 605 is connected to the rear end of the rear end portion 619B. The insufflation tube has a longitudinally extending insufflation lumen. The air supply tube is connected to the rear end of the rear end portion 619B so that its air supply lumen communicates with the air supply lumen 619a of the first support member 619. As shown in FIG.
In this case, the length of the rear end portion 619B is not particularly limited. For example, the rear end 619B may be long enough to form a connection with an insufflation tube.
An example in which the rear end portion 619B of the first support member 619 extends to the grip portion 605 as shown in FIG. 100 will be described below.

The outer diameter and inner diameter of the leading end portion 619A and the trailing end portion 619B may be equal to or different from each other. The rear end portion 619B has an outer diameter smaller than the inner diameter of an insertion lumen provided in the main tube 602, which will be described later.
For example, the outer diameter of the rear end portion 619B may be 1 mm or more and 4 mm or less.
The inner diameters of the front end portion 619A and the rear end portion 619B are not particularly limited as long as air can be supplied without any trouble. For example, the inner diameters of the leading end portion 619A and the trailing end portion 619B may be 0.5 mm or more and 2 mm or less.
Hereinafter, an example in which the outer diameter and the inner diameter of the front end portion 619A and the rear end portion 619B are equal to each other will be described unless otherwise specified.
The material of the first support member 619 is not particularly limited as long as it has flexibility to the extent that the flexibility of the main tube 602, which will be described later, is not impaired.
For example, when the outer diameter and inner diameter of the first support member 619 are within the ranges described above, suitable materials for the first support member 619 include PTFE (polytetrafluoroethylene), polycarbonate, and the like.

The second support member 620 axially connects the second cylindrical portion 622c of the first balloon 622 and the second cylindrical portion 623c of the second balloon 623 at positions different in the circumferential direction from the first support member 619. . In the example shown in FIG. 102, three second support members 620 are provided at positions that equally divide the second cylindrical portion 622c and the second cylindrical portion 623c in the enlarged diameter state into quarters along with the first support member 619 in the circumferential direction. It is
Each second support member 620 is joined to the second cylindrical portion 622c and the second cylindrical portion 623c from the outside in the same manner as the tip portion 619A of the first support member 619. As shown in FIG.

Each second support member 620 connects the first balloon 622 and the second balloon 623 to each other with a certain distance in the axial direction, similarly to the distal end portion 619A of the first support member 619 . However, each second support member 620 does not have an air supply function. Each second support member 620 may be, for example, a solid bar.
The length of each second support member 620 is not particularly limited as long as the first balloon 622 and the second balloon 623 can be connected in the same manner as the first support member 619 . In the example shown in FIG. 101, each second support member 620 is joined to the second cylindrical portion 622c and the second cylindrical portion 623c across the entirety of the second cylindrical portion 622c and the second cylindrical portion 623c in the axial direction. there is However, if the required joint strength is obtained, each second support member 620 may be joined to a portion of the second cylindrical portion 622c and the second cylindrical portion 623c at one or more points in the axial direction.

As shown in FIG. 103, the main tube 602 is the same as the main tube 2 in the first embodiment, except that an insertion lumen 602e is formed in the thick portion 2b of the main tube 2 in the first embodiment.
The insertion lumen 602e allows the first support member 619 extending to the rear end side of the second balloon 623 to be inserted. The insertion lumen 602e penetrates the main tube 602 in the axial direction. The insertion lumen 602e is parallel to the second lumen 2e at the thick portion 2b of the main tube 602 .
101, an opening 602f for inserting the first support member 619 into the insertion lumen 602e is provided at the distal end of the insertion lumen 602e at a position away from the second balloon 623 on the rear end side. is formed.
The rear end portion 619B of the first support member 619 is inserted through the insertion lumen 602e through the opening 602f, and communicates with the internal conduit of the grip portion 605, which will be described later, at the rear end of the insertion lumen 602e.

The manufacturing method of the distal end fixing portion 603 is not particularly limited, but it can be manufactured as follows, for example.
A first balloon 622 is joined to the tubular member 621 and a second balloon 623 is joined to the distal end of the main tube 602 . After that, the rear end portion 619B of the first support member 619 is inserted from the opening 602f of the main tube 602 toward the rear end. After the rear end of the rear end portion 619B reaches the position where it is joined to the grip portion 605, the front end portion 619A of the first support member 619 is aligned with the joint portion between the first balloon 622 and the second balloon 623. , respectively. At this time, the first support member 619 is arranged such that the opening 619b and the opening 622f of the first balloon 622 face each other and the opening 619b and the opening 622f communicate airtightly. Distal end 619A is joined to first balloon 622 around opening 619b and opening 622f.
After bonding the first support member 619 and the first balloon 622 and the second balloon 623 or at the same time when the first support member 619 is bonded, each second support member 620 is connected to the second support member 620 and the second balloon 623 . 1 balloon 622 and second balloon 623 are joined. However, after each second support member 620 is joined to the first balloon 622 and the second balloon 623, the first support member 619 may be joined as described above.

As shown in FIG. 100, the grip portion 605 has a connector 605c instead of the first luer connector 5c of the grip portion 5 in the first embodiment.
The connector 605c detachably connects a first connecting tube and a second connecting tube respectively communicating with the first flow path and the second flow path formed inside the grip portion 605 to an air flow tube 609 described later.
The first flow path allows the second lumen 2e (see FIG. 101) of the main tube 602 and the first connecting tube to communicate with each other.
The second channel communicates the air supply lumen 619a of the first support member 619 and the second connection pipe with each other.

The grip portion 605 and the rear end portion of the main tube 602 are connected to each other in the same manner as the grip portion 5 and the rear end portion of the main tube 2 in the first embodiment.

Airflow tube 609 extends from insufflation device 610 . A connector 609 a is provided at the tip of the airflow tube 609 to detachably connect to the first connecting tube and the second connecting tube of the grip portion 605 . The airflow tube 609 has two independent flow paths that communicate with the first connecting pipe and the second connecting pipe, respectively.
Thereby, the airflow tube 609 connected to the connector 605c forms independent air flow paths between the second lumen 2e and the air supply lumen 619a and the air supply device 610, respectively.

The air supply device 610 supplies air for expanding the diameters of the first balloon 622 and the second balloon 623, and sucks the air inside the first balloon 622 and the second balloon 623 as necessary. , is the same as the insufflation device 10 in the first embodiment.
In this embodiment, the air supply device 610 can independently change the amount of air flowing through the two channels of the airflow tube 609 based on the operator's operation. A means for changing the amount of air is not particularly limited.
For example, the air supply device 610 may have two systems of air supply units and a flow control unit that changes the flow rate of air in each of the air supply units according to the operator's operation.
For example, the air supply device 610 includes a single air supply unit, a flow control unit that changes the air flow rate in the air supply/intake unit according to the operator's operation, and a channel switching valve for the two channels. may have In this case, air can be supplied to and sucked from the flow path of the airflow tube 609 that is communicated by switching the flow path switching valve.
The air supply/intake portion of the air supply device 610 may be an electric pump or a manual pump as in the first embodiment. In the case of a manual pump, the air supply device 610 may be any air supply device including the manual air supply mechanism 211 in each of the embodiments and modifications described above, for example.

When switching the flow path to which the air is supplied and inhaled by the flow path switching valve, the flow path switching valve is not limited to the configuration for switching the flow path of the airflow tube 609 . For example, a channel switching valve may be provided on an appropriate channel between the connector 605c and the air supply device 610. In this case, in the airflow tube 609, the channel closer to the air supply device 610 than the channel switching valve should have one channel.

Here, problems in using a conventional overtube for endoscopic full-thickness resection will be described.
FIG. 104 is a schematic diagram showing an example of endoscopic full-thickness resection using a conventional overtube.

ESD, which uses an endoscope to resect the submucosa in a patient's lumen, is becoming popular.
However, ESD is inadequate, for example in the treatment of advanced cancer, and requires full-thickness resection of the lumen. In this case, full-thickness resection under an endoscope enables less invasive surgery.
104(a), (b), and (c) show treatment of the large intestine C by an endoscope 11 passing through a conventional overtube 40 having a fixing balloon 3 similar to that of the first embodiment at its tip. The step of excising the site Ts in full thickness is schematically depicted.
As shown in FIG. 104(a), an overtube 40 is inserted into the large intestine C near the treatment site Ts. The overtube 40 is fixed to the large intestine C by expanding the fixation balloon 3 . The operator inserts the endoscope 11 through the overtube 40 and places the distal end of the endoscope 11 in the vicinity of the treatment site Ts.
In this state, the operator inflates the large intestine C by supplying air from the endoscope 11 . As a result, a surgical field is secured in front of the fixation balloon 3 .

After that, as shown in FIG. 104(b), the operator uses the treatment tool passed through the treatment tool channel of the endoscope 11 to perform full-thickness excision of the treatment site Ts together with the surrounding intestinal wall Cw. . Thereby, an opening Ch is formed in the intestinal wall Cw.
In the process of forming the opening Ch, the air inside the large intestine C leaks out from the cut portion. As a result, the large intestine C is crushed by body pressure from the outside as shown in (c). (b) is a schematic diagram, and is depicted as if the operative field is secured when the opening Ch is formed. The surgical field then begins to shrink rapidly, making it difficult for the operator to continue the resection procedure. Even if the full-thickness excision can be completed, it becomes difficult to suture the opening Ch after the excision.

Thus, in the endoscopic full-thickness resection technique, securing a sufficient surgical field around the treatment site Ts during and after resection is a problem.

A method of using the overtube 601 will be described with an example of using the overtube 601 for an endoscopic full-thickness resection.
FIG. 105 is a schematic diagram showing an example of how to use the endoscope overtube according to the seventh embodiment of the present invention. 106 is an enlarged view of the F106 portion in FIG. 105. FIG. FIG. 107 is a schematic diagram showing an example of how to use the endoscope overtube according to the seventh embodiment of the present invention.
However, in FIGS. 105 to 107, the detailed shapes of the endoscope cap 13, the grasping device 14, the channel tube 15, etc. of the endoscope 11 are omitted for the sake of clarity. The same applies to the endoscope 11 in other drawings in this embodiment.

First, the overtube 601 is prepared.
The prepared overtube 601 is the same as the overtube 1 used for ESD in the first embodiment, except that the distal end fixing portion 603 is reduced in diameter like the fixation balloon 3 .
The following description focuses on points that differ from the method of using the overtube 1 described in the first embodiment.

In the prepared overtube 601 , the air in the space S61 inside the first balloon 622 is sucked out by the air supply device 610 . Therefore, the first balloon 622 is folded in the same manner as the fixing balloon 3 in the reduced diameter state in the first embodiment, and is close to the outer peripheral surface 2 d of the main tube 602 . As a result, the outer diameter of the first fixing portion 617 is reduced to substantially the same diameter as the outer diameter of the main tube 602 on which the fixing balloon 3 is not provided. This state is hereinafter referred to as the diameter-reduced state of the first balloon 622 .
Furthermore, in the overtube 601 , the air in the space S62 inside the second balloon 623 is sucked out by the air supply device 610 . Therefore, the second balloon 623 is folded like the first balloon 622 and is close to the outer peripheral surface 2 d of the main tube 602 . As a result, the outer diameter of the second fixing portion 618 is reduced to approximately the same diameter as the outer diameter of the main tube 602 . This state is hereinafter referred to as the diameter-reduced state of the second balloon 623 .
In the prepared overtube 601, the airtight valve unit 6 is made so that the insertion portion of the endoscope 11 can be inserted with low resistance, as in the first embodiment.

After that, the operator inserts the tip of the endoscope 11 inside the airtight valve unit 6 of the overtube 601 . Thereafter, the insertion portion of the endoscope 11 is passed through the grip portion 605, the first lumen 2c of the main tube 602, and the inner peripheral surface 621a of the pipe member 621, and the insertion portion of the endoscope 11 is passed through the pipe member. Extend from 621.

After that, the operator places the overtube 601 outside the patient's body, and inserts the insertion portion of the endoscope 11 protruding from the overtube 601 into the large intestine C from the anus, as in the first embodiment. After the treatment site Ts appears in the image acquired by the endoscope 11, the operator stops inserting the endoscope 11 (see FIG. 105).

After that, the operator inserts the overtube 601 into the large intestine C from the anus along the insertion portion of the endoscope 11 . At this time, air can be supplied from the airtight valve operating tube 7 to the airtight valve unit 6 (not shown) to bring the intermediate portion 22b into close contact with the outer peripheral portion of the endoscope 11, as in the first embodiment. As a result, the gap between the outer peripheral portion of the endoscope 11 and the airtight valve unit 6 is sealed airtight and liquidtight by the airtight valve unit 6 .
As the overtube 601 continues to be inserted, the intermediate portion 22b of the airtight valve unit 6 also moves distally together with the overtube 601 . At this time, even if the outer peripheral portion of the endoscope 11 has unevenness, the intermediate portion 22b is deformed according to the unevenness, so that the airtight and liquid-tight states are maintained.
In this embodiment, unlike the first embodiment, the airtight valve unit 6 (not shown) may be omitted.

The first fixing portion 617 in the distal end fixing portion 603 is connected to the second fixing portion 618 by the first supporting member 619 and the second supporting member 620 having flexibility. Therefore, by bending the first support member 619 and the second support member 620, the distal end fixing portion 603 can smoothly move along the bending portion and the bending portion of the endoscope 11 inserted in a bent state. .

As shown in FIG. 106, when the first balloon 622 and the second balloon 623 are in a contracted state, the outer diameter of the distal end fixing portion 603 is approximately the same as the outer diameter of the main tube 602, and is equal to the inner diameter of the intestinal wall Cw. small enough for
In the diameter-reduced state, the first support member 619 and the second support members 620 extend in the axial direction of the overtube 601 at the outermost peripheral portion of the distal end fixing portion 603 . Therefore, when the overtube 601 moves along the endoscope 11 and the distal end fixing portion 603 contacts the intestinal wall Cw, the first support member 619 and the second support members 620 of the distal end fixing portion 603 are is in linear contact with the intestinal wall Cw as a linear body extending in the moving direction, so the sliding resistance with the intestinal wall Cw is reduced. Further, the tip portion 619A of the first support member 619 and each of the second support members 620 protrude further to the outer peripheral side than the rear end 621c of the pipe member 621 and the tip 602g of the main tube 602. As a result, the distal end portion 619A of the first support member 619 or the second support member 620 contacts the intestinal wall Cw first, so that the rear end 621c and the distal end 602g contact the intestinal wall Cw while the overtube 601 is moving. is suppressed. In this respect as well, the sliding resistance is reduced and the load on the patient is reduced.

The operator inserts the overtube 601 until the distal end fixing portion 603 is positioned near the rear end of the distal end portion 12 of the endoscope 11, as indicated by a two-dot chain line in FIG.
After that, as shown in FIG. 107, the operator pushes the overtube 601 further distally so that the tip portion 12 is positioned between the first fixing portion 617 and the second fixing portion 618 .

108 is an enlarged view of the F108 portion in FIG. 107. FIG. 109 to 110 are cross-sectional views showing an example of how to use the endoscope overtube according to the seventh embodiment of the present invention.
In the state shown in FIG. 108, the operator looks at the image from the endoscope 11, and when the first balloon 622 and the second balloon 623 are expanded in diameter, the distal end portion 619A of the first support member 619 and the second balloon 623 are expanded. It is confirmed whether any one of the two support members 620 is located across the treatment site Ts.
If there is a possibility that either the distal end portion 619A of the first support member 619 or the second support member 620 straddles the treatment site Ts when the diameter-expanded state is formed, the operator must use the overtube 601 outside the body. is rotated in the circumferential direction to shift the positions of the tip portion 619A of the first support member 619 and the second support member 620 in the circumferential direction. At this time, the operator fixes the endoscope 11 and rotates the grip portion 605 of the overtube 601 around the endoscope 11 . At this time, the intermediate portion 22b of the airtight valve unit 6 (not shown) can rotate smoothly along the outer periphery of the endoscope 11 while maintaining airtightness and liquidtightness.
Rotation of the grip part 605 is transmitted to the distal end fixing part 603 according to the torsional rigidity of the main tube 602 . As a result, the distal end portion 619A of the first support member 619 and the second support member 620 rotate in the same direction as the grip portion 605 rotates.
However, if there is no possibility that either the distal end portion 619A of the first support member 619 or the second support member 620 straddles the treatment site Ts, it is not necessary to rotate the overtube 601 in the circumferential direction.
This completes the position adjustment of the distal end fixing portion 603 in the circumferential direction.

The circumferential position adjustment of the distal end fixing portion 603 may be performed after the diameters of the first balloon 622 and the second balloon 623 are expanded to near the inner diameter of the intestinal wall Cw. In this case, even if the distal end fixing portion 603 moves around during rotation, the outer peripheral portions of the first balloon 622 and the second balloon 623 slide smoothly on the inner surface of the intestinal wall Cw. Circumferential position adjustment can be performed in a state in which the center is substantially aligned with the center of the intestinal wall Cw.
Furthermore, since the radial positions of the distal end portion 619A of the first support member 619 and the second support member 620 are close to the positions when the distal end fixing portion 603 is fixed to the intestinal wall Cw, the first support in the expanded diameter state is achieved. Displacement in the circumferential direction of the distal end portion 619A of the member 619 and the second support member 620 is unlikely to occur.

After completing the circumferential position adjustment of the distal end fixing portion 603, the operator operates the air supply device 610 to supply air to the first balloon 622 and the second balloon 623 to inflate them.
At this time, the air from the air supply device 610 is independently supplied to the first balloon 622 and the second balloon 623 according to the configuration of the air supply device 610 .
When the first balloon 622 and the second balloon 623 are sufficiently inflated, each comes into contact with the inner surface of the intestinal wall Cw. The second cylindrical portion 622c of the first balloon 622, the second cylindrical portion 623c of the second balloon 623, the distal end portion 619A of the first support member 619 fixed to the outer peripheral side of each, and each of the second support members 620 presses the inner wall of the intestinal wall Cw.
As a result, the distal end fixing portion 603 is fixed to the intestinal wall Cw to such an extent that it does not easily move relative to the large intestine C. As shown in FIG.

The first balloon 622 and the second balloon 623 may be inflated simultaneously, or may be inflated with a time lag.
When inflating with a time lag, it is more preferable to inflate the first balloon 622 on the distal side and then inflate the second balloon 623 on the proximal side.
In this case, after inflating the first balloon 622 to fix the first fixing part 617 to the intestinal wall Cw, the operator may pull the main tube 602 proximally and then inflate the second balloon 623. . According to this procedure, even if the distal end portion 619A of the first supporting member 619 and the second supporting member 620 are flexed or curved, the distal end portion 619A of the first supporting member 619 and the second supporting member 620 are axially aligned. stretched in the direction As a result, the bending or bending of the distal end portion 619A of the first support member 619 and the second support member 620 is corrected.
When the position of the second balloon 623 in the axial direction is fixed while the distal end portion 619A of the first support member 619 and the second support member 620 are bent or curved, the rear end 621c of the tube member 621 and the main tube are aligned. The distance between the tip 602g of 602 becomes shorter than Lf, and the surgical field in the axial direction becomes narrower.
On the other hand, when the deflection or curvature is corrected, the distance between trailing edge 621c and leading edge 602g can be restored up to Lf.
After increasing the distance between the rear end 621c and the distal end 602g, the operator inflates the second balloon 623 to fix the second fixing portion 618 to the intestinal wall Cw.

When the tip fixing part 603 is fixed to the intestinal wall Cw, it is surrounded by the first supporting member 619 and the second supporting members 620 inside the intestinal wall Cw between the first fixing part 617 and the second fixing part 618. A space Sf is formed.
The distal end portion 12 of the endoscope 11 and the treatment tool M extending from the treatment tool channel of the distal end portion 12 are movable inside the space Sf. As the treatment tool M, for example, a high-frequency knife may be used.
The space Sf forms an operating field for performing full-thickness resection.
The intestinal walls Cw on the distal and proximal sides of the space Sf are radially supported by the first balloon 622 and the second balloon 623 . As a result, the intestinal wall Cw expands to a size equal to the outer diameters of the first balloon 622 and the second balloon 623 . Between the first balloon 622 and the second balloon 623, the distal end portion 619A of the first support member 619 and the second support member 620 are stretched.
Therefore, the intestinal wall Cw between the first balloon 622 and the second balloon 623 is radially supported by the distal end portion 619A of the first support member 619b and the second support members 620. As shown in FIG.
Therefore, the space Sf can have a constant volume without being expanded by introducing air. As a result, treatment can be performed without sending air into the large intestine C to inflate the large intestine C, so that the burden on the patient can be reduced.

The operator uses, for example, the treatment tool M projected from the endoscope 11 to resect the entire thickness of the intestinal wall Cw around the treatment site Ts.
At this time, if a through-hole is formed in the intestinal wall Cw, as shown in FIG. 110, the gas and liquid in the large intestine C leak to the outside of the large intestine C, so the large intestine C is pressed from the outside. However, since the intestinal wall Cw is supported from the inside by the distal end fixing portion 603, it will not collapse. For example, even if the space Sf is reduced, a polygonal cross-sectional shape with the first support member 619 and each of the second support members 620 as vertices is ensured.
As a result, even if a through-hole is formed in the intestinal wall Cw, an operation field of a size similar to that before the through-hole is formed is secured.
In the space Sf secured by the distal end fixing portion 603, the operator can continue treatment after full-thickness excision, such as suturing the opening Ch, using an appropriate treatment tool.

After completing all necessary procedures for endoscopic full-thickness resection, the operator operates the air supply device 610 to suck out the air in the first balloon 622 and the second balloon 623 . As a result, the diameters of the first balloon 622 and the second balloon 623 are reduced.
After that, the operator pulls out the endoscope 11 and the overtube 601 from the anus.
Endoscopic full-thickness resection using the overtube 601 is thus completed.

The method of using the overtube 601 has been described above with an example of endoscopic full-thickness resection. However, the overtube 601 may be used for treatments other than endoscopic full-thickness resection as long as it is an endoscopic treatment that can be performed using the space Sf as an operating field. For example, it may be used for ESD, EMR (endoscopic mucosal resection), polypectomy, and the like.

An overtube 601 according to this embodiment is different from the overtube 1 according to the first embodiment mainly in that it has a distal end fixing portion 603 instead of the fixing balloon 3 . The difference between the main tube 2, the grip portion 5, the airflow tube 9, and the air supply device 10 and the main tube 602, the grip portion 605, the airflow tube 609, and the air supply device 610 in this embodiment is that the distal end fixing portion 603 is It arises by having a first balloon 622 and a second balloon 623 .
Therefore, the overtube 601 is similar to the overtube 1 except that it has a first balloon 622 , a second balloon 623 , a first support member 619 , and a second support member 620 instead of the fixation balloon 3 . Since it is configured similarly, it has the same function as the first embodiment. Therefore, according to the present embodiment, as in the first embodiment, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.
In particular, in this embodiment, since the distal end fixing portion 603 is provided, even if a through-hole is formed in the inner wall of the lumen to be treated in front of the main tube 602, the space Sf serving as the surgical field can be formed. Various procedures are readily performed, including endoscopic full-thickness resection.

[21st Modification]
A modification (21st modification) in the method of using the overtube 601 will be described.
111 to 113 are cross-sectional views showing a modification (21st modification) of the method of using the endoscope overtube according to the seventh embodiment of the present invention.
This modification is a modification relating to the method of inserting the overtube 601 .
In the following, the points different from the seventh embodiment will be mainly described.

As shown in FIG. 111, in the method of use of this modified example, the overtube 601 is such that the bending portion 17 and the distal end portion 12 of the endoscope 11 protrude distally from the tubular member 621 of the first fixing portion 617. In this state, the endoscope 11 is inserted and prepared. The distal end fixing portion 603 of the overtube 601 is in a diameter-reduced state similar to that of the seventh embodiment.
The overtube 601 is inserted into the large intestine C from the patient's anus together with the endoscope 11 while maintaining a constant amount of protrusion of the endoscope 11 from the tubular member 621 .

After the treatment site Ts appears in the image acquired by the endoscope 11, the operator stops inserting the endoscope 11 and the overtube 601 as shown in FIG. This state is substantially the same as the state in which the overtube 601 is inserted close to the treatment site Ts in the seventh embodiment (see two-dot chain line in FIG. 105).
After that, as in the seventh embodiment, the operator moves the overtube 601 further distally so that the distal end portion 12 is positioned between the first fixing portion 617 and the second fixing portion 618. push in.
After that, as shown in FIG. 113, the operator inflates the first balloon 622 and the second balloon 623 of the distal end fixing section 603 to move the distal end fixing section 603 to the large intestine in the same manner as in the seventh embodiment. Fix to the inner wall of C.
Thereafter, the operator performs necessary treatment and removal of the endoscope 11 and overtube 601 after the treatment in the same manner as in the seventh embodiment.

According to this modified example, only the method of inserting the overtube 601 is different, so the treatment after insertion is performed in the same manner as for the overtube 601 . Therefore, this modified example has the same effect as the seventh embodiment.
In particular, according to this modification, since the overtube 601 is inserted into the lumen to be treated together with the endoscope 11, the lengths of both the endoscope 11 and the overtube 601 are adjusted from the insertion port to the position of the treatment target. It should be slightly longer than the length up to Therefore, compared to the case where the endoscope 11 is placed near the treatment target and then the overtube 601 is inserted using the endoscope 11 as a guide, the length of the endoscope 11 can be shortened.

[22nd Modification]
In the overtube 601 according to the seventh embodiment, a modified example (22nd modified example) of the distal end fixing portion used in place of the distal end fixing portion 603 will be described.
As shown in FIG. 100, the distal end fixing portion 603A of this modified example can be used in place of the distal end fixing portion 603 of the overtube 601. As shown in FIG.
In the following, the points different from the seventh embodiment will be mainly described.

FIG. 114 is a cross-sectional view showing a modification (22nd modification) of the distal end fixing portion used in the endoscope overtube of the seventh embodiment of the present invention. FIG. 115 is a cross-sectional view showing the action of the modified example (22nd modified example) of the distal end fixing portion.
As shown in FIG. 114, the distal end fixing portion 603A is similar to the distal end fixing portion 603 except that the first support member 619 and the second support members 620 are arranged differently in the circumferential direction.
The first support member 619 and each of the second support members 620 in the distal end fixing portion 603A are arranged at positions that do not equally divide the circumferential direction of the second cylindrical portion 622c of the first balloon 622 in the expanded diameter state. In the example shown in FIG. 114, the central angles of the circumferential arrangement of the first support member 619 and each of the second support members 620 measured clockwise from the first support member 619 are, for example, β1, β1, β1, and β2. where 3×β1+β2 equals 360° and β2 is an acute angle. This makes β1 greater than β2.

The distance between the distal end portion 619A of the first support member 619 and the second support member 620, which are adjacent to each other in the circumferential direction, and the second support members 620, which are adjacent to each other in the circumferential direction, is the center angle of each. proportional. As a result, when the diameter of the distal end fixing portion 603A is expanded, the circumferential distance between the distal end portion 619A and the second support member 620 and the second support members 620 is a circle because they are separated by the central angle β1. A wide opening Ow wider than a quarter of the circumference is formed respectively. On the other hand, between the tip portion 619A and the second support member 620 separated by the central angle β2, an opening On is formed with a narrower interval in the circumferential direction than the wide opening Ow.

According to the distal end fixing section 603A, when rotating the distal end fixing section 603A to a position where the distal end portion 619A of the first support member 619 and the second support member 620 do not straddle the treatment site Ts, the treatment site Ts is moved by 3 degrees. The distal end fixing portion 603A is rotated so as to face one of the two wide openings Ow. As a result, the distal end fixing portion 603A can be arranged so as not to straddle the treatment site Ts and have a size exceeding a quarter of the inner peripheral surface of the intestinal wall Cw.
Furthermore, as shown in FIG. 115, when the treatment site Ts has a size that does not exceed a quarter of the inner peripheral surface of the lumen, the treatment site Ts can be placed more freely in the wide opening Ow. Even if the rotation accuracy of the fixing part 603A is low, it is easy to arrange the treatment site Ts at a position not straddling it, for example, as indicated by the two-dot chain line. Therefore, redoing of the fixing operation of the distal end fixing portion 603A can be reduced.
According to the distal end fixing portion 603A, the distal end fixing portion 603A can be quickly fixed so as not to straddle various treatment sites Ts, which facilitates operator's operation.

The distal end fixing portion 603A of this modified example is different from the distal end fixing portion 603 of the seventh embodiment except that the distal end portion 619A of the first support member 619 and the second support members 620 have different circumferential intervals. It is the same. Therefore, the overtube 601 having the distal end fixing portion 603A has the same function as in the seventh embodiment.
In particular, according to the distal end fixing portion 603A of this modified example, the distal end fixing portion 603A is positioned so as to avoid the treatment site Ts so that the first support member 619 and each second support member 620 do not straddle various treatment sites Ts. Since it can be quickly fixed, it is easy for the operator to quickly perform the procedure.

[23rd Modification]
In the overtube 601 according to the seventh embodiment, a modified example (22nd modified example) of the distal end fixing portion used in place of the distal end fixing portion 603 will be described.
As shown in FIG. 100, the distal end fixing portion 603B of this modified example can be used in place of the distal end fixing portion 603 of the overtube 61. As shown in FIG.
In the following, the points different from the seventh embodiment will be mainly described.

FIG. 116 is a schematic cross-sectional view showing a modification (twenty-third modification) of the distal end fixing portion used in the endoscope overtube according to the seventh embodiment of the present invention. 117 is a cross-sectional view taken along line F117-F117 in FIG. 116. FIG. FIG. 118 is a schematic cross-sectional view showing an example of a diameter-reduced state of a modification (twenty-third modification) of the distal end fixing portion.

As shown in FIG. 116, the distal end fixing portion 603B is similar to the distal end fixing portion 603 except that it has a first fixing portion 617B instead of the first fixing portion 617 of the distal end fixing portion 603 in the seventh embodiment. It is the same.
In the following, the points different from the seventh embodiment will be mainly described.

The first fixing portion 617B has a first balloon 622B instead of the first balloon 622 and the tube member 621 in the first fixing portion 617. As shown in FIG.
The first balloon 622B has a first cylindrical surface portion 622g, a second cylindrical surface portion 622c, a front end surface portion 622b, and a rear end surface portion 622d. However, the first balloon 622B indicated by solid lines in FIGS. 116 and 117 is in an enlarged diameter state in which the outer diameter of the first balloon 622B is enlarged to a state in which it can be fixed to the lumen to be treated (hereinafter referred to as expanded diameter when fixed). state).
On the other hand, the shape of the first balloon 622B indicated by two-dot chain lines in FIGS. 116 and 117 shows a state in which the diameter is expanded in a natural state in which no tension is generated (hereinafter referred to as a "natural diameter expansion state").
In the naturally expanded state, the first balloon 622B has an annular shape when viewed from the axial direction.
Hereinafter, unless otherwise specified, the shape of the first balloon 622B in the naturally expanded state will be described.

As indicated by a two-dot chain line in FIG. 116, the first cylindrical surface portion 622g has a substantially cylindrical shape extending in the axial direction toward the center of the first balloon 622B. The inner diameter of the first cylindrical surface portion 622g is the same as that of the inner peripheral surface 621a of the pipe member 621 . Therefore, the endoscope 11 can be inserted through the inside of the first cylindrical surface portion 622g.
The second cylindrical portion 622c has the same cylindrical shape as the first balloon 622 in the seventh embodiment, and is arranged coaxially with the first cylindrical surface portion 622g. An opening 622f similar to that of the first balloon 622 is engaged with the second cylindrical portion 622c.
The outer diameter of the second cylindrical portion 622c is larger than the outer diameter of the outer peripheral surface 621b, and is not particularly limited as long as it is a size that allows expansion beyond the outer diameter that can be fixed in the lumen to be treated.

As shown in FIG. 116, the tip surface portion 622b extends radially and circumferentially between the tips of the first cylindrical surface portion 622g and the second cylindrical portion 622c.
The rear end surface portion 622d extends radially and circumferentially between the respective rear ends of the first cylindrical surface portion 622g and the second cylindrical portion 622c.
A ring-shaped space S63 is formed inside the first balloon 622B having such a configuration in a naturally expanded state.

On the second cylindrical portion 622c of the first balloon 622B, similarly to the first balloon 622, the distal end portion 619A of the first support member 619 and the three second support members 620 are fixed.
Similarly to the first balloon 622, the opening 622f of the first balloon 622B communicates with the opening 619b of the first support member 619 while keeping the surrounding airtight.
As a result, air can be supplied from the air supply device 610 and air can be inhaled using the air supply device 610 through the air supply lumen 619a of the first support member 619 inside the first balloon 622B. .

A material similar to that of the first balloon 622 may be used as the material of the first balloon 622B.

The first balloon 622B expands and contracts according to the amount of air that is supplied to the inside of the first balloon 622B from the opening 622f. For example, when atmospheric pressure air having a volume equal to the volume of the first balloon 622B is supplied, the first balloon 622B is naturally expanded.
When air is further supplied, the diameter of the first balloon 622B expands to a size that balances with the atmospheric pressure. For example, as shown in FIG. 117, the second cylindrical portion 622c expands from the cylinder indicated by the dashed line to a substantially cylindrical shape with a larger diameter.
On the other hand, since the first cylindrical surface portion 622g expands radially inward, it deforms such that the inner diameter of the tip surface portion 622b is reduced. When the diameter of the first cylindrical surface portion 622g is reduced to some extent, the inner opening of the first cylindrical surface portion 622g is radially crushed according to the pressure balance during air supply. As a result, the through-hole in the axial direction of the first balloon 622B is closed in the diameter-expanded state when fixed.
In the example shown by the solid line in FIG. 117, the first cylindrical surface portion 622g of the first balloon 622B is flattened in the vertical direction in the drawing in the diameter expanded state at the time of fixation, and is linearly closed. However, the way the first cylindrical surface portion 622g is crushed is not limited to the horizontal line as shown in the drawing, and may be, for example, a vertical line, a cross, or a radial shape.

When air is sucked from the space S63, as shown in FIG. 118, the folded second cylindrical portion 622c is in close contact with the outer circumference of the first cylindrical surface portion 622g. The tip portion 619A fixed to the second cylindrical portion 622c and each of the second support members 620 are close to the outer peripheral portion of the first cylindrical surface portion 622g together with the second cylindrical portion 622c.
As a result, the first fixing portion 617B is contracted into a cylindrical shape having a slightly larger diameter than the inner diameter of the first cylindrical surface portion 622g in the naturally expanded state. A through hole extending in the axial direction is formed inside the cylindrical first cylindrical surface portion 622g at the center portion of the first fixing portion 617B in a diameter-reduced state. The inner diameter of the through-hole is equal to the inner diameter of the first cylindrical surface portion 622g in the naturally expanded state.

The distal end fixing portion 603B of this modified example is the same as the distal end fixing portion 603 except that it has a first fixing portion 617B instead of the first fixing portion 617, and thus has the same effects as in the seventh embodiment.
In particular, when the first balloon 622B and the second balloon 623 are contracted, the distal end fixing portion 603B of this modified example has a cylindrical shape with a diameter slightly larger than the inner diameter of the first cylindrical surface portion 622g. Therefore, in the diameter-reduced state, it can be inserted into and removed from the lumen to be treated along or together with the endoscope 11 in the same manner as the overtube 601 having the distal end fixing portion 603 .
At this time, since the first fixing portion 617B is formed by the first balloon 622B, the first cylindrical portion 3a and the third cylindrical portion 3e for fixing to the pipe member 621 are unnecessary. Furthermore, the pipe member 621 for fixing the first cylindrical portion 3a and the third cylindrical portion 3e is also unnecessary.
Therefore, the first fixing portion 617B can have a smaller thickness in the axial direction than the first fixing portion 617 does. Thereby, even if the width of the second cylindrical portion 622c is the same, the axial thickness of the first fixing portion 617B is smaller than that of the first fixing portion 617. As shown in FIG.
In this modified example, the thickness of the first fixing portion 617B in the axial direction can be made thinner than that of the first fixing portion 617. Therefore, compared to the first fixing portion 617, the bending portion and the bending portion of the endoscope 11 are more flexible. can move along the endoscope 11 more smoothly when the radius of curvature of is small.
Furthermore, since the pipe member 621 becomes unnecessary, the number of parts can be reduced. This makes it possible to reduce the weight of the distal end fixing portion 603B and the cost of parts.

In this modified example, the central through-hole of the first fixing portion 617 is closed in the expanded diameter state for fixing the distal end fixing portion 603B to the lumen to be treated.
This suppresses the flow of gas and liquid between the inner space of the lumen on the distal side of the first fixing portion 617B and the inner space of the lumen on the proximal side of the first fixing portion 617B. As a result, the surgical field between the first fixing part 617B and the second fixing part 618 is isolated from the lumen on the more distal side, so that the distal lumen is less likely to be affected by the treatment. .
When the overtube 601 having the distal end fixing portion 603B is removed from the lumen, air is sucked from the space S63 to form a diameter-reduced state. As a result, if the overtube 601 is pulled toward the rear end side of the distal end portion 12 of the endoscope 11, and the endoscope 11 is inserted through the first cylindrical surface portion 622g, the endoscope 11 can be viewed in the same manner as during insertion. The overtube 601 is removed from the body together with the mirror 11 .

The seventh embodiment and each modified example described above may be implemented with various modifications.
For example, the number of the second support members 620 is such that the interval between the adjacent other second support members 620 or the distal end portions 619A of the first support members 619 in at least one location in the circumferential direction is a size necessary for treatment. If there is, it is not particularly limited. For example, four or more second support members 620 may be provided.
For example, in the seventh embodiment and each modified example, the second support member 620 is a solid rod. However, the shape of the second support member 620 is not particularly limited as long as it has the necessary flexibility for the distal end fixing portions 603, 603A, 603B. For example, the second support member 620 may be a hollow tube closed at both ends. For example, the second support member 620 may be formed of a radially flat flat plate or a plate having a curved surface convex radially outward.
For example, in the seventh embodiment and each modified example, the airflow tube 609 includes two channels, but the airflow tube 609 may be formed of two independent tubes. In this case, the connectors provided at the ends of the respective tubes are detachably connected to the first connecting tube and the second connecting tube of the connector 605c.

In the seventh embodiment and the twenty-first modification, when the distal end portion 12 of the endoscope 11 is arranged between the first balloon 622 and the second balloon 623 in the vicinity of the treatment site Ts, the endoscope 11 is fixed and the overtube 601 is pushed distally. However, the relative movement between the endoscope 11 and the overtube 601 is not limited to pushing the overtube 601 . For example, the position of the overtube 601 may be fixed and the endoscope 11 may be pulled proximally, or the endoscope 11 may be pulled while pushing the overtube 601 .

In the seventh embodiment, an example in which the endoscope 11 is inserted to the vicinity of the treatment site Ts in advance will be described. An example of inserting up to is explained. However, these operations may be appropriately combined according to the lengths of the endoscope 11 and the overtube 601.
For example, the endoscope 11 may be inserted into the lumen to a position remote from the treatment site Ts on the proximal side, and then the overtube 601 may be inserted near the distal end portion 12 along the endoscope 11. good.
Thereafter, the overtube 601 may be inserted near the treatment site Ts after inserting only the endoscope 11 to the treatment site Ts, or the overtube 601 may be inserted near the treatment site Ts together with the endoscope 11. You may

The first balloon 622B in the 23rd modification may be used instead of the first balloon 622 in the 7th embodiment and the 22nd modification. In this case, the first cylindrical surface portion 622g of the first balloon 622B is fixed to the outer peripheral surface 621b of the tube member 621. As shown in FIG. In this case, the axial length of the pipe member 621 may be the same as the axial length of the first cylindrical surface portion 622g. Thereby, the axial length of the first fixing portion 617 can be shortened.

The first balloon 622B in the 23rd modification may be used instead of the second balloon 623 in the 7th embodiment, the 22nd modification, and the 23rd modification. However, in this case, the opening 602f is formed in the first cylindrical surface portion 622g. The first cylindrical surface portion 622g of such a first balloon 622B is fixed to the outer peripheral surface 2d of the main tube 602 with the opening 602f and the opening 2f communicating with each other.

In the 22nd modification, an example has been described in which the circumferential intervals of the tip portion 619A of the first support member 619 and each of the second support members 620 correspond to two types of central angles β1 and β2. However, if the intervals in the circumferential direction between the distal end portion 619A of the first support member 619 and the second support members 620 are unequal, they are not limited to this.

As described above, the first balloons 622 and 622B are examples of distal balloons that are arranged distally of the tube body and that can expand and contract in the radial direction.
The second balloon 623 is an example of a fixing balloon that is provided on the outer peripheral surface of the distal end of the tube body and that can expand outward from the outer peripheral surface and contract toward the outer peripheral surface.
A distal portion 619A of a first support member 619 and a second support member 620 are disposed about the respective peripheries of the anchoring balloon and the distal balloon and extend between the anchoring balloon and the distal balloon to provide a lumen. 4 is an example of a plurality of support members capable of supporting the inner wall of the .
The first support member 619 has a channel communicating with the interior of the distal balloon. The first support member 619 is an example of a support member that forms an air delivery tube that forms a flow path for delivering gas to the distal balloon.

[Eighth Embodiment]
An endoscope overtube according to an eighth embodiment of the present invention will be described.
FIG. 119 is a schematic perspective view showing an example of an endoscope overtube according to the eighth embodiment of the present invention. 120 is a cross-sectional view taken along line F120-F120 in FIG. 119. FIG. 122 is a cross-sectional view taken along line F122-F122 in FIG. 120. FIG. 123 is a cross-sectional view taken along line F123-F123 in FIG. 121. FIG.

An overtube 701 shown in FIG. 119 is an example of an endoscope overtube according to this embodiment.
The overtube 701 has a distal end fixing portion 703, a first support member 619, a grip portion 605, an airflow tube 609, and an air supply device 610, respectively, of the overtube 601 according to the seventh embodiment. It has a grip portion 705 , a first connection tube 708 D, a second connection tube 708 P, an airflow tube 9 and an air supply device 710 . The overtube 701 further has a channel switch 711 .
However, FIGS. 119 to 121 show the shape of the distal end fixing portion 703 in the expanded state, as in the sixth embodiment.
In the following, the points different from the seventh embodiment will be mainly described.

As shown in FIG. 120, the distal end fixing portion 703 in this embodiment includes a first supporting member 719, a It has a second support member 720 and a second fixing portion 718 . The tip fixation part 703 has a first fixation part 617 similar to the tip fixation part 603 .

The first support member 719 has a front end portion 719A and a rear end portion 719B (air supply tube, operating rod) similar to the front end portion 619A and rear end portion 619B of the first support member 619 .
However, the distal end portion 719A of the first support member 719 is not joined to the second balloon 623, and the rearward end portion 619B passes through the inside of the grip portion 705 to be described later to reach the slider 715 (see FIG. 122) to be described later. held.
As will be described later, the first support member 719 is also used as an operating rod for advancing and retreating the first fixing part 617 in the axial direction. It has enough rigidity to prevent buckling deformation even if it is received.
As shown in FIG. 120, the distal end region 719a of the distal end portion 719A of the first support member 719 is the same as the distal end portion 619A of the first support member 619 in the seventh embodiment. It is fixed to the portion 622c. However, unlike first support member 619 , first support member 719 is not fixed to second balloon 623 .

The second support member 720 is the same as the second support member 620 except that a retaining portion 720b is formed at the rear end. The retainer portion 720b is a protrusion that protrudes from the outer shape of the second support member 720 in a direction orthogonal to the longitudinal direction of the second support member 720. As shown in FIG.
The second support member 720 has a rod shape with a uniform cross-sectional shape on the distal end side of the retaining portion 720b. In the example shown in FIG. 121, the second support member 720 on the distal end side of the retaining portion 720b has a cylindrical shape.
As shown in FIG. 120, the distal end portion 720a of the second support member 720 is fixed to the second cylindrical portion 622c of the first balloon 622 in the same manner as the distal end portion of the second support member 620 in the seventh embodiment. ing.
Like the second support member 620, the second support member 720 is provided in three positions along with the distal end portion 719A of the first support member 719, and equally divides the second cylindrical portion 622c in the enlarged diameter state into four in the circumferential direction. there is

The second fixed part 718 has a second balloon 623 fixed to the distal end of the main tube 602 and a guide tube 718a, as in the seventh embodiment.
The guide tube 718a has an insertion hole 718b extending longitudinally through the center.
The inner diameter of the insertion hole 718b has such a size that the retainer portion 720b cannot be inserted, and the first support member 719 and the second support member 720 excluding the retainer portion 720b can be inserted.
The shape of the inner peripheral surface forming the insertion hole 718b is not particularly limited as long as the second support member 720 excluding the first support member 719 and the retaining portion 720b can be smoothly inserted.
In the example shown in FIG. 121, the inner peripheral surface forming the insertion hole 718b is a cylindrical surface corresponding to the cylindrical surface of the outer peripheral portion of the second support member 720 excluding the first support member 719 and the retaining portion 720b. is.

Four guide tubes 718a are provided at positions that equally divide the second cylindrical portion 623c of the second balloon 623 into four in the circumferential direction. Each guide tube 718a is fixed to the outer peripheral portion of the second cylindrical portion 623c in the same manner as the first support member 619 and each second support member 620 in the seventh embodiment.
A distal end portion 719A of a first support member 719 and three second support members 720 are axially movably inserted through each guide tube 718a.
The retaining portion 720b of each second support member 720 protrudes further to the rear end side than the guide tube 718a, thereby preventing each second support member 720 from coming off to the front end side.

With such a configuration, the first fixing portion 617 of the distal end fixing portion 703 is axially movable between the maximum advanced position indicated by the solid line in FIG. 120 and the retracted position indicated by the two-dot chain line in FIG. be.
Here, the maximum advanced position is the position where each retainer portion 720b is engaged with the rear end of each guide tube 718a and is farthest from the second fixing portion 718 toward the tip side. The retracted position is a position where the rear end 621c of the pipe member 621 and the front end 602g of the main tube 602 are in contact with each other.
The distance in the axial direction between the rear end 621c of the pipe member 621 and the front end 602g of the main tube 602 at the most advanced position is the same distance Lf as in the seventh embodiment.

As shown in FIG. 122, the grip section 705 has a distal balloon movement mechanism 712 instead of the connector 605c in the grip section 605. As shown in FIG.
The distal balloon movement mechanism 712 axially moves the entire first fixing portion 617 including the first balloon 622 by moving the first support member 619 in the axial direction.
The configuration of the distal balloon movement mechanism 712 is not particularly limited as long as it can hold the rear end portion of the rear end portion 619B of the first support member 619 and move the first support member 619 in the axial direction.
In the example shown in FIG. 122 , the distal balloon movement mechanism 712 has a slide guide section 713 , a slider 715 and a slide operation section 714 .

The slide guide portion 713 has a substantially rectangular bar shape extending obliquely outward in the radial direction toward the rear end side from the outer peripheral surface of the grip portion 605 on the rear end side (right side in the figure) of the stopper 5b.
Inside the slide guide portion 713, an insertion hole 713a and a guide groove 713b are aligned in this order and pass through from the front end side (left side in the drawing) surface of the stopper 5b toward the rear end of the slide guide portion 713. there is

Through the insertion hole 713 a , the first support member 719 extending from the opening 602 h opened at the rear end of the main tube 602 is inserted in the extending direction of the slide guide portion 713 . In the example shown in FIG. 122, the cross-sectional shape of the insertion hole 713a orthogonal to the extending direction is circular with a diameter larger than the outer diameter of the first support member 719. In the example shown in FIG.
The insertion hole 713a passes through the tubular portion 5a and communicates with the opening 602h of the main tube 602 fixed to the tubular portion 5a.

As shown in FIG. 123, the guide groove 713b has a substantially square groove shape that guides the rectangular parallelepiped slider 715 in the extending direction. The cross-sectional area of the guide groove 713b in the cross section perpendicular to the extending direction of the slide guide portion 713 is larger than the cross-sectional area of the insertion hole 713a in the same cross section. As shown in FIG. 122, the insertion hole 713a opens inside a tip surface 713f formed on the tip side of the guide groove 713b.
The tip surface 713f locks the tip of the slider 715 when the slider 715 moves to the tip end side. The tip surface 713f defines the movement position of the slider 715 on the most tip side.
A rear end surface 713g is formed at the rear end portion of the slide guide portion 713 to prevent the slider 715 from coming off at the rear end side. The rear end surface 713g defines the movement limit of the slider 715 on the rearmost end side. However, since the first fixing portion 617 to which the first support member 719 is connected cannot be retracted to the rear end side of the retracted position, the rear end face 713g may be omitted. In this case, the guide groove 713 b opens at the rear end of the slide guide portion 713 .

As shown in FIG. 123, a slit 713c is formed in a side wall 713e, which is one side wall of the slide guide portion 713 surrounding the guide groove 713b.
The side wall 713e may be a side wall in any direction as long as it can be operated by the operator. In the example shown in FIG. 122, the side wall 713e extends along the slope of the slide guide portion 713 and is the side wall farther from the tubular portion 5a in the radial direction.
The slit 713c penetrates in the thickness direction of the side wall 713e and extends in the extending direction of the slide guide portion 713 . The length of the slit 713c is longer than or equal to Lf.
As shown in FIG. 122, the opening width of the slit 713c in the lateral direction (horizontal direction in the drawing) is narrower than the groove width of the guide groove 713b in the same direction.
With such a configuration, the guide groove 713b has a C-shaped groove shape with the slit 713c opening at the side wall 713e.

As shown in FIG. 123, the slide guide portion 713 extends in the extension direction of the slide guide portion 713 next to the guide groove 713b. The pipeline 713 d penetrates through the slide guide portion 713 .
Although not shown, the conduit 713d passes through the tubular portion 5a and communicates with the second lumen 2e of the main tube 602 fixed to the tubular portion 5a.
The conduit 713 d extends to the rear end of the slide guide portion 713 . A rear end portion of the slide guide portion 713 is provided with a first luer connector 5c similar to that of the first embodiment. The first luer connector 5c in this embodiment communicates with the interior of the conduit 713d.

The slide guide part 713 may be made of the same material as the tubular part 5a and the stopper 5b. For example, the slide guide portion 713, the tubular portion 5a, and the stopper 5b may be formed of resin moldings.

As shown in FIGS. 122 and 123, the slider 715 is fitted into the guide groove 713b so as to be slidable in the extending direction of the slide guide portion 713. As shown in FIGS. In the illustrated example, the outer shape of the slider 715 is a cuboid.
As shown in FIG. 123 , inside the slider 715 , a holding hole 715 b having a diameter larger than the outer diameter of the first support member 719 penetrates in the extending direction of the slide guide portion 713 . A rear end portion 719B of the first support member 719 is inserted through the holding hole 715b. The rear end portion 719B is fixed to the slider 715 inside the holding hole 715b. A fixing method of the rear end portion 719B is not particularly limited. In the example shown in FIG. 123, the rear end portion 719B is fixed to the holding hole 715b with an adhesive 716 interposed.

On the side surface of the slider 715 facing the slit 713c, a female threaded portion 715c is formed at a portion overlapping the inside of the slit 713c when viewed from the outside.

The material of the slider 715 is not particularly limited as long as it can slide along the guide groove 713b. For example, the material of the slider 715 may be metal or resin.

The slide operation portion 714 has a knob portion 714a, a fixing portion 714b, and a male screw portion 714c.
The knob portion 714a has a size that can be gripped and rotated by the operator. For example, the knob portion 714a is a disc.
The fixing portion 714b is a stepped portion that straddles the slit 713c and engages with the edge portion of the slit 713c. For example, the fixing portion 714b is cylindrical and provided coaxially with the knob portion 714a. The outer diameter of the fixed portion 714b is larger than the width of the slit 713c in the lateral direction.
The male threaded portion 714 c is screwed with the female threaded portion 715 c of the slider 715 . The male screw portion 714c protrudes from the fixed portion 714b so as to be coaxial with the knob portion 714a. The length of the male screw portion 714c is longer than the thickness of the side wall 713e.

The slide operation portion 714 is connected to the slider 715 by threading the male screw portion 714c into the female screw portion 715c through the slit 713c.

The operation of the distal balloon movement mechanism 712 will be described.
When the operator rotates the slide operation portion 714 in the direction in which the male threaded portion 714c is screwed, the fixed portion 714b contacts the surface of the side wall 713e, and the side wall 713e at the edge of the slit 713c moves between the slider 715 and the fixed portion 714b. sandwiched by Thereby, the slider 715 and the slide operation portion 714 are fixed to the slide guide portion 713 .
When the operator rotates the slide operation portion 714 in the direction opposite to the screwing direction of the male screw portion 714c, the holding of the side wall 713e between the fixing portion 714b and the slider 715 is released. Accordingly, the operator can slide the slider 715 by moving the knob portion 714a along the slit 713c.
At this time, the first support member 719 fixed to the slider 715 on the rear end side of the rear end portion 719B also moves in the same direction. The first fixing portion 617 fixed to the distal end portion 719A of the first support member 719 can be similarly moved when the first balloon 622 is expanded to the fixed expanded state and is not fixed to the lumen. .
Thus, according to this embodiment, by operating the slide operation part 714, the position of the first fixing part 617 in the lumen can be moved in the axial direction without moving the main tube 602. . The position after movement can be fixed until the operator loosens the slide operation part 714 by screwing the slide operation part 714 .
Furthermore, by changing the movement position of the slide operation part 714, the distance between the first fixing part 617 and the tip of the main tube 602 can also be changed.
In the moving operation of the first fixing portion 617 , the first support member 719 functions as an operating rod that transmits the operating force to the first fixing portion 617 .

As shown in FIG. 119, the first connection tube 708D is located between a first end 708a, which is a connector detachably connected to the rear end of the first support member 719, and a second end 708b on the rear end side. Then, a flow path is formed for circulating air.
The second end portion 708b is provided with an appropriate connector that is detachably connected to a channel switching device 711, which will be described later. The first connection tube 708D is detachably connected to the channel switch 711 by a connector provided at the second end 708b.

The second connection tube 708P is provided between a first end 708c, which is a connector detachably connected to the first luer connector 5c in the distal balloon moving mechanism 712, and a second end 708d on the rear end side. to form a flow path for circulating.
The first end 708c is provided with a luer connector that can be attached to and detached from the first luer connector 5c. The second end portion 708d is provided with an appropriate connector that is detachably connected to the channel switching device 711 . The second connection tube 708P is detachably connected to the channel switching device 711 at the second end 708d.

The flow path switch 711 divides the flow path formed by the airflow tube 9 similar to that of the first embodiment into the flow path formed by the first connection tube 708D and the flow path formed by the second connection tube 708P. and selectively switch to .
The channel switching device 711 incorporates a channel switching valve, and has a switching operation part 711a for operating the channel switching valve. The switching operation unit 711a can be switched by the operator.

The air supply device 710 is the same as the air supply device 10 in the first embodiment except that the airflow tube 9 of the air supply device 710 is connected to the flow path switch 711 .
The air supply device 710 may be an electric pump or a manual pump as in the first embodiment. In the case of a manual pump, any air supply device including the manual air supply mechanism 211 in each of the embodiments and modifications described above may be used as the air supply device 710 .

Next, a method of using the overtube 701 will be described, focusing on points different from the seventh embodiment. As a treatment, an example of performing endoscopic full-thickness resection of the large intestine C will be described as in the seventh embodiment.
124 to 128 are cross-sectional views showing an example of how to use the endoscope overtube according to the eighth embodiment of the present invention.

First, the overtube 701 is prepared.
As shown in FIG. 124, the distal end fixing portion 703 of the overtube 701 to be prepared is reduced in diameter like the distal end fixing portion 603 of the overtube 601 . Furthermore, in the present embodiment, the first support member 719 is pulled rearward, so that the first fixing portion 617 is retreated rearward from the maximum advanced position. The distance between the trailing end 621c and the leading end 602g in the axial direction is Li. The distance Li is 0 or more and less than Lf. The size of Li is determined in consideration of the insertion resistance at the bent or curved portion of the endoscope 11 .
For example, when Li is 0, the first fixed part 617 is in the retracted position. In this case, the pipe member 621 and the tip of the main tube 602 are in contact with each other to form an integral cylinder. Therefore, depending on the rigidity of the tube member 621 and the main tube 602 , they can pass through the bend or curve of the endoscope 11 by deforming each. The lower the rigidity of the pipe member 621 and the main tube 602, the lower the insertion resistance.
On the other hand, when Li is greater than 0, the tubular member 621 can rotate within the range of the gap between the rear end 621c and the front end 602g. This reduces insertion resistance.
However, as Li approaches Lf, the first support member 719 and the second support member 720 between the first fixing portion 617 and the second fixing portion 718 tend to bend. If the first support member 719 and the second support member 720 bend along the side surface of the endoscope 11, no particular problem occurs. However, when the radius of curvature of the endoscope 11 is small, or when the first fixing portion 617 is caught on the inner wall of the lumen, the external force acting on the first support member 719 or the second support member 720 increases, The first support member 719 or the second support member 720 may bend.
The shorter Li is, the less likely the first support member 719 and the second support member 720 are to bend.

Thereafter, the operator inserts the distal end of the endoscope 11 inside the airtight valve unit 6 of the overtube 701 as in the seventh embodiment, as indicated by the two-dot chain line. can extend from the tubular member 621 .
In addition, in this embodiment, the airtight valve unit 6 may not be provided.

Thereafter, the operator places the overtube 701 outside the patient's body, and inserts the insertion portion of the endoscope 11 projecting from the overtube 701 into the large intestine C from the anus in the same manner as in the seventh embodiment. Then, the distal end portion 12 of the endoscope 11 is moved to a position where the treatment site Ts can be seen (see FIG. 125).

Thereafter, as shown in FIG. 125, the operator inserts the overtube 701 into the large intestine C from the anus along the insertion portion of the endoscope 11 in the same manner as in the seventh embodiment.
As shown in FIG. 126 , the operator inserts the overtube 701 until the distal end fixing portion 703 is positioned near the rear end of the distal end portion 12 of the endoscope 11 .
After that, the operator operates the tip side balloon movement mechanism 712 to advance the first support member 719 to the distal side. As a result, as shown in FIG. 127, the first fixing portion 617 is pushed further to the distal side than the distal end portion 12 .

The operation of pushing out the first fixing portion 617 is performed by the operator only by sliding the unscrewed slide operation portion 714 in the extending direction of the slide guide portion 713 . The operator does not need to move both the grip portion 705 of the overtube 701, the main tube 602 and the endoscope 11 outside the body during the sliding operation.
For example, when the overtube 601 is pushed in to move the first fixing portion 617 distally as in the seventh embodiment, the overtube 601 slides on the intestinal wall Cw. Therefore, the operator needs to operate against the sliding resistance between the overtube 601 and the endoscope 11 and the sliding friction between the overtube 601 and the intestinal wall Cw. In particular, sliding between the overtube 601 and the intestinal wall Cw may be a burden on the patient.
However, in this embodiment, the first fixing portion 617 in a reduced diameter state is pushed out without the main tube 602 being pushed in. As shown in FIG. For this reason, the resistance received by the operator is the sliding resistance between the first support member 719 having a small diameter and the insertion lumen 602e, so the resistance received by the operator is reduced. This makes it easier for the operator to guide the first fixing portion 617 to the fixing position. Furthermore, since the first support member 719 does not come into contact with the intestinal wall Cw when pushed distally, no load is applied to the patient.

The operator moves the first fixing part 617 to the maximum advanced position. As a result, the distal end portion 12 is sandwiched between the first fixing portion 617 and the second fixing portion 718 in the axial direction of the large intestine C. As shown in FIG.

After that, the operator confirms whether either the first support member 719 or the second support member 720 is positioned to straddle the treatment site Ts in the same manner as in the seventh embodiment. As in the seventh embodiment, the operator rotates the overtube 701 outside the body in the circumferential direction as necessary to adjust the positions of the distal end portion 719A of the first support member 719 and the second support member 720. Shift in the circumferential direction.
If necessary, after the circumferential position adjustment of the distal end fixing portion 703 is completed, the operator operates the air supply device 710 to separate the first balloon 622 and the second balloon 622 in the same manner as in the seventh embodiment. 623 is inflated to the enlarged diameter state when fixed.
However, in the present embodiment, since the air supply device 710 has a single channel, one of the first balloon 622 and the second balloon 623 is set in a diameter expanded state when fixed, and then the first balloon 622 and the second balloon 623 are expanded. The other of the balloons 623 is set in an enlarged diameter state when fixed.
The overtube 701 may be provided with an air supply device capable of independently supplying air to both the first connection tube 708D and the second connection tube 708P instead of the air supply device 710 . In this case, the first balloon 622 and the second balloon 623 can be brought into the enlarged diameter state at the time of fixation at the same time.

As shown in FIG. 128, when the first balloon 622 and the second balloon 623 are respectively expanded in diameter when fixed, the distal end fixing part 703 is fixed inside the intestinal wall Cw. The first support member 719 and each second support member 720 are pressed against the inner surface of the intestinal wall Cw and support the intestinal wall Cw from the inside.
As a result, a space Sf in which the endoscope 11 can move is formed between the first balloon 622 and the second balloon 623, as in the seventh embodiment.

After this, the operator can perform endoscopic full-thickness resection within the space Sf in the same manner as in the seventh embodiment. At that time, even if a through hole is formed in the intestinal wall Cw, the intestinal wall Cw is stretched between the first balloon 622 and the second balloon 623, and the distal end portion 719A of the first support member 719 and the second balloons 623 and 719A. Since it is supported from the inside by the support member 720, the surgical field is secured as in the seventh embodiment.

After completing all necessary procedures for endoscopic full-thickness resection, the operator operates the air supply device 710 and the flow path switch 711 to suck out the air in the first balloon 622 and the second balloon 623 . As a result, the diameters of the first balloon 622 and the second balloon 623 are reduced.
After that, the operator pulls out the endoscope 11 and the overtube 701 from the anus.
Endoscopic full-thickness resection using the overtube 701 is thus completed.

The method of using the overtube 701 has been described above with an example of endoscopic full-thickness resection. However, if it is an endoscopic treatment that can be performed using the space Sf as an operating field, the overtube 701 is used for treatments other than endoscopic full-thickness resection, like the overtube 601 of the seventh embodiment. may

The overtube 701 according to the present embodiment is configured in the same manner as the overtube 601 except that it has a distal end fixing portion 703 instead of the distal end fixing portion 603, so it is similar to the seventh embodiment. have an effect. Therefore, according to the present embodiment, as in the seventh embodiment, it is possible to provide an endoscope overtube that reduces the burden on a patient and allows smooth operation of the endoscope.
Particularly in this embodiment, the distance between the first fixing part 617 and the second fixing part 618 can be changed by the operator's operation. As a result, the overtube 701 can be inserted into the lumen while the distal end fixing portion 703 is compact, thereby further reducing the burden on the patient.
Furthermore, the operator can easily guide the first fixing part 617 to the fixing position without imposing a load on the patient.

The eighth embodiment described above may be implemented with various modifications.
For example, the guide tube 718 a is not limited to a mode in which a separate member is fixed to the second balloon 623 . For example, when molding the second balloon 623, a lumen similar to the guide tube 718a may be formed on the outer circumference of the second cylindrical portion 623c.
For example, the guide tube 718a is not limited to an axially long tubular member, and may be formed of a ring having a short axial length. In this case, a plurality of rings may be provided spaced apart in the axial direction.

In the eighth embodiment described above, the example in which the rear end portion 719B of the first support member 719 also serves as the operation rod for advancing and retracting the first fixing portion 617 has been described. However, the operating rod may have a configuration in which the second support member 720 is extended to the rear end. In this case, the main tube 602 is provided with an insertion lumen 602e through which the first support member 719 is inserted, and an insertion lumen through which the extended second support member is inserted.
The number of operating rods is not limited to one. The greater the number of operating rods, the easier the movement of the first fixing portion 617 becomes.

In the eighth embodiment described above, an example in which the operating rod is inserted through the insertion lumen 602e of the main tube 602 has been described. However, the operating rod may pass through a sheath fixed to the outer circumference of the overtube 701 . In this case, the insertion lumen 602e can be omitted.

As described above, the distal end portion 719A of the first support member 719 and the second support member 720 are arranged on the respective outer peripheries of the fixation balloon and the distal balloon, and between the fixation balloon and the distal balloon. Figure 10 is an example of a plurality of support members that can extend into and support the inner wall of a lumen;
The first support member 719 has a channel communicating with the interior of the distal balloon. The first support member 719 is an example of a support member that forms an air delivery tube that forms a flow path for delivering gas to the distal balloon.

A rear end portion 719B of the first support member 719 extends along the tube main body to the rear end portion of the tube main body, and is provided so as to be interlockable with one of the plurality of support members. It is an example of an operating rod that drives the part in the axial direction of the tube body. The operation rod in this embodiment is an example that is interlocked with the support member by being formed by the rear end portion of the support member.
The distal side balloon moving mechanism 712 is an example of a distal side balloon moving mechanism that is arranged on the rear end side of the rear end portion of the tube body and moves the operating rod along the axial direction.

Although preferred embodiments and modifications of the present invention have been described above, the present invention is not limited to such embodiments and modifications. Configuration additions, omissions, substitutions, and other changes are possible without departing from the scope of the present invention.
Moreover, the present invention is not limited by the foregoing description, but only by the scope of the appended claims.

According to each of the above-described embodiments and modifications, it is possible to provide an endoscope overtube that reduces the burden on the patient and allows smooth operation of the endoscope.

1, 101, 201, 301, 401, 501, 601, 701 Overtube (overtube for endoscope)
2, 102, 102A, 602 Main tube (tube body)
2a Tube wall (constant thickness part)
2b Thick portion 2c First lumen (main lumen)
2d outer peripheral surface 2e second lumen (air supply lumen)
2f opening 3 fixation balloons 6, 506, 506A, 506B airtight valve units 9, 609 airflow tube (air supply tube)
10, 110, 210, 210A, 210B, 210C, 210D, 210E, 210F, 210G, 310, 410, 410A, 610, 710 Air supply devices 11, 30 Endoscopes 21, 521 Cylindrical frame portion (tubular portion)
21a inner peripheral surface 22, 522 airtight balloons 22b, 522b intermediate portion 102g third lumen (dummy lumen)
111a pump (manual pump)
112 pressure gauge 113 relief valve 211 manual air supply mechanism 211a pump (manual pump)
211d first connection part (pump side connector, first connector)
211e Second connection part (pump side connector, second connector)
211j air supply pipe 211k intake pipe 212, 212A, 212B, 212C, 212D, 412 body portion 212a connection pipe (body side connector)
213 relief valve 215 grip (holding portion)
217, 217A, 217B pressure adjustment units 219, 219E, 219F, 219G, 319, 319A, 319B, 319C, 319D, 319E, 319F, 319H, 319J, 319K, 319L, PI pressure indicator 219D pressure display units 220, 320E, 320F, 320H, 320J case (enclosure)
220b side part (moving pipeline)
220h Opening 221a Display window 221b First scale line (reference scale)
221c second scale line (reference scale)
221D display window forming member 222 fixed frame (holding member)
223, 323, 323A, 323B, 323E, 323F, 323H, 323K, 323L collar (moving member)
223a outer cylindrical portion (tubular portion)
223b, 323b locking plate (elastic member supporting portion)
223c tip edge portion 224 coil spring (elastic member)
225, 225E, 225F, 325B, 325D, 325K, 325L Airtight member (sealing member, pressing member)
225a boss portion (second fixing portion)
225c bottom plate portion (second fixing portion)
225d, 226 bellows tube portion 225f sealing portion (first fixing portion)
225n thick portion 225t thin portion 230 body case (housing)
323d, 323h, 323v, 325t Inclined surfaces 323f, 322m, 325r Plural protrusions (elastic member support portions)
323q stepped portion (elastic member supporting portion)
323t presser claw (elastic member support)
325f Engagement projections 417, 417A Limiter 417a Side plate portion (locking member)
417b locking projection (locking member)
417f first side plate portion (locking member)
417g second side plate portion (locking member)
417h fastener (fixing member)
521b connection port (gas supply pipe)
531, 531A Variable volume part 533 Movable member 534 Probe 534a Sliding contact part (tip part)
535 spring (biasing member)
602e insertion lumens 603, 703 distal end fixing portions 619, 719 first support member (plurality of support members)
619A, 719A Front end 619B Rear end (air supply tube)
719B rear end (air supply tube, operation rod)
619a Air supply lumens 620, 720 Second support member (plurality of support members)
622, 622B first balloon (tip side balloon)
623 second balloon (fixation balloon)
712 Distal side balloon movement mechanism AC, AG, Ah, Ai, AP, O ₂₂₀ , Oc Central axis Av Axis C Large intestine On Narrow opening Ow Wide opening P1, P6 First pipe P2 Constriction P3, P8 Second pipe Paths P4, P7 Expanded diameter portions R1, R1A First regions R2, R2A Second regions Tv Thickness change portions

Claims (15)

1. An endoscope overtube,
   a tube body having a main lumen through which an endoscope is inserted and an air supply lumen through which gas flows;
   a fixing balloon provided on the outer peripheral surface of the distal end portion of the tube body, expandable outward from the outer peripheral surface and contractible toward the outer peripheral surface;
   an insufflation device that delivers the gas to the insufflation lumen;
   A gap between an endoscope having a tubular portion communicating with the main lumen at the rear end portion of the tube body, and inserted into the main lumen through the tubular portion, and the inner peripheral surface of the tubular portion. a sealing airtight valve unit;
   comprising
   Overtube for endoscope.
2. The air supply device is
   a manual pump for delivering the gas;
   a first conduit through which the gas sent from the manual pump flows;
   a constricted portion connected to the first pipeline and having a flow channel cross-sectional area smaller than the flow channel cross-sectional area of the first pipeline;
   a second conduit having a flow channel cross-sectional area larger than the flow channel cross-sectional area of the narrowed portion and allowing the gas flowing through the narrowed portion to flow toward the fixation balloon;
   a relief valve provided in the second pipeline for exhausting the gas from the second pipeline when the pressure in the second pipeline exceeds a certain value;
   comprising a
   The endoscope overtube according to claim 1.
3. The inner diameters of the first pipeline and the second pipeline are D [mm],
   The narrowed portion has an inner diameter of d [mm] and a length of L ₁ [mm],
   When the length of the second pipeline is L ₂ [mm], the following formula (3e) is satisfied,
   The endoscope overtube according to claim 2.
   

   
4. The air supply device is
   a manual pump for delivering the gas;
   a first conduit through which the gas sent from the manual pump flows;
   an enlarged diameter portion connected to the first pipeline and having a flow channel cross-sectional area larger than the flow channel cross-sectional area of the first pipeline;
   a relief valve provided in the enlarged diameter portion for exhausting the gas from the enlarged diameter portion when pressure in the enlarged diameter portion exceeds a predetermined value;
   a second pipeline having a flow channel cross-sectional area smaller than the flow channel cross-sectional area of the diameter-enlarged portion and allowing the gas flowing through the diameter-enlarged portion to flow toward the fixation balloon;
   comprising
   The endoscope overtube according to claim 1.
5. The inner diameter of the first conduit is D,
   When the volume of the expanded diameter portion is V and the maximum volume of the gas that can be supplied by one operation of the manual pump is _QP , the following formula (3j) is satisfied.
   The endoscope overtube according to claim 4.
   

   
6. The air supply device is
   a manual pump for delivering the gas;
   a first conduit through which the gas sent from the manual pump flows;
   a pressure indicator that is connected to the first conduit, has a channel that has a channel cross-sectional area that is larger than the channel cross-sectional area of the first conduit, and displays the pressure of the first conduit;
   a constricted portion connected to the first pipeline and having a flow channel cross-sectional area smaller than the flow channel cross-sectional area of the first pipeline;
   a second conduit having a flow channel cross-sectional area larger than the flow channel cross-sectional area of the narrowed portion and allowing the gas flowing through the narrowed portion to flow toward the fixation balloon;
   a relief valve provided in the second pipeline for exhausting the gas from the second pipeline when the pressure in the second pipeline exceeds a certain value;
   comprising a
   The endoscope overtube according to claim 1.
7. The pressure indicator is
   a housing at least partially provided with a display window through which the inside can be seen;
   a moving member that moves within the housing according to the pressure inside the housing and whose movement position is observable from the display window;
   A reference scale indicating the pressure according to the position of the moving member is formed on the display window or around the display window.
   have
   The endoscope overtube according to claim 6.
8. The housing has a moving conduit in which the moving member moves,
   The moving member has a tubular portion that moves along the central axis of the moving conduit,
   the tubular portion of the moving member moves in a posture inclined in a certain direction with respect to the central axis of the moving pipe;
   The display window is formed at a position where an end of the tubular portion of the moving member that is closer to the display window can be seen due to the inclination of the tubular portion of the moving member.
   The endoscope overtube according to claim 7.
9. The pressure indicator is
   an elastic member that biases the moving member against the pressure acting on the moving member and regulates the moving position of the moving member according to the pressure;
   a pressing member disposed opposite to the moving member in the moving direction of the moving member and pressing an end of the elastic member opposite to the moving member;
   One or both of the moving member and the pressing member are arranged on the inclined surface inclined in the certain direction with respect to the central axis when the tubular portion is arranged coaxially with the central axis. comprising an elastic member support that supports the member;
   The endoscope overtube according to claim 8.
10. The pressure indicator is
    further comprising a sealing member that hermetically seals an opening formed at an end of the housing in the moving direction of the moving member;
    The sealing member is
    a first fixing portion airtightly fixed to the end;
    a bellows tube portion extending from the first fixing portion toward the moving member and having a bellows shape on the side surface thereof which can be expanded and contracted in the moving direction;
    a second fixing portion that closes the end of the bellows tube portion in the extending direction and is fixed to the moving member;
    has
    The bellows tube portion
    an inclined surface portion forming a part of a side surface of the bellows tube portion and arranged in an inverted V shape tapering radially outward in a cross section including the central axis of the bellows tube portion;
    a thick portion which is formed to be thicker than the average thickness of the inclined surface portion and airtightly closes the outer peripheral portion of the inclined surface portions forming the inverted V shape;
    has a
    The endoscope overtube according to claim 7.
11. In the thick portion,
    The first width of the bellows tube portion in the axial direction along the central axis is three times or more the average wall thickness and 2/2 of the pitch of the bellows shape in the natural state where the bellows tube portion is not deformed by an external force. is 3 or less,
    A second width of the bellows tube portion in a radial direction orthogonal to the central axis is three times or more the average thickness,
    The endoscope overtube according to claim 10.
12. The average thickness is 0.3 mm or more and 0.7 mm or less,
    The second width is 3.1 mm or less,
    The endoscope overtube according to claim 11.
13. The air supply device is
    a manual pump for delivering the gas;
    a first conduit through which the gas sent from the manual pump flows;
    a main body to which the manual pump is connected,
    The main body is
    a pressure indicator that is connected to the first conduit, has a channel that has a channel cross-sectional area that is larger than the channel cross-sectional area of the first conduit, and displays the pressure of the first conduit;
    a gripping portion extending in a direction intersecting the central axis of the manual pump connected to the main body and arranged to form an inverted V shape with the central axis;
    with
    The pressure indicator is
    a housing at least partially provided with a display window through which the inside can be seen;
    a moving member that moves within the housing according to the pressure inside the housing and whose movement position is observable through the display window;
    has
    a reference scale indicating a pressure corresponding to the position of the moving member is formed on the display window or around the display window;
    the central axis of the manual pump and the extending direction of the gripping portion form an acute angle with respect to the moving direction of the moving member;
    the display window is positioned between the grip position of the manual pump and the grip in the direction of movement;
    The endoscope overtube according to claim 1.
14. The air supply device is
    a manual pump for delivering the gas;
    a main body to which the manual pump is connected;
    a body-side connector that protrudes from the body and detachably connects the manual pump in a first direction;
    with
    The manual pump is
    a pump-side connector that advances and retreats in the first direction, is airtightly connected to the main body-side connector when advancing, and causes the gas to leak when retreating;
    The main body is
    a limiter that regulates the retracted position of the pump-side connector by engaging with the pump-side connector when retracting the pump-side connector and prevents the pump-side connector from coming off;
    The endoscope overtube according to claim 1.
15. The manual pump includes an air pipe that delivers gas,
    an intake pipe for sucking gas;
    has
    The pump-side connector is
    a first connector that detachably connects the air pipe to the body-side connector;
    a second connector that detachably connects the intake pipe to the body-side connector;
    has
    The limiter is
    a locking member movable between a locking position where the pump-side connector can be locked and a removal position where the pump-side connector can be removed from the body-side connector;
    a fixing member capable of fixing the locking member to one of the locking position and the removal position;
    has a
    The endoscope overtube according to claim 14.

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