WO2019044186A1

WO2019044186A1 - Endoscope insertion part

Info

Publication number: WO2019044186A1
Application number: PCT/JP2018/026066
Authority: WO
Inventors: 侑香井出
Original assignee: オリンパス株式会社
Priority date: 2017-08-31
Filing date: 2018-07-10
Publication date: 2019-03-07

Abstract

The purpose of the present invention is to give sufficient bending followability and flexural rigidity to the insertion part of an endoscope using a multi-lumen tube, thereby inhibiting buckling and contributing to improvement of insertion, and providing an inexpensive endoscope insertion part. To this end, an endoscope insertion part according to the present invention is provided with: a first tube 22h having a first flexural rigidity; a second tube 22s that is provided to the leading end side of the first tube and has lower flexural rigidity than the first flexural rigidity; a net shaped pipe 23 that has the leading end thereof disposed at the leading end side relative to the first tube and that encloses the first tube and the base end section of the second tube; and a resin layer 24 that has the leading end thereof disposed on the leading end side relative to the leading end of the net shaped pipe, that is provided to the outside of the net shaped pipe, and that encloses the first tube and the second tube.

Description

Endoscope insertion section

The present invention relates to an insertion portion of an endoscope configured using a multi-lumen tube.

Conventionally, an endoscope configured to have an elongated tube-shaped insertion portion is widely used, for example, in the medical field, the industrial field, and the like.

Among them, the medical endoscope used in the medical field is, for example, inserted into the body cavity of a living body to observe an organ or the like, or the endoscope for the organ or the like is equipped as needed. It is comprised so that various treatment can be given using the treatment tool inserted in the treatment tool insertion channel.

In addition, an industrial endoscope used in the industrial field has an insertion portion inserted into, for example, a device such as a jet engine or a factory pipe, or a mechanical device, and a scratch or corrosion in the device or the mechanical device It is configured to be able to observe and inspect the condition.

In the insertion portion of a conventional endoscope of this type, it is configured to have flexible flexibility (low bending stiffness), and to be provided with a curved portion formed to be bendable by an operation at hand. Is put to practical use. By having such a configuration, the insertability of the insertion portion of the endoscope into the subject is improved.

Further, in the medical endoscope, particularly in the case of an endoscope for renal urinary tract or bronchial, etc., reduction in the diameter of the insertion portion is always desired. Therefore, in these endoscopes, there is a demand to avoid making the diameter of the insertion portion larger by complicating the bending mechanism as much as possible.

Therefore, as a configuration of the insertion portion of the conventional endoscope, for example, a flexible tubular member such as a multi-lumen tube is variously proposed by Japanese Patent Laid-Open Publication No. 2014-117397 and the like.

The insertion part of the endoscope disclosed by the above-mentioned Japanese Patent Publication No. 2014-117397 etc. is an inexpensive and thin-diameter endoscope while avoiding complication of the bending mechanism in the insertion part by using a multi-lumen tube. There is an advantage that the insertion part of can be configured.

However, in the insertion portion of the endoscope disclosed by the Japanese Patent Laid-Open Publication No. 2014-117397, etc., the insertion portion is constituted by a single multi-lumen tube, so that the required bending following property and flexibility are obtained. There is a problem that the (bending stiffness) is insufficient.

Therefore, for example, a configuration may be considered in which the insertion followability and flexibility (flexural stiffness) required for the insertion portion are provided by covering the outer surface of the multi-lumen tube with the outer skin layer. However, in the case of adopting such a configuration (a configuration in which the outer surface of the multi-lumen tube is covered with the outer skin layer), there is a problem that the multi-lumen tube tends to buckle near the end of the outer skin layer.

The present invention has been made in view of the above-described point, and the object of the present invention is to achieve sufficient bending followability and flexibility in the insertion portion of an endoscope configured using a multi-lumen tube. It is an object of the present invention to provide an inexpensive endoscope insertion portion while being able to impart (flexural stiffness) and suppress buckling of the tube, thereby contributing to an improvement in the insertability.

In order to achieve the above object, the insertion portion of the endoscope of one aspect of the present invention is provided on a first tube portion having a first bending stiffness, and on a distal end side of the first tube portion, A second tube portion having a bending stiffness lower than the first bending stiffness, and a tip end of the second tube portion having a bending stiffness lower than the first tube portion, and a base of the first tube portion and the second tube portion A reticular tube surrounding the end, and the outer end of the reticular tube, the tip of which is disposed on the tip side of the tip of the reticular tube, and surrounding the first tube portion and the second tube portion And a resin layer to be

According to the present invention, in the insertion portion of an endoscope configured using a multi-lumen tube, sufficient bending followability and flexibility (flexural stiffness) can be imparted, and buckling of the tube can be suppressed. At the same time, it can contribute to the improvement of the insertability, and at the same time, can provide an inexpensive endoscope insertion part.

The perspective view which shows schematic structure of the endoscope to which the insertion part of the endoscope of the 1st Embodiment of this invention is applied About the insertion part of the endoscope of FIG. 1, the fragmentary sectional view cut | disconnected in the direction in alignment with a long axis (insertion axis) Sectional view cut along the line [3]-[3] in FIG. About the insertion part of the endoscope of the 2nd Embodiment of this invention, the fragmentary sectional view cut | disconnected in the direction in alignment with a long axis (insertion axis) A plan view showing "blade angle" by taking out only the blade layer (reticular tube) in the insertion portion of the endoscope of Fig. 4

Hereinafter, the present invention will be described by the illustrated embodiments. The drawings used in the following description are schematically shown, and in order to show each component in a size that can be recognized in the drawing, the dimensional relationship, the scale, etc. of each member are made different for each component May be shown. Therefore, the present invention is limited to the illustrated form only with respect to the number of each component described in each drawing, the shape of each component, the ratio of the size of each component, the relative positional relationship of each component, etc. It is not limited.

First Embodiment
First, before describing the detailed configuration of the insertion portion of the endoscope according to the first embodiment of the present invention, the schematic configuration of the entire endoscope to which the insertion portion is applied will be described below with reference to FIG. Explain to. FIG. 1 is a perspective view showing a schematic configuration of an endoscope to which the insertion portion of the endoscope of the first embodiment of the present invention is applied.

The endoscope 1 is mainly configured by an insertion unit 2, an operation unit 3, a universal cord 4, an endoscope connector 5, and the like.

The insertion portion 2 is a tubular member which is formed in an elongated tube shape and is inserted into a subject. The insertion portion 2 is formed by connecting a tip portion 6, a bending portion 7 and a flexible tube portion 8 sequentially from the tip side, and has flexibility as a whole.

Among them, the distal end portion 6 is configured to have an imaging unit which is an imaging device including an imaging element and the like inside, and an illumination unit and the like (both not shown) for irradiating illumination light forward. .

In addition, as a form of the endoscope which can apply this invention, it is not limited to the above-mentioned example (an electronic endoscope provided with the imaging unit etc.), A form other than that, for example, it does not comprise an imaging unit A so-called fiberscope or the like in which the image guide fiber is disposed in the insertion portion 2 may be used.

The bending portion 7 actively bends in two directions of up and down (UP and DOWN) in response to a turning operation of the bending lever 13 for performing bending operation among operation members (described later) provided in the operation portion 3 A mechanical unit configured to be able to

In addition, as a form of the bending part in the endoscope which can apply this invention, it is not limited to the thing of the example (The type which can be bent in 2 directions of upper and lower sides) mentioned above. Of the type that can perform bending in four directions (that is, all circumferential directions around the axis of the insertion portion 2 by respective operations in the vertical and horizontal directions (UP and DOWN and RIGHT and LEFT)) including It is good.

The flexible tube portion 8 is a tubular member formed to be flexible so as to be passively flexible. Inside the flexible tube portion 8, besides the treatment tool insertion channel (described later), it extends from the imaging unit built in the distal end portion 6 and extends to the inside of the universal cord 4 through the inside of the operation portion 3 And a light guide (not shown) for guiding light emitted from various electric signal lines and a light source device (not shown) as an external device to an illumination window (not shown) provided on the tip surface of the tip portion 6 Illustration etc. are penetrated.

The light source may have a configuration in which a light emitter (for example, a light emitting diode (LED) or the like) is provided inside the operation unit. In the case of this configuration, the light guide (not shown) is used to guide the light emitted from the LED in the operation unit to the illumination window of the tip portion 6. Further, as another mode, a light emitting body such as an LED may be provided inside the distal end portion 6, for example, a portion near the base end of the illumination window. In this configuration, the light emitted from the LED is transmitted directly through the illumination window to illuminate the front of the tip 6. Therefore, in this configuration, the light guide (not shown) in the flexible tube portion 8 becomes unnecessary. On the other hand, a power supply line or the like for causing the LED provided at the distal end portion 6 to emit light is inserted into the flexible tube portion 8.

The operation unit 3 is connected to the proximal end of the insertion unit 2 and is a component unit configured to have a plurality of operation members and the like. The operation unit 3 includes a bending portion 9, a grip 10, a plurality of operation members (13, 14 and the like), a treatment tool insertion portion 11, a suction valve 15, and the like.

The folding prevention portion 9 is provided at a connection portion between the distal end portion of the operation portion 3 and the proximal end portion of the flexible tube portion 8, and covers the proximal end portion of the flexible tube portion 8. It is a protection member for preventing that the flexible tube part 8 is broken unnecessarily unnecessarily at the time of use.

The grip unit 10 is a housing unit that accommodates various constituent members inside. The gripping portion 10 is continuously provided to the fold preventing portion 9. And the holding part 10 is a site | part which a user holds and holds a hand at the time of use of the said endoscope 1. As shown in FIG.

The plurality of operation members are members provided on the outer surface of the grip portion 10 to operate various functions of the endoscope 1. As the plurality of operation members, for example, in addition to the bending lever 13 for performing the bending operation of the bending portion 7, the operation members for performing the air / water / water supply operation or the suction operation, the imaging unit, the illumination unit, etc. And the like.

The treatment instrument insertion portion 11 has a treatment instrument insertion port (not shown) for inserting various treatment instruments (not shown), and has a treatment instrument insertion path communicating with the treatment instrument insertion channel inside the operation unit 3 It is a component part. In this treatment tool insertion portion 11, a forceps plug 12 which is a lid member for opening and closing the treatment tool insertion port and is configured to be removable (replaceable) with respect to the treatment tool insertion portion 11 is disposed. ing.

The suction valve 15 is a connecting portion for connecting a suction line with a suction device (not shown).

The universal cord 4 is a hollow tubular member that is flexible and extends from the operation unit 3. The universal cord 4 is inserted from the distal end portion 6 of the insertion portion 2 through the inside of the insertion portion 2 and passes through the inside of the operation portion 3 and various signal lines and a light source device (not shown) which is an external device. The light guide and the air / water feeding tube from an air / water feeding device (not shown) which is an external device are a composite cable inserted inside.

The endoscope connector 5 is a connection member disposed at the tip of the universal cord 4 for securing connection with an external device. The endoscope connector 5 has an electrical connector portion 16 at a side surface portion for connecting a signal cable for connection with a video processor (not shown) which is an external device.

In addition, the endoscope connector 5 is a light guide connector portion for connecting a light guide bundle for connecting with a light source device (not shown) which is an external device, and an electric cable (not shown) for collecting the various signal lines. And an air / water plug 18 or the like for connecting an air / water feeding tube (not shown) from an air / water feeding device (not shown) which is an external device.

Next, the detailed configuration of the insertion portion 2 of the endoscope 1 of the present embodiment will be described below with reference to FIGS. 2 and 3. FIG. 2 is a partial cross-sectional view of the insertion portion of the endoscope of the present embodiment cut in the direction along the long axis (insertion axis). The direction in which the arrow Y1 faces in FIG. 2 is referred to as the tip end (the direction in which the tip is present), and the direction in the arrow Y2 in FIG. FIG. 3 is a cross-sectional view taken along the line [3]-[3] of FIG. That is, FIG. 3 is a view showing a cross section orthogonal to the long axis of the insertion portion.

In addition, in FIG. 2 and FIG. 3, in order to show the structure of the summary of this invention clearly while avoiding complication of drawing, illustration of the structural member which is not related to this invention is suitably abbreviate | omitted. Specifically, for example, the distal end hard member, and a part of the distal end rigid member and the exterior resin layer (the outer cover member) covering the outer surface of the curved portion are omitted.

As described above, the insertion portion 2 of the endoscope 1 of the present embodiment is formed by connecting the distal end portion 6, the bending portion 7, and the flexible tube portion 8 sequentially from the distal end side. In FIG. 2, although the distal end portion 6 is not shown, the curved portion 7 is continuously provided at the proximal end of the distal end portion 6.

In the endoscope 1 of the present embodiment, the insertion portion 2 is configured by applying, for example, a multi-lumen tube 22 (see FIGS. 2 and 3).

The multi-lumen tube 22 is a tube-shaped (tubular) member in which a plurality of holes communicating in the direction of the long axis (insertion axis) Ax (see FIG. 2) of the insertion portion 2 are formed. As shown in FIG. 3, for example, a treatment tool insertion channel hole 22a through which a treatment tool or the like is inserted, an image guide fiber, a light guide fiber, and the like are inserted through the plurality of holes formed in the multilumen tube 22. Light beam insertion hole 22b, a signal wire insertion hole 22c through which an electric signal line such as an imaging signal cable is inserted, and a bending operation wire insertion hole 22d through which a bending operation wire (not shown) is inserted (this embodiment) There are two) and so on. The bending operation wire insertion hole 22d is formed to have a diameter slightly larger than the diameter of a bending operation wire (not shown) inserted therethrough.

The multi-lumen tube 22 is formed using, for example, a flexible material such as expanded porous PTFE (ePTFE: expanded PTFE) formed by drawing PTFE (polytetrafluoroethylene), which is one of fluororesins, and processed. What applies is applied.

And in the insertion part 2 of this embodiment, as shown in FIG. 2, the multi-lumen tube 22 has a first tube portion 22 h having a first bending stiffness and a bending stiffness lower than the first bending stiffness. And the second tube portion 22s. In this case, the second tube portion 22s is provided at the tip end side of the first tube portion 22h. The portion where the second tube portion 22s is provided is a portion substantially corresponding to the curved portion 7 of the insertion portion 2.

Here, "bending stiffness" is also referred to as "bending stiffness". And, the "lower (or smaller)" "bending stiffness" is defined as being easier to deform (the deformation is larger).

That is, the second tube portion 22s forming a predetermined region (a portion substantially corresponding to the curved portion 7) near the tip of the insertion portion 2 is configured as a flexible portion that has low bending stiffness and is easily deformed. On the other hand, the first tube portion 22h provided continuously on the proximal end side of the second tube portion 22s and provided in a region near the proximal end of the insertion portion 2 (portion corresponding to the flexible tube portion 8) It is configured as a rigid portion which is high in bending stiffness and difficult to deform as compared with the tube portion 22s.

The joint portion (boundary portion) between the first tube portion 22 h and the second tube portion 22 s is referred to as a multi-lumen tube soft / soft switching portion. The multi-lumen tube rigid / soft switching portion is indicated by P3 in FIG. The arrangement of the plurality of holes in the multi-lumen tube 22 is similarly formed by the first tube portion 22 h and the second tube portion 22 s. Accordingly, the plurality of holes communicate with each other along the insertion axis from the distal end of the first tube portion 22h to the proximal end of the second tube portion 22s.

In other words, the first tube portion 22 h and the second tube portion 22 s are a multi-lumen tube in which a plurality of holes through which the long internal matter can be inserted in the direction of the longitudinal axis (long axis Ax) communicate.

The outer surface of the multi-lumen tube 22 is covered by a blade layer 23, as shown in FIG. The blade layer 23 is a net-like tube which has sufficient stretchability and bending stiffness, and is formed by alternately crossing a plurality of metal wires made of, for example, stainless steel or the like. That is, the blade layer 23 (reticular tube) is a tubular member in which a plurality of fibers are spirally knitted around a longitudinal axis (long axis Ax) at a predetermined winding pitch. With this configuration, the blade layer 23 serves to provide the insertion portion 2 with sufficient bending followability and bending stiffness.

In this case, the blade layer 23 covers at least a region including the outer surface of the multi-lumen tube soft / soft switching portion P3 and covers the outer surface of a predetermined region distal to the multi-lumen tube soft / soft switching portion P3. In addition, as shown in FIG. 2, the front-end | tip part of the blade layer 23 is shown with code | symbol P2, and suppose that this is a blade-layer front-end part.

In other words, in the blade layer 23, the tip (the blade layer tip P2) is disposed closer to the tip than the first tube portion 22h, and (substantially the entire area of) the first tube portion 22h and the second tube It is a reticular tube surrounding the proximal end portion of the portion 22s.

The outer surface of the blade layer 23 is covered with an exterior resin layer (exterior layer) 24. The exterior resin layer 24 is a tubular member having sufficient elasticity and bending stiffness, and formed of a resin member or the like.

In this case, the exterior resin layer 24 covers at least a region including the outer surface of the blade layer tip P2, and the outer surface of a predetermined region on the tip side of the blade layer tip P2 (that is, the tip portion of the curved portion 7). ) Covers substantially the entire outer surface of the flexible tube portion 8 (see FIG. 1). In addition, as shown in FIG. 2, the front-end | tip part of the exterior resin layer 24 is shown with code | symbol P1, and let this be an exterior resin layer front-end part.

In other words, the outer covering resin layer 24 is provided on the outer side of the blade layer 23 (reticular tube), and the tip (the outer covering resin layer tip P1) is closer to the tip (blade layer tip P2) of the blade layer 23 (reticular tube) It is a resin layer which is disposed on the front end side and surrounds the first tube portion 22h and the second tube portion 22s.

In this case, the exterior resin layer front end P1, the blade layer front end P2 and the multi-lumen tube hard / soft switching part P3 are arranged along the long axis Ax at a predetermined interval (for example, They are arranged side by side by about 10 mm.

By configuring the insertion portion 2 in this manner, a predetermined region (a region indicated by a symbol Bu in FIG. 2) in which the exterior resin layer distal end P1, the blade layer distal end P2, and the multi-lumen tube hard / soft switching portion P3 are provided. Functions as a buffer area (buffer area), and the buffer area Bu also functions as a passive bending section (second bending section).

That is, in the curved portion 7 in the insertion portion 2 of the endoscope 1 of the present embodiment, the bending stiffness in the buffer area Bu is gradually increased continuously or stepwise from the distal end side (deformation It is configured to be difficult).

In other words, the buffer area Bu is provided between the first tube portion 22 h and the second tube portion 22 s, and the first bending stiffness (high; hard) to the second bending stiffness (low; soft) It is a transition part that changes to

As described above, according to the first embodiment, in the insertion portion 2 of the endoscope 1 configured using the multi-lumen tube 22, the region corresponding to the curved portion 7 on the distal end side is a flexible portion A second tube portion 22s is provided, and a first tube portion 22h which is a rigid portion is continuously formed on the base end side of the second tube portion 22s.

Then, the outer surface of the multi-lumen tube 22 is covered with the blade layer 23, and the outer surface of the blade layer 23 is covered with the exterior resin layer 24. In this case, the region including the outer surface of the multi-lumen tube hard / soft switching portion P3 is covered with the blade layer 23, and the region including the outer surface of the blade layer tip P2 is covered with the exterior resin layer 24.

Then, at this time, the exterior resin layer distal end portion P1, the blade layer distal end portion P2, and the multi-lumen tube rigid / soft switching portion P3 are arranged in order from the distal end side along the long axis Ax at predetermined intervals. The buffer area Bu is formed.

As described above, by providing the buffer area Bu in the bending portion 7 of the insertion portion 2, it is possible to suppress the buckling of the multi-lumen tube 22 and to function as a passive bending portion (second bending portion). it can.

With such a configuration, in the insertion portion 2 of the endoscope 1, it is possible to provide the bending portion 7 with sufficient bending followability and bending stiffness while avoiding complication of the bending mechanism. In addition, buckling of the multi-lumen tube 22 can be suppressed. Therefore, while being able to contribute to the improvement of insertability, the structure can be simplified, and thus, the manufacturing cost can be reduced.

Second Embodiment
In the first embodiment described above, the blade layer 23 is configured to have a uniform blade mesh angle from the distal end side to the proximal end side.

Here, the “net angle of the blade” refers to an inclination angle of the mesh with respect to the major axis Ax in a blade layer formed by knitting a plurality of metal wires (see below; see FIG. 5).

The reticular tube applied to the blade layer has the property that the bendability of the tubular flexible member (insert; multi-lumen tube) covered by the reticulated tube having a larger "net angle of the blade" is lower (it becomes easier to bend) Have.

Therefore, the bending stiffness of the tubular flexible member covered by the blade layer can be controlled by using different braid angles of the mesh tube used as the blade layer.

Here, "blade mesh angle" can also be expressed as "rolling pitch". In this case, the case where the "blade mesh angle" is large and the case where the "rolling pitch" is small correspond to each other.

The endoscope insertion portion of the second embodiment described below is configured by focusing attention on the above-described point, compared with the bending stiffness in the vicinity of the buffer area Bu in the insertion portion 2A. The bending strength on the proximal side is increased. With such a configuration, bending stiffness near the buffer area Bu (passive curved portion) can be reduced. Thereby, the buckling in the buffer area Bu vicinity (passive curve part) can be suppressed.

FIG. 4 and FIG. 5 are views showing the insertion portion of the endoscope according to the second embodiment of the present invention. Among these, FIG. 4 is a partial cross-sectional view of the insertion portion of the endoscope of the present embodiment cut in the direction along the long axis (insertion axis) (a view corresponding to FIG. 2). FIG. 5 is a plan view showing “blade mesh angle” by taking out only the blade layer (reticular tube) in the insertion portion of the endoscope of the present embodiment.

The configuration of this embodiment is basically substantially the same as that of the first embodiment described above. In the present embodiment, only the configuration of the blade layer is different. Therefore, about the same composition as the above-mentioned 1st embodiment, the explanation is omitted and it explains using the same numerals, and it explains in full detail below only about a different portion.

As shown in FIGS. 4 and 5, the blade layer 23A, which is a mesh tube applied in the insertion portion of the endoscope according to the present embodiment, has “blade mesh angles” θ1, θ2, and θ3 in order from the tip side. A plurality of types of blade layers (23x, 23y, 23z) set as described above are disposed. In this case, θ1> θ2> θ3 is set.

As described above, in the present embodiment, the setting of the “blade mesh angle” of the blade layer 23A is set so that the tip end side is large and the base end side is small.

Specifically, in the present embodiment, the blade layer 23A is composed of three types of blade layers (23x, 23y, 23z) different in the setting of the “blade mesh angle”. Here, the “blade mesh angle” of the first blade layer 23 x is set to θ1. The “blade mesh angle” of the second blade layer 23y is set to θ2. The “blade mesh angle” of the third blade layer 23z is set to θ3.

Then, by arranging these three types of blade layers (23x, 23y, 23z) in order from the tip side, the “blade mesh angle” is set to be smaller stepwise (in three steps) from the tip side There is.

In other words, in the blade layer 23A, the winding pitch of the distal end region is smaller than the winding pitch of the proximal end region.

As described above, in the second embodiment described above, by adopting the above-described configuration, it is possible to achieve passiveness while securing the required flexibility (flexural stiffness) in the portion corresponding to the curved portion 7A. It is possible to lower only the flexibility (flexural stiffness) of the portion corresponding to the curved portion (a portion called a passive curved portion or a second curved portion).

The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and applications can be implemented without departing from the scope of the invention. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of a plurality of disclosed configuration requirements. For example, even if some of the configuration requirements are removed from all the configuration requirements shown in the above embodiment, this configuration requirement is eliminated if the problem to be solved by the invention can be solved and the effects of the invention can be obtained. The configuration that has been made can be extracted as the invention. Furthermore, components in different embodiments may be combined as appropriate. The invention is not limited by the specific embodiments thereof, except as limited by the appended claims.

This application is based on patent application 2017-166814 for which it applied to Japan on August 31, 2017 as a basis of a priority claim.

The contents disclosed by the above basic application are cited in the specification, claims and drawings of the present application.

The present invention can be applied not only to endoscope control devices in the medical field but also to endoscope control devices in the industrial field.

Claims

A first tube section having a first bending stiffness;
A second tube portion provided on the tip side of the first tube portion and having a bending stiffness lower than the first bending stiffness;
A reticulated tube having a distal end disposed distal to the first tube portion and surrounding the first tube portion and the proximal end portion of the second tube portion;
A resin layer provided on the outer side of the reticular tube, having a tip disposed closer to the tip than the tip of the reticular tube, and surrounding the first tube portion and the second tube portion;
An insertion part of an endoscope characterized by comprising.
2. The multi-lumen tube according to claim 1, wherein the first tube portion and the second tube portion are a multi-lumen tube in which a plurality of holes through which a long built-in material can be inserted in the direction of the longitudinal axis communicate. Insertion part of the endoscope described.
The mesh tube is a tubular member in which a plurality of fibers are spirally knitted at a predetermined winding pitch around the longitudinal axis,
The insertion part of the endoscope according to claim 1, wherein a winding pitch of a distal end region of the mesh tube is smaller than a winding pitch of a proximal end region of the mesh tube.