WO2017098786A1

WO2017098786A1 - Endoscope

Info

Publication number: WO2017098786A1
Application number: PCT/JP2016/079063
Authority: WO
Inventors: 敏弘山下; 素啓黒田
Original assignee: オリンパス株式会社
Priority date: 2015-12-09
Filing date: 2016-09-30
Publication date: 2017-06-15
Also published as: JP6257854B2; JPWO2017098786A1

Abstract

In a first bending section 40 provided with a plurality of bending pieces 45 connected so as to be capable of rotating around rotary shafts (pivot shaft parts 461, 46r), a treatment instrument channel 31 is disposed in a state decentered from an insertion axis O, light guide fiber bundles 33u, 33d, the sectional shapes of which are deformed from a circular shape, are disposed in a gap formed by decentering the treatment instrument channel 31, and the minimum width W1 of the light guide fiber bundle 33u located near the rotary shaft is set to be smaller than the minimum width W2 of the light guide fiber bundle 33d separated from the rotary shaft.

Description

Endoscope

The present invention relates to an endoscope in which a treatment instrument channel and a light guide fiber bundle are inserted into an insertion portion.

2. Description of the Related Art Conventionally, endoscopes are provided with various treatment tools using a treatment instrument inserted into a treatment instrument channel as necessary, by observing a target site in a subject by inserting a long and narrow insertion portion into a subject such as a body cavity. Used to perform treatments. The insertion portion of this type of endoscope is provided with a distal end portion, a bending portion, and a flexible tube portion in order from the distal end side, so that an operator or the like can insert the insertion portion into the subject. The bending portion can be bent in a desired direction by operating an operation knob or the like disposed in the operation portion of the endoscope while holding and pushing the flexible tube portion.

By the way, in this type of endoscope, while reducing the diameter of the insertion portion, it is strongly desired to increase the amount of transmitted illumination light by the illumination light guide (light guide fiber bundle). On the other hand, for example, in Japanese Patent Application Laid-Open No. 2005-323683, the light guide is efficiently arranged inside the insertion portion by branching the middle portion of the light guide into a plurality of light guide portions, A technique for avoiding an increase in the diameter of the insertion portion is disclosed. Japanese Patent Application Laid-Open No. 2005-323683 discloses that the cross-sectional shape of a part of the branched light guide portion is crushed in order to further improve the filling rate of the light guide in the insertion portion. Has been suggested.

However, when the cross-sectional shape of the light guide fiber bundle is flattened and deformed, a predetermined internal stress is generated in the light guide fiber bundle even before the bending operation. Therefore, the light guide fiber bundle whose cross-sectional shape is deformed in this way tends to easily cause a fiber breakage or the like when an additional stress is generated due to the bending operation of the bending portion depending on the arrangement in the insertion portion. It is in.

In particular, in an endoscope provided with a treatment instrument channel, the ratio of the area occupied by the treatment instrument channel in the insertion portion is larger than that of other built-in objects. Therefore, when the bending portion is bent while the treatment instrument is inserted into the treatment instrument channel, the light guide fiber is interfered with by the interference with the treatment instrument channel having increased hardness depending on the arrangement in the insertion section. There is a possibility that the possibility of a fiber breakage or the like becomes more remarkable due to a large movement of the bundle and the stress generated by the movement.

The present invention has been made in view of the above circumstances, and an endoscope that can achieve both reduction in diameter of the insertion portion and suppression of fiber breakage by appropriately arranging the light guide fiber bundle in the insertion portion. The purpose is to provide.

An endoscope according to an aspect of the present invention includes an insertion portion, a bending portion that is provided in the insertion portion and includes a plurality of bending pieces rotatably connected around a rotation axis, and is long in the bending portion. A treatment instrument channel inserted into the insertion portion in a state eccentric from the central axis of the direction, and a first insertion portion inserted into the insertion portion in a state where a cross-sectional shape in the bending portion is deformed with respect to a circular shape. The light guide fiber bundle, and the cross-sectional shape in the curved portion is deformed with respect to a circle so that the minimum width is larger than that of the first light guide fiber bundle, and more than the first light guide fiber bundle. And a second light guide fiber bundle inserted into the insertion portion in a state of being separated from the rotation shaft.

The perspective view which shows the structure of an endoscope The perspective view which shows the front-end | tip part of an insertion part Sectional drawing which shows the front-end | tip part of an insertion part The disassembled perspective view which shows a front-end | tip part main body, a treatment tool channel, and each fiber bundle Enlarged sectional view of the tip Sectional view along line VI-VI in FIG. Sectional view along line VII-VII in FIG. Sectional view along line VIII-VIII in FIG. Explanatory drawing which shows the state at the time of inserting an insertion part into the upper lobe bronchus Sectional drawing of the principal part of a 1st curved part concerning a 1st modification. Sectional drawing of the principal part of a 1st curved part concerning a 2nd modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a perspective view showing a configuration of an endoscope, FIG. 2 is a perspective view showing a distal end portion of an insertion portion, and FIG. 3 is a cross-sectional view showing a distal end portion of the insertion portion. 4 is an exploded perspective view showing the distal end portion main body, the treatment instrument channel, and each fiber bundle, FIG. 5 is an enlarged sectional view of the distal end portion, FIG. 6 is a sectional view taken along line VI-VI in FIG. 3, and FIG. 3 is a sectional view taken along line VII-VII, FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 3, and FIG. 9 is an explanatory view showing a state when the insertion portion is inserted into the upper lobe bronchus.

An endoscope 1 shown in FIG. 1 is, for example, an endoscope for bronchi (bronchoscope). The endoscope 1 includes a long insertion portion 2 that can be inserted into a target site such as a bronchus in a subject, an operation portion 3 that is connected to the proximal end side of the insertion portion 2, and a side of the operation portion 3. And a universal cord 4 extending from the section.

The operation unit 3 has an operation unit main body 10 constituting an operation gripping unit, and a distal end side of the operation unit main body 10 is connected to a proximal end side of the insertion unit 2 through a bend preventing unit 11. Further, near the distal end of the operation unit main body 10, a treatment that serves as an opening on the proximal end side of a treatment instrument channel 31 (see FIGS. 2 to 8), which is a conduit for inserting the treatment instrument into the insertion portion 2. A tool insertion port 13 is provided. On the other hand, an angle lever 14 and switches 15 for various endoscope functions are provided near the proximal end of the operation unit main body 10.

The one end side of the universal cord 4 is connected to the side part of the operation part main body 10 via the bend preventing part 16. On the other hand, a scope connector portion 20 is provided at the extended end which is the other end side of the universal cord 4. A light source side connector 21 detachably attached to a light source device (not shown) is provided at the end of the scope connector unit 20. The light source side connector 21 is provided with a proximal end portion of a light guide fiber bundle extending from the insertion portion 2 side, and an electrical contact 22 is provided. Thus, when the light source side connector 21 is connected to the light source device, the light guide fiber bundle is optically connected to the light source in the light source device, and the electrical contact 22 is electrically connected to the power source in the light source device. The In addition, an electrical connector 23 detachably attached to a video processor (not shown) is provided on the side of the scope connector unit 20.

As shown in FIGS. 1 to 3, the insertion portion 2 includes a distal end portion 5, a bendable bending portion 6 disposed on the proximal end side of the distal end portion 5, and a proximal end side of the bending portion 6. A long and flexible flexible tube portion 7 is connected in order from the tip.

For example, as shown in FIGS. 3 and 5, the distal end portion 5 is made of a metal tip portion main body 25 having a substantially columnar shape, and a metal shape having a substantially cylindrical shape continuously provided on the base end side of the tip portion main body 25. The most advanced bending piece 45a.

As shown in FIG. 4, the distal end body 25 is provided with a channel port 26, an observation optical system holding hole 27, and a pair of upper and lower illumination optical

system holding holes

28u and 28d. Here, in the present embodiment, the channel opening 26 which is the largest opening is disposed in the distal end portion body 25 in a state of being eccentric from the insertion axis O which is the central axis in the longitudinal direction of the insertion portion 2. The pair of illumination optical

system holding holes

28u and 28d are arranged along the outer periphery of the channel port 26 at a position sandwiching the observation optical system holding hole 27 vertically.

The distal end side of the treatment instrument channel 31 inserted into the insertion portion 2 is held in the channel port 26 on the proximal end side of the distal end portion main body 25. Specifically, for example, as shown in FIGS. 4 to 6, the treatment instrument channel 31 of this embodiment includes a fluororesin layer 31a, an intermediate layer 31b, a blade 31c, and an exterior 31d in order from the inner peripheral side. It is composed of laminated multi-layered tubes. In the treatment instrument channel 31, a part of the outer layer side (for example, the blade 31c and the exterior 31d) is removed on the distal end side, and the region on the distal end side where a part of the outer layer side is removed in this way. It is inserted into the channel port 26. Accordingly, the distal end side of the treatment instrument channel 31 is held by the distal end portion body 25 and communicated with the channel port 26.

Further, on the distal end side of the distal end portion body 25, an observation optical system 29 for observing the subject is held in the observation optical system holding hole 27, and the illumination optical

system holding holes

28u and 28d illuminate the inside of the subject. Illumination

optical systems

30u and 30d for holding are respectively held.

On the other hand, on the proximal end side of the distal end portion main body 25, the distal end side of the image guide fiber bundle 32 as an optical image transmission member inserted into the insertion portion 2 is held in the observation optical system holding hole 27. Specifically, for example, as shown in FIG. 4, the image guide fiber bundle 32 of the present embodiment is basically inserted into the insertion portion 2 in a state surrounded by the outer tube 32a. The region on the distal end side of the image guide fiber bundle 32 is partially exposed from the outer tube 32a, and the region exposed from the outer tube 32a is inserted into a hard pipe 35 made of stainless steel or the like, and further the observation optical system. It is inserted into the holding hole 27 (see FIGS. 4 to 6). Thereby, the distal end side of the image guide fiber bundle 32 is held by the distal end portion body 25 and optically connected to the observation optical system 29.

Further, on the proximal end side of the distal end portion body 25, the distal ends of the pair of upper and lower light

guide fiber bundles

33u and 33d inserted into the insertion portion 2 are held in the illumination optical

system holding holes

28u and 28d, respectively. . Specifically, for example, as shown in FIGS. 4 and 6, the light

guide fiber bundles

33 u and 33 d of the present embodiment are basically enclosed in the outer tube 33 ua and 33 da in the insertion portion 2. Is inserted. The light

guide fiber bundles

33u and 33d are partially exposed from the outer tubes 33ua and 33da, and the regions exposed from the outer tubes 33ua and 33da correspond to the illumination optical

system holding holes

28u and 28u, respectively. 28d is inserted. Thus, the distal ends of the light

guide fiber bundles

33u and 33d are held by the distal end body 25 and are optically connected to the corresponding illumination

optical systems

30u and 30d, respectively. Although not shown, the light

guide fiber bundles

33u and 33d of the present embodiment are combined into a single light guide fiber bundle on the proximal end side in the insertion portion 2, and then passed through the operation portion 3 to the universal cord 4 The light source side connector 21 is optically connected.

Then, a part of the outer layer side (blade 31c and exterior 31d) constituting the treatment instrument channel 31 is removed and inserted into the channel port 26, and exposed from the exterior tubes 32a, 33ua, and 33da. By inserting the guide fiber bundle 32 and the light

guide fiber bundles

33u and 33d into the rigid pipe 35 and inserting them into the observation optical system holding hole 27 and the illumination optical

system holding holes

28u and 28d, respectively, the channel port 26 and the observation optics are inserted. An increase in the diameter of the opening on the base end side of the system holding hole 27 and the illumination optical

system holding holes

28u and 28d is suppressed. As a result, it is possible to reduce the diameter of the tip body 25 while ensuring the rigidity of the tip body 25.

As shown in FIG. 5, the proximal end of the region where a part of the outer layer side of the treatment instrument channel 31 is removed, the proximal end of the region exposed from the outer tube 32 a of the image guide fiber bundle 32, and The proximal ends of the regions exposed from the outer tubes 33 ua and 33 da of the light

guide fiber bundles

33 u and 33 d are set in the most advanced bending piece 45 a constituting the distal end portion 5. Then, by removing the outer tubes 32a, 33ua, and 33da only in the distal end portion 5 where the bending operation is not performed in this way, it is possible to avoid an excessive load from the treatment instrument or the like from acting on the region. It becomes. In addition, by covering the region from which the outer tube 32a has been removed with the hard pipe 35 having a diameter smaller than that of the outer tube 32a, it is possible to more accurately avoid an excessive load from the treatment instrument or the like. . As described above, it is possible to secure resistance as a scope while realizing a reduction in the diameter of each of the fiber bundles 32, 33u, and 33d in the distal end portion 5.

Here, in the above-described example, the configuration in which the hard pipe is covered only on the region where the outer tube 32a of the image guide fiber bundle 32 is removed is described. However, the outer tubes 33ua and 33da of the light

guide fiber bundles

33u and 33d are attached. The removed area may be covered with a hard pipe having a diameter smaller than that of the outer tubes 33ua and 33da.

As shown in FIGS. 1 and 2, the bending portion 6 includes, for example, a first bending portion 40 that can be freely bent in two vertical directions in conjunction with a bending operation through the angle lever 14 of the operation portion 3, and a first bending portion 40. And a second bending portion 41 that is disposed on the proximal end side of the first bending portion 40 and passively bends by an external force.

As shown in FIG. 3, the first bending portion 40 includes, for example, a plurality of metal bending pieces 45 having a substantially annular shape, and pivots 46 l and 46 r such as rivets that form pairs on the left and right sides. As shown, it has a curved structure 47 that is rotatably connected.

The most advanced bending piece 45a that constitutes the above-described distal end portion 5 is connected to the most distal end of the bending structure 47. On the other hand, the most proximal end bending piece 45b positioned at the most proximal end of the bending structure 47 is fitted into the distal end side of the base 50 having a cylindrical shape, and is fixed by brazing or the like.

For example, as shown in FIGS. 3 and 7, a pair of upper and lower wire guides 48 u and 48 d are provided on the inner periphery of the predetermined bending piece 45, and each

wire guide

48 u and 48 d is connected to the angle lever 14. Two bending

operation wires

51u and 51d are inserted. The distal ends of the

bending operation wires

51u and 51d inserted through the wire guides 48u and 48d extend into the distal end portion 5 and are respectively provided by wire stoppers 52 provided on the inner periphery of the most advanced bending piece 45a. It is fixed. Then, when these bending

operation wires

51u and 51d are pulled or relaxed by operating the angle lever 14, the first bending portion 40 can actively bend in the vertical direction. Yes.

On the other hand, for example, as shown in FIGS. 3 and 8, the second bending portion 41 is a first flex made of a compression coil spring formed by, for example, spirally winding a strip-shaped spring steel made of stainless steel or the like. 55. The outer periphery of the first flex 55 is covered with a cylindrical blade 56 formed by weaving a thin metal wire such as stainless steel. In addition, the base end side of the base 50 is externally fitted to the distal end side of the first flex 55 and the blade 56 covered on the outer periphery thereof, and is fixed by brazing or the like.

Further, in the first and

second bending portions

40 and 41, the outer periphery of the bending structure 47 and the blade 56 is integrally covered with a first outer skin 57 made of, for example, a soft rubber or the like. ing. Note that the distal end side of the first outer skin 57 is liquid-tightly bonded and fixed to, for example, the outer peripheral portion of the distal end portion main body 25.

In the first and

second bending portions

40 and 41 configured as described above, for example, as shown in FIGS. 7 and 8, the treatment instrument channel 31 in which the distal end side body 25 holds the distal end region, The image guide fiber bundle 32 and the light

guide fiber bundles

33u and 33d are inserted.

As shown in FIG. 7, in the first bending portion 40, the treatment instrument channel 31 is arranged in an eccentric state from the insertion axis O, similarly to the arrangement at the distal end portion 5. More specifically, the treatment instrument channel 31 of the present embodiment has one pivot portion (for example, the right pivot portion 46r) of the pivot portions 46l and 46r whose outer peripheral surfaces form a pair on the left and right, and It arrange | positions so that it may contact | abut one wire guide (for example, upper wire guide 48u) of the wire guides 48u and 48d which make a pair vertically. Thereby, the treatment instrument channel 31 is arranged so that the center O1 is located on one side with a straight line connecting the pair of wire guides 48u and 48d as a boundary.

In the first bending portion 40, the image guide fiber bundle 32 and the light

guide fiber bundles

33u and 33d are arranged in a gap formed by eccentricizing the treatment instrument channel 31. More specifically, the image guide fiber bundle 32 and the light

guide fiber bundles

33u and 33d are arranged along the outer peripheral surface of the treatment instrument channel 31 so that the pair of upper and lower light

guide fiber bundles

33u and 33d sandwich the image guide fiber bundle 32. Arranged in a row.

Thereby, the image guide fiber bundle 32 and the light

guide fiber bundles

33u and 33d are disposed on the other side with a straight line connecting the pair of wire guides 48u and 48d as a boundary. The upper light guide fiber bundle 33u is disposed as a first light guide fiber bundle in the vicinity of the rotating shaft (left pivot portion 46l), and the lower light guide fiber bundle 33d is a second light guide fiber bundle. Are arranged at positions separated from the rotation shaft (left pivot portion 46l).

Here, the outer tube 32a, 33ua, 33da is a flexible resin such as PTFE (polytetrafluoroethylene) so that the cross-sectional shape of the image guide fiber bundle 32 and the light

guide fiber bundles

33u, 33d can be deformed. Consists of materials. Each of the exterior tubes 32a, 33ua, and 33da is formed of PTFE or the like, so that the image guide fiber bundle 32 and the light

guide fiber bundles

33u and 33d have a basic cross-sectional shape according to the shape of the gap. It is arranged in the first bending portion 40 in a state of being deformed with respect to a certain circular shape.

In this case, the lower light guide fiber bundle 33d arranged as a second light guide fiber bundle at a position separated from the rotation axis has a minimum width W2 due to the deformation of the lower light guide fiber bundle 33d as the first light guide fiber bundle. It is set to be relatively larger than the minimum width W1 due to the deformation of the upper light guide fiber bundle 33u disposed in the vicinity of the dynamic axis. Here, the light

guide fiber bundles

33u and 33d of the present embodiment are constituted by fiber bundles having the same cross-sectional area so as to irradiate the illumination light of the same light amount from the illumination

optical systems

30u and 30d. For this reason, the upper light guide fiber bundle 33u is flatly deformed with a larger deformation amount (collapse amount) than the lower light guide fiber bundle 33d in order to make the minimum width W1 smaller than the minimum width W2. .

In order to realize the deformation by such a large deformation amount, the outer tube 33ua of the upper light guide fiber bundle 33u has the same flexibility as the outer tube 33da of the lower light guide fiber bundle 33d, or the outer tube Although it is possible to employ a tube that is more flexible than the tube 33da, it is more desirable that the tube be more flexible than the outer tube 33da. In this case, the hardness adjustment of each of the outer tubes 33ua, 33da, etc. can be easily realized by adjusting the porosity when PTFE is used as a material, for example.

For example, the outer tube 33ua of the upper light guide fiber bundle 33u can be made of PTFE having a porosity of around 40% in order to facilitate deformation.

On the other hand, in the present embodiment, the outer tube 33da of the lower light guide fiber bundle 33d is disposed adjacent to the lower wire guide 48d. In this case, in the bending operation or the like of the bending portion 6, the lower light guide fiber bundle 33 d is prevented from moving over the lower wire guide 48 d while greatly deforming the cross-sectional shape thereof, and thus has a predetermined flexibility. It is desirable to have a certain degree of hardness while ensuring the above. For this reason, for example, the outer tube 33da of the lower light guide fiber bundle 33d is preferably made of PTFE having a porosity of around 15%.

For example, as shown in FIG. 8, in the second bending portion 41, the treatment instrument channel 31, the image guide fiber bundle 32, and the light

guide fiber bundles

33u and 33d are arranged in the first bending portion 40. Although arranged in substantially the same manner, the upper and lower light

guide fiber bundles

33u and 33d have their minimum widths in the second bending portion 41 which is a passive bending portion without the pivot portions 46l and 46r. Are deformed so as to be equivalent to each other (that is, to have the same amount of crushing).

The flexible tube portion 7 has a second flex 58 made of a compression coil spring formed by, for example, spirally winding a strip-shaped spring steel made of stainless steel or the like. The outer periphery of the second flex 58 is covered with, for example, a blade 56 extending from the second bending portion 40 side.

Furthermore, in the flexible tube portion 7, the outer periphery of the blade 56 is covered with a second outer skin 59 made of a tube made of, for example, a resin having a predetermined hardness. The distal end side of the second outer skin 59 is, for example, liquid-tightly bonded and fixed to the outer periphery of the proximal end side of the first outer skin 57, and the proximal end side of the second outer skin 59 is not bent. It extends inside the portion 11.

In the present embodiment, the second flex 58 is made of spring steel integrated with the first flex 55. In this case, the flexible tube portion 7 has a bending rigidity relatively higher than that of the second bending portion 41 by the second skin 59.

Incidentally, as described above, the bending stiffness of the endoscope 1 changes at the boundary between the second bending portion 41 and the flexible tube portion 7 in the insertion portion 2. Such a boundary portion where the bending rigidity changes abruptly may cause a buckling deformation in the middle of the insertion portion 2 when it reaches a bent portion on a pipe line having a large bending angle. When such a buckling deformation occurs in the insertion portion 2, the force is dispersed at the buckled portion, so that even if the insertion portion 2 is further pushed in, further advancement may be difficult. . For this reason, the endoscope 1 of the present embodiment is configured so that the second bending portion 41 and the flexible tube portion in the insertion portion 2 are provided so as to prevent buckling of the insertion portion 2 and realize insertion as far as possible to the periphery. 7 is optimized.

Specifically, the endoscope 1 according to the present embodiment, which is a bronchoscope, has a second portion from the distal end of the insertion portion 2 to prevent buckling when the insertion portion 2 is inserted into the bronchus of the upper lobe. The length to the boundary between the bending portion 41 and the flexible tube portion 7 is optimized.

That is, for example, as shown in FIG. 9, in the lung bronchus 100, the primary branch 101 toward the upper lobe is bent at the largest bending angle (about 60 °). Therefore, in order to advance the insertion portion 2 further to the distal end than the primary branch 101, the distal end side of the insertion portion 2 is set in a direction opposite to the insertion direction on the hand side while preventing buckling in the primary branch 101. It needs to be advanced.

Here, when the insertion part 2 is inserted, assuming that the bronchial diameter can be expanded to about twice the normal time, and considering the deepest position where the insertion part 2 can be inserted based on bronchial anatomy data, For example, the insertion portion 2 having a tip 5 having a diameter of 3 mm can be inserted up to the ninth branch 109 having a bronchial diameter of about 1.5 mm in terms of anatomy. Here, according to the bronchial anatomy data or the like, the distance from the upper trunk entrance to the upper branch side ninth branch 109 is about 81 mm. Therefore, even when the distal end portion 5 reaches the deepest insertable portion, the boundary between the second bending portion 41 and the flexible tube portion 7 is positioned closer to the proximal side than the primary branch 101 to prevent buckling. Therefore, in the insertion portion 2 of the present embodiment, the length L from the distal end of the insertion portion 2 to the boundary between the second bending portion 41 and the flexible tube portion 7 is set to 81 mm or more. As described above, since the maximum distance that can be inserted into the bronchus depends on the outer diameter of the distal end portion 5, it is desirable that the length L be appropriately changed according to the outer diameter of the distal end portion 5. That is, when the outer diameter of the distal end portion 5 is large, the maximum distance that can be inserted into the bronchus is shortened so that the length L can be shortened. Conversely, when the outer diameter of the distal end portion 5 is small. Since the maximum distance that can be inserted into the bronchus is increased, the length L needs to be increased.

According to such an embodiment, the treatment instrument channel 31 is disposed in the first bending portion 40 including the plurality of bending pieces 45 that are rotatably connected around the rotation shafts (the pivot portions 46l and 46r). The light

guide fiber bundles

33u and 33d whose cross-sectional shape is deformed with respect to a circle are arranged in a gap formed by decentering the insertion axis O, and the treatment instrument channel 31 being decentered. By setting the minimum width W1 of the light guide fiber bundle 33u located in the vicinity of the moving axis to be smaller than the minimum width W2 of the light guide fiber bundle 33d separated from the rotation axis, the diameter of the insertion portion 2 can be reduced. And suppression of disconnection of each light

guide fiber bundle

33u, 33d can be achieved.

That is, by making the light

guide fiber bundles

33u and 33d flat, the filling rate in the first bending portion 40 can be improved, and the diameter of the insertion portion 2 can be reduced. At that time, focusing on the fact that the light

guide fiber bundles

33u and 33d are arranged at positions away from the rotation shaft, the amount of movement during the bending operation increases, and a relatively large internal stress is generated. Each light guide fiber bundle 33u has a relationship in which the minimum width W2 of the light guide fiber bundle 33d arranged away from the rotation axis is larger than the minimum width W1 of the light guide fiber bundle 33u arranged in the vicinity of the moving axis. , 33d can be used to prevent excessive internal stress from occurring in a specific light guide fiber bundle and to effectively suppress fiber breakage.

In this case, by setting the light

guide fiber bundles

33u and 33d to the same cross-sectional area, it is possible to equalize the amount of illumination light emitted from the illumination

optical systems

30u and 30d to the subject.

Here, in the above-described embodiment, an example in which the pair of upper and lower light

guide fiber bundles

33u and 33d have the same cross-sectional area has been described. However, the required illumination light characteristics and the inside of the first bending portion 40 are described. For example, as shown in FIG. 10, the cross-sectional areas of the light

guide fiber bundles

33u and 33d can be set unequal, depending on the shape of the gaps in FIG.

In the above-described embodiment, an example in which a pair of upper and lower light

guide fiber bundles

33u and 33d is arranged in the first bending portion 40 has been described. However, three or more light guide fiber bundles can be arranged. It is. For example, FIG. 11 illustrates a case where three light

guide fiber bundles

34 u, 34 m and 34 d are arranged in the first bending portion 40. In this case, each light

guide fiber bundle

34u, 34m, 34d is deformed so that the minimum width of the light guide fiber bundle 34u is the smallest and the minimum width of the light guide fiber bundle 34d is the largest. That is, in the relationship between the light guide fiber bundle 34u and the light guide fiber bundle 34m, the light guide fiber bundle 34u positioned relatively near the rotation axis corresponds to the first light guide fiber bundle, and the light guide fiber bundle 34 m corresponds to the second light guide fiber bundle. Further, in the relationship between the light guide fiber bundle 34m and the light guide fiber bundle 34d, the light guide fiber bundle 34m relatively positioned near the rotation axis corresponds to the first light guide fiber bundle, and the light guide fiber bundle. 34d corresponds to the second light guide fiber bundle. It is desirable that the outer tubes 34ua, 34ma, 34da surrounding the light

guide fiber bundles

34u, 34m, 34d are also more flexible as they are located near the rotation shaft.

The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention. For example, it is needless to say that the configurations of the above-described embodiment and each modification may be combined as appropriate.

In the above-described embodiment, an example in which the image guide fiber bundle 32 is used as an optical image transmission member has been described. However, for example, in an endoscope in which an imaging element such as a CCD is built in the distal end portion 5. Of course, the optical image transmission member may be a signal line for transmitting the captured optical image as an electrical signal.

This application is filed on the basis of the priority claim of Japanese Patent Application No. 2015-240464 filed in Japan on December 9, 2015, and the above disclosure is included in the present specification and claims. Shall be quoted.

Claims

An insertion part;
A bending portion provided with a plurality of bending pieces provided in the insertion portion and rotatably connected around a rotation axis;
A treatment instrument channel inserted in the insertion portion in a state of being eccentric from the longitudinal central axis in the bending portion;
In a state where the cross-sectional shape in the curved portion is deformed with respect to a circular shape, a first light guide fiber bundle inserted through the insertion portion,
A state in which the cross-sectional shape in the bending portion is deformed with respect to a circle so that the minimum width is larger than that of the first light guide fiber bundle, and the first light guide fiber bundle is separated from the rotating shaft. An endoscope, comprising: a second light guide fiber bundle inserted through the insertion portion.
The first light guide fiber bundle and the second light guide fiber bundle have the same cross-sectional area;
The endoscope according to claim 1, wherein the first light guide fiber bundle is deformed flatter than the second light guide fiber bundle.
2. The optical image transmission member for transmitting an optical image of a subject is disposed between the first light guide fiber bundle and the second light guide fiber bundle. Endoscope.
The first light guide fiber bundle and the second light guide fiber bundle each have an outer tube surrounding each;
The outer tube of the first light guide fiber bundle has the same flexibility as the outer tube of the second light guide fiber bundle, or from the outer tube of the second light guide fiber bundle. The endoscope according to claim 1, which is also flexible.
A pair of wire guides facing each other in the curved portion;
The treatment instrument channel is arranged so that the center is located on one side with a straight line connecting the pair of wire guides as a boundary,
The first light guide fiber bundle, the second light guide fiber bundle, and the optical image transmission member are disposed on the other side with a straight line connecting the pair of wire guides as a boundary. The endoscope according to claim 3.