JP2563969B2 - Endoscope for small diameter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an endoscope for small diameter with an improved optical fiber bundle in a curved portion of an insertion portion of an endoscope inserted into a body cavity.

[Conventional technology]

Generally, an endoscope is composed of an operation part on the proximal side and an elongated flexible insertion part to be inserted into a body cavity. The operation part is provided at the distal end side part of this insertion part. A bending portion is provided which allows bending operation in a desired direction by rotating the bending operation knob.

An optical fiber bundle used as a light guide or an image guide is inserted inside the insertion portion. At the tip portion of this optical fiber bundle, the fibers are hardened together by an adhesive agent to form a hard portion, which is fixed to the tip forming portion of the insertion portion. Therefore, when the bending portion is bent by the bending operation knob, the flexibility of the optical fiber bundle except the hard portion is also bent. When the curved portion is bent in this way, the optical fiber bundle inside it contacts other air supply and water supply tubes, treatment tubes, etc., and the optical fibers fatigue due to repeated stress due to the frictional resistance of the optical fibers, causing breakage. There was something to do.

For this reason, conventionally, for example, as in JP-A-59-87409, the outer tube that covers the outer circumference of the optical fiber bundle is made flat so as not to be flatly crushed even during bending, so that the friction resistance of the optical fibers can be reduced. It has been proposed to reduce the number of folds so that it is hard to break.
Double tube as in No. 02, JP-A-59-8741
Some of them, such as No. 0, are reinforced with spiral tubes of synthetic resin.

[Problems to be solved by the invention]

However, even if the above measures are taken, the optical fiber bundle may be broken. In particular, it is necessary to insert it into a relatively small lumen in the body cavity.For example, in the case of a small-diameter endoscope for bronchus, biliary tract, urethra, or nasal cavity, where the outer diameter of the insertion part is 6 mm or less, the optical fiber bundle If a part of the optical fiber is broken at the tip of the optical fiber, once the optical fiber is broken, stress concentrates on that part, and each time the bending operation is repeated, the bending of the optical fiber increases at the same part. Even in a tube coated with optical fibers, it may almost break. As a result, for example, in the case of an optical fiber bundle for a light guide, bright illuminating light cannot be obtained, and in an endoscope having a plurality of illuminating light emitting windows formed in the distal end configuration portion, the illuminating light from one side disappears and the field of view decreases. There were drawbacks such as poor light distribution inside.

The present invention has been made in view of the above circumstances, and the purpose thereof is to distribute the light distribution in the visual field without all the optical fibers being broken even if the bending portion of the insertion portion of the endoscope is repeatedly bent. Provide a good thin endoscope.

[Means and Actions for Solving Problems]

The optical fiber bundle is divided into a plurality of optical fiber bundles at least over the entire length of the curved portion, at least a part of the optical fiber bundles of the divided optical fiber bundles are formed in a rigid portion fixed to each other, A small-diameter endoscope that is arranged in the distal end configuration portion.

With such a configuration, when the curved portion is bent, even if one optical fiber bundle in the portion corresponding to the curved portion is broken, it can be illuminated by the light distribution of the other optical fiber bundle.

〔Example〕

A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 2 is a view showing the entire endoscope, and the endoscope 1 is a universal cord connected to an operating portion 2 on the proximal side, an elongated insertion portion 3 to be inserted into a body cavity, and a light source device. 4 and. In addition to the bending operation knob 5, the operation section is provided with an eyepiece section 6 for observing an affected area in the body cavity. The insertion portion 3 is connected to the distal end of the flexible tube portion 7 via a curved portion 8 and a tip forming portion 9, and the curved portion 8 has one end fixed to the curved operation knob 5 of the operation portion 2 and the other. By rotating the bending operation knob 5 by the bending operation wire 10 whose end is fixed to the tip forming portion 9, the wire 10 is pulled and bent in a desired direction.

Further, as shown in FIG. 1, the curved portion 8 is provided with a plurality of short tubular joint rings 11a, 11b, 11c which are sequentially pivoted in the longitudinal direction thereof, and each joint ring 11a, 11b, 11c is provided with a rivet 12. Connected by. Centering around this rivet 12, each node ring 11a, 11
The b and 11c can be freely rotatably curved. The outer circumferences of the node rings 11a, 11b, 11c are covered with a flexible tubular outer cover 13. The end of the node ring 11c on the tip side is fixed to the tip forming portion 9, and the node ring 11 on the end located on the rear end side.
The a is connected to the flexible tube portion 7 via the connecting tube 14. The flexible tube portion 7 is freely flexible by being coated with a flexible outer skin 17 on the outer periphery of a core material composed of a flex 15 in which a metal plate is spirally wound and a blade 16 in which a fiber or the like is knitted in a mesh shape. To have. Then, various interior members necessary for the endoscope 1 are inserted into the insertion portion 3. That is, the light guide optical fiber bundle 18, the image guide optical fiber bundle 19, the forceps channel flexible tube (not shown), and the like are inserted. Each of the above optical fibers
18 and 19 are formed by bundling a large number of elongated optical fibers. The ends of each optical fiber bundle 18 and 19 are hardened with adhesive to form hard parts 20 and 21, and The tip side is fixed. Optical fiber bundle 18 for the light guide
Is formed of one optical fiber bundle 18 from the operation portion 2 side to the flexible tube portion 7, but is a node ring 11 that constitutes the curved portion 8.
In the section from a to node ring 11c, two optical fiber bundles 18
The optical fiber bundle 18 is divided into a and 18b and is formed into one optical fiber bundle 18 at the tip forming portion 9. Each optical fiber bundle 18,18
The outer circumferences of a and 18b are covered with flexible protective tubes 22, 22a and 22b made of synthetic rubber such as silicon rubber having a good surface smoothness. Further, the tip end surface of the hard portion 20 is polished to be smooth and is connected to the lens 23 of the illumination optical system.

On the other hand, the image guide optical fiber bundle 19 is connected to the eyepiece 6 of the operation unit 2 on the proximal end side and is optically connected to the objective lens 24 of the observation optical system on the distal end side, except for the hard portion 21. The outer circumference of the optical fiber bundle 19 is covered with a protective tube 25.

In order to bend the curved portion 8 of the insertion portion 3 of the endoscope 1 having the above configuration in a desired direction, the curved operation knob 5 of the operation portion 2 is used.
The optical fiber bundle 18a for the divided light guide, which is inserted through the curved portion 8 by rotating the optical fiber bundle 18a,
The light guide optical fiber bundles 18b, each of which is also curved in the same direction, are divided into two in the bending portion 8, so that the bending is repeated, and one portion of one fiber bundle is bent, Even if most of the fiber in the protective tube breaks due to the concentration of stress on the part,
Since the illumination light guided by the other fiber bundle is applied to the visual field, the illumination light will not be lost at all.

Next, FIG. 3 shows a second embodiment of the optical fiber bundles 26, 27 for a light guide. The light guide optical fiber bundles 26, 27 are arranged in the curved portion 8 and the distal end forming portion 9 of the insertion portion 3 of the endoscope 1 as in the first embodiment except that the configurations thereof are different. Details are omitted. The tip portions 28 and 29 of the light guide optical fiber bundles 26 and 27 are independent of each other at the rear end of the lens of the illumination optical system for emitting the two illumination lights of the tip forming portion 9 as in the first embodiment. Is provided. The tip portions are hard tip portions 28 and 29 that are hardened with an adhesive. The optical fiber bundles 26 and 27 of the light guide optical fiber bundle are divided into two in the longitudinal direction between the node rings 11a and 11b inside the curved portion 8 and are arranged in the longitudinal direction. The two optical fibers 26 and 27 are each divided at an appropriate ratio to form a divided portion 30, and the two optical fibers 26 and 27 are further intersected with each other to form tip portions 28 and 29 in which the respective optical fiber bundles 26 and 27 are mixed. It is divided into and arranged as a hard part. Further, the outer circumferences of the light guide optical fiber bundles 26, 27 in the curved portion 8 after the dividing portion 30 are covered with flexible outer tubes 31, 32.

By doing this, the optical fiber bundle for the light guide 26,2
Even if the fibers in the outer tube 31, 32 of either one of 7 are almost broken, the illumination light emitted from one of the lenses of the two illumination optical systems is emitted from both the tip surfaces. Therefore, the light distribution in the visual field does not deteriorate.

Further, in the first and second embodiments, the optical fiber bundle for light guide is shown, but other optical fiber bundles arranged in the curved portion may be used.

〔The invention's effect〕

As described above, it is divided into a plurality of optical fiber bundles over at least the entire length of the curved portion, and at least a part of the optical fiber bundles thus divided are fixed to each other to form a hard portion,
In the small-diameter endoscope in which the hard portion is arranged in the distal end configuration portion, even if a part of one optical fiber bundle starts to be broken and all the fibers in the optical fiber bundle are broken, Since there is a light distribution with the optical fiber, the illumination light will not be extinguished at all, so it is possible to safely observe.

[Brief description of drawings]

FIG. 1 is a side cross-sectional view showing a first embodiment of the present invention in the vicinity of a curved portion of an insertion portion, FIG. 2 is a front view showing the same endoscope as a whole, and FIG. 3 is a second embodiment of the present invention. It is a side sectional view of an optical fiber bundle for a light guide showing an example. 3 …… Insertion part 8 …… Bending part 9 …… Tip part 18,18a, 18b, 26,27 …… Optical fiber bundle for light guide 22,22a, 22b, 31,32 …… Outer tube

Claims (1)

(57) [Claims] 1. A flexible insertion portion is provided with a bending portion capable of bending in a desired direction at a tip side portion thereof, and a tip forming portion located on a tip side of the bending portion, and further inside the insertion portion. In a small-diameter endoscope in which an optical fiber bundle composed of a large number of optical fibers is inserted and the distal end portion of this optical fiber bundle is fixed to a distal end configuration portion, the optical fiber bundle is a plurality of at least over the entire length of the curved portion. The optical fiber bundle is divided into optical fiber bundles, and at least a part of the divided optical fiber bundles is formed in a rigid portion fixed to each other, and the hard portion is arranged in the tip forming portion. Endoscope for small diameter.