JPS6348243Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an endoscope that reduces breakage of optical fiber bundles in curved portions of an insertion section of an endoscope that is inserted into a body cavity.

BACKGROUND ART Medical endoscopes are required to minimize patient pain when inserting the endoscope into a patient's body cavity. For this reason, the outer diameter of the insertion tube may be
It is desirable to make it as thin as 0.1 mm. Therefore, it is desirable that the optical fiber bundle conducted through the insertion section be thin, but there is a limit to this due to the need to secure an observation field of view, and for this reason, it is required that the outer sheath be made as thin as possible.

As explained below with reference to the drawings, conventionally, a flexible thin-walled tube 15 such as a silicone tube, rubber tube, or plastic tube with a wall thickness of about 0.1 to 0.2 mm has been used as the exterior (see FIG. 5). . On the other hand, the insertion portion A, whose outer diameter is reduced to the maximum limit, is equipped with optical fiber bundles 7 and 8 for image transmission and illumination, as well as a biopsy tool such as forceps. Built-in are a channel 9 for insertion, channels 10 and 11 for air supply and water supply, an operation wire 12 for bending the tip curved portion, and the like. In this way, in order to store many types of built-in items in a limited space, each built-in item is stored in an extremely crowded state, and as a result, the tip curved portion 4 of built-in items such as optical fiber bundles is Curved part 4 every time it curves
They slide against each other within the flexible tube 3, causing repeated mutual pressure.

Normally, the curved portion 4 of the endoscope is constructed by sequentially connecting a plurality of short tubes 5 with caulking pins 6 or the like, as shown in FIG.
A guide wire 12 for bending operation is passed through 3. The neutral axis of the curve is on the center axis of the curved part, so when the curve is curved, the passage of built-in objects becomes shorter on the side closer to the center of curvature, that is, on the inner periphery, and the passage of built-in objects becomes shorter on the side that is far from the center of curvature, that is, on the outer periphery. become longer. This causes the internals to be subjected to compression on the near side and tensile forces on the far side. Therefore, the internal components that are compressed move toward the outer periphery, which has a longer path, or shift toward the operating section. Moreover, the built-in objects under tension try to move toward the inner circumferential side, where the path is shorter, and press other built-in objects located on the inner circumferential side. In particular, hard tubes such as the channel 9 for inserting biopsy tools such as forceps are difficult to bend, so they are tried to maintain a nearly straight state, as shown in Figure 3.
There was a tendency to move in the direction of the arrow and press the optical fiber bundles 7 and 8. Furthermore, even if the built-in objects are located on the same inner circumferential side, the amount of movement of the built-in objects differs depending on the distance from the center line, so that mutual sliding occurs between the built-in objects.

In this way, the optical fiber bundle is subjected to forces such as compression, tension, and pressure. In this case, changing the path of the optical fiber bundle in order to eliminate the compressive force only increases the pressing force against other built-in components, and is not necessarily a useful measure. Therefore, in order to reduce this pressing force, it is most desirable to be able to move the optical fiber bundle in the direction of the operating section 1. However, when the internal items move inside the insertion section A,
Between the moving built-in parts and the pipe wall and other built-in parts,
Usually, there is about 50 to 200 g of friction, so unless you push with enough force to overcome this friction, the internals will not retreat. Further, if the optical fiber bundle is bent or buckled from side to side by the force, the force will not be transmitted and the desired movement will not be achieved.

In the optical fiber bundle with the thin-walled tube 15,
It lacks strength against forces perpendicular to the axial direction, and is so-called too weak, so it may collapse under pressure or buckle when compressed. As a result, the optical fiber bundle is bent within the insertion portion of the curved portion 4, meandering in an S-shape, and the individual optical fibers forming the optical fiber bundle may be broken.

To this end, a method has been tried in the past in which the optical fiber bundle located at the curved portion 4 at the distal end of the insertion portion is sheathed with a thin tube 15 such as a silicon tube, and then covered with a thin spiral tube. However, in this method, the portion of the bending operation wire that protrudes inward from the insertion groove edge 13 may fall into the gap in the helical tube that protects the optical fiber bundle and break the optical fiber. There have also been cases of failures in which the edges of this spiral tube have rubbed against other built-in components, such as tubes 10 and 11 for air and water supply, causing the tubes 10 and 11 to be cut. Furthermore, since the helical tube is easily caught by the end of the short tube 5 or the insertion groove edge 13, the insertion resistance of the optical fiber bundle increases, and when bent, the optical fiber bundles 7 and 8 resist the resistance of the built-in objects and The fiber bundle cannot be moved because it cannot withstand the force of pushing it back toward the operating section. As a result, each time the bending operation is performed, the optical fiber bundle moves as if being gradually pulled toward the tip component 2, and is compressed at the tip bending portion, meandering in an S-shape, reducing the tendency of the optical fiber bundle to break. encouraged.

The present invention was made to solve the above-mentioned problems, and provides an endoscope in which breakage of the optical fiber bundle is reduced without sacrificing the insertability of the endoscope insertion section A. This is what I am trying to do.

Hereinafter, the structure of the present invention will be described in detail according to preferred embodiments shown in the accompanying drawings.

FIG. 1 is a diagram showing the appearance of the endoscope. Reference numeral 1 indicates an operating section, and A indicates an insertion section inserted into a body cavity. The insertion part includes a tip component 2, a curved part 4, and a flexible tube 3.
It consists of As shown in FIG. 2, the structure of the insertion tube of the curved portion 4 is such that short tubes 5 with cut-off side edges are successively connected by caulking pins 6 so as to be freely bendable. Further, inside the curved portion 4, as shown in FIG. 4, there are an optical fiber bundle 7 for image transmission, an optical fiber bundle 8 for illumination, a biopsy tool insertion channel 9, an air supply channel 10, a water supply channel 11, An operating wire 12 and the like for bending the curved portion 4 is inserted therethrough.

As shown in FIG.
4, the middle part of which is covered with a flexible thin-walled tube 15 such as a silicone tube, rubber tube, or plastic tube, and both ends of the tube 15 are fastened to the base 14 with a thread, or Glued.

In the endoscope according to the present invention, in addition to the thin-walled tube 15, the optical fiber bundle is covered with a coating layer of synthetic resin material or synthetic rubber in the portion corresponding to the curved portion 4, and the coating is double-layered only in the curved portion. heavy,
Increase its thickness and strengthen the waist. Such coating methods include dipping in emulsion type synthetic rubber or synthetic resin to form a cross-linked film or coagulated film on the thin-walled tube;
A method such as applying a paste-like synthetic resin and solidifying it by squeezing it to a uniform thickness using a die or the like is used. Further, in this embodiment, the covering layer 16 is partially placed over the thin-walled tube 15 that covers the whole, but conversely, the thin-walled tube 15 that covers the whole may be placed over a partial covering layer 16. . Furthermore, if a surface lubricant such as molybdenum disulfide, silicone, or Teflon is applied to the outer surface of the optical fiber bundle that has been coated as described above, the frictional resistance between the built-in components will be reduced, and the path will not change even during bending operations. On the other hand, since the optical fiber bundle moves smoothly, the optical fiber bundle is not buckled, and defects such as those caused by gradual bending into an S-shape can be prevented. Application of this lubricant is also effective in other parts where friction occurs between built-in parts, but
It is particularly effective in curved portions that have large curvatures, and its effects become even greater when used in conjunction with the above-mentioned coating.

According to the endoscope according to the present invention having the above configuration, the tube 15 that is sheathed over the entire length of the optical fiber bundles 7 and 8 is thin-walled, and
8, only the portion corresponding to the curved portion 4 is provided with a coating layer 16 made of synthetic resin or synthetic rubber, so that the outer diameter of most of the body cavity insertion portion A is the same as that of a conventional endoscope insertion portion. The effect on insertability is extremely small. In addition, the stiffness is increased by increasing the wall thickness in some areas, making it resistant to external pressure. It can also withstand pressure from other built-in objects or projections on the edge 13 of the insertion groove of the wire 12, and is resistant to changes in path when bending. It becomes possible to use the compressive force thus generated to convert the optical fiber bundle into a force that pushes the optical fiber bundle toward the operation part 1 side, and no S-shaped meandering occurs at the curved portion 4, and the optical fiber bundle 7, 8 can be prevented from breaking.

In addition, a surface lubricant such as molybdenum disulfide, silicon, Teflon, etc. is applied to the outer surface of the double coating, in this example, the outer surface of the coating 16.
When curved, friction with other built-in objects is reduced, movement within the insertion section A becomes smooth, and changes in path when curved can be followed extremely easily.

As described above, the endoscope according to the present invention successfully achieves the intended purpose and has many practical benefits.

[Brief explanation of the drawing]

Figure 1 is an overview of a general endoscope, Figure 2 is a perspective view showing the configuration of the curved part of the endoscope, and Figure 3 is a cross section showing the state of compression of the optical fiber bundle by the hard tube when curved. 4 is a sectional view showing an example of the arrangement of built-in components, and FIG. 5 is a partially longitudinal side view showing an optical fiber bundle of an endoscope according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Operation part, 4... Curved part, 7... Optical fiber bundle for image transmission, 8... Optical fiber bundle for illumination, 15...
Flexible thin-walled tube, 16...covering layer.

Claims (1)

[Scope of utility model registration request] It has an elongated insertion part A including a distal end component part 2 and a curved part 4 adjacent thereto, and an optical fiber bundle whose outside is covered with a thin tube is arranged inside this insertion part A. The endoscope is characterized in that the outer side of the thin-walled tube covering the optical fiber bundle is overlaid with another synthetic material coating in a portion corresponding to the length of the curved portion 4 in close contact with the thin-walled tube. endoscope.