JPS6324886Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a treatment instrument insertion tube of an endoscope.

In order to insert a treatment instrument such as forceps into an endoscope, a flexible insertion tube forming an insertion channel is disposed within the insertion portion of the endoscope. By the way, if you simply use a plastic tube as the insertion tube, it will easily bend at the waist (a phenomenon in which a part of the tube becomes flattened and breaks at a steep angle), so to prevent this, use one with a thick wall. I have no choice but to adopt it. However, it is necessary to make the outer diameter of the treatment instrument insertion tube of an endoscope as small as possible. Therefore, we have proposed a method for winding a coil around the outer periphery of the treatment instrument insertion tube, which has not yet been published, but is shown in Utility Model Application No. 57-131015 (Japanese Utility Model Application No. 59-36302) filed by the present applicant. According to the method shown in this application, the tube is certainly less likely to buckle. However, in this method, a coil body having an improved cross-sectional shape of the wire is simply wound around the tube. Therefore, when the tube is bent to a large bending angle or a small radius of curvature, a large tensile force is generated on the outer wall of the curved portion and a large compressive force is generated on the inner wall. There was an incident where Tube broke his back. Particularly, when the inner diameter of the tube is large, this phenomenon tends to become noticeable.

This idea was made based on the above circumstances,
The object thereof is to provide a treatment instrument insertion tube for an endoscope in which the tube does not bend at the waist even when the tube is bent at a large angle of curvature.

An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 11 in FIG. 1 is an insertion section of the endoscope, and the proximal end of this insertion section 11 is connected to an operation section (not shown). The insertion section 11 includes a flexible tube section 12 located on the proximal side, a curved tube section 13 connected to the distal end of the flexible tube section 12, and a rigid distal end section connected to the distal end of the curved tube section 13. It consists of 14. The flexible tube section 12 is configured to be bent by external force. Further, the bending tube portion 13 is formed by covering the outer periphery of a bending core 16 in which a plurality of bending pieces 15 are rotatably connected to each other with an outer skin 17. The bending tube section 13 can be forcibly bent by pushing and pulling a plurality of operation wires 18 inserted into the insertion section 11 and having their tips connected to the rigid tip section 14 on the operation section side. ing. A through hole 19 that opens to the outside is formed in the rigid tip portion 14, and other components necessary for the endoscope, such as an objective lens system 21, are provided. moreover,
An image guide fiber 2 is provided inside the insertion section 11.
2 and a treatment instrument insertion tube 23 are inserted therethrough. The tip of the image guide fiber 22 is attached and fixed to the rigid tip portion 14, and is optically connected to the objective lens system 21. Further, the tip of the treatment instrument insertion tube 23 is connected to the through hole 19.
It is attached and fixed to the tip rigid portion 14 so as to communicate with the tip. Further, the proximal end side of the treatment instrument insertion tube 23 is guided to the operation section and connected to a treatment instrument insertion opening (not shown) formed in the operation section. That is, the treatment instrument insertion tube 23 forms an insertion channel 24 through which a treatment instrument 30 (shown in FIG. 4) such as forceps, a catheter, or a high-frequency treatment instrument is inserted into the body cavity. In addition, suction can also be performed using this insertion channel 24.

The treatment instrument insertion tube 23 is constructed as shown in FIG. That is, this treatment instrument insertion tube 23
In this case, the coil body 26 is inserted only into a portion of the outer periphery of a flexible tube 25 made of, for example, a fluorine resin material, which is located approximately inside the curved tube portion 13, and the coil body 26 is inserted into the tube 25. A raised portion 28 is formed by raising a portion of the coil body 26 between the strands 27 radially outward. This raised portion 28 is provided, for example, by being molded simultaneously when the tube 25 is molded. Further, the inner diameter of the tube 25 is d over the entire length,
The wall thickness t of the portion where the coil body 26 is wound is formed to be thinner than the wall thickness t ₁ of the other portion. In other words, the portion with the wall thickness t is formed to have a smaller outer diameter than the portion with the wall thickness _t1 . Furthermore, the coil body 26 has a cross-sectional shape of the wire 27, which is an oval shape with a dimension a in the major axis direction and a dimension b in the minor axis direction, as shown in FIG. By crushing it, it is formed into an elliptical shape with semicircular ends at both ends in the longitudinal direction, and the longitudinal direction is aligned along the axial direction of the tube 25. The coil body 26 is formed by spirally winding this wire 27 at a predetermined pitch p. The inner diameter of the coil body 26 is set to be approximately equal to the outer diameter of the portion of the tube 25 around which the coil body 26 is wound.

In this example, fluororesin is used for the tube 25, d is 1.5 to 3 mm, t is 0.1 to 0.3 mm,
a is 0.2 to 0.8 mm, b is 0.1 to 0.3 mm, p is 1.5 to a
It was tripled. Further, the dimension (p-a), that is, the dimension between the strands 27 of the coil body 26, was set to be larger than twice t and smaller than 5 times t.

According to the above configuration, when the curved tube portion 13 is forcibly bent, the portion of the tube 25 around which the coil body 26 is wound is arranged in the fourth position.
Curve as shown. At this time, the coil body 26 exhibits appropriate rigidity, and this rigidity maintains the entire radial shape of the tube 25 in a circular shape, so that the tube 25 hardly bends at the waist. . Also, when the tube 25 is bent, this tube 25
The ridges 28 on the outside of the curved portion extend to disperse the tensile force applied thereto, and the ridges 28 on the inside are compressed to absorb the compressive force applied thereto. Therefore, even if the tube 25 is bent at a particularly large bending angle, the tube 2
5 has almost no chance of buckling. Moreover, since the dimension between the wires 27 of the coil body 26, that is, (p-a), is set in the range of 2 to 5 times the wall thickness t of the portion of the tube 25 where the coil body 26 is wound, the tube When the wire 25 is bent, adjacent wires 27 in the curved portion are prevented from coming into contact with each other. Therefore, the raised portion 28 on the inside of the curved portion protrudes between the strands 27 and is reliably compressed and deformed, which also prevents the tube 25 from buckling. Furthermore, when the tube 25 is curved and the treatment instrument 30 is inserted, the distal end of the treatment instrument 30 is inserted into the tube 25.
The treatment instrument 3 is guided along the outer inner surface of the curved portion of the curved portion 28, so that the treatment instrument 3
There is no possibility that the 0 will get caught and the insertion will not be carried out smoothly.

Furthermore, since the tube 25 has a wall thickness t thinner at the portion around which the coil body 26 is wound than other portions, the radial outward protrusion of the coil body 26 can be reduced accordingly. In other words, the treatment instrument insertion tube 23
can be made thinner over its entire length.

In addition, in the above embodiment, the strands 2 of the coil body 25
Although the cross-sectional shape of No. 7 is oval, the cross-sectional shape may be rectangular, circular, or the like.

Moreover, the raised portion 28 formed on the tube 25 is
The coil body 26 may be formed over the entire portion into which the coil body 26 is inserted, or may be formed only on a portion thereof. When the raised portion 28 is formed only in one portion, it is effective to form it at a location corresponding to the axial center portion of the curved tube portion 13 where the tube 25 is curved at the largest bending angle.

As described above, the present invention provides a treatment instrument insertion tube in which a coil body is inserted into the outer periphery of at least the portion corresponding to the curved tube portion of the flexible tube. The thickness was made thinner than other parts, and the part of the tube located between the strands was formed into a raised part raised outward in the radial direction. Therefore, when the tube is bent, the ridges located on the outside of the curved portion stretch to disperse the tensile force, and the ridges located on the inside are compressed and absorb the compressive force.
The tube hardly bends due to the above-mentioned tensile force or compressive force, and is particularly effective for tubes with a large inner diameter that generate large tensile force or compressive force when curved. In addition, since the wall thickness of the part where the coil body of the tube is inserted is made thinner than other parts, the outer diameter of the treatment instrument insertion tube is made thinner accordingly, and the insertion part, especially the curved tube part, is made thinner to facilitate insertion. Furthermore, since the coil body is provided only on the outside of the tube, the inner surface of the tube can be easily and reliably cleaned after use.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side sectional view of the endoscope insertion section, Fig. 2 is a side sectional view of the treatment instrument insertion tube, and Fig. 3 is a sectional view of the strands of the coil body. , 4th
The figure is a side sectional view when the treatment instrument insertion tube is curved. 25...tube, 26...coil body, 27...
...Line wire of coil body, 28...Protuberance.

Claims (1)

[Claims for Utility Model Registration] (1) An endoscope in which a coil body is fitted around at least the outer periphery of a flexible tube inserted into an insertion section having a curved tube section, at least in a portion corresponding to the curved tube section. In the treatment instrument insertion tube, the wall thickness of the portion of the tube into which the coil body is inserted is made thinner than other portions, and the portion of the tube located between the wires of the coil body is made radially outward. A treatment instrument insertion tube for an endoscope, characterized in that the treatment instrument insertion tube is formed in a raised part. (2) Utility model registration claim 1, characterized in that the raised portion is formed on at least a part of the portion of the flexible tube into which the coil body is inserted.
Endoscope treatment instrument insertion tube as described in section. (3) Utility model registration claim 1, characterized in that the distance between the strands of the coil body is between two times and five times the wall thickness of the portion of the tube into which the coil body is inserted. Endoscope treatment instrument insertion tube as described in section. (4) The treatment instrument insertion tube for an endoscope according to claim 1, wherein the cross-sectional shape of the wire of the coil body is approximately oval or rectangular.