JPS625121Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the structure of a flexible tube for an endoscope that is thin, yet highly resistant to torsion and highly flexible. This invention relates to a flexible tube for endoscopy.

Flexible tubes for endoscopes are thin-walled and resistant to twisting.
Moreover, something that is flexible is required. In other words, in order to alleviate patient pain, the outer diameter of the flexible tube must be extremely thin.For example, in the case of a bronchial fiberscope, the outer diameter should be around 6.5 mm in order to secure the airway necessary for the patient's breathing. It is considered a limit. However, by reducing this outer diameter by even 0.1 mm, we can secure a larger airway for the patient, prevent a drop in blood oxygen concentration during endoscopy, and reduce patient pain during insertion. It is necessary to facilitate insertion into the deep parts of the bronchi, which become narrower toward the periphery, to expand the observation range and improve diagnostic ability. In addition, in other gastric fiberscopes, laparoscopes, etc., it is desired to reduce the outer diameter of the flexible tube by even 0.1 mm in order to alleviate patient pain.

In addition, it is necessary to make the inner diameter of the flexible tube as large as possible and increase the number of internal components. By increasing the thickness of the bundle and illuminating the subject to clearly observe details, by increasing the shutter speed to take blur-free photographs, and by increasing the forceps channel to collect large tissue cells.
There is a demand for increased durability by increasing the thickness of the operating wire that bends the tip of the endoscope, increasing the strength of the wire, preventing the wire from elongating, and reducing bending attenuation. For the above-mentioned reasons, a flexible tube for an endoscope is required to have a thin outer diameter and a large inner diameter.

By the way, if the flexible tube is made thinner, although it has excellent flexibility, it not only becomes weak against twisting but also has poor mechanical strength.

As shown in Fig. 1, the structure of a conventional flexible tube uses a coarsely wound metal spiral tube 6 inside to prevent collapse and maintain flexibility, and on top of that, a metal spiral tube 6 is used to prevent the spiral tube 6 from elongating. Knitted pipe 8 made of wire with a circular cross section
and further cover the plastic tube 1 so that it becomes the outer cover of the endoscope and can withstand shrinkage.
The knitted tube 8 and the plastic tube 1 are overlaid on the helical tube 6 by being closely pressed in the radial direction so as to withstand twisting. The knitted pipe 8 has a wall thickness equivalent to two pipes, and a diameter equivalent to four pipes. By the way, the conventional structure used for bronchial fiberscopes has a thickness of 0.08 mm, for example.
A right-handed spiral tube and a left-handed spiral tube made of mm to 0.1 mm plates are combined to form a double layer, and a knitted tube with a diameter of 0.08 mm wire is overlaid on top of the spiral tube. Since it occupies a considerable thickness, it occupies a radial dimension of 0.32t. Furthermore, 0.3mm~0.5
Covered with a plastic tube of mm thickness. Therefore, the spiral tube needs to be thick enough to prevent collapse in the radial direction, and the plastic tube needs to be thick enough to prevent wrinkles from forming when the flexible tube is bent. Thickness is limited. Next, since the knitted tube has a diameter that is four times as large as the wire thickness, it has a large proportion in the flexible tube for endoscopes. Due to the demand for thinner knitted pipes, the wires are too thin and have weak stiffness, making them weak against twisting. The wire may fall into the gap between the tubes and damage the built-in components, or the wire of the knitted tube may break due to the wire being stretched due to repeated bending of the flexible tube, or due to friction with the spiral tube. There was a risk of it being lost. Furthermore, if the material is thin, several wire rods bundled together during the production of knitted tubes may overlap, or during work, only one wire may be pulled and pop out, and the rubber or plastic tube that serves as the outer covering may be applied. Convexities are formed locally on the surface of the flexible tube.

Conventional knitted tube wire is used within conditions that cover the above-mentioned drawbacks as much as possible, and the diameter of the wire is limited to a thinness of 0.08 mm at most for bronchial fiberscopes. The braided tube occupied a diameter of 0.32 mm, four times that of the wire, on the diameter of the flexible tube.

As mentioned above, the present invention provides a flexible tube which has a small diameter, is strong against twisting, and is flexible. Inside the flexible tube 1 are an image transmission fiber optic system 3 that guides an image of a subject from an objective lens 2 to an eyepiece (not shown), and an illumination fiber optic system that irradiates the subject with light from a light source device (not shown). 4 (3rd
) and a channel 5 for forceps insertion (Fig. 3), etc. are built in, and the structure of the flexible tube is such that a coarsely wound spiral tube 6 can be placed over the built-in thing in a single or double layer, and The wire is then covered with a braided tube 8 made of a material 10 (see Fig. 4) made into a flat cross-sectional shape by rolling or slitting, and further made of an elastic polymer material such as rubber or plastic, which becomes the outer covering of the flexible tube. It is coated by a method such as tubing or dipping.

In addition to the above-mentioned structure, the gastric fiberscope is equipped with an air supply tube that inflates the inner wall of the stomach. As a flexible tube for endoscopes, a combination in which a braided tube made of a material with a flat cross section is overturned on a coarsely wound spiral tube, and a coarsely wound spiral tube is further overturned on top of that, or the above-mentioned coarsely wound spiral tube and a flat cross section type. By reversing the combination of the material and the knitted pipe, it is made stronger against torsion.
It can also be made more resistant to expansion and contraction. Similarly, in FIG. 2, there is a curved portion A between the tip metal fitting 7 and the flexible tube for tilting the endoscope tip upward and downward during insertion into a body cavity, and the structure of the curved portion is a bellows tube that can be bent. On top of 9 is a material 10 with a flat cross section according to the present invention.
The knitted tube 8 is covered with a plastic or rubber tube 11 which serves as an outer cover.
has been covered.

The structure of this curved portion is required to prevent the rubber jacket 11 from falling into the gap in the bellows tube 9 and to have a thin wall. However, since the wire of conventional knitted tubes is round, Although a wire diameter of approximately 0.08 mm was still required, by using the flat material of the present invention, it is possible to make the wire thinner than that and reduce the outer diameter of the curved pipe portion.

Note that the knitted tube used for scopes with an outer diameter of about 2 mm, such as renal fiberscopes, requires a thinner material that is even thinner than that used for bronchial fiberscopes, but if the flat material of the present invention is used, it will be stronger. It is even more effective.

Therefore, according to the configuration of the present invention, if a wire with a thickness of 0.08 mm is rolled into a flat shape, for example, to a thickness of 0.03 mm, the width will be approximately 0.17 mm, and the cross-sectional shape will be as shown in Fig. 4, which is different from the conventional wire. Thickness 0.08
Previously, only 0.03 mm thick wire could be used, but by using flat wire, material with a thickness of 0.03 mm can be used. Compared to 0.08 x 4 = 0.32, it becomes 0.03 x 4 = 0.12, and a flexible tube with a margin of 0.2 mm can be created. Therefore, the outer diameter of the flexible tube can be reduced by 0.2 mm.

This means that when compared to a wire with a diameter of 0.03 mm, the cross-sectional area related to tensile strength is approximately 7 times larger, and the moment of inertia related to buckling, deflection, and torsion is approximately 9.6 times larger than that of a wire with a diameter of 0.03 mm. The wire was not strong enough to be used as a structural material for this type of endoscope, but the diameter
The material, which is rolled from 0.08mm wire and made into a flat shape with a thickness of 0.03mm, can be used as a structural material for endoscopes due to its strength, and the wall thickness of flexible tubes using this material can be made thinner.

In addition, since the wire rod is rolled, the corners are rounded as shown in Figure 4, so when the flexible tube is bent, it slips between it and the helical tube or outer skin tube, but there is no catching at this time and it is smooth. It can be bent. Next, in manufacturing, if we take into account the work hardening of the wire rods by rolling them, the springiness will further increase, and when making knitted pipes, the wire rods will stack up against each other, and the single wires will stick out during braiding. It is also easier to handle, as there are fewer protrusions on the finished surface of the exterior coating.

According to the present invention, since a thin-walled knitted tube can be made, a desired thickness can be selected depending on the intended use, and the tube can be used, for example, as an outer covering for an optical fiber bundle to prevent wire breakage. In this case, it is effective to cover the thin tube such as a silicone tube with the flat knitted tube of the present invention as the outer sheath of the optical fiber bundle.

In addition, depending on the thickness of the flexible tube of the endoscope, the number of braided tubes made of flat rolled material can be arbitrarily selected from one tube or multiple tubes knitted at the same time, so that the outer jacket can be coated without changing the wall thickness. This can prevent the tube from falling.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the conventional example, Fig. 2 is an explanatory diagram of the embodiment of the present invention, Fig. 3 is a front view of the tip of Fig. 2, Fig. 4 is a sectional view of the knitted pipe material of the present invention, and Fig. 5 is an explanatory diagram of the conventional example. The figure is an enlarged perspective view showing a part of the braided tube according to the present invention. 1: Flexible tube for endoscope, 2: Objective lens, 3: Image transmission fiber optic system, 4: Fiber optical system for illumination, 5: Channel for forceps insertion, 6: Coarsely wound spiral tube, 7: Tip hardware, 8: Knitted pipe, 9: Bellows pipe.

Claims (1)

[Claims for Utility Model Registration] 1. A strand of wire with a flat cross-section woven over a bellows tube such as a loosely wound spiral tube for protecting internal components such as an image transmission optical fiber bundle, an illumination optical fiber bundle, and a channel for forceps. A flexible tube for an endoscope, which is closely covered with a knitted tube and further covered with an elastic polymeric material such as rubber or plastic. 2. A flexible tube for an endoscope according to Claim 1 of the Utility Model Registration Claim, in which the distal end portion is of a tiltable type.