JPS62210404A - Fiber for laser beam transmission - Google Patents

Abstract

PURPOSE:To obtain superior follow-up performance and to prevent safety and reliability from being spoiled even if an optical fiber is inserted into an endoscope and bent by fixing one end of a coiled spring at its outer peripheral part nearby a laser beam projection end part, and controlling the rotation of the other end part around the optical fiber and also providing it movable in its lengthwise direction. CONSTITUTION:When a probe 1 is inserted into the forceps hole 2D of an endoscope hand operation part 2, the probe 1 has coiled springs 20 and 22 wound around its outer periphery, so it comes into spot contact with the forceps hole 2D. Consequently, the probe 1 is reduced in frictional force during the insertion and inserted smoothly even into an insertion part 4 whose tip is curved, and further extracted with ease when it needs to be replaced, thereby reducing breakage accidents. Further, the fiber 19 and large-diameter coiled spring 22 are fixed nearby 22B the tip part of the spring 22 and prevented from rotating although they move lengthwise mutually through a guide sleeve 24 and a core 25 nearby the rear end part 22C. Consequently, turning force applied to the spring 22 is transmitted to the fiber 19 sufficiently and the follow-up performance at the tip part of the probe 1 is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fiber for transmitting a laser beam, and particularly relates to a fiber for transmitting a laser beam for radially endoscopically irradiating a laser beam into a luminal organ. Regarding.

[Prior Art 1] Diagnosis and treatment of lesions such as tumors in hollow organs by irradiating laser beams endoscopically has already been realized due to rapid advances in laser technology. Medical optical transmission fibers used in such laser coagulators, etc.
Usually used through an endoscope. That is, for example, an optical fiber with a laser emitting section at its tip is inserted through the forceps hole of the endoscope's hand control section, and the laser emitting section at the tip of the optical fiber is exposed from the distal end of the endoscope insertion section to remove tumors, etc. The lesion is treated by irradiating the lesion with a laser beam.

However, optical fibers (generally used for laser medical optical transmission) have an extremely small diameter and a relatively long length, and it is possible to successfully insert an optical fiber of this type into a forceps hole consisting of a small hole in an endoscope insertion section. It is extremely difficult to reach the distal end of the endoscope insertion section.

In particular, the endoscope insertion section is curved so that its tip can be directed toward the diseased area, and the curved shape of the insertion section tip makes it difficult to insert the optical fiber. In other words, when inserting a laser medical optical fiber into a forceps hole, the optical transmission fiber may not be inserted smoothly due to the frictional force between the outer peripheral surface of the optical fiber and the forceps hole, or the optical transmission fiber may be forced into the forceps hole. If an attempt is made to insert the fiber into the forceps hole, there is a risk of an accident such as the optical transmission fiber breaking inside the forceps hole.

Against this background, Japanese Patent Application No. 59-236070 proposed a laser beam transmission fiber in which a coiled spring was wound around the outer periphery of the optical fiber. This laser beam transmission fiber can be easily inserted into the forceps hole of an endoscope, and can be used to insert and remove the laser probe.
A certain effect could be achieved in that replacement etc. became easier. However, since optical fibers are generally wound into coils during the manufacturing process, the optical fibers themselves have curls. In other words, the fiber for laser probes usually requires a length of 2 to 3 meters, but if the optical fiber is curved due to the curl when wound into a coil, it may be necessary to wrap a coiled spring around the fiber. Also, the followability of the fiber deteriorates. For example, if the rear end of the fiber is rotated 90° to avoid changing the direction of the fiber tip by 90°,
This curl causes the fiber tip to rotate more than necessary (for example, 180°), resulting in the inconvenience that a desired site cannot be treated.

Therefore, as a fiber to solve this problem, a laser beam transmission fiber has been proposed in which a coiled spring is wound around the outer periphery of the optical fiber and the coiled spring is fixed to the optical fiber at a predetermined portion. In particular, by fixing the coiled spring to the optical fiber at least at two locations at both ends, it has become possible to sufficiently transmit the rotational force of the coiled spring to the optical fiber. In addition, in order to improve followability, it is desirable that the coiled spring wrapped around the optical fiber has a hardness that does not cause problems when inserted into a curved endoscope. There is a way to increase the diameter of the wire, but
In this case, the outer diameter of the fiber becomes thicker, usually about 3am+fi.
! This makes it difficult to insert the endoscope into the small-diameter forceps hole. Therefore, in this laser beam transmission fiber, a thin spring wire is tightly wound around the outer periphery of the optical fiber to give it appropriate hardness and improve followability. For example, a spring wire with a track diameter of 0.6 is
．． The fiber was wound tightly to a length of 0.05 m, and had an outer diameter of 2.25 m, forming a fiber that could be easily inserted into an endoscope.

[Problems to be Solved by the Invention] However, in the conventional example described above, when the laser beam transmission fiber is bent, excessive force is applied to the optical fiber, which may cause the optical fiber to break or become trapped between the coiled spring and the optical fiber. , there is a risk that the foot may become misaligned. This will be explained with reference to the explanatory diagram of FIG.

A portion of the laser beam transmission fiber, in which a coiled spring 72 is tightly wound around the outer periphery of the optical fiber 71, is bent at an angle θ along the bending radius. At this time, since the coiled spring 72 is tightly wound, even if the length J remains the same on the inside of the bend, the pitch of the coiled spring 72 widens and becomes longer on the outside. Further, since the optical fiber 71 is fixed at both ends of the coiled spring 72, a tensile force is applied to the fiber 71 from now on, causing it to be elongated.

Here, the length of the optical fiber 71 at this bent portion is J+ΔA, and the average winding diameter of the coiled spring 72 is dp.
Then, 1+ΔJ? −(D+dP)θ/2 (1).

On the other hand, the inner length J is expressed as 41-Dθ/2 (2), so from these (1) and (9), the elongation Δj of the optical fiber 71 is expressed as Δau dpθ/2... (3) becomes.

Therefore, from equations (2) and (3), the elongation strain ε generated in the optical fiber 17 is expressed as follows.

ε−ΔjJ/fl=dp/D That is, for example, if the average winding diameter dp of a coiled spring is 1.651 m
5. When the bending radius is 11001n, the optical fiber 7
1, a very large elongation strain ε of 1.65% occurs, resulting in a risk of optical fiber breakage.

In addition, the force P that can completely fix the coiled spring and the optical fiber at the fixed part is as follows: P=πdc2Eε/4 (4 ). Therefore, for example, cladding diameter dc = 600 mm,
Young's modulus E = 70007 (g/view 2. Elongation strain ε = 1
．． If it is 65%, P=3289 from equation (4), which requires an extremely large fixing force.

Furthermore, as is well known, optical fibers are usually provided with a plastic coating on the outer periphery of a quartz fiber wire, and these are often simply attached without being completely fixed. Therefore, the coiled spring and the optical fiber are fixed together through the plastic layer coated on the optical fiber cable, and even if the coiled spring is completely fixed to the plastic coating, the plastic coating and the optical fiber There is a risk of slipping between the wires. If such slippage occurs, the optical fiber will sink inside the plastic coating at the laser beam output end or the laser beam input connector, and the laser beam will not meet the specifications when guided. Not only will the expected characteristics not be achieved, but the laser beam will be emitted in an unexpected direction, creating an extremely dangerous situation. Additionally, if the optical fiber slips between the plastic coating and enters the coiled spring, the adhesion force of the coiled spring is canceled out by the repulsive force of the optical fiber, and the As a result, followability deteriorates.

Thus, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a fiber for laser beam transmission that has excellent followability and does not impair its safety and reliability even if it is inserted into an endoscope and bent. Our goal is to provide the following.

[Steps to Solve the Problems] In order to achieve the above object, the laser beam transmission fiber of the present invention has a coiled spring wound around the outer periphery of the optical fiber along its longitudinal direction. In the transmission fiber, one end of the coiled spring is fixed to the outer periphery near the laser beam emitting end of the optical fiber,
The other end is provided to restrict rotation relative to the optical fiber and to be movable in the longitudinal direction.

[Function] With this configuration, the rotational force applied to the coiled spring is easily transmitted to the optical fiber, and followability is improved. Furthermore, when bent, one end of the coiled spring moves in the longitudinal direction of the optical fiber, thereby preventing excessive force from being applied to the optical fiber.

The coiled spring is composed of a small diameter spring placed on the side of the laser beam output end of the optical fiber and a large diameter spring placed on the other end side of the optical fiber, that is, on the hand operation unit side, and both of these springs are arranged on the side of the laser beam output end of the optical fiber. If it is fixed to the outer periphery of the optical fiber near the connection part, the flexibility of the small diameter spring will further improve the followability near the laser beam emitting end, and the hardness of the large diameter spring will improve internal visibility. Improves operability when inserting into the mirror and rotating it.

[Embodiments] Preferred embodiments of the laser beam transmission fiber according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 3 shows a commonly used endoscope, which includes a hand-held operating section 2 and a hand-held operating section 2 that is connected to the hand-held operating section 2 and that can be inserted deep inside the body. It is composed of a flexible insertion section 4 and a connecting section 6 that connects the hand operation section 2 and a control device that incorporates a light source and various other control mechanisms necessary for this endoscope. The hand operation section 2 has an eyepiece section 2A including an eyepiece lens on its upper part, and an air/water supply operation button 2B and a suction operation button 2C on the front side.
1. A forceps insertion port 2D is provided. A laser beam transmission fiber (hereinafter referred to as an irradiation probe) 1 having a laser emitting section formed at its tip is usually inserted through the forceps insertion port 2D, and is connected to the hand operation section 2. It passes through the insertion section 4 and is exposed from the tip of the insertion section 4. The insertion portion 4 is composed of a curved portion 4Δ and a flexible portion 4B that supports the curved portion 4Δ.

The irradiation probe 1 is coupled to a well-known laser light source device (not shown) and transmits a laser beam to its output end. Irradiation block O-
As is well known, the probe 1 is composed of a core fiber and a cladding layer, for example, a quartz fiber, and the laser beam is transmitted through the probe while repeating total reflection. Although it goes without saying that this irradiation probe 1 can be used as is, it is often used endoscopically to treat living body hollow organs and the like without 1711 abdominal surgery. That is, after inserting the curved part 4A of the endoscope insertion part 4, which is known per se, into the target lumen, it is inserted through the insertion passage (indicated by the insertion port 2D) for a treatment tool such as forceps normally provided in the endoscope. The irradiation probe 1 is inserted into the lumen. Output end 1 of irradiation probe 1
A can adjust the observation field and the irradiation direction by the bending part 4A of the endoscope insertion part 4 and the bending adjustment knob 2E of the endoscope.

The structure of the irradiation end 1A of the irradiation probe 1 will be explained based on FIGS. 4 to 6.

Fiber wire 11 used in irradiation probe 1 of the present invention
is a conventionally well-known optical transmission fiber made of glass or plastic composed of a core and a cladding having different refractive indexes, and in this example, the core diameter is 40 mm.
A quartz fiber wire having an outer diameter of 0.01 m and a cladding layer outer diameter of 600 I11 is used, but these diameters and outer diameters can be selected depending on the intended use. In the figure, the irradiation probe 1 is equipped with a two-layered coating layer covering the entire length of the fiber wire. The first coating Ff11112 is called a primary coating layer, and is a coating layer such as silicon, for example. The second jacket B13 is a jacket tube such as a nylon tube. 1st and 2nd coating JI
112 and 13 do not have a direct effect on optical transmission, but rather cause cracks, etc. to occur in the fiber wire;
Furthermore, it is for preventing breakage of the fiber wire 11.

The output end side of the fiber strand 11 is formed as an inclined surface 14 of approximately 358 to 4 G'' with respect to the center line of the fiber strand 11, and is polished to an optically smooth surface. The fiber wire 11 on which the numerals 14 are formed is covered with the first and second coats 1!!11 over a certain length including its tip.
2.13 has been peeled off. This fiber wire 1
A transparent hollow cylindrical body 15 made of quartz having a circular cross section and having one end blocked in a substantially hemispherical shape is attached to the second covering 1 so as to include the exposed portion of the second covering 1.
113 so as to fit therein. It is desirable that the contact portions of these coatings and the cylinder be joined with an adhesive or the like. As shown in FIG. 6, a substantially parallel flat portion 15A faces the cylindrical body 15.

15B is formed.

A heat-shrinkable tube 17 is fitted around the outer periphery of the cylindrical body 15 and the second covering Ji13 so as to cover them, and is tightened and protected by heat-shrinking action. Although there is a step between the flat parts 15A and 15B of the cylindrical body 15, these parts are also tightly tightened together by the shrinking action of the heat shrinkable tube 17.

An anti-reflection coating film is deposited on the flat portion 15A of the cylinder 15, and a reflective coating film is deposited on the flat portion 15B.

When the irradiation probe 1 of the present invention configured as described above is connected to a laser device (not shown) to generate a laser beam,
As is well known, the laser beam propagates through the fiber strand 11 while repeating total reflection, and is totally reflected at the inclined surface 14 to reach the flat section 1.
The laser beam L is transmitted through the transparent cylinder 15 including the cylindrical body 15A and irradiated in a direction approximately 60'' to 75 degrees forward as shown in FIG. Generation of the beam is prevented, and the reflection beam at the universal interface is not transmitted through the action of the reflective coating film applied to the flat portion 15B.

FIG. 1 shows the exterior structure of a coiled spring of a laser beam transmission fiber 19 according to the present invention.

As shown in FIG. 1, a small diameter coiled spring 20 with a small wire diameter and a large diameter coiled spring 22 with a large wire diameter are continuously wound around the outer periphery of the fiber 19. The material of the coiled springs 20 and 22 is high tensile strength steel wire and piano wire.

Phosphor bronze spring material, hard copper wire, stainless steel spring material, etc. are used. In particular, stainless steel spring material is advantageous in that it has anti-MR properties.

The small diameter coiled spring 20 has a wire diameter of 0.4 #I, for example.
, the coil is formed to have an inner diameter L2 (lm) and a length approximately equal to the length of the curved portion 4A, approximately 150M+1. The tip 2OA of the small-diameter coiled spring 2o is fitted onto the rear end of the heat shrinkable tube 17.

In this case, if the tip 2°A of the coiled spring 2o is separated from the heat-shrinkable duplex 17 and fitted directly onto the outer periphery of the fiber 19, the protection of one fiber becomes insufficient.
Moreover, it is inferior in terms of appearance, reducing the commercial value. Further, the tip of the spring 2o is only fitted onto the tube 17 and is not fixed to the tube 17, and as a result, the influence of curling can be reduced when the probe is rotated.

A large diameter coiled spring 22 is connected to the small diameter coiled spring 20 and wound around the fiber 19 . The large diameter coiled spring 22 has a wire diameter of 0.6 m.

The coil is formed to have an inner diameter of 1.05 M and is disposed across the flexible portion 4B of the endoscope insertion portion 4. The reason why the small diameter coiled spring 20 and the large diameter coiled spring 22 have different wire diameters is because the spring 20 is located in the curved portion 4A and therefore needs to easily follow the bending motion of the curved portion 4A. On the other hand, since the spring 22 is located in the soft part 4B, it does not need to have that much curvature; rather, it is better to have a certain degree of hardness when inserting the probe. This is because it is convenient when rotating. The tip portion 22A of the large diameter coiled spring 22 is connected to the rear end portion 20A of the small diameter coiled spring 20.
B is joined to form a joint portion 21. As for this joining method, brazing after butting is joining, and brazing after fitting the connection sleeve on the outside is joining.

There are methods such as joining using a wood WI (nylon) mold or laser welding.

Further, the large diameter coiled spring 22 has a portion near its tip.
At 2B, it is fixed to the fiber 19 with resin 23. Adhesion methods, resin molding methods, etc. are used for fixing, but a molding method using the same type of resin as the second coating 1513 of the fiber 19, such as nylon, can obtain a strong fixing force in a short time. Therefore, it is advantageous.

Furthermore, as shown in FIG. 1, in this fixed portion, the winding pitch of the large-diameter coil spring 22 is increased to promote the inflow of the resin 23, thereby further improving the fixing property.

On the other hand, the rear end portion 220 of the large diameter coiled spring 22 is fitted into the guide sleeve 24 and fixed thereto by adhesive. Further, the fiber 19 is inserted into a slit 24 provided in the guide sleeve 24 in its longitudinal direction as shown in FIG.
It is adhesively fixed to the core 25 inside A. This core 25 is provided so as to be freely movable in the longitudinal direction within the slit 2/IA.

Roughly speaking, a Teflon (or nylon) tube 26 is fitted onto the rear end 24B of the guide sleeve 24. The guide sleeve 24 and core 25 are made of stainless steel or aluminum alloy.

Resin etc. can be used. Further, the rear end of the fiber 19 is provided with a connector to a laser light source (not shown).

The operation of the laser beam transmission fiber according to the present invention configured as described above is as follows. First, as shown in FIG. 1, a probe 1 having coiled springs 20 and 22 wound around its outer periphery is shown in FIG. Insert through the forceps hole 2D of the f1m hand control unit 2. In this case, in the conventional fiber, the forceps hole and the outer peripheral surface of the fiber were in line contact, but the probe 1 according to this embodiment has coiled springs 20 and 22 wound around the outer periphery, so the probe 1
The contact between the hole and the forceps hole is in a point contact relationship. For this reason, probe 1 has an I! ! The drifting force is reduced, and even the insertion portion 4 having a curved tip can be smoothly inserted. Furthermore, even if the laser emitting part at the tip of the fiber becomes damaged and needs to be replaced, it can be easily pulled out and replaced quickly. Furthermore, since the outer periphery of the probe 1 is protected by springs 20 and 22, breakage accidents are less likely to occur compared to a laser probe using only a fiber.

Further, the fiber 19 and the large diameter coiled spring 22 are omitted near the tip end 22B of the spring 22, and the guide sleeve 22 is removed near the rear end 22C.
4 and the core 25, but not rotated, the spring 22
The rotational force applied to the fiber 19 is sufficiently transmitted to the fiber 19, and the followability at the tip of the probe 1 is improved. As a result, the laser emitting part at the tip of the probe 1 can be easily directed in a desired direction. Furthermore, since the springs 20 and 22 have a sufficiently large bending stiffness relative to the fiber 19, 7? Even if the fibers 19 are curled, the effect of the curls is reduced.

Furthermore, even if the springs 20 and 22 are bent and axial force is applied to the fibers 19 during storage, disinfection, or insertion into an endoscope, the fibers 19 and the springs 22 will not connect at the rear end of the springs 22. Due to relative movement,
The force applied to the fiber 19 can be reduced.

Furthermore, since the spring is composed of a small-diameter coiled spring 20 and a large-diameter coiled spring 22, it is possible to sufficiently follow the bending movement of the bending portion 4A, and to apply sufficient insertion force when inserting the probe 1. can be given.

In the above embodiment, the wire diameter was changed to change the flexibility of the spring, but the flexibility may be changed by changing the material or changing the state of one coil.

[Effects of the Invention] As explained above, the laser beam transmission fiber according to the present invention exhibits the following excellent effects.

Since a coiled spring is wrapped around the outer circumference of the optical fiber, it can be easily inserted into the forceps hole of an endoscope, etc.
Insertion and removal of laser probe.

Replacement etc. becomes extremely easy.

■ The rotational force applied to the coiled spring is easily transmitted to the optical fiber (the followability is significantly improved, i.e.,
The fiber tip can be easily and reliably directed in a desired direction.

(3) Storage, disinfection, inside? Even if the optical fiber is bent when inserted into the 121I, excessive force is not applied to the optical fiber, improving safety.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a laser beam transmission fiber according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 shows the overall structure of the endoscope. A perspective view, FIG. 4 is a vertical sectional view showing the tip structure of the embodiment, FIGS. 5 and 6 are a sectional view taken along the line V-V and Vl-Vl in FIG. 4, respectively. FIG. 7 is an explanatory diagram showing problems in the prior art. In the figure, 1 is a laser beam transmission fiber, 19 is a fiber, 20 is a small diameter coiled spring, 22 is a large diameter coiled spring, 24 is a guide sleeve, and 25 is a core.

Claims (2)

[Claims] (1) In a laser beam transmission fiber in which a coiled spring is wound around the outer periphery of the optical fiber along its longitudinal direction, one end of the coiled spring is attached to the outer periphery near the laser beam emitting end of the optical fiber. fixed to,
A fiber for laser beam transmission, characterized in that the other end of the coiled spring is provided to restrict rotation with respect to the optical fiber and to be movable in the longitudinal direction thereof. (2) The coiled spring is composed of a small diameter spring disposed on the laser beam emitting end side of the optical fiber and a large diameter spring disposed on the other end side of the optical fiber, and a connecting portion between the two. 2. The laser beam transmission fiber according to claim 1, wherein the fiber is fixed to the outer periphery of the optical fiber in the vicinity.