JPH0697283B2 - Fiber for laser beam transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a laser beam transmission fiber, and more particularly to a laser beam transmission fiber for radiating a laser beam into a lumen organ endoscopically. .

[Prior Art] Radiative endoscopic irradiation of a laser beam to diagnose and treat a lesion such as a tumor in a luminal organ has already been realized by the rapid progress of laser technology. Medical optical transmission fiber used for such laser coagulator,
Usually used through an endoscope. That is, for example, an optical fiber having a laser emitting portion processed at the tip is inserted from the forceps hole of the endoscope hand operation portion, the laser emitting portion at the tip of the optical fiber is exposed from the tip of the endoscope inserting portion, and a tumor etc. The lesion is irradiated with a laser beam to treat the lesion.

However, in general, the optical transmission fiber for laser medical use has an extremely small diameter and a relatively long length, and an optical fiber of such a form is inserted into a forceps hole formed of a small hole in an endoscope insertion portion, and the internal light is transmitted successfully. It is a difficult technique to reach the tip of the endoscope insertion part. In particular, the endoscope insertion portion is bendable so that its tip can be directed to the lesion, and the curved shape of the insertion portion tip makes it difficult to insert the optical fiber. That is, when inserting the optical fiber for laser medical treatment into the forceps hole, the optical transmission fiber cannot be smoothly inserted due to the frictional force between the outer peripheral surface of the optical fiber and the forceps hole, or the optical transmission fiber is forced into the forceps hole. If the optical transmission fiber is inserted into the forceps hole, an accident such as breakage in the forceps hole may occur.

Against this background, Japanese Patent Application No. 59-236070 proposed a fiber for transmitting a laser beam in which a coil spring is wound around the outer circumference of the optical fiber. This laser beam transmitting fiber can be easily inserted into a forceps hole or the like of an endoscope, and a certain effect can be obtained in that insertion / removal and replacement of a laser probe are facilitated.
However, since the optical fiber is generally wound around a coil in the manufacturing process, the optical fiber itself has a winding tendency. That is, a fiber for a laser probe is usually required to have a length of 2 to 3 m, but if the optical fiber is curved due to the curl when wound in a coil, the coiled spring is wound around the fiber. However, the followability of the fiber deteriorates. For example, to turn the fiber tip 90 degrees,
When the rear end of the fiber is rotated 90 °, the tip of the fiber is rotated more than necessary due to this curl (180 ° later), and there is a problem that the desired site cannot be treated.

Then, as a fiber for solving such a problem, a fiber for laser beam transmission has been proposed in which a coil-shaped spring is wound around the outer periphery of an optical fiber and the coil-shaped spring is fixed to the optical fiber at a predetermined portion. In particular, by fixing the coil-shaped spring to the optical fiber at at least two positions on both ends, the rotational force of the coil-shaped spring can be sufficiently transmitted to the optical fiber. Further, in order to improve the followability, it is desirable that the coiled spring wound around the optical fiber has a hardness that does not hinder the insertion of the coiled spring into the curved endoscope,
Therefore, there is a method of increasing the diameter of the wire of the spring, but this increases the outer diameter of the fiber, which makes it difficult to insert the wire into an endoscope forceps hole having a diameter as small as about 3 mm.
Therefore, in this laser beam transmitting fiber, a thin spring element wire is densely wound around the outer peripheral portion of the optical fiber so as to have an appropriate hardness to improve the followability. For example, a spring wire having a diameter of 0.6 mm is tightly wound with an inner diameter of 1.05 mm to form an outer diameter of 2.25 mm and a fiber that can be easily inserted into an endoscope.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, when the fiber for laser beam transmission is bent, an excessive force is applied to the optical fiber, and the optical fiber is broken or the coiled spring and the optical fiber are fixed to each other. May cause a shift in. This will be described with reference to the explanatory view of FIG.

A portion having a length l of a laser beam transmission fiber in which a coiled spring 72 is densely wound around an outer peripheral portion of an optical fiber 71 is bent at an angle θ with a bending diameter D. At this time, since the coiled spring 72 is tightly wound, even if the length l remains inside the bend, the coiled spring 72 remains outside.
72 pitch spreads and becomes longer. Further, since the optical fiber 71 is fixed at both ends of the coil-shaped spring 72, a tensile force is applied to the optical fiber 71 to extend it.

Here, the length of the optical fiber 71 at this bent portion is l
If + Δl and the average winding diameter of the coiled spring 72 are dp, then l + Δl = (D + dp) θ / 2 (1)

On the other hand, since the inner length l is expressed as l = Dθ / 2 (2), the elongation Δl of the optical fiber 71 can be calculated from these equations (1) and (2) as Δl = dpθ / 2 (3). Becomes

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

ε = Δl / l = dp / D That is, for example, the average winding diameter dp of the coiled spring is
When the bending diameter D is 1.65 mm and the bending diameter D is 100 mm, a very large elongation strain ε of 1.65% occurs in the optical fiber 71, resulting in the risk of optical fiber breakage.

Further, the force P that can completely fix the coil-shaped spring and the optical fiber at the fixed portion is P = πdc ² Eε / 4 (4) where dc is the cladding diameter of the optical fiber and E is the Young's modulus of the silica glass. ). Therefore, for example, clad diameter dc = 600 μm,
If Young's modulus E = 7,000 Kg / mm ² and elongation strain ε = 1.65%,
According to the equation (4), P = 32 kg, and an extremely large fixing force is required.

Further, as is well known, an optical fiber is usually provided with a plastic coating on the outer peripheral portion of a quartz fiber element wire, and in many cases, they are not completely fixed but simply adhered. Therefore, the coil spring and the optical fiber are fixed to each other through the plastic layer coated on the optical fiber element wire. Even if the coil spring is completely fixed to the plastic coating, the plastic coating and the optical fiber element are not fixed. There is a risk of slippage between the lines. If such a slip occurs, the optical fiber strand will dent inside the plastic coating at the laser beam emitting end or the connector for laser beam incidence, and the standard will be applied when the laser beam is guided. Not only will the characteristics not be exhibited, but the laser beam will be emitted in an unexpected direction, which will be a very dangerous state. Also, if the optical fiber strand slips between the plastic coating and enters the inside of the coiled spring in this way, the adhesion force of the coiled spring is canceled by the repulsive force of the optical fiber strand, As a result, the followability deteriorates.

Thus, the 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 which is excellent in followability and does not impair its safety and reliability even when it is inserted into an endoscope and bent. To provide.

[Means for Solving the Problems] In order to achieve the above object, the fiber for laser beam transmission of the present invention comprises an optical fiber having a side-emission laser knife portion formed of an inclined surface at the tip thereof, which is provided at the end of an endoscope. Insert it into the endoscope insertion part from the forceps hole on the operation part side, and extend the side-firing laser scalpel part at the tip of the optical fiber to the tip of the insertion part of the endoscope through the curved part on the tip side of the endoscope insertion part. In the laser beam transmission fiber used as a coil, a coiled spring is wound around the outer circumference of the optical fiber of the irradiation probe located from the rear end side of the curved part of the endoscope insertion part to the vicinity of the side-emission laser knife part at the tip. The coiled spring located on the rear end side of the curved portion, is fixed to the outer periphery of the optical fiber, and the other end of the coiled spring located at the tip of the insertion part is rotated with respect to the optical fiber. Regulation In addition, it is externally fitted so as to be movable in the longitudinal direction.

[Operation] With such a configuration, when the fiber for laser beam transmission is inserted from the forceps hole of the manual operation section of the endoscope and extended from the tip of the insertion section, the coil-shaped spring By moving the other end along the optical fiber, it is possible to prevent the optical fiber from rotating and prevent an excessive force from being applied to the optical fiber. Further, in order to match the emission direction of the side-faced laser scalpel portion composed of the inclined surface, the rotational force applied to the coil-shaped spring that rotates the optical fiber is easily transmitted to the other end of the coil-shaped spring, and the followability is improved. Therefore, the emission direction of the laser beam of the side-illuminating laser knife portion can be reliably directed to a desired direction.

The coiled spring is composed of a small-diameter spring arranged on the laser beam emitting end side of the optical fiber and a large-diameter spring arranged on the other end side of the optical fiber, that is, on the hand operating section side, and If fixed to the outer peripheral part of the optical fiber near the connection part, the flexibility of the small diameter spring further improves the followability in the vicinity of the laser beam emission end and due to the hardness of the large diameter spring Operability at the time of insertion into the mirror and rotation is improved.

[Embodiment] A preferred embodiment of the fiber for laser beam transmission according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 3 shows an endoscope which is generally used, and the endoscope is provided at a hand operation part 2 and is provided so as to be connected to the hand operation part 2 and can be inserted into a deep part such as a body. It is composed of a flexible insertion portion 4, a hand operation portion 2, and a connecting portion 6 that connects the light source and other control devices incorporating various control mechanisms necessary for this endoscope. The hand-side operation unit 2 is provided with an eyepiece 2A including an eyepiece on the upper portion thereof, and an air / water operation button 2B, a suction operation button 2C, and a forceps insertion port are provided on the front surface thereof.
2D is provided. A laser beam transmission fiber (hereinafter referred to as an irradiation probe) 1 having a laser emitting portion formed at its tip is usually inserted through a forceps insertion opening 2D, and a hand operation portion 2,
It passes through the insertion portion 4 and is exposed from the tip of the insertion portion 4. The insertion portion 4 includes a curved portion 4A and a flexible portion 4B that supports the curved portion 4A.

The irradiation probe 1 is coupled to a well-known laser light source device (not shown) and transmits a laser beam to its emission end. The irradiation probe 1 is, for example, a quartz fiber composed of a core fiber and a clad layer as is well known, and the laser beam is transmitted through the probe while repeating total reflection. It goes without saying that the irradiation probe 1 can be used as it is, but in many cases, it is used endoscopically in order to process a luminal organ of a living body without laparotomy. That is, after inserting the bending portion 4A of the endoscope insertion portion 4 which is known per se into the target lumen, through the insertion passage (shown by the insertion opening 2D) of the treatment tool such as forceps usually provided in the endoscope. The irradiation probe 1 is inserted into the lumen. The emission end 1A of the irradiation probe 1 can adjust the irradiation direction together with the observation field of view by the bending adjustment knob 2E of the endoscope together with the bending portion 4A of the endoscope insertion portion 4.

The structure of the irradiation end 1A of the irradiation probe 1 will be described with reference to FIGS.

The fiber element wire 11 used in the irradiation probe 1 of the present invention is a glass or plastic optical transmission fiber element wire composed of a core and a clad, which have conventionally known different refractive indexes, and in the case of the present embodiment, the core. Diameter 400μ
A quartz fiber element wire having an m and an outer diameter of the cladding layer of 600 μm is used, and the diameter and the outer diameter can be selected according to the intended use form. In the figure, the irradiation probe 1 is provided with a coating layer having a two-layer structure that is coated over the entire length of the fiber strand. The first coating layer 12 is referred to as a primary coating layer and is therefore a coating layer such as silicon. The second coating layer 13 is a jacket tube such as a nylon tube. The first and second coating layers 12 and 13 do not have a direct effect on the optical transmission, but rather cause cracks or the like in the fiber element wire and further prevent breakage of the fiber element wire 11. .

The side-emitting laser mace portion, which is the emitting end of the fiber element wire 11, is an inclined surface of approximately 35 ° to 40 ° with respect to the center line of the fiber element wire 11.
14 and is polished to an optically smooth surface.
In this way, the fiber strand 11 having the inclined surface 14 formed at the tip
The first and second coating layers 12 and 13 are peeled off over a length including the tip thereof. This fiber strand 11
A transparent quartz hollow cylindrical body 15 having a circular cross section with one end closed in a substantially hemispherical shape is mounted so as to fit into the second coating layer 13 so as to cover the side-lasing laser knife portion. It is desirable that the contact portion between these coatings and the cylindrical body be bonded with an adhesive or the like. As shown in FIG. 6, the cylindrical body 15 is formed with flat surface portions 15A and 15B which are substantially parallel to each other.

A heat-shrinkable tube 17 is fitted to the outer peripheral portions of the cylindrical body 15 and the second coating layer 13 so as to cover them, and is tightly protected by a heat-shrinking action. Although there is a step at the joint between the flat surface portions 15A and 15B of the cylindrical body 15, these portions are tightly tightened together due to the contracting action of the heat-shrinkable tube 17.

An antireflection coating film is formed on the flat surface portion 15A of the cylindrical body 15, and a reflection coating film is formed on the flat surface portion 15B.

Explaining the case where 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 from the laser knife portion, the laser beam totally reflects the fiber element wire 11 as is well known. The laser beam L is radiated in the forward direction of about 60 ° to 75 ° as shown in FIG. 5, after being propagated repeatedly, totally reflected by the inclined surface 14, transmitted through the transparent cylinder 15 including the flat surface portion 15A. The flat portion 15A is configured so that generation of a reflected beam is prevented by the applied antireflection coating film, while reflected beams at other interfaces are configured not to be transmitted by the action of the reflective coating film applied to the flat portion 15B. ing.

FIG. 1 shows a fiber for transmitting a laser beam according to the present invention.
The exterior structure of 19 coiled springs is shown. As shown in FIG. 1, a thin coil spring 20 having a small wire diameter and a large coil spring 22 having a large wire diameter are continuously wound around the outer circumference of the fiber 19. The coil springs 20 and 22 are made of high tensile strength steel wire, piano wire, phosphor bronze spring material, hard copper wire, stainless steel spring material, or the like. Particularly, the stainless steel spring material is advantageous in that it has an anticorrosive function.

The small-diameter coiled spring 20 is formed, for example, to have a wire diameter of 0.4 mm and a coil inner diameter of 1.20 mm, and the length thereof is substantially the length of the curved portion 4A (approximately 150 mm). Small coil spring 20
The tip portion 20A of the is externally fitted to the rear end portion of the heat-shrinkable tube 17. In this case, when the tip end portion 20A of the coiled spring 20 is separated from the heat shrinkable tube 17 and directly fitted onto the outer circumference of the fiber 19, the protection of the fiber 19 becomes insufficient, and the appearance is also inferior. Reduce. Further, the tip of the spring 20 is only externally fitted to the tube 17 and is not fixed, and as a result, it is possible to reduce the influence of curl when the probe is rotated.

A large-diameter coil spring 22 is wound around the fiber 19 so as to be connected to the small-diameter coil spring 20. The large-diameter coiled spring 22 is formed with a wire diameter of 0.6 mm and a coil inner diameter of 1.05 mm, and is arranged over the flexible portion 4B of the endoscope insertion portion 4. The thin coil-shaped spring 20 and the large-diameter coil-shaped spring 22 have different wire diameters because the spring 20 is located in the bending portion 4A, so it is necessary to easily follow the bending operation of the bending portion 4A. In order to reduce the influence of the winding tendency of the fiber 19, on the other hand, since the spring 22 is located in the flexible part 4B, it does not need to be so bendable. This is because it is convenient during rotation. The tip 22A of the large-diameter coiled spring 22
Is joined to the rear end portion 20B of the small-diameter coil spring 20 to form a joint portion 21. Examples of this joining method include brazing joining after butting, brazing joining after external fitting of the connection sleeve, joining by resin (nylon) molding, laser welding, and the like.

Also, the large-diameter coiled spring 22 is
At 23, it is fixed to the fiber 19 by the resin 23. The vicinity 22B of the tip of the large-diameter coiled spring 22 (one end of the coiled spring composed of the large-diameter coiled spring 22 and the small-diameter coiled spring 20 from the tip 22A to the vicinity 22B of the tip) It is designed to be positioned on the rear end side of the curved portion 4A when it is inserted from the forceps hole 2D of the endoscope shown in FIG. A bonding method, a resin molding method, or the like is used as the fixing method. However, a molding method using a resin of the same type as the second coating layer 13 of the fiber 19, such as nylon, can provide a strong fixing force in a short time. This is advantageous because it can. Further, at this fixing portion, as shown in FIG. 1, by widening the winding pitch of the large-diameter coil spring 22 to promote the inflow of the resin 23, the fixing property is further improved.

On the other hand, the rear end portion 22C of the large-diameter coiled spring 22 is fitted in the guide sleeve 24 and is fixedly adhered thereto. Further, as shown in FIG. 2, the fiber 19 has a core 2 within a slit 24A provided in a longitudinal direction of a guide sleeve 24.
It is glued and fixed to 5. The core 25 is provided movably in the slit 24A in the longitudinal direction. Further, a Teflon (or nylon) tube 26 is fitted on the rear end portion 24B of the guide sleeve 24. The guide sleeve 24 and the core 25 may be made of stainless steel, aluminum alloy, resin, or the like. A connector to a laser light source (not shown) is provided at the rear end of the fiber 19.

The operation of the fiber for laser beam transmission according to the present invention configured as described above is as follows. First, as shown in FIG. 1, the probe 1 having the coil springs 20 and 22 wound around the outer periphery thereof is inserted from the forceps hole 2D of the endoscope hand operation portion 2 shown in FIG. In this case, in the conventional fiber, the forceps hole and the outer peripheral surface of the fiber were in line contact,
The probe 1 according to the present embodiment has a coiled spring on the outer circumference.
Since 20, 22 are wound, the contact between the probe 1 and the forceps hole is in a point contact relationship. Therefore, the frictional force at the time of insertion of the probe 1 is reduced, and the probe 1 can be smoothly inserted even in the insertion portion 4 having a curved tip. Further, even if the side laser scalpel part at the tip of the fiber is damaged and the like necessitates replacement, it can be pulled out easily, so that the replacement can be performed quickly. Furthermore, the outer circumference of the probe 1 is spring 20,2.
Since it is protected by 2, the occurrence of breakage accidents is less than in the case of a fiber-only irradiation probe.

Further, the fiber 19 and the large-diameter coil-shaped spring 22 are fixed to each other near the tip 22B of the spring 22, and near the rear end 22C of the guide sleeve 24 and the core 25.
Since they are configured so as to move in the longitudinal direction with respect to each other but not to rotate, the rotational force applied to the spring 22 is sufficiently transmitted to the fiber 19 and the followability at the tip of the probe 1 is improved. As a result, it is possible to easily orient the side-illuminating laser knife portion at the tip of the probe 1 in a desired direction. Further, since the springs 20 and 22 have a sufficiently large bending rigidity with respect to the fiber 19, even if the fiber 19 has a winding tendency, its influence is reduced.

Further, even if the springs 20 and 22 are bent and an axial force is applied to the fiber 19 at the time of storage, disinfection, or insertion into the endoscope, the fiber 19 and the spring 22 are separated from each other at the rear end of the spring 22. Since the fiber 19 is covered with the coil-shaped spring 20 because the tip 20A, which is the other end of the small-diameter coil-shaped spring 20, moves toward the side-emitting laser knife portion because of relative movement, the fiber 19 The force applied to can be reduced.

Furthermore, since the spring is composed of the small-diameter coil-shaped spring 20 and the large-diameter coil-shaped spring 22,
It is possible to sufficiently follow the bending operation of the bending portion 4A and to give a sufficient insertion force when inserting the probe 1.

Although the wire diameter is changed to change the flexibility of the spring in the above embodiment, the flexibility may be changed by changing the material and the winding state.

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

(1) Since the coiled spring is wound around the outer circumference of the optical fiber, it can be easily inserted into the forceps hole or the like of the endoscope, and the insertion / removal of the irradiation probe and the replacement thereof can be extremely facilitated.

(2) The rotational force applied to the coiled spring is easily transmitted to the optical fiber, and the followability is remarkably improved. That is, it is possible to easily and surely direct the side-scattering laser knife portion in a desired direction.

(3) Even if the optical fiber is bent during storage, disinfection, insertion into the endoscope, etc., excessive force is not applied to the optical fiber, and safety is improved.

[Brief description of drawings]

1 is a block diagram of a fiber for transmitting a laser beam according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 shows the entire structure of an endoscope. FIG. 4 is a perspective view, FIG. 4 is a vertical cross-sectional view showing the tip structure of the embodiment, FIGS. 5 and 6 are cross-sectional views taken along the line V-V and line VI-VI in FIG. 4, respectively. FIG. 7 is an explanatory diagram showing the problems of the prior art. In the figure, 1 is a fiber for transmitting a laser beam, 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.

Front page continuation (72) Inventor Hiroshi Shibamoto 1-324 Uetakecho, Omiya City, Saitama Prefecture Fuji Photo Optical Co., Ltd. (72) Hideyuki Takashima 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Cable Electric Wire Laboratory Co., Ltd. (72) Inventor Koichi Abe 5-1-1 Hidakacho, Hitachi City, Ibaraki Hitachi Cable Electric Wire Co., Ltd. (72) Inventor Makoto Horie 5-chome Hidakacho, Hitachi City, Ibaraki Prefecture No. 1 in the Electric Cable Research Laboratory, Hitachi Cable, Ltd. (56) Bibliography Sho 59-90902 (JP, U)

Claims (2)

[Claims] Claim: What is claimed is: 1. An optical fiber having a side-faced laser scalpel portion formed of an inclined surface at its tip is inserted into the endoscope insertion portion from a forceps hole on the side of the hand operation portion of the endoscope, and the endoscope is inserted. In the laser beam transmission fiber that is used by extending the side-emitting laser scalpel part of the optical fiber tip to the tip of the insertion part of the endoscope through the bending part on the tip side of the endoscope, the rear end of the bending part of the endoscope insertion part The outer circumference of the optical fiber located from the side to the vicinity of the side-emitting laser knife portion of the tip, a coiled spring is wound, one end of the coiled spring located on the rear end side of the curved portion of the optical fiber Fixed on the outer periphery,
A fiber for laser beam transmission, characterized in that the other end of the coil-shaped spring located at the tip of the insertion part is externally fitted to the optical fiber so as to restrict rotation and move in the longitudinal direction thereof. 2. A small-diameter coil-shaped spring arranged in a curved portion of an insertion portion of the optical fiber on the side of a laser scalpel for side emission and a large-diameter arranged in a rear end side of the curved portion. The fiber for transmitting a laser beam according to claim 1, characterized in that the fiber comprises a coiled spring and is connected to each other.