JPS6164242A - Laser beam incident fiber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a fiber for laser beam side emission, and particularly to a fiber for side emission of a laser beam for laterally irradiating a laser beam into a hollow organ. related to optical fibers.

[Background of the invention]

Rapid progress in laser technology has made it possible to diagnose and treat lesions such as tumors in hollow organs by irradiating transendoscopic laser beams. A fiber for transmitting a laser beam endoscopically into a living body's hollow organ and irradiating it to a lesion is a direct-emitting fiber that has an output end face perpendicular to its length. When this direct-fiber type fiber is used for radial endoscopy, the endoscope can be
The laser beam may not be irradiated to the lesion even if it is visible within the observation field of the endoscope, or the lesion itself or its surroundings may be restricted or not allowed to move depending on the local area. A problem arises in that the lesion cannot be completely irradiated due to the deformation of the lesion.

In addition, when used with a direct-projection endoscope, the laser beam irradiation fiber is led out from the endoscope almost parallel to the optical axis of the endoscope's objective lens, so the laser beam is tangential to the lesion. Since the irradiation is performed in the same direction, it is inevitable that the proximal part is irradiated with too strong energy or the distal part is irradiated with insufficient energy, resulting in uneven irradiation, and the irradiation energy distribution in the lesion area is not uniform. Depending on the mode of deformation of the lesion, some parts may remain that are not irradiated at all, and the non-uniformity of the irradiation energy distribution is a major problem from a clinical standpoint in laser diagnosis and treatment of tumors and the like.

Uniform distribution of irradiation energy is achieved by irradiating the lesion directly.

For this purpose, attempts have been made to irradiate the lesion with a laser beam from the front using a so-called strabismus-looking endoscope or a side-viewing endoscope; The observation field of the mirror is significantly narrower than that of a direct-viewing endoscope, and therefore it is not always easy to explore and observe the lesion, and it is not always easy to treat when used in combination with a fiber for laser beam irradiation. It is not an effective method. In addition, when used in conjunction with a side-viewing endoscope, the distal end side must be bent significantly in order to derive the irradiation fiber, and with the current material strength of the fiber wire, there is a high possibility of breakage, and the broken part is It remains in the human body and is extremely dangerous.

A patent application has already been filed by the applicant for a laser beam side-emitting fiber that makes it possible to irradiate a laser beam from the front to a lesion in a hollow organ, taking advantage of the observation characteristics and advantages of a direct-emitting endoscope. This is proposed in the specification of Sho 58-161585. The fiber for laser beam side emission proposed in JP-A No. 58-161585 has its output end formed as a reflective surface inclined at approximately 45 degrees with respect to the center line of the fiber, so that the laser beam transmitted within the fiber is The optical path of approximately 90
It is configured so that it can be reflected and bent so that it can be emitted laterally from the side surface of the fiber. A reflective film is formed on the outer surface of the inclined reflective surface to increase the reflection efficiency. Although such fibers for side-emitting laser beams were developed to achieve the initial purpose of irradiating the inner wall of hollow organs, they have the following practical drawbacks.

First, a reflective film deposited on the inclined reflective surface at the output end of the fiber cannot provide a sufficiently high reflectance, resulting in large energy loss. As a result, the reflective film deteriorates and burns out. This happens very easily when the output energy of the laser increases, and results in the tip of the fiber itself being burned out. In addition, since such laser beam irradiation fibers are used inside hollow organs, foreign substances such as blood and other body fluids are likely to adhere to the reflective film layer formed on the tip. If it gets attached, it will burn out at a lower level of output energy.

On the other hand, a fiber for medical laser beam irradiation requires a length of about 1.5 m to several meters, and a reflective layer is applied only to a small area at the tip of such a long fiber by vacuum deposition, for example. It is a difficult task to form by
Moreover, the entire fiber strand is heated to a high temperature for this purpose, and the primary coating layer is deteriorated and damaged, making the fiber strand more likely to break.

Second, since the end of the fiber on the output side is formed into an acute angle, it is easily broken. If a fiber for laser beam irradiation is introduced endoscopically into a hollow organ, it is easily damaged. Breakage of the acute-angled portion at the end of the output side of the fiber wire causes partial peeling of the reflective film layer formed on the reflective surface, and burnout occurs from the peeled portion.

Furthermore, the sharp-angled portion at the end of the output side of the fiber wire can easily damage the inner wall of the hollow organ, which is extremely dangerous.

(Object of the Invention) The present invention has been made in view of the above circumstances, and provides a laser beam side emitting device which has an output end with high reflectance without forming a reflective film layer on the laser beam reflecting surface and which does not burn out. The purpose is to propose fiber.

A further object of the present invention is to propose a laser beam side-emitting fiber whose laser beam emitting end does not damage the inner wall of the lumen (2).

[Summary of the invention]

According to the present invention, the laser beam side-emitting fiber is a transparent tube whose output end is formed into an inclined surface at approximately 45 degrees with respect to the center line of the fiber cotton, and whose one end is closed in a shape that does not include an acute angle part. Since the fiber is fitted with a body and an air layer is formed behind the sloped surface of the output end of the fiber, high reflectance can be achieved without the need to deposit a reflective layer on the sloped surface as in the conventional method. At the same time, it is possible to easily prevent burnout of the fiber output end and damage to the inner wall of the hollow organ.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a laser beam side emission fiber according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of an embodiment of a laser beam side-emitting fiber according to the present invention, and FIG. 2 is a cross-sectional view taken along line -n in FIG. The fiber wire 11 is a well-known fiber wire for optical transmission made of glass or plastic and composed of a core and a cladding having different refractive indexes, and in this embodiment, the core diameter is 400 μm and the cladding layer outer diameter is 400 μm. It is a 650μ quartz fiber. A primary coating layer 12 made of a synthetic resin material is formed on the fiber wire 11 over its entire length. Fiber element' on which this primary coating layer 12 is formed! The rfAll is further protected by a flexible protective jacket tube 13, which prevents the formation of crud etc. on the fiber strand 11 and prevents the fiber strand 11 from folding.

This protective jacket tube 13 is preferably made of vinyl resin material.
Synthetic resin materials such as nylon and Teflon are used. In order to bend the transmitted laser beam from the fiber in its length direction and emit it, the end of the fiber strand 11 is formed as an inclined plane 14 at approximately 45 degrees with respect to the center line of the fiber strand 11. The surface is polished to a smooth surface. In this way, the tip is tilted at an approximately 45 degree plane 14.
The fiber wire 11 formed in the above is coated with the primary coating layer I2 and the protective jacket tube 1 over a certain length including its tip.
Part of 3 has been removed. Fiber wire 1 from which this primary coating layer and protective jacket tube 13 have been peeled off and removed
The output end of the tube 1 is fitted into a transparent cylindrical body 15 having a circular cross section with one end closed in a hemispherical shape, and is firmly and airtightly adhered with an epoxy adhesive 16. The inclined plane 14 of the fiber strand 11 is arranged so that an air layer 17 is formed between the inner surface of the cylindrical body 15 and the inclined plane 14 of the fiber strand 11 within the transparent cylindrical body 15.
is located. A stepped portion 17 is formed around the entire circumference of the open end side of the transparent cylinder 15, and this stepped portion 18 is made of a flexible material such as Teflon to protect and reinforce the fiber strand 11 over almost its entire length. The distal end portion of the reinforcing tube 19 is fixed by adhesion or by heating to enlarge the inner diameter and then cooling and shrinking. This reinforcing tube 19 has a gap 2 having a circular cross section over the entire length between this inner peripheral surface and the protective jacket tube 13 of the fiber strand 11.
The transparent cylinder 15 is provided with an inner diameter sufficient to form 0 and an outer shape approximately equal to the outer shape of the transparent cylinder 15.

A groove 20 is formed in a part of the transparent cylindrical body 15, which communicates with the void 21 when the tip of the fiber wire 11 and the tip of the reinforcing tube 19 are fitted into the open end of the cylindrical body 15. .

In the laser beam side emission fiber with the above structure,
The laser beam transmitted through the fiber wire 11 is totally reflected by the approximately 45-degree inclined surface in contact with the air layer 17, bends the optical path at right angles, and is emitted from the side surface of the transparent cylinder 15. At the same time, pressurized air is supplied to the gap 21 provided so as to cover the entire length of the outer periphery of the fiber strand 11.
The laser beam is ejected to the outside through a groove 20 formed in the transparent cylinder 15 so as to communicate with the transparent cylinder 15, and cools a portion of the transparent cylinder 15, that is, a peripheral portion including the laser beam emitting part, thereby preventing heat generation.

As is clear from the above embodiments, the fiber for laser beam side emission according to the present invention reflectively bends the optical path of the laser beam transmitted through the fiber cotton by approximately 90 degrees, so that the fiber for side emission of the laser beam according to the present invention A transparent cylinder with one end closed is fitted to the output side tip of the fiber cotton to form a reflective surface for emitting light to a non-contact surface and an air layer in contact with f to form a total reflection surface. Therefore, there is no need to apply a conventional reflective layer, and various drawbacks of laser beam irradiation fibers caused by the reflective layer are eliminated.

On the other hand, in order to make the reflective surface at the end of the output side of the fiber wire a total reflection surface, the closed end of the transparent cylinder fitted to the tip of the fiber wire is almost closed so as to form an air layer adjacent to the reflective surface. Since it has a hemispherical shape, it is difficult to break, and there is no risk of damaging the inner wall of the hollow organ.

In the above embodiment, the material of the transparent cylinder can be selected from plastic, glass, ceramic, etc. as long as it satisfies the required optical properties such as transmittance and refractive index. The suitability for use can be improved by using a material that is difficult to clean, a material with excellent heat resistance, or by applying a coating thereof on the outer peripheral surface.

〔Effect of the invention〕

The laser beam side-emitting fiber of the present invention can introduce the laser beam endoscopically into the living body's luminal organs and irradiate the lesioned area from the front. Burning of the laser beam emitting end of cotton (
This has the remarkable effect that there is no risk of damage to the tip or tip, or even damage to the hollow organs.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of a laser beam side-emitting fiber according to the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1. 11-Fiber wire, 12-.-Primary coating layer, 13-Protective jacket tube, 14-Slanted surface, 15-Transparent cylinder, 17-Air layer, 19-Reinforcement tube, 20-
spout, 21-void;

Claims (2)

[Claims] (1) A laser beam transmitted through a fiber wire consisting of a core and a cladding having different refractive indexes is reflected and bent by approximately 90 degrees to emit the laser beam laterally in the length direction of the fiber wire. In the fiber for laser beam side emission, an inclined surface of about 45 degrees with respect to the center line of the fiber wire is formed at the tip of the fiber wire, and one end is closed at the end of the fiber wire including this inclined surface. 1. A fiber for side emission of a laser beam, characterized in that a transparent cylindrical body is fitted to provide an air layer adjacent to an inclined surface, thereby making the inclined surface a total reflection surface. (2) The transparent cylindrical body is provided with an air injection port that communicates with a gap formed by the fiber wire and a flexible tube body sheathed thereon. The laser beam side emission fiber according to item 1.