JPS61231428A - Apparatus for monitoring state of optical fiber - Google Patents

Abstract

PURPOSE:To make it possible to always certainly monitor the state of an optical fiber, by detecting the tension of a thermoplastic wire provided along an optical fiber. CONSTITUTION:The title apparatus is equipped with a holding member 20 for holding the emitting side of the thermoplastic wire 21 provided along an optical fiber 14 and fixing one end thereof and a tension detector 23 present in the insident side of the optical fiber 14 and mounting the other end of the thermoplastic wire 21 in a hanging state and detecting the tension of said wire 21. When damage was generated in the optical fiber 14 by any cause and said optical fiber 14 was fused, the thermoplastic wire 21 is instantaneously heated to temp. equal to or more than thermoplastic temp. by laser beam from the fused part of the thermoplastic wire 21 through a metal tube 19 and fused. By this phenomenon, the balance between the repulsive force of a spring 25 and the tension of the thermoplastic wire 21 is lost and a tube holder 22 is slid to an A-direction and the resistance value of a slide volume 26 changes and, by detecting this change, the fusion of the optical fiber can be detected.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is used in a laser processing device that guides a laser beam through an optical fiber to a processed part or a diseased part, and performs welding, cutting, incision of the diseased part, evaporation, etc. This invention relates to an optical fiber condition monitoring device.

BACKGROUND OF THE INVENTION Laser processing apparatuses or laser scalpels using YAG laser light or Co2 laser light include a mirror joint type and an optical fiber type, which are currently being put into practical use, as light guide paths. The mirror joint method has problems with operability in processing or surgery, and cannot be applied to endoscopes, so it is desired to put optical fiber into practical use as a light guide path. C○2
For laser light, KR8-5, a mixed crystal of cream iodide and thallium bromide, is listed.

KH2-s has the disadvantage that it will break if bent beyond a certain curvature, so it must be used with caution by limiting the curvature.

If the fiber breaks or partially melts due to heat concentration despite the curvature limit, there is a risk that the high-power laser beam will penetrate the external wave and irradiate the patient or operator. there is a possibility.

In addition, the vapor generated when KH2-5 melts may have some effect on the human body, so it is important to prevent the fiber damage mentioned above and constantly monitor the deterioration state of the optical fiber. It was absolutely necessary to do so.

However, although various monitoring methods have been tried in the past, they have various drawbacks and none are perfect.

For example, see the 4th catalog Japanese Patent Application Publication No. 58-103623)
As shown in FIG.
There is a means for monitoring the state of the optical fiber by detecting the light received by the photodetector 6.

Problems to be Solved by the Invention However, since a photodetector is provided on the output side, the configuration on the output side becomes complicated, and cannot be adapted to handpieces that are becoming smaller in size in recent years.

In addition, since there is a photodetector on the output side that becomes part of the electrical circuit, sufficient attention must be paid to insulation and grounding in the design of the non-end beads to prevent leakage current from flowing to the surface of the human body. I had to.

Means for Solving the Problems The technical means of the present invention for solving the above problems is to monitor the condition of the optical fiber by detecting the tension of the thermoplastic wire along the optical fiber at the entrance.

For production The effect of this technical means is as follows.

That is, by detecting the tension of the optical fiber on the input side, the configuration on the output side can be simplified. Still on the exit side,
Since it does not use any electrical circuits, there is no need to take special precautions such as insulation or grounding.

Example Embodiments of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a 9 diagram illustrating the configuration of a carbon dioxide laser scalpel device consisting of a laser body e incorporating an optical fiber condition monitoring device according to the present invention and an optical cable 7. As shown in FIG. A carbon dioxide laser beam 9, shown by a broken line, emitted from a carbon dioxide laser oscillation tube 8 is bent by a mirror 1° and condensed by a condenser lens 11.

The focused laser beam passes through a window 13 at the entrance part 12 of the optical cable, and is connected to an optical fiber 14 made of an infrared optical material such as KH2-TS, which transmits the carbon dioxide laser beam.
The light enters from the incident end of. The transmitted laser light is focused by an output-side condensing lens 16 provided in the handpiece section 16 and guided to the affected area 17, where measures such as incision, evaporation, and hemostasis are performed.

Further, the optical fiber 14 is fixed by an optical fiber chuck 18 at the optical fiber entrance part, and is covered with a protective tube 19 made of metal such as stainless steel.
In the handpiece section 16, the optical fiber holding member 2
It is indirectly held and fixed by fixing the metal tube to the o.

Along the outside of the metal tube is a thermoplastic cube 21 made of a thermoplastic material such as polyethylene. The thermoplastic tube is fixed at the handpiece section by an optical fiber holding member 20, and at the optical cable entrance section is fixed at a tube holder 22 which is slidable coaxially with the metal tube. 23 is a tension detector that detects the tension of the thermoplastic tube, and the tube holder 22. Spring retainer 24. Spring 26.
It consists of a slide volume 26. The tube holder is pushed in the direction A by the repulsive force of a spring holder 24 fixed to the non-end piece and a spring 26 fixed to the spring holder.

26 is a slide volume, and a slide volume stand 27 is fixed to the handpiece section, and a slide section 28 is fixed to the tube holder. In addition, the slide volume is detected by the length change caused by the balance difference between the tension of the thermoplastic tube and the repulsive force of the spring.
Convert to resistance value.

Next, the operation will be explained.

When the laser light is transmitted to the optical fiber, when the optical fiber is normal, the temperature of the thermoplastic tube will rise due to the internal absorption and scattering of the optical fiber, but the increased temperature is compared to the thermoplastic temperature of the thermoplastic. The temperature is sufficiently low, on the order of several tens of degrees, that the thermoplastic tube remains unchanged.

However, if the optical fiber is damaged for some reason and the optical fiber is fused, the thermoplastic tube is instantly heated to a temperature higher than the thermoplastic temperature by the laser beam from the fused part passing through the metal tube. , melt. As a result, the balance between the spring repulsive force and the tension of the thermoplastic tube is lost, the tube holder slides in the input direction, and the resistance value of the slide volume changes.

As per the above explanation of the operation, it is possible to detect the melting of the optical fiber by detecting the resistance value of the slide volume.

In the example, a thermoplastic tube was placed along the outer periphery of the coating of the metal tube as a method for wrapping the thermoplastic wire around the optical fiber, but it is also possible to wrap the thermoplastic wire around the optical fiber shown in Fig. 2. It is also possible to monitor the state of the optical fiber by using the method shown in FIG. 3, in which a thermoplastic wire is directly connected to the optical fiber.

Furthermore, it is also possible to monitor the state of the optical fiber by detecting the tension of the optical fiber for guide light used as a light guide path for the guide light essential to the carbon dioxide laser scalpel device.

As described in detail, according to the present invention, the condition of the optical fiber can be constantly and reliably monitored by detecting the tension in the thermoplastic wire along the optical fiber.

Furthermore, by simply fixing one end of the thermoplastic wire to the handpiece, the structure is simple and can be used with various types of handpieces.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a carbon dioxide laser scalpel device incorporating an optical fiber condition monitoring device according to an embodiment of the present invention, and FIGS. 2 and 3 show a thermoplastic wire of the optical fiber condition monitoring device of the present invention. FIG. 4 is a perspective view showing a state along a fiber, and a sectional side view of a conventional optical fiber condition monitoring device. 14... Optical fiber, 20 Old... Holding member,
21...Thermoplastic wire (thermoplastic tube), 23...Tension detector. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (3)

[Claims] (1) An optical fiber that transmits light energy, a thermoplastic wire provided along this optical fiber, and an output side of the optical fiber of this thermoplastic wire is held, and one end of the thermoplastic wire is fixed. An optical fiber condition monitoring device comprising: a holding member; and a tension detector that is located on the input side of the optical fiber, suspends the other end of the thermoplastic wire, and detects the tension of the thermoplastic wire. (2) The optical fiber condition monitoring device according to claim 1, wherein the thermoplastic wire is a thermoplastic thermoplus kick tube. (3) The optical fiber condition monitoring device according to claim 1, wherein the thermoplastic wire is a guide light optical fiber that guides visible light.