JPS614938A - Optical fiber condition monitoring device - 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 Industrial Application The present invention is for processing a laser beam using an optical fiber.

Conventional configurations and their problems Laser processing devices or laser surgery devices that use YAG laser light or Co2t/- laser light have laser beams that use a plurality of reflecting mirrors to guide the laser light to the processing site or surgical site. There is a so-called mirror joint method that guides light beams, and an optical fiber method that is currently being put into practical use. The mirror joint method has problems such as operability during processing or surgery and misalignment of the mirror angle due to vibration, and to solve these drawbacks, it has been desired to put optical fiber into practical use as a waveguide. For Co2 laser light, KR8-5, a mixed crystal of thallium iodide and thallium bromide, is listed. KH2-5d has the disadvantage that it will break if bent beyond a certain curvature, so it must be used carefully by limiting the curvature. If the fiber breaks or melts due to localized heat concentration despite the curvature limitations, there is a risk that the high-power laser beam will penetrate the outer sheath 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 for use.

However, various monitoring methods have been tried in the past, but all of them have had problems. For example, a method has been considered in which a resin tape whose electrical resistance changes depending on the temperature is wrapped around the entire length of the optical fiber and a rapid temperature rise due to melting or breakage is monitored through the resin tape. However, in this case, the resin tape or the like impairs the flexibility, which is a major advantage of optical fibers, and affects the light transmission characteristics of the fiber, thereby adversely affecting the characteristics of the fiber.

Purpose of the Invention The present invention has been made in view of the above-mentioned conventional drawbacks, and utilizes a sealed structure, which is a necessary condition for safely using an optical fiber that transmits optical energy, to ensure that the condition of the optical fiber is maintained. The purpose is to enable monitoring even when light energy is emitted.

Structure of the Invention The present invention provides an optical fiber including an optical fiber for transmitting optical energy, a sealing structure for sealing the entire optical fiber, and a detector provided in the sealing structure for detecting internal pressure. This is a fiber condition monitoring device.

Description of examples An embodiment of the present invention will be described below with reference to the drawings.

The figure is a configuration diagram of a Co2 laser female optical cable in an embodiment of the present invention. The wavy line 01 is a carbon dioxide laser beam, which passes through the window 3 in the connector part 2 and connects to the optical fiber 4 for optical energy transmission. It is incident.

The emitted laser beam 5 is transmitted through the optical fiber and is focused by a lightning lens 7 in the handpiece section 6, and is applied to the affected area 8 for treatment.

The optical fiber consists of a curvature-limited cable 9 and a metal 4-up 1
The curvature-limited cable mechanically protected by 0 is coated with a resin coating 11.

The optical fiber has a window 12, a connector part 2,
The metal tube 1C>, . . . The optical cable is sealed from the outside air by the hand piece 6 and the condenser lens 7 using gaskets 12, 13, 14, and 15.

This sealed structure is necessary when optical fibers are used for optical energy transmission, and especially when used in a clean area such as an operating room like a laser scalpel, etc. This is an absolutely necessary structure to prevent the release of steam when the optical fiber melts. ! In addition, this is an essential structure when optical fibers are used in endoscopes.

We have invented a device that utilizes this sealing/structure to monitor the condition of the fiber.

16 is a diaphragm type pressure detector, which includes a through hole 17 on the side of the sealed structure, a through hole 18 into the outside air, a diaphragm 19 that is displaced due to the difference in internal and external pressure, and two opposing electrodes 20. This pressure detector has a structure in which a connector electrode 21 is drawn out from the electrode.

Next, the operation of the pressure detector will be explained.

When a laser beam is transmitted through an optical fiber, the optical fiber and the sealed structure such as the metal tube are heated due to absorption of laser energy and light scattering, and the temperature of the air inside increases.
Therefore, the internal air expands and the internal pressure increases. Due to this increase in internal pressure, the diaphragm is displaced in accordance with the increase in internal pressure, and the amount of displacement is converted into electrical output as a capacitance change between the opposing electrodes.

When the fiber is normal, the internal pressure is proportional to the laser energy, so real-time laser energy monitoring is possible by measuring the converted electrical output.

However, if some damage occurs to the optical fiber and absorption increases, the temperature of the optical fiber increases, thereby increasing the internal pressure, and an abnormality can be detected by increasing the converted electrical power.

Furthermore, if the optical fiber is completely fused, all of the incident laser energy becomes a heat source that drastically increases the internal pressure, and an abnormality can be detected by the abnormal increase in electrical output.

The internal pressure can also be detected by using a strain gauge piezoelectric element, an optical displacement detector using light, or the like to detect changes in the displacement plate.

Effects of the Invention As explained above, the present invention utilizes a sealed structure necessary for an optical cable using an optical fiber, and constantly monitors the condition of the fiber. No. 1, the deterioration state of the optical fiber can be reliably detected without changing the characteristics of the optical fiber for detection.

[Brief explanation of the drawing]

The figure is a sectional front view of an optical cable including an optical fiber condition monitoring device according to an embodiment of the present invention. 2...Incidence connector part, 3...Window, 4
・ ・Optical fiber, 6...Handpiece part, 7...
...Condensing lens, 1o...Metal tube, 16
...Diaphragm type pressure detector. Name of agent: Patent attorney Toshio Nakao and one other person

Claims (2)

[Claims] (1) An optical fiber condition monitoring device that includes an optical fiber that transmits optical energy, a sealing structure that seals the entire optical fiber, and a detector that detects internal pressure provided in the sealing structure. (2) The optical fiber condition monitoring device according to claim 1, wherein the detector for detecting internal pressure is constituted by a diaphragm.