JPH0326964B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to the distal end of an endoscope that is inserted into a living body cavity and used to observe a diseased area, etc. This relates to the distal end of the endoscope.

[Prior Art] The distal end of an endoscope must be made as thin and small as possible in consideration of ease of insertion, but in general, a node ring in a curved section is connected to the main body of the distal end with a screw. Ru. Due to the requirement for strength in screwing the joint ring into such a limited space and protection against X-ray radiation, the tip body must be made of metal, and is generally made of stainless steel. is used.

On the other hand, when inserting a high-frequency treatment instrument into the forceps channel of an endoscope to perform resection or other treatment of the affected area, leakage of high-frequency current to the metal parts that make up the endoscope is unavoidable. The metal part of the endoscope is electrically connected to the negative side of the high-frequency generator to feed back leakage current.

Therefore, if a metal part is exposed at the tip of the endoscope, when a high-frequency current is passed through the affected area with a treatment instrument, the high-frequency current will enter the feedback circuit via the metal part that is in contact with the inner wall of the body cavity. There is a risk of burns to the inner wall of the body cavity at the point of contact. Therefore, in the past, the periphery of the metal tip body was covered with an electrically insulating cover.

[Problems to be Solved by the Invention] In the distal end of the conventional endoscope described above, the periphery of the distal end main body is covered with an insulating cover, but the conduit such as the forceps channel or water channel is made of metal. They were connected to the tip body, and the tip body was exposed on the inner surface of these conduits. Therefore, the inner wall of the body cavity becomes electrically conductive with the tip body through the water or mucus, etc. in these pipes, and the inner wall of the body cavity that is in contact with water, etc., suffers burns from the high-frequency current, which is a serious drawback. It was hot.

In addition, in the case of so-called electronic endoscopes that use solid-state imaging devices such as CCDs (charge-coupled devices), if current from the device drive system leaks into the tip body due to some kind of failure, the conduit There was a risk of electric shock caused by the water inside.

This invention eliminates such conventional drawbacks and
The purpose of the present invention is to provide a highly safe endoscope tip that does not cause any risk of burns or electric shock.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the distal end portion of the endoscope according to the present invention has the following features: The periphery of the distal end body made of metal is covered with an electrically insulating cover. In the distal end of the endoscope, the distal end of the endoscope is provided with a through hole that penetrates the distal end main body and the insulating cover and opens on the surface of the insulating cover, and the distal end of an electrically insulating tube for passing fluid. , the distal end portion is inserted into the through hole from the rear of the tip main body and joined to the insulating cover.

[Function] The tip of the electrically insulating tube for passing fluid is inserted into the through hole from the rear of the tip body and joined to the insulating cover, so water, mucus, etc. inside the tube will not flow inside the tip body. Completely insulated from the metal parts that make up the endoscope.

[Example] An example of the present invention will be described based on FIGS. 1 and 2.

FIG. 2 is a sectional view of the distal end 1 of the endoscope according to the present embodiment in a plane including the objective optical system. An insulating cover 3 made of synthetic resin having electrical insulation properties is covered and fixed with adhesive. Reference numeral 4 denotes a curved portion that is provided continuously behind the tip portion 1 and bent by remote control, and the most advanced node ring 5 is fitted onto the outer periphery of the rear end portion of the tip portion main body 2. , are connected and fixed by screws 6. The outer surface of the curved portion 4 is covered with an insulating cover 7 made of rubber that is flexible and has electrical insulation properties, and the insulating cover 7 is fixed to the outer periphery of the rear half of the tip body 2 by adhesive. There is. 8 is a node ring, and 9 is a connecting shaft that rotatably connects the node rings.

10 is a solid-state image sensor made of, for example, a CCD, 10a is a light receiving part, and 10b is a solid state image sensor formed on the surface thereof to prevent dust from adhering to the light receiving part.
For example, it is a transparent layer made of transparent epoxy resin. The output signal from the solid-state image sensor 10 is amplified by an amplifier circuit formed on the substrate 11, and is sent to a monitor device via a rear signal processing circuit via a cord 13 passing through the shielded cable 12. connected (not shown). An electrically insulating tape 14 made of, for example, synthetic resin is wrapped around the outer periphery of the solid-state image sensor 10 and the substrate 11 and is adhesively fixed within a metal frame 15. An electrically insulating tape 16 made of, for example, synthetic resin is wound. and frame 1
5 is fitted into a through hole 17 formed in the tip body 2, and is pressed and fixed within the tip body 2 by a screw 18.

In this way, the insulating tapes 14 and 16 ensure insulation so that no electrical continuity or leakage occurs between the solid-state imaging device 10, the frame 15, and the tip body 2. Further, the frame 15 penetrates through the through hole 17 and protrudes forward thereof, and the tip portion 15a of the frame 15 reaches into the hole 3a formed on the back surface of the insulating cover 3, and the insulating tape 16 on the outer periphery is in contact with the insulating cover 3, so that the frame 15 and the tip body 2 are not electrically connected.

Further, the vicinity of the end of the shielded cable 12 is filled with a filler 19 such as epoxy resin or silicone resin to completely secure and insulate each member in the vicinity.

The frame 15 is grounded via the ground wire 20 of the shielded cable 12 to prevent noise from entering the solid-state image sensor 10. On the other hand, the tip main body 2 is not grounded and can be electrically connected to the negative side of the high frequency generator when using the high frequency treatment tool.

21 is the light receiving section 10a of the solid-state image sensor 10;
These objective lens groups 21 are adhesively fixed within a metal lens frame 22, and the rear end 22a of the lens frame 22 is an objective lens group that forms an observation image.
is electrically connected and fitted and fixed to the frame 15. Further, reference numeral 31 denotes an aperture of the objective lens group, and this aperture 31 is made of metal and is electrically connected and fixed to the lens frame 22.
is electrically grounded via. Therefore, the aperture 31 and lens frame 22 are the solid-state image sensor 10.
It plays a role in preventing noise from entering from the front.

Further, the front end portion 22b of the lens frame 22 is fitted into a hole formed in the insulating cover 3, so that the most advanced objective lens 21a is exposed on the surface of the insulating cover 3. The front end surface of the lens frame 22 is arranged at a position recessed a little (for example, 1 mm) from the surface of the insulating cover 3, and the recess is filled with, for example, an epoxy resin adhesive 23 to provide insulation between the lens frame 22 and the outside. is ensured.

FIG. 1 is a cross-sectional view of the distal end portion 1 of the endoscope according to the present embodiment in a plane including the forceps channel 24 and the air/water supply channel 25. As shown in FIG.

A forceps port 26 for protruding a biopsy forceps or a high-frequency treatment instrument, and an air/water supply port 27 for blowing out air and water are formed on the surface of the insulating cover 3. The passages (holes) 28 and 29 in the insulating cover 3 that communicate with the forceps port 26 and the air and water supply port 27 communicate with holes 38 and 39 that penetrate the tip body 2 in the front and back. (holes) 28, 29 and holes 38, 39, a through hole 4 that penetrates the tip body 2 and the insulating cover 3
8,49 are formed. A forceps channel 24 and an air/water supply channel 25 are inserted into these through holes 48 and 49 from the rear side of the tip body 2, respectively.
The tip of the insulating cover 3 is inserted through the insulating cover 3 so that there is no step, and is adhesively fixed to the passages 28 and 29 of the insulating cover 3. Both channels 24 and 25 pass through the tip body 2, pass through the curved portion 4, and reach a rear operating section (not shown).

The forceps channel 24 is an electrically insulating tube made of, for example, tetrafluoroethylene resin, and together with the passage 28, forms a conduit through which a biopsy forceps or the like is inserted. In addition, the air and water supply channel 25
is an electrically insulating tube made of polyethylene resin, for example, and together with the passage 29 forms a conduit through which air or water passes.

Reference numeral 30 denotes a nozzle that is installed in the air and water supply port 27 and directs the jetting direction of air and water toward the surface of the objective lens 21a at the tip.This nozzle 30 is made of metal for strength reasons. , as shown in FIG. 1, is adhesively fixed near the surface of the insulating cover 3 so as not to come into contact with the tip body 2 or other metal parts.

As described above, in the distal end of the endoscope of this embodiment, a conduit through which the biopsy forceps or air or water passes is formed by the electrically insulating cover 3 and the tubes 24 and 25. , the metal constituting the tip end body 2nd class endoscope is not exposed in the conduit. Therefore, water, mucus, etc. in the conduit do not come into contact with the metal parts of the endoscope, and when using a high-frequency treatment instrument, the high-frequency current used to remove the affected area passes through the water, mucus, etc. There is no flow to metal parts.

In the above embodiment, a solid-state image sensor is used in the observation optical system, but an optical image guide fiber or the like may be used instead. , a strabismus type or a visual field conversion type.

[Effects of the Invention] According to the tip of the endoscope of the present invention, water, mucus, etc. in the conduit are completely insulated from the metal parts of the endoscope such as the tip body, so it is easy to use when using a high-frequency treatment instrument. High safety is ensured, with no risk of burn accidents.

In addition, since there are no exposed metal parts in the conduit, electricity can be safely applied even if the conductive wire of the high-frequency treatment device is located in the conduit (forceps channel), resulting in highly safe operation. You can have the freedom of

Furthermore, even if dangerous current leaks into the metal parts that make up the endoscope due to some kind of malfunction, there is no risk of electric shock through water in the pipes, etc., making it extremely safe. effective.

Moreover, in the present invention, since the tip of the tube is simply joined to the insulating cover for electrical insulation, it is easy to manufacture and has excellent durability, ensuring electrical safety for a long period of time. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the distal end of an endoscope according to an embodiment of the present invention in a plane including a forceps channel and an air/water supply channel, and FIG.
FIG. 3 is a cross-sectional view on a plane including the objective optical system. 1... Tip portion, 2... Tip body, 3... Insulating cover, 7... Insulating cover, 24... Forceps channel, 25... Air and water supply channel, 26... Forceps port, 27... Air supply Water supply port, 28...Aisle, 29
……aisle.

Claims (1)

[Scope of Claims] 1. The periphery of the metal tip body is covered with an electrically insulating cover, and the tip body and the insulating cover are penetrated to open on the surface of the insulating cover. In the distal end of the endoscope in which the through hole is formed, the distal end of an electrically insulating tube for passing fluid is inserted into the through hole from the rear of the distal end body and joined to the insulating cover. A distal end portion of an endoscope characterized by: