JPH08201026A - Endoscope with dimension measurement function - Google Patents

Abstract

PURPOSE: To accurately measure the dimension of an observation target and to measure the distance to it with a simple structure by arranging a plurality of optical fibers for guiding spot light around an image guide and utilizing the spot. CONSTITUTION: Four fibers 3 for guiding spot light are arranged at each 90 degrees around an image guide 1 and further a required number of light guides 4 for lighting are arranged and a coating 5 is covered on them. Then, the incident light of the fibers 3 becomes spots with a regular interval on an observation surface, thus forming a scale bar whose interval is known. As a result, by comparing the observation target on an image and the size of the scale bar and performing operation, each kind of dimension can be measured. Also, the actual dimension of the diameter of the observation image is obtained from the diameter of the observation image and the scale bar and the distance to the observation surface can be calculated from the outer diameter and the visual field angle of a known guide 1. Light which can be distinguished from the guides 4 is introduced into the fibers 3 and light which is different from the other fibers is applied to one of the fibers 3 to easily identify the spots and to confirm operation direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope provided with a function for measuring the size of an observation target by incorporating a spot light guiding fiber into an ordinary endoscope.

[0002]

2. Description of the Related Art In recent years, endoscopes have been widely used for medical purposes and various industrial purposes. It is easy to insert an endoscope into a site that was once dissected or disassembled for observation or is unobservable. It is possible to observe. As a matter of course, there is a demand in these industries not only for observing an object but also for finding out the size of the object, that is, the size and depth thereof, and the amount of movement.

In order to give the endoscope the above-mentioned dimension measuring function, it is necessary to add an appropriate sensing element,
As such a sensing element, a mechanical type, an electrical type, a fluid type, and an optical type can be used because of its detection principle. Among them, the optical type using an optical fiber has the advantage that it can be easily reduced in diameter and length, is not affected by noise, and there is no risk of electric shock to the human body, which is of paramount importance in medical applications. Therefore, it is currently positioned as the most preferable sensing element.

The conventional optical sensing element proposed above is as follows: (a) Emitting parallel light from the endoscope tip through two optical fibers to monitor an image, and By moving the emission surface of the optical fiber using an actuator whose movement amount is known with respect to the manipulated variable, the distance between the two emission lights, which can be always known, is scaled and the emitted light is used as an object. A method of measuring the dimensions of various objects on a monitor by irradiating,
(B) The ring beam collimated from the tip of the endoscope is projected as a laser marker on an arbitrary surface of the observed object,
There is a method of comparing and calculating the size of the object on the observed image and the actual size of the marker.

[0005]

However, the above method (a) requires an elaborate actuator that moves the emitting surface of the optical fiber extremely accurately, and the measurement range is such that the optical range at the distal end of the endoscope is the same. There is an inconvenience that the fiber is limited to a movable range and the distance to the observation target cannot be measured. Also, above (b)
The method (1) has a drawback that the optical system for obtaining the collimated ring beam becomes very complicated, and it is extremely difficult to reduce the diameter (1 mm or less) of the endoscope distal end portion.

Therefore, the present invention has an object to provide an endoscope with a dimension measuring function, which is capable of performing accurate dimension measurement of an observation object and distance measurement to the observation object, and which is simple and suitable for reducing the diameter. And

[0007]

An endoscope with a dimension measuring function according to the present invention comprises an image guide and a plurality of spot light guiding fibers which are regularly arranged around at least an end face of the image guide. It is characterized by having.

The above-mentioned image guide is not particularly limited, and a normal one can be used. For example, an image guide made of multiple fibers obtained by converging a plurality of silica glass optical fibers having a support layer and drawing them. Can be used. Also, various ordinary optical fibers can be used as the spot light guiding fiber. The optical fibers are required to be regularly arranged around the end face of the image guide. In this mode, about 2 to 12 optical fibers are arranged at regular intervals around the end face of the image guide. Particularly, the mode in which four optical fibers are arranged at every 90 degrees is particularly preferable in that a grid-like spot can be formed on the observed image and it is advantageous for various dimension measurements.

The spot light guiding fiber is not particularly limited as described above, and various fibers such as a multimode fiber and a single mode fiber can be used. Among them, the single mode fiber is preferable because it has an advantage that the spot can be made small because the core diameter is small.

Normally, it is necessary to equip an endoscope with a light guide for illuminating an observation site. This light guide is constructed by arranging a large number of optical fibers for the light guide around the image guide. It In the present invention, the spot light guiding fiber is mixed in the light guide optical fiber. In this case, therefore, it is necessary to guide the light guide and the spot light guiding fiber to mutually distinguishable lights. is there. Here, the lights that can be distinguished from each other typically mean lights having different wavelengths. For example, white light is guided to a light guide optical fiber and red or blue light is guided to a spot light guiding fiber. It is what makes me.

Further, by injecting light having a color different from that of the other spot light guiding fibers into at least one of the spot light guiding fibers, the relative length of the fiber with respect to the observation object of the distal end surface of the endoscope. This position can be known. Therefore, the operation direction can be confirmed, which is more preferable.

[0012]

The light incident on the spot light guiding fibers arranged regularly according to the above structure becomes spots having regular intervals on the observation surface. Since the distance between the centers of the respective spots is known, it means that the scale bar is substantially formed on the observation target by the irradiation of the spot light.
Since the actual dimensions of the scaler are known, various dimensions of the observation target can be measured by comparing and calculating the sizes of the observation target and the scaler on the observed image.

Further, since the measurement is performed by the comparison calculation with the scaler, the measurement range is not limited as long as it is within the range that can be observed by the endoscope.

Further, by obtaining the actual size of the diameter of the observed image from the diameter of the observed image and the scale bar, the known image guide outer diameter and the distance from the viewing angle to the observation surface can be measured. That is, the diameter of the observed image is Dm, the distance between the centers of adjacent spots in the observed image is Am, and the distance between the centers of adjacent spot light guiding fibers is A,
Further, assuming that the outer diameter d of the image guide and the viewing angle θ are known, the distance L to the observation surface is L = (Dm / Am * A-
d) / 2 tan (θ / 2).

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the endoscope of the present invention. A spot light guiding fiber 3 is provided around the image guide 1 having an objective lens at its tip every 90 degrees. The endoscope with a dimension measuring function is configured by arranging four of them, covering the outer cover 5 thereon, and further arranging the required number of light guides 4 for illumination. In addition,
In this embodiment, the endoscope having only the dimension measurement function is shown, but the function to be added is not particularly limited, and other functions such as a swing function and a working channel may be added.

The coating material used for the outer cover is not particularly limited and may be appropriately selected depending on the intended use. For example, in the case of medical use, polyethylene, polyurethane, polyamide, polyimide, from the viewpoint of biocompatibility, Polytetrafluoroethylene and the like are preferable. Further, the method of fixing the endoscope is not particularly limited, and adhesives such as epoxy resin, polyurethane, polyester, polyamide, etc. may be used, but in the case of medical use, for example, epoxy resin, polyurethane from the viewpoint of biocompatibility and the like. Is preferred.

A specific example of dimension measurement will be shown below. [Specifications of Endoscope] Image guide 1 in the above configuration
As 6000 pixels, outer diameter d350 μm, objective lens 2
With a viewing angle θ of 60 degrees, the spot light guiding fiber 3 has a core diameter of 5 μm and a clad diameter of 60 μm.
m, 4 single mode fibers with a precoat diameter of 100 μm, 50 light guides with an outer diameter of 50 μm, and an outer jacket 5 with an inner diameter of 0.9 mm and an outer diameter of 1.0 m.
Outer diameter 1.0m produced using m polyamide tube
m endoscope was used. The distance A ′ (see FIG. 2) between the centers of the diagonal spot light guiding fibers 3 is 0.7 m.
m. The observation surface 6 was observed using this endoscope.

[Measurement of Dimension of Observation Object] As an example of dimension measurement, it is assumed that an observation image 11 as shown in FIG. 3 is obtained by using the above endoscope. The actual dimension A of the distance Am between the centers of the adjacent spots 13 in the observed image 11 is 0, when the distance A ′ between the centers of the diagonal spot light guiding fibers 3 is 0.
Since it is 7 mm, it is calculated to be about 0.495 mm. In addition, the width W of the observation target 12 in the observation image 11
m and the ratio W of the distance Am between the centers of the adjacent spots 13
The m / Am is 1.76 from the image 11. Therefore, the width W of the observation target 12 is about 0.
It becomes 871 mm. Also, this observation image 11 is transmitted to the communication case.
By importing to a computer via a bull, etc.,
It is also possible to obtain the area, roundness, etc. using image processing software.

[Measurement of Distance to Observation Surface] As for the distance L to the observation surface 6, the diameter Dm of the observation image 11 and the distance Am between the centers of the adjacent spots 13 to the actual observation image 11 are shown in FIGS. Dimension D is D = 0.495 × Dm / A
It is found by m, and Dm / Am is 2.8 from the image 11, so D = 1.386. In addition to this,
Since it is known that the outer diameter of the guide is d = 350 μm and the viewing angle θ is 60 degrees, the distance L = (1.38
6-0.35) / 2 tan (60/2) is calculated, and L =
It is required to be 0.897 mm.

In the endoscope according to the present invention, when a single mode fiber is used as the spot light guiding fiber 3, the core diameter is small and the opening angle is small, so the spot 13 is small and interference with the observation object 12 is small. . Therefore, it is possible to observe the spot 13 without being aware of it during the observation.

If light that can be visually discriminated from the light guide 4 is guided to the spot light guiding fiber 3, the spot 13 on the observed image 11 becomes clear, and the spot 13 becomes clear.
Can be easily identified. Further, in order to make the spot 13 more clear, it is preferable to change the color depending on the background color of the observation target.

At least one of the spots 23 and 24 projected on the observation surface as shown in FIG. 4 is obtained by making light different from that of the other spot light guiding fibers 3 incident on at least one of the spot light guiding fibers 3. One different colored spot 24 is projected onto the viewing surface. The observation target 22 on the distal end surface of the endoscope with reference to the different light spots 24
It is possible to know the relative position with respect to and to confirm the operation direction, which is advantageous in terms of operation particularly when another function is added (for example, a swing mechanism).

[0023]

EFFECT OF THE INVENTION Since the spot light guiding fiber is provided and the spot projected from this is used, the structure is extremely simple, and the processing and assembling techniques also use the conventional technique to measure the size of the observation target. The resulting endoscope can be made. Therefore, it is possible to reduce the diameter of the endoscope with the dimension measuring function and reduce the cost. Further, since the measurement is performed by comparison calculation with the distance between the centers of the spots, various dimension measurements can be performed in a relatively wide range.

Further, the spot can be made clear by guiding the light which can be discriminated from the light guide to the spot light guiding fiber, and at least one of the spot light guiding fibers is connected to another spot light guiding fiber. By guiding the light that can be discriminated, the operation direction can be confirmed with reference to the spot. Therefore, the endoscope can be made more excellent in operability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an endoscope with a dimension measuring function of the present invention.

FIG. 2 is an explanatory diagram showing a usage example of the endoscope with a dimension measuring function of the present invention.

FIG. 3 is a schematic diagram of an observation image in a usage example of the endoscope with a dimension measurement function of the present invention.

FIG. 4 is a schematic diagram of an observation image in another usage example of the endoscope with a dimension measuring function of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Image guide 2 Objective lens 3 Fiber for spot light guiding 4 Light guide 5 Outer cover 6 Observation surface 11, 21 Observation image 12, 22 Observation target 13, 23 Spot light projected on observation surface 24 Projection on observation surface Spot light whose color is different from that of other spot lights θ Viewing angle A ′ Distance between centers of diagonal spot light guiding fibers D D Actual size of viewing range (observation image diameter) on the viewing plane Am Observation Distance between centers of adjacent spot light guiding fibers in the image Dm Observation image screen diameter Wm Observation object lateral width in the observation image

Claims (4)

[Claims] 1. An endoscope with a dimension measuring function, comprising: an image guide; and a plurality of spot light guiding fibers regularly arranged around at least an end face of the image guide. 2. The endoscope with a dimension measuring function according to claim 1, wherein the spot light guiding fiber is a single mode fiber. 3. A plurality of illumination light guides are provided around the image guide, and the light guide and the spot light guiding fiber are configured to guide mutually discriminable lights. An endoscope with a dimension measuring function according to claim 1. 4. The spot light guiding fiber is configured so that light having a different color from other spot light guiding fibers is incident on at least one of the spot light guiding fibers.
An endoscope with the described dimension measurement function.