JP3446272B2 - Endoscope with measurement function - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for observing an affected area of a living body, adjusting laser output, and performing spectrum analysis diagnosis,
The present invention relates to an endoscope with a measuring function, which has a function of measuring a distance to an observation section and a size of the observation section.

[0002]

2. Description of the Related Art In observing an affected area of a living body using an endoscope, adjusting laser output, and performing spectrum analysis diagnosis, it is possible to measure the distance from the distal end of the endoscope insertion portion to the observation portion and the size of the observation portion. This is important and is conventionally performed by the following method. What can be marked on the scale or actual size from the endoscope insertion part is inserted under endoscopic observation through the forceps hole of the endoscope,
This measures the distance. While observing the observation part, the endoscope is moved, the affected part is aligned with two scales, and the distance is calculated from the positional relationship of the combined endoscope insertion parts (for example, Japanese Patent Laid-Open No. 1-250225). One laser beam is radiated from the endoscope insertion portion to the affected area in parallel with the long axis direction of the endoscope insertion portion to measure the distance (for example, JP-A-63-68127).

[0003]

However, the above-mentioned conventional endoscope has the following problems. The operation of the endoscope according to the above method is complicated. In the endoscope according to the above method, the size of the device becomes large and the operation is complicated. The resolution of distance and position is low in the endoscope according to the method (in other words, the accuracy cannot be increased).

Therefore, an object of the present invention is to provide an endoscope with a measuring function which can improve the distance from the tip of the endoscope insertion portion to the observation portion and the resolution of the position of the observation portion. .

[0005]

[Means for Solving the Problems ]
Therefore , the endoscope with a measuring function of the present invention includes an illumination light output unit that outputs illumination light that spreads in a fan shape from the tip of the endoscope insertion portion,
In an endoscope with a measuring function, comprising a plurality of measuring light output means for outputting a beam of measuring light from the tip of the endoscope insertion portion, and an imaging means for imaging the illumination range of the illumination light output means, The plurality of measurement light output means are arranged so that the measurement light is oblique with respect to the irradiation direction of the illumination light, and the angle of the irradiation direction is such that the spot of the measurement light is within the photographing range of the illumination light. Measuring light refraction means to attach,
From said captured image photographing means, along with identifying the measurement spot each and individually detected, and <br/> calculating means for calculating a three-dimensional position information from the reference point of the surveying constant light spots each, the Of the calculation result obtained by the calculation means
It also has a control means for performing display control on the display means .

Further, in the endoscope with a measuring function of the present invention, the plurality of measuring light output means emits emitted light of different wavelengths for identifying the respective measuring light spots, and the shape of each measuring light spot. And a means for changing the color of the measurement light spot in the optical path.

[0007]

[0008]

[0009]

[0010]

According to the present invention, the beam-shaped measuring light is oblique to the irradiation direction of the illumination light that spreads in a fan shape, and the irradiation direction is angled so that the spot of the measuring light falls within the photographing range of the illumination light. To do. As a result, the measurement light spot position moves from the upper part to the lower part of the observation screen, and the light receiving area of the photographing means becomes wider than in the case of parallel light. Therefore, since the amount of change in the distance per pixel of the image pickup means is small, the ability to detect changes with the distance from the tip of the endoscope insertion part to the observation part is improved. Further, in the present invention, the measurement light is plural. This makes it possible to easily calculate the distance between two points, the area of the observation section including the two points, or the volume of the observation section including the three points. Furthermore, since a plurality of points are used, it is possible to measure the observation part on a surface, a curved surface, or a slope that is not parallel to the endoscope imaging screen.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Example 1. 1 is a block diagram showing a configuration of a first embodiment of an endoscope with a measuring function of the present invention. In this figure, 1
Is a measuring light generator, which generates the measuring light L ₁ focused into a beam. Reference numeral 2 is a measurement light control unit for controlling the measurement light generation unit 1, 3 is a measurement light guide for guiding the measurement light L ₁ generated by the measurement light generation unit 1 to the endoscope insertion unit 50 (see FIG. 2), and 4 is a measurement light guide. It is a refractor (prism or the like) that irradiates the measurement light L ₁ guided by the light guide 3 from the endoscope insertion section 50 toward the endoscope observation area.

Reference numeral 5 denotes an illuminating light generator, which generates illuminating light L ₂ that spreads in a fan shape. Reference numeral 6 is an illumination light guide that guides the illumination light L ₂ generated by the illumination light generator 5 to the endoscope insertion portion 50 (see FIG. 2). Reference numeral 7 denotes an image pickup device (CCD) 7a, and an image pickup system having a lens 7b arranged in front of the image pickup device 7a (on the observation section 51 side: see FIG. 2), and 8 denotes a video signal output from the image pickup system 7. Video input section for inputting 9
Is a video processing unit that processes the video information output from the video input unit 8 and generates a video signal for display from the processing result, 10 is a video output unit that outputs the video signal output from the video processing unit 9, 11 Is a display device such as a monitor, and 12 is a printing device such as a printer. Reference numeral 13 is a measurement switch unit including various switches, which is used for inputting various commands.

The video processing unit 9 comprises an image memory 15, a measurement light detection circuit 16, a primary arithmetic circuit 17, a secondary arithmetic circuit 18, and a display control circuit 19. The image memory 15 records the image taken by the image pickup system 7. The measurement light detection circuit 16 detects the measurement light spot L _sp ,
The position (two-dimensional coordinate) of this on the image pickup device 7a (or on the display screen of the display device 11) is calculated. In this case, the measurement light detection circuit 16 uses the measurement light spot L _sp under the illumination light L _2.
Is identified by comparing the brightness of each element in the image. The primary calculation circuit 17 calculates the actual measurement light spot L _sp from the two-dimensional coordinates calculated by the measurement light detection circuit 16.
Position (three-dimensional coordinate) is calculated. Secondary operation circuit 18
Is the distance from the tip of the endoscope insertion section 50 to the observation section 51 based on the three-dimensional coordinates calculated by the primary operation circuit 17, and the calculation of the display magnification of the display screen based on this distance.
And the observation unit 5 on the display screen based on this display magnification.
The size of 1 is calculated. The display control circuit 19 controls the display of the calculation result and the image at the time of measurement.

FIG. 2 is an enlarged view of the endoscope insertion portion 50.
As shown in this figure, the measurement light guide 3 and the illumination light guide 6
And the imaging system 7 are arranged in parallel. The measurement light guide 3 outputs the measurement light L _{1 which} is focused in a beam shape, and the illumination light guide 6 outputs the illumination light L ₂ which spreads in a fan shape. The measuring light L ₁ is emitted by the measuring light guide 3 after being angled by the refractor 4. In this case, the measurement light L ₁ is oblique to the irradiation direction of the illumination light L ₂ that spreads in a fan shape,
Moreover, the spot is angled so that it falls within the shooting range of the illumination light. Note that the actual shooting range is the area illuminated by the illumination light.
It is defined as the "shooting range by illumination light".

Here, the distance from the tip (observation window) of the endoscope insertion portion 50 to the measurement light spot L _sp is calculated as follows. As shown in FIG. 2, since the observation area of the image pickup device 7a is fan-shaped, when light is output from the endoscope insertion portion 50, the observation portion 51 extends from the tip of the endoscope insertion portion 50.
The two-dimensional coordinates on the image sensor 7a that receive the measurement light spot L _sp change depending on the distance to. By preparing (storing) a conversion table or a conversion formula relating to the two-dimensional coordinates and the actual position (three-dimensional coordinates) from the endoscope in advance, the actual conversion based on the two-dimensional coordinates of the measurement light spot L _sp . The position of the measurement light spot L _sp (coordinates with the tip of the endoscope insertion portion 50 as a reference) can be calculated.

As shown in FIG. 3, as the distance from the distal end of the endoscope insertion section 50 to the observation section 51 increases, the imaged area A expands (from area A ₁ to area A ₂ ). In addition, the measuring light spot L _sp is measured by the endoscope insertion unit 50 and the observation unit 5.
It moves in the area A as it moves away from 1 (from top to bottom in this figure). Now, as shown in FIG. 4 regarding the observation space of the endoscope having the measurement light irradiation function, the center of the observation window is (0, 0, 0), the center of the observation window is included, and the axis of the observation direction is Z axis (at this time, the Z coordinate indicates a distance), a straight line passing through the center of the observation window and the center of the refractor 4 (longitudinal direction of the observation screen) is the Y axis, and a straight line passing through the center of the observation window and orthogonal to the Y axis ( Three-dimensional coordinates with the X-axis in the horizontal direction of the observation screen) are defined, the position of the refractor 4 is (0, g, 0) on the Y-axis, and the downward irradiation angle of the measurement light in the YZ plane is θ2.

For the sake of clarity, a method of calculating the distance d will be described with reference to the Y-Z plane view (FIG. 5) of FIG. 4 viewed from the X-axis direction. Using the known parameters angle of view θ ₁ , measurement light irradiation angle θ ₂ , distance g from the center of the observation window to the center of the refractor 4, and focal length f of the objective lens,
The radius r of the observation screen at the distance d and the distance p from the uppermost end of the observation screen to the measurement light spot L _sp can be calculated as follows (r ₁ is r at the distance d ₁ and p ₁ is the distance d ₁ P).

R ₁ = (f + d ₁ ) × tan (1/2) θ ₁ p ₁ = r ₁ −g + d ₁ × tan θ ₂

Here, the diameter (2 × r ₁ ) of the observation screen and p ₁
Consider the ratio R (p ₁ / (2 × r ₁ )) to R = p ₁ / (2 × r ₁ ) = (r ₁ −g + d ₁ × tan θ ₂ ) / (2 × r ₁ ) = (1/2) − (g−d ₁ × tan θ ₂ ) / (2 × ( f + d ₁ ) × tan (1/2) θ ₁ )

This R (for example, r ₁ and r ₂ ) changes depending on the distance d (for example, d ₁ and d ₂ ) as can be seen from FIG.
It can be measured on the image sensor 7a. Therefore, R, g,
From θ ₁ , θ ₂ , and f, the distance d (for example, d ₁ and d ₂ ) from the center of the observation window to the plane including the measurement light spot L _sp can be calculated. That is, d = (g × tan θ ₂ − (1-2R) × f × tan (1
/ 2) θ ₁ ) / ((1-2R) × tan (1/2) θ ₁ +
tan θ ₂ ).

Thus, if the plane distance d is determined, the enlargement ratio of the observation screen with respect to the image pickup device 7a is decided. Therefore, when the enlargement ratio is n, the coordinates (x, y) on the image pickup device 7a are determined.
Using, the actual three-dimensional coordinates (X, Y, Z) of the measurement light spot L _sp can be obtained as follows. (X, Y, Z) = (nx, ny, d)

Next, the refractor 4 is attached to the tip of the measurement light guide 3.
The measurement light L ₁ is angled by providing a large amount of change in the measurement light spot position (two-dimensional coordinate) on the image sensor 7a depending on the distance from the tip of the endoscope insertion portion 50 to the observation portion 51. This is because That is, when the measurement light L ₁ is collimated as shown in FIG. 6, the measurement light spot position of the image pickup element 7a is changed as the distance from the tip of the endoscope insertion portion 50 to the observation portion 51 increases. Although it moves from the upper part to the central part, the light receiving area of the image pickup device 7a is narrow, which is less than half that of the image pickup device 7a.

On the other hand, as shown in FIG. 7, as the distance from the tip of the endoscope insertion section 50 to the observation section 51 is increased, the measurement light spot position extends from the upper part to the lower part of the image pickup device 7a. It moves and its light-receiving area becomes wider than in the case of parallel light. As a result, the amount of change in the distance per pixel of the image pickup device 7a becomes small, so that the accuracy / resolution of position measurement becomes high. For this reason, the measurement light L ₁ is angled.

The measurement light generating section 1 and the measurement light guide 3 constitute the measurement light output means 100, and the illumination light generation section 5 and the illumination light guide 6 constitute the illumination light output means 110. The refractor 4 corresponds to the measuring light refracting means, and the photographing system 7 corresponds to the photographing means. Further, the video processing section 9 corresponds to a calculation means and a control means. The display device 11 and the printing device 12 correspond to display means. In addition, the measurement switch unit 13
Corresponds to the plane shape designating means or the three-dimensional shape designating means.

Description of Operation In such a configuration, the operator inserts the endoscope into the body, and while observing the affected part, brings the tip of the endoscope insertion part 50 to the vicinity of the target affected part, and the measurement light spot L _The endoscope insertion part 50 is moved so that _sp overlaps with the point to be measured. Then, when the measurement light spot L _sp reaches the measurement point, the measurement switch unit 13 is operated. As a result, the measurement light detection circuit 16 calculates the two-dimensional coordinates. Then, the three-dimensional coordinates of the measurement light spot L _sp are calculated by the primary calculation circuit 17 based on the calculated two-dimensional coordinates.

When the three-dimensional coordinates of the measurement light spot L _sp are calculated, the distance from the tip of the endoscope insertion portion 50 to the surface including the measurement light spot L _sp is calculated by the secondary operation circuit 18 based on this value. Then, the display magnification of the observation screen is calculated based on this distance. Further, the size of the observation unit 51 on the screen is calculated based on the calculated display magnification.
Then, the calculated values (two-dimensional coordinates, three-dimensional coordinates, distance, display magnification, size of the observation unit) are displayed on the display device 11.
And is printed by the printing device 12. In this case, the measurement switch unit 11 and the printing of the observation screen are linked, the image at the time when the measurement switch unit 11 is operated is recorded, and the measurement result is displayed and printed in the memory image in a superimposed manner. Done.

Example 2. In Embodiment 1, various kinds of information by one of the measurement light L ₁ was to obtain a (2-dimensional coordinates, three-dimensional coordinates, the distance, the size of the display magnification and the observation unit), this second embodiment the measurement light L The number of ₁ is increased to obtain more advanced information. For example, FIGS.
As shown in FIG. 6, in the endoscope that irradiates the two measurement lights L _1a and L _1b from the tip of the endoscope insertion portion 50, the two measurement light spots L _spa and L _spb are endoscopic so as to overlap with the point to be measured. Move the mirror and set the two measurement light spots L _spa and L _spb to 3
The distance between these two points can be calculated by calculating the dimensional coordinates.

At this time, if the measuring light spots L _spa and L _spb are positioned at both ends of the observation section 51, the diameter of the observation section 51 can be calculated from the distance between the two points. Further, assuming that the shape of the observation unit 51 is circular,
If the distance between the two points is designated as the diameter of the observation part 51, the area of the observation part 51 can be roughly estimated. It should be noted that there is no problem in measuring this distance even if the observation section 51 is oblique as shown in FIG.

Further, the volume can be roughly estimated by developing the idea of area calculation. As shown in FIGS. 11 and 12, in the endoscope that emits the three measurement lights L _1a , L _1b , and L _1c , the three measurement light spots L _spa , L _spb , and L _spc are located on the observation unit 51. The endoscope is moved as described above, and the respective three-dimensional coordinates are calculated. Next, assuming, for example, a lens-like shape, which portion of the shape has the measurement light spot L
By instructing whether _spa , L _spb , and L _spc are located, the volume of the shape including three points can be roughly estimated. Regarding this area and volume estimation, various areas and volumes can be estimated by registering the calculation method related to the shape from the assumed shape and coordinates in advance in the calculation circuit. , But not limited to the lens shape. It should be noted that the operation switch section 13 may be provided with a shape setting means for setting an assumed shape.

By the way, in the case of using a plurality of measurement light L _1, it is necessary to perform these identification, for example, or Chigae the wavelengths of the measurement light L ₁ respectively, each measurement light L ₁ of the endoscope front end portion 50 The color of the measurement light spot may be changed by using a filter having a different color for the light irradiation hole, or by changing the shape or arrangement of the measurement light L ₁ irradiation holes.

In the above embodiment, as shown in FIG. 13, a refractor 4 using a prism for angling the measurement light L _1.
However, as shown in FIG. 14, a reflector 21 such as a mirror is provided in the endoscope insertion portion 50, and the measurement light L ₁ is passed through from the inside to the outside of the endoscope. Reflector (measurement light refracting means) 21
You may try to hit it. All of the present invention can be applied to a side endoscope. In addition, the refractor 4 and the reflector 21
May not be provided inside the endoscope insertion portion 50, but may be attached so as to project from the endoscope insertion portion 50.

In the above embodiment, the measurement light spot L _sp under the illumination light L ₂ is identified by comparing the brightness of each element in one image. You may make it identify by a difference. Further, the measurement light L ₁ is emitted intermittently, and the difference between the image when the measurement light L ₁ of the same element is emitted and the image where the measurement light L ₁ is not emitted is subtracted (subtraction). Light spot L _sp
May be detected. That is, there is no difference in the illumination light L ₂ that is continuously irradiated, but there is a difference in the measurement light spot L _sp , so that the measurement light spot L _sp can be easily detected. Further, instead of automatically identifying the measurement light L ₁ , the operator may identify / specify the measurement light spot L _sp on the display screen while looking at the display screen.

Further, in the above embodiment, various calculation results for the observation section 51 are shown by numerical values, but the ruler 23 may be displayed on the screen as shown in FIG. 15 based on the calculation results. By allowing the ruler 23 to be moved to an arbitrary place and rotated at an arbitrary angle, the measurement of the object on the screen becomes simple.

Further, in the above embodiment, the measurement light L ₁ is always emitted, but the measurement light L _{1 is} emitted only when necessary.
May be irradiated. By doing this,
It is possible to prevent the image from becoming difficult to see due to the illumination light L _2, and it is possible to shorten the operating time of the measurement light illumination light source.

Further, in the above embodiment, the actual position, the distance from the distal end of the endoscope insertion portion 50 to the measurement spot L _sp of the measurement light spot L _sp, the actual distance between the two measurement spots, observation The measurement error may be calculated when calculating the actual size of the part 51 and the actual volume of the observation part 51. Further, the calculated measurement error may be displayed. Further, in the above-described embodiment, it may be possible to provide a function of adjusting the angle of the measurement light L ₁ , the adjustment adjustment of the illumination light L ₂ and the measurement light L ₁ , and the adjustment adjustment of each measurement light L ₁ . Moreover, it is considered that the development of endoscopes from now on will be centered on stereoscopic endoscopes having a plurality of optical systems, but of course,
It is obvious that the present invention can be applied to this type of endoscope.

[0036]

According to the present invention, the beam-shaped measurement light is irradiated in a direction oblique to the irradiation direction of the illumination light that spreads in a fan shape, and the spot of the measurement light is irradiated within the photographing range of the illumination light. Since the directions are angled, it is possible to improve the ability to detect changes with the distance from the distal end of the endoscope insertion section to the observation section, and the distance from the distal end of the endoscope insertion section to the observation section and The resolution of the position of the observation part is improved. Further, according to the present invention, since the measurement light is plural,
The distance between two points, the area of the observation part including two points, or the volume of the observation part including three points can be easily calculated. Furthermore, by using a plurality of points, it is possible to measure the observation portion on a surface, a curved surface, or a slope that is not parallel to the endoscope imaging screen.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of an endoscope with a measuring function according to the present invention.

FIG. 2 is a diagram showing an insertion portion of the endoscope with a measuring function of the embodiment.

FIG. 3 is a diagram for explaining a measurement principle of the endoscope with a measurement function of the same embodiment.

FIG. 4 is a view for explaining the measurement principle of the endoscope with a measuring function of the same embodiment.

FIG. 5 is a diagram for explaining a measurement principle of the endoscope with a measuring function of the same embodiment.

FIG. 6 is a diagram for explaining the features of the endoscope with a measuring function of the same embodiment.

FIG. 7 is a diagram for explaining the features of the endoscope with a measuring function of the same example.

FIG. 8 is a diagram showing an insertion portion of a second embodiment of the endoscope with a measuring function according to the present invention.

FIG. 9 is a diagram showing a display screen of the endoscope with a measuring function of the embodiment.

FIG. 10 is a view showing an insertion portion of the endoscope with a measuring function of the same example.

FIG. 11 is a view showing an insertion portion of an application example of the endoscope with a measuring function of the same embodiment.

FIG. 12 is a diagram for explaining shape designation in the endoscope with a measurement function of the same application example.

FIG. 13 is a first embodiment of an endoscope with a measuring function according to the present invention.
9A and 9B are views showing a part of the endoscope insertion portion of the second embodiment.

FIG. 14 is a first embodiment of an endoscope with a measuring function according to the present invention.
9A and 9B are diagrams showing another example of a part of the endoscope insertion portion of the second embodiment.

FIG. 15 is a first embodiment of an endoscope with a measuring function according to the present invention.
9A and 9B are diagrams illustrating another example of distance display according to the second embodiment.

[Explanation of symbols]

4 Refractor (measurement light refraction means) 7 Imaging system (imaging means) 9 Image processing section (calculation means, control means) 11 Display device (display means) 12 Printing device (display means) 13 Measurement switch section (planar shape designating means) , Three-dimensional shape designating means) 21 reflector (measuring light refracting means) 50 endoscope insertion portion 100 measuring light output means 110 illumination light outputting means

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Claims (2)

(57) [Claims] 1. An illumination light output unit that outputs illumination light that spreads in a fan shape from the tip of the endoscope insertion unit, and a plurality of measurement light output units that outputs beam-shaped measurement light from the tip of the endoscope insertion unit. When, in the measurement function endoscope having an imaging means for imaging the illumination range of the illumination light output means, said plurality of measuring light output means, either the measuring light with respect to the irradiation direction of the illumination light The measuring light refracting means for angling the irradiation direction so that the spot of the measuring light is in the photographing range of the illumination light in an oblique direction, and the measuring light spot is obtained from the image captured by the photographing means. Each is individually detected and identified, and the calculation means for calculating the three-dimensional position information from the reference point of each of the measurement light spots and the display means for displaying the calculation result obtained by the calculation means are paired.
Control means for performing display control for
An endoscope with a measuring function. 2. The internal view with a measuring function according to claim 1, wherein the plurality of measuring light output means have any one of the following 1, 2 and 3 for identifying each measuring light spot. mirror. 1. 1. Means for emitting emitted light of different wavelengths 2. A means for making each measuring light spot shape different. Means for changing the color of the measuring light spot in the optical path