JP6005488B2 - Ophthalmic observation system - Google Patents

Description

  The present invention relates to an ophthalmic observation system.

  Glaucoma is one of the diseases of the eye, and is a disease in which the optic nerve is damaged, resulting in visual field defects and visual field narrowing. If this condition worsens, there is a risk of blindness. As a cause of glaucoma, it is considered that aqueous humor circulating from the posterior chamber to the anterior chamber in the eyeball becomes difficult to be discharged out of the eyeball, the intraocular pressure increases, and the optic nerve is compressed.

  As shown in FIG. 1, the aqueous humor is discharged through the trabecular meshwork present in the anterior chamber corner 104 between the root of the iris 103 and the root of the cornea 102. Possible causes of the difficulty in draining aqueous humor include a case where the trabecular meshwork is clogged or a case where the anterior chamber corner 104 is narrowed or occluded. Therefore, in order to treat and prevent glaucoma, it is important to observe the anterior chamber angle 104 and find an abnormal site.

  However, as shown in FIG. 1, the anterior chamber corner 104 is blocked by the cornea 102 and cannot be directly observed from the front of the eyeball 101. Therefore, usually, when observing the anterior chamber corner 104, a special contact lens called a corner mirror is brought into contact with the eyeball 101 of the subject, and an observer (doctor or the like) is used using a slit lamp microscope. Observe visually.

  However, since the range that can be observed with the angle mirror is narrow, in order to observe the anterior chamber corner 104 over the entire circumference, it is necessary to change the direction of the lens, which is a burden on both the observer and the subject. It was. In order to cope with such a problem, as described in Patent Documents 1 and 2, a corner mirror that can observe the entire circumference or a wide range of the anterior chamber corner angle 104 has been proposed.

Japanese Patent No. 3346775 Specification Japanese Patent Laid-Open No. 5-15493

  By using the angle mirror described in Patent Documents 1 and 2, the anterior chamber angle can be observed over the entire circumference (annular) or over a wide range. However, an abnormal part was found in the anterior chamber corner angle during observation, and even if an attempt was made to enlarge that portion, this observation image lacks azimuth information, so that portion corresponds to any location in the anterior chamber angle. There was a problem of not knowing what to do. Further, even when a normal angle mirror is used, there is a problem that it is not possible to know where the anterior chamber corner is observed if the observer is not careful.

  In particular, when observing with a video camera attached to a corner mirror, the orientation of the image displayed on the screen does not correspond to the orientation of the part being observed, so the above problem is likely to be significant. It is done.

  The present invention has been made in view of the above problems, and provides an ophthalmic observation system capable of associating azimuth information that can be easily recognized by an observer with an observation image at an anterior chamber corner where azimuth information is missing. The main purpose.

  In order to solve the above problems, the present inventors obtain orientation information that can be easily recognized by an observer from an observation image or a sensor in a region other than the anterior chamber corner angle, and obtain this information in advance. The present inventors have found that the above-mentioned problems can be solved by associating with an observation image at a corner of the chamber, and have completed the present invention.

That is, the aspect of the present invention is
An ophthalmic observation characterized by comprising an associating means for associating azimuth information recognizable by an observer with an image of the anterior chamber angle captured using an imaging unit capable of directly observing the anterior chamber angle inside the eyeball System.

  The associating means preferably uses iris features.

Preferably, first image acquisition means for acquiring at least a first image obtained by imaging the iris;
A second image acquisition means for acquiring a second image obtained by imaging the anterior chamber angle and the iris using an imaging unit capable of directly observing the anterior chamber angle inside the eyeball;
The association means includes first association means and second association means,
The first associating means is means for associating azimuth information recognizable by an observer with the feature of the iris in the first image,
The second association means associates the azimuth information with the anterior chamber angle image by associating the feature of the iris in the first image with the feature of the iris in the second image. It is characterized by being.

Preferably, the first image acquisition unit acquires a first image obtained by imaging the iris and an eye peripheral region having characteristics corresponding to orientation information recognizable by an observer,
The first associating means includes azimuth information acquiring means for acquiring azimuth information recognizable by an observer by associating the feature of the iris with the feature of the eye peripheral region,
The second association unit associates the feature of the iris in the first image having the direction information acquired by the direction information acquisition unit with the feature of the iris in the second image, It is means for associating the azimuth information with the image of the anterior chamber corner.

  Preferably, the second associating means associates the overall feature of the iris in the first image with which the orientation information is associated with the feature of at least a part of the iris in the second image to thereby obtain the orientation information. Is associated with the entire image of the anterior chamber corner.

Preferably, it has display means for displaying an image of the anterior chamber corner,
The display of the image displayed on the display unit is corrected so that the orientation on the image displayed on the display means matches the orientation information associated with the image obtained by the association means.

  Preferably, a function of superimposing and displaying a mark indicating an arbitrary place on the image obtained by the association means is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the ophthalmic observation system which can link | relate the azimuth | direction information which an observer can recognize to the observation image of the anterior chamber corner angle from which azimuth | direction information was missing can be provided.

FIG. 1 is a diagram illustrating a planar cross-sectional structure of an eyeball. FIG. 2 is a schematic configuration diagram of an ophthalmic observation system according to an embodiment of the present invention. FIG. 3 is a view for explaining the first association means in the embodiment of the present invention. FIG. 4 is a diagram for explaining the second association means in the embodiment of the present invention. FIG. 5 is a schematic configuration diagram of an ophthalmic observation system according to a modification of the present invention. FIG. 6 is a diagram for explaining the association means in the modification of the present invention. FIG. 7 is a view for explaining means for associating azimuth information with an anterior chamber corner image using an ophthalmic observation system according to a modification of the present invention.

Hereinafter, the present invention will be described in detail in the following order based on embodiments shown in the drawings.
1. 1. Configuration of an ophthalmic observation system 2. Processing performed in the processing unit Effect of the present embodiment 4. Modifications etc.

(1. Configuration of an ophthalmic observation system)
In this embodiment, an ophthalmic observation system that uses the features of the iris to relate the orientation information recognizable by the observer to the anterior chamber corner image will be described. FIG. 2 is a schematic configuration diagram of the ophthalmic observation system 1 according to the present embodiment. The ophthalmic observation system 1 includes an imaging unit (camera) 10 and a computer unit 20 as shown in FIG. Hereinafter, each component will be described.

  The imaging unit 10 includes a first optical system 11, a second optical system 12, and an imaging element 13. The imaging unit 10 may capture a still image or a moving image.

  The first optical system 11 has an imaging optical system for forming an optical image to be observed on the light receiving surface of the imaging device, and in the present embodiment, the first optical system 11 includes a predetermined number of lenses. The first optical system 11 may further include an illumination optical system such as a filter or a light source that illuminates the observation target, an optical function such as a diaphragm or zoom, a means for suppressing aberration, and the like as necessary. .

  In the present embodiment, the first optical system 11 images the peripheral region of the subject's eye (hereinafter also referred to as the subject eye). Specifically, the first optical system 11 captures an image including an iris and a region around the eye including features corresponding to orientation information that can be recognized by an observer. You may image not only one image but multiple images.

  Similar to the first optical system 11, the second optical system 12 has an imaging optical system for forming an optical image to be observed on the light receiving surface of the imaging element. A corner mirror that can directly observe at least a part of the tuft angle is included. Further, the second optical system 12 may have an illumination optical system or the like as necessary, like the first optical system 11. In the present embodiment, an image of the anterior chamber corner that cannot normally be observed is obtained by bringing the angle mirror into contact with the eye to be examined and refracting light emitted from the anterior chamber corner angle using a prism or the like constituting the angle mirror. Is imaged on the light receiving surface. The angle mirror that can directly observe at least a part of the anterior chamber corner angle is not particularly limited, and for example, the angle mirror disclosed in Patent Documents 1 and 2 described above may be used.

  In the present embodiment, the second optical system 12 captures an image including an anterior chamber corner angle and an iris. You may image not only one image but multiple images.

  The image sensor 13 converts the light reaching the light receiving surface into an electrical signal and sends the electrical signal to the processing unit 21. Although a film may be used instead of the image sensor 13, it is preferable to use the image sensor 13 in consideration of image processing described later.

  In the present embodiment, the first optical system 11 and the second optical system 12 share the image sensor 13. That is, the first optical system 11 and the second optical system 12 can be switched and used according to the type of image to be captured. Instead of switching between the first optical system 11 and the second optical system 12, the second optical system 12 may be attached to the first optical system 11.

  In this embodiment, the computer unit 20 includes a processing unit 21, a display unit 22, a storage unit 23, and an operation unit 24, and is configured with a known computer.

  The processing unit 21 receives an electrical signal of an observation image (first image, second image, etc.) sent from the imaging unit 10 and acquires or processes the observation image. The processing unit 21 has various functions, details of which will be described later.

  The display unit 22 is not particularly limited as long as it has a function of displaying an image captured by the imaging unit 10, an image processed by the processing unit 21, and the like, and a known monitor may be used.

  The storage unit 23 stores a program for executing the function in the processing unit 21, and the program is activated when various functions are executed. Moreover, the acquired image etc. can be stored. Moreover, you may have external storage means, such as a memory card.

  The operation unit 24 has a function of inputting commands to the imaging unit 10, the processing unit 21, and the like from the outside. In addition, the touch panel etc. which the display part 22 and the operation part 24 integrated may be sufficient.

(2. Processing performed in the processing unit)
(First image acquisition unit 41)
When an image is captured using the first optical system 11, the captured image is converted into an electrical signal, sent to the first image acquisition unit 41 of the processing unit 21, and as shown in FIG. And an image (first image 51) including the features corresponding to the orientation information that can be recognized by the observer (in FIG. 3A, the eyelid 105, the eyelash 106, the inner eye angle 107, and the like). The first image 51 can be displayed on the display unit 22 as necessary.

(First association unit 31)
The acquired first image 51 is sent to the feature detection unit 43 of the first association unit 31 to detect the feature of the iris 103 in the first image 51. The method for detecting the feature of the iris 103 is not particularly limited, and a known technique related to iris pattern matching can be used. In the present embodiment, as shown in FIG. 3C, only the portion of the iris 103 is extracted from the image 53 of the entire eye, and the feature of the iris 103 is recognized as a specific pattern using a specific algorithm or the like.

  Further, orientation information is set in the first image 51 before or after the feature (specific pattern) of the obtained iris 103 is detected. Then, the orientation information acquisition unit 44 of the first association unit 31 acquires the orientation information and associates the orientation information with the first image 51. The method for setting the azimuth information is not particularly limited, but in this embodiment, as shown in FIG. 3A, a site having a feature in the eye peripheral region 100 corresponds to the azimuth that can be recognized by the observer. Is used to set an azimuth that can be recognized by the observer, and azimuth information is associated with the first image 51.

  With reference to Fig.3 (a), the case where an up-down and right-left direction is set on an image as an azimuth | direction which an observer can recognize is described. That is, when facing the subject, the subject's head direction is up and the foot direction is down, the subject's right hand side is left and the left hand side is right. When setting the up / down / left / right direction to the first image 51, in the eye peripheral region 100 of the first image 51, eyebrows, upper eyelid (upper eyelash), and lower eyelid (lower eyelash) which are features corresponding mainly to the up-down direction. The vertical direction can be set by recognizing each part such as eyelashes. In addition, the left-right direction can be set by recognizing each part such as the eye (inner eye angle), the corner of the eye (outer eye angle), and the nasal muscles, which is a feature mainly corresponding to the left-right direction. The method for recognizing the characteristics of each part is not particularly limited, and a known method such as image recognition may be used.

  In FIG.3 (b), the upper eyelid 105 and the eyelash 106 are recognized as the characteristic (C1) mainly regarding an up-down direction. Further, the internal eye angle 107 is recognized mainly as a feature (C2) related to the left-right direction. Based on such characteristics, as shown in FIG. 3D, the azimuth information (vertical and horizontal directions) can be set in the first image 51. Further, as shown in FIG. 3C, since the feature of the iris 103 is detected in the first image 51, an image 54 in which the orientation information is associated with the feature of the iris 103 is obtained.

  Note that it is not necessary to recognize features in both the vertical direction and the horizontal direction. Either one can be recognized and the direction perpendicular to that direction can be set as the other direction. Alternatively, the observer may recognize and manually set the orientation information.

(Second image acquisition unit 42)
On the other hand, when imaged using the second optical system 12, the imaged image is sent to the second image acquisition unit 42 and an image including the anterior chamber corner 104 and the iris 103 (second image 61) is generated. Is done. In FIG. 4A, an observation image of the entire periphery of the anterior chamber corner 104 is obtained and an observation image of the entire periphery of the iris 103 is also obtained. The second image 61 can be displayed on the display unit 22 as necessary. As with the first image 51, the feature detection unit 43 detects the feature of the iris 103 in the generated second image 61. Since the iris 103 in the first image 51 and the iris 103 in the second image 61 are images of the same iris, the detected features are also the same.

(Second association unit 32)
Subsequently, the first image 54 (FIG. 4B) having the azimuth information (vertical and horizontal directions) obtained by the azimuth information acquisition unit 44, and the second image 61 (FIG. a)) is compared in the image comparison unit 45 of the second association unit 32. The image comparison unit 45 can match the first image 54 and the second image 61 by collating the features of the iris 103 detected in both images. As a result, as shown in FIG. 4C, the azimuth information of the first image 54 based on the feature of the iris 103 is associated with the second image 61. That is, the azimuth information is associated with the image of the anterior chamber corner angle 104 included in the second image 61.

  As a specific example, when only the second image 61 including the anterior chamber corner 104 is obtained, the white triangle mark 90 is in the position shown in FIG. It is unknown whether it corresponds to the direction of However, as described above, by comparing the first image 54 and the second image 61, the third image 62 in which the azimuth information is associated with the second image 61 is generated. As a result, in the actual orientation in the third image 62 (the orientation that can be recognized by the observer), the white triangle mark 90 shown in FIG. 4A is the same as that in FIG. It can be seen that the image exists at a position rotated by 30 ° clockwise compared to the image 61).

  Therefore, if the white triangle mark 90 is an abnormal part at the anterior chamber corner angle 104, the actual orientation is determined even if the white triangle mark 90 (abnormal part) is observed based on the orientation on the second image 61. Then, since it exists in the place shown in the 3rd image 62 of FIG.4 (c), it is thought that the white triangle mark 90 may not be discovered. Or even if it can be found, it will take time to find it.

  On the other hand, in the present embodiment, by utilizing the feature of the iris 103 common to the first image 54 and the second image 61, an actual orientation (observation) is applied to the image of the anterior chamber corner 104 where orientation information is missing. Orientation that can be recognized by a person). That is, since the azimuth on the third image 62 obtained by the comparison between the first image 54 and the second image 61 corresponds to the actual azimuth, any anterior chamber angle 104 in the third image 62 can be determined. It can be easily understood which place corresponds to the actual orientation, and the white triangle mark 90 (abnormal part) can be observed immediately. In addition, it becomes easy to enlarge and observe only the vicinity of the abnormal part.

  At this time, the processing unit 21 displays the image displayed on the display unit 22 so that the orientation on the image displayed on the display unit 22 matches the orientation information associated with the image obtained by the association unit. It preferably has a correction function.

  In addition, the processing unit 21 may have a function of superimposing and displaying an arbitrary place, a mark indicating an orientation, and the like on the third image 62 using the operation unit 24.

(3. Effects of the present embodiment)
According to the present embodiment, the azimuth information that can be easily recognized by the observer can be associated with the observation image of the anterior chamber corner angle 104 in which the azimuth information is missing. Therefore, the observation location of the anterior chamber corner 104 can be easily identified. In particular, when the entire circumference or wide area of the anterior chamber corner 104 is observed, it is easy to understand how an arbitrary location of the anterior chamber corner 104 in the image corresponds to the actual orientation. can do. Therefore, for example, even when an abnormal site is found at the anterior chamber corner angle 104 in image diagnosis after the end of observation, or when periodic observation is performed, abnormalities are detected based on observation images already associated with orientation information. It is possible to immediately specify a site or a site observed before. In addition, an arbitrary place can be specified regardless of whether the image obtained by the angle mirror is an erect image or an inverted image.

  In the present embodiment, the feature of the iris 103 is used to associate the orientation information with the image of the anterior chamber corner 104. Specifically, an image (first image 51) including a part (eyelid 105, inner eye angle 107, etc.) having a feature corresponding to an orientation that can be recognized by the observer in the eye peripheral region 100 and the iris 103, and the front An image (second image 61) including the bunch corner 104 and the iris 103 is acquired, and first, azimuth information is associated with the iris 103 in the first image 51 using the positional relationship of the part having the feature. . Then, the features of the iris 103 common to the first image 54 and the second image 61 associated with the azimuth information are collated, and the first image 54 and the second image 61 are made to correspond to each other. Orientation information can be easily associated with the 104 images.

  Further, by having a function of correcting the display of the image displayed on the display unit so that the direction on the image displayed on the display unit 22 matches the direction information associated with the image obtained by the association unit. Since the orientation of the image displayed on the display unit can be kept constant, observation of the observation site becomes easier.

  By superimposing and displaying a mark indicating an arbitrary place on an image (third image 62) in which azimuth information is associated with the second image 61, the location of the anterior chamber corner 104 can be more easily recognized.

(4. Modifications etc.)
In the above embodiment, the feature of the eye peripheral region is recognized and the orientation information is associated with the feature of the iris 103 in the first image 51, but the observer manually selects the feature of the iris 103 in the first image 51. Orientation information may be associated.

  Specifically, a mark or the like indicating the orientation of the imaging unit 10 is displayed in advance on the display unit 22 or the finder of the imaging unit 10, and the observer marks the orientation of the display unit and the orientation on the image during observation. And correspond. In other words, when the upper, lower, left, and right marks are displayed on the display unit or the like, the observer may adjust the image so that the marks coincide with the actual orientation. In this way, the orientation (actual orientation) that can be recognized by the observer is set as orientation information in the first image 51 and can be associated with the feature of the iris 103.

  When the mark and the actual orientation are aligned, the observer may make adjustments by moving the image pickup unit 10, or the observer moves the optical system or the image pickup device by driving means through the operation unit 24 for adjustment. May be.

  In the above embodiment, the first image 51 and the second image 61 including the entire circumference of the iris 103 are acquired, the feature of the iris 103 is detected, and the orientation information is displayed at the anterior chamber corner angle 104 in the second image 61. It is related. However, even when the first image including the entire periphery of the iris 103 and the second image 61 including a part of the iris 103 are acquired, the characteristics of the iris 103 in the first image 51 and the second image By collating with the feature of the iris 103 in 61, the azimuth information can be related to the anterior chamber corner 104. In this way, the feature of the iris 103 is associated with the anterior chamber corner 104 in the second image 61 even when a corner mirror that can directly observe only a part of the anterior chamber corner 104 is used. Can do.

  In the above embodiment, the azimuth is set in the up / down / left / right direction of the image. However, coordinates such as an orthogonal coordinate system (xy coordinate system) and a polar coordinate system (rθ coordinate system) are set by setting a reference point (for example, the center of the eye). You may set using a system.

  In the above embodiment, the orientation information is associated with the image of the anterior chamber corner 104 using the feature of the iris 103, but the image of the anterior chamber corner 104 is used using means other than the feature of the iris 103. Orientation information may be associated with.

  For example, this azimuth information can be associated with the image of the anterior chamber corner 104 using azimuth information obtained using an acceleration sensor. In FIG. 5, the schematic block diagram of the ophthalmic observation system 1a in a modification is shown. In this ophthalmic observation system 1 a, the imaging unit 10 includes a second optical system 12 and an imaging element 13. That is, the ophthalmic observation system 1a may not have the first optical system. The acceleration sensor 71 is attached to the imaging unit 10.

  The acceleration sensor 71 can detect the acceleration of the imaging unit 10 that changes according to the movement, shake, etc. of the imaging unit 10 and can detect the vertical direction. This detected vertical direction information can be associated with the image of the anterior chamber corner angle 104. An example in which the azimuth information recognizable by the observer is associated with the image of the anterior chamber angle 104 using the ophthalmic observation system 1a will be described below.

  First, the anterior chamber corner angle of the eye to be examined is imaged using the second optical system 12 of the imaging unit 10. The captured image, that is, the image of the anterior chamber corner is converted into an electrical signal, sent to the image acquisition unit 73 of the processing unit 21, and an image including the anterior chamber angle 104 as shown in FIG. 81 is acquired.

  Further, the change in acceleration detected by the acceleration sensor 71 at the time of imaging is sent to the azimuth detecting unit 74, and the azimuth detecting unit 74 detects the vertical direction based on the change in acceleration. Then, the azimuth information regarding the vertical direction is acquired by the azimuth information acquisition unit 75. Since the vertical direction (arrow 95 in FIG. 6A) indicates the downward direction in the direction that can be recognized by the observer, the vertical direction can be set based on the vertical direction. Also, the direction perpendicular to the vertical direction on the image can be the left-right direction. Therefore, by setting the detected vertical direction to the downward direction, the image generating unit 76 generates an image 82 in which the azimuth information (up / down / left / right direction) is associated with the image 81 of the anterior chamber corner angle 104. Thereby, the effect similar to the effect of embodiment mentioned above can be acquired.

  The detection in the vertical direction will be described with reference to FIG. When the subject's eye is observed when the subject is in the standing or sitting posture, as shown in FIG. 7, the eye peripheral region 100 and the imaging unit 10 (the optical axis of the second optical system (y direction in FIG. 7)). Is substantially perpendicular to the vertical direction (z direction in FIG. 7). At this time, the observation image of the eye to be examined (on the xz plane in FIG. 7) is parallel to the vertical direction (z direction in FIG. 7). Therefore, the vertical direction information obtained by the acceleration sensor can be set for the observation image including the anterior chamber corner angle 104.

DESCRIPTION OF SYMBOLS 1 ... Ophthalmic observation system 10 ... Imaging part 11 ... 1st optical system 12 ... 2nd optical system 20 ... Computer part 21 ... Processing part 31 ... 1st correlation part 43 ... Feature detection part 44 ... Direction information acquisition part 32 ... 1st 2 association unit 45 ... image comparison unit 41 ... first image acquisition unit 42 ... second image acquisition unit 100 ... eye peripheral region 103 ... iris 104 ... anterior chamber corner angle

Claims (6)

First image acquisition means for acquiring a first image obtained by imaging an eye peripheral area having features corresponding to iris and orientation information recognizable by an observer;
A second image obtained by capturing an image of the anterior chamber corner and the iris using a corner mirror capable of directly observing the anterior chamber angle inside the eyeball, wherein the azimuth information is missing. Acquisition means;
Association means for associating azimuth information recognizable by an observer with the image of the anterior chamber corner,
The association means includes
Orientation information acquisition means for acquiring orientation information recognizable by an observer by associating the feature of the iris in the first image acquired by the first image acquisition means with the feature of the eye peripheral region. First association means for associating the orientation information acquired by the orientation information acquisition means with the feature of the iris included in the first image;
By associating the feature of the iris in the first image with the feature of the iris in the second image, the first associating means associates with the feature of the iris included in the first image. Second associating means for associating the azimuth information with the image of the anterior chamber angle included in the second image;
An ophthalmic observation system comprising: The second associating means associates the entire feature of the iris in the first image with which the azimuth information is associated with at least a part of the feature of the iris in the second image, thereby obtaining the azimuth information as the previous information. The ophthalmic observation system according to claim 1 , wherein the ophthalmologic observation system is associated with an entire image of a tuft angle. Using an angle mirror capable of directly observing the anterior chamber angle inside the eyeball, an image obtained by capturing the anterior chamber angle with an imaging unit and lacking azimuth information recognizable by the observer is acquired. Image acquisition means;
An acceleration sensor that is attached to the imaging unit and detects an acceleration that changes according to the movement of the imaging unit;
The azimuth information acquisition unit includes a azimuth information acquisition unit that detects a vertical direction based on a change in acceleration detected by the acceleration sensor and acquires azimuth information in the vertical and horizontal directions based on the detected vertical direction. An association means for associating the orientation information acquired by the image with the anterior chamber corner angle acquired by the image acquisition means;
An ophthalmic observation system comprising: The azimuth information acquisition means acquires azimuth information in the vertical and horizontal directions when the observer faces the subject as an azimuth recognizable by the observer. The ophthalmic observation system described. Display means for displaying an image of the anterior chamber corner;
The orientation of the image displayed on the display means, so as to coincide with the associated means by bearing information associated with the image of the anterior chamber angle, to correct the display of an image displayed on the display means The ophthalmic observation system according to any one of claims 1 to 4 . The ophthalmic observation system according to any one of claims 1 to 5 , further comprising a function of superimposing and displaying a mark indicating an arbitrary place on an image obtained by the association means.

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