Apparatus, method, and system for evaluating exophthalmos used in an exophthalmos inspection device

Abstract

The present invention relates to an apparatus and method for evaluating the degree of exophthalmos used in an exophthalmos inspection apparatus. The apparatus includes a left displacement platform, a left eye corner locking point, a left mirror, a camera, a near-infrared light source, a right eye corner locking point, a right mirror, a right displacement platform, a visible light beam column, and a housing. The method includes adjusting and fixing the outer corner point of the eye, controlling the near-infrared light source to sequentially turn on multiple columns of visible light beam columns, capturing and obtaining a front view video of the eyeball by a camera, and obtaining a video frame when the longest reflected light of the visible light beam column appears on the eyeball in the mirror from the video; identifying the corneal apex from the video frame and identifying the pupil center using a neural network; and calculating the degree of exophthalmos based on a known position, a mirror tilt angle, the corneal apex, and the pupil center.

Description

Technical Field

[0001] The present invention relates to the technical field of eye detection, and specifically, to an apparatus, method, and system for evaluating the degree of proptosis used in a proptosis inspection apparatus.

Background Art

[0002] The degree of proptosis refers to the distance from the apex of the corneal vertex of the eyeball to the orbital margin of the temporal bone. The average value of the degree of proptosis in healthy individuals is 12 - 14 mm, with an average of 13 mm, and the difference between both eyes does not exceed 2 mm. Patients with orbital diseases often experience an increase in the degree of proptosis. Currently, clinically, for measuring the degree of proptosis, mainly the Hertel exophthalmometer and the CT scan measurement method are used.

[0003] The Hertel exophthalmometer belongs to contact measurement, and it is necessary to manually record the readings during the experimental process. The evaluation results between individuals are closely related to the experience of the diagnosing physician and the measurement method, which are likely to cause individual differences. The patient comes into close contact with the physician, increasing the risk of infection for the subject and the detector in the complex clinical diagnosis and treatment environment. Also, according to research, when detecting using the Hertel exophthalmometer, since the lateral orbital margins are not completely symmetrical and the degree of soft tissue sinking is different, there are no unified application criteria and operation rules related to the visual errors and experience of the examiner, resulting in an obvious difference in the reading values of different examiners. It is considered that the reading values of experienced detectors are 1 mm larger than those of inexperienced observers. CT scan measurement is more accurate than the Hertel exophthalmometer measurement method, but it has problems such as high radiation, high measurement cost, and slow result generation.

[0004] In response to the problem that the accuracy of the above method is low or the cost is high, there are also technical means in the prior art to determine the exophthalmos using an automatic measuring device and method. As described in Chinese Patent CN104720738A (Application No.: 201510155640.4, Publication Date: June 24, 2015), the first distance X1 in the front-rear direction from the system reference point St of the ophthalmic device to the outer edge Ek of the human eye socket, the second distance X2 in the front-rear direction from the system probe of the ophthalmic device to the system reference point St, and the third distance X3 in the front-rear direction from the corneal apex Ec to the system probe are obtained, and the exophthalmos is obtained using X1 + X2 - X3. As described in Chinese Patent CN112806956A (Application No.: 202110139034.9, Publication Date: May 18, 2021), the distance measuring sensor is used to move on the driving member to identify the corneal apex, and the distance between the light emitter and the distance measuring sensor is obtained to determine the exophthalmos. All of the above methods have the disadvantages that the device is complex and the identification of the corneal apex is inaccurate.

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to solve the problems of large error and high cost in the measurement of exophthalmos in the prior art, the present invention provides an exophthalmos evaluation device, method and system used in an exophthalmos examination device for improving the accuracy of the measurement of exophthalmos.

Means for Solving the Problems

[0006] The exophthalmos evaluation device used in the exophthalmos examination device according to the first aspect of the present invention is It includes a left displacement platform, a left canthus locking point, a left mirror, a camera, a near-infrared light source, a right canthus locking point, a right mirror, a right displacement platform, a visible light beam column, and a housing. The left mirror and the right mirror are respectively provided at the left canthus locking point and the right canthus locking point. The left canthus locking point and the right canthus locking point are respectively provided on the left displacement platform and the right displacement platform. The left displacement platform and the right displacement platform are respectively provided on both sides of the housing. The left mirror and the right mirror are both provided obliquely. The camera is located in front of the left mirror and the right mirror. The near-infrared light source is located below the camera. The visible light beam columns are in multiple rows and are arranged vertically along the inside of the housing.

[0007] Furthermore, the two cameras are respectively provided to be located in front of the left mirror and the right mirror.

[0008] Furthermore, each row of the visible light beam columns is composed of discrete point light sources.

[0009] The method for evaluating the degree of exophthalmos according to the second aspect of the present invention, using the device for evaluating the degree of exophthalmos used in the exophthalmos inspection device according to the first aspect of the present invention, Adjust and fix the outer corner point of the canthus, control the near-infrared light source to sequentially turn on multiple rows of visible light beam columns, capture and obtain a frontal video of the eyeball by the camera, and obtain the video frame when the longest reflected light of the visible light beam column appears on the eyeball in the mirror from the video in step S1; Identify the corneal apex from the video frame and identify the pupil center using a neural network in step S2; It includes step S3 of calculating the degree of exophthalmos based on the known position, the mirror tilt angle, the corneal apex, and the pupil center. The known position is the position of the optical center of the camera, the distance from the optical center of the camera to the video frame, and the position of the outer corner point of the canthus. The mirror tilt angle is the included angle between the mirror and the imaging plane.

[0010] Furthermore, in the step S1, the step of sequentially lighting the plurality of visible light columns means lighting them in order from the center to the outside or from the outside to the center.

[0011] Furthermore, in the step S1, when one side of the visible light column is lit, a video of the opposite eye is taken.

[0012] Furthermore, in the step S3, the optical center is O, the outer corner of the eye is E, the distance from the optical center O to the video frame is OB, the imaging point of the corneal apex Z in the video frame is C, the imaging point of the reflection point U of the corneal apex Z on the mirror in the video frame is A, the perpendicular distances from the imaging point C and the imaging point A to the optical axis are AB and CB respectively, the inclination angle between the mirror and the eye is ∠UED, the distance from the optical center O to the face plane where the outer corner of the eye E is located is OF, the distance from the outer corner of the eye E to the optical axis is EF, the exophthalmos is the perpendicular distance ZG from the corneal apex Z to the straight line DE, and the lengths of OB, OF, EF, AB, CB and the angle of ∠UED are known. The step of calculating the exophthalmos is Step S31 of passing a straight line parallel to the straight line DE through the reflection point U of the corneal apex Z on the mirror, intersecting the optical axis at point W, intersecting ZG at point Y, and intersecting the extension line of the straight line OC at point X respectively; Step S32 of obtaining the length of the line segment WF by the following formula; WF=(OFtan∠UOW - EF) / (tan∠UOW + 1 / (tan∠UED)) Step S33 of obtaining the length of the line segment ZY by iterative calculation; Step S34 of obtaining the exophthalmos according to ZG = WF + ZY, is included.

[0013] An evaluation system for realizing the exophthalmos evaluation method of the second aspect of the present invention according to another aspect of the present invention is A video collection module that collects a front view video of the eyeball when a plurality of visible light columns of a near-infrared light source are sequentially lit; An image acquisition module that acquires the video frame with the longest reflected light of the visible light light column in the mirror from the video; A feature extraction module that extracts the corneal apex and pupil center from the video frame; A calculation module that calculates the exophthalmos based on a known position, a mirror tilt angle, the corneal apex, and the pupil center, where the known position is the position of the optical center of the camera, the distance from the optical center of the camera to the video frame, and the position of the outer corner of the eye, and the mirror tilt angle is the included angle between the mirror and the imaging surface.

[0014] A computer-readable storage medium according to another aspect of the present invention stores at least one program code that is loaded by a processor and executes the method for evaluating exophthalmos according to the second aspect of the present invention.

Advantages of the Invention

[0015] The technical means of the present invention has at least the following beneficial effects compared with the prior art.

[0016] The evaluation device captures an eye video in the near-infrared light field and uses a neural network to effectively distinguish the iris, pupil, and sclera, thereby accurately identifying the pupil center. By providing a series of vertical visible light light columns around the user's face, the visible light light columns are lit in sequence to find the longest reflected light of the visible light light column appearing on the eye in the mirror, and the corneal apex can be accurately and simply identified. After identifying the pupil center and corneal apex, by combining the known position and the mirror tilt angle and using the algorithm in the present invention based on the optical imaging principle, the exophthalmos can be accurately calculated without contacting the cornea, thereby ensuring the accuracy and safety of the measurement of exophthalmos.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying out the Invention

[0018] Hereinafter, with reference to the drawings and examples, specific embodiments of the present invention will be described in more detail. The following examples are for explaining the present invention and do not limit the scope of the present invention.

[0019] In the present invention, OB, AB, CB, EF, etc. used in the calculation all refer to the lengths of line segments.

[0020] (Example 1) As shown in FIG. 1, the exophthalmos evaluation device used in the exophthalmos inspection device according to this embodiment includes a left displacement platform 3, a left eye corner locking point 4, a left mirror 5, a camera 8, a near-infrared light source 9, a right eye corner locking point 10, a right mirror 11, a right displacement platform 12, a visible light column 13, and a housing 14. The left mirror 5 and the right mirror 11 are respectively provided at the left eye corner locking point 4 and the right eye corner locking point 10. The left eye corner locking point 4 and the right eye corner locking point 10 are respectively provided on the left displacement platform 3 and the right displacement platform 12. The left displacement platform 3 and the right displacement platform 12 are respectively provided on both sides of the housing 14. The left mirror 5 and the right mirror 11 are both provided obliquely. The camera 8 is located in front of the left mirror 5 and the right mirror 11. The near-infrared light source 9 is located below the camera 8. The visible light columns 13 are in multiple rows and are arranged vertically along the inside of the housing 14.

[0021] To further support and adjust the evaluation device and ensure the fixation of the evaluation device to the user, the evaluation device further includes a lower support frame 1, a tray 2, a forehead rest 6, and an upper support frame 7. The lower support frame 1 and the upper support frame 7 are respectively located at the lower and upper parts of the housing 14, supporting and rotating the entire evaluation device, and the tray 2 and the forehead rest 6 fix the user.

[0022] Furthermore, the two cameras 8 are respectively provided in front of the left mirror 5 and the right mirror 11 to capture videos of the left and right eyes respectively. To provide a uniform near-infrared light field, a plurality of near-infrared light sources 9 may be provided as light sources, uniformly distributed below the cameras 8, and each visible light column 13 in the vertical direction may be provided as an array composed of point light sources and wrapped with silica gel on the outside.

[0023] When measuring the exophthalmos using the above device, first, adjust the left displacement platform 3 and the right displacement platform 12, and use the left eye corner locking point 4 and the right eye corner locking point 10 to fix the outer corner points of both eyes of the user to adapt to the facial features of different users. After fixing both eyes and the face of the user, turn on the near-infrared light source 9, and then turn on a series of visible light columns 13 provided vertically from the center to the outside or from the outside to the center in sequence. The visible light columns 13 form reflected lights with different lengths on the eyeballs in the mirrors in sequence, and it is possible to find the video frame in which the visible light column 13 forms the longest projection on the cornea from the captured video. The projection passes through the corneal apex, and the pupil center can be accurately found using neural network analysis from the video frame captured in the light field of the near-infrared light source 9. Using the corneal apex and the pupil center, the exophthalmos is obtained by combining parameters such as known distances and mirror tilt angles.

[0024] (Embodiment 2) As shown in FIGS. 2 and 3, this embodiment provides a method for evaluating exophthalmos, and will be described below in combination with the evaluation device for exophthalmos used in the exophthalmos examination device. The method for evaluating exophthalmos includes the following steps S1 to S3.

[0025] In step S1, the outer corner of the eye is adjusted and fixed, the near-infrared light source is controlled to sequentially turn on multiple columns of visible light beams, a frontal video of the eyeball is captured and obtained by a camera, and a video frame is obtained from the video when the longest reflected light of the visible light beam appears on the eyeball in the mirror. In the above step S1, when the visible light beam in the vertical direction on one side is turned on, the video of the eye on the opposite side is captured. Specifically, when the left visible light beam 13 is turned on, the video of the right eye is captured, and when the right visible light beam 13 is turned on, the video of the left eye is captured. Since a series of vertical visible light beams 13 are provided and the left mirror 5 and the right mirror 11 are provided in an inclined manner, by sequentially turning on the visible light beams 13 from the outside to the inside, the visible light beams 13 exhibit a series of reflected lights with different lengths on the side of the eyeball in the mirror, and the longest projection of the visible light beam 13 on the cornea can be found by the reflected light of the eye in the mirror. For example, when the rightmost visible light beam 13 is turned on, the reflected light of the light beam on the side of the eyeball in the left mirror 5 of the left eye approaches the inner corner point of the eye. When the turned-on visible light beam 13 gradually moves inward, the reflected light of the light beam on the side of the eyeball in the left mirror 5 gradually becomes longer until it passes through the corneal apex. At this time, the reflected light is the longest, and the video frame at this time is obtained from the video.

[0026] In step S2, the corneal apex is specified from the video frame, and the pupil center is specified using a neural network. As shown in FIG. 3, the corneal apex can be identified by the video frame with the longest reflected light from the eyeball in the mirror, and the corneal apex is the contact point between the reflected light from the eyeball in the left mirror in FIG. 3 and the perpendicular line. In the wavelength band of normal visible light of 400-700 nm, the colors of different parts of the eye, namely the pupil, iris, and sclera, have little effect on imaging, and due to the gradient structure of the corneal limbus at the contact part between the iris and the sclera, the center of the eyeball cannot be accurately identified. Human melanin pigment has an absorption peak at about 335 nm and is hardly absorbed at all in the wavelength band exceeding 700 nm. Since the reflectance of the iris is quite stable within the near-infrared band exceeding 700 nm, the present invention can clearly distinguish the sclera, iris, and pupil boundary by using a near-infrared light field, and can accurately identify the pupil center in combination with a neural network training model. In one possible implementation form, this embodiment uses the RITNet neural network model.

[0027] The apparatus for evaluating the degree of exophthalmos used in the exophthalmos inspection apparatus according to Embodiment 1 further provides a function of identifying the pupil center by manual operation after identifying the corneal apex from the video frame, and the user can select to use the neural network or manual operation as needed to identify the pupil center.

[0028] In step S3, the degree of exophthalmos is calculated based on the known position, the mirror tilt angle, the corneal apex, and the pupil center.

[0029] In the above step S3, the known position is the position of the optical center of the camera, the distance from the optical center of the camera to the video frame, and the position of the outer corner of the eye. The mirror tilt angle is the included angle between the mirror and the imaging plane. The distance can be obtained from the known position, and this distance refers to the distance from the optical center of the camera to the imaging plane (i.e., the photoreceptor), which is called the image distance in photography. The degree of exophthalmos can be obtained by combining the above-mentioned distance, the mirror tilt angle, and the imaging points of the pupil center and the corneal apex in the video frame.

[0030] (Example 3) Based on Example 2 of the above method, this Example 3 further describes a method for mathematically calculating the exophthalmos degree.

[0031] As shown in Figure 4, the optical center is O, the outer corner of the eye's canthus point is E, the vertical distance from the optical center O to the video frame is OB, the imaging point of the corneal apex Z on the video frame is C, the imaging point of the reflection point U of the corneal apex Z on the mirror on the video frame is A, the vertical distances from the imaging point C and the imaging point A to the optical axis are AB and CB respectively, the inclination angle between the mirror and the eye is ∠UED, the distance from the optical center O to the face plane where the outer corner of the eye's canthus point E is located is OF, the distance from the outer corner of the eye's canthus point E to the optical axis is EF, the exophthalmos degree is the vertical distance ZG from the corneal apex Z to the straight line DE, and the lengths of OB, OF, EF, AB, CB and the angle of ∠UED are known. The steps for calculating the exophthalmos degree include the following steps S31 to S33.

[0032] In step S31, a straight line parallel to the straight line DE passing through the reflection point U of the corneal apex Z on the mirror intersects the optical axis at point W, intersects ZG at point Y, and intersects the extension line of the straight line OC at point X respectively.

[0033] As can be seen from the imaging principle, there is an imaging point C of the corneal apex Z on the captured video frame, and there is also an imaging point A of the reflection point U of the corneal apex Z on the mirror. In the video frame, the distances CB and AB from the imaging point C and the imaging point A to the optical axis can be read. As can be seen from the light reflection principle, the incident angle of the corneal apex Z on the mirror is equal to the reflection angle, that is,

Equation

Equation

[0034] In step S32, the lengths of OB, OF, AB, CB, EF and the magnitude of ∠UED are known, and the following can be obtained from analytical geometry relationships.

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[0035] The following can be obtained from analytical geometry relationships.

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[0036] In step S34, the exophthalmos is set as the distance ZG from the corneal apex Z to the straight line DE.

[0037] ZG = WF + ZY(9) Calculate the exophthalmos degree according to formula (4) and formula (8).

[0038] Thus, in order to calculate the exophthalmos degree, first, it is necessary to calculate the lengths of line segment YG and line segment ZY in FIG. 4. Since the length of line segment YG is equal to the length of line segment WF, the exophthalmos degree can be obtained by the sum of the distances of line segment WF and line segment ZY.

[0039] In step S32, by solving the three-variable linear equation of formula (3), the length of line segment WF and the distance of line segment UX can be obtained. In step S33, first, assume that UY is equal to UX, that is, YX is equal to zero. At this time, using trigonometric functions, the estimated value of ZY, that is

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[0040] In the above calculation process, automatic calculation can be realized by a computer program, obtaining the video frame with the longest reflected light on the mirror of the visible light column, and only by inputting it into the computer, the result of the exophthalmos can be automatically output.

[0041] (Example 4) FIG. 5 is a schematic configuration diagram of an exophthalmos evaluation system according to an embodiment of the present invention. As shown in FIG. 5, the system includes a video acquisition module 501 that acquires a video of the frontal view of the eyeball when a plurality of visible light columns of a near-infrared light source are sequentially lit, an image acquisition module 502 that acquires the video frame with the longest reflected light on the mirror of the visible light column from the acquired video, a feature extraction module 503 that identifies the corneal apex from the video frame acquired by the image acquisition module and extracts the pupil center using a neural network, a calculation module 504 that calculates the exophthalmos based on the parameters of the known position, mirror tilt angle, corneal apex, and pupil center. The known position includes the position of the optical center of the camera, the distance from the optical center of the camera to the video frame, and the position of the outer corner of the eye. The mirror tilt angle is the included angle between the mirror and the imaging surface.

[0042] In an exemplary embodiment, there is further provided a computer-readable storage medium including a memory in which at least one program code is stored, which is loaded and executed by a processor to implement the exophthalmos evaluation method in the above embodiment. For example, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CDROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0043] A person skilled in the art would understand that the implementation of all or part of the steps in the above embodiments may be completed by hardware, or may be completed by hardware related to at least one program code. The program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disk, or the like.

[0044] The above are only preferred embodiments of the present invention and do not limit the present invention. All modifications, equivalent substitutions, and improvements made within the concept and principles of the present invention should be included within the protection scope of the present invention.

Explanation of Reference Numerals

[0045] 1 Lower support frame 2 Tray 3 Left displacement platform 4 Left eye corner locking point 5 Left mirror 6 Forehead rest 7 Upper support frame 8 Camera 9 Near-infrared light source 10 Right eye corner locking point 11 Right mirror 12 Right displacement platform 13 Visible light light column 14 Housing 501 Video collection module 502 Image acquisition module 503 Feature extraction module 504 Calculation module

Claims

1. It includes a left displacement platform (3), a left eye corner locking point (4), a left mirror (5), a camera (8), a near-infrared light source (9), a right eye corner locking point (10), a right mirror (11), a right displacement platform (12), a visible light light column (13), and a housing (14), The left mirror (5) and the right mirror (11) are respectively provided at the left eye corner locking point (4) and the right eye corner locking point (10), The left eye corner locking point (4) and the right eye corner locking point (10) are respectively provided on the left displacement platform (3) and the right displacement platform (12), The left displacement platform (3) and the right displacement platform (12) are respectively provided on both sides of the housing (14), Both the left mirror (5) and the right mirror (11) are provided obliquely, The camera (8) is located in front of the left mirror (5) and the right mirror (11), The near-infrared light source (9) is located below the camera (8), The visible light light columns (13) are in multiple rows and are arranged vertically along the inside of the housing (14), It is an evaluation device for the degree of exophthalmos used in an exophthalmos inspection device, characterized in that.

2. The two cameras (8) are respectively provided so as to be located in front of the left mirror (5) and the right mirror (11), It is an evaluation device for the degree of exophthalmos using the exophthalmos inspection device according to Claim 1, characterized in that.

3. Each row of the visible light light columns (13) is composed of discrete point light sources, It is an evaluation device for the degree of exophthalmos used in the exophthalmos inspection device according to Claim 1, characterized in that.

4. It is an evaluation method for the degree of exophthalmos using the evaluation device for the degree of exophthalmos used in the exophthalmos inspection device according to any one of Claims 1 to 3, Adjust and fix the outer corner point of the eye corner, control the near-infrared light source to sequentially light multiple rows of visible light light columns, capture and obtain a front view video of the eyeball by the camera, and obtain the video frame when the longest reflected light of the visible light light column appears on the eyeball in the mirror from the video in step S1, Determine the corneal apex from the video frame and identify the pupil center using a neural network in step S2, It includes step S3 of calculating the degree of exophthalmos based on the known position, the mirror tilt angle, the corneal apex, and the pupil center, The known position is the position of the optical center of the camera, the distance from the optical center of the camera to the video frame, and the position of the outer corner point of the eye corner, The mirror tilt angle is the angle between the mirror and the imaging plane, which is a method for evaluating the degree of exophthalmos.

5. In step S1, lighting the plurality of visible light columns in sequence means lighting them in sequence from the center to the outside or from the outside to the center. The method for evaluating the degree of exophthalmos according to claim 4, characterized in that.

6. In step S1, when the visible light column on one side is lit, a video of the eye on the opposite side is taken. The method for evaluating the degree of exophthalmos according to claim 5, characterized in that.

7. In step S3, the optical center is O, the outer corner point of the eye corner is E, the distance from the optical center O to the video frame is OB, the imaging point of the corneal apex Z in the video frame is C, the imaging point of the reflection point U of the corneal apex Z on the mirror in the video frame is A, the perpendicular distances from the imaging point C and the imaging point A to the optical axis are AB and CB respectively, the tilt angle between the mirror and the eye is ∠UED, the distance from the optical center O to the face plane where the outer corner point E of the eye corner is located is OF, the distance from the outer corner point E of the eye corner to the optical axis is EF, the degree of exophthalmos is the perpendicular distance ZG from the corneal apex Z to the straight line DE, the lengths of OB, OF, EF, AB, CB and the angle of ∠UED are known, The steps for calculating the degree of exophthalmos are Step S31 of passing a straight line parallel to the straight line DE through the reflection point U of the corneal apex Z on the mirror, intersecting the optical axis at point W, intersecting ZG at point Y, and intersecting the extension line of the straight line OC at point X respectively, Step S32 of obtaining the length of the line segment WF by the following formula, 【Number 1】 Step S33 of obtaining the length of the line segment ZY by iterative calculation, including step S34 of obtaining the degree of exophthalmos according to ZG = WF + ZY. The method for evaluating the degree of exophthalmos according to claim 4, characterized in that.

8. An evaluation system for realizing the method for evaluating the degree of exophthalmos according to any one of claims 4 to 7, a video collection module for collecting a video of the front view of the eyeball when a plurality of visible light columns of a near-infrared light source are lit in sequence, an image acquisition module for obtaining the video frame with the longest reflected light of the visible light column on the mirror from the video, a feature extraction module for extracting the corneal apex and the pupil center from the video frame, and a calculation module for calculating the degree of exophthalmos based on the known position, the mirror tilt angle, the corneal apex, and the pupil center. The known positions are the position of the optical center of the camera, the distance from the optical center of the camera to the video frame, and the position of the outer corner point of the eye corner, The mirror tilt angle is the included angle between the mirror and the imaging surface, An evaluation system characterized by the above.

9. At least one program code that is loaded by a processor and executes the method for evaluating the exophthalmos according to any one of Claims 4 to 7 is stored, A computer-readable storage medium characterized by the above.

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