Ophthalmic information processing device, ophthalmic device, ophthalmic information processing method, and program

Abstract

This ophthalmic information processing device includes a data acquisition unit and a computation image generation unit. The data acquisition unit acquires image data for two or more fundus images obtained by irradiating the fundus of an eye under examination with two or more lights. The computation image generation unit generates a computation image by performing an image comparison process on the two or more fundus images on the basis of the image data for the two or more fundus images.

Description

Ophthalmological information processing device, ophthalmological device, ophthalmological information processing method, and program

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 638,703, entitled "OPHTHALMIC APPARATUS," filed April 25, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to an ophthalmological information processing device, an ophthalmological apparatus, an ophthalmological information processing method, and a program.

[0003] Evaluation of circulatory dynamics in the fundus is effective in understanding the pathology of ocular fundus diseases. To understand such circulatory dynamics in the fundus, fluorescein angiography (FA), indocyanine green angiography (ICGA), and / or optical coherence tomography (OCT) are generally used.

[0004] Patent Documents 1 and 2 disclose a method for obtaining a fluorescent contrast image of the fundus using FA or ICGA by intravenously injecting a contrast agent.

[0005] Non-Patent Document 1 discloses a method for generating a choroidal vascular image by performing software processing on a fluorescent contrast image acquired using ICGA and a frontal fundus image acquired using red light.

[0006] Patent Document 3 discloses a technique for acquiring a subretinal angiographic image using three-dimensional OCT volume information acquired by performing a three-dimensional OCT scan on the fundus.

[0007] Japanese Patent Application Laid-Open No. 2023-150196 Japanese Patent Application Laid-Open No. 2023-535245 Japanese Patent Application Laid-Open No. 2016-202900

[0008] Naoko Kakiuchi et al. , “Choroidal Vasculature from Ultra-Widefield Images without Contrast Dye and Its Application to Vogt-Koyanagi-Harada Disease”, American Academy of Ophthalmology, Vol. 3. No. 2, February 2019, pp. 161-169

[0009] FA and ICGA require the use of contrast agents, which increases the burden on the subject. Furthermore, OCT techniques require three-dimensional scanning, which increases the scan time and burden on the subject. Furthermore, because the scan range is narrow, attempting to obtain an angiographic image in a desired imaging range increases the scan time and burden on the subject.

[0010] Furthermore, the technique disclosed in Non-Patent Document 1 requires obtaining a fluorescent contrast image using ICGA and a frontal fundus image, and it is not possible to easily obtain an image that shows the structure of the fundus.

[0011] The present invention has been made in consideration of the above circumstances, and one of its purposes is to provide a new technology for easily obtaining images representing the structure of the fundus without imposing a burden on the subject.

[0012] One aspect of the embodiment includes a data acquisition unit and a calculated image generation unit. The data acquisition unit acquires image data of two or more fundus images obtained by irradiating the fundus of the subject's eye with two or more lights. The calculated image generation unit generates a calculated image by performing image comparison processing on the two or more fundus images based on the image data of the two or more fundus images.

[0013] According to the present invention, it is possible to provide a new technique for easily acquiring an image showing the structure of the fundus without imposing a burden on the subject.

[0014] FIG. 1 is a schematic diagram showing an example of the configuration of an optical system of an ophthalmic apparatus according to an embodiment. FIG. 1 is a schematic diagram showing an example of the configuration of an optical system of an ophthalmic apparatus according to an embodiment. FIG. 2 is a schematic diagram showing an example of the configuration of an optical system of an ophthalmic apparatus according to an embodiment. FIG. 3 is a schematic diagram showing an example of the configuration of a processing system of an ophthalmic apparatus according to an embodiment. FIG. 4 is a schematic diagram for explaining the operation of an ophthalmic apparatus according to an embodiment. FIG. 5 is a schematic diagram for explaining the operation of an ophthalmic apparatus according to an embodiment. FIG. 6 is a schematic diagram for explaining the operation of an ophthalmic apparatus according to an embodiment. FIG. 7 is a schematic diagram for explaining the operation of an ophthalmic apparatus according to an embodiment. FIG. 8 is a schematic diagram for explaining the operation of an ophthalmic apparatus according to an embodiment. FIG. 9 is a schematic diagram for explaining the operation of an ophthalmic apparatus according to an embodiment. FIG. 10 is a schematic diagram showing a flow of an example of the operation of an ophthalmic apparatus according to an embodiment. FIG. 11 is a schematic diagram showing an example of the configuration of an ophthalmic apparatus according to a first modified example of an embodiment. FIG. 12 is a schematic diagram showing an example of the configuration of an ophthalmic apparatus according to a second modified example of an embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an ophthalmic apparatus according to a fourth modified example of an embodiment. FIG. 14 is a schematic diagram showing another example of the configuration of an ophthalmic apparatus according to the fourth modified example of an embodiment. FIG. 15 is a schematic diagram for explaining the operation of an ophthalmic apparatus according to a fifth modified example of an embodiment. FIG. 16 is a schematic diagram for explaining the operation of an ophthalmic apparatus according to a fifth modified example of an embodiment. Fig. 10 is a schematic diagram showing an example of the configuration of an ophthalmologic system according to a sixth modified example of an embodiment; Fig. 11 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to a sixth modified example of an embodiment; Fig. 12 is a schematic diagram showing an example of the configuration of an ophthalmologic information processing apparatus according to a sixth modified example of an embodiment; Fig. 13 is a schematic diagram showing an example of the configuration of an ophthalmologic information processing unit according to a sixth modified example of an embodiment.

[0015] The following describes in detail exemplary embodiments of an ophthalmological information processing device, an ophthalmological device, an ophthalmological information processing method, and a program according to the present invention, with reference to the accompanying drawings. Note that the contents of documents cited in this specification and any publicly known techniques may be incorporated into the following exemplary embodiments.

[0016] An ophthalmologic information processing apparatus according to an embodiment acquires image data of two or more fundus images obtained by simultaneously or sequentially irradiating the fundus of a subject's eye (examined eye). Each of the two or more fundus images is a frontal fundus image. The ophthalmologic information processing apparatus is capable of generating a calculated image from the two or more fundus images based on the image data of the acquired two or more fundus images. The calculated image is an image that depicts contrast differences resulting from differences in imaging using two or more lights.

[0017] In some embodiments, an ophthalmologic apparatus is provided outside the ophthalmologic information-processing apparatus according to the embodiment. In this case, the ophthalmologic apparatus is configured to acquire image data of the two or more fundus images. The ophthalmologic information-processing apparatus according to the embodiment is configured to acquire the image data by receiving the image data transmitted by the ophthalmologic apparatus.

[0018] In some embodiments, an ophthalmologic apparatus includes an ophthalmologic information processing apparatus according to an embodiment, in which the ophthalmologic apparatus simultaneously or sequentially irradiates a fundus of a subject's eye (examined eye) with two or more lights to acquire image data of two or more fundus images, and generates a calculated image from the two or more fundus images based on the image data of the acquired two or more fundus images.

[0019] In some embodiments, the two or more lights differ from each other in at least one of their penetration depths into the fundus and their light response characteristics (such as absorption and reflection characteristics). The two or more lights may have different central wavelengths. In some embodiments, the two or more lights are lights of two or more wavelength ranges having different central wavelengths. At least one of the two or more wavelength ranges may partially overlap with another wavelength range. The two or more wavelength ranges may be non-overlapping.

[0020] Examples of wavelength ranges include the wavelength range of visible light, the wavelength range of near-infrared light, etc. The wavelength range of visible light includes the short wavelength range (wavelength range of blue light: for example, 400 nm to 500 nm), the medium wavelength range (wavelength range of green light: for example, 500 to 600 nm), and the long wavelength range (wavelength range of red light: for example, 600 to 700 nm). The wavelength range of near-infrared light is, for example, a wavelength range of 700 nm or more.

[0021] In some embodiments, the central wavelengths of at least two of the two or more lights are within the same wavelength range, for example, the central wavelength of at least a first light and a second light of the two or more lights may be within the wavelength range of blue light, the wavelength range of green light, the wavelength range of red light, or the wavelength range of near-infrared light.

[0022] When the central wavelengths of the two or more lights are different from each other, the calculated image is an image in which contrast resulting from the difference in imaging using lights with different central wavelengths is enhanced. The pixel value of each pixel in the calculated image is obtained by performing a predetermined calculation process (image comparison process) on the pixel values ​​of corresponding pixels in the two or more fundus images. In some embodiments, the calculated image is generated by performing different calculation processes for corresponding pixel regions of the two or more fundus images.

[0023] This makes it possible to acquire a computed image that depicts the distribution of computed values ​​of reflection intensity corresponding to contrast differences caused by differences in imaging, without using a contrast agent or requiring a long scan time.

[0024] Examples of the calculated image according to the embodiment include a difference image, an addition image, a ratio image, a logarithmic image, and an arithmetic operation image. A difference image is obtained by performing a difference process as an image comparison process for each corresponding pixel of two or more fundus images. A addition image is obtained by performing an addition process as an image comparison process for each corresponding pixel of two or more fundus images. A ratio image is obtained by performing a ratio operation process as an image comparison process for each corresponding pixel of two or more fundus images. A logarithmic image is obtained by performing a logarithmic operation process as an image comparison process for each corresponding pixel of two or more fundus images. An arithmetic operation image is obtained by performing an arithmetic operation process as an image comparison process according to a predetermined function for each corresponding pixel of two or more fundus images.

[0025] In some embodiments, the two or more lights are a first light and a second light. The first light is light having a first wavelength as a center wavelength, and the second light is light having a second wavelength as a center wavelength, which is different from the first wavelength in at least one of the penetration depth in the fundus and the light response characteristics. That is, the information processing device according to the embodiment acquires first image data of a first fundus image and second image data of a second fundus image, which are obtained by simultaneously or sequentially irradiating the fundus with the first light and the second light. The first light is light in a first wavelength range with the first wavelength as a center wavelength. The second light is light in a second wavelength range with the second wavelength as a center wavelength. The ophthalmologic information processing device can generate a calculated image by performing an image comparison process on the first fundus image and the second fundus image based on the acquired first image data and second image data. When the calculated image is a difference image, the difference image is an image in which contrast is enhanced by the difference between imaging using light with different center wavelengths.

[0026] In this way, when two or more lights have different central wavelengths, it is possible to obtain a calculated image depicting the distribution of calculated values ​​of reflection intensity for each pixel in a depth range corresponding to at least one of two or more light penetration depths and light reaction characteristics. Therefore, it is possible to easily obtain a front image showing the structure of the fundus in a desired depth range without imposing a burden on the subject.

[0027] In some embodiments, the first wavelength is a wavelength within a wavelength range of near-infrared light, and the second wavelength, which is different from the first wavelength, is a wavelength within the wavelength range of near-infrared light or a wavelength within the wavelength range of red light. This makes it possible to obtain a calculated image having pixel values ​​calculated for each pixel from the first fundus image and the second fundus image in a depth range between the depth position reached by the first light and the depth position reached by the second light. As a result, it is possible to easily obtain a frontal fundus image depicting tissues within the above depth range.

[0028] In some embodiments, the first light is laser light of a first wavelength or light from a light source having a spectral distribution centered on the first wavelength, and in some embodiments, the second light is laser light of a second wavelength or light from a light source having a spectral distribution centered on the second wavelength.

[0029] In this case, it is possible to obtain a calculated image depicting the distribution of the integrated value of the reflection intensity for each pixel in the depth range between the deepest depth position corresponding to the depth of the first light and the deepest depth position corresponding to the depth of the second light, without using contrast agents or requiring long scanning times.

[0030] In some embodiments, the first light is light having a first wavelength in a wavelength range including an absorption peak wavelength of a predetermined site or tissue on the fundus, and the second light is light having a second wavelength different from the first wavelength. Examples of the predetermined site or tissue include choroidal blood vessels, choroidal stroma, sclera, scleral blood vessels, blood vessels in the optic nerve head, and retinal blood vessels. This makes it possible to obtain a calculated image in which the contrast difference resulting from the difference between the absorption peak in the first light and the absorption peak in the second light is emphasized. As a result, it is possible to easily obtain a frontal fundus image depicting the predetermined site or tissue.

[0031] According to any of the above aspects, by acquiring the calculated image for a depth range including the choroid in the fundus, it is possible to easily grasp the structure (vascular diameter, vascular density, number of blood vessels, and course) and symmetry of the choroidal blood vessels. This makes it possible to easily estimate or detect early signs of fundus diseases that appear in the structure of the choroidal blood vessels. Examples of such fundus diseases include age-related macular degeneration, polypoidal choroidal vasculopathy, venous overload choroidopathy, central retinal vein occlusion (CRVO), branch retinal vein occlusion (BRVO), macular edema, retinal hemorrhage, and retina-choroiditis.

[0032] An ophthalmological apparatus according to an embodiment includes an ophthalmological information processing apparatus according to an embodiment and realizes the functions of the ophthalmological information processing apparatus according to an embodiment. An ophthalmological information processing method according to an embodiment includes one or more steps for realizing processing executed by a processor (computer) in the ophthalmological information processing apparatus according to an embodiment. A program according to an embodiment causes a processor to execute each step of the ophthalmological information processing method according to an embodiment. That is, the program according to an embodiment is a computer program including instructions that, when executed by a computer, cause the computer to execute the ophthalmological information processing method according to an embodiment. A recording medium (storage medium) according to an embodiment is any non-transitory recording medium readable by a computer on which a program according to an embodiment is recorded (stored). The recording medium may be an electronic medium that utilizes magnetism, light, magneto-optical technology, semiconductor technology, or the like. Typical recording media include magnetic tape, magnetic disks, optical disks, magneto-optical disks, flash memory, solid-state drives, and the like. Examples of magnetic disks include magnetic storage media such as hard disks, floppy disks, and ZIPs. Examples of magneto-optical disks include CD-ROMs, DVD-RAMs, DVD-ROMs, and MOs. It is also possible to transmit and receive this program via a network such as the Internet or a LAN.

[0033] In this specification, the term "processor" refers to a circuit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), or a programmable logic device (e.g., an SPLD (Simple Programmable Logic Device), a CPLD (Complex Programmable Logic Device), or an FPGA (Field Programmable Gate Array)). The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or a storage device.

[0034] Hereinafter, a case will be described in which an ophthalmic apparatus according to an embodiment irradiates a fundus with first and second lights having different center wavelengths as illumination light. That is, the ophthalmic apparatus acquires image data of two fundus images by receiving return light from the fundus, and generates a calculated image based on the image data of the two acquired fundus images. However, the following embodiment can also be applied to a case in which three or more lights having different center wavelengths are irradiated as illumination light to acquire image data of three or more fundus images, and a calculated image is generated based on the image data of the acquired three or more fundus images.

[0035] Furthermore, the ophthalmologic apparatus according to the embodiment is a fundus imaging apparatus having an optical system for imaging the fundus at a wide angle by including an objective optical system having two or more curved mirrors, illuminating the fundus of the subject's eye by a slit scan method, and receiving return light of the illumination light from the fundus. That is, the ophthalmologic apparatus according to the following embodiment is configured to scan the fundus of the subject's eye with slit-shaped illumination light via two or more curved mirrors, and receive return light from the fundus via two or more curved mirrors. By using the above optical system to simultaneously or sequentially irradiate the fundus of the subject's eye with a first slit-shaped light and a second slit-shaped light, and acquiring a first fundus image and a second fundus image, it is possible to easily acquire a wide-angle calculated image representing the structure of the fundus at a desired depth range.

[0036] However, the following embodiment can also be applied to a case where the objective optical system is configured to include a dioptric system equipped with an objective lens.

[0037] Furthermore, the ophthalmologic apparatus according to the embodiment may be a fundus camera or a scanning laser ophthalmoscope (SLO). The fundus camera is configured to irradiate an imaging area of ​​the fundus with illumination light and acquire a fundus image by receiving light returned from the fundus. The SLO is configured to scan a scan range of the fundus with laser light and acquire a fundus image formed based on the light returned from the fundus.

[0038] The embodiments are not limited to ophthalmic devices that photograph the fundus (fundus photographing devices), but can be applied to ophthalmic devices that observe the fundus (fundus observation devices). The following embodiments can also be applied to ophthalmic devices that photograph or observe a site other than the fundus of the subject's eye. Furthermore, the following embodiments can also be applied to ophthalmic devices that measure the fundus of the subject's eye or a site other than the fundus.

[0039] Furthermore, in this specification, the focal point may not only refer to a fixed point uniquely determined by the shape of a curved surface, but may also refer to a position where the concentration of light rays (light beams) reflected by a reflecting surface is higher than at other positions. Furthermore, the position of the pupil and the position of the iris of the subject's eye may be described as being substantially the same position. In this specification, a position optically conjugate with the pupil (iris) of the subject's eye or its vicinity is referred to as a pupil (iris) conjugate position. In other words, the pupil (iris) conjugate position is a position that is approximately optically conjugate with the pupil (iris) of the subject's eye. Furthermore, a position optically conjugate with the fundus of the subject's eye or its vicinity is referred to as a fundus conjugate position. In other words, the fundus conjugate position is a position that is approximately optically conjugate with the fundus of the subject's eye.

[0040] Furthermore, in this specification, "image data" and "image" based on "image data" may be described as being the same thing.

[0041] In the following embodiment, a case where a calculated image depicting the choroidal vascular region is acquired will be mainly described, but the embodiment can also be applied to a case where tissue other than the choroidal vascular region is depicted.

[0042] <Optical System> Figures 1 to 3 show examples of the configuration of the optical system of an ophthalmic apparatus according to an embodiment. Figure 1 is a schematic diagram showing an overview of the entire optical system of an ophthalmic apparatus according to an embodiment. Figure 1 shows a fundus conjugate position P and a pupil conjugate position Q. Figure 2 shows an example of the configuration of the light source unit 30 in Figure 1. Figure 3 shows an example of the configuration of the imaging device 70 in Figure 1.

[0043] The ophthalmic apparatus 1 includes an objective optical system 10, an illumination optical system 20 as an irradiation optical system, an imaging optical system 50 as a light-receiving optical system, and an optical path separating member 60. The optical path separating member 60 separates the optical path of the return light of the illumination light from the optical path of the illumination light. The ophthalmic apparatus 1 is configured to guide slit-shaped illumination light generated by the illumination optical system 20 to the fundus Ef of the subject's eye E via the objective optical system 10, and to guide the return light of the illumination light from the fundus Ef to the imaging optical system 50 via the objective optical system 10.

[0044] (Objective optical system 10) The objective optical system 10 is an optical system arranged opposite the subject's eye. The objective optical system 10 includes two or more curved mirrors and is configured to guide illumination light from the illumination optical system 20 to the fundus Ef and to guide return light of the illumination light from the fundus Ef to the imaging optical system 50.

[0045] Examples of curved mirrors include ellipsoidal mirrors, parabolic mirrors, hyperbolic mirrors, free-form mirrors, and mirrors whose reflective surfaces are expressed by high-order polynomials. The reflective surface of a curved mirror may be a concave reflective surface or a convex reflective surface. In this case, examples of curved mirrors include ellipsoidal concave mirrors, ellipsoidal convex mirrors, parabolic concave mirrors, parabolic convex mirrors, hyperbolic concave mirrors, hyperbolic convex mirrors, free-form mirrors with concave reflective surfaces, free-form surfaces with convex reflective surfaces, concave mirrors whose reflective surfaces are expressed by high-order polynomials, and convex mirrors whose reflective surfaces are expressed by high-order polynomials.

[0046] In this embodiment, the ophthalmic apparatus 1 is mainly equipped with two elliptical concave mirrors as the two curved mirrors. However, the following embodiment can be applied to an ophthalmic apparatus equipped with three or more curved mirrors.

[0047] 1, the objective optical system 10 includes a first elliptical concave mirror 11 and a second elliptical concave mirror 12. Each of the first elliptical concave mirror 11 and the second elliptical concave mirror 12 has a reflecting surface that is a concave ellipsoid.

[0048] The first elliptical concave mirror 11 has two optically conjugate focal points (a first focal point F1 and a second focal point F2). The first focal point F1 is a secondary pupil conjugate point of the subject's eye E (pupil), and the second focal point F2 is a primary pupil conjugate point of the subject's eye E (pupil).

[0049] The second elliptical concave mirror 12 has two optically conjugate focal points (a first focal point F3 and a second focal point F4). The first focal point F3 is a primary pupil conjugate point of the subject's eye E (pupil), and the second focal point F4 is a measurement position where the subject's eye E (pupil) can be positioned.

[0050] The first elliptical concave mirror 11 can be positioned so that the second focal point F2 coincides with or near the first focal point F3 of the second elliptical concave mirror 12. In some embodiments, the first elliptical concave mirror 11 is positioned so that the second focal point F2 coincides with or near a position that is optically conjugate with the first focal point F3 of the second elliptical concave mirror 12 (the conjugate position of the first focal point F3). In other words, the first focal point F1 and the second focal point F2 of the first elliptical concave mirror 11 and the first focal point F3 and the second focal point F4 of the second elliptical concave mirror 12 are each positioned at the pupil conjugate position Q.

[0051] This allows slit-shaped illumination light to be focused at the first focus F1 of the first elliptical concave mirror 11, so that illumination light can be incident at a wide angle onto the fundus Ef through the pupil of the test eye E, which is positioned at the second focus F4 of the second elliptical concave mirror 12.

[0052] (Illumination Optical System 20) The illumination optical system 20 includes a light source unit 30, an iris diaphragm 21, a slit 22, a relay lens 23, an optical scanner 40, and a relay lens 41. Each of the relay lenses 23 and 41 includes one or more lenses.

[0053] The light source unit 30 is configured to simultaneously or sequentially emit a first light in a first wavelength range having a first wavelength λ1 as a center wavelength and a second light in a second wavelength range having a second wavelength λ2 as a center wavelength. The penetration depth of the first light in the fundus Ef differs from the penetration depth of the second light in the fundus Ef.

[0054] In this embodiment, the first wavelength λ1 is a wavelength within the wavelength range of near-infrared light, and the second wavelength λ2 is a wavelength within the wavelength range of red light. Therefore, the depth position (penetration depth) that can be reached in the fundus Ef by the first light having the first wavelength λ1 as its central wavelength is deeper than the depth position that can be reached in the fundus Ef by the second light having the second wavelength λ2 as its central wavelength.

[0055] In some embodiments, the first wavelength λ1 is a wavelength within a wavelength range of 700 nm to 1000 nm (or 770 nm to 1000 nm), and the second wavelength λ2 is a wavelength within a wavelength range of 500 nm to 700 nm (or 640 nm to 770 nm).

[0056] In this embodiment, it is desirable to select the first wavelength λ1 and the second wavelength λ2 so that a difference image in which contrast is enhanced by the difference between imaging using light with different center wavelengths can be obtained. In this case, for example, a wavelength in the near-infrared range that can reduce glare for the subject and a wavelength in the red range can be used as the first wavelength λ1 and the second wavelength λ2. However, the first wavelength λ1 and the second wavelength λ2 do not have to be in the wavelength range of near-infrared light and the wavelength range of red light, respectively.

[0057] For example, in order to enhance the contrast of the choroidal vascular region, a wavelength having a depth of penetration near the sclera, which is the layer below the choroid, can be adopted as the first wavelength λ1, and a wavelength having a depth of penetration near the retinal pigment epithelium, which is the layer above the choroid, can be adopted as the second wavelength λ2.

[0058] As shown in FIG. 2, the light source unit 30 includes a light source 31, a projection lens 32, and wavelength selection filters 33A and 33B.

[0059] The light source 31 emits light in a wavelength range that includes a first wavelength λ1 and a second wavelength λ2. The light source 31 includes, for example, a light-emitting diode (LED), a laser diode (LD), a supercontinuum (SC) light source, a halogen lamp, or a xenon lamp. In some embodiments, the light source 31 includes a white light source or a light source capable of outputting light of each color component of RGB.

[0060] The wavelength-selective filter 33A transmits light of a first wavelength λ1 among the wavelength components of light emitted from the light source 31 and transmitted through the projection lens 32. The wavelength-selective filter 33B transmits light of a second wavelength λ2 among the wavelength components of light emitted from the light source 31 and transmitted through the projection lens 32. The wavelength-selective filters 33A and 33B are configured to be selectively positioned in the optical path of the light emitted from the light source 31. For example, the light source unit 30 includes a movement mechanism that moves the wavelength-selective filters 33A and 33B in a direction intersecting the optical path of the light emitted from the light source 31, and is configured to selectively position the wavelength-selective filters 33A and 33B in the optical path by driving the movement mechanism. In FIG. 2 , the wavelength-selective filters 33A and 33B are configured to be selectively positioned in the optical path of light transmitted through the projection lens 32. However, the wavelength-selective filters 33A and 33B may be configured to be selectively positioned between the light source 31 and the projection lens 32.

[0061] In some embodiments, the light source unit 30 includes a light source having a configuration capable of changing the center wavelength in response to an instruction from a control unit (described later), instead of the configuration shown in FIG. 2 . An example of such a light source is a wavelength swept light source. In this case, the light source unit 30 is capable of switching between emitting a first light having a first wavelength λ1 as a center wavelength and a second light having a second wavelength λ2 as a center wavelength in response to an instruction from the control unit (described later).

[0062] In some embodiments, the light source unit 30 includes a light source 31, a projection lens 32, and a single wavelength selection filter. In this case, the light source unit 30 can switch between emitting first light having a first wavelength λ1 as a center wavelength and second light having a second wavelength λ2 as a center wavelength by combining wavelength switching control of the light emitted from the light source 31 and insertion / removal control of the single wavelength selection filter.

[0063] As described above, the light source unit 30 includes a light source, a projection lens, and one or more wavelength selection filters.

[0064] The iris diaphragm 21 has one or more apertures formed at positions decentered from the optical axis of the illumination optical system 20. The iris diaphragm 21 is configured so that the aperture can be positioned at the pupil conjugate position Q. The iris diaphragm 21 functions as an illumination diaphragm. In other words, the aperture formed in the iris diaphragm 21 defines the incident position (incident shape) of the illumination light on the iris of the subject's eye E.

[0065] In some embodiments, the relative position between the light source unit 30 (light source 31) and the opening formed in the iris diaphragm 21 is configured to be changeable. This makes it possible to change the light amount distribution of light passing through the opening formed in the iris diaphragm 21. In some embodiments, the relative position and / or relative orientation of the light source 31 with respect to the opening formed in the iris diaphragm 21 is configured to be changeable.

[0066] The slit 22 has one or more openings formed therein. In this embodiment, the slit 22 has a single opening formed therein. In some embodiments, the opening formed in the slit 22 is formed so that its longitudinal direction coincides with the long axis direction of the first elliptical concave mirror 11 (the direction of the straight line connecting the first focal point F1 and the second focal point F2). The slit 22 (specifically, the opening) can be positioned at a fundus conjugate position P. The opening formed in the slit 22 defines the shape of the illumination area (irradiation pattern shape) on the fundus Ef.

[0067] The slit 22 can be moved in the optical axis direction of the illumination optical system 20 by a moving mechanism (specifically, a moving mechanism 22D described later) not shown in the figure, thereby making it possible to move the position of the slit 22 according to the state of the subject's eye E (specifically, the diopter (refractive power) or the shape of the fundus Ef (fundus curvature)).

[0068] For example, first control information that associates in advance the positions of the slit 22 on the optical axis of the illumination optical system 20 with a plurality of diopters is stored in a storage unit described later. A control unit described later refers to the first control information to identify the position of the slit 22 that corresponds to the diopter, and controls the moving mechanism 22D so that the slit 22 is positioned at the identified position.

[0069] Here, the light quantity distribution of the light passing through the opening formed in the slit 22 changes as the slit 22 moves. At this time, a control unit (described later) can change at least one of the relative position and the relative orientation of the light source 31 with respect to the slit 22 by controlling a movement mechanism (not shown) that moves the light source unit 30 (light source 31).

[0070] In some embodiments, the slit 22 is configured to be able to change at least one of the position and the shape of the opening without being moved in the optical axis direction, depending on the state of the subject's eye E. Such a function of the slit 22 is realized by, for example, a liquid crystal shutter.

[0071] The optical scanner 40 deflects slit-shaped illumination light generated by irradiating the slit 22 with light from the light source unit 30. The optical scanner 40 (specifically, the deflection surface) can be positioned at the pupil conjugate position Q. The optical scanner 40 is a uniaxial optical scanner that changes the orientation of the deflection surface around a predetermined deflection reference angle direction. The optical scanner 40 one-dimensionally deflects the slit-shaped illumination light. The optical scanner 40 deflects the illumination light in a direction intersecting (specifically, perpendicular to) the longitudinal direction of a slit image (an image of the opening formed in the slit 22) formed by the slit-shaped illumination light projected onto the fundus Ef of the subject's eye E. This causes the slit image to move in a direction intersecting the longitudinal direction of the slit image (the scanning direction).

[0072] The optical scanner 40 includes, for example, a galvanometer scanner, a microelectromechanical system (MEMS) scanner, a polygon mirror, or a resonant scanner. For example, the optical scanner 40 includes a galvanometer scanner that deflects the illumination light within a predetermined deflection angle range based on a predetermined deflection reference angle direction.

[0073] In some embodiments, the optical scanner 40 is a biaxial optical scanner that two-dimensionally deflects slit-shaped illumination light. For example, the optical scanner 40 includes a first scanner and a second scanner. The first scanner deflects the illumination light so as to move the irradiation area on the fundus Ef of the subject's eye E in a horizontal direction perpendicular to the optical axis of the illumination optical system 20. The second scanner deflects the illumination light deflected by the first scanner so as to move the irradiation area on the fundus Ef in a vertical direction perpendicular to the optical axis of the illumination optical system 20.

[0074] In some embodiments, the illumination optical system 20 includes a projector equipped with a light source, and the projector outputs slit-shaped illumination light. In this case, wavelength-selective filters 33A and 33B shown in FIG. 2 are selectively disposed in the optical path of the slit-shaped illumination light output from the projector. Examples of projectors include LCD (Liquid Crystal Display) projectors using a transmissive liquid crystal panel, LCOS (Liquid Crystal On Silicon) projectors using a reflective liquid crystal panel, and DLP (Digital Light Processing) (registered trademark) projectors using a DMD (Digital Mirror Device).

[0075] In the illumination optical system 20 configured as described above, illumination light having the first wavelength λ1 or the second wavelength λ2 as its center wavelength emitted from the light source unit 30 passes through an opening formed in the iris diaphragm 21 and is irradiated onto the slit 22. The illumination light that has passed through the opening formed in the slit 22 passes through the relay lens 23, is deflected by the deflection surface of the optical scanner 40, passes through the relay lens 41, and is guided to the optical path separating member 60.

[0076] (Optical Path Separating Member 60) The optical path separating member 60 optically separates the optical path of the imaging optical system 50 from the optical path of the illumination optical system 20. In some embodiments, the optical path separating member 60 optically coaxially couples the optical path of the illumination optical system 20 and the optical path of the imaging optical system 50. An optical coupling surface (optical separation surface) of the optical path separating member 60 between the optical path of the illumination optical system 20 and the optical path of the imaging optical system 50 can be located at the pupil conjugate position Q.

[0077] In some embodiments, the optical path separating member 60 includes a hole mirror in which an aperture is formed. The hole mirror functions as a photographic diaphragm. In this case, the aperture formed in the hole mirror can be positioned at the pupil conjugate position Q.

[0078] 1 , a relay lens 61 is disposed between the first elliptical concave mirror 11 and the optical path separating member 60. The relay lens 61 includes one or more lenses. In some embodiments, the relay lens 61 is omitted, and the optical path separating member 60 is disposed at or near the first focal point F1 of the first elliptical concave mirror 11.

[0079] 1, the slit-shaped illumination light deflected by the optical scanner 40 and passing through the relay lens 41 is reflected by a mirror formed around the opening of the hole mirror, passes through the relay lens 61, and is guided to the reflecting surface of the first elliptical concave mirror 11. Furthermore, the return light of the illumination light reflected from the reflecting surface of the first elliptical concave mirror 11 passes through the relay lens 61, passes through the opening formed in the hole mirror, and is guided to the imaging device 70 of the photographing optical system 50.

[0080] In some embodiments, the optical path separating member 60 includes a photographing diaphragm in which an aperture is formed, and a reflecting member. In this case, the aperture formed in the photographing diaphragm can be positioned at the pupil conjugate position Q. The slit-shaped illumination light deflected by the optical scanner 40 and transmitted through the relay lens 41 is reflected by the reflecting member, passes through the relay lens 61, and is guided to the reflecting surface of the first elliptical concave mirror 11. Furthermore, the return light of the illumination light reflected from the fundus Ef by the reflecting surface of the first elliptical concave mirror 11 passes through the relay lens 61, passes through the aperture formed in the photographing diaphragm, and is guided to the imaging device 70 of the photographing optical system 50.

[0081] (Photographing Optical System 50) The photographing optical system 50 includes a focusing lens 51, a relay lens 52, and an imaging device 70. Each of the focusing lens 51 and the relay lens 52 includes one or more lenses. In some embodiments, the relay lens 52 functions as an imaging lens that forms an image of the return light from the subject's eye E on the light receiving surface (imaging surface, detection surface) of the imaging device 70.

[0082] The focusing lens 51 can be moved in the optical axis direction of the photographing optical system 50 by a moving mechanism (specifically, a moving mechanism 51D described later), which is not shown. This allows the light receiving surface of the imaging device 70 for receiving the return light of the illumination light to be positioned at the fundus conjugate position P.

[0083] In some embodiments, the focusing lens 51 is omitted from the photographing optical system 50, and the relay lens 52 and the image capturing device 70 are configured to be movable integrally in the optical axis direction. Even in this case, by moving the relay lens 52 and the image capturing device 70 in the optical axis direction, the light receiving surface of the image capturing device 70 for receiving the return light of the illumination light can be positioned at the fundus conjugate position P.

[0084] The imaging device 70 includes one or more image sensors having wavelength sensitivity characteristics capable of detecting returned light of illumination light irradiated onto the fundus Ef by the illumination optical system 20. It is desirable that the wavelength range including the peak wavelength of the wavelength sensitivity characteristics of the one or more image sensors includes the central wavelength of the returned light. Therefore, when the illumination optical system 20 irradiates the fundus Ef with the first light and the second light, the imaging device 70 includes one or more image sensors whose wavelength range including the peak wavelength of the wavelength sensitivity characteristics includes the central wavelength of the returned light of the first light and the central wavelength of the returned light of the second light.

[0085] 3, the imaging device 70 includes a first image sensor 71A, a first imaging lens 72A, a second image sensor 71B, a second imaging lens 72B, and a beam splitter 73. The first image sensor 71A is a two-dimensional image sensor. The second image sensor 71B is also a two-dimensional image sensor.

[0086] The beam splitter 73 reflects light containing the wavelength component of the first returning light and transmits light containing the wavelength component of the second returning light among the returning light incident on the imaging device 70. The beam splitter 73 may be a dichroic mirror or a half mirror.

[0087] The first imaging lens 72A forms an image of the returned light reflected by the beam splitter 73 on the light-receiving surface of the first image sensor 71A. The first image sensor 71A has wavelength sensitivity characteristics that enable it to detect the returned light of the first light. In some embodiments, the first image sensor 71A and the first imaging lens 72A are configured to be movable integrally or individually in the optical axis direction. This makes it possible to position the light-receiving surface of the first image sensor 71A, on which the returned light forms an image, at a fundus conjugate position P.

[0088] The second imaging lens 72B forms an image of the returned light transmitted through the beam splitter 73 on the light-receiving surface of the second image sensor 71B. The second image sensor 71B has wavelength sensitivity characteristics that enable it to detect the returned second light. In some embodiments, the second image sensor 71B and the second imaging lens 72B are configured to be movable integrally or individually in the optical axis direction. This makes it possible to position the light-receiving surface of the second image sensor 71B, on which the returned light forms an image, at a fundus conjugate position P.

[0089] Each of the first image sensor 71A and the second image sensor 71B functions as a two-dimensional image sensor as a pixelated light receiver. Each of the first image sensor 71A and the second image sensor 71B can set a virtually movable light-receiving area (light-receiving area) at a fundus conjugate position P.

[0090] For example, the light reception results by each of the first image sensor 71A and the second image sensor 71B are captured and read out using a rolling shutter system. In some embodiments, the light reception results by each of the first image sensor 71A and the second image sensor 71B are captured and read out using a global shutter system in which the light reception area is changeable or movable. In some embodiments, a control unit, which will be described later, controls the reading of the light reception results by controlling each of the first image sensor 71A and the second image sensor 71B. In some embodiments, each of the first image sensor 71A and the second image sensor 71B can automatically output the light reception results for a predetermined number of lines together with information indicating the light reception position.

[0091] Each of the first image sensor 71A and the second image sensor 71B includes, for example, a complementary metal oxide semiconductor (CMOS) image sensor. In this case, each of the first image sensor 71A and the second image sensor 71B includes a plurality of pixels (light receiving elements) arranged in the row direction, which are then arranged in the column direction. Specifically, each of the first image sensor 71A and the second image sensor 71B includes a plurality of pixels arranged two-dimensionally, a plurality of vertical signal lines, and a plurality of horizontal signal lines.

[0092] In some embodiments, at least one of the first image sensor 71A and the second image sensor 71B includes, for example, a CCD (Charge Coupled Device) image sensor.

[0093] By capturing (reading) the results of receiving the returned light from the first image sensor 71A and the second image sensor 71B using a rolling shutter method, an image in a light-receiving area corresponding to a desired virtual opening shape extending in the row direction is obtained. Such control is disclosed, for example, in U.S. Patent No. 7,831,106 or U.S. Patent No. 8,237,835.

[0094] That is, the photographing optical system 50 is configured to capture the results of receiving the return light of the first light in a light-receiving area corresponding to the irradiation range of the first light on the fundus, and to capture the results of receiving the return light of the second light in a light-receiving area corresponding to the irradiation range of the second light on the fundus.

[0095] In some embodiments, at least one of the first elliptical concave mirror 11 and the second elliptical concave mirror 12 is a convex mirror (e.g., an elliptical convex mirror) whose reflective surface is formed in a convex shape. In some embodiments, at least one of the first elliptical concave mirror 11 and the second elliptical concave mirror 12 is a curved mirror whose reflective surface is a free-form surface.

[0096] The ophthalmologic apparatus 1 may also be provided with any element or unit, such as a member for supporting the face of the subject (a chin rest, a forehead rest, etc.).

[0097] <Processing system> Fig. 4 shows an example of the configuration of the processing system of the ophthalmic apparatus 1 according to the embodiment. Fig. 4 is a block diagram of an example of the configuration of the processing system of the ophthalmic apparatus 1 according to the embodiment. In Fig. 4, the same parts as in Fig. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0098] The processing system (control system) of the ophthalmic apparatus 1 is mainly configured with a control unit 100. The control unit 100 controls each unit of the ophthalmic apparatus 1.

[0099] The control unit 100 includes a main control unit 110 and a storage unit 120. The functions of the main control unit 110 are realized by, for example, one or more processors. The storage unit 120 stores in advance computer programs for controlling the ophthalmologic apparatus 1. These computer programs include a program for controlling the illumination optical system, a program for controlling the imaging optical system, a program for controlling the optical scanner, a program for image formation, a program for data processing, and a program for a user interface. The main control unit 110 operates in accordance with these computer programs, causing the control unit 100 to execute control processing.

[0100] (Main controller 110) The main controller 110 includes an illumination controller 111 and a light-receiving controller 112, and controls the illumination optical system 20 and the photographing optical system 50 to illuminate the fundus Ef with slit-shaped illumination light and capture the light-receiving results of the return light of the illumination light using a rolling shutter method. Furthermore, the main controller 110 controls the image forming unit 200, the data processor 210, and the user interface (UI) unit 80.

[0101] The illumination control unit 111 generates the first light or the second light as slit-shaped illumination light and irradiates the fundus Ef with the generated slit-shaped illumination light. At this time, the illumination control unit 111 deflects the slit-shaped illumination light using the optical scanner 40, thereby sequentially moving the illumination area of ​​the illumination light within a predetermined illumination range on the fundus Ef.

[0102] The light receiving control unit 112 moves through the light receiving areas of the first image sensor 71A and the second image sensor 71B in synchronization with the irradiation timing by the irradiation control unit 111, and sequentially captures the light receiving results in the light receiving areas corresponding to the above-mentioned irradiation areas.

[0103] The control of the illumination optical system 20 includes control of the light source unit 30, control of the moving mechanism 22D, control of the optical scanner 40, and the like.

[0104] Control of the light source unit 30 includes control of the light source 31 and control of the wavelength selection filters 33A and 33B. Control of the light source 31 includes turning on and off the light source 31 and adjusting the light intensity. Control of the wavelength selection filters 33A and 33B includes control of selectively inserting and removing the wavelength selection filters 33A and 33B into and from the optical path of the light emitted by the light source 31.

[0105] The moving mechanism 22D moves the slit 22 in the optical axis direction of the illumination optical system 20. The main control unit 110 outputs a control signal to the moving mechanism 22D to move the slit 22 by an amount and in a direction corresponding to the control signal.

[0106] For example, the ophthalmologic apparatus 1 is provided with an actuator that generates a driving force for driving the moving mechanism 22D and a transmission mechanism that transmits the driving force. The actuator is, for example, a pulse motor. The transmission mechanism is, for example, a combination of gears or a rack and pinion. The moving mechanism 22D receives, from the transmission mechanism, the driving force generated by the actuator under the control of the main controller 110, and moves the slit 22 in the optical axis direction.

[0107] Control of the optical scanner 40 includes control of the angle of the deflection surface that deflects the illumination light. By controlling the angle of the deflection surface, it is possible to control the deflection direction (scan direction) of the illumination light. By controlling the angle range of the deflection surface, it is possible to control the scan range (scan start position and scan end position). By controlling the speed at which the angle of the deflection surface is changed, it is possible to control the scan speed.

[0108] The control of the photographing optical system 50 includes control of the image pickup device 70 and control of the moving mechanism 51D.

[0109] Control of the imaging device 70 includes control of the first image sensor 71A and the second image sensor 71B. Control of the first image sensor 71A and the second image sensor 71B includes control for setting the light-receiving area on the light-receiving surface and control for reading out the light-receiving results using a rolling shutter method (e.g., setting the light-receiving size corresponding to the size of the illumination pattern). Control of the first image sensor 71A and the second image sensor 71B also includes control for resetting accumulated charge in pixels, exposure control for accumulating charge in pixels, charge transfer control for transferring accumulated charge in pixels, and output control for outputting a signal corresponding to the amount of transferred charge.

[0110] The moving mechanism 51D serves as a focusing mechanism and moves the focusing lens 51 in the optical axis direction of the photographing optical system 50. The main control unit 110 outputs a control signal to the moving mechanism 51D to move the focusing lens 51 by an amount and in a direction corresponding to the control signal. For example, the ophthalmologic apparatus 1 is provided with an actuator that generates a driving force for driving the moving mechanism 51D and a transmission mechanism that transmits this driving force. The actuator is, for example, constituted by a pulse motor. The transmission mechanism is, for example, constituted by a combination of gears or a rack and pinion. The moving mechanism 51D receives the driving force generated by the actuator under the control of the main control unit 110 and moves the focusing lens 51 in the optical axis direction of the photographing optical system 50.

[0111] The control of the image forming unit 200 includes image formation control for forming a first fundus image and a second fundus image of the fundus oculi Ef from the light reception results obtained by the first image sensor 71A or the second image sensor 71B.

[0112] Control of the data processing unit 210 includes control of image processing, registration processing, calculated image generation processing, analysis processing, etc. Image processing is performed on at least one of the first fundus image and the second fundus image. Registration processing is a process of aligning the first fundus image and the second fundus image (between two or more fundus images). Calculated image generation processing is a process of generating a calculated image such as a difference image. Analysis processing is performed on the first fundus image, the second fundus image, and the calculated image.

[0113] The control over the UI unit 80 includes control over the display device, control over the operation device (input device), and the like.

[0114] The main control unit 110 that executes the above-described control sequentially controls the acquisition of the first fundus image and the second fundus image by the illumination control unit 111 and the light reception control unit 112 .

[0115] Fig. 5 is an explanatory diagram of the timing of acquiring the first fundus image by the illumination control unit 111 and the light receiving control unit 112 according to the embodiment. Fig. 5 schematically shows an illumination area IP of slit-shaped illumination light irradiated onto the fundus Ef at time t1, and a virtual aperture range OP on the light receiving surface SR of the first image sensor 71A.

[0116] For example, the illumination control unit 111 controls the light source unit 30 to generate slit-shaped illumination light from the first light having a first wavelength λ1 as the center wavelength, and deflects the generated slit-shaped illumination light using the optical scanner 40. As a result, the illumination area IP of the slit-shaped illumination light is sequentially moved in a direction (e.g., vertical direction) perpendicular to the slit direction (e.g., row direction, horizontal direction) on the fundus Ef (from time t1 to time t2).

[0117] On the light-receiving surface SR of the first image sensor 71A, a virtual aperture range OP is set by changing the pixels to be read line by line using the light-receiving control unit 112. The aperture range OP is preferably a light-receiving area IP' of the returned light of the illumination light on the light-receiving surface SR or a range wider than the light-receiving area IP'. The light-receiving control unit 112 controls the movement of the aperture range OP in synchronization with the control of the movement of the illumination light irradiation area IP (time t1 to time t2). This makes it possible to acquire high-quality images of the fundus Ef with strong contrast using a simple configuration without being affected by unnecessary scattered light.

[0118] The main controller 110 can also function as a display controller. In this case, the main controller 110 can display at least two of the first fundus image, the second fundus image, and the difference image (calculated image) in parallel on the screen of a display device provided in the UI unit 80. In some embodiments, the main controller 110 displays the first fundus image and the second fundus image in a superimposed manner on the screen of the display device provided in the UI unit 80. In some embodiments, the main controller 110 displays the first fundus image or the second fundus image and the difference image (calculated image) in a superimposed manner on the screen of the display device provided in the UI unit 80. In some embodiments, the main controller 110 displays the first fundus image or the second fundus image and the difference image (calculated image) in association with each other on the screen of the display device provided in the UI unit 80. In some embodiments, the main control unit 110 causes the screen of a display device provided in the UI unit 80 to display the difference between the first fundus image or the second fundus image and the difference image (calculated image) in a distinguishable manner.

[0119] (Storage Unit 120) The storage unit 120 stores various types of data. Examples of data stored in the storage unit 120 include light reception results obtained by the first image sensor 71A and the second image sensor 71B, image data of images formed by the image forming unit 200, processing results obtained by the data processing unit 210, image data of calculated images, and information about the subject's eye. The information about the subject's eye includes information about the subject, such as a patient ID and name, and information about the subject's eye, such as identification information for the left eye or right eye.

[0120] The storage unit 120 also stores various programs and data for operating the ophthalmologic apparatus 1 .

[0121] (Image forming unit 200) The image forming unit 200 forms a first fundus image, which is a light-receiving image corresponding to an arbitrary aperture range, based on the light-receiving result read out from the first image sensor 71A by the rolling shutter method under the control of the main control unit 110 (control unit 100). The image forming unit 200 is able to form the first fundus image by sequentially forming light-receiving images corresponding to a (virtual) aperture range and arranging the formed multiple light-receiving images in a direction corresponding to the scanning direction of the illumination light.

[0122] Similarly, the image forming unit 200 forms a second fundus image, which is a light-receiving image corresponding to an arbitrary aperture range, based on the light-receiving result read out from the second image sensor 71B by the rolling shutter method under the control of the main control unit 110 (control unit 100). The image forming unit 200 is able to form the second fundus image by sequentially forming light-receiving images corresponding to a (virtual) aperture range and arranging the formed multiple light-receiving images in a direction corresponding to the scanning direction of the illumination light.

[0123] Various images (image data) formed by the image forming unit 200 are stored in the storage unit 120, for example.

[0124] For example, the image forming unit 200 includes one or more processors, and performs processing in accordance with a program stored in a storage unit or the like, thereby realizing the above functions.

[0125] (Data Processing Unit 210) The data processing unit 210 performs various image processing, calculation image generation processing, and analysis processing on the light reception results acquired by the first image sensor 71 A and the second image sensor 71 B. The image processing includes noise removal processing on the light reception results and brightness correction processing to make it easier to identify specific parts depicted in the light reception image based on the light reception results.

[0126] The data processing unit 210 includes one or more processors, and performs processing according to a program stored in a storage unit or the like to realize the above functions. For example, the functions of the data processing unit 210 are realized by multiple processors. In this case, each processor is configured to realize the function of each unit in FIG. 6.

[0127] Fig. 6 is a block diagram showing an example of the configuration of the data processing unit 210 shown in Fig. 4. In Fig. 6, the same parts as those in Fig. 4 are given the same reference numerals, and the description thereof will be omitted where appropriate.

[0128] The data processing unit 210 includes a registration processing unit 211, a calculated image generating unit 212, and an analyzing unit 220. The analyzing unit 220 includes a complementing processing unit 221, a blood vessel state specifying unit 222, and a symmetry determining unit 223.

[0129] (Registration Processing Unit 211) The registration processing unit 211 performs registration processing on the first fundus image and the second fundus image formed by the image forming unit 200. The registration processing unit 211 aligns the first fundus image and the second fundus image by relatively shifting or rotating the first fundus image and the second fundus image. Prior to the registration processing, the data processing unit 210 may adjust the brightness of a predetermined portion of at least one of the first fundus image and the second fundus image.

[0130] In some embodiments, the registration processing unit 211 performs a process of identifying a specific area on each of the first fundus image and the second fundus image, and aligns the identified areas so that the positions and orientations of the specific areas in both images match.

[0131] In some embodiments, the registration processor 211 calculates a shift amount based on the correlation value between the first fundus image and the second fundus image, and aligns the first fundus image and the second fundus image relative to each other based on the calculated shift amount. In this case, the registration processor 211 calculates the correlation value between the first fundus image and the second fundus image using a known correlation function. The registration processor 211 changes the shift amount (horizontal, vertical, or rotational) of one of the first fundus image and the second fundus image and recalculates the correlation value. Based on a comparison between the original correlation value and the newly calculated correlation value, the registration processor 211 determines whether to update the shift amount and calculate a new correlation value. The registration processor 211 repeatedly calculates and compares the correlation value to determine the shift amount (including the shift direction) that maximizes the correlation value, and aligns the first fundus image and the second fundus image based on the calculated shift amount.

[0132] In some embodiments, the registration processing unit 211 calculates a shift amount between the first fundus image and the second fundus image by performing a phase-only correlation process on the first fundus image and the second fundus image, and aligns the first fundus image and the second fundus image by shifting at least one of the first fundus image and the second fundus image in the horizontal direction, the vertical direction, or the rotational direction based on the calculated shift amount.

[0133] For example, if the difference between the timing at which the first fundus image is acquired and the timing at which the second fundus image is acquired is negligibly small, the registration processing by the registration processing unit 211 can be omitted.

[0134] (Calculated image generating unit 212) The calculated image generating unit 212 generates a calculated image by performing image comparison processing on the first fundus image and the second fundus image that have been aligned by the registration processing unit 211. Specifically, the calculated image generating unit 212 obtains the pixel value of each pixel of the calculated image by performing a predetermined calculation processing (image comparison processing) on ​​pixel values ​​of corresponding pixels in the first fundus image and the second fundus image.

[0135] Examples of the predetermined arithmetic processing include difference processing, weighted difference processing, addition processing, weighted addition processing, ratio calculation processing, weighted ratio calculation processing, average processing, weighted average processing, logarithmic calculation processing, and predetermined pixel calculation processing.

[0136] Examples of predetermined pixel calculation processes include calculation processes according to a predetermined function using two pixel values ​​of corresponding pixels as variables, and calculation processes performed in a trained model obtained by prior machine learning. The trained model can be constructed by, for example, training the learning model using training data through known machine learning such as supervised learning. In this case, the training data may be multiple sets of image data, each set consisting of image data of a pair of fundus images acquired using first and second light as illumination light. Furthermore, the training data may be a fluorescent angiography image, an OCTA image (OCT image), an image obtained by extracting components in a predetermined wavelength range from a fundus image acquired by another fundus imaging device, or a fundus image (calculated image) whose contrast is adjusted by a user such as a doctor. For example, when one or more pieces of training data are sequentially input into the learning model, the trained model can be constructed by adjusting parameters within the model so that the output data for all of the input one or more pieces of training data approximately matches the training data.

[0137] In this embodiment, the calculated image generating unit 212 generates a difference image as a calculated image from the first fundus image and the second fundus image. Specifically, the calculated image generating unit 212 generates the difference image by performing differential processing on the pixel values ​​of the first fundus image and the pixel values ​​of the second fundus image for each pixel.

[0138] In some embodiments, the penetration depth in the fundus Ef of the first light used to acquire the first fundus image and the penetration depth in the fundus Ef of the second light used to acquire the second fundus image are different from each other.

[0139] Fig. 7 is an explanatory diagram of the penetration depth of the first light and the second light in the fundus Ef according to the embodiment. Fig. 7 schematically shows the penetration depth of the first light and the penetration depth of the second light in the cross-sectional structure of the fundus Ef. In Fig. 7, the internal limiting membrane LY1, the retinal pigment epithelium LY2, the choroid LY3, and the sclera LY4 are schematically shown as the cross-sectional structure of the fundus Ef.

[0140] The first light having the first wavelength λ1 as its center wavelength is incident on the fundus Ef, for example, passes through the internal limiting membrane LY1, reaches the vicinity of the sclera LY4, and is reflected at each depth position. On the other hand, the second light having the second wavelength λ2 as its center wavelength is incident on the fundus Ef, for example, passes through the internal limiting membrane LY1, reaches the vicinity of the retinal pigment epithelium LY2, and is reflected at each depth position.

[0141] In this case, the first fundus image formed based on the return light of the first light is an image that depicts up to a depth position corresponding to the penetration depth of the first light, and the second fundus image formed based on the return light of the second light is an image that depicts up to a depth position corresponding to the penetration depth of the second light.

[0142] FIG. 8 is a diagram illustrating the operation of the calculated image generating unit 212 according to the embodiment.

[0143] 7, the penetration depth of the second light in the fundus oculi Ef is shallower than the penetration depth of the first light. Therefore, the calculated image generating unit 212 generates a difference image IMG3 by, for example, performing an image comparison process (difference process) in which, for each pixel, the pixel value of the second fundus oculi image IMG2 is subtracted from the pixel value of the first fundus oculi image IMG1.

[0144] This makes it possible to easily obtain a difference image IMG3 in which brightness values ​​corresponding to tissues and areas in the depth range from the depth position corresponding to the depth of the first light to the depth position corresponding to the depth of the second light are projected in the depth direction for each pixel.

[0145] For example, when the penetration depths of the first light and the second light are as shown in Fig. 7, the subtraction image IMG3 is an image that simulates an en-face image of the layer region of the choroid. Such a subtraction image IMG3 is a front image that represents the morphology of the choroidal blood vessels.

[0146] In some embodiments, the calculated image generating unit 212 generates a difference image by weighting each pixel and performing difference processing between the pixel values ​​of the first fundus image and the pixel values ​​of the second fundus image. In this case, it is possible to perform image comparison processing (difference processing) between the pixel values ​​of the first fundus image and the pixel values ​​of the second fundus image for each pixel using a weighting coefficient that is preset for each image region, tissue, part, or depth range.

[0147] In some embodiments, the calculated image generation unit 212 generates a difference image that depicts pixels in the first fundus image and the second fundus image in a manner that makes it possible to identify pixels whose corresponding pixel value (brightness value) difference is greater than or equal to a predetermined threshold.

[0148] (Analysis unit 220) The analysis unit 220 performs analysis processing on the calculated image. The analysis processing includes processing for identifying a predetermined part depicted in the calculated image, processing for complementing a defective part in the part depicted in the calculated image, and processing for analyzing the shape of the part, tissue, or blood vessel region depicted in the calculated image.

[0149] (Complement Processing Unit 221) The analysis unit 220 can identify defective parts (particularly breaks in blood vessel regions) in the computed image generated by the computed image generation unit 212. The complement processing unit 221 executes complement processing for the defective parts identified in the computed image.

[0150] In some embodiments, the complement processing unit 221 identifies a defect in a predetermined site, tissue, or vascular region depicted in the computed image by analyzing the computed image, and complements the identified defect. For example, the complement processing unit 221 identifies a vascular region, tracks the identified vascular region to identify a defect in the vascular region, and complements the defect by connecting end portions of the identified defect based on a known approximation function. For example, the complement processing unit 221 complements the defect by connecting end portions of the identified defect using a pixel region corresponding to the end portion in the first fundus image or the second fundus image.

[0151] In some embodiments, the complementation processing unit 221 outputs a calculated image in which the defect portion is complemented by inputting a difference image into a trained model obtained by performing machine learning in advance. For example, the complementation processing unit 221 can construct a trained model by performing known machine learning on a trained model that receives a calculated image as input and outputs a calculated image in which the defect portion is complemented.

[0152] For example, the completion processing unit 221 can construct a learned model by training a learning model using training data using known machine learning methods such as supervised machine learning, unsupervised machine learning, or semi-supervised learning.

[0153] In the case of supervised learning, the complementation processing unit 221 constructs a trained model by performing machine learning on the learning model using training data with correct answer labels as teacher data. The teacher data is correct answer data to which correct answer labels (or annotations) are attached in advance by a doctor or the like.

[0154] The learning model has, for example, the configuration of a convolutional neural network (CNN). The CNN includes a convolutional layer, a downsampling layer (pooling layer), a fully connected layer, and an output layer. The CNN may include multiple units in which units including convolutional layers and downsampling layers are connected in multiple stages. In each unit, for example, the output of the convolutional layer is connected to the input of the downsampling layer.

[0155] When input data is input to such a learning model, output data is obtained according to the configuration of the learning model that can be adjusted by parameters. Here, the parameters include at least one of a weighting coefficient, a kernel size of a convolutional layer or a deconvolutional layer, a kernel value, a stride value, a padding value, and a duration value. When one or more pieces of training data are sequentially input to the learning model, the complementation processing unit 221 adjusts the parameters so that the output data for all of the one or more pieces of training data input approximately matches the correct answer data. This constructs a trained model whose parameters are adjusted by supervised learning.

[0156] In the case of unsupervised learning, the complementation processing unit 221 constructs a trained model by performing machine learning on the learning model using one or more training data sets without a correct answer label. When one or more training data sets are sequentially input to the learning model, the complementation processing unit 221 adjusts parameters so as to characterize the input one or more training data sets. By adjusting the parameters so that the output data of the trained model complements defects, a trained model having a configuration in which parameters are adjusted by machine learning is constructed without creating teacher data.

[0157] The completion processing unit 221 may also construct a trained model by performing unsupervised learning on the training model using a generative adversarial network (GAN) or a deep convolutional generative adversarial network (DCGAN). The GAN or DCGAN includes a generator and a classifier. The generator generates fake data from random noise. The classifier determines whether true data matches the fake data. By repeatedly training the generator to generate fake data that approaches true data and the classifier to distinguish true data from fake data generated by the generator in an adversarial manner, the generator becomes able to generate fake data that is close to true data. The configuration of the trained generator corresponds to the configuration of the trained model according to the embodiment.

[0158] In the case of semi-supervised learning, the complementation processing unit 221 constructs a trained model by performing machine learning on the learning model using teacher data and training data without correct answer labels. For example, the complementation processing unit 221 constructs a trained model by adjusting parameters by the unsupervised learning of the trained model obtained by training the learning model by the supervised learning. Alternatively, for example, the complementation processing unit 221 constructs a new trained model by adjusting parameters by the supervised learning of the trained model obtained by training the learning model by the unsupervised learning.

[0159] The complementing processing unit 221 may construct the trained model by known machine learning such as reinforcement learning. Furthermore, the complementing processing unit 221 can update parameters by performing additional machine learning on the trained model, and reconstruct the configuration of a new trained model.

[0160] (Vascular Condition Identification Unit 222) The vascular condition identification unit 222 identifies the vascular condition depicted in the calculated image (difference image) or the calculated image in which defective portions are complemented by the complementation processing unit 221. Examples of the identified vascular condition include choroidal blood vessels (area), the course of choroidal blood vessels, the diameter (thickness) of choroidal blood vessels, the density of choroidal blood vessels, and the number (and / or density) of choroidal blood vessels connected to multiple (e.g., four) vortex veins at the fundus.

[0161] For example, the vascular condition specifying unit 222 specifies choroidal vessels (regions) depicted in the computed image (difference image) or the computed image in which defects are complemented by the complement processing unit 221, and specifies the diameters of the specified choroidal vessels. In some embodiments, the vascular condition specifying unit 222 specifies the diameters of each of a predetermined number of the specified choroidal vessels, or the maximum diameter of the specified choroidal vessels. The diameters of the choroidal vessels specified by the vascular condition specifying unit 222 include the number of pixels corresponding to the vessel diameter, size information obtained by multiplying the number of pixels corresponding to the vessel diameter by the pixel size, and the like.

[0162] In some embodiments, the vascular condition specifying unit 222 tracks the specified choroidal vessels (region) and specifies the running state (running pattern) of the choroidal vessels. The vascular condition specifying unit 222 can also specify the density of the choroidal vessels (region) per unit area by calculating the area of ​​the choroidal vessel region within a specified region. In this case, the vascular condition specifying unit 222 can specify the density of the choroidal vessels within a region specified by a doctor or the like using the UI unit 80 on a calculated image displayed on the screen of the display device of the UI unit 80.

[0163] In some embodiments, the vascular condition specifying unit 222 can specify four vortex veins in the fundus, specify choroidal vessels connected to the specified vortex veins, and specify the number of specified choroidal vessels. Furthermore, the vascular condition specifying unit 222 can specify the density of choroidal vessels connected to the vortex veins by calculating the area of ​​the choroidal vascular region connected to the vortex veins within a predetermined region. In this case, the vascular condition specifying unit 222 can specify the number of choroidal vessels and / or the density of choroidal vessels for each specified vortex vein.

[0164] (Symmetry Determination Unit 223) The symmetry determination unit 223 performs a determination process for the symmetry of the running state of the choroidal blood vessels (regions) depicted in the calculated image or the calculated image in which defects are complemented by the complement processing unit 221, and outputs the determination result of the running state. Examples of the determination result include information indicating whether the running state is symmetrical or not, information indicating the degree of symmetry of the running state, etc.

[0165] In some embodiments, the symmetry determination unit 223 outputs information indicating whether the course of the choroidal blood vessels is symmetrical with respect to a predetermined symmetry axis that divides the choroidal vascular region in which the choroidal blood vessels are distributed. An example of the symmetry axis is a line connecting the optic disc (center or center of gravity) and the macula (center or center of gravity). When the choroidal vascular region is divided into multiple regions by the symmetry axis, for example, the symmetry determination unit 223 can generate an image in which the choroidal vascular region in each region in the calculated image is depicted in a manner that makes it distinguishable from the choroidal vascular region in other regions.

[0166] In some embodiments, the symmetry determination unit 223 outputs information indicating the degree of symmetry of the course of the choroidal blood vessels with respect to the symmetry axis. An example of the information indicating the degree of symmetry is the proportion of the area of ​​the choroidal vascular region that is determined to be symmetrical to the total area of ​​the choroidal vascular region. In this case, the symmetry determination unit 223 can generate an image in which the choroidal vascular region that is determined to be symmetrical in the calculated image is clearly depicted.

[0167] In some embodiments, the symmetry determination unit 223 identifies an axis of symmetry by analyzing the course of the choroidal blood vessels, and performs a process of determining the symmetry of the course of the choroidal blood vessels with respect to the identified axis of symmetry. In this case, the symmetry determination unit 223 can output information indicating whether the course of the choroidal blood vessels is symmetric with respect to the identified axis of symmetry, information indicating the degree of symmetry of the course of the choroidal blood vessels, an image in which the axis of symmetry identified in the calculated image is depicted in a distinguishable manner, and the like.

[0168] In some embodiments, the symmetry determination unit 223 analyzes the running state of the choroidal blood vessels identified by the vascular state identification unit 222 and identifies an axis of symmetry so that the running state is symmetrical. The symmetry determination unit 223 can output information indicating whether the running state is symmetrical or not based on the position or orientation of the identified axis of symmetry.

[0169] In some embodiments, the symmetry determination unit 223 outputs information that assists a doctor or the like in determining the symmetry of the course of the choroidal blood vessels with respect to the symmetry axis. Examples of information that assists in determining the symmetry include the symmetry axis, an image in which the choroidal blood vessels are depicted in a distinguishable manner in the computed image, and an image in which the areas in which the choroidal blood vessel area is divided by the symmetry axis in the computed image are depicted in a distinguishable manner.

[0170] In some embodiments, the symmetry determination unit 223 performs a process of determining the symmetry of the course state of the choroidal blood vessels with respect to an axis of symmetry designated by a doctor or the like via the UI unit 80 (described later). In this case, the symmetry determination unit 223 can output information indicating whether the course state of the choroidal blood vessels is symmetrical with respect to the designated axis of symmetry, and information indicating the degree of symmetry of the course state.

[0171] In some embodiments, the symmetry determination unit 223 performs a process for determining the symmetry of the course state of the choroidal blood vessels based on the deviation of the course state of the choroidal blood vessels from a predetermined reference course pattern. In this case, the symmetry determination unit 223 can output information indicating whether the course state of the choroidal blood vessels is symmetrical, information indicating the degree of symmetry of the course state, etc. The predetermined reference course pattern may be standard data (normative data) of the course pattern of the choroidal blood vessels or a course pattern of the choroidal blood vessels of the same test eye previously acquired.

[0172] In some embodiments, the symmetry determination unit 223 performs the symmetry determination process using a trained model obtained by performing machine learning similar to that described above in advance. For example, the symmetry determination unit 223 can construct a trained model by performing known machine learning on a trained model that receives a calculated image as input and outputs information indicating whether the choroidal vessels are symmetrical and / or information indicating the degree of symmetry of the choroidal vessels.

[0173] For example, in the case of supervised learning, the symmetry determination unit 223 constructs a trained model by performing machine learning on the learning model using training data with correct answers labels as teacher data. The teacher data is correct answer data to which correct answers labels (or annotations) are attached in advance by a doctor or the like.

[0174] In the embodiment, a wide-angle fundus image in which one or more vortex veins are depicted can be acquired. Therefore, according to the embodiment, the symmetry of the course of the choroidal blood vessels connected to each vortex vein can be determined, thereby improving the accuracy of the symmetry determination compared to when the symmetry is determined only based on the choroidal blood vessels near the optic disc and the macula.

[0175] In some embodiments, the analysis unit 220 identifies choroidal blood vessels depicted in the calculated image or the calculated image in which defects have been complemented by the complement processing unit 221, and performs processing to determine the tortuosity of the course of the identified choroidal blood vessels. Examples of the determination result include information indicating whether the course of the choroidal blood vessels is tortuosity, information indicating the degree of tortuosity of the course of the choroidal blood vessels, information indicating the number of times the course of the choroidal blood vessels is tortuosity, etc.

[0176] In some embodiments, the symmetry determination unit 223 performs a process for determining the tortuosity of the choroidal vessel course based on the deviation of the choroidal vessel course from a predetermined reference course pattern. In this case, the symmetry determination unit 223 can output information indicating whether the choroidal vessel course is tortuosity, information indicating the degree of tortuosity of the choroidal vessel course, the number of times the choroidal vessel course is tortuosity, etc. The predetermined reference course pattern may be standard data (normative data) of the choroidal vessel course pattern or a choroidal vessel course pattern of the same test eye previously acquired.

[0177] In some embodiments, the symmetry determination unit 223 performs the tortuosity determination process using a trained model obtained by performing machine learning similar to that described above in advance. For example, the symmetry determination unit 223 can construct a trained model by performing known machine learning on a trained model that receives a calculated image as input and outputs information indicating whether the choroidal vessels are tortuosity, information indicating the degree of tortuosity of the choroidal vessels, and / or the number of times the choroidal vessels tortuosity.

[0178] For example, in the case of supervised learning, the symmetry determination unit 223 constructs a trained model by performing machine learning on the learning model using training data with correct answers labels as teacher data. The teacher data is correct answer data to which correct answers labels (or annotations) are attached in advance by a doctor or the like.

[0179] In addition, the analysis unit 220 can identify areas corresponding to vortex veins by analyzing the first fundus image, the second fundus image, or the calculated image, and generate new images in each image in which the identified areas are clearly depicted.

[0180] Furthermore, the analysis unit 220 can identify abnormalities (e.g., tears) in the choroidal blood vessels by analyzing the computed image, and estimate the possibility of exudative age-related macular degeneration based on the identified abnormalities.

[0181] In addition, the analysis unit 220 can identify an abnormal choroidal vascular network and polypoidal lesions at its tip by analyzing the computed image, and estimate the possibility of polypoidal choroidal vasculopathy based on the identified choroidal vascular network and polypoidal lesions.

[0182] The analysis unit 220 according to the embodiment can perform the above-described process of estimating the possibility of fundus disease using a trained model obtained by performing machine learning similar to that described above in advance.

[0183] (UI Unit 80) The UI unit 80 has a function for exchanging information between a user (examiner or subject) and the ophthalmologic apparatus 1. The UI unit 80 includes a display device and an operation device. The display device may include a display unit or other display devices. The display device displays various information. The display device includes, for example, a liquid crystal display, and displays the information under control of the main control unit 110. Information displayed on the display device includes information corresponding to the control results by the control unit 100, information (images) corresponding to the calculation results by the image forming unit 200 or the data processing unit 210, and the like. The operation device includes various hardware keys and / or software keys. The main control unit 110 can receive operation content for the operation device and output control signals corresponding to the operation content to each unit. At least a portion of the operation device and at least a portion of the display device can be configured integrally. A touch panel display is one example.

[0184] The ophthalmologic apparatus 1 according to the embodiment repeatedly acquires the above-described calculated image (difference image) and performs an averaging of the acquired multiple calculated images, thereby enabling the contrast of the calculated image to be increased. In this case, the ophthalmologic apparatus 1 is configured to repeatedly irradiate the first light and the second light onto the fundus oculi Ef and repeatedly acquire the first fundus image and the second fundus image.

[0185] Fig. 9A schematically shows an example of the timing of irradiation of the first light and the second light according to the embodiment. In Fig. 9A, the horizontal axis represents time, and the vertical axis represents the deflection angle of the illumination light by the optical scanner 40. In Fig. 9A, in order to move the irradiation area of ​​the slit-shaped illumination light to cover a predetermined illumination range of the fundus Ef, the orientation of the deflection surface of the optical scanner 40 is changed so that the deflection angle is in the range of "+d degrees" to "-d degrees," with a predetermined deflection reference angle direction being "0 degrees."

[0186] 9A , the fundus Ef is illuminated with a first light having a first wavelength λ1 as its center wavelength while being sequentially deflected from a deflection angle of "+d degrees" to "-d degrees," and a first fundus image is acquired by sequentially receiving the returning light from the fundus Ef. Furthermore, the fundus Ef is illuminated with a second light having a second wavelength λ2 as its center wavelength while being sequentially deflected from a deflection angle of "-d degrees" to "+d degrees," and a second fundus image is acquired by sequentially receiving the returning light from the fundus Ef. Similarly, the first light and the second light are then repeatedly irradiated onto the fundus Ef, thereby sequentially acquiring the first and second fundus images.

[0187] Therefore, the calculated image generating unit 212 can sequentially generate the above-mentioned calculated images (difference images) from a pair of the first fundus image and the second fundus image. The calculated image generating unit 212 can generate a high-contrast calculated image by performing averaging on each pixel of the sequentially generated multiple calculated images.

[0188] 9B schematically shows another example of the irradiation timing of the first light and the second light according to the embodiment. In FIG. 9B, as in FIG. 9A, the horizontal axis represents time, and the vertical axis represents the deflection angle of the illumination light by the optical scanner 40. In FIG. 9B, as in FIG. 9A, the orientation of the deflection surface of the optical scanner 40 is changed within the range of "+d degrees" to "-d degrees" with a predetermined deflection reference angle direction being "0 degrees."

[0189] In Figure 9B, each time the deflection angle is changed in predetermined steps between the deflection angle "+d degrees" and "-d degrees," the fundus Ef is illuminated by switching between the first light and the second light, and the return light from the fundus Ef is sequentially received. When illumination of a predetermined illumination range on the fundus Ef with the first light is completed, a first fundus image is formed using the sequentially acquired light reception results of the return light of the first light. Similarly, when illumination of a predetermined illumination range on the fundus Ef with the second light is completed, a second fundus image is formed using the sequentially acquired light reception results of the return light of the second light. Thereafter, in the same manner, the first light and the second light are repeatedly irradiated onto the fundus Ef, thereby sequentially acquiring first and second fundus images.

[0190] 9A , the calculated image generating unit 212 can sequentially generate the above-mentioned calculated images from a pair of the first fundus image and the second fundus image. The calculated image generating unit 212 can generate a single high-contrast calculated image by performing averaging on each pixel of the sequentially generated calculated images.

[0191] In some embodiments, a plurality of first fundus images are acquired by repeatedly illuminating a predetermined illumination range on the fundus oculi Ef with a first light, and a plurality of second fundus images are acquired by repeatedly illuminating the illumination range with a second light. The calculated image generation unit 212 generates a plurality of calculated images by generating a calculated image from any one of a first fundus image group consisting of a plurality of first fundus images and any one of a second fundus image group consisting of a plurality of second fundus images. The calculated image generation unit 212 is able to generate a single high-contrast calculated image by performing averaging on each pixel of the plurality of calculated images.

[0192] In some embodiments, the ophthalmic device is configured to acquire a plurality of computed images in time series. In this case, the ophthalmic device simultaneously or sequentially irradiates the fundus with the first light and the second light to acquire a first fundus image and a second fundus image, and after a predetermined time has elapsed, repeatedly irradiates the fundus with the first light and the second light again simultaneously or sequentially to acquire a first fundus image and a second fundus image. The ophthalmic device is able to acquire a plurality of computed images in time series by sequentially generating computed images from the sequentially acquired first fundus image and second fundus image.

[0193] The data processing unit 210 is an example of an "ophthalmologic information processing device" according to the embodiment. The illumination optical system 20 is an example of an "irradiation optical system" according to the embodiment. The illumination optical system 20, the imaging optical system 50, the control unit 100, and the image forming unit 200 are examples of a "data acquisition unit" according to the embodiment. The first elliptical concave mirror 11 is an example of a "first curved mirror" according to the embodiment. The second elliptical concave mirror 12 is an example of a "second curved mirror" according to the embodiment. The first focus F3 of the second elliptical concave mirror 12 is an example of a "third focus" according to the embodiment. The second focus F4 of the second elliptical concave mirror 12 is an example of a "fourth focus" according to the embodiment.

[0194] <Operation Example> Next, an operation example of the ophthalmologic apparatus 1 according to the embodiment will be described.

[0195] 10 and 11 show an example of operation of the ophthalmologic apparatus 1 according to the embodiment. Fig. 10 shows a flowchart of the example of operation of the ophthalmologic apparatus 1 according to the embodiment. Fig. 11 shows a flowchart of the example of operation of steps S3 and S4 in Fig. 10. The storage unit 120 stores a computer program for realizing the processes shown in Figs. 10 and 11. The main control unit 110 operates in accordance with this computer program to execute the processes shown in Figs. 10 and 11.

[0196] (S1: Obtain diopter) First, the main controller 110 obtains the diopter (refractive index) of the subject's eye E. For example, the main controller 110 obtains the diopter of the subject's eye E from an external ophthalmic measurement device or an electronic medical record. In some embodiments, the main controller 110 controls the moving mechanism 51D that moves the focusing lens 51 to identify the focus state, and determines the diopter from the position on the optical axis of the imaging optical system 50 that is set to the focus state (or the control result of the actuator that drives the moving mechanism 51D).

[0197] (S2: Move the Slit) Next, the main controller 110 changes the position of the slit 22 on the optical axis of the illumination optical system 20 according to the diopter of the eye E obtained in step S1.

[0198] Specifically, the main control unit 110 identifies the position of the slit 22 corresponding to the diopter by referring to the first control information stored in the memory unit 120, and controls the moving mechanism 51D so that the slit 22 is positioned at the identified position.

[0199] (S3: Obtaining the first fundus image) Next, the main control unit 110 controls the light source unit 30 to place the wavelength selection filter 33A in the optical path of the light emitted from the light source 31, thereby sequentially illuminating a predetermined illumination range on the fundus Ef using the slit-shaped first light as illumination light, and obtaining the first fundus image.

[0200] Details of step S3 will be described later.

[0201] (S4: Acquiring a second fundus image) Next, the main control unit 110 controls the light source unit 30 to place the wavelength selection filter 33B in the optical path of the light emitted from the light source 31, thereby sequentially illuminating a predetermined illumination range on the fundus Ef using the slit-shaped second light as illumination light, and acquiring a second fundus image. The illumination range of the fundus Ef in step S4 is the same as the illumination range of the fundus Ef in step S3.

[0202] Details of step S4 will be described later.

[0203] Note that the illumination range of the fundus oculi Ef may be different between steps S3 and S4. In this case, clipping may be performed on at least one of the first and second fundus images, and new first and second fundus images may be acquired from two images representing the same region of the fundus oculi Ef.

[0204] Here, it is preferable to irradiate the fundus with a first light having a central wavelength within the wavelength range of near-infrared light in step S3, and then irradiate the fundus with a second light having a central wavelength within the wavelength range of near-infrared light or red light in step S4, thereby avoiding miosis of the subject's eye and sequentially acquiring the first and second fundus images.

[0205] (S5: Registration Process) Subsequently, the main controller 110 controls the registration processor 211 to execute registration process on the first fundus image acquired in step S3 and the second fundus image acquired in step S4.

[0206] As described above, the registration processing unit 211 aligns the first fundus image and the second fundus image by relatively shifting or rotating the first fundus image and the second fundus image.

[0207] (S6: Generate Calculated Image) Subsequently, the main controller 110 controls the calculated image generator 212 to generate a difference image as a calculated image from the first fundus image and the second fundus image that have been subjected to the registration process in step S5.

[0208] As described above, the calculated image generating unit 212 performs differential processing for each pixel between the pixel values ​​of the first fundus image and the pixel values ​​of the second fundus image, thereby generating a differential image as a calculated image.

[0209] (S7: Complementation processing) Next, the main control unit 110 controls the complementation processing unit 221 to identify defects in a specified part, tissue, or vascular region depicted in the differential image by analyzing the differential image, and to complement the identified defects.

[0210] As described above, the interpolation processing unit 221 executes the interpolation processing for interpolating the defective portion in the difference image.

[0211] (S8: Identifying the Blood Vessel Condition) Next, the main controller 110 controls the blood vessel condition identifying unit 222 to identify the choroidal vessels depicted in the difference image subjected to the interpolation process in step S7 (or the difference image generated in step S6) and to identify the course pattern of the identified choroidal vessels.

[0212] (S9: Determine Symmetry) Next, the main controller 110 controls the symmetry determining unit 223 to execute a process of determining the symmetry of the choroidal blood vessels from the course pattern of the choroidal blood vessels identified in step S8.

[0213] As described above, the symmetry determination unit 223 determines the symmetry of the choroidal blood vessels. The main control unit 110, as a display control unit, can display the determination result obtained by the symmetry determination unit 223 and / or information indicating the degree of symmetry on the display device of the UI unit 80.

[0214] This completes the operation of the ophthalmologic apparatus 1 (END).

[0215] The process of step S3 and the process of step S4 in Fig. 10 are each executed according to the flow shown in Fig. 11. The following mainly describes the case where the process of step S3 is executed, but the process of step S4 is also executed in the same way.

[0216] In steps S3 and S4, the main controller 110 can control a fixation projection system (not shown) to start projecting a fixation light beam onto the fundus Ef of the subject's eye E.

[0217] (S11: Irradiating Illumination Light) In step S3, the main control unit 110 controls the illumination optical system 20 to start irradiating the slit-shaped first light as illumination light.

[0218] That is, the main control unit 110 starts deflection control of the optical scanner 40 with respect to the slit-shaped first light generated by the illumination optical system 20, thereby starting irradiation of the slit-shaped first light onto a desired illumination range on the fundus Ef of the subject's eye E. When irradiation of the illumination light starts, the slit-shaped illumination light is sequentially irradiated within the desired illumination range as described above.

[0219] (S12: Obtaining light reception results) The main controller 110 obtains light reception results of pixels in the aperture range of the first image sensor 71A (in the case of step S4, the second image sensor 71B) corresponding to the irradiation area of ​​the illumination light on the fundus Ef in step S12.

[0220] (S13: Next Irradiation Position?) The main controller 110 determines whether there is a next irradiation position to be irradiated with illumination light. The main controller 110 can determine whether there is a next irradiation position to be irradiated with illumination light by determining whether the illumination range of the illumination light, which is sequentially moved, has covered a predetermined fundus photography range.

[0221] If it is determined that there is a position to be illuminated next with illumination light (S13: Y), the process of step S3 proceeds to step S14. If it is determined that there is no position to be illuminated next with illumination light (S13: N), the process of step S3 proceeds to step S15.

[0222] (S14: Changing the deflection angle of the illumination light) When it is determined in step S13 that there is a position to be illuminated next with the illumination light (S13: Y), the main control unit 110 controls the optical scanner 40 to change the deflection angle of the deflection surface of the optical scanner 40 by a predetermined angle.

[0223] Following step S14, the process of step S3 proceeds to step S11.

[0224] (S15: Forming an image) In step S13, when it is determined that there is no irradiation position to be irradiated with illumination light next (S13: N), the main control unit 110 causes the image forming unit 200 to form a first fundus image (in the case of step S4, a second fundus image) from the light reception results repeatedly acquired while changing the irradiation area of ​​the illumination light on the fundus Ef in steps S11 to S14.

[0225] For example, the image forming unit 200 combines a plurality of light receiving results, each of which has a different illumination light irradiation area (opening range on the light receiving surface of the first image sensor 71A) for the number of times the processes of steps S11 to S14 are repeated, based on the order of movement of the irradiation area, thereby forming one frame of a first fundus image of the fundus Ef of the subject's eye E.

[0226] In some embodiments, in step S15, illumination light is applied to an illumination region that is set so as to provide an overlapping region with an adjacent illumination region, and thus, in step S15, images are combined so that the overlapping regions overlap each other to form one frame of a fundus image.

[0227] This completes the process of step S3 (or step S4) in FIG. 10 (END).

[0228] As described above, according to the embodiment, wide-angle first and second fundus images can be acquired by irradiating the fundus Ef with slit-shaped first and second lights having different center wavelengths as illumination light, and wide-angle calculated images (difference images) can be acquired from the first and second fundus images. This makes it possible to acquire a difference image depicting the distribution of integrated values ​​of reflection intensity for each pixel in a depth range between the deepest depth position corresponding to the penetration depth of the first light and the deepest depth position corresponding to the penetration depth of the second light, without using a contrast agent or requiring a long scanning time. As a result, a front image representing the structure of the fundus in a desired depth range can be easily acquired without imposing a burden on the subject.

[0229] [First Modification] In the above embodiment, a case has been described in which the first light and the second light are sequentially irradiated onto the fundus Ef by selectively arranging one or more wavelength-selective filters in the optical path of light emitted from a single light source, but the configuration according to the embodiment is not limited to this. For example, the first light and the second light may be sequentially irradiated onto the fundus Ef using a plurality of light sources.

[0230] The first modification of the embodiment will be described below, focusing on the differences from the embodiment.

[0231] Fig. 12 shows an example of the configuration of a light source unit 30 according to a first modified example of the embodiment. In Fig. 12, the same parts as in Fig. 2 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0232] The light source unit 30 according to this modification includes a first light source 31A, a second light source 31B, a projection lens 32, and a dichroic mirror 34.

[0233] The first light source 31A emits light in a wavelength range having a first wavelength λ1 as the center wavelength. The second light source 31B emits light in a wavelength range having a second wavelength λ2 as the center wavelength. The dichroic mirror 34 is configured to reflect the light emitted from the first light source 31A and guide it to the projection lens 32, and to transmit the light emitted from the second light source 31B and guide it to the projection lens 32.

[0234] The first light source 31A and the second light source 31B are exclusively controlled by the control unit 100 (main control unit 110) so that one of them is turned on. That is, when the control unit 100 sets the first light source 31A to on and the second light source 31B to off, light emitted from the first light source 31A is reflected by the dichroic mirror 34, passes through the projection lens 32, and is emitted as the first light. On the other hand, when the control unit 100 sets the first light source 31A to off and the second light source 31B to on, light emitted from the second light source 31B passes through the dichroic mirror 34, passes through the projection lens 32, and is emitted as the second light.

[0235] As described above, according to this modification, by controlling the first light source 31A and the second light source 31B instead of controlling the wavelength-selective filters 33A and 33B, it is possible to irradiate the fundus Ef with slit-shaped first and second lights having different center wavelengths as illumination light, as in the embodiment. This makes it possible to acquire wide-angle first and second fundus images, and to acquire wide-angle calculated images (difference images) from the first and second fundus images. As a result, it is possible to easily acquire a front image that represents the structure of the fundus Ef in a desired depth range without imposing a burden on the subject.

[0236] [Second Modification] In the above embodiment and its first modification, the first light and the second light are switched and sequentially irradiated onto the fundus Ef by controlling the wavelength-selective filters 33A, 33B or the first light source 31A and the second light source 31B. However, the configuration according to the embodiment is not limited to this. For example, the first light and the second light may be sequentially irradiated onto the fundus Ef using a single light source that can switch between and output two or more light beams having different center wavelengths.

[0237] The second modification of the embodiment will be described below, focusing on the differences from the embodiment.

[0238] Fig. 13 shows a configuration example of a light source unit 30 according to a second modified example of the embodiment. In Fig. 13, the same parts as those in Fig. 2 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0239] The light source unit 30 according to this modification includes a light source 31C and a projection lens 32 .

[0240] The light source 31C can switch between outputting light in a wavelength range having a first wavelength λ1 as the center wavelength and light in a wavelength range having a second wavelength λ2 as the center wavelength. The light emitted from the light source 31C passes through the projection lens 32 and is emitted as the first light or the second light. Such a light source 31C may be a wavelength swept light source.

[0241] As described above, according to this modification, by controlling the light source 31C instead of the wavelength-selective filters 33A and 33B, it is possible to irradiate the fundus Ef with slit-shaped first and second lights having different center wavelengths as illumination light, as in the embodiment. This makes it possible to acquire wide-angle first and second fundus images, and to acquire wide-angle calculated images (difference images) from the first and second fundus images. As a result, it is possible to easily acquire a front image that represents the structure of the fundus Ef in a desired depth range without imposing a burden on the subject.

[0242] [Third Modification] In the above embodiment, its first modification, and its second modification, the case where the first light and the second light having different center wavelengths are sequentially irradiated onto the fundus oculi Ef has been described, but the configuration according to the embodiment is not limited to this. For example, the first light and the second light having different center wavelengths may be irradiated onto the fundus oculi Ef simultaneously, the first fundus image and the second fundus image may be acquired simultaneously, and a calculated image may be generated from the acquired first fundus image and the second fundus image.

[0243] The third modification of the embodiment will be described below, focusing on the differences from the embodiment.

[0244] In this modification, the light source unit 30 is configured to simultaneously irradiate the fundus oculi Ef with first light and second light having different center wavelengths. For example, the light source unit 30 has the configuration shown in Fig. 12. In this case, by simultaneously turning on the first light source 31A and the second light source 31B by the control unit 100, the light source unit 30 can emit light in a wavelength range that includes the first wavelength λ1 and the second wavelength λ2 as illumination light.

[0245] The imaging device 70 can simultaneously receive the returning light of the first light by the first image sensor 71A and the returning light of the second light by the second image sensor 71B.

[0246] As described above, according to this modification, instead of controlling the wavelength-selective filters 33A and 33B, the first light source 31A and the second light source 31B are controlled to be turned on simultaneously. As a result, similar to the embodiment, slit-shaped first and second lights having different center wavelengths can be irradiated onto the fundus Ef as illumination light. Therefore, according to this modification, wide-angle first and second fundus images can be acquired, and wide-angle calculated images (difference images) can be acquired from the first and second fundus images. As a result, a front image representing the structure of the fundus within a desired depth range can be easily acquired without imposing a burden on the subject.

[0247] [Fourth Modification] In the above embodiment and its first to third modifications, the first image sensor 71A and the second image sensor 71B receive the return light of the first light and the return light of the second light, but the configuration according to the embodiment is not limited to this. For example, the return light of the first light and the return light of the second light may be received by a single image sensor.

[0248] The fourth modification of the embodiment will be described below, focusing on the differences from the embodiment.

[0249] In this modification, the light source unit 30 is configured to sequentially or simultaneously irradiate the fundus Ef with first light and second light having different center wavelengths. When the first light and second light are sequentially irradiated onto the fundus Ef, the light source unit 30 has the same configuration as in the embodiment, the first modification, or the second modification. When the first light and second light are simultaneously irradiated onto the fundus Ef, the light source unit 30 has the same configuration as in the third modification.

[0250] The imaging device 70 according to this modification includes an imaging lens and a two-dimensional image sensor. A plurality of detection elements (imaging elements, or more broadly, pixels) having wavelength sensitivity characteristics capable of detecting light of a first wavelength λ1 and light of a second wavelength λ2 are arranged one-dimensionally or two-dimensionally on the light receiving surface of the two-dimensional image sensor.

[0251] Fig. 14 is a schematic diagram showing an example of the configuration of the light receiving surface of an image sensor according to a fourth modified example of the embodiment, as viewed from above.

[0252] The image sensor according to this modification is configured to be capable of detecting visible light (e.g., red light) and near-infrared light. Such an image sensor has four types of detection elements regularly arranged two-dimensionally (RGB-IR format). The four types of detection elements include a first detection element R, a second detection element G, a third detection element B, and a fourth detection element IR. The first detection element R is a detection element having a peak in its wavelength sensitivity characteristic in the wavelength range of red light (R). The second detection element G is a detection element having a peak in its wavelength sensitivity characteristic in the wavelength range of green light (G). The third detection element B includes a detection element having a peak in its wavelength sensitivity characteristic in the wavelength range of blue light (B). The fourth detection element IR is a detection element having a peak in its wavelength sensitivity characteristic in the wavelength range of near-infrared light (IR).

[0253] That is, the image sensor according to this modification includes an array of first detection elements R and fourth detection elements IR. The first detection elements R have wavelength sensitivity characteristics in which their detection sensitivity at the second wavelength λ2 is higher than their detection sensitivity at the first wavelength λ1. The fourth detection elements IR have wavelength sensitivity characteristics in which their detection sensitivity at the first wavelength λ1 is higher than their detection sensitivity at the second wavelength λ2.

[0254] In this modified example, when the first light and the second light are simultaneously irradiated onto the fundus Ef, the return light of the first light and the return light of the second light from the fundus Ef are simultaneously received by an image sensor having the configuration shown in Fig. 14. The control unit 100 (main control unit 110) can read out the light reception results of the multiple fourth detection elements IR as the light reception results of the return light of the first light. In addition, the control unit 100 can read out the light reception results of the multiple first detection elements R as the light reception results of the return light of the second light.

[0255] Fig. 15 is a schematic diagram showing another example of the configuration of the light receiving surface of the image sensor according to the fourth modified example of the embodiment, as viewed from above.

[0256] The image sensor shown in Fig. 15 is also configured to be able to detect visible light and near-infrared light. This image sensor also has four types of detection elements regularly arranged two-dimensionally, similar to the image sensor shown in Fig. 14. The image sensor shown in Fig. 15 has a larger number of second detection elements G than the image sensor configuration shown in Fig. 14.

[0257] In the configuration shown in Figure 15, as in the configuration shown in Figure 14, by selectively reading out the light reception results from multiple detection elements arranged in the image sensor, it is possible to simultaneously receive the return light of the first light and the return light of the second light that are simultaneously irradiated onto the fundus Ef.

[0258] As described above, according to this modification, similar to the embodiment, it is possible to acquire first and second wide-angle fundus images and then acquire a wide-angle calculated image (difference image) from the first and second fundus images, thereby easily acquiring a front image that represents the structure of the fundus in a desired depth range without imposing a burden on the subject.

[0259] The image sensor shown in Fig. 14 or 15 may be configured so that the arrangement of the four types of detection elements can be changed depending on the tissue characteristics of the imaging target. Alternatively, two or more image sensors with different arrangements of the four types of detection elements can be selectively arranged at the position of the image sensor shown in Fig. 14 or 15 depending on the tissue characteristics of the imaging target.

[0260] [Fifth Modification] In the above embodiment and its first to fourth modifications, the case where the timing of irradiation of the first light and the timing of irradiation of the second light are controlled in terms of time has been described, but the configuration of the embodiment is not limited to this. For example, the first light and the second light may be spatially controlled to acquire the first fundus image and the second fundus image according to the embodiment using a slit scan method, and a calculated image (difference image) may be generated from the acquired first fundus image and second fundus image.

[0261] The fifth modification of the embodiment will be described below, focusing on the differences from the embodiment.

[0262] The ophthalmologic apparatus according to this modification is configured to illuminate the fundus Ef using a slit scan method in which an illumination area of ​​the first light and an illumination area of ​​the second light are spatially separated within an illumination range of the fundus Ef, and to receive return light of the first light and return light of the second light from the fundus Ef. In this case, the photographing optical system 50 according to this modification includes a single image sensor capable of detecting light of the first wavelength λ1 and the second wavelength λ2, and is configured to read out the light reception results of the return light of the first light and the light reception results of the return light of the second light using a global shutter method. For example, the light reception results are captured from each of the light reception areas of the return light of the first light and the light reception area of ​​the return light of the second light, which are spatially separated from each other in the image sensor.

[0263] The light source unit 30 according to this modification is configured to simultaneously emit a first light in a first wavelength range having a first wavelength λ1 as a center wavelength and a second light in a second wavelength range having a second wavelength λ2 as a center wavelength. Such a light source unit 30 includes a light source and a projection lens. In this case, the light source emits light in a wavelength range including the first wavelength λ1 and the second wavelength λ2. The light source includes, for example, a light-emitting diode (LED), a laser diode (LD), a halogen lamp, or a xenon lamp. In some embodiments, the light source includes a white light source or a light source capable of outputting light of each of the RGB color components.

[0264] 16 shows an example of the configuration of the slit 22 according to the fifth modified example of the embodiment. FIG. 16 is a schematic diagram showing the configuration of the slit 22 as viewed from the optical axis direction of the illumination optical system 20.

[0265] The slit 22 according to this modification has a first opening 22a and a second opening 22b. A wavelength-selecting filter 24a is provided in the first opening 22a. A wavelength-selecting filter 24b is provided in the second opening 22b. The wavelength-selecting filter 24a is configured to transmit light in a wavelength range having a first wavelength λ1 as its center wavelength and to block light in other wavelength ranges. The wavelength-selecting filter 24b is configured to transmit light in a wavelength range having a second wavelength λ2 as its center wavelength and to block light in other wavelength ranges.

[0266] As a result, the first irradiation area of ​​the first light is simultaneously illuminated as a slit image, which is an image of the first opening 22a, and the second irradiation area of ​​the second light is simultaneously illuminated as a slit image, which is an image of the second opening 22b, in the illumination range of the fundus Ef.

[0267] Fig. 17 is an explanatory diagram of the timing of acquiring the first fundus image and the second fundus image by the illumination control unit 111 and the light receiving control unit 112 according to the fifth modified example of the embodiment. Fig. 17 schematically shows an illumination area IP1 of the slit-shaped first light and an illumination area IP2 of the slit-shaped second light that are irradiated onto the fundus Ef at time t1, and virtual aperture ranges OP1 and OP2 on the light receiving surface SR of the image sensor.

[0268] For example, the irradiation control unit 111 according to this modification controls the light source unit 30 to generate illumination light including slit-shaped first light and second light from light in a wavelength range including a first wavelength λ1 and a second wavelength λ2, and deflects the generated slit-shaped illumination light using the optical scanner 40. As a result, an irradiation area IP1 of the slit-shaped first light and an irradiation area IP2 of the slit-shaped second light are moved in a direction perpendicular to the slit direction on the fundus Ef (from time t1 to time t2).

[0269] On the light receiving surface SR of the image sensor according to this modified example, the light receiving control unit 112 according to this modified example changes the pixels to be read line by line, thereby setting virtual opening ranges OP1 and OP2. The opening range OP1 is desirably wider than the light receiving area IP1' or light receiving area IP1' of the light receiving surface SR that can receive the returned light of the illumination light. The opening range OP2 is desirably wider than the light receiving area IP2' or light receiving area IP2' of the light receiving surface SR that can receive the returned light of the illumination light. The light receiving control unit 112 controls the movement of the opening ranges OP1 and OP2 in synchronization with the movement control of the illumination light irradiation areas IP1 and IP2 (from time t1 to time t2).

[0270] As described above, the illumination optical system according to this modification includes a slit disposed at a position substantially optically conjugate with the fundus, the slit having a first opening through which the first light passes and a second opening through which the second light passes. The imaging optical system according to this modification includes an image sensor configured to receive, in each of two light-receiving regions spatially separated on the light-receiving surface, return light of the first light from an illumination region on the fundus corresponding to the first opening and return light of the second light from an illumination region on the fundus corresponding to the second opening.

[0271] Even with this configuration, it is possible to obtain high-quality images (first fundus image, second fundus image) of the fundus Ef with strong contrast using a simple configuration without being affected by unnecessary scattered light. Furthermore, since the first light and the second light can be irradiated onto the fundus simultaneously, the imaging time can be shortened, and the burden on the subject can be further reduced.

[0272] [Sixth Modification] In the above embodiment and its first to fifth modifications, a case has been mainly described in which a first light having a center wavelength in the wavelength range of near-infrared light and a second light having a center wavelength in the wavelength range of red light are used, but the configuration of the embodiment is not limited to this.

[0273] The first wavelength λ1 and the second wavelength λ2 can be determined by taking into account the redox reaction of hemoglobin so as to enhance the contrast between arterial and venous blood vessels. In this case, hemoglobin includes oxyhemoglobin, which is abundant in arterial blood vessels, and deoxyhemoglobin, which is abundant in venous blood vessels. Therefore, the first wavelength λ1 is set to a wavelength of 800 nm or more (e.g., 850 nm), and the second wavelength λ2 is set to a wavelength of less than 800 nm (e.g., 760 nm) (see, for example, Onisako, "Study on Visualization of Hemoglobin Concentration Distribution Using Near-Infrared Light Reflection Dynamic Images," Transactions of the Visualization Society of Japan, October 2011, Vol. 31, No. 10, pp. 57-61). This enhances the contrast between oxyhemoglobin and deoxyhemoglobin.

[0274] For example, hemoglobin has an absorption peak around 580 nm. In this case, one of the first wavelength λ1 and the second wavelength λ2 is set to 580 nm (i.e., the wavelength range of green light), and the other of the first wavelength λ1 and the second wavelength λ2 is set to light in another wavelength range (e.g., the wavelength range of red light or near-infrared light). This makes it possible to acquire a calculated image in which the contrast between blood vessels and other tissues is enhanced. For example, by irradiating the fundus with first light in the wavelength range of near-infrared light and then irradiating the fundus with second light in the wavelength range of green light, it is possible to acquire a calculated image while avoiding miosis.

[0275] Soft exudates may be observed in fundus images of eyes with diabetic retinopathy, hypertensive retinopathy, retinal vein occlusion, etc. Soft exudates are cotton-like white lesions caused by localized ischemia (insufficient blood flow) in the nerve fiber layer of the retina, resulting from edema of nerve fibers due to axonal traffic disruption. Soft exudates strongly scatter light in the short wavelength range (blue light wavelength range). Therefore, by setting one of the first wavelength λ1 and the second wavelength λ2 to a wavelength in the short wavelength range and the other of the first wavelength λ1 and the second wavelength λ2 to a wavelength other than the short wavelength range, images depicting soft exudates can be easily obtained.

[0276] Hard exudates are yellow or white lesions caused by the deposition of lipids and proteins leaking from subretinal blood vessels and resulting from increased vascular permeability. The deposited yellow lipid and protein particles tend to absorb light in the short wavelength range. Therefore, by setting one of the first wavelength λ1 and the second wavelength λ2 to a wavelength in the short wavelength range and the other of the first wavelength λ1 and the second wavelength λ2 to a wavelength other than the short wavelength range, images depicting hard exudates can be easily obtained.

[0277] The macular region contains a high concentration of macular pigment. The relationship between the density of this macular pigment and the incidence of age-related macular degeneration has been attracting attention. Macular pigment contains at least two types of xanthophyll pigments, such as lutein and zeaxanthin, and has an absorption peak at 460 nm. For example, one of the first wavelength λ1 and the second wavelength λ2 is a wavelength less than 460 nm, and the other of the first wavelength λ1 and the second wavelength λ2 is a wavelength equal to or greater than 460 nm. This results in different pigment distributions in the macular region between the first and second fundus images, and by analyzing the difference between these images, an image depicting the distribution of macular pigment can be easily obtained.

[0278] The light absorption spectrum of retinal pigment epithelial (RPE) cells, which form the retinal pigment epithelium layer, is characterized primarily by the abundant melanin pigment present within the cells and the lipofuscin accumulated within the cells. Melanin pigments strongly absorb light in the short wavelength range. Here, light in the short wavelength range refers to light in the wavelength range (200 nm to 480 nm) from the ultraviolet wavelength range (200 nm to 400 nm) to the visible blue wavelength range (400 nm to 480 nm). Lipofuscin also particularly absorbs light in the short wavelength range. For example, one of the first wavelength λ1 and the second wavelength λ2 is a wavelength within the short wavelength range, and the other of the first wavelength λ1 and the second wavelength λ2 is a wavelength outside the short wavelength range. This allows for easily obtaining arithmetic images in the first and second fundus images that depict areas where light is absorbed by the melanin pigment and lipofuscin that characterize RPE cells, as well as other areas. For example, since the amount of melanin pigment and lipofuscin changes depending on the subject's age and disease, it may be possible to easily determine the possibility of disease while taking age into consideration using calculated images.

[0279] [Seventh Modification] In the above embodiment and its first to sixth modifications, the ophthalmologic apparatus according to the embodiment implements the functions of the ophthalmologic information processing apparatus according to the embodiment, but the configuration according to the embodiment is not limited to this. For example, the ophthalmologic information processing apparatus according to the embodiment may be provided outside the ophthalmologic apparatus.

[0280] The seventh modification of the embodiment will be described below, focusing on the differences from the embodiment.

[0281] FIG. 18 shows a block diagram of an example of the configuration of an ophthalmologic system according to the seventh modification of the embodiment.

[0282] The ophthalmologic system 1000 according to this modification includes an ophthalmologic apparatus 300 , an ophthalmologic information-processing apparatus 400 , an operation apparatus 500 , and a display apparatus 600 .

[0283] The ophthalmologic apparatus 300 acquires image data of a first fundus image and image data of a second fundus image according to the embodiment, and transmits the acquired image data of the first fundus image and image data of the second fundus image to the ophthalmologic information processing apparatus 400. The ophthalmologic information processing apparatus 400 performs the above-described image comparison processing based on the image data of the first fundus image and the image data of the second fundus image acquired by the ophthalmologic apparatus 300, and generates a calculated image (e.g., a difference image) of the first fundus image and the second fundus image. The ophthalmologic information processing apparatus can perform the above-described analysis processing on the generated calculated image.

[0284] The operation device 500 receives operation contents from a user such as a doctor for controlling the operation of the ophthalmologic information-processing device 400, and outputs an operation instruction signal corresponding to the operation contents. The ophthalmologic information-processing device 400 controls the inside of the device based on the operation instruction signal from the operation device 500. The display device 600 displays at least one of the first fundus image and the second fundus image acquired by the ophthalmologic device 300, and the processing results (including a calculated image and an analytical processing result) executed by the ophthalmologic information-processing device 400.

[0285] The operation device 500 and the display device 600 may be a single device that realizes the functions of both.

[0286] FIG. 19 is a block diagram showing an example of the configuration of the ophthalmologic apparatus 300 shown in FIG.

[0287] The ophthalmologic apparatus 300 includes an optical system 310 , a control unit 320 , and a communication unit 330 .

[0288] The optical system 310 includes the optical system of Fig. 1. That is, the optical system 310 includes the objective optical system 10, the illumination optical system 20 (including the optical scanner 40), the imaging optical system 50, and the optical path separating member 60.

[0289] The control unit 320 controls the optical system 310 and the communication unit 330. The control unit 320 controls the optical system 310 to acquire a first fundus image and a second fundus image of the fundus Ef, similar to the embodiment or its modified example. That is, the control unit 320 controls the optical system 310 to sequentially or simultaneously irradiate the fundus Ef of the subject's eye E with the first light and the second light, and to acquire the first fundus image and the second fundus image by receiving the return light of the first light and the return light of the second light from the fundus Ef. The control unit 320 controls the communication unit 330 to transmit image data of the acquired first fundus image and image data of the acquired second fundus image to the ophthalmologic information processing device 400. Such functions of the control unit 320 are realized by one or more processors.

[0290] The communication unit 330 performs interface processing with the ophthalmologic information-processing device 400 via a wired or wireless communication path. The communication unit 330 is controlled by the control unit 320 and transmits and receives data to and from the ophthalmologic information-processing device 400.

[0291] FIG. 20 is a block diagram showing an example of the configuration of the ophthalmologic information-processing device 400 shown in FIG.

[0292] The ophthalmological information processing device 400 includes an ophthalmological information processing unit 410 , a control unit 420 , and a communication unit 430 .

[0293] The ophthalmologic information processing unit 410 realizes the functions of the data processing unit 210 according to the embodiment.

[0294] Fig. 21 is a block diagram showing an example of the configuration of the ophthalmologic information processing unit 410 shown in Fig. 20. In Fig. 21, the same components as those in Fig. 6 are denoted by the same reference numerals, and the description thereof will be omitted where appropriate.

[0295] The ophthalmological information processing unit 410 includes a registration processing unit 211, a calculated image generating unit 212, and an analyzing unit 220. The analyzing unit 220 includes a complementing processing unit 221, a vascular state specifying unit 222, and a symmetry determining unit 223, similar to that in FIG.

[0296] That is, the ophthalmological information processing unit 410 performs registration processing on the first fundus image and the second fundus image based on image data of the first fundus image and the second fundus image acquired from the ophthalmological apparatus 300 via the communication unit 430. The ophthalmological information processing unit 410 generates a calculated image (e.g., a difference image) from the first fundus image and the second fundus image to be aligned. The ophthalmological information processing unit 410 can perform the above-described analysis processing on the generated calculated image. The functions of the ophthalmological information processing unit 410 are realized by one or more processors. For example, the functions of the ophthalmological information processing unit 410 are realized by multiple processors. In this case, each processor is configured to realize the functions of each unit in FIG. 21 .

[0297] The control unit 420 controls the ophthalmological information processing unit 410 and the communication unit 430. The control unit 420 controls the communication unit 430 to receive image data of the first fundus image and the second fundus image acquired by the ophthalmological apparatus 300. The control unit 420 controls the ophthalmological information processing unit 410 to perform registration processing on the acquired first fundus image and the second fundus image to generate a calculated image, as in the embodiment or its modification. The control unit 420 also controls the ophthalmological information processing unit 410 to perform the above-mentioned analysis processing on the calculated image, as in the embodiment or its modification. Such functions of the control unit 420 are realized by a processor.

[0298] The communication unit 430 performs interface processing with the ophthalmic apparatus 300 (communication unit 330) via a wired or wireless communication path. The communication unit 430 is controlled by the control unit 420 and transmits and receives data to and from the ophthalmic apparatus 300.

[0299] The communication unit 430 is an example of a "data acquisition unit" according to the embodiment. The ophthalmological information processing unit 410 is an example of an "ophthalmological information processing device" according to the embodiment.

[0300] [Others] In the above embodiment and its modified examples, the first fundus image and the second fundus image are mainly acquired by the slit scan method, but the embodiment and its modified examples are not limited to this. In some embodiments, each of the first fundus image and the second fundus image may be acquired by flash photography in which the imaging range (illumination range) is illuminated with illumination light only once.

[0301] In the above embodiment and its modified examples, the case where the choroidal vascular region is extracted from the subretinal tissue has been mainly described, but the embodiment and its modified examples are not limited to this. For example, the first wavelength λ1 and the second wavelength λ2 can be selected by focusing on the absorption peak of a pigment specific to a fundus disease.

[0302] Furthermore, by adopting a wavelength having a depth of penetration near the upper layer of the sclera as the first wavelength λ1 and a wavelength having a depth of penetration near the lower layer of the sclera as the second wavelength λ2, it is also possible to obtain a calculated image (e.g., a difference image) that depicts the shape of the sclera.

[0303] Similarly, it is also possible to obtain computed images depicting abnormal retinal vascular networks, which are useful in detecting early signs of age-related macular degeneration.

[0304] Furthermore, it is also possible to acquire a calculated image that depicts not only the lower layer region of the retina but also the corneal scleral boundary of the anterior segment of the eye and the skeleton of the ciliary body region.

[0305] In the above embodiment and its modified examples, two types of fundus images are acquired using two types of light with different center wavelengths. However, the configuration of the embodiment is not limited to this. For example, three or more types of fundus images may be acquired using three or more types of light with different center wavelengths, and a difference image may be generated using any two of the fundus images. In this case, the three or more center wavelengths may be wavelengths with equal wavelength intervals or wavelengths that are preset for each tissue or region.

[0306] In the above embodiment and its modified example, a case has been described in which a calculated image is generated from two or more images formed from the results of receiving two or more return beams of two or more light beams irradiated onto the fundus, but the configuration according to the embodiment is not limited to this. For example, a calculated image may be generated from the processing results obtained by performing a comparison calculation process (such as a difference process) similar to the image comparison process on the results of receiving two or more return beams.

[0307] [Operation] An ophthalmological information processing apparatus, an ophthalmological apparatus, an ophthalmological information processing method, and a program according to the embodiment will be described.

[0308] A first aspect of the embodiment is an ophthalmological information processing device (data processing unit 210, ophthalmological information processing unit 410) including a data acquisition unit (illumination optical system 20, imaging optical system 50, control unit 100, and image forming unit 200, or communication unit 430) and a calculated image generation unit (212). The data acquisition unit acquires image data of two or more fundus images obtained by irradiating two or more lights onto the fundus (Ef) of the subject's eye (E). The calculated image generation unit generates a calculated image by performing image comparison processing on the two or more fundus images based on the image data of the two or more fundus images.

[0309] According to this aspect, it is possible to easily obtain a calculated image that depicts a contrast difference due to differences in imaging, without using a contrast agent or requiring a long scan time, and as a result, it is possible to easily obtain an image that shows the subretinal structure, without imposing a burden on the subject.

[0310] In a second aspect of the embodiment, in the first aspect, the data acquisition unit acquires first image data of a first fundus image obtained by irradiating the fundus with first light and second image data of a second fundus image obtained by irradiating the fundus with second light. The calculated image generation unit performs image comparison processing on the first fundus image and the second fundus image based on the first image data and the second image data.

[0311] According to this aspect, it is possible to easily obtain a calculated image that depicts the contrast difference resulting from the difference in imaging using two types of light, without using a contrast agent or requiring a long scan time.

[0312] In a third aspect of the embodiment, in the second aspect, the first light is light having a first wavelength as a center wavelength, and the second light is light having a second wavelength as a center wavelength that is different from the first wavelength in at least one of the depth of penetration into the fundus and the light reaction characteristic.

[0313] According to this aspect, the fundus is irradiated with light having different depths of penetration and / or different light response characteristics to obtain a calculated image, thereby making it possible to easily obtain an image representing the subretinal structure.

[0314] In a fourth aspect of the embodiment, in the third aspect, the first wavelength is a wavelength within the wavelength range of near-infrared light, and the second wavelength is a wavelength within the wavelength range of near-infrared light or a wavelength within the wavelength range of red light.

[0315] According to this aspect, the calculated image is an image projected for each pixel in the depth range between the depth position reached by light in the red wavelength range and the depth position reached by light in the infrared wavelength range, thereby making it possible to easily obtain a calculated image depicting the choroidal vascular region without using a contrast agent or requiring a long scanning time.

[0316] In a fifth aspect of the embodiment, the first wavelength of the third aspect is a wavelength within the wavelength range of red light, and the second wavelength is a wavelength within the wavelength range of green light.

[0317] According to this aspect, it is possible to obtain a computed image in which the contrast of arterial blood vessels and venous blood vessels is enhanced by focusing on the redox reaction of hemoglobin.

[0318] In a sixth aspect of the embodiment, in the second aspect, the first light is light having a first wavelength in a wavelength range including an absorption peak wavelength of a predetermined site or tissue on the fundus, and the second light is light having a second wavelength different from the first wavelength.

[0319] According to this aspect, it is possible to obtain a calculated image that depicts the contrast difference resulting from the difference between the absorption peak of the first light and the absorption peak of the second light, without using a contrast agent or requiring a long scan time.

[0320] A seventh aspect of the embodiment is any of the first to sixth aspects, further including a registration processing unit (211) that performs registration processing on two or more fundus images. The calculated image generating unit generates a calculated image from the two or more fundus images obtained by the registration processing.

[0321] According to this aspect, it is possible to prevent degradation in the image quality of the calculated image in which the contrast difference resulting from the difference in imaging using two types of light is depicted.

[0322] An eighth aspect of the embodiment is any one of the first to sixth aspects, further comprising a complementation processing unit (221) that complements a defective portion of the calculated image.

[0323] According to this aspect, it is possible to easily obtain a calculated image in which the defective portion is complemented.

[0324] In a ninth aspect of the embodiment, in the eighth aspect, the complementation processing unit complements defective portions of the calculated image using a trained model obtained by performing machine learning in advance on the input calculated image to complement defective portions.

[0325] According to this aspect, a calculated image in which defects are complemented can be easily obtained using a trained model.

[0326] A tenth aspect of the embodiment is an ophthalmologic apparatus (1) including an irradiation optical system (illumination optical system 20), an imaging optical system (50), a control unit (100), and an ophthalmologic information processing device (data processing unit 210) of any one of the first to sixth aspects. The irradiation optical system irradiates two or more beams of light onto the fundus. The imaging optical system receives two or more return beams of the two or more beams from the fundus. The control unit controls the irradiation optical system to control the timing of irradiation of the two or more beams of light, and also controls the imaging optical system to control the timing of reception of the two or more return beams in synchronization with the irradiation timing. The ophthalmologic information processing device acquires image data of two or more fundus images formed based on the two or more return beams.

[0327] According to this aspect, an ophthalmic device can be provided that can easily obtain a calculated image that depicts contrast differences caused by imaging differences, without using contrast agents or requiring long scanning times.

[0328] In an eleventh aspect of the embodiment, in the tenth aspect, the irradiation optical system irradiates the fundus with first light and second light. The photographing optical system receives return light of the first light and return light of the second light. The control unit controls the irradiation optical system to control the irradiation timing of the first light and the second light, and controls the photographing optical system to control the reception timing of the return light of the first light and the return light of the second light in synchronization with the irradiation timing. The ophthalmologic information processing device acquires first image data of a first fundus image formed based on the return light of the first light and second image data of a second fundus image formed based on the return light of the second light.

[0329] According to this aspect, it is possible to provide an ophthalmic device that can easily obtain a calculated image that depicts the contrast difference resulting from the difference in imaging using two types of light, without using a contrast agent or requiring a long scanning time.

[0330] In a twelfth aspect of the embodiment, in the eleventh aspect, the control unit controls the irradiation optical system so as to repeatedly irradiate the first light and the second light onto the fundus.

[0331] According to this aspect, by repeatedly irradiating the fundus with the first light and the second light, it is possible to easily obtain a calculated image that depicts a contrast difference resulting from the difference in imaging using the two lights, thereby making it possible to more easily obtain a calculated image by utilizing the configuration of an existing optical system.

[0332] In a thirteenth aspect of the embodiment, in the eleventh aspect, the control unit controls the irradiation optical system so as to simultaneously irradiate the fundus with the first light and the second light.

[0333] According to this aspect, by simultaneously irradiating the fundus with the first light and the second light, it is possible to easily obtain a calculated image that depicts a contrast difference resulting from the difference in imaging using the two lights, thereby shortening the imaging time and further reducing the burden on the subject.

[0334] In a fourteenth aspect of the embodiment, in the eleventh aspect, the irradiation optical system includes a light source (31) and one or more wavelength-selective filters (33A, 33B, 24a, 24b) selectively positionable on an optical path of light from the light source, and the control unit selectively inserts or removes the one or more wavelength-selective filters on the optical path.

[0335] According to this aspect, it is possible to generate two or more lights with a simple configuration and irradiate the two or more generated lights onto the fundus.

[0336] In a fifteenth aspect of the embodiment, in the eleventh aspect, the photographing optical system includes a first image sensor (71A) that receives the returning light of the first light, and a second image sensor (71B) that receives the returning light of the second light.

[0337] According to this aspect, with a simple configuration and control, the first light and the second light can be irradiated onto the fundus simultaneously or sequentially, and a calculated image can be acquired.

[0338] In a sixteenth aspect of the embodiment, in the eleventh aspect, the photographing optical system includes an image sensor in which a detection element has a wavelength sensitivity characteristic in which the detection sensitivity at a first wavelength that is the center wavelength of the first light is higher than the detection sensitivity at a second wavelength that is the center wavelength of the second light, and a detection element has a wavelength sensitivity characteristic in which the detection sensitivity at the second wavelength is higher than the detection sensitivity at the first wavelength.

[0339] According to this aspect, it is possible to simultaneously or sequentially irradiate the first light and the second light onto the fundus and acquire a calculated image with a simple configuration.

[0340] In a seventeenth aspect of the embodiment, in the eleventh aspect, the illumination optical system is configured to illuminate the fundus with a slit-shaped first light and a slit-shaped second light, and the photographing optical system is configured to capture a result of receiving return light of the first light in a light-receivable area on the fundus corresponding to an irradiation area of ​​the first light, and to capture a result of receiving return light of the second light in a light-receivable area on the fundus corresponding to an irradiation area of ​​the second light.

[0341] According to this aspect, it is possible to easily acquire a calculated image by a slit scanning method using the first light and the second light.

[0342] In an eighteenth aspect of the embodiment, in the seventeenth aspect, the illumination optical system includes a slit (22) arranged at a position approximately optically conjugate with the fundus, and having a first opening (22a) through which the first light passes and a second opening (22b) through which the second light passes. The photographing optical system includes an image sensor configured to receive, in each of two light-receiving regions spatially separated on the light-receiving surface, return light of the first light from an illumination region on the fundus corresponding to the first opening and return light of the second light from an illumination region on the fundus corresponding to the second opening.

[0343] According to this aspect, the first light and the second light can be simultaneously applied to acquire the first fundus image and the second fundus image, thereby shortening the imaging time and further reducing the burden on the subject.

[0344] A 19th aspect of the embodiment is the 17th aspect, and includes a first curved mirror (first elliptical concave mirror 11), a second curved mirror (second elliptical concave mirror 12), and an optical path separating member (60). The first curved mirror has a first focal point (F1) and a second focal point (F2). The second curved mirror has a third focal point (first focal point F3) arranged to substantially coincide with the second focal point and a fourth focal point (second focal point F4) at which the subject's eye can be positioned. The optical path separating member is arranged at the first focal point or a position substantially optically conjugate with the first focal point, and separates the optical path of the illumination optical system from the optical path of the imaging optical system. The illumination optical system is configured to illuminate the fundus with first light and second light via the first curved mirror and the second curved mirror. The imaging optical system is configured to receive return light of the first light and return light of the second light from the fundus via the first curved mirror and the second curved mirror.

[0345] According to this aspect, it is possible to easily obtain a wide-angle calculated image that depicts a contrast difference due to differences in imaging, without using a contrast agent or requiring a long scan time, and as a result, it is possible to easily obtain a wide-angle image that shows the subretinal structure, without imposing a burden on the subject.

[0346] A twentieth aspect of the embodiment is an ophthalmologic information processing method including a data acquisition step and a calculated image generation step. The data acquisition step acquires image data of two or more fundus images obtained by irradiating a fundus (Ef) of an eye (E) with two or more lights. The calculated image generation step generates a calculated image by performing image comparison processing on the two or more fundus images based on the data of the two or more fundus images.

[0347] This method makes it possible to easily obtain computed images that depict contrast differences due to differences in imaging without using contrast agents or requiring long scan times, thereby making it possible to easily obtain images that represent subretinal structures without imposing a burden on the subject.

[0348] In a 21st aspect of the embodiment, in the 20th aspect, the data acquiring step acquires first image data of a first fundus image obtained by irradiating the fundus with first light and second image data of a second fundus image obtained by irradiating the fundus with second light. The calculated image generating step performs image comparison processing on the first fundus image and the second fundus image based on the first image data and the second image data.

[0349] This method makes it possible to easily obtain a computed image that depicts the contrast difference resulting from the difference in imaging using two types of light, without using contrast agents or requiring long scan times.

[0350] In a 22nd aspect of the embodiment, in the 21st aspect, the first light is light having a first wavelength as a center wavelength, and the second light is light having a second wavelength as a center wavelength that is different from the first wavelength in at least one of the depth of penetration into the fundus and the light reaction characteristics.

[0351] According to this method, light having different depths of penetration and / or different light response characteristics is irradiated onto the fundus to obtain a calculated image, thereby making it possible to easily obtain an image representing the subretinal structure.

[0352] In a twenty-third aspect of the embodiment, in the twenty-second aspect, the first wavelength is a wavelength within the wavelength range of near-infrared light, and the second wavelength is a wavelength within the wavelength range of near-infrared light or a wavelength within the wavelength range of red light.

[0353] According to this method, the calculated image is an image projected pixel by pixel over a depth range between the depth reached by light in the red wavelength range and the depth reached by light in the infrared wavelength range, thereby making it possible to easily obtain a calculated image depicting the choroidal vascular region without using a contrast agent or requiring a long scanning time.

[0354] In a twenty-fourth aspect of the embodiment, in the twenty-second aspect, the first wavelength is a wavelength within a wavelength range of red light, and the second wavelength is a wavelength within a wavelength range of green light.

[0355] According to this method, it is possible to obtain a computed image in which the contrast of arterial and venous blood vessels is enhanced by focusing on the redox reaction of hemoglobin.

[0356] In a 25th aspect of the embodiment, in the 22nd aspect, the first light is light having a first wavelength in a wavelength range including an absorption peak wavelength of a predetermined site or tissue on the fundus, and the second light is light having a second wavelength different from the first wavelength.

[0357] According to this method, it is possible to obtain a calculated image that depicts the contrast difference resulting from the difference between the absorption peak of the first light and the absorption peak of the second light, without using a contrast agent or requiring a long scan time.

[0358] A 26th aspect of the embodiment is the method according to any one of the 20th to 25th aspects, further including a registration processing step of performing registration processing on two or more fundus images. The calculated image generating step generates a calculated image from the two or more fundus images obtained by the registration processing.

[0359] According to this method, it is possible to prevent degradation of the image quality of the calculated image that depicts a contrast difference caused by the difference in imaging using two types of light.

[0360] A twenty-seventh aspect of the embodiment is any of the twentieth to twenty-fifth aspects, further comprising a complementation processing step of complementing a defective portion of the calculated image.

[0361] According to this method, a calculated image in which the defective portion is complemented can be easily obtained.

[0362] In a 28th aspect of the embodiment, in the 27th aspect, the complementation processing step complements defective portions of the calculated image using a trained model obtained by performing machine learning in advance on the input calculated image to complement defective portions.

[0363] According to this method, a calculated image in which defects are complemented can be easily obtained using a trained model.

[0364] A twenty-ninth aspect of the embodiment is a program for causing a computer to execute each step of the ophthalmologic information processing method of any one of the twentieth to twenty-fifth aspects.

[0365] Such a program makes it possible to provide a program for easily obtaining a calculated image that depicts contrast differences resulting from differences in imaging, without using contrast agents or requiring long scan times.

[0366] <Others> The embodiment described above is merely one example for carrying out the present invention. Those who wish to carry out the present invention may make any modifications, omissions, additions, etc. within the scope of the gist of the present invention.

[0367] DESCRIPTION OF SYMBOLS 1, 300 Ophthalmic apparatus 20 Illumination optical system 30 Light source unit 40 Optical scanner 50 Imaging optical system 60 Optical path separating member 70 Imaging device 100, 320, 420 Control unit 110 Main control unit 200 Image forming unit 210 Data processing unit 211 Registration processing unit 212 Calculated image generating unit 220 Analysis unit 221 Complement processing unit 222 Blood vessel condition specifying unit 223 Symmetry determining unit 310 Optical system 330, 430 Communication unit 400 Ophthalmic information processing device 410 Ophthalmic information processing unit E Eye to be inspected Ef Fundus λ1 First wavelength λ2 Second wavelength

Claims

1. An ophthalmologic information processing device comprising: a data acquisition unit that acquires image data of two or more fundus images obtained by irradiating the fundus of a subject's eye with two or more lights; and a calculated image generation unit that generates a calculated image by performing image comparison processing on the two or more fundus images based on the image data of the two or more fundus images.

2. The ophthalmologic information processing device of claim 1, characterized in that the data acquisition unit acquires first image data of a first fundus image obtained by irradiating the fundus with first light and second image data of a second fundus image obtained by irradiating the fundus with second light, and the calculated image generation unit performs the image comparison processing on the first fundus image and the second fundus image based on the first image data and the second image data.

3. The ophthalmologic information processing device according to claim 2, characterized in that the first light is light having a first wavelength as its center wavelength, and the second light is light having a second wavelength as its center wavelength, which is different from the first wavelength in at least one of the depth of penetration into the fundus and the light reaction characteristics.

4. The ophthalmologic information processing device according to claim 3, characterized in that the first wavelength is a wavelength within the wavelength range of near-infrared light, and the second wavelength is a wavelength within the wavelength range of near-infrared light or a wavelength within the wavelength range of red light.

5. The ophthalmologic information processing device according to claim 3, wherein the first wavelength is a wavelength within a wavelength range of red light, and the second wavelength is a wavelength within a wavelength range of green light.

6. The ophthalmologic information processing device according to claim 2, characterized in that the first light is light having a first wavelength in a wavelength range including an absorption peak wavelength of a specified site or specified tissue in the fundus as its center wavelength, and the second light is light having a second wavelength different from the first wavelength as its center wavelength.

7. An ophthalmologic information processing device according to any one of claims 1 to 6, characterized in that it includes a registration processing unit that performs registration processing on the two or more fundus images, and the calculated image generation unit generates the calculated image from the two or more fundus images obtained by the registration processing.

8. The ophthalmologic information processing device according to any one of claims 1 to 6, characterized in that it includes a complementation processing unit that complements defective portions of the calculated image.

9. The ophthalmologic information processing device according to claim 8, characterized in that the completion processing unit complements defective portions of the input calculated image using a trained model obtained by performing machine learning in advance to complement defective portions of the input calculated image.

10. An ophthalmologic device comprising: an illumination optical system that illuminates the two or more lights onto the fundus; an imaging optical system that receives two or more return lights of the two or more lights from the fundus; a control unit that controls the illumination optical system to control the illumination timing of the two or more lights, and controls the imaging optical system to control the reception timing of the two or more return lights in synchronization with the illumination timing; and an ophthalmologic information processing device according to any one of claims 1 to 6 that acquires the image data of the two or more fundus images formed based on the two or more return lights.

11. The ophthalmologic device of claim 10, wherein the irradiation optical system irradiates the fundus with first light and second light, the photographing optical system receives the return light of the first light and the return light of the second light, the control unit controls the irradiation timing of the first light and the second light by controlling the irradiation optical system, and controls the reception timing of the return light of the first light and the return light of the second light in synchronization with the irradiation timing by controlling the photographing optical system, and the ophthalmologic information processing device acquires first image data of a first fundus image formed based on the return light of the first light and second image data of a second fundus image formed based on the return light of the second light.

12. The ophthalmologic apparatus according to claim 11, wherein the control unit controls the irradiation optical system so as to repeatedly irradiate the first light and the second light onto the fundus.

13. The ophthalmologic apparatus according to claim 11, wherein the control unit controls the irradiation optical system so as to simultaneously irradiate the first light and the second light onto the fundus.

14. The ophthalmic device according to claim 11, characterized in that the irradiation optical system includes a light source and one or more wavelength-selective filters that can be selectively positioned on the optical path of light from the light source, and the control unit selectively inserts or removes the one or more wavelength-selective filters on the optical path.

15. The ophthalmic device according to claim 11, wherein the photographing optical system includes a first image sensor that receives the return light of the first light, and a second image sensor that receives the return light of the second light.

16. The ophthalmic device according to claim 11, characterized in that the photographing optical system includes an image sensor in which a detection element has a wavelength sensitivity characteristic in which the detection sensitivity at a first wavelength, which is the central wavelength of the first light, is higher than the detection sensitivity at a second wavelength, which is the central wavelength of the second light, and a detection element has a wavelength sensitivity characteristic in which the detection sensitivity at the second wavelength is higher than the detection sensitivity at the first wavelength, are arranged.

17. The ophthalmic device of claim 11, wherein the irradiation optical system is configured to irradiate the fundus with slit-shaped first light and slit-shaped second light, and the photographing optical system is configured to capture the results of receiving the return light of the first light in a light-receiving area on the fundus corresponding to the irradiation range of the first light, and to capture the results of receiving the return light of the second light in a light-receiving area on the fundus corresponding to the irradiation range of the second light.

18. The ophthalmic device of claim 17, wherein the illumination optical system includes a slit arranged at a position approximately optically conjugate with the fundus, and in which a first opening through which the first light passes and a second opening through which the second light passes are formed, and the photographing optical system includes an image sensor configured to receive, in each of two spatially separated light-receiving areas on the light-receiving surface, return light of the first light from an illumination area corresponding to the first opening on the fundus and return light of the second light from an illumination area corresponding to the second opening on the fundus.

19. An ophthalmic device according to claim 17, comprising: a first curved mirror having a first focus and a second focus; a second curved mirror having a third focus positioned to approximately coincide with the second focus and a fourth focus at which the subject's eye can be positioned; and an optical path separating member positioned at the first focus or at a position approximately optically conjugate with the first focus, separating the optical path of the illumination optical system from the optical path of the photographing optical system, wherein the illumination optical system is configured to illuminate the first light and the second light onto the fundus via the first curved mirror and the second curved mirror, and the photographing optical system is configured to receive return light of the first light and return light of the second light from the fundus via the first curved mirror and the second curved mirror.

20. An ophthalmologic information processing method comprising: a data acquisition step of acquiring image data of two or more fundus images obtained by irradiating the fundus of the subject's eye with two or more lights; and a computed image generation step of generating a computed image by performing image comparison processing on the two or more fundus images based on the data of the two or more fundus images.

21. The ophthalmologic information processing method of claim 20, characterized in that the data acquisition step acquires first image data of a first fundus image obtained by irradiating the fundus with first light and second image data of a second fundus image obtained by irradiating the fundus with second light, and the calculated image generation step performs the image comparison processing on the first fundus image and the second fundus image based on the first image data and the second image data.

22. The ophthalmologic information processing method according to claim 21, characterized in that the first light is light having a first wavelength as its center wavelength, and the second light is light having a second wavelength as its center wavelength, which is different from the first wavelength in at least one of the depth of penetration into the fundus and the light reaction characteristics.

23. The ophthalmologic information processing method according to claim 22, characterized in that the first wavelength is a wavelength within the wavelength range of near-infrared light, and the second wavelength is a wavelength within the wavelength range of near-infrared light or a wavelength within the wavelength range of red light.

24. The ophthalmologic information processing method according to claim 22, wherein the first wavelength is a wavelength within a wavelength range of red light, and the second wavelength is a wavelength within a wavelength range of green light.

25. The ophthalmologic information processing method of claim 22, wherein the first light is light having a first wavelength as a center wavelength in a wavelength range that includes the absorption peak wavelength of a specified site or specified tissue in the fundus, and the second light is light having a second wavelength as a center wavelength that is different from the first wavelength.

26. An ophthalmologic information processing method according to any one of claims 20 to 25, characterized in that it includes a registration processing step for performing registration processing on the two or more fundus images, and the calculated image generation step generates the calculated image from the two or more fundus images obtained by the registration processing.

27. An ophthalmologic information processing method according to any one of claims 20 to 25, characterized in that it includes a complementation processing step for compensating for defects in the calculated image.

28. The ophthalmologic information processing method according to claim 27, characterized in that the interpolation processing step interpolates defective portions of the input calculated image using a trained model obtained by performing machine learning in advance to interpolate defective portions of the input calculated image.

29. A program causing a computer to execute each step of the ophthalmologic information processing method according to any one of claims 20 to 25.

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