Eye model and ophthalmic device

Abstract

To provide a schematic eye suitable as a phantom for optical coherence tomography angiography.SOLUTION: A schematic eye according to an embodiment is a phantom used to evaluate an optical coherence tomography angiography function of an ophthalmologic apparatus. The schematic eye includes a liquid storage part. In the liquid storage part, liquid with fine particles making the Brownian motion floating therein is encapsulated and stored.SELECTED DRAWING: Figure 6A

Description

[Technical Field]

[0001] The present invention relates to an eye model and an ophthalmic apparatus. [Background technology]

[0002] Various imaging modalities are used in ophthalmology, one of the most well-known being optical coherence tomography (OCT), which is used for both structural and functional imaging.

[0003] For example, OCT angiography (OCTA) is a functional imaging modality for depicting blood flow, and is used to obtain images of retinal and choroidal blood vessels (see, for example, Patent Document 1). OCTA is a technology that focuses on the fact that signals from the fundus tissue (structure) do not change over time, while signals from the blood flow inside the blood vessels change over time, and constructs a blood vessel image by emphasizing areas where such temporal changes exist (blood flow signals). OCTA is also called OCT motion contrast imaging. Images constructed by OCTA are called angiographic images, angiograms, motion contrast images, etc.

[0004] Ophthalmic devices capable of performing OCTA are extremely precise optical instruments, and in order to fully utilize their performance, adjustments and calibrations based on rigorous evaluations are required. There are various methods for evaluating ophthalmic devices, but the most widely used method is to use a model eye as a phantom (see, for example, Patent Documents 2 and 3 and Non-Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2015-515894 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-110575 [Patent Document 3] Japanese Patent Application Publication No. 2019-76181 [Non-patent literature]

[0006] [Non-Patent Document 1] Jigesh Baxi and 7 others, "Retina-simulating phantom for optical coherence tomography," Journal of Biomedical Optics, February 2014, Vol. 19, No. 2, 021106-1~021106-8 Summary of the Invention [Problem to be solved by the invention]

[0007] However, although conventional eye models can be used as phantoms for OCT structural imaging, they cannot be used as phantoms for OCTA.

[0008] It is also possible to construct a phantom system that mimics blood flow by flowing a liquid, but this entails problems such as the need for a device to generate the liquid flow, the complexity of the model eye and system structure, and the size of the system.

[0009] One object of the present invention is to provide a model eye suitable as a phantom for OCTA and an ophthalmologic apparatus equipped with the same. [Means for solving the problem]

[0010] Some exemplary embodiments include an eye model for use in the field of ophthalmology, which includes a liquid container containing a liquid in which particles are suspended.

[0011] In some exemplary embodiments, the eye model includes a plurality of the liquid containment units.

[0012] In some exemplary embodiments, the plurality of liquid storage sections store liquids of different viscosities.

[0013] In some exemplary embodiments, the plurality of liquid storage sections store the liquid in which the particles of different sizes are suspended.

[0014] In some exemplary embodiments, at least one of the plurality of liquid containments is disposed at an angle relative to the axial direction.

[0015] In some exemplary embodiments, at least two of the plurality of liquid containments are disposed at different tilt angles relative to the axial direction.

[0016] In some exemplary embodiments, the liquid containment section is disposed at an angle relative to the axial direction.

[0017] The eye model of some exemplary embodiments further includes a laminate of multiple layers.

[0018] In some exemplary embodiments, the liquid containment section is disposed within any of the layers.

[0019] In some exemplary embodiments, the liquid containment section is provided in each of at least two of the plurality of layers.

[0020] In some exemplary embodiments, the liquid containment section is disposed across at least two of the plurality of layers.

[0021] In some exemplary embodiments, a portion of the liquid containment section is exposed from the stack.

[0022] In some exemplary embodiments, the liquid containment portion is reorientable.

[0023] The eye model in some exemplary embodiments further includes a first temperature control unit for maintaining a constant temperature of the liquid.

[0024] In some exemplary embodiments, the eye model further includes a second temperature control unit for changing the temperature of the liquid.

[0025] In some exemplary embodiments, the liquid containment portion includes a tubular body in which the liquid is enclosed.

[0026] Some exemplary embodiments are ophthalmic devices including a data acquisition unit for optically acquiring data of an eye and a model eye for evaluation of the data acquisition unit, the model eye including a liquid storage unit that stores a liquid in which fine particles are suspended.

[0027] In some exemplary embodiments, the ophthalmologic apparatus further includes an evaluation unit that generates evaluation information based on the data acquired from the eye model by the data acquisition unit.

[0028] In some exemplary aspects, the data acquisition unit includes an optical system, and the ophthalmic device further includes an alignment system that aligns the optical system with a model eye installed at a predetermined position, and the evaluation unit generates the evaluation information based on data acquired from the model eye by the data acquisition unit after the alignment.

[0029] In some exemplary embodiments, the data acquisition unit acquires data from a specific portion of the eye model at least twice, and the evaluation unit generates the evaluation information based on two or more pieces of data acquired from the specific portion by the data acquisition unit. [Effects of the Invention]

[0030] According to some exemplary embodiments, it is possible to provide a model eye suitable as a phantom for OCTA or an ophthalmic apparatus including the model eye. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 2] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 3A] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 3B] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 4A] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 4B] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 5] 1 is a schematic diagram illustrating a configuration of a model eye according to an exemplary embodiment. [Figure 6A] 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. [Figure 6B] 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. [Figure 7] 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. [Figure 8] 1A and 1B are schematic diagrams illustrating a method and configuration for creating a liquid containment section in an eye model according to an exemplary embodiment. [Figure 9] 1 is a schematic diagram illustrating the arrangement of a liquid storage portion in an eye model according to an exemplary embodiment. [Figure 10] 1 is a schematic diagram illustrating the arrangement of a liquid storage portion in an eye model according to an exemplary embodiment. [Figure 11] 1 is a schematic diagram illustrating the arrangement of a liquid storage portion in an eye model according to an exemplary embodiment. [Figure 12] 1 is a schematic diagram illustrating the arrangement of a liquid storage portion in an eye model according to an exemplary embodiment. [Figure 13A] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 13B] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 14] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 15] 10 is a flowchart illustrating operations that can be performed by an ophthalmic apparatus according to an exemplary embodiment. [Figure 16] 1 is an OCTA image of an eye model according to an exemplary embodiment. [Figure 17] 1 is a flowchart illustrating a method for manufacturing a laminate according to an exemplary embodiment. [Figure 18A] 1 is a schematic diagram illustrating a configuration of a model eye according to an exemplary embodiment. [Figure 18B] 1 is a schematic diagram illustrating a model eye according to an exemplary embodiment. [Figure 18C] 1 is a schematic diagram illustrating a model eye according to an exemplary embodiment. [Figure 19] 1 is a schematic diagram illustrating a model eye according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0032] Several exemplary aspects of the eye model and ophthalmic device according to the embodiment will be described. The ophthalmic device according to the exemplary aspects includes the eye model according to the exemplary aspect. Furthermore, the performance of the ophthalmic device can be evaluated using the eye model according to the exemplary aspect.

[0033] The ophthalmic apparatus according to the exemplary embodiments described below is a multifunction device that combines an OCT apparatus capable of performing OCTA with a fundus camera, but the ophthalmic apparatus according to the exemplary embodiments is not limited to this and may be any ophthalmic apparatus having an OCTA function. The ophthalmic apparatus according to some exemplary embodiments has at least one of an alignment function and a performance evaluation function. The ophthalmic apparatus according to some exemplary embodiments includes an eye model for performance evaluation. On the other hand, the ophthalmic apparatus according to some exemplary embodiments does not include an eye model for performance evaluation.

[0034] The OCT device included in the exemplary ophthalmic device described below employs spectral domain OCT, but the type of OCT applicable to the exemplary ophthalmic device is not limited to spectral domain OCT and may be, for example, swept-source OCT.

[0035] Spectral domain OCT is a technique in which light from a low-coherence light source is split into measurement light and reference light, and the return light of the measurement light from the test object is superimposed on the reference light to generate interference light. The spectral distribution of this interference light is detected using a spectroscope, and the detected spectral distribution is subjected to Fourier transform or the like to form an image.

[0036] In contrast, swept-source OCT is a technique in which light from a tunable light source is split into measurement light and reference light, and the return light of the measurement light from the test object is superimposed on the reference light to generate interference light. This interference light is detected by a photodetector such as a balanced photodiode, and the detection data collected in response to the wavelength sweep and scanning of the measurement light is subjected to Fourier transform, etc. to form an image.

[0037] In this way, spectral domain OCT is an OCT method that acquires the spectral distribution in a spatially divided manner, while swept-source OCT is an OCT method that acquires the spectral distribution in a time-divided manner. Note that other OCT methods, such as time-domain OCT, may also be used.

[0038] In this specification, unless otherwise specified, no distinction is made between "image data" and "image," which is visual information based on the image data. Furthermore, unless otherwise specified, no distinction is made between a region or tissue of the subject's eye and a corresponding portion of the eye model. Furthermore, unless otherwise specified, no distinction is made between a region or tissue of the subject's eye and its image, and no distinction is made between a portion of the eye model and its image.

[0039] <Configuration of ophthalmic device> An exemplary embodiment of an ophthalmic apparatus is shown in Fig. 1. The ophthalmic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic and control unit 200. The fundus camera unit 2 is provided with an optical system and mechanism for acquiring a front image of the subject's eye E, and an optical system and mechanism for performing OCT. The OCT unit 100 is provided with an optical system and mechanism for performing OCT. The arithmetic and control unit 200 includes one or more processors configured to perform various processes (calculation, control, etc.). Furthermore, the ophthalmic apparatus 1 is provided with two anterior eye cameras 300 for photographing the anterior eye from two different directions.

[0040] The fundus camera unit 2 is provided with a chin rest and a forehead rest for holding the face of the subject. The chin rest and the forehead rest correspond to the face holder 450 shown in Figures 4A and 4B. A drive mechanism and an arithmetic and control circuit are housed in the base 310. An optical system is housed in a housing 320 provided on the base 310. An objective lens 22 is housed in a lens housing portion 330 provided to protrude from the front of the housing 320.

[0041] Furthermore, the ophthalmic apparatus 1 includes a lens unit for switching the region to which OCT is applied. Specifically, the ophthalmic apparatus 1 includes an anterior segment OCT attachment 400 for applying OCT to the anterior segment of the eye. The anterior segment OCT attachment 400 may be configured similarly to the optical unit disclosed in, for example, Japanese Patent Application Laid-Open No. 2015-160103.

[0042] 1, the anterior segment OCT attachment 400 can be placed between the objective lens 22 and the subject's eye E. When the anterior segment OCT attachment 400 is placed in the optical path, the ophthalmic apparatus 1 can apply an OCT scan to the anterior segment. On the other hand, when the anterior segment OCT attachment 400 is retracted from the optical path, the ophthalmic apparatus 1 can apply an OCT scan to the posterior segment. The anterior segment OCT attachment 400 can be moved manually or automatically.

[0043] In some embodiments, an OCT scan may be performed on the posterior segment of the eye when the attachment is positioned in the optical path, and on the anterior segment when the attachment is retracted from the optical path. Furthermore, the measurement site switched by the attachment is not limited to the posterior segment and the anterior segment, but may be any site on the eye. The configuration for switching the site to which the OCT scan is performed is not limited to such an attachment; for example, a configuration including a lens that can be moved along the optical path or a configuration including a lens that can be inserted into or removed from the optical path may also be used.

[0044] At least a portion of the functionality of the elements disclosed herein is implemented using circuitry or processing circuitry. The circuitry or processing circuitry may be a general-purpose processor, a special-purpose processor, an integrated circuit, a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), a field programmable gate array (FPGA)), or a combination of these devices configured and / or programmed to perform at least a portion of the disclosed functionality. The term "circuitry," "unit," "means," or the like refers to hardware that performs at least a portion of the disclosed functions or that is programmed to perform at least a portion of the disclosed functions. The hardware may be the hardware disclosed herein or may be known hardware that is programmed and / or configured to perform at least a portion of the described functions. In the case of a processor, where the hardware can be considered a type of circuitry, the term "circuitry," "unit," "means," or the like refers to a combination of hardware and software, where the software is used to configure the hardware and / or the processor.

[0045] Fundus Camera Unit 2 The fundus camera unit 2 is provided with an optical system for photographing the fundus Ef (and the anterior segment) of the subject's eye E. The acquired digital image of the fundus Ef (called a fundus image, fundus photograph, etc.) is generally a front image such as an observed image or a photographed image. The observed image is obtained by capturing a moving image using near-infrared light. The photographed image is a still image captured using flash light in the visible range.

[0046] The fundus camera unit 2 includes an illumination optical system 10 and an imaging optical system 30. The illumination optical system 10 irradiates illumination light onto the subject's eye E. The imaging optical system 30 detects return light of the illumination light irradiated onto the subject's eye E. Measurement light from the OCT unit 100 is guided to the subject's eye E through an optical path within the fundus camera unit 2. Return light of the measurement light projected onto the subject's eye E (e.g., fundus Ef) is guided to the OCT unit 100 through the same optical path within the fundus camera unit 2.

[0047] Light (observation illumination light) output from an observation light source 11 of an illumination optical system 10 is reflected by a concave mirror 12, passes through a condenser lens 13, and is transmitted through a visible light cut filter 14 to become near-infrared light. The observation illumination light is then focused near a photographing light source 15, reflected by a mirror 16, and directed to a perforated mirror 21 via a relay lens system 17, a relay lens 18, an aperture 19, and a relay lens system 20. The observation illumination light is then reflected from the peripheral portion of the perforated mirror 21 (the area surrounding the hole), passes through a dichroic mirror 46, and is refracted by an objective lens 22 to illuminate the subject's eye E (fundus oculi Ef). Return light of the observation illumination light from the subject's eye E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through a hole formed in the central area of ​​the perforated mirror 21, passes through a dichroic mirror 55, passes through a photographing focusing lens 31, and is reflected by a mirror 32. Furthermore, this returned light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged by the imaging lens 34 on the light receiving surface of the image sensor 35. The image sensor 35 detects the returned light at a predetermined frame rate. The focus of the photographing optical system 30 can be adjusted to match the fundus Ef or its vicinity, and can also be adjusted to match the anterior segment or its vicinity.

[0048] Light (photography illumination light) output from the photography light source 15 is irradiated onto the fundus oculi Ef along the same path as the observation illumination light. Return light of the photography illumination light from the subject's eye E is guided to the dichroic mirror 33 along the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by a mirror 36, and is imaged by an imaging lens 37 on the light-receiving surface of an image sensor 38.

[0049] The liquid crystal display (LCD) 39 displays a fixation target (fixation target image). A portion of the light beam output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, passes through the photographing focusing lens 31 and the dichroic mirror 55, and passes through the hole in the aperture mirror 21. The light beam that passes through the hole in the aperture mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef. The fixation target is typically used to guide and fixate the gaze of the subject's eye E. The direction to which the gaze of the subject's eye E is guided (and fixed), i.e., the direction in which the subject's eye E is encouraged to fixate, is called the fixation position.

[0050] The fixation position can be changed by changing the display position of the fixation target image on the screen of the LCD 39. Examples of fixation positions include a fixation position for acquiring an image centered on the macula, a fixation position for acquiring an image centered on the optic disc, a fixation position for acquiring an image centered on a position between the macula and the optic disc (center of the fundus), and a fixation position for acquiring an image of a region far away from the macula (periphery of the fundus).

[0051] A graphical user interface (GUI) or the like can be provided for specifying at least one of these typical fixation positions. A GUI or the like can also be provided for manually moving the fixation position (display position of the fixation target). It is also possible to apply a configuration for automatically setting the fixation position.

[0052] The configuration for presenting a fixation target with a changeable fixation position to the subject's eye E is not limited to a display device such as an LCD. For example, a device (fixation matrix) in which a plurality of light-emitting elements (such as light-emitting diodes) are arranged in a matrix can be used instead of a display device. In this case, the fixation position of the subject's eye E based on the fixation target can be changed by selectively turning on the plurality of light-emitting elements. As another example, a fixation target with a changeable fixation position can be generated by a device having one or more movable light-emitting elements.

[0053] The alignment optical system 50 generates an alignment index used to align the optical system with the subject's eye E. Alignment light output from a light-emitting diode (LED) 51 passes through an aperture 52, an aperture 53, and a relay lens 54, is reflected by a dichroic mirror 55, passes through the hole in the aperture mirror 21, transmits through the dichroic mirror 46, and is projected onto the subject's eye E via the objective lens 22. The return light of the alignment light from the subject's eye E is guided to the image sensor 35 via the same path as the return light of the observation illumination light. Manual alignment or automatic alignment can be performed based on the received light image (alignment index image).

[0054] It should be noted that the alignment method applicable to the exemplary embodiment is not limited to one that uses such an alignment indicator, and may be any known method, such as a method that uses an anterior eye camera 300, a method that uses a corneal reflection image (Purkinje image) formed by projecting a light beam onto the cornea from the front, or a method that uses an optical lever that projects a light beam onto the cornea from an oblique angle and detects the corneal reflection light in the opposite direction.

[0055] The focusing optical system 60 generates a split index used for focus adjustment of the subject's eye E. The focusing optical system 60 moves along the optical path (illumination optical path) of the illumination optical system 10 in conjunction with movement of the photographing focusing lens 31 along the optical path (photographing optical path) of the photographing optical system 30. The reflecting rod 67 is inserted into and removed from the illumination optical path. When performing focus adjustment, the reflecting surface of the reflecting rod 67 is tilted and positioned in the illumination optical path. Focusing light output from the LED 61 passes through the relay lens 62, is split into two beams by the split index plate 63, passes through the two-hole diaphragm 64, is reflected by the mirror 65, and is first imaged and reflected on the reflecting surface of the reflecting rod 67 by the condenser lens 66. The focusing light then passes through the relay lens 20, is reflected by the aperture mirror 21, passes through the dichroic mirror 46, and is projected onto the subject's eye E via the objective lens 22. The return light (fundus reflected light, etc.) of the focusing light from the subject's eye E is guided to the image sensor 35 via the same path as the return light of the alignment light. Manual focusing or autofocusing can be performed based on the received light image (split target image).

[0056] Diopter correction lenses 70 and 71 can be selectively inserted into the photographing optical path between the aperture mirror 21 and the dichroic mirror 55. The diopter correction lens 70 is a plus lens (convex lens) for correcting severe hyperopia. The diopter correction lens 71 is a minus lens (concave lens) for correcting severe myopia.

[0057] The dichroic mirror 46 combines the optical path for fundus imaging and the optical path for OCT (measurement arm). The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for fundus imaging. The measurement arm is provided with, in order from the OCT unit 100 side, a collimator lens unit 40, a retroreflector 41, a dispersion compensation member 42, an OCT focusing lens 43, an optical scanner 44, and a relay lens 45.

[0058] The retroreflector 41 is movable along the optical path of the measurement light LS incident thereon, thereby changing the length of the measurement arm, which is used for, for example, correcting the optical path length according to the axial length of the eye, adjusting the interference state, and so on.

[0059] The dispersion compensation member 42, together with a dispersion compensation member 113 (described later) disposed in the reference arm, acts to match the dispersion characteristics of the measurement light LS with the dispersion characteristics of the reference light LR.

[0060] The OCT focusing lens 43 is moved along the measurement arm to adjust the focus of the measurement arm. The movement of the imaging focusing lens 31, the movement of the focus optical system 60, and the movement of the OCT focusing lens 43 can be controlled in a coordinated manner.

[0061] The optical scanner 44 is disposed substantially at a position optically conjugate with the pupil of the subject's eye E. The optical scanner 44 deflects the measurement light LS guided by the measurement arm. The optical scanner 44 is, for example, a galvanometer scanner capable of two-dimensional scanning. Typically, the optical scanner 44 includes a one-dimensional scanner (x-scanner) for deflecting the measurement light in ±x directions and a one-dimensional scanner (y-scanner) for deflecting the measurement light in ±y directions. In this case, for example, either one of these one-dimensional scanners is disposed at a position optically conjugate with the pupil, or a position optically conjugate with the pupil is disposed between these one-dimensional scanners.

[0062] <OCT Unit 100> The exemplary OCT unit 100 shown in FIG. 2 is provided with an optical system for performing spectral-domain OCT. This optical system includes an interference optical system. This interference optical system splits light from a low-coherence light source (broadband light source) into measurement light and reference light, and generates interference light by superimposing the return light of the measurement light projected onto the subject's eye E and the reference light that has passed through the reference light path. The spectral distribution of the interference light generated by the interference optical system is detected by a spectrometer. Data (detection signals) obtained by detecting the spectral distribution of the interference light are sent to the arithmetic and control unit 200.

[0063] The light source unit 101 outputs broadband low-coherence light L0. The low-coherence light L0 includes, for example, a wavelength band in the near-infrared region (approximately 800 to 900 nanometers) and has a temporal coherence length of approximately several tens of micrometers. Note that the low-coherence light L0 may be near-infrared light having a center wavelength of approximately 1040 to 1060 nanometers, for example, a wavelength band that is not visible to the human eye. The light source unit 101 includes a light output device such as a superluminescent diode (SLD), an LED, or a semiconductor optical amplifier (SOA).

[0064] When swept-source OCT is employed, the light source unit includes, for example, a near-infrared wavelength-tunable laser that changes the wavelength of emitted light at high speed.

[0065] Low-coherence light L0 output from light source unit 101 is guided by optical fiber 102 to polarization controller 103, where its polarization state is adjusted. Light L0 with its polarization state adjusted is guided by optical fiber 104 to fiber coupler 105, where it is split into measurement light LS and reference light LR. The optical path that guides measurement light LS is called a measurement arm, etc., and the optical path that guides reference light LR is called a reference arm, etc.

[0066] The reference light LR generated by the fiber coupler 105 is guided by an optical fiber 110 to a collimator 111, where it is converted into a parallel beam, and then guided to a retroreflector 114 via an optical path length correction element 112 and a dispersion compensation element 113. The optical path length correction element 112 acts to match the optical path length of the reference light LR with that of the measurement light LS. The dispersion compensation element 113, together with a dispersion compensation element 42 arranged in the measurement arm, acts to match the dispersion characteristics between the reference light LR and the measurement light LS. The retroreflector 114 is movable along the optical path of the reference light LR incident thereon, thereby changing the length of the reference arm. Changing the reference arm length is used, for example, to correct the optical path length according to the axial length or to adjust the interference state.

[0067] The reference light LR that has passed through the retroreflector 114 passes through the dispersion compensation member 113 and the optical path length correction member 112, is converted from a parallel beam into a convergent beam by the collimator 116, and enters an optical fiber 117. The reference light LR that has entered the optical fiber 117 is guided to a polarization controller 118 where its polarization state is adjusted, is guided through an optical fiber 119 to an attenuator 120 where its light amount is adjusted, and is guided through an optical fiber 121 to a fiber coupler 122.

[0068] On the other hand, the measurement light LS generated by the fiber coupler 105 is guided through the optical fiber 127 to the collimator lens unit 40, where it is converted into a parallel beam, passes through the retroreflector 41, the dispersion compensation member 42, the OCT focusing lens 43, the optical scanner 44, and the relay lens 45, is reflected by the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the subject's eye E. The measurement light LS is scattered and reflected at various depth positions in the subject's eye E. Return light of the measurement light LS from the subject's eye E travels in the opposite direction through the measurement arm, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

[0069] The fiber coupler 122 superimposes the measurement light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121 to generate interference light LC.

[0070] The interference light LC generated by the fiber coupler 122 is guided to the spectrometer 130 through the optical fiber 129. The spectrometer 130 converts the incident interference light LC into a parallel beam using a collimator lens, resolves the parallel beam of interference light LC into spectral components using a diffraction grating, and projects the spectral components resolved by the diffraction grating onto an image sensor using a lens 114. This image sensor is, for example, a line sensor, and detects the multiple spectral components of the interference light LC to generate an electrical signal (detection signal). The generated detection signal is sent to the arithmetic and control unit 200.

[0071] When swept-source OCT is employed, interference light generated by superimposing measurement light and reference light is split at a predetermined splitting ratio (e.g., 1:1) to generate a pair of interference light beams, which are then guided to a photodetector. The photodetector includes, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that respectively detect the pair of interference light beams and output the difference between the pair of detection signals obtained by these. The photodetector sends this output (detection signal such as a differential signal) to a data acquisition system (DAQ). A clock is supplied to the data acquisition system from the light source unit. The clock is generated in the light source unit in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength-tunable light source. For example, the light source unit splits light of each output wavelength to generate two split light beams, optically delays one of the split light beams, combines the split light beams, detects the resulting combined light, and generates a clock based on the detection signal. The data acquisition system samples the detection signal (differential signal) input from the photodetector based on the clock. The data obtained by this sampling is used for processing such as image construction.

[0072] The ophthalmic apparatus 1 shown in FIGS. 1 and 2 is provided with both an element for changing the measurement arm length (e.g., retroreflector 41) and an element for changing the reference arm length (e.g., retroreflector 114 or reference mirror), but in some exemplary embodiments, only one of these elements is provided. The coherence gate position is changed by changing the measurement arm length and the reference arm length relatively (i.e., by changing the optical path length difference between the measurement arm and the reference arm). The element for changing the optical path length difference is not limited to the elements disclosed in this embodiment and may be any element (optical member, mechanism, etc.).

[0073] <Arithmetic and control unit 200> The arithmetic and control unit 200 controls each part of the ophthalmologic apparatus 1. The arithmetic and control unit 200 also performs various calculations. For example, the arithmetic and control unit 200 forms a reflection intensity profile for each A-line by performing signal processing such as Fourier transform on the spectral distribution acquired by the spectroscope 130. Furthermore, the arithmetic and control unit 200 forms image data by imaging the reflection intensity profile for each A-line. The calculation processing for this is similar to that of conventional spectral domain OCT.

[0074] The arithmetic control unit 200 includes, for example, a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, a communication interface, etc. Various computer programs are stored in the storage device such as the hard disk drive. The arithmetic control unit 200 may also include an operation device, an input device, a display device, etc.

[0075] As shown in FIG. 3A , the user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes, for example, the display device 3. The operation unit 242 includes various operation devices and input devices. The user interface 240 may include a device that integrates a display function and an operation function, such as a touch panel. An ophthalmic apparatus according to some exemplary embodiments may not include at least a part of the user interface. For example, the display device and / or the operation device may be peripheral devices of the ophthalmic apparatus.

[0076] <Anterior Eye Camera 300> The anterior eye camera 300 captures images of the anterior eye of the subject's eye E from two or more different directions. The anterior eye camera 300 includes an imaging element such as a CCD image sensor or a CMOS image sensor. In this embodiment, two anterior eye cameras 300 are provided on the front surface (the surface facing the subject) of the fundus camera unit 2 (see the anterior eye cameras 300A and 300B shown in FIG. 4A). As shown in FIGS. 1 and 4A, the anterior eye cameras 300A and 300B are provided at positions off the optical path passing through the objective lens 22. In the present disclosure, one of the anterior eye cameras 300A and 300B may be denoted by the reference numeral 300, or both may be collectively denoted by the reference numeral 300. Furthermore, anterior eye cameras that can be used instead of the anterior eye cameras 300A and 300B may be denoted by the reference numeral 300.

[0077] In this embodiment, two anterior eye cameras 300A and 300B are provided, but the number of anterior eye cameras 300 may be any number equal to or greater than one. Considering the calculation process described below, a configuration capable of photographing the anterior eye from two different directions is sufficient (but is not limited to this). Alternatively, a movable anterior eye camera 300 may be provided so that images of the anterior eye are photographed sequentially from two or more different positions.

[0078] In this embodiment, two anterior eye cameras 300 are provided separately from the illumination optical system 10 and the photographing optical system 30, but the anterior eye can be photographed using the photographing optical system 30, for example. That is, one of the two or more anterior eye cameras 300 may be the photographing optical system 30. The anterior eye camera 300 according to this embodiment may be capable of photographing the anterior eye from two (or more) mutually different directions.

[0079] A configuration for illuminating the anterior segment may be provided. This anterior segment illumination means may include, for example, one or more light sources. Typically, at least one light source (e.g., an infrared light source) may be provided near each of the two or more anterior segment cameras 300.

[0080] Typically, the anterior eye segment is photographed from two or more different directions substantially simultaneously. The term "substantially simultaneously" refers to the case where the timing of photographing the anterior eye segment from two or more different directions is simultaneous, and also to the case where there is a timing difference sufficient to ignore eye movement. Such substantially simultaneous photographing allows the anterior eye segment to be photographed from two or more different directions when the subject's eye E is in substantially the same position and orientation.

[0081] The anterior eye images captured from two or more different directions may be either video or still images. In the case of video, the above-described substantially simultaneous anterior eye images can be achieved by, for example, controlling the timing at which the two or more anterior eye cameras 300 start capturing images to coincide, or by controlling the frame rate and the timing at which each frame is acquired. On the other hand, in the case of still image capture, the anterior eye images can be achieved substantially simultaneously by, for example, controlling the timing at which the two or more anterior eye cameras 300 capture images to coincide.

[0082] When photographing a model eye as described later, it is not necessary to perform such substantially simultaneous photographing.

[0083] <Control System> 3A and 3B show an example of the configuration of the control system (processing system) of the ophthalmologic apparatus 1. The control unit 210, the image forming unit 220, and the data processing unit 230 are provided in the arithmetic control unit 200, for example.

[0084] <Control unit 210> The control unit 210 includes a processor and controls each unit of the ophthalmologic apparatus 1. The control unit 210 includes a main control unit 211 and a storage unit 212.

[0085] <Main control unit 211> The main control unit 211 includes a processor and controls each element (including the elements shown in FIGS. 1 to 3B) of the ophthalmologic apparatus 1. The main control unit 211 is realized, for example, by cooperation between hardware including circuits and control software.

[0086] The imaging focusing lens 31 arranged in the imaging optical path and the focus optical system 60 arranged in the illumination optical path are moved integrally or in coordination with each other by an imaging focusing driver (not shown) under the control of the main controller 211. The retroreflector 41 provided on the measurement arm is moved by a retroreflector (RR) driver 41A under the control of the main controller 211. The OCT focusing lens 43 arranged on the measurement arm is moved by an OCT focusing driver 43A under the control of the main controller 211. The movement of the OCT focusing lens 43 can be coordinated with the movement of the imaging focusing lens 31 and the focus optical system 60. The retroreflector 114 provided on the reference arm is moved by a retroreflector (RR) driver 114A under the control of the main controller 211. Each of the mechanisms illustrated here typically includes an actuator such as a pulse motor operated under the control of the main controller 211. The optical scanner 44 provided on the measurement arm is operated under the control of the main controller 211. Furthermore, the main control unit 211 can control any element included in the ophthalmic apparatus 1, such as the polarization controller 103, the polarization controller 118, the attenuator 120, various light sources, various optical elements, various devices, and various mechanisms. The main control unit 211 may also be capable of controlling any peripheral equipment (apparatus, equipment, device, etc.) connected to the ophthalmic apparatus 1, and any equipment, equipment, device, etc. accessible by the ophthalmic apparatus 1.

[0087] The movement mechanism 150, for example, moves at least the fundus camera unit 2 three-dimensionally. In a typical example, the movement mechanism 150 includes an x-stage movable in ±x directions (left and right directions), an x-movement mechanism for moving the x-stage, a y-stage movable in ±y directions (up and down directions), a y-movement mechanism for moving the y-stage, a z-stage movable in ±z directions (depth direction), and a z-movement mechanism for moving the z-stage. Each of these movement mechanisms includes an actuator such as a pulse motor that operates under the control of the main controller 211.

[0088] <Storage section 212> The storage unit 212 stores various types of data. Examples of data stored in the storage unit 212 include image data of OCT images, image data of fundus images, and information about the subject's eye. The information about the subject's eye includes subject information such as a patient ID and name, identification information for the left eye / right eye, and electronic medical record information.

[0089] <Image forming unit 220> The image forming unit 220 forms OCT image data based on the data acquired by the spectrometer 130. The image forming unit 220 includes a processor. The image forming unit 220 is realized, for example, by cooperation between hardware including a circuit and image forming software.

[0090] The image forming unit 220 forms cross-sectional image data based on the data acquired by the spectroscope 130. This image forming process includes signal processing such as sampling (A / D conversion), noise removal (noise reduction), filtering, and fast Fourier transform (FFT), similar to conventional spectral domain OCT.

[0091] The image data formed by the image forming unit 220 is a data set including a group of image data (a group of A-scan image data) formed by imaging the reflection intensity profile of multiple A-lines (scan lines along the z-direction) arranged in the area where the OCT scan was applied.

[0092] The image data formed by the image forming unit 220 is, for example, one or more B-scan image data sets, or stack data formed by embedding multiple B-scan image data sets in a single three-dimensional coordinate system. The image forming unit 220 can also construct volume data (voxel data) by performing voxelization processing on the stack data. Stack data and volume data are typical examples of three-dimensional image data expressed in a three-dimensional coordinate system.

[0093] The image forming unit 220 can process the three-dimensional image data. For example, the image forming unit 220 can apply rendering to the three-dimensional image data to construct new image data. Rendering techniques include volume rendering, maximum intensity projection (MIP), minimum intensity projection (MIP), surface rendering, and multiplanar reconstruction (MPR). The image forming unit 220 can also construct projection data by projecting the three-dimensional image data in the z direction (A-line direction, depth direction). The image forming unit 220 can also construct a shadowgram by projecting a portion of the three-dimensional image data (three-dimensional partial image data) in the z direction. The three-dimensional partial image data is set, for example, by applying segmentation to the three-dimensional image data.

[0094] As described above, the ophthalmologic apparatus 1 of this embodiment is capable of performing OCTA. When performing OCTA, the ophthalmologic apparatus 1 repeatedly scans the same region of the fundus Ef a predetermined number of times. The image forming unit 220 constructs a motion contrast image from a data set collected by this repeated scanning. This motion contrast image is an angiographic image that emphasizes temporal changes in interference signals caused by blood flow in the fundus Ef. Typically, OCTA is applied to a three-dimensional region of the fundus Ef, and image data (three-dimensional angiographic image data) that represents the three-dimensional distribution of blood vessels in the fundus Ef is obtained.

[0095] The image forming unit 220 can construct any two-dimensional angiographic image data and / or any pseudo three-dimensional angiographic image data from this three-dimensional angiographic image data. For example, the image forming unit 220 can construct two-dimensional angiographic image data representing any cross section of the fundus oculi Ef by applying multiplanar reconstruction to the three-dimensional angiographic image data. The image forming unit 200 can also construct en face image data from image regions (slabs) corresponding to specific tissues identified by applying segmentation to the three-dimensional angiographic image data. Typically, en face image data is constructed for various depth areas such as the superficial retina, the deep retina, and the choroid.

[0096] Data Processing Unit 230 The data processing unit 230 performs various types of data processing. For example, the data processing unit 230 can apply image processing and analysis processing to OCT image data, and can apply image processing and analysis processing to observed image data or captured image data. The data processing unit 230 includes a processor. The data processing unit 230 is realized, for example, by cooperation between hardware including circuits and data processing software.

[0097] Next, the functional configuration of the ophthalmic apparatus 1 realized by the elements (hardware elements, software elements) shown in Figures 1 to 3A will be described. An example of the functional configuration of the ophthalmic apparatus 1 is shown in Figure 3B. This example provides a configuration for evaluating the ophthalmic apparatus 1 using a model eye 500.

[0098] <Model eyes 500> The model eye 500 is an exemplary embodiment of a model eye, and is attached to the face holder 450 via an attachment 460 in order to evaluate the performance of the ophthalmic apparatus 1. In this embodiment, the model eye 500 is placed in the same position as the subject's eye E. This makes it possible to use the alignment function of the ophthalmic apparatus 1 to align the data acquisition optical system 410 with the model eye 500, thereby facilitating the evaluation work. Furthermore, it becomes possible to evaluate not only the quality of the data acquired by the data acquisition optical system 410, but also the quality of the alignment performed by the alignment system 420.

[0099] 5 shows an exemplary configuration of a model eye 500. The model eye 500 of this example includes a cornea portion 510 (cornea-equivalent lens) corresponding to the cornea, an iris portion 520 corresponding to the iris, a lens portion 550 (lens-equivalent lens) corresponding to the crystalline lens, a vitreous body portion 560 corresponding to the vitreous body, and a fundus portion 570 corresponding to the fundus. The number of elements included in the model eye 500 (for example, the number of lenses) is arbitrary.

[0100] The iris portion 520 forms an opening 540 corresponding to the pupil. The iris portion 520 may be provided with a variable portion 530 for changing the size (opening diameter) of the opening 540. The variable portion 530 may be, for example, detachable from the iris portion 520, and multiple members corresponding to different opening diameters may be selectively applied. Alternatively, the variable portion 530 may be configured to be movable relative to the iris portion 520. The size of the opening 540 may be fixed. The vitreous portion 560 is filled with a liquid such as oil. The substance filled in the vitreous portion 560 is arbitrary and may be, for example, any gas, any liquid, or any solid. A gas (air) typically exists in the space between the cornea portion 510 and the lens portion 550. The substance provided in the space between the cornea portion 510 and the lens portion 550 is arbitrary and may be, for example, any gas, any liquid, or any solid.

[0101] The fundus 570 has a layered structure corresponding to the fundus of a human eye. For example, the fundus 570 has one or more layers corresponding to any tissue of the fundus of a human eye. Examples of fundus tissue include the internal limiting membrane, nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, external limiting membrane, photoreceptor layer, retinal pigment epithelium layer, Bruch's membrane, choroid, and sclera. The thickness and refractive index of each layer of the fundus 570 may be equivalent to the thickness and refractive index of one or more corresponding tissues. The shape of the fundus 570 is not limited to the flat shape shown in FIG. 5 and may be a curved shape such as a spherical shape or an elliptical shape. The fundus 570 may also have a structure corresponding to any part or tissue of a human eye. For example, the fundus 570 may have a structure corresponding to the macula, the optic disc, or blood vessels. The fundus 570 may also have a structure corresponding to any disease, pathological condition, or lesion, such as a structure corresponding to age-related macular degeneration (AMD) (drusen, etc.), a structure corresponding to retinal detachment, a structure corresponding to bleeding, a structure corresponding to a tumor, or a structure corresponding to atrophy.

[0102] The parameter values ​​of the eye model 500 may be designed to be equivalent to or similar to those of a human eye. The parameter values ​​of the eye model 500 may be obtained, for example, from a standard eye model or clinical data. Standard eye models include the Gullstrand eye model, the Navarro eye model, the Liou-Brennan eye model, the Badal eye model, the Arizona eye model, the Indiana eye model, any normalized eye model, and eye models equivalent to any of these. The eye model 500 may also be designed based on an eye with a disease such as high myopia. The eye model 500 may also have a structure corresponding to any disease, any pathological condition, or any lesion. For example, the eye model 500 may have a structure corresponding to any corneal disease, any lens disease, or the like. The eye model 500 may also have a structure corresponding to an artificial object. For example, the eye model 500 may have an intraocular lens (IOL) or a structure equivalent thereto.

[0103] The distance between the center position of the anterior surface of the cornea portion 510 (the position corresponding to the corneal apex) and the anterior surface of the fundus portion 570 may be designed based on the axial length of the human eye. Furthermore, the overall focal length of the cornea portion 510, the lens portion 550, and the vitreous portion 560 may be designed to be equal to the focal length of the human eye. For example, the model eye 500 may have a means (e.g., a spacer) for changing the optical distance between the lens portion 550 and the fundus portion 570. This makes it possible to change the refractive power of the model eye 500, and, for example, to perform imaging and measurement evaluation of an eye with a long axial length.

[0104] The reflectance of the front surface (surface facing the cornea 510) of the iris portion 520 (variable portion 530) may be designed to be equivalent to that of the human eye. This reflectance may be, for example, the reflectance of infrared wavelengths. Similarly, the front surface of the cornea portion 510 can also be designed to be equivalent to that of the human eye. Furthermore, the model eye 500 may be designed so that the entrance pupil of the iris portion 520 (variable portion 530, opening 540) is positioned at the same position as the entrance pupil of the iris of the human eye.

[0105] In order to prevent multiple reflections of the light used by the data acquisition optical system 410 (measurement light LS in this embodiment) and the light used by the alignment system 420 (wavelength band (e.g., infrared wavelength) detected by the anterior eye camera 300 in this embodiment) within the model eye 500, it is possible to provide an anti-reflective coating on the lenses, etc., or to apply anti-reflective paint to the internal components.

[0106] When performing alignment using two or more anterior eye cameras 300 (cameras sensitive to infrared wavelengths) as in the ophthalmologic apparatus 1 of this embodiment, the following parameter values ​​can be set, for example. First, the entrance pupil of the aperture 540 may be located at a position approximately 3.06 millimeters away from the cornea portion 510. The diameter of the aperture 540 may be set to a value within a range of 2 to 10 millimeters. Furthermore, the infrared light reflectance of the iris portion 520 (variable portion 530) may be set to a value within a range of 2.0 to 2.5 percent. With such a design, it becomes possible to perform alignment with the model eye 500 using the aperture 540 as a reference, similar to when performing alignment using the pupil of a human eye as a reference.

[0107] Even when another alignment method is used, the parameter values ​​of the model eye 500 are set according to the method. For example, when alignment is performed using a corneal reflection image (Purkinje image), the radius of curvature of the cornea portion 510 (the radius of curvature of the anterior surface of the cornea-equivalent lens) may be set to approximately 7.7 millimeters. Similarly, when alignment is performed using an optical lever, the radius of curvature of the cornea portion 510 (the radius of curvature of the anterior surface of the cornea-equivalent lens) can be set to approximately 7.7 millimeters.

[0108] The fundus portion 570 is constructed using a laminate. Some exemplary embodiments of the laminate applicable to the fundus portion 570 will be described with reference to Figures 6A, 6B, 7, 8, 9, 10, 11, and 12.

[0109] Figure 6A is a side view of an exemplary embodiment of a stack 600, and Figure 6B is a top view of the stack 600. The stack 600 includes a plurality of layers 620-1, 620-2, ..., 620-N, where N is an integer greater than or equal to 2. Any one of the plurality of layers 620-1, 620-2, ..., 620-N may be referred to as 620-n (n = 1, 2, ..., N). The plurality of layers 620-1, 620-2, ..., 620-N may have, for example, different scattering properties from one another.

[0110] The shape of the layer 620-n is arbitrary, and may be formed, for example, in the shape of a flat plate or a curved plate. Furthermore, of the multiple layers 620-1, 620-2, ..., 620-N, adjacent two layers 620-n and 620-(n+1) (n = 1, ..., N-1) are formed after one layer is cured. This prevents the materials of the layer 620-n and the layer 620-(n+1) from mixing with each other, allowing each layer to exhibit its intended properties. An example of a method for manufacturing such a laminate will be described later.

[0111] A plurality of layers 620-1, 620-2, ..., 620-N are formed on a substrate 610. The plurality of layers 620-1, 620-2, ..., 620-N and the substrate 610 are integrally configured. That is, the lower surface of the layer 620-N, which is the lowest of the plurality of layers 620-1, 620-2, ..., 620-N, is directly or indirectly bonded to the upper surface of the substrate 610. As an example of indirect bonding, an anti-reflection film can be disposed between the lower surface of the layer 620-N and the upper surface of the substrate 610.

[0112] The substrate 610 is typically formed of a transparent crystal. The material of the substrate 610 may be, for example, at least one of silicon dioxide (SiO), calcium fluoride (CaF), aluminum oxide (AlO), magnesium fluoride (MgF), zinc selenide (ZnSe), germanium (Ge), calcium carbonate (CaCO), polymethyl methacrylate resin, polyimide resin, polyethylene resin, and polycarbonate resin, but is not limited thereto. In some exemplary embodiments, the laminate may or may not include a substrate.

[0113] The layer 620-n has characteristics (structure, function, property) that simulate some tissues (layered tissue, membranous tissue) of the human fundus. For example, the layer 620-n has characteristics (structure, function, property) that correspond to one tissue of the human fundus, one sub-tissue of one tissue, a combination of two or more sub-tissues of one tissue, a combination of two or more tissues, or a combination of two or more of these.

[0114] Layer 620-n is formed by at least a substrate and microparticles dispersed in the substrate. In some exemplary embodiments, the substrates in layers 620-1, 620-2, ..., 620-N have (substantially) the same refractive index as one another. The substrate refractive index is determined according to the refractive index of the human fundus or one or more sub-tissues of the human fundus.

[0115] When the substrate refractive index is determined according to the refractive index of the human fundus, the substrate refractive index may be, for example, the standard refractive index of the human fundus as a whole or a refractive index approximate thereto. Alternatively, the substrate refractive index may be a refractive index (statistical value: average, median, etc.) statistically calculated from multiple standard refractive indices corresponding to multiple sub-tissues of the human fundus or a refractive index approximate thereto. Alternatively, the substrate refractive index may be the standard refractive index of a predetermined representative sub-tissue of the human fundus or a refractive index approximate thereto. The standard refractive index may be obtained, for example, from a standard eye model or clinical data.

[0116] When the substrate refractive index is determined according to the refractive index of one or more sub-tissues of the human fundus, the substrate refractive index may be, for example, the standard refractive index of a predetermined portion (one or more sub-tissues) of the human fundus or a refractive index approximate thereto. Alternatively, the substrate refractive index may be a refractive index (statistical value: average, median, etc.) statistically calculated from two or more standard refractive indices corresponding to two or more sub-tissues of the human fundus or a refractive index approximate thereto. Alternatively, the substrate refractive index may be the standard refractive index of a predetermined representative sub-tissue of the human fundus or a refractive index approximate thereto. The standard refractive index may be obtained, for example, from a standard eye model or clinical data. The one or more sub-tissues of the human fundus referenced to determine the substrate refractive index may include the human retina or one or more sub-tissues of the human retina, and / or the human choroid or one or more sub-tissues of the human choroid.

[0117] For example, the refractive index of the human retina is about 1.38, and it is believed that a substrate refractive index of about 1.40 or less is necessary to achieve a refractive index equivalent to that of the human fundus. To achieve this, an organosilicon compound can be used as the substrate material. This allows the substrate refractive index to be reduced to about 1.41. Furthermore, by using a fluorine compound as the substrate material, the substrate refractive index can be reduced to less than 1.40.

[0118] The properties considered in the design of the multiple layers 620-1, 620-2, . . . , 620-N are not limited to refractive properties (refractive index), but may be any optical properties such as transmission properties (transmittance, transmittance), diffusion properties (diffusivity, diffusion coefficient, diffusion degree), etc.

[0119] Furthermore, the scattering characteristics (degree of scattering, scattering intensity, scattering coefficient) are taken into consideration when designing the multiple layers 620-1, 620-2, ..., 620-N. As described above, the multiple layers 620-1, 620-2, ..., 620-N have different scattering characteristics from one another. The scattering characteristics of the layer 620-n are designed, adjusted, and controlled according to one or more of the layer characteristics, the substrate characteristics, the particle characteristics, and the combined characteristics of the substrate and the particle. To determine the scattering characteristics of the layer 620-n, for example, at least one of the type, size, and amount of the particle is referenced.

[0120] When the scattering characteristics of layer 620-n are determined at least according to the amount of added particulates, the amount of added particulates can be set, for example, but not limited to, in a range of 0.001 weight percent to 20 weight percent as a weight percent of the particulates relative to the substrate, and in some exemplary embodiments, the amount of added particulates can be set in a range of 0.04 weight percent to 4 weight percent.

[0121] When the thickness of layer 620-n is used to determine the scattering properties of layer 620-n, the layer thickness can be set in the range of 5 micrometers to 500 micrometers, but is not limited thereto. Also, the thickness of stack 600 can be, for example, in the range of 50 micrometers to 700 micrometers, but is not limited thereto.

[0122] To determine the scattering properties of layer 620-n, the material of the particles may be at least one of aluminum oxide (Al2O3), zinc oxide (ZnO), titanium oxide (TiO2), zirconium oxide (ZrO2), calcium carbonate (CaCO3), barium sulfate (BaSO4), polymethyl methacrylate resin, polyimide resin, polyethylene resin, and polycarbonate resin, but is not limited to these.

[0123] To determine the scattering properties of layer 620-n, the particle size of the particles can be set within the range of 10 nanometers to 100 micrometers, but is not limited to this.

[0124] To determine the scattering properties of layer 620-n, the shape of the particles may be at least one of, but is not limited to, a perfect sphere, a sphere, a needle, and a star.

[0125] FIG. 7 shows an example of the schematic configuration of two layers in the laminate thus constructed. Layer 620-n1 in FIG. 7 corresponds to one of the layers 620-1, 620-2, ..., 620-N in FIG. 6, and layer 620-n2 corresponds to the other layer. The refractive index of substrate 621-n1 of layer 620-n1 and the refractive index of substrate 621-n2 of layer 620-n2 are equal to each other. Furthermore, the two layers 620-n1 and 620-n2 have different scattering properties. To control these scattering properties, particles 622-n1 in layer 620-n1 and particles 622-n2 in layer 620-n2 are different from each other in at least both size and loading.

[0126] 6A and 6B, the stacked body 600 of this example is provided with liquid storage sections 630-1, ..., 630-M. Here, M is an integer greater than or equal to 1. Any one of the one or more liquid storage sections 630-1, ..., 630-M may be represented as 630-m (m = 1, ..., M). In other words, the stacked body 600 is provided with one or more liquid storage sections 630-1, ..., 630-M.

[0127] An example of a method for producing the liquid storage unit 630-m and an example of its configuration will be described with reference to FIG. 8. In this example, in the first step (A), a capillary (a thin tube, a tubular body) 640 that resembles the blood vessels of the fundus is prepared. Both ends of the capillary 640 are open. The material of the capillary 640 may be at least one of silicon dioxide (SiO2), polymethyl methacrylate resin, polypropylene, and vinylidene chloride resin, but is not limited to these. The inner diameter of the capillary 640 (the diameter of the hollow region) may be, for example, in the range of 10 micrometers to 300 micrometers.

[0128] Furthermore, although not shown, a liquid in which fine particles are suspended is prepared. The liquid base may be, for example, water or a water-based liquid, alcohol or an alcohol-based liquid, or glycol or a glycol-based liquid, but is not limited to these. The viscosity of the liquid may be, for example, within the range of 0.5 mPascal seconds to 100 mPascal seconds, but is not limited to these. The material of the fine particles added to the liquid may be, for example, a metal complex (copper complex, iron complex, etc.), but is not limited to these. The concentration of the fine particles added to the liquid may be, for example, within the range of 0.01 weight percent to 5.00 weight percent, but is not limited to these.

[0129] In the next step (B), a liquid 641 in which the particles are suspended is injected into the capillary 640. As a result, the hollow region of the capillary 640 is filled with the liquid 641 in which the particles are suspended.

[0130] In the next step (C), both ends (openings) of the capillary 640, whose hollow region is filled with the liquid 641 in which the particles are suspended, are closed. The openings can be closed by any method, for example, welding. The closed ends of the capillary 640 are denoted by reference numerals 642 and 643.

[0131] In the next step (D), a cover 644 is attached to cover the blocked portion 642 at the first end of the capillary 640, and a cover 645 is attached to cover the blocked portion 642 at the second end.

[0132] In the final step (E), adhesive 646 is filled into the gap between blocked portion 642 of capillary 640 and cover 644, and adhesive 647 is filled into the gap between blocked portion 643 and cover 645. By hardening adhesives 646 and 647, liquid 641 in which particles are suspended is completely sealed inside capillary 640. This results in liquid storage section 630-m in which liquid 641 in which particles are suspended is stored.

[0133] When multiple liquid storage sections 630-1, ..., 630-M (M is an integer of 2 or more) are provided, these liquid storage sections 630-1, ..., 630-M may have different features (configurations, functions, properties) from one another. For example, the multiple liquid storage sections 630-1, ..., 630-M may have different forms from one another. Typically, the multiple liquid storage sections 630-1, ..., 630-M may have different shapes and / or different dimensions (length, thickness, diameter, etc.). Furthermore, the multiple liquid storage sections 630-1, ..., 630-M may be made of different materials from one another.

[0134] The multiple liquid storage units 630-1, ..., 630-M may be configured so that the movement speeds of particles suspended in the stored liquid differ from one another. To this end, any parameter related to the liquid and / or any parameter related to the particles may be taken into consideration. The parameter taken into consideration may be any parameter that affects the Brownian motion of particles in the liquid. For example, the movement speed of particles suspended in the liquid can be controlled by adjusting any parameter among the viscosity of the liquid, the temperature of the liquid, and the morphology (shape, size) of the particles. In other words, the multiple liquid storage units 630-1, ..., 630-M may store liquids of different viscosities, liquids of different temperatures, or liquids in which particles of different sizes are suspended.

[0135] For example, as shown in FIG. 9A, the liquid storage unit 630-m may be tilted relative to a predetermined axial direction 650. The axial direction 650 may be defined by the model eye (layered structure 600A, 600B) and / or the evaluation method. For example, the axial direction 650 may correspond to the ocular axis of the model eye (layered structure 600A, 600B) having a structure resembling an eye. Alternatively, the axial direction 650 may correspond to the direction in which multiple layers in the layered structure (600A, 600B) are stacked (i.e., the thickness direction, depth direction, etc.). Alternatively, the axial direction 650 may correspond to the axial direction used in OCT (i.e., the z direction, A-scan direction, measurement light incident direction, etc.). By tilting the liquid storage unit 630-m in this manner, it is possible to obtain blood flow parameters (e.g., blood flow velocity, blood volume, etc.) in addition to the presence or absence of blood flow. In other words, it is possible to evaluate the Doppler shift due to the direction of blood flow.

[0136] When multiple liquid storage units 630-1, ..., 630-M (M is an integer of 2 or greater) are provided, at least one of these liquid storage units 630-1, ..., 630-M may be arranged at an inclination with respect to the axial direction 650. Furthermore, at least two of these liquid storage units 630-1, ..., 630-M may be arranged at different inclination angles with respect to the axial direction 650. For example, as shown in FIG. 9(B), both of the two liquid storage units 630-m1 and 630-m2 may be inclined with respect to the axial direction 650, and the inclination angle of the liquid storage unit 630-m1 with respect to the axial direction 650 may be different from the inclination angle of the liquid storage unit 630-m2 with respect to the axial direction 650. This makes it possible to obtain information representing the relationship between the inclination angle and the blood flow parameter. For example, it is possible to obtain the blood flow parameter for each of the different inclination angles, and perform an evaluation accordingly. It is also possible to obtain the change and sensitivity of the blood flow parameter in response to a change in the inclination angle, and perform an evaluation accordingly.

[0137] When an eye model including a laminated body made of multiple layers, such as the eye model 500 of this example, is used, the arrangement of the multiple layers and the liquid storage units may be arbitrary. For example, as shown in FIG. 6A, a liquid storage unit may be disposed between layers. Furthermore, as shown in FIG. 10(A), a liquid storage unit 630-m may be disposed within any layer 620-n of the laminated body. Furthermore, as shown in FIG. 10(B), a liquid storage unit 630-m may be disposed within layer 620-n of the laminated body, and a liquid storage unit 630-(m+1) may be disposed within layer 620-(n+1). The number of layers provided with a liquid storage unit may be arbitrary, and the two layers each provided with a liquid storage unit may or may not be adjacent to each other. As shown in FIG. 10(C), a single liquid storage unit 630-m may be disposed across two layers 620-n and 620-(n+1) of the laminated body. The liquid storage unit may be arranged across three or more layers. Another example in which a single liquid storage unit 630-m is arranged across two layers 620-n and 620-(n+1) is shown in Figure 10(D). In this example, the liquid storage unit 630-m is arranged at an angle with respect to a predetermined axial direction. These are some examples of eye models that mimic the distribution of blood vessels in the fundus.

[0138] In order to easily determine the part of the model eye (fundus, laminate) to which OCT scan is applied for performance evaluation of the ophthalmic device 1, a configuration can be adopted that allows the liquid storage section or its position to be recognized from the outside.

[0139] In some exemplary embodiments, a configuration in which a portion of the liquid storage portion is exposed from the laminate can be employed. FIG. 11 is a top view of a laminate 600C having such a configuration. A central portion 630a of a liquid storage portion 630 provided in the laminate 600C is embedded in the laminate 600C, and both end portions 630b and 630c are exposed from the laminate 600C. The user can determine the position of the liquid storage portion 630 by referring to the exposed end portions 630b and 630c. This can be used to determine the range in which to apply OCT scans for performance evaluation and the orientation in which to place the model eye.

[0140] The present invention is not limited to the above-described embodiments, but may be modified to provide a similar effect. For example, marks indicating the positions of the liquid storage units embedded in the laminate may be provided on the outer surfaces of the eye model, the fundus, and the laminate. Alternatively, the laminate may be formed using a transparent material.

[0141] The orientation of the liquid storage unit when performing an OCT scan for evaluating the performance of the ophthalmologic apparatus 1 may be arbitrary. Furthermore, it is possible to configure one or more of the model eye, the fundus, and the laminate to be movable and / or changeable, or to configure one or more of a portion of the model eye, a portion of the fundus, and a portion of the laminate to be movable and / or changeable. For example, as shown in FIGS. 12(A) and 12(B), the laminate 600D can be configured to be rotatable around a predetermined axis, thereby enabling the orientation of the liquid storage unit 630D to be changed.

[0142] In some exemplary embodiments, a liquid having a high viscosity such that Brownian motion of particles does not substantially occur may be enclosed within the capillary. The purpose of evaluating OCTA function is to obtain a signal (motion signal) representing the motion of particles in the liquid. According to this embodiment, a signal (reference signal) representing a state in which the motion of particles is substantially zero can be obtained and this reference signal can be used to analyze the motion signal. For example, the reference signal can be used as an offset to correct the motion signal. Furthermore, noise in the motion signal can be removed by treating the reference signal as a signal representing inherent noise arising from the OCTA elements (optical system, processing system, etc.). The reference signal can also be used to evaluate and calibrate a model eye used to acquire the motion signal (i.e., a model eye containing a capillary filled with a liquid having a low viscosity that causes Brownian motion of particles). For example, the difference (e.g., difference, ratio, etc.) between the reference signal and the motion signal can be referenced to adjust the parameters (e.g., temperature) of the model eye used to acquire the motion signal.

[0143] <Face holder 450, attachment 460> The face holder 450 is a member that holds the face of the subject to fix the position of the subject's eye E. A typical ophthalmic device is provided with a chin rest and a forehead rest (see, for example, Japanese Patent Application Laid-Open No. 2010-200905 and Japanese Patent Application Laid-Open No. 2015-139527). The subject's chin is placed on the chin rest. The subject's forehead is placed (contacted) against the forehead rest.

[0144] The attachment 460 is a member for attaching the model eye 500 to the ophthalmic apparatus 1. Typically, the attachment 460 is interposed between the model eye 500 and the ophthalmic apparatus 1. In some exemplary embodiments, the model eye 500 and the attachment 460 may be integrally configured, but in this embodiment, the model eye 500 is detachably attached to the attachment 460. For example, the model eye 500 is attached to the attachment 460, and the attachment 460 is attached to the face holder 450. In other words, the model eye 500 is indirectly attached to the ophthalmic apparatus 1 via the attachment 460.

[0145] The location of the ophthalmologic apparatus 1 where the model eye 500 (attachment 460) is attached is not limited to the face holder 450. For example, it is possible to adopt a configuration in which the model eye 500 is attached to the outer surface of a housing that houses the data acquisition optical system 410, or a configuration in which the model eye 500 is built into the housing. When the model eye 500 is built into the housing, the model eye 500 may be configured to be insertable into the optical path of the data acquisition optical system 410, or may be arranged in an optical path branched from the optical path of the data acquisition optical system 410. In the latter case, for example, when a performance evaluation is performed using the model eye 500, a total reflection mirror or a beam splitter is inserted into the optical path of the data acquisition optical system 410, and light from the data acquisition optical system 410 (e.g., measurement light LS) is guided to the model eye 500 via the branched optical path.

[0146] Data Acquisition Optical System 410 The data acquisition optical system 410 is an optical system for acquiring data of the subject's eye E. When evaluating the ophthalmic apparatus 1, the data acquisition optical system 410 acquires data from the model eye 500 in the same manner as when acquiring data from the subject's eye E. For example, the ophthalmic apparatus 1 of this embodiment can acquire data from the fundus 570 by applying an OCT scan to the model eye 500. Furthermore, the ophthalmic apparatus 1 of this embodiment can photograph the fundus 570 of the model eye 500 using the fundus camera unit 2.

[0147] <Alignment System 420> The alignment system 420 is configured to align the data acquisition optical system 410 with the model eye 500 placed at a predetermined position.

[0148] In this embodiment, the alignment system 420 includes two anterior eye cameras 300, a processing unit 430, and a movement mechanism 150. As described above, the two anterior eye cameras 300 include image sensors sensitive to infrared wavelengths and are configured to capture images of the model eye 500 placed at a predetermined position from two different directions. The movement mechanism 150 is configured to move the data acquisition optical system 410.

[0149] Processing section 430 The processing unit 430 controls the moving mechanism 150 based on two or more images of the eye model 500 acquired by the two anterior eye cameras 300.

[0150] The processing unit 430 is configured to execute, for example, the processing described in Japanese Patent Application Laid-Open No. 2013-248376 filed by the present applicant. More specifically, the processing unit 430 first analyzes each of the two images of the model eye 500 acquired by the two anterior eye cameras 300 to identify the pupil region in each image.

[0151] Next, the processing unit 430 calculates the amount of three-dimensional movement of the data acquisition optical system 410 based on the two pupil regions identified from the two images. Trigonometry is used for this calculation.

[0152] Furthermore, the processing unit 430 controls the movement mechanism 150 based on the calculated three-dimensional movement amounts. More specifically, the processing unit 430 controls the movement mechanism 150 so as to move the data acquisition optical system 410 by the calculated three-dimensional movement amounts (movement amounts in the x direction, y direction, and z direction).

[0153] For details of the processing performed by the processing unit 430, please refer to a series of documents by the present applicant that relate to inventions using two or more anterior eye cameras, such as Japanese Patent Application Laid-Open No. 2013-248376 and Japanese Patent Application Laid-Open No. 2014-113385. The processing unit 430 is realized by, for example, the main control unit 211 and the data processing unit 230.

[0154] The ophthalmologic apparatus 1 of this embodiment may use the alignment optical system 50 to align the data acquisition optical system 410 with the model eye 500. In this case, auto-alignment using an alignment index (described above) is applied to the model eye 500.

[0155] Some exemplary embodiments of the ophthalmic apparatus may be capable of performing XY alignment and / or Z alignment described in Japanese Patent Application Laid-Open No. 2018-164616 filed by the present applicant. XY alignment is an alignment method that uses a corneal reflection image (Purkinje image), and Z alignment is an alignment method that uses an optical lever.

[0156] When applying a technique using a corneal reflection image (Purkinje image) to the alignment of data acquisition optical system 410 with model eye 500, for example, the configuration shown in Fig. 13A can be used instead of the configuration shown in Fig. 3B. In the configuration example shown in Fig. 13A, alignment system 420 shown in Fig. 3B is replaced with alignment system 420A. Among the elements shown in Fig. 13A, elements similar to those in Fig. 3B are designated by the same reference numerals, and unless otherwise specified, description of those elements will not be repeated.

[0157] The model eye 500 of this example includes at least a corneal portion (510) corresponding to the cornea, and the radius of curvature of this corneal portion is set to approximately 7.7 mm.

[0158] Alignment system 420A includes projection unit 421A, imaging unit 422A, processing unit 430A, and movement mechanism 150.

[0159] The projection unit 421A projects a light beam onto the model eye 500. In particular, the projection unit 421A projects the light beam onto the model eye 500 from the front. Typically, the projection unit 421A is configured to project a parallel light beam onto the model eye 500 through a part of the optical path of the data acquisition optical system 410. As a result, a bright spot image (corneal reflection image, Purkinje image) is formed on the cornea of ​​the model eye 500.

[0160] The photographing unit 422A photographs the model eye 500 in a state where a light beam is projected by the projection unit 421A. A corneal reflection image is depicted in the image of the model eye 500 obtained by the photographing unit 422A. The image of the model eye 500 obtained by the photographing unit 422A is input to the processing unit 430A. The photographing unit 422A is an area sensor in which multiple light receiving elements (photoelectric conversion elements) are arranged two-dimensionally.

[0161] The processing unit 430A analyzes the image of the model eye 500 acquired by the imaging unit 422A to identify the corneal reflection image. This analysis includes, for example, image processing based on changes in brightness values ​​(for example, edge detection).

[0162] Furthermore, the processing unit 430A controls the moving mechanism 150 based on the corneal reflection image identified from the image of the model eye 500. For example, the processing unit 430A calculates the deviation of the corneal reflection image from a predetermined reference position (for example, a position corresponding to the optical axis of the data acquisition optical system 410), and controls the moving mechanism 150 to cancel this deviation (so that the corneal reflection image is positioned at the reference position). This makes it possible to guide the optical axis of the data acquisition optical system 410 to the apex position of the cornea of ​​the model eye 500.

[0163] For details of the processing performed by the processing unit 430A, see, for example, Japanese Patent Application Laid-Open No. 2018-164616 and Japanese Patent Application Laid-Open No. 10-024019. The processing unit 430A is realized by, for example, the main control unit 211 and the data processing unit 230.

[0164] When applying the technique using an optical lever to the alignment of the data acquisition optical system 410 with respect to the model eye 500, for example, the configuration shown in Figure 13B can be adopted instead of the configuration shown in Figure 3B. In the configuration example shown in Figure 13B, alignment system 420 shown in Figure 3B is replaced with alignment system 420B. Among the elements shown in Figure 13B, elements that are similar to those in Figure 3B are designated by the same reference numerals, and unless otherwise specified, descriptions of those elements will not be repeated.

[0165] The model eye 500 of this example includes at least a corneal portion (510) corresponding to the cornea, and the radius of curvature of this corneal portion is set to approximately 7.7 mm.

[0166] Alignment system 420B includes projection unit 421B, imaging unit 422B, processing unit 430B, and movement mechanism 150.

[0167] The projection unit 421B projects a light beam onto the model eye 500. In particular, the projection unit 421B projects the light beam obliquely onto the model eye 500. Typically, the projection unit 421B is configured to project a parallel light beam onto the model eye 500 from a position outside the optical path of the data acquisition optical system 410. As a result, the light beam projected onto the cornea of ​​the model eye 500 is reflected by the surface of the cornea.

[0168] The image capturing unit 422B is disposed in a direction approximately symmetrical to the direction in which the light beam is projected by the projection unit 421B, with respect to the optical axis of the data acquisition optical system 410. Typically, the projection unit 421B and the image capturing unit 422B are disposed in positions approximately symmetrical to each other with respect to the optical axis of the data acquisition optical system 410. The image capturing unit 422B is typically a line sensor in which a plurality of light receiving elements are arranged one-dimensionally. Note that the image capturing unit 422B may also be an area sensor in which a plurality of light receiving elements are arranged two-dimensionally. When the distance between the model eye 500 and the data acquisition optical system 410 is within a predetermined range, the light beam emitted from the projection unit 421B is reflected by the cornea (corneal reflected light) and is detected by the image capturing unit 422B. When the corneal reflected light is not detected by the image capturing unit 422B, the image obtained by the image capturing unit 422B is an all-black image. On the other hand, when the corneal reflected light is detected by the image capturing section 422B, the image obtained by the image capturing section 422B includes a bright spot image. The image obtained by the image capturing section 422B is input to the processing section 430B.

[0169] The processing unit 430B analyzes the image acquired by the photographing unit 422B to determine whether or not a bright spot image is present, and if no bright spot image is present, sends a predetermined control signal to the moving mechanism 150. On the other hand, if a bright spot image is present, the processing unit 430B identifies the position of the bright spot image and determines the deviation of the position of the bright spot image from a predetermined reference position. In other words, the processing unit 430B identifies the address of the light receiving element that detected the corneal reflected light among the multiple light receiving elements of the photographing unit 422B, and determines the deviation between the address of this light receiving element and a predetermined reference address.

[0170] Furthermore, the processing unit 430B controls the moving mechanism 150 based on the deviation thus identified. For example, the processing unit 430B controls the moving mechanism 150 so as to cancel out this deviation (so that the corneal reflected light is detected by the light receiving element at the reference address). This makes it possible to guide the distance between the model eye 500 and the data acquisition optical system 410 to a predetermined working distance.

[0171] For details of the processing performed by the processing unit 430B, see, for example, Japanese Patent Application Laid-Open No. 2018-164616 and Japanese Patent Application Laid-Open No. 2015-146859. The processing unit 430B is realized by, for example, the main control unit 211 and the data processing unit 230.

[0172] <Evaluation Section 440> For example, after alignment is performed by the alignment system 420 (420A, 420B), the data acquisition optical system 410 acquires data of the model eye 500. For example, the ophthalmologic apparatus 1 aligns the data acquisition optical system 410 with respect to the model eye 500 by the alignment system 420, and then applies an OCT scan to the model eye 500 by the data acquisition optical system 410. This OCT scan is typically a scan for OCTA, and applies scans to a specific portion of the model eye 500 a predetermined number of times.

[0173] The evaluation unit 440 generates evaluation information based on data of the model eye 500 acquired after alignment. For example, the evaluation unit 440 may be configured to generate data quality evaluation information that indicates the quality of the data acquired by the data acquisition optical system 410. The evaluation unit 440 may also be configured to generate alignment quality evaluation information that indicates the quality of the alignment performed by the alignment system.

[0174] When generating data quality evaluation information, the evaluation unit 440 executes a predetermined data quality evaluation process. For example, as described above, if the fundus 570 of the eye model 500 has a layered structure corresponding to the fundus of a human eye, the ophthalmologic apparatus 1 applies an OCT scan to the fundus 570 using the data acquisition optical system 410. The image forming unit 220 forms an image of the fundus 570 from the OCT data acquired by the data acquisition optical system 410. The evaluation unit 440, for example, compares the formed image of the fundus 570 with a predetermined evaluation image. This evaluation image is, for example, an image of the fundus 570 with high data quality. The evaluation unit 440 can generate data quality evaluation information based on the result of comparing the image of the fundus 570 with the evaluation image.

[0175] In this embodiment, the evaluation unit 440 is configured to perform quality evaluation of the OCTA data. The ophthalmic apparatus 1 applies OCT scans to a region of the fundus 570, including at least a portion of at least one of the multiple liquid storage units 630-1, ..., 630-M, a predetermined number of times using the data acquisition optical system 410. For example, the ophthalmic apparatus 1 may repeatedly apply OCT scans to the entire fundus 570. The image forming unit 220 constructs a motion contrast image from the data set collected by the repeated OCT scans. This motion contrast image is a simulated angiography image that emphasizes temporal changes in interference signals caused by the Brownian motion of particles in the liquid storage unit 630-m. This simulated angiography image is three-dimensional image data, and the image forming unit 220 can construct any two-dimensional image data and / or any three-dimensional image data from this three-dimensional image data, as described above. The evaluation unit 440 can generate quality evaluation information of the OCTA data, for example, by comparing the constructed image of the fundus 570 (OCTA image) with a predetermined evaluation image.

[0176] As another example of generating data quality evaluation information, the evaluation unit 440 can determine the value of a predetermined evaluation parameter representing data quality by analyzing the data acquired by the data acquisition optical system 410. The evaluation parameter may be, for example, an image quality evaluation parameter such as contrast or SNR. The evaluation parameter may also be, for example, a measurement quality evaluation parameter such as a measurement accuracy parameter or a measurement precision parameter.

[0177] When generating the alignment quality evaluation information, the evaluation unit 440 executes a predetermined alignment quality evaluation process. For example, the evaluation unit 440 can evaluate the alignment quality based on the time required for alignment, the processing content, and the results. The evaluation unit 440 can also evaluate the alignment error with respect to the liquid storage unit 630-m as the alignment target.

[0178] In some exemplary embodiments, the evaluation unit 440 can generate alignment quality evaluation information based on the length of time (alignment time) from the start of alignment to reaching a suitable alignment state (e.g., a state in which the alignment error is within a predetermined range). For example, the evaluation unit 440 can compare the alignment time with a predetermined threshold, and evaluate the alignment time as "low quality" if it exceeds the threshold, and evaluate the alignment time as "high quality" if it is equal to or less than the threshold. Alternatively, the evaluation unit 440 can be configured to determine to which range the alignment time belongs among a plurality of predetermined ranges (high quality range, acceptable range, poor range), and generate alignment quality evaluation information based on the range to which the alignment time belongs.

[0179] In some exemplary embodiments, the evaluation unit 440 can generate alignment quality evaluation information based on the content of processing performed by the alignment system 420 (420A, 420B). For example, the evaluation unit 440 can generate alignment quality evaluation information based on the number of iterations of the alignment operation performed from the start of alignment until a suitable alignment state is reached. The alignment operation is, for example, the number of times the processing unit 430 (430A, 430B) processes images from the anterior eye camera 300. For example, the evaluation unit 440 can compare the number of iterations of the alignment operation with a predetermined threshold and evaluate the quality as "low quality" if the number of iterations exceeds the threshold, or evaluate the quality as "high quality" if the number of iterations is equal to or less than the threshold. Alternatively, the evaluation unit 440 can be configured to determine which of a plurality of predetermined ranges (high quality range, acceptable range, poor range) the number of iterations belongs to and generate alignment quality evaluation information based on the range to which the number of iterations belongs.

[0180] In some exemplary embodiments, the evaluation unit 440 can generate alignment quality evaluation information based on the results of processing performed by the alignment system 420 (420A, 420B). For example, the evaluation unit 440 can determine the alignment state (e.g., alignment error) reached by the alignment system 420 performing an alignment operation over a predetermined time period, and generate alignment quality evaluation information based on this alignment error. For example, the evaluation unit 440 can compare the alignment error with a predetermined threshold, and evaluate the alignment error as "low quality" if it exceeds the threshold, and as "high quality" if it is equal to or less than the threshold. Alternatively, the evaluation unit 440 can be configured to determine to which of a plurality of predetermined ranges (high quality range, acceptable range, poor range) the alignment error belongs, and generate alignment quality evaluation information based on the range to which the alignment error belongs.

[0181] As mentioned above, temperature is a parameter that affects the Brownian motion of particles in a liquid. Here, a configuration in which the temperature of a liquid can be controlled will be described with reference to FIG. 14. The configuration shown in FIG. 14 is the configuration shown in FIG. 3B to which a temperature control unit 470 has been added. Note that configurations capable of controlling the liquid temperature are not limited to this. For example, the temperature control unit 470 or an element equivalent thereto may be added to any of a configuration equivalent to the configuration shown in FIG. 3B, a configuration shown in FIG. 13A or an equivalent thereto, a configuration shown in FIG. 13B or an equivalent thereto, and any other configuration.

[0182] In the first embodiment, the temperature control unit 470 is configured to maintain a constant temperature of the liquid stored in the liquid storage unit 630-m. For example, the temperature control unit 470 of this embodiment includes a first means for changing the amount of thermal energy of the liquid, a second means for measuring the temperature of the liquid, and a third means for controlling the first means so that the temperature measured by the second means becomes a predetermined value. Each means may have any known configuration. For example, the first means may be a means for outputting hot and / or cold air, the second means may be a thermistor or thermocouple sensor, and the third means may be a processor. According to this embodiment, the temperature of the liquid stored in the liquid storage unit 630-m can be maintained substantially constant, thereby stabilizing the state of Brownian motion (such as the movement speed of the particles) of the particles floating in the liquid. This can improve the accuracy, precision, and reproducibility of performance evaluation of the ophthalmic device 1.

[0183] In the second embodiment, the temperature control unit 470 is configured to change the temperature of the liquid stored in the liquid storage unit 630-m. The temperature control unit 470 of this embodiment may be the same as that of the first embodiment. According to this embodiment, the temperature of the liquid stored in the liquid storage unit 630-m can be changed to a desired temperature, and therefore the state of Brownian motion (such as the movement speed of the particles) of the particles floating in the liquid can be guided to a desired state. This makes it possible to improve the accuracy, precision, reproducibility, etc. of the performance evaluation of the ophthalmologic apparatus 1.

[0184] <Operation> An example of the operation of the ophthalmologic apparatus 1 according to this embodiment will be described below. An example of the operation of the ophthalmologic apparatus 1 is shown in FIG.

[0185] First, the model eye 500 is placed in a predetermined position for evaluating the ophthalmologic apparatus 1 (S1). In this embodiment, for example, two model eyes 500 (a left model eye and a right model eye) are attached to the face holder 450 using an attachment 460. Note that the model eye 500 may be attached directly to a chin rest, directly or indirectly to a forehead rest, or directly or indirectly to another location on the ophthalmologic apparatus 1.

[0186] After the eye model 500 is attached to the ophthalmic apparatus 1, the ophthalmic apparatus 1 starts alignment with the eye model 500 (S2). This alignment is performed using, for example, any of the alignment system 420 in Fig. 3B, the alignment system 420A in Fig. 13A, and the alignment system 420B in Fig. 13B.

[0187] The alignment may be performed, for example, until a suitable alignment state is achieved, or for a predetermined time, or until a predetermined number of iterations of the alignment operation are performed. Note that the suitable alignment state referred to here is a state suitable for evaluating OCTA functionality, and typically, a state in which an OCT scan is applied to at least one liquid container 630-m.

[0188] Once the alignment is complete (S3), the ophthalmologic apparatus 1 applies an OCT scan to the eye model 500 (S4). This OCT scan is an OCT scan of the fundus 570, and is a repetitive OCT scan for OCTA. Note that an OCT scan of a portion corresponding to the anterior segment (one or more of the cornea 510, iris 520, variable portion 530, aperture 540, and lens 550) may be (additionally) performed. Also, a scan for evaluating OCT function for structural imaging and / or a scan for evaluating OCT function for functional imaging other than OCTA may be (additionally) performed.

[0189] The ophthalmologic apparatus 1 causes the image forming unit 220 to form an OCTA image from the data set acquired in the repetitive OCT scans of step S4 (S5).

[0190] Furthermore, the ophthalmic apparatus 1 generates evaluation information based on the OCTA image formed in step S5 using the evaluation unit 440 (S6). For example, the ophthalmic apparatus 1 can generate data quality evaluation information about the OCTA function using the evaluation unit 440. Furthermore, the ophthalmic apparatus 1 can generate alignment quality evaluation information based on the data obtained about the alignment in step S3 using the evaluation unit 440.

[0191] The evaluation information generated in step S6 is displayed, for example, on the display unit 241. The evaluation information generated in step S6 is also transmitted from the ophthalmologic apparatus 1 to an external device. The evaluation information generated in step S6 is also recorded on a recording medium. This completes the process of this operation example.

[0192] <OCTA image of a model eye> 16 shows OCTA images obtained by an exemplary embodiment of an ophthalmic device. Fig. 16(A) is a front view (OCTA front image) 700 of an OCTA image of an eye model provided with three liquid storage sections. The three liquid storage sections provided in this eye model have the following characteristics: the three capillaries corresponding to the three liquid storage sections have the same configuration (shape, length, diameter, etc.); they contain liquids of different viscosities (a relatively low viscosity liquid, a relatively medium viscosity liquid, and a relatively high viscosity liquid); and the three types of liquids with different viscosities have the same amount (weight percent) of fine particles of the same configuration (material, size, etc.) added to them.

[0193] An OCTA front image 700 depicts three images (three pseudo blood vessel images) 701, 702, and 703 corresponding to the three liquid storage sections. The pseudo blood vessel image 701 is an image resulting from the Brownian motion of particles in a relatively low-viscosity liquid (i.e., an image representing changes in light scattering due to particles undergoing Brownian motion). The pseudo blood vessel image 702 is an image resulting from the Brownian motion of particles in a relatively medium-viscosity liquid (i.e., an image representing changes in light scattering due to particles undergoing Brownian motion). The pseudo blood vessel image 703 is an image resulting from the Brownian motion of particles in a relatively high-viscosity liquid (i.e., an image representing changes in light scattering due to particles undergoing Brownian motion).

[0194] That is, the pseudo blood vessel image 701 is an image representing light scattering by particles moving through the liquid at a relatively high speed, and is an image of a relatively high-intensity signal. The pseudo blood vessel image 702 is an image representing light scattering by particles moving through the liquid at a relatively medium speed, and is an image of a relatively medium-intensity signal. The pseudo blood vessel image 703 is an image representing light scattering by particles moving through the liquid at a relatively low speed, and is an image of a relatively low-intensity signal.

[0195] Image 710 in Fig. 16(B) is a B-scan image taken along the longitudinal direction of pseudo blood vessel image 701. Image 720 in Fig. 16(C) is a B-scan image taken along the longitudinal direction of pseudo blood vessel image 702. Image 730 in Fig. 16(D) is a B-scan image taken along the longitudinal direction of pseudo blood vessel image 703.

[0196] The B-scan image 710 includes an image (pseudo blood vessel image) 711 corresponding to the pseudo blood vessel image 701. The pseudo blood vessel image 711 is an image caused by the Brownian motion of particles in a liquid with a relatively low viscosity. In other words, the pseudo blood vessel image 711 is an image caused by particles moving in the liquid at a relatively high speed, and represents a relatively high-intensity signal.

[0197] The B-scan image 720 includes an image (pseudo blood vessel image) 721 corresponding to the pseudo blood vessel image 702. The pseudo blood vessel image 721 is an image resulting from the Brownian motion of particles in a liquid of relatively medium viscosity. In other words, the pseudo blood vessel image 721 is an image resulting from particles moving in the liquid at a relatively medium speed, and represents a signal of relatively medium intensity.

[0198] The B-scan image 730 includes an image (pseudo blood vessel image) 731 corresponding to the pseudo blood vessel image 703. The pseudo blood vessel image 731 is an image caused by the Brownian motion of particles in a relatively highly viscous liquid. In other words, the pseudo blood vessel image 731 is an image caused by particles moving relatively slowly in the liquid, and represents a relatively low-intensity signal.

[0199] The intensity of the signal corresponding to the pseudo blood vessel image increases as the contrast difference (contrast ratio) between the pseudo blood vessel image and its surroundings increases, and decreases as the contrast difference (contrast ratio) decreases.

[0200] 16, by using the eye model according to the exemplary embodiment, an OCTA image similar to an OCTA image of a human fundus can be obtained. In other words, it can be said that the eye model according to the exemplary embodiment has characteristics similar to those of a human fundus, at least with respect to characteristics that can be detected by OCTA.

[0201] <Method for manufacturing laminate> A laminate manufacturing method according to an exemplary embodiment will now be described. Figure 17 shows an example of a method for manufacturing a laminate in which a liquid storage unit is disposed between layers. As mentioned above, the location of the liquid storage unit is not limited to this (see, for example, Figures 9 to 12). When the liquid storage unit is disposed at a location other than between layers, a manufacturing method can be adopted that corresponds to the location of the liquid storage unit.

[0202] 17, it is assumed that some design aspects of the stack are preset, such as the number of layers, the number of liquid containers, and the locations of the liquid containers.

[0203] Furthermore, design items related to the liquid storage section may also be set in advance. For example, the form of the liquid storage section (shape, length, diameter, etc.), the liquid material, the viscosity of the liquid, the material of the microparticles, the amount of microparticles to be added to the liquid, etc. may be determined in advance.

[0204] Furthermore, the shape and dimensions (area, thickness, volume, etc.) of each layer may also be set in advance. The shape and dimensions of each layer do not have to be set in advance; for example, the shape and dimensions of the layer may be determined and adjusted depending on the state of the formed layer. In this example, for each of the multiple layers included in the target laminate, the amount of base material separated in step S11-1 and the amount of fine particles separated in step S11-2 are set in advance (see, for example, the amount of fine particles added, described above).

[0205] In the laminate manufacturing method of this example, first, a predetermined number of liquid storage sections are created in accordance with predetermined design specifications (S10). The liquid storage sections are created in the manner described above (see, for example, FIG. 8).

[0206] Next, the materials for forming the first layer are weighed (S11). In this example, for the first layer, the base material is weighed (S11-1) and the fine particles to be added thereto are weighed (S11-2). As a result, a predetermined amount of base material and a predetermined amount of fine particles are obtained for forming the first layer.

[0207] Next, the predetermined amount of particles obtained in step S11-2 is added to the predetermined amount of base material obtained in step S11-1 (S12).

[0208] Next, the base material containing the particles introduced in step S12 is stirred, and degassing (degassing) is performed to remove gas dissolved in the base material (S13). Any known method can be used for stirring and degassing. This removes unnecessary gas from the base material and disperses the particles in the base material.

[0209] Next, the mixture obtained in step S13 (a substance containing at least the base material and the fine particles) is processed into a layer (S14). Any known method may be used for this layer processing, and for example, a spin coating method may be applied.

[0210] Next, the mixture processed into layers in step S14 is hardened (S15). This hardening process can be performed by, for example, a physical hardening method using heat or a chemical hardening method using a predetermined substance. This completes the formation of the first layer.

[0211] If the last layer of the preset number of layers was formed in the immediately preceding step S15 (S16: Yes), the target laminate is completed (end). On the other hand, if the layer formed in the immediately preceding step S15 is not the last layer of the preset number of layers (S16: No), the process proceeds to the next step S17. Note that in this example, two or more layers are formed, so at this stage where only the first layer has been formed, the determination is "No" and the process proceeds to step S17.

[0212] If "No" is selected in step S16, one or more of the predetermined number of liquid storage units created in step S11 are installed at a predetermined position on the top surface of the layer formed in the immediately preceding step S15. Note that step S17 is only performed if a liquid storage unit is to be placed between the layer formed in the immediately preceding step S15 and the layer to be formed immediately thereafter. In other words, if "No" is selected in step S16 and no liquid storage unit is to be placed between the layer formed in the immediately preceding step S15 and the layer to be formed immediately thereafter, step S17 is skipped and the process proceeds to step S18. Steps S11 to S15 are then performed again to form the next layer. Furthermore, step S17 is either performed or skipped depending on the predetermined installation position of the liquid storage unit.

[0213] Steps S11 to S15 and step S17 are repeatedly executed until step S16 returns "Yes." That is, steps S11 to S15, together with step S17 which is executed as needed, are repeatedly executed the same number of times as the number of layers set in advance. This results in a laminated body including one or more liquid storage sections in a predetermined arrangement and including the predetermined number of layers stacked one on top of the other.

[0214] According to this laminate manufacturing method, it is possible to easily and reliably produce a laminate including a predetermined number of layers each having predetermined properties and a predetermined number of simulated blood vessels. In particular, since the method is configured to proceed to the formation process of the next layer after one layer is cured, it is possible to manufacture the desired laminate with high ease and high reliability.

[0215] When the laminate includes two or more layers, the same substrate may be used for all the layers, or two or more substrates may be used separately. By using the same substrate for all the layers, a laminate can be obtained in which all the layers have the same refractive index.

[0216] The same particles may be used for all layers, or two or more particles may be used separately.In addition, two or more layers having the same scattering properties may be formed consecutively and treated as a single layer.

[0217] Although the eye model of the exemplary embodiment described above includes a laminate including a substrate and a plurality of layers, the eye model of other exemplary embodiments may not include a plurality of layers. Some examples of such eye models are described below.

[0218] FIG. 18A is a top view of a pseudo fundus 800, which can be used as the fundus portion 570 of the model eye 500. The pseudo fundus 800 includes a substrate 810. On the substrate 810, a liquid storage section 830-m may have a configuration similar to that of the liquid storage section 630-m described above. The liquid storage section 830-m is fixed to the upper surface of the substrate 810 by fixing sections 840-1 and 840-2. The fixing sections 840-1 and 840-2 may be fixed in any manner, and may be bonded using an adhesive, for example. In this example, multiple layers are not provided on the substrate 810, but this is not limiting.

[0219] When the ophthalmologic apparatus 1 applies an OCTA scan to the pseudo fundus 800, the measurement light LS that passes through approximately the center of the objective lens 22 is projected onto the pseudo fundus 800. The ophthalmologic apparatus 1 detects the return light of the measurement light LS projected onto the pseudo fundus 800 to construct an OCTA image. Unlike the laminate 600 of the above-described embodiment, which has multiple layers 620-1, 620-2, ..., 620-N, the pseudo fundus 800 of this embodiment does not have refractive index matching, resulting in very strong specular reflection. Specular reflection also occurs on the surface of the liquid storage section 830-m (capillary). As described above, the measurement light LS is projected onto the pseudo fundus 800 from the front through the center of the objective lens, so OCTA is strongly affected by specular reflection. In other words, the return light of the measurement light LS contains a large specular reflection component. Under such conditions, it is difficult to properly grasp the state of Brownian motion within the liquid storage section 830-m. To solve this problem, in this embodiment, diffuse reflection is used to detect the state of Brownian motion in the liquid storage section 830-m, as will be explained below with further reference to Figure 18B.

[0220] 18A and 18B, the liquid storage section 830-m is disposed at a position away from the central region of the substrate 810. Reference numeral 850 denotes the range (observation range) to which scanning for OCTA is applied. Reference numeral 860 denotes the region onto which the measurement light LS that has passed through the center of the objective is projected. The projection region 860 of the measurement light LS is disposed in the central region of the substrate 810.

[0221] With this configuration, it is possible to detect the state of Brownian motion in the liquid storage unit 830-m by utilizing the diffuse reflection of the measurement light LS projected at a position away from the liquid storage unit 830-m, without projecting the measurement light LS directly onto the liquid storage unit 830-m. That is, the return light of the measurement light LS projected onto the projection area 860 includes the diffuse reflected light that has passed through the liquid storage unit 830-m, out of the diffuse reflected light at the projection area 860, and this embodiment can detect the state of Brownian motion in the liquid storage unit 830-m based on this diffuse reflected light.

[0222] In the pseudo fundus 800A shown in FIG. 18C, one or more liquid storage units 830A are provided in the central region of a substrate 810A. The liquid storage unit 830A is fixed to the upper surface of the substrate 810A by a fixing unit 840A. Reference numeral 850A denotes an observation area. When the pseudo fundus 800A is used to evaluate OCTA function, the projection area 860A of the measurement light LS overlaps with the liquid storage unit 830A. This causes strong specular reflection to be mixed into the return light of the measurement light LS, making it impossible to properly detect the state of Brownian motion within the liquid storage unit 830A. While this configuration can be adopted, it is preferable to additionally provide a means for preventing specular reflection. For example, it is possible to apply a coating to suppress specular reflection to the surface of the liquid storage unit 830A and / or the upper surface of the substrate 810, to provide an optical filter that attenuates or blocks specular reflection, or to apply a filter treatment that reduces or eliminates the specular reflection component of the return light.

[0223] FIG. 19 shows another embodiment of a pseudo fundus 900 in which a liquid container is disposed outside the projection area of ​​the measurement light LS. The pseudo fundus 900 includes a substrate 910. M liquid containers 930-1, 930-2, ..., 930-M are arranged on the substrate 910 to form an M-sided polygon (M is an integer equal to or greater than 1). The M liquid containers 930-1, 930-2, ..., 930-M are fixed to the upper surface of the substrate 910 by M fixing portions 940-1, 940-2, ..., 940-M. Each liquid container 930-m may have a configuration similar to that of the liquid container 630-m described above. Reference numeral 950 denotes the observation range. Reference numeral 960 denotes the projection area of ​​the measurement light LS. This embodiment also makes it possible to detect the state of Brownian motion within the liquid container 930-m by utilizing diffuse reflection without being affected by strong specular reflection.

[0224] <Characteristics, actions, effects> Some features, operations, and advantages of the exemplary embodiments disclosed above will be described.

[0225] The eye model (500) of some exemplary embodiments is used in the field of ophthalmology and includes a liquid storage section (630-m) that stores a liquid in which particles are suspended.

[0226] The eye model having such a configuration can detect the Brownian motion of particles suspended in the liquid stored in the liquid storage unit by OCTA. Therefore, the eye model of the exemplary embodiment can be used as a phantom for OCTA.

[0227] Furthermore, the eye model of the exemplary embodiment uses Brownian motion to generate OCTA signals, so no liquid flow generator is required to mimic blood flow. Therefore, the structure of the eye model of the exemplary embodiment is simple and compact. The liquid storage unit may have a shape that mimics a blood vessel, and may include, for example, a tubular body (640) that contains a liquid to which microparticles have been added.

[0228] In order to further improve the actions and effects of such exemplary embodiments and / or to obtain other actions and effects, various configurations and features described below can be optionally adopted.

[0229] The eye model (500) of some exemplary embodiments may include a plurality of liquid storage sections (630-1 to 630-M). In this case, the plurality of liquid storage sections (630-1 to 630-M) may store liquids of different viscosities. This configuration makes it possible to simulate a plurality of different blood flow conditions.

[0230] In some exemplary embodiments, the liquid storage units (630-1 to 630-M) may store liquids in which particles of different sizes are suspended. This configuration makes it possible to simulate a number of different blood flow conditions.

[0231] In some exemplary embodiments, at least one of the multiple liquid storage units (630-1 to 630-M) may be arranged at an angle with respect to the axial direction. This configuration allows the vascular distribution of the human fundus to be simulated. Furthermore, since it becomes possible to detect signal changes due to the Doppler effect caused by Brownian motion, it becomes possible to use the exemplary embodiment of the model eye as a phantom for evaluating the blood flow parameter measurement function.

[0232] In some exemplary embodiments, at least two of the liquid storage sections (630-1 to 630-M) may be arranged at different inclination angles relative to the axial direction. This configuration makes it possible to simulate a number of different blood flow conditions.

[0233] In some exemplary embodiments, the eye model 500 may further include a laminate 600 made up of multiple layers 620-1 to 620-N. Such an eye model has a structure similar to the human fundus, and therefore can be used as a phantom for OCT structural imaging in addition to being used as a phantom for OCTA.

[0234] The arrangement of the liquid storage unit (630-m) in the eye model (500) of the exemplary embodiment is arbitrary. For example, as shown in FIG. 10(A), the liquid storage unit may be arranged inside one of the multiple layers. Alternatively, as shown in FIG. 10(B), a liquid storage unit may be provided in each of at least two of the multiple layers. Alternatively, as shown in FIGS. 10(C) and 10(D), the liquid storage unit may be arranged across at least two of the multiple layers. These are presented as non-limiting examples that mimic the vascular distribution pattern in the human fundus.

[0235] In some exemplary embodiments, a portion of the liquid storage unit may be exposed from the laminate. In the example shown in FIG. 11, both ends of the liquid storage unit are exposed from the laminate, but this is not a limitation. For example, a configuration in which only one end of the liquid storage unit is exposed from the laminate, or a configuration in which the center of the liquid storage unit is exposed from the laminate, may be adopted. Generally, any portion of the liquid storage unit may be exposed from the laminate. With such a configuration, the liquid storage unit can be viewed from the outside, which facilitates the task of positioning the model eye relative to the ophthalmic device and the task of determining the area to which OCT scanning is to be applied.

[0236] In some exemplary embodiments, a configuration in which the orientation of the liquid container can be changed can be employed. In the example shown in FIG. 12, the liquid container is configured to be rotatable in a plane perpendicular to the stacking direction (axial direction) of the multiple layers of the laminate (a plane substantially corresponding to the xy plane when OCT scanning is performed by the ophthalmic apparatus 1), but the manner in which the orientation of the liquid container can be changed is not limited to this. For example, the plane to which the rotational orbit of the liquid container belongs is not limited to the xy plane, and may be any plane. Furthermore, the rotation direction of the liquid container is not limited to a single direction, and may be rotation in any two of the xy plane, the yz plane, and the zx plane, for example.

[0237] Some exemplary embodiments of the eye model (500) may further include a first temperature control unit (470) for maintaining a constant temperature of the liquid in the liquid storage unit (630-m). This configuration stabilizes the Brownian motion of particles suspended in the liquid, thereby stabilizing the performance of the phantom. This improves the accuracy, precision, and reproducibility of the OCTA performance evaluation. While the temperature control unit 470 in the example shown in FIG. 14 is depicted as a separate element from the eye model (500), at least a portion of the first temperature control unit (470) may be incorporated into the eye model (500), attached to the eye model (500), or connected to the eye model (500) via a wire or wirelessly.

[0238] In some exemplary embodiments, the model eye (500) may further include a second temperature control unit (470) for changing the temperature of the liquid in the liquid storage unit (630-m). This configuration allows the Brownian motion of particles suspended in the liquid to be adjusted to achieve the desired phantom behavior. While the temperature control unit 470 in the example shown in FIG. 14 is depicted as a separate element from the model eye (500), at least a portion of the second temperature control unit (470) may be incorporated into the model eye (500), attached to the model eye (500), or connected to the model eye (500) via a wire or wirelessly.

[0239] The model eye (500) according to the exemplary embodiment may include a laminate (570; 600) according to any of the exemplary embodiments and a lens (510, 550) capable of forming a focus on the laminate.

[0240] Any of the features disclosed in the above exemplary embodiments can be combined with the eye model of the exemplary embodiment.

[0241] An ophthalmic device (1) according to an exemplary embodiment includes a data acquisition unit and an eye model. The data acquisition unit (2, 100, 210, 220; 410) has a configuration for optically acquiring data of the eye. The eye model (500) is used for evaluating the data acquisition unit. The eye model includes a liquid storage unit (630-m) that stores a liquid in which fine particles are suspended.

[0242] By using an ophthalmic device equipped with a model eye of this configuration, it is possible to evaluate the performance of the OCTA function of this ophthalmic device by utilizing the Brownian motion of particles floating in the liquid stored in the liquid storage unit.

[0243] The ophthalmic apparatus (1) of some exemplary embodiments may further include an evaluation unit (440). The evaluation unit is configured to generate evaluation information based on data acquired from the eye model by the data acquisition unit.

[0244] According to this aspect, the ophthalmologic apparatus can perform performance evaluation by itself, which makes it easy to adjust and calibrate the apparatus after installation in a medical institution, for example. Furthermore, by configuring the apparatus to automatically perform periodic quality evaluation and send the evaluation results to a maintenance server, it becomes possible to provide a remote maintenance service. The methods for using the evaluation results are not limited to these.

[0245] In some exemplary embodiments of the ophthalmic device (1), the data acquisition unit may include an optical system (2, 100; 410). The ophthalmic device may further include an alignment system (420, 420A, 420B). The alignment system is configured to align the optical system with a model eye (500) placed in a predetermined position. In addition, the evaluation unit (440) may be configured to generate evaluation information based on data acquired from the model eye by the data acquisition unit after alignment.

[0246] According to this aspect, it is possible to facilitate the evaluation of an ophthalmic device using an eye model. That is, in order to properly perform an evaluation using an eye model, it is necessary to accurately position the eye model relative to the optical system of the ophthalmic device to be evaluated. However, with the ophthalmic device of this aspect, the cumbersome task of manually adjusting the position of the eye model is not required.

[0247] Furthermore, according to this aspect, the ophthalmic device can be evaluated with the model eye placed in a suitable alignment state. Therefore, the ophthalmic device can be appropriately evaluated. For example, according to this aspect, it is possible to improve the accuracy, precision, and reproducibility of the evaluation of the ophthalmic device.

[0248] Furthermore, according to this aspect, it is possible to evaluate not only the imaging performance and measurement performance of the ophthalmic apparatus, but also the alignment performance.

[0249] In some exemplary embodiments of the ophthalmic device (1), the data acquisition unit (2, 100, 210, 220; 410) can acquire data from a specific portion of the eye model (500) at least twice. Furthermore, the evaluation unit (440) can generate evaluation information based on two or more pieces of data acquired from the specific portion of the eye model by the data acquisition unit. By employing this configuration, the performance of the OCTA function can be evaluated by the ophthalmic device itself.

[0250] Any of the features disclosed in the above exemplary embodiments can be combined with the ophthalmic apparatus of the exemplary embodiment.

[0251] The above disclosure is merely an example of how to implement the present invention. Those who intend to implement the present invention can make any modifications (omissions, substitutions, additions, etc.) within the scope of the gist of the present invention. [Explanation of symbols]

[0252] 1 Ophthalmology equipment 500 model eyes 630-m (m = 1, ..., M; M is an integer of 1 or more) Liquid storage section

Claims

1. A model eye used in the field of ophthalmology, a plurality of liquid storage sections in which liquid in which particles undergoing Brownian motion are suspended is sealed and stored; The plurality of liquid storage sections store liquids having different viscosities. Model eyes.

2. The liquids in which the particles of different sizes are suspended are stored in the plurality of liquid storage units. The eye model of claim 1.

3. a data acquisition unit that acquires eye data using optical coherence tomography angiography; an eye model to which optical coherence tomography angiography is applied for evaluation of the data acquisition unit; An ophthalmic device comprising: The model eye includes a liquid storage section in which a liquid in which particles exhibiting Brownian motion are suspended is sealed and stored, the data acquisition unit applies optical coherence tomography angiography to the eye model to generate a pseudo-vascular image that is an image representing a change in light scattering caused by the particles exhibiting Brownian motion; further including an evaluation unit that generates evaluation information based on the pseudo blood vessel image. Ophthalmology equipment.

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