Ophthalmic device

Abstract

To provide a schematic eye suitable as a phantom for OCT angiography (OCTA).SOLUTION: A schematic eye is used in an ophthalmology field and has a structure imitating an eye. The schematic eye includes a plurality of liquid storage parts storing liquid with floating particles. At least one of the plurality of liquid storage parts is disposed at an angle to an axial direction, the direction corresponding to an eye axis.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] This invention relates to 、 eye ophthalmic devices.

Background Art

[0002] In ophthalmic examinations, various imaging modalities are used. A typical example is optical coherence tomography (OCT). OCT is used not only for structural imaging but also for functional imaging.

[0003] For example, OCT angiography (OCT-Angiography; OCTA) is a functional imaging modality for depicting blood flow and is used to obtain retinal vascular images and choroidal vascular images (see, for example, Patent Document 1). OCTA is a technique that focuses on the fact that signals from the fundus tissue (structure) do not change over time, while signals from blood flow inside blood vessels change over time. By emphasizing the part where such temporal changes exist (blood flow signal), a vascular image is constructed. OCTA is also called OCT motion contrast imaging, etc. The image constructed by OCTA is called an angiography image, an angiogram, a motion contrast image, etc.

[0004] An ophthalmic device capable of performing OCTA is an extremely precise optical instrument, and in order to fully exhibit its performance, adjustment and calibration based on strict evaluation are necessary. There are various methods for evaluating ophthalmic devices, but the method of using a model eye as a phantom is widely used (see, for example, Patent Documents 2 and 3, and Non-Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Document

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

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

[0008] In addition, although it is conceivable to construct a phantom system that mimics blood flow by flowing a liquid, there are problems such as the need for a device that generates a liquid flow, the complication of the structure of the model eye and the system, and the enlargement of the system.

[0009] One object of this invention is to provide an ophthalmic device provided with a model suitable as a phantom for OCTA. the eye

Means for Solving the Problems

[0010] Some exemplary embodiments are model eyes used in the field of ophthalmology, including a liquid storage unit in which a liquid in which fine particles are suspended is stored.

[0011] The model eyes of some exemplary embodiments include a plurality of the liquid storage units.

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

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

[0014] In some exemplary embodiments, at least one of the plurality of liquid storage portions is arranged to be inclined with respect to the axial direction.

[0015] In some exemplary embodiments, at least two of the plurality of liquid storage portions are arranged at different inclination angles with respect to the axial direction.

[0016] In some exemplary embodiments, the liquid storage portion is arranged to be inclined with respect to the axial direction.

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

[0018] In some exemplary embodiments, the liquid storage portion is arranged inside any one of the plurality of layers.

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

[0020] In some exemplary embodiments, the liquid storage portion is arranged across at least two of the plurality of layers.

[0021] In some exemplary embodiments, a part of the liquid storage portion is exposed from the laminate.

[0022] In some exemplary embodiments, the orientation of the liquid storage portion can be changed.

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

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

[0025] In some exemplary embodiments, the liquid storage unit 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 eye data and a model eye for evaluating the data acquisition unit, wherein the model eye includes a liquid storage unit storing a liquid in which fine particles are suspended.

[0027] The ophthalmic device of some exemplary embodiments further includes an evaluation unit for generating evaluation information based on the data acquired from the model eye by the data acquisition unit.

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

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

Advantages 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 device including the same.

Brief Description of the Drawings

[0031]

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DETAILED DESCRIPTION OF THE INVENTION

[0032] Some exemplary embodiments of the model eye and the ophthalmic device according to the embodiment will be described. The ophthalmic device according to the exemplary embodiment includes the model eye according to the exemplary embodiment. Further, the performance of the ophthalmic device can be evaluated using the model eye according to the exemplary embodiment.

[0033] The ophthalmic device according to the exemplary embodiment described below is a composite device that combines an OCT device capable of performing OCTA with a fundus camera, but the ophthalmic device according to the exemplary embodiment is not limited thereto, and may be any ophthalmic device having an OCTA function. Some ophthalmic devices according to the exemplary embodiment have at least one of an alignment function and a performance evaluation function. Some ophthalmic devices according to the exemplary embodiment include a model eye for performance evaluation. On the other hand, some ophthalmic devices according to the exemplary embodiment do not include a model eye for performance evaluation.

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

[0035] Here, spectral domain OCT divides the light from a low-coherence light source into measurement light and reference light, overlaps the return light of the measurement light from the object to be examined with the reference light to generate interference light, detects the spectral distribution of this interference light with a spectroscope, and performs Fourier transform or the like on the detected spectral distribution to form an image.

[0036] On the other hand, swept source OCT divides the light from a wavelength-tunable light source into measurement light and reference light, overlaps the return light of the measurement light from the object to be examined with the reference light to generate interference light, detects this interference light with a photodetector such as a balanced photodiode, and performs Fourier transform or the like on the detection data collected according to the wavelength sweep and the scan of the measurement light to form an image.

[0037] Thus, spectral domain OCT is an OCT method that acquires a spectral distribution by spatial division, and swept source OCT is an OCT method that acquires a spectral distribution by time division. Note that other OCT methods such as time domain OCT may also be used.

[0038] In this specification, unless otherwise specified, "image data" and "image", which is visual information based on it, are not distinguished. Also, unless otherwise specified, the part or tissue of the eye to be examined and the corresponding part of the model eye are not distinguished. Further, unless otherwise specified, the part or tissue of the eye to be examined and its image are not distinguished, and the part of the model eye and its image are not distinguished.

[0039] <Configuration of Ophthalmic Apparatus> An exemplary ophthalmic device is shown in FIG. 1. The ophthalmic device 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The fundus camera unit 2 is provided with an optical system and mechanism for acquiring a frontal image of the eye to be examined 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 control unit 200 includes one or more processors configured to execute various processes (arithmetic operations, control, etc.). Further, the ophthalmic device 1 includes two anterior segment cameras 300 for photographing the anterior segment 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 holding portion 450 shown in FIGS. 4A and 4B. The base 310 houses a drive mechanism and an arithmetic control circuit. The housing 320 provided on the base 310 houses an optical system. The objective lens 22 is housed in a lens housing portion 330 protruding from the front surface of the housing 320.

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

[0042] As shown in FIG. 1, the anterior segment OCT attachment 400 can be disposed between the objective lens 22 and the eye to be examined E. When the anterior segment OCT attachment 400 is disposed in the optical path, the ophthalmic device 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 device 1 can apply an OCT scan to the posterior segment. The movement of the anterior segment OCT attachment 400 is performed manually or automatically.

[0043] In some embodiments, an OCT scan may be applicable to the posterior eye segment when the attachment is disposed in the optical path, and an OCT scan may be applicable to the anterior eye segment when the attachment is retracted from the optical path. Further, the measurement sites switchable by the attachment are not limited to the posterior eye segment and the anterior eye segment, and may be any site of the eye. Note that the configuration for switching the site to which the OCT scan is applied is not limited to such an attachment, and for example, a configuration including a lens movable along the optical path or a configuration including a lens insertable / removable with respect to the optical path may be adopted.

[0044] At least a part of the functions of the elements disclosed in this specification is implemented using circuitry or processing circuitry. The circuitry or processing circuitry includes a general-purpose processor, a dedicated processor, an integrated circuit, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (e.g., SPLD (Simple Programmable Logic Device), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array)), a conventional circuitry, and any combination thereof, which is configured and / or programmed to execute at least a part of the disclosed functions. A processor is regarded as a processing circuitry or circuitry that includes transistors and / or other circuitry. In the present disclosure, terms such as circuitry, unit, means, or the like refer to hardware that executes at least a part of the disclosed functions, or hardware that is programmed to execute at least a part of the disclosed functions. The hardware may be the hardware disclosed in this specification, or may be known hardware that is programmed and / or configured to execute at least a part of the described functions. When the hardware is a processor that can be regarded as a certain type of circuitry, the terms such as circuitry, unit, means, or the like refer to a combination of hardware and software, and this 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 eye segment) of the eye E to be examined. The digital image of the fundus Ef obtained (referred to as a fundus image, fundus photograph, etc.) is generally a frontal image such as an observation image or a photographed image. The observation image is obtained by video shooting using near-infrared light. The photographed image is a still image using flash light in the visible region.

[0046] The fundus camera unit 2 includes an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the eye E to be examined with illumination light. The photographing optical system 30 detects the return light of the illumination light irradiated to the eye E to be examined. The measurement light from the OCT unit 100 is guided to the eye E to be examined through the optical path in the fundus camera unit 2. The return light of the measurement light projected onto the eye E to be examined (for example, the fundus Ef) is guided to the OCT unit 100 through the same optical path in the fundus camera unit 2.

[0047] The light (observation illumination light) output from the observation light source 11 of the illumination optical system 10 is reflected by the concave mirror 12, passes through the condenser lens 13, and becomes near-infrared light after passing through the visible cut filter 14. Further, the observation illumination light is once focused near the imaging light source 15, reflected by the mirror 16, and guided to the aperture mirror 21 via the relay lens system 17, relay lens 18, aperture 19, and relay lens system 20. Then, the observation illumination light is reflected at the peripheral portion of the aperture mirror 21 (the region around the aperture portion), passes through the dichroic mirror 46, and is refracted by the objective lens 22 to illuminate the eye to be examined E (fundus Ef). The return light of the observation illumination light from the eye to be examined E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the aperture portion formed in the central region of the aperture mirror 21, passes through the dichroic mirror 55, passes through the imaging focusing lens 31, and is reflected by the mirror 32. Further, this return light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the image sensor 35 by the imaging lens 34. The image sensor 35 detects the return light at a predetermined frame rate. Note that the focus of the imaging optical system 30 can be adjusted to match the fundus Ef or its vicinity, and can also be adjusted to match the anterior eye segment or its vicinity.

[0048] The light (imaging illumination light) output from the imaging light source 15 is irradiated onto the fundus Ef through the same path as the observation illumination light. The return light of the imaging illumination light from the eye to be examined E is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by the mirror 36, and is imaged on the light receiving surface of the image sensor 38 by the imaging lens 37.

[0049] The liquid crystal display (LCD) 39 displays a fixation target (fixation target image). A part of the light beam output from the LCD 39 is reflected by the half mirror 33A, then reflected by the mirror 32, passes through the aperture of the aperture mirror 21 via the photographing focusing lens 31 and the dichroic mirror 55. The light beam that has passed through the aperture of 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 for guiding and fixing the line of sight. The direction in which the line of sight of the eye to be examined E is guided (and fixed), that is, the direction in which fixation of the eye to be examined E is promoted, 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 the fixation position include a fixation position for obtaining an image centered on the macula, a fixation position for obtaining an image centered on the optic nerve head, a fixation position for obtaining an image centered on a position between the macula and the optic nerve head (fundus center), and a fixation position for obtaining an image of a site far from the macula (peripheral fundus).

[0051] A graphical user interface (GUI) or the like for specifying at least one of such typical fixation positions can be provided. Also, a GUI or the like for manually moving the fixation position (display position of the fixation target) can be provided. 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 eye to be examined 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 parts (light emitting diodes or the like) are arranged in a matrix can be adopted instead of the display device. In this case, by selectively lighting the plurality of light emitting parts, the fixation position of the eye to be examined E by the fixation target can be changed. As another example, a device provided with one or more movable light emitting parts can generate a fixation target with a changeable fixation position.

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

[0054] Note that the alignment method applicable to the exemplary embodiment is not limited to the one using such an alignment index, and may be any known method such as a method using the anterior eye camera 300, a method using a corneal reflection image (Purkinje image) formed by projecting a light beam onto the cornea from the front, or a method using a skiascope that projects a light beam obliquely onto the cornea and detects the corneal reflected light in the opposite direction.

[0055] The focusing optical system 60 generates a split index used for focus adjustment with respect to the eye E to be examined. In conjunction with the movement of the imaging focusing lens 31 along the optical path of the imaging optical system 30 (imaging optical path), the focusing optical system 60 is moved along the optical path of the illumination optical system 10 (illumination optical path). 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 inclined with respect to the illumination optical path. The focus light output from the LED 61 passes through the relay lens 62, is separated into two light beams by the split index plate 63, passes through the two-hole diaphragm 64, is reflected by the mirror 65, is once imaged on the reflecting surface of the reflecting rod 67 by the condenser lens 66, and is then reflected. Further, the focus light passes through the relay lens 20, is reflected by the aperture mirror 21, passes through the dichroic mirror 46, and is projected onto the eye E to be examined through the objective lens 22. The return light (such as fundus reflex light) of the focus light from the eye E to be examined is guided to the image sensor 35 through the same path as the return light of the alignment light. Manual focusing and autofocusing can be executed based on the received light image (split index image).

[0056] The diopter correction lenses 70 and 71 can be selectively inserted into the imaging 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 strong hyperopia. The diopter correction lens 71 is a minus lens (concave lens) for correcting strong 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. In the measurement arm, 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 are provided in order from the OCT unit 100 side.

[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. The change in the measurement arm length is used, for example, for optical path length correction according to the axial length of the eye or adjustment of the interference state.

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

[0060] The OCT focusing lens 43 is moved along the measurement arm to perform focus adjustment of the measurement arm. Note that the movement of the imaging focusing lens 31, the movement of the focusing 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 to the pupil of the eye to be examined 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 the ±x direction and a one-dimensional scanner (y-scanner) for deflecting the measurement light in the ±y direction. In this case, for example, either one of these one-dimensional scanners is disposed at a position optically conjugate to the pupil, or a position optically conjugate to 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 the light from a low coherence light source (broadband light source) into measurement light and reference light, overlaps the return light of the measurement light projected onto the eye to be examined E and the reference light that has passed through the reference optical path to generate interference light. The spectral distribution of the interference light generated by the interference optical system is detected by a spectroscope. The data (detection signal) obtained by detecting the spectral distribution of the interference light is sent to the arithmetic 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 (about 800 nanometers to 900 nanometers) and has a temporal coherence length of about several tens of micrometers. Note that the low-coherence light L0 may be near-infrared light having a wavelength band that is not visible to the human eye, for example, having a central wavelength of about 1040 to 1060 nanometers. The light source unit 101 includes an optical output device such as a superluminescent diode (SLD), an LED, or a semiconductor optical amplifier (SOA).

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

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

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

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

[0068] On the other hand, the measurement light LS generated by the fiber coupler 105 is guided to the collimator lens unit 40 through the optical fiber 127 and is converted into a parallel light 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, and is refracted by the objective lens 22 and projected onto the eye to be examined E. The measurement light LS is scattered and reflected at various depth positions of the eye to be examined E. The return light of the measurement light LS from the eye to be examined E travels in the reverse direction of the measurement arm, is guided to the fiber coupler 105, and reaches the fiber coupler 122 through the optical fiber 128.

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

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

[0071] When swept source OCT is adopted, the interference light generated by superimposing the measurement light and the reference light is branched at a predetermined branching ratio (for example, 1:1) to generate a pair of interference lights, and the generated pair of interference lights is guided to a photodetector. The photodetector includes, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that respectively detect a pair of interference lights, and outputs the difference between the pair of detection signals obtained thereby. The photodetector sends this output (detection signal such as a differential signal) to a data acquisition system (DAQ). A clock is supplied from the light source unit to the data acquisition system. 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 a wavelength tunable light source. The light source unit, for example, branches the light of each output wavelength to generate two branched lights, optically delays one of these branched lights, synthesizes these branched lights, detects the obtained synthesized light, and generates a clock based on the detection signal. The data acquisition system performs sampling of 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] In the ophthalmic apparatus 1 shown in FIGS. 1 and 2, both an element (for example, retroreflector 41) for changing the measurement arm length and an element (for example, retroreflector 114 or reference mirror) for changing the reference arm length are provided, but in some exemplary embodiments, only one of these elements is provided. By relatively changing the measurement arm length and the reference arm length (that is, by changing the optical path length difference between the measurement arm and the reference arm), the coherence gate position is changed. 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] <Operation and Control Unit 200> The arithmetic control unit 200 controls each part of the ophthalmic apparatus 1. Also, the arithmetic control unit 200 executes various arithmetic operations. For example, the arithmetic control unit 200 forms a reflection intensity profile for each A-line by subjecting the spectral distribution acquired by the spectroscope 130 to signal processing such as Fourier transform. Further, the arithmetic control unit 200 forms image data by imaging the reflection intensity profile of each A-line. The arithmetic processing therefor is the same as 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, and the like. Various computer programs are stored in a storage device such as a hard disk drive. The arithmetic control unit 200 may include an operation device, an input device, a display device, and the like.

[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 in which a display function and an operation function are integrated, such as a touch panel. The 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 eye to be examined 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 deviated from 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 reference numeral 300, and both of them may be collectively denoted by reference numeral 300. Further, the anterior eye camera that can be adopted instead of the anterior eye cameras 300A and 300B may be denoted by reference numeral 300.

[0077] In this embodiment, two anterior eye cameras 300A and 300B are provided, but the number of the anterior eye cameras 300 may be any number of one or more. Considering the arithmetic processing described later, a configuration capable of capturing images of the anterior eye from two different directions is sufficient (however, it is not limited thereto). Alternatively, a movable anterior eye camera 300 may be provided, and anterior eye imaging may be sequentially performed from two or more different positions from each other.

[0078] In this embodiment, two anterior eye cameras 300 are provided separately from the illumination optical system 10 and the imaging optical system 30. However, for example, the imaging optical system 30 can be used to capture images of the anterior eye. That is, one of the two or more anterior eye cameras 300 may be the imaging optical system 30. The anterior eye camera 300 according to this embodiment only needs to be capable of capturing images of the anterior eye from two (or more) different directions from each other.

[0079] A configuration for illuminating the anterior eye may be provided. This anterior eye illumination means includes, for example, one or more light sources. Typically, at least one light source (for example, an infrared light source) can be provided in the vicinity of each of the two or more anterior eye cameras 300.

[0080] Typically, anterior eye segment imaging from two or more different directions is performed substantially simultaneously. "Substantially simultaneously" means that in addition to the case where the timing of anterior eye segment imaging from two or more different directions is simultaneous, for example, a timing difference that can ignore eye movement is also allowed. By such substantially simultaneous imaging, it is possible to image the anterior eye segment from two or more different directions when the eye to be examined E is substantially in the same position and orientation.

[0081] Anterior eye segment imaging from two or more different directions may be video imaging or still image imaging. In the case of video imaging, for example, by controlling so as to match the imaging start timing by two or more anterior eye segment cameras 300, or by controlling the frame rate and the acquisition timing of each frame, substantially simultaneous anterior eye segment imaging as described above can be realized. On the other hand, in the case of still image imaging, for example, by controlling so as to match the imaging timing by two or more anterior eye segment cameras 300, substantially simultaneous anterior eye segment imaging can be realized.

[0082] Note that when imaging a model eye as described later, it is not necessary to perform such substantially simultaneous imaging.

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

[0084] <Control Unit 210> The control unit 210 includes a processor and controls each part of the ophthalmic 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 of the ophthalmic apparatus 1 (including the elements shown in FIGS. 1 to 3B). The main control unit 211 is realized, for example, by the cooperation of hardware including a circuit and control software.

[0086] The photographing focusing lens 31 disposed in the photographing optical path and the focus optical system 60 disposed in the illumination optical path are moved integrally or in association with each other by a photographing focusing drive unit (not shown) under the control of the main control unit 211. The retroreflector 41 provided on the measurement arm is moved by a retroreflector (RR) drive unit 41A under the control of the main control unit 211. The OCT focusing lens 43 disposed on the measurement arm is moved by an OCT focusing drive unit 43A under the control of the main control unit 211. Note that the movement of the OCT focusing lens 43 can be performed in association with the movements of the photographing focusing lens 31 and the focus optical system 60. The retroreflector 114 disposed on the reference arm is moved by a retroreflector (RR) drive unit 114A under the control of the main control unit 211. Each of the mechanisms exemplified here typically includes an actuator such as a pulse motor that operates under the control of the main control unit 211. The optical scanner 44 provided on the measurement arm operates under the control of the main control unit 211. Further, the main control unit 211 can control any element included in the ophthalmic device 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. Also, the main control unit 211 may be capable of controlling any peripheral device (apparatus, device, device, etc.) connected to the ophthalmic device 1 and any apparatus, device, device, etc. accessible by the ophthalmic device 1.

[0087] The movement mechanism 150 moves, for example, at least the fundus camera unit 2 three-dimensionally. In a typical example, the movement mechanism 150 includes an x-stage movable in the ±x direction (left-right direction), an x movement mechanism for moving the x-stage, a y-stage movable in the ±y direction (up-down direction), a y movement mechanism for moving the y-stage, a z-stage movable in the ±z direction (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 control unit 211.

[0088] 〈Memory unit 212〉 The memory unit 212 stores various types of data. Examples of the data stored in the memory unit 212 include, for example, OCT image data, fundus image data, and subject eye information. The subject eye information includes subject information such as patient ID and name, left eye / right eye identification information, and electronic medical record information.

[0089] 〈Imaging unit 220〉 The imaging unit 220 forms OCT image data based on the data acquired by the spectrometer 130. The imaging unit 220 includes a processor. The imaging unit 220 is realized, for example, by the cooperation of hardware including a circuit and imaging software.

[0090] The imaging unit 220 forms cross-sectional image data based on the data acquired by the spectrometer 130. This imaging 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 imaging 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 profiles in a plurality of A-lines (scan lines along the z-direction) arranged in the area to which the OCT scan is applied.

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

[0093] The image forming unit 220 can process 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. Examples of rendering techniques include volume rendering, maximum intensity projection (MIP), minimum intensity projection (MinIP), surface rendering, multi-planar reformation (MPR), and the like. Further, the image forming unit 220 can project the three-dimensional image data in the z direction (A-line direction, depth direction) to construct projection data. Further, the image forming unit 220 can project a part of the three-dimensional image data (three-dimensional partial image data) in the z direction to construct a shadowgram. Note that the three-dimensional partial image data is set, for example, by applying segmentation to the three-dimensional image data.

[0094] As described above, the ophthalmic apparatus 1 of the present aspect can execute OCTA. When executing OCTA, the ophthalmic 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 the data set collected by this repeated scan. This motion contrast image is an angiography image that emphasizes and images the temporal change of the interference signal caused by the blood flow in the fundus Ef. Typically, OCTA is applied to a three-dimensional region of the fundus Ef, and image data (three-dimensional angiography image data) representing the three-dimensional distribution of the blood vessels in the fundus Ef is obtained.

[0095] The image forming unit 220 can construct arbitrary two-dimensional angiography image data and / or arbitrary pseudo three-dimensional angiography image data from this three-dimensional angiography image data. For example, the image forming unit 220 can apply multi-planar reformation to the three-dimensional angiography image data to construct two-dimensional angiography image data representing an arbitrary cross-section of the fundus Ef. Further, the image forming unit 200 can apply segmentation to the three-dimensional angiography image data and construct frontal image data from an image region (slab) corresponding to a predetermined tissue specified thereby. Typically, frontal image data is constructed for various depth areas such as the superficial retina, deep retina, and choroid.

[0096] <Data processing unit 230> The data processing unit 230 performs various data processes. For example, the data processing unit 230 can apply image processing and analysis processing to OCT image data, or apply image processing and analysis processing to observation image data or captured image data. The data processing unit 230 includes a processor. The data processing unit 230 is realized, for example, by the cooperation of hardware including a circuit and data processing software.

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

[0098] <Model eye 500> The model eye 500 is a model eye according to an exemplary embodiment, and is attached to the face holding unit 450 via the attachment 460 for performance evaluation of the ophthalmic device 1. In this embodiment, the model eye 500 is arranged at the same position as the eye to be examined E. Thereby, the alignment of the data acquisition optical system 410 with respect to the model eye 500 (alignment) can be performed using the alignment function of the ophthalmic device 1 to facilitate the evaluation work. Furthermore, 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 can be evaluated.

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

[0100] The iris part 520 forms an aperture 540 corresponding to the pupil. Further, the iris part 520 may be provided with a variable part 530 for changing the size (aperture diameter) of the aperture 540. The variable part 530 is, for example, detachable from the iris part 520, and a plurality of members corresponding to different aperture diameters are selectively applied. Alternatively, the variable part 530 is configured to be movable with respect to the iris part 520. Note that the size of the aperture 540 may be fixed. The vitreous body part 560 is filled with a liquid such as oil, for example. Note that the substance filled in the vitreous body part 560 is arbitrary and may be any of an arbitrary gas, an arbitrary liquid, and an arbitrary solid, for example. Typically, a gas (air) exists in the space between the cornea part 510 and the lens part 550. Note that the substance provided in the space between the cornea part 510 and the lens part 550 is arbitrary and may be any of an arbitrary gas, an arbitrary liquid, and an arbitrary solid, for example.

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

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

[0103] The distance between the central position of the front surface of the corneal part 510 (the position corresponding to the corneal apex) and the front surface of the fundus part 570 may be designed based on the axial length of the human eye. Also, the focal length of the entire corneal part 510, lens part 550, and vitreous part 560 may be designed to have a value equivalent to that of the human eye. For example, it may have means (such as a spacer) for changing the optical distance between the lens part 550 and the fundus part 570. Thereby, it becomes possible to change the refractive power of the model eye 500, and for example, it becomes possible to evaluate imaging and measurement for an eye with a long axial length.

[0104] The reflectance of the front surface (the surface on the corneal part 510 side) of the iris part 520 (variable part 530) may be designed to be equal to that of the human eye. This reflectance may be, for example, the reflectance at an infrared wavelength. Similarly, for the front surface of the corneal part 510, etc., it is possible to design it to have the same reflectance as that of the human eye. Also, the model eye 500 may be designed such that the entrance pupil of the iris part 520 (variable part 530, aperture 540) is arranged at the same position as the entrance pupil of the human iris.

[0105] In order to prevent light used by the data acquisition optical system 410 (measurement light LS in this embodiment) or light used by the alignment system 420 (wavelength band detected by the anterior eye camera 300 (e.g., infrared wavelength) in this embodiment) from undergoing multiple reflections within the model eye 500, it is possible to provide an antireflection film on a lens or the like, or apply an antireflection paint to an internal member.

[0106] When performing alignment using two or more anterior eye cameras 300 (cameras having sensitivity to infrared wavelength) as in the ophthalmic apparatus 1 of this embodiment, for example, the following parameter values can be set. First, the entrance pupil of the aperture 540 may be disposed at a position approximately 3.06 millimeters away from the corneal portion 510. Also, the diameter of the aperture 540 may be set to a value within the range of 2 to 10 millimeters. Further, the infrared light reflectance of the iris portion 520 (variable portion 530) may be set to a value within the range of 2.0 to 2.5 percent. With such a design, it becomes possible to perform alignment of the model eye 500 with respect to the aperture 540 in the same manner as when performing alignment based on the pupil of the human eye.

[0107] Even when other alignment methods are used, the parameter values of the model eye 500 are set according to the method. For example, when performing alignment using a corneal reflection image (Purkinje image), the radius of curvature of the corneal portion 510 (radius of curvature of the front surface of the corneal equivalent lens) may be set to approximately 7.7 millimeters. Similarly, when performing alignment using a light lever, the radius of curvature of the corneal portion 510 (radius of curvature of the front surface of the corneal equivalent lens) can be set to approximately 7.7 millimeters.

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

[0109] FIG. 6A is a side view of a laminate 600 in an exemplary embodiment, and FIG. 6B is a top view of the laminate 600. The laminate 600 includes a plurality of layers 620-1, 620-2, ···, 620-N. Here, N is an integer of 2 or more. Any one of the plurality of layers 620-1, 620-2, ···, 620-N may be represented by 620-n (n = 1, 2, ···, N). The plurality of layers 620-1, 620-2, ···, 620-N have, for example, different scattering characteristics from each other.

[0110] The shape of the layer 620-n is arbitrary and may be formed, for example, in a flat plate shape or a curved plate shape. Also, two adjacent layers 620-n and 620-(n + 1) (n = 1, ···, N-1) among the plurality of layers 620-1, 620-2, ···, 620-N are formed such that one layer is formed after the other layer is cured. Thereby, the material of the layer 620-n and the material of the layer 620-(n + 1) do not mix with each other, and the intended characteristics of each layer are exhibited. An example of a method for manufacturing such a laminate will be described later.

[0111] The 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 lowermost layer 620-N among the plurality of layers 620-1, 620-2, ···, 620-N and the upper surface of the substrate 610 are directly or indirectly bonded. As an example of indirect bonding, an antireflection 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. As the material of the substrate 610, for example, at least one of silicon dioxide (SiO2), calcium fluoride (CaF2), aluminum oxide (Al2O3), magnesium fluoride (MgF2), zinc selenide (ZnSe), germanium (Ge), calcium carbonate (CaCO3), polymethyl methacrylate resin, polyimide resin, polyethylene resin, and polycarbonate resin can be adopted, but it is not limited thereto. In some exemplary embodiments, the laminate may or may not include a substrate.

[0113] The layer 620-n has characteristics (configuration, function, property) that simulate some tissues (layered tissue, membranous tissue) of the human fundus. For example, the layer 620-n has characteristics (configuration, function, property) corresponding 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 any two or more of these.

[0114] The layer 620-n is formed of at least a base material and fine particles dispersed in this base material. In some exemplary embodiments, the plurality of base materials in the plurality of layers 620-1, 620-2, ···, 620-N have (substantially) equal refractive indices to each other. This base material refractive index is determined according to the refractive index of the human fundus or the refractive index of one or more sub-tissues of the human fundus.

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

[0116] When the refractive index of the base material is determined according to the refractive index of one or more sub - tissues of the human fundus that is 1 or more, the refractive index of the base material may be, for example, the standard refractive index of a predetermined part (one or more sub - tissues) of the human fundus or a refractive index approximated thereto. Alternatively, the refractive index of the base material may be a refractive index (statistical value: average value, 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 approximated thereto. Alternatively, the refractive index of the base material may be the standard refractive index of a predetermined representative sub - tissue of the human fundus or a refractive index approximated thereto. The standard refractive index can be obtained, for example, from a standard model eye or clinical data. The one or more sub - tissues of the human fundus referred to for determining the refractive index of the base material 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 considered necessary to achieve a value of about 1.40 or less in order to realize a refractive index of the base material equivalent to that of the human fundus. Therefore, an organosilicon compound can be used as the material of the base material. Thereby, the refractive index of the base material can be reduced to about 1.41. Also, by adopting a fluorine compound as the material of the base material, the refractive index of the base material can be reduced to less than 1.40.

[0118] The characteristics considered in the design of the plurality of layers 620 - 1, 620 - 2, ···, 620 - N are not limited to refractive characteristics (refractive index). For example, any optical characteristics such as transmission characteristics (transmittance, transmittance degree), diffusion characteristics (diffusion rate, diffusion coefficient, diffusion degree) can be considered.

[0119] In addition, scattering characteristics (scattering degree, scattering intensity, scattering coefficient) are considered in the design of the plurality of layers 620-1, 620-2, ···, 620-N. As described above, the plurality of layers 620-1, 620-2, ···, 620-N have different scattering characteristics from each other. The scattering characteristics of the layer 620-n are designed, adjusted, and controlled according to any one or more of the characteristics of the layer, the characteristics of the base material, the characteristics of the fine particles, and the combined characteristics of the base material and the fine particles. In order to determine the scattering characteristics of the layer 620-n, for example, at least one of the type, size, and addition amount of the fine particles is referred to.

[0120] When the scattering characteristics of the layer 620-n are determined according to at least the addition amount of the fine particles, the addition amount of the fine particles can be set within a range of, for example, 0.001 wt% to 20 wt% as the weight percentage of the fine particles with respect to the base material, but is not limited thereto. In some exemplary embodiments, the addition amount of the fine particles may be set within a range of 0.04 wt% to 4 wt%.

[0121] When the thickness of the layer 620-n is referred to in order to determine the scattering characteristics of the layer 620-n, the layer thickness can be set within a range of 5 micrometers to 500 micrometers, but is not limited thereto. Also, the thickness of the laminate 600 may be within a range of, for example, 50 micrometers to 700 micrometers, but is not limited thereto.

[0122] In order to determine the scattering characteristics of the layer 620-n, 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 can be adopted as the material of the fine particles, but is not limited thereto.

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

[0124] To determine the scattering characteristics of layer 620-n, at least one of a true spherical shape, a spherical shape, a needle shape, and a star shape can be adopted as the shape of the fine particles, but is not limited thereto.

[0125] An example of the schematic configuration of two layers in the laminate thus configured is shown in FIG. 7. Layer 620-n1 in FIG. 7 corresponds to any one of the plurality of layers 620-1, 620-2, ···, 620-N in FIG. 6, and layer 620-n2 corresponds to another one of the layers. The refractive index of the base material 621-n1 of layer 620-n1 and the refractive index of the base material 621-n2 of layer 620-n2 are equal to each other. Also, the two layers 620-n1 and 620-n2 have different scattering characteristics from each other. For such control of the scattering characteristics, the fine particles 622-n1 in layer 620-n1 and the fine particles 622-n2 in layer 620-n2 are different from each other in at least both the dimensions and the addition amount.

[0126] As shown in FIGS. 6A and 6B, the laminate 600 of this example is provided with liquid storage portions 630-1, ···, 630-M. Here, M is an integer of 1 or more. Any one of the one or more liquid storage portions 630-1, ···, 630-M may be represented by 630-m (m = 1, ···, M). That is, the laminate 600 is provided with one or more liquid storage portions 630-1, ···, 630-M.

[0127] An example of a method for creating and an example of the configuration of the liquid storage unit 630 - m will be described with reference to FIG. 8. In this example, in the first step (A), a capillary (capillary tube, tubular body) 640 simulating the blood vessels of the fundus of the eye 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 thereto. Also, the inner diameter (diameter of the hollow region) of the capillary 640 may be, for example, in the range of 10 micrometers to 300 micrometers.

[0128] Also, although not shown in the figure, a liquid in which fine particles are suspended is prepared. The base of the liquid may be, for example, water or an aqueous system, alcohol or an alcohol system, or glycol or a glycol system, but is not limited thereto. The viscosity of the liquid may be, for example, in the range of 0.5 millipascal - seconds to 100 millipascal - seconds, but is not limited thereto. Also, 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 thereto. Also, the concentration of the fine particles added to the liquid may be in the range of 0.01 weight percent to 5.00 weight percent, but is not limited thereto.

[0129] In the next step (B), the liquid 641 in which fine 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 fine particles are suspended.

[0130] In the next step (C), both ends (openings) of the capillary 640 filled with the liquid 641 in which fine particles are suspended are closed. The method of closing the openings is arbitrary, and for example, welding is employed. The locations of both ends of the capillary 640 thus closed are indicated by reference numerals 642 and 643.

[0131] In the next step (D), a cover 644 covering the closed portion 642 at the first end of the capillary 640 and a cover 645 covering the closed portion 64 at the second end are attached.

[0132] In the last step (E), the gap between the closed portion 642 of the capillary 640 and the cover 644 is filled with an adhesive 646, and the gap between the closed portion 643 and the cover 645 is filled with an adhesive 647. By curing the adhesives 646 and 647, the liquid 641 in which fine particles are suspended is completely sealed inside the capillary 640. As a result, a liquid storage portion 630-m in which the liquid 641 in which fine particles are suspended is stored is obtained.

[0133] When a plurality of liquid storage portions 630-1, ···, 630-M (M is an integer of 2 or more) are provided, these liquid storage portions 630-1, ···, 630-M may have different characteristics (configurations, functions, properties). For example, the plurality of liquid storage portions 630-1, ···, 630-M may have different forms. Typically, the plurality of liquid storage portions 630-1, ···, 630-M may have different shapes and / or different dimensions (length, thickness, diameter, etc.). Also, the plurality of liquid storage portions 630-1, ···, 630-M may be formed of different materials.

[0134] The plurality of liquid storage portions 630-1, ···, 630-M may be configured such that the moving speeds of the fine particles floating in the stored liquid are different from each other. For this purpose, any parameter related to the liquid and / or any parameter related to the fine particles can be considered. The parameter to be considered may be any parameter that affects the Brownian motion of the fine particles in the liquid. For example, by adjusting any one of the parameters of the viscosity of the liquid, the temperature of the liquid, and the form (shape, dimensions) of the fine particles, the moving speed of the fine particles floating in the liquid can be controlled. That is, the plurality of liquid storage portions 630-1, ···, 630-M may store liquids having different viscosities, may store liquids having different temperatures, and may store liquids in which fine particles having different dimensions are floating.

[0135] For example, as shown in FIG. 9(A), the liquid storage unit 630-m may be arranged to be inclined with respect to a predetermined axial direction 650. The axial direction 650 may be defined by the model eye (laminated bodies 600A, 600B) and / or the evaluation method. For example, the axial direction 650 may be a direction corresponding to the eye axis in a model eye (laminated bodies 600A, 600B) having a structure imitating an eye. Alternatively, the axial direction 650 may be a direction in which a plurality of layers in this laminated body (600A, 600B) are laminated (that is, the thickness direction, the depth direction, etc. of the laminated body). Alternatively, the axial direction 650 may be an axial direction used in OCT (that is, the z direction, the A-scan direction, the measurement light incident direction, etc.). By inclining in this way, in addition to the presence or absence of blood flow, it becomes possible to acquire blood flow parameters (blood flow velocity, blood flow volume, etc.). That is, it becomes possible to evaluate the amount of Doppler shift caused by the direction of blood flow.

[0136] When a plurality of liquid storage units 630-1, ···, 630-M (M is an integer of 2 or more) are provided, at least one of these liquid storage units 630-1, ···, 630-M may be arranged to be inclined with respect to the axial direction 650. Further, 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 are 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 and the inclination angle of the liquid storage unit 630-m2 with respect to the axial direction 650 may be different from each other. Thereby, it becomes possible to obtain information representing the relationship between the inclination angle and the blood flow parameter. For example, it is possible to obtain blood flow parameters for each of different inclination angles and perform corresponding evaluations. Also, it is possible to obtain changes and sensitivities of blood flow parameters according to changes in the inclination angle and perform corresponding evaluations.

[0137] When a model eye including a laminate composed of a plurality of layers is adopted as in the model eye 500 of this example, the arrangement relationship between the plurality of layers and the liquid storage portion may be arbitrary. For example, as shown in FIG. 6A, a liquid storage portion may be arranged between layers. Further, as shown in FIG. 10(A), a liquid storage portion 630-m may be arranged inside any layer 620-n of the laminate. Further, as shown in FIG. 10(B), a liquid storage portion 630-m may be arranged inside the layer 620-n of the laminate, and a liquid storage portion 630-(m + 1) may be arranged inside the layer 620-(n + 1). Note that the number of layers provided with the liquid storage portion is arbitrary, and the two layers provided with the liquid storage portions respectively may or may not be adjacent to each other. As shown in FIG. 10(C), a single liquid storage portion 630-m may be arranged across two layers 620-n and 620-(n + 1) of the laminate. Note that the liquid storage portion may be arranged across three or more layers. Another example in the case where a single liquid storage portion 630-m is arranged across two layers 620-n and 620-(n + 1) is shown in FIG. 10(D). In this example, the liquid storage portion 630-m is arranged to be inclined with respect to a predetermined axial direction. These are some examples of model eyes that mimic the distribution of blood vessels in the fundus of the eye.

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

[0139] In some exemplary embodiments, it is possible to adopt a configuration in which a part of the liquid storage portion is exposed from the laminate. FIG. 11 is a top view of a laminate 600C having such a configuration. The central portion 630a of the 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 grasp the position of the liquid storage portion 630 by referring to the exposed both end portions 630b and 630c. Thereby, the range to which the OCT scan for performance evaluation is applied can be determined, or the orientation in which the model eye is arranged can be determined.

[0140] The embodiments that can be adopted to obtain the same effect are not limited to this. For example, marks indicating the position of the liquid storage part embedded in the laminate can be attached to the outer surface of the model eye, the outer surface of the fundus oculi, and the outer surface of the laminate. Alternatively, the laminate may be formed using a transparent material.

[0141] The orientation of the liquid storage part when performing an OCT scan for performance evaluation of the ophthalmic device 1 may be arbitrary. Also, one or more of the model eye, the fundus oculi, and the laminate can be configured to be movable and / or variable, or one or more of a part of the model eye, a part of the fundus oculi, and a part of the laminate can be configured to be movable and / or variable. For example, as shown in FIGS. 12(A) and 12(B), the laminate 600D can be configured to be rotatable about a predetermined axis, whereby the orientation of the liquid storage part 630D can be changed.

[0142] In some exemplary embodiments, a liquid having a high viscosity such that Brownian motion of the fine particles does not substantially occur may be enclosed in the capillary. In the evaluation of the OCTA function, the purpose is to acquire a signal (motion signal) representing the motion of the fine particles in the liquid. According to this embodiment, however, a signal (reference signal) for a state in which the motion of the fine particles is substantially zero can be acquired, and the motion signal can be analyzed using this reference signal. For example, the motion signal can be corrected using the reference signal as an offset. Also, noise removal of the motion signal can be performed by treating the reference signal as a signal representing internal noise generated from an element group (such as an optical system and a processing system) for OCTA. The reference signal can also be used for evaluation and calibration of a model eye for acquiring the motion signal (that is, a model eye including a capillary enclosing a liquid having a low viscosity in which Brownian motion of the fine particles occurs). For example, it is possible to refer to the difference (such as a difference or a ratio) between the reference signal and the motion signal in order to adjust parameters (such as temperature) of the model eye for acquiring the motion signal.

[0143] 〈Face holding part 450, Attachment 460〉 The face holding unit 450 is a member that holds the face of the subject in order to fix the position of the eye E to be examined. In general ophthalmic devices, a chin rest and a forehead rest are provided (see, for example, Japanese Patent Application Laid-Open No. 2010-200905 and Japanese Patent Application Laid-Open No. 2015-139527). The chin rest is where the subject's chin is placed. The forehead rest is where the subject's forehead is applied (abutted).

[0144] The attachment 460 is a member for attaching the model eye 500 to the ophthalmic device 1. Typically, the attachment 460 is interposed between the model eye 500 and the ophthalmic device 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 detachable from the attachment 460. For example, the model eye 500 is attached to the attachment 460, and the attachment 460 is attached to the face holding unit 450. In other words, the model eye 500 is indirectly attached to the ophthalmic device 1 via the attachment 460.

[0145] Note that the location of the ophthalmic device 1 where the model eye 500 (attachment 460) is attached is not limited to the face holding unit 450. For example, it is possible to adopt a configuration in which the model eye 500 is attached to the outer surface of the 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 performing performance evaluation 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 the light (for example, the measurement light LS) from the data acquisition optical system 410 is guided to the model eye 500 through 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 eye E to be examined. 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 eye E to be examined. For example, the ophthalmic apparatus 1 of this embodiment can apply an OCT scan to the model eye 500 to acquire data from the fundus 570. Further, 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 respect to the model eye 500 installed at a predetermined position.

[0148] In this embodiment, the alignment system 420 includes two anterior eye cameras 300, a processing unit 430, and a moving mechanism 150. As described above, the two anterior eye cameras 300 include image sensors having sensitivity to infrared wavelengths and are configured to photograph the model eye 500 installed at a predetermined position from two different directions. Further, the moving mechanism 150 is configured to move the data acquisition optical system 410.

[0149] 〈Processing unit 430〉 The processing unit 430 controls the moving mechanism 150 based on two or more images of the model eye 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 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 three-dimensional movement amount 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 amount. 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 amount (the movement amount in the x direction, the movement amount in the y direction, and the movement amount in the z direction).

[0153] For details of the processing executed by the processing unit 430, refer to a series of documents by the applicant of the present application regarding 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] Note that the ophthalmic apparatus 1 of this aspect may perform alignment of the data acquisition optical system 410 with respect to the model eye 500 using the alignment optical system 50. In this case, auto-alignment (described above) using an alignment index is applied to the model eye 500.

[0155] The ophthalmic apparatus in some exemplary aspects may be capable of performing XY alignment and / or Z alignment described in Japanese Patent Application Laid-Open No. 2018-164616 by the applicant of the present application. The XY alignment is an alignment method using a corneal reflection image (Purkinje image), and the Z alignment is an alignment method using a light lever.

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

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

[0158] The alignment system 420A includes a projection unit 421A, an imaging unit 422A, a processing unit 430A, and a moving mechanism 150.

[0159] The projection unit 421A projects a light beam onto the model eye 500. In particular, the projection unit 421A projects a 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. Thereby, a bright spot image (corneal reflection image, Purkinje image) is formed on the corneal part of the model eye 500.

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

[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 (such as edge detection) based on changes in luminance values.

[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 with respect to 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 so as to cancel this deviation (so that the corneal reflection image is arranged at the reference position). Thereby, the optical axis of the data acquisition optical system 410 can be guided to the vertex position of the corneal part of the model eye 500.

[0163] For details of the processing executed by the processing unit 430A, refer to, 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 method using an optical lever to the alignment of the data acquisition optical system 410 for the model eye 500, instead of the configuration shown in FIG. 3B, for example, the configuration shown in FIG. 13B can be adopted. In the configuration example shown in FIG. 13B, the alignment system 420 shown in FIG. 3B is replaced with an alignment system 420B. Among the elements shown in FIG. 13B, the elements similar to those in FIG. 3B are denoted by the same reference numerals, and the description of those elements will not be repeated unless otherwise specified.

[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 millimeters.

[0166] The alignment system 420B includes a projection unit 421B, a photographing unit 422B, a processing unit 430B, and a moving mechanism 150.

[0167] The projection unit 421B projects a light beam onto the model eye 500. In particular, the projection unit 421B projects a 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 corneal portion of the model eye 500 is reflected on the surface of the corneal portion.

[0168] The imaging unit 422B is arranged in a direction that is substantially symmetric with respect to the optical axis of the data acquisition optical system 410 and in a direction substantially opposite to the projection direction of the light beam by the projection unit 421B. Typically, the projection unit 421B and the imaging unit 422B are arranged at positions that are substantially symmetric with respect to each other with the optical axis of the data acquisition optical system 410 as a reference. The imaging unit 422B is typically a line sensor in which a plurality of light receiving elements are arranged one-dimensionally. Note that the imaging unit 422B may 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 reflected light (corneal reflected light) of the light beam emitted from the projection unit 421B by the corneal part is detected by the imaging unit 422B. When the corneal reflected light is not detected by the imaging unit 422B, the image obtained by the imaging unit 422B is an all-black image. On the other hand, when the corneal reflected light is detected by the imaging unit 422B, the image obtained by the imaging unit 422B includes a bright spot image. The image obtained by the imaging unit 422B is input to the processing unit 430B.

[0169] The processing unit 430B analyzes the image acquired by the imaging unit 422B to determine the presence or absence of a bright spot image. When there is no bright spot image, a predetermined control signal is sent to the moving mechanism 150. On the other hand, when there is a bright spot image, the processing unit 430B identifies the position of the bright spot image and obtains 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 plurality of light receiving elements of the imaging unit 422B, and obtains 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 this deviation (so that the corneal reflected light is detected by the light receiving element at the reference address). Thereby, the distance between the model eye 500 and the data acquisition optical system 410 can be induced to a predetermined operating distance (working distance).

[0171] For details of the processing executed by the processing unit 430B, refer to, 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, for example, by the main control unit 211 and the data processing unit 230.

[0172] <Evaluation unit 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, after the ophthalmic apparatus 1 aligns the data acquisition optical system 410 with respect to the model eye 500 by the alignment system 420, the data acquisition optical system 410 applies an OCT scan to the model eye 500. This OCT scan is typically a scan for OCTA and applies the scan a predetermined number of times to a specific part of the model eye 500.

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

[0174] When generating the data quality evaluation information, the evaluation unit 440 executes a predetermined data quality evaluation process. For example, as described above, when the fundus 570 of the model eye 500 has a layered structure corresponding to the fundus of a human eye, the ophthalmic apparatus 1 applies an OCT scan to the fundus 570 by 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 compares, for example, 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 the comparison between the image of the fundus 570 and the evaluation image.

[0175] In this aspect, the evaluation unit 440 is configured to perform quality evaluation of OCTA data. The ophthalmic apparatus 1 applies OCT scans a predetermined number of times to a region of the fundus oculi 570 including at least a part of at least one of the plurality of liquid storage units 630-1, ···, 630-M by the data acquisition optical system 410. For example, the ophthalmic apparatus 1 may repeatedly apply OCT scans to the entire fundus oculi 570. The image forming unit 220 constructs a motion contrast image from the data set collected by this repeated OCT scan. This motion contrast image is a simulated (pseudo) angiography image obtained by imaging while emphasizing the temporal change of the interference signal caused by the Brownian motion of the fine 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 arbitrary two-dimensional image data and / or arbitrary three-dimensional image data from this three-dimensional image data as described above. The evaluation unit 440 can generate quality evaluation information of OCTA data, for example, by comparing the constructed image (OCTA image) of the fundus oculi 570 with a predetermined evaluation image.

[0176] As another example of generating data quality evaluation information, the evaluation unit 440 can obtain the value of a predetermined evaluation parameter representing data quality by analyzing the data acquired by the data acquisition optical system 410. This evaluation parameter may be, for example, an image quality evaluation parameter such as contrast or signal-to-noise ratio. Further, the evaluation parameter may be, for example, a measurement quality evaluation parameter such as a measurement accuracy parameter or a measurement precision parameter.

[0177] When generating alignment quality evaluation information, the evaluation unit 440 performs a predetermined alignment quality evaluation process. For example, the evaluation unit 440 can evaluate the alignment quality based on the time taken for alignment, the processing content, and the result. Further, the evaluation unit 440 can also evaluate the alignment error with respect to the liquid storage unit 630-m as an 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 until a suitable alignment state (for example, a state where the alignment error is within a predetermined range) is reached. For example, the evaluation unit 440 can compare the alignment time with a predetermined threshold value, and evaluate it as "low quality" if the alignment time exceeds the threshold value, and evaluate it as "high quality" if the alignment time is below the threshold value. Alternatively, the evaluation unit 440 can be configured to determine which range among a plurality of predetermined ranges (high quality range, acceptable range, defective range) the alignment time belongs to, 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 the processing executed by the alignment system 420 (420A, 420B). For example, the evaluation unit 440 can generate alignment quality evaluation information based on the number of repetitions of the alignment operation executed 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 the image from the anterior eye camera 300. For example, the evaluation unit 440 can compare the number of repetitions of the alignment operation with a predetermined threshold value, and evaluate it as "low quality" if the number of repetitions exceeds the threshold value, and evaluate it as "high quality" if the number of repetitions is below the threshold value. Alternatively, the evaluation unit 440 can be configured to determine which range among a plurality of predetermined ranges (high quality range, acceptable range, defective range) the number of repetitions belongs to, and generate alignment quality evaluation information based on the range to which the number of repetitions belongs.

[0180] In some exemplary embodiments, the evaluation unit 440 can generate alignment quality evaluation information based on the results of the processes executed by the alignment system 420 (420A, 420B). For example, the evaluation unit 440 can obtain the alignment state (e.g., alignment error) reached by the alignment system 420 performing the alignment operation over a predetermined time, and can 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 value, and can evaluate as "low quality" when the alignment error exceeds the threshold value, and can evaluate as "high quality" when the alignment error is below the threshold value. Alternatively, the evaluation unit 440 may be configured to determine which range among a plurality of predetermined ranges (high quality range, acceptable range, defective range) the alignment error belongs to, and generate alignment quality evaluation information based on the range to which the alignment error belongs.

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

[0182] In a first aspect, the temperature control unit 470 is configured to keep the temperature of the liquid stored in the liquid storage unit 630-m constant. For example, the temperature control unit 470 in this aspect 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 warm air and / or cold air, the second means may be a thermistor or a thermocouple sensor, and the third means may be a processor. According to this aspect, since the temperature of the liquid stored in the liquid storage unit 630-m can be kept substantially constant, it is possible to stabilize the state of Brownian motion (such as the moving speed of the fine particles) of the fine particles floating in this liquid. Thereby, it is possible to improve the accuracy, precision, reproducibility, etc. of the performance evaluation of the ophthalmic apparatus 1.

[0183] In a second aspect, 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 in this aspect may be the same as that in the first aspect. According to this aspect, since the temperature of the liquid stored in the liquid storage unit 630-m can be changed to a desired temperature, it is possible to lead the state of Brownian motion (such as the moving speed of the fine particles) of the fine particles floating in this liquid to a desired state. Thereby, it is possible to improve the accuracy, precision, reproducibility, etc. of the performance evaluation of the ophthalmic apparatus 1.

[0184] <Operation> An example of the operation of the ophthalmic apparatus 1 according to this aspect will be described. An example of the operation of the ophthalmic apparatus 1 is shown in FIG. 15.

[0185] First, the model eye 500 is installed at a predetermined position for evaluating the ophthalmic device 1 (S1). In this embodiment, for example, two model eyes 500 (left model eye, right model eye) are attached to the face holding portion 450 using the attachment 460. Note that it is also possible to directly attach the model eye 500 to the chin rest, directly or indirectly attach the model eye 500 to the forehead rest, or directly or indirectly attach the model eye 500 to other parts of the ophthalmic device 1.

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

[0187] The alignment is performed, for example, until a suitable alignment state is achieved. Or, the alignment is performed over a predetermined time. Or, the alignment is performed until the number of repetitions of the alignment operation reaches a predetermined number. Note that the suitable alignment state mentioned here is a state suitable for evaluating the OCTA function, and typically, it is a state in which an OCT scan is applied to at least one liquid storage portion 630-m.

[0188] When the alignment is completed (S3), the ophthalmic device 1 applies an OCT scan to the model eye 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 may be (additionally) performed on a portion corresponding to the anterior segment of the eye (any one or more of the cornea portion 510, iris portion 520, variable portion 530, aperture 540, and lens portion 550). Also, a scan for evaluating the OCT function for structural imaging and / or a scan for evaluating the OCT function for functional imaging other than OCTA may be (additionally) performed.

[0189] The ophthalmic device 1 forms an OCTA image from the data set collected in the iterative OCT scan of step S4 by the image forming unit 220 (S5).

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

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

[0192] 〈OCTA Image of Model Eye〉 FIG. 16 shows an OCTA image obtained by an ophthalmic device in an exemplary embodiment. FIG. 16(A) is a front view (OCTA front image) 700 of an OCTA image of a model eye provided with three liquid storage parts. The three liquid storage parts provided in this model eye have the following characteristics: the forms (shapes, lengths, diameters, etc.) of the three capillaries corresponding to the three liquid storage parts are the same; liquids of different viscosities (relatively low-viscosity liquid, relatively medium-viscosity liquid, relatively high-viscosity liquid) are enclosed; the same form (materials, dimensions, etc.) of fine particles are added to the three types of liquids with different viscosities by the same amount (weight percentage).

[0193] In the OCTA front image 700, three images (three pseudo-vascular images) 701, 702, and 703 corresponding to the three liquid storage parts are depicted. The pseudo-vascular image 701 is an image caused by the Brownian motion of fine particles in a relatively low-viscosity liquid (that is, an image representing the change in light scattering by the Brownian-moving fine particles). The pseudo-vascular image 702 is an image caused by the Brownian motion of fine particles in a relatively medium-viscosity liquid (that is, an image representing the change in light scattering by the Brownian-moving fine particles). The pseudo-vascular image 703 is an image caused by the Brownian motion of fine particles in a relatively high-viscosity liquid (that is, an image representing the change in light scattering by the Brownian-moving fine particles).

[0194] That is, the pseudo-vascular image 701 is an image representing the light scattering by fine particles moving relatively fast in the liquid, and is an image with a relatively high-intensity signal. The pseudo-vascular image 702 is an image representing the light scattering by fine particles moving relatively medium-fast in the liquid, and is an image with a relatively medium-intensity signal. The pseudo-vascular image 703 is an image representing the light scattering by fine particles moving relatively slow in the liquid, and is an image with a relatively low-intensity signal.

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

[0196] The B-scan image 710 includes an image (pseudo-vascular image) 711 corresponding to the pseudo-vascular image 701. The pseudo-vascular image 711 is an image caused by the Brownian motion of fine particles in a relatively low-viscosity liquid. That is, the pseudo-vascular image 711 is an image caused by fine particles moving relatively fast in the liquid, and represents a relatively high-intensity signal.

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

[0198] The B-scan image 730 includes an image (pseudo-vascular image) 731 corresponding to the pseudo-vascular image 703. The pseudo-vascular image 731 is an image resulting from the Brownian motion of fine particles in a liquid with relatively high viscosity. That is, the pseudo-vascular image 731 is an image resulting from fine particles moving in the liquid at a relatively low speed and represents a signal with a relatively low intensity.

[0199] Note that the intensity of the signal corresponding to the pseudo-vascular image becomes higher as the contrast difference (contrast ratio) with the surroundings of the pseudo-vascular image is larger, and becomes lower as the contrast difference (contrast ratio) is smaller.

[0200] As can be seen from the image shown in FIG. 16, by using the model eye according to the exemplary embodiment, an OCTA image similar to the OCTA image of the human fundus can be obtained. That is, it can be said that the model eye according to the exemplary embodiment has characteristics approximated to those of the human fundus at least with respect to the characteristics detectable by OCTA.

[0201] <Method for manufacturing a laminate> The method for manufacturing a laminate according to the exemplary embodiment will be described. FIG. 17 shows an example of a method for manufacturing a laminate in which a liquid storage part is arranged between layers. As described above, the installation position of the liquid storage part is not limited to this (see, for example, FIGS. 9 to 12). When the liquid storage part is installed at a position other than between layers, a manufacturing method corresponding to the installation position can be adopted.

[0202] In the example shown in FIG. 17, it is assumed that some design matters of the laminate are preset. Examples of such design matters include the number of layers, the number of liquid storage parts, the position of the liquid storage parts, and the like.

[0203] Also, design matters regarding the liquid storage part may be preset in advance. For example, it is possible to determine in advance the form (shape, length, diameter, etc.) of the liquid storage part, the material of the liquid, the viscosity of the liquid, the material of the fine particles, the amount of fine particles added to the liquid, and the like.

[0204] Furthermore, the shape and dimensions (area, thickness, volume, etc.) of each layer may also be preset in advance. Note that the shape and dimensions of each layer do not necessarily have to be preset in advance. For example, the shape and dimensions of the layer may be determined and adjusted according to the state of the formed layer. In this example, for each of the plurality of layers included in the target laminate, the amount of the base material distributed in step S11-1 and the amount of the fine particles distributed in step S11-2 are preset (for example, refer to the above-mentioned addition amount of the fine particles).

[0205] In the method for manufacturing a laminate of this example, first, a predetermined number of liquid storage parts are created according to predetermined design matters (S10). The creation of the liquid storage part is performed in the manner described above (for example, refer to FIG. 8).

[0206] Next, the weighing of the material for forming the first layer is performed (S11). In this example, for the first layer, the weighing of the base material (S11-1) and the weighing of the fine particles added thereto (S11-2) are performed. Thereby, a predetermined amount of the base material and a predetermined amount of the fine particles used for forming the first layer are obtained.

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

[0208] Next, the base material into which the fine particles are put in step S12 is stirred, and degassing (deaeration) for removing the gas dissolved in the base material is performed (S13). Any known method can be used for stirring and defoaming. Thereby, unnecessary gas in the base material is removed, and the fine particles are dispersed in the base material.

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

[0210] Next, the mixture processed into a layer in step S14 is cured (S15). For this curing treatment, for example, a physical curing method such as heating or a scientific curing method using a predetermined substance is used. Thereby, the formation of the first layer is completed.

[0211] If the last layer among the preset number of layers is 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 among the predetermined number of layers (S16: No), the process proceeds to the next step S17. In this example, since two or more layers are formed, in this stage where only the first layer is formed, it is determined as "No" and the process proceeds to step S17.

[0212] When "No" is selected in step S16, one or more of the predetermined number of liquid storage parts created in step S11 are installed at a predetermined position on the upper surface of the layer formed in the immediately preceding step S15. Note that the process of step S17 is performed only when a liquid storage part is arranged between the layer formed in the immediately preceding step S15 and the layer to be formed immediately after. That is, when "No" is selected in step S16, if a liquid storage part is not arranged between the layer formed in the immediately preceding step S15 and the layer to be formed immediately after, the process of step S17 is skipped and the process proceeds to step S18. Then, steps S11 to S15 are performed again, and the next layer is formed. Also, the execution or skipping of step S17 is selected according to the preset installation position of the liquid storage part.

[0213] Steps S11 to S15 and step S17 are repeatedly executed until it is determined as "Yes" in step S16. That is, steps S11 to S15, together with step S17 that is appropriately executed, are repeatedly executed the same number of times as the number of layers set in advance. As a result, a laminate including one or more liquid storage parts in a preset arrangement and having the preset number of layers overlapping is obtained.

[0214] According to such a laminate manufacturing method, it is possible to easily and surely create a laminate including a predetermined number of layers each having a predetermined property and a predetermined number of pseudo blood vessels. In particular, since it is configured to shift to the formation process of the next layer after curing one layer, it is possible to manufacture the target laminate with high ease and high certainty.

[0215] In addition, when the laminate includes two or more layers, the same base material may be used for all the layers, or two or more base materials may be selectively used. Note that by using the same base material for all the layers, a laminate in which all the layers have the same refractive index can be obtained.

[0216] The same fine particles may be used for all the layers, or two or more fine particles may be selectively used. Also, two or more layers having the same scattering property can be continuously formed and these two or more layers can be treated as a single layer.

[0217] The model eye of the above-exemplified aspect includes a laminate including a substrate and a plurality of layers, but the model eye of other exemplified aspects may not have a plurality of layers. Some examples of such model eyes will be described below.

[0218] It is a top view of the pseudo fundus 800 shown in Fig. 18A, and the pseudo fundus 800 can be used as the fundus part 570 of the model eye 500. The pseudo fundus 800 includes a substrate 810. On the substrate 810, the liquid storage part 830-m may have the same configuration as the liquid storage part 630-m described above. The liquid storage part 830-m is fixed to the upper surface of the substrate 810 by fixing parts 840-1 and 840-2. The fixing mode by the fixing parts 840-1 and 840-2 is arbitrary, and for example, it may be adhesion using an adhesive. In this example, a plurality of layers are not provided on the substrate 810, but it is not limited to this.

[0219] When the ophthalmic device 1 applies a scan for OCTA to the pseudo fundus 800, the measurement light LS passing through the approximate center of the objective lens 22 is projected onto the pseudo fundus 800. The ophthalmic device 1 detects the return light of the measurement light LS projected onto the pseudo fundus 800 and constructs an OCTA image. Different from the case where a plurality of layers 620-1, 620-2, ···, 620-N are provided like the laminate 600 in the above-described aspect, in the pseudo fundus 800 of this aspect, since refractive index matching is not performed, a very strong specular reflection occurs. Also, specular reflection occurs on the surface of the liquid storage part 830-m (capillary). Since the measurement light LS is projected onto the pseudo fundus 800 from the front through the objective center as described above, OCTA is strongly affected by specular reflection. That is, the return light of the measurement light LS contains a large specular reflection component. Under such a state, the state of Brownian motion in the liquid storage part 830-m cannot be preferably grasped. In order to solve this problem, in this aspect, diffuse reflection is used to detect the state of Brownian motion in the liquid storage part 830-m. Hereinafter, this operation will be described with further reference to Fig. 18B.

[0220] As shown in Figs. 18A and 18B, the liquid storage part 830-m is arranged at a position deviated from the central region of the substrate 810. Reference numeral 850 indicates the range (observation range) to which a scan for OCTA is applied. Also, reference numeral 860 indicates the region onto which the measurement light LS passing through the objective center is projected. The projection region 860 of the measurement light LS is arranged in the central region of the substrate 810.

[0221] By configuring in this way, without directly projecting the measurement light LS onto the liquid storage unit 830-m, it is possible to detect the state of Brownian motion within the liquid storage unit 830-m by utilizing the diffuse reflection of the measurement light LS projected at a position deviated from the liquid storage unit 830-m. That is, the return light of the measurement light LS projected onto the projection region 860 includes the diffuse reflection light that has passed through the liquid storage unit 830-m among the diffuse reflection lights in the projection region 860, and in this aspect, it is possible to detect the state of Brownian motion within the liquid storage unit 830-m based on this diffuse reflection 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 the substrate 810A. The liquid storage unit 830A is fixed to the upper surface of the substrate 810A by the fixing unit 840A. The reference numeral 850A indicates the observation range. When the pseudo-fundus 800A is used for the evaluation of the OCTA function, since the projection region 860A of the measurement light LS overlaps with the liquid storage unit 830A, strong specular reflection is mixed into the return light of the measurement light LS, and the state of Brownian motion within the liquid storage unit 830A cannot be suitably detected. Although it is also possible to adopt an aspect with such a configuration, it is desirable to additionally provide means for preventing specular reflection. For example, it is possible to apply a coating for suppressing specular reflection to the surface of the liquid storage unit 830A and / or the upper surface of the substrate 810, provide an optical filter for attenuating or blocking specular reflection, or perform a filter process for reducing or removing the specular reflection component of the return light.

[0223] FIG. 19 shows another aspect of a pseudo-fundus with a liquid storage portion disposed at a position outside the projection region of the measurement light LS. The simulated fundus 900 includes a substrate 910. On the substrate 910, M liquid storage portions 930-1, 930-2, ···, 930-M are arranged so as to form an M-sided polygon (M is an integer of 1 or more). The M liquid storage portions 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 storage portion 930-m may have the same configuration as the liquid storage portion 630-m described above. Reference numeral 950 indicates the observation range. Also, reference numeral 960 indicates the projection region of the measurement light LS. Also in this aspect, it is possible to detect the state of Brownian motion in the liquid storage portion 930-m using diffuse reflection without being affected by strong specular reflection.

[0224] 〈Features, Actions, Effects〉 Regarding the exemplary aspects disclosed above, some features, some actions, and some effects will be described.

[0225] The model eye (500) of some exemplary aspects is used in the field of ophthalmology and includes a liquid storage portion (630-m) in which a liquid in which fine particles are suspended is stored.

[0226] According to the model eye having such a configuration, it is possible to detect the state of Brownian motion of fine particles suspended in the liquid stored in the liquid storage portion by OCTA. Therefore, the model eye of the exemplary aspect can be used as a phantom for OCTA.

[0227] Also, according to the model eye of the exemplary aspect, since Brownian motion is used to generate an OCTA signal, a fluid flow generator for mimicking blood flow is not required. Therefore, the structure of the model eye of the exemplary aspect is simple and compact. Note that the liquid storage portion may have a form imitating a blood vessel, and for example, may include a tubular body (640) in which a liquid added with fine particles is enclosed.

[0228] In order to further improve the actions and effects according to such exemplary embodiments and / or to obtain other actions and effects, it is possible to arbitrarily adopt various configurations and features described below.

[0229] The model eye (500) of some exemplary embodiments may include a plurality of liquid storage portions (630-1 to 630-M). In this case, liquids having different viscosities may be stored in the plurality of liquid storage portions (630-1 to 630-M). According to this configuration, it becomes possible to simulate and reproduce a plurality of different blood flow states.

[0230] In some exemplary embodiments, the plurality of liquid storage portions (630-1 to 630-M) may store liquids in which fine particles of different dimensions are suspended. According to this configuration, it becomes possible to simulate and reproduce a plurality of different blood flow states.

[0231] In some exemplary embodiments, at least one of the plurality of liquid storage portions (630-1 to 630-M) may be arranged to be inclined with respect to the axial direction. According to this configuration, it is possible to simulate and reproduce the blood vessel distribution of the human fundus. Further, since it becomes possible to detect signal changes due to the Doppler effect caused by Brownian motion, it is possible to use the model eye of the exemplary embodiment as a phantom for evaluating the blood flow parameter measurement function.

[0232] In some exemplary embodiments, at least two of the plurality of liquid storage portions (630-1 to 630-M) may be arranged at different inclination angles with respect to the axial direction. According to this configuration, it becomes possible to simulate and reproduce a plurality of different blood flow states.

[0233] The model eye (500) of some exemplary embodiments may further include a laminate (600) composed of a plurality of layers (620-1 to 620-N). According to such a model eye, since it has a structure similar to that of the human fundus, in addition to being used as a phantom for OCTA, it can also be used as a phantom for OCT structural imaging.

[0234] In the exemplary model eye (500), the arrangement of the liquid storage part (630-m) is arbitrary. For example, as shown in FIG. 10(A), the liquid storage part may be arranged inside any of the plurality of layers. Also, as shown in FIG. 10(B), the liquid storage part may be provided in each of at least two of the plurality of layers. Further, as shown in FIGS. 10(C) and 10(D), the liquid storage part may be arranged across at least two of the plurality of layers. These present non-limiting examples imitating the blood vessel distribution pattern in the human fundus.

[0235] Also, in some exemplary embodiments, a part of the liquid storage part may be exposed from the laminate. In the example shown in FIG. 11, both ends of the liquid storage part are exposed from the laminate, but it is not limited to such an embodiment. For example, a configuration in which only one end of the liquid storage part is exposed from the laminate or a configuration in which the central part of the liquid storage part is exposed from the laminate can be adopted. Generally, any part of the liquid storage part may be exposed from the laminate. According to such a configuration, since the liquid storage part can be visually recognized from the outside, the work of arranging the model eye with respect to the ophthalmic device can be facilitated, and the work of determining the applicable part of the OCT scan can also be facilitated.

[0236] In some exemplary embodiments, a configuration in which the orientation of the liquid storage part can be changed can be adopted. In the example shown in FIG. 12, the liquid storage part is configured to be rotatable within a plane (a plane substantially corresponding to the xy plane when the OCT scan is applied by the ophthalmic device 1) orthogonal to the direction (axial direction) in which the plurality of layers of the laminate are laminated, but the mode of changing the orientation of the liquid storage part is not limited thereto. For example, the plane to which the rotation orbit of the liquid storage part belongs is not limited to the xy plane and may be any plane. Also, the rotation direction of the liquid storage part is not limited to a single direction. For example, rotation in any two of the rotation in the xy plane, rotation in the yz plane, and rotation in the zx plane may be possible.

[0237] The model eye (500) of some exemplary embodiments may further include a first temperature control unit (470) for keeping the temperature of the liquid in the liquid storage unit (630-m) constant. According to such a configuration, the state of the Brownian motion of the fine particles floating in the liquid can be stabilized, and the performance as a phantom can be stabilized. Thereby, the accuracy, precision, and reproducibility in the performance evaluation of the OCTA function can be improved. Note that although the temperature control unit 470 in the example shown in FIG. 14 is shown as an element separate from the model eye 500, at least a part of the first temperature control unit (470) may be incorporated in the model eye (500), may be attached to the model eye (500), or may be connected to the model eye (500) by wire or wirelessly.

[0238] The model eye (500) of some exemplary embodiments may further include a second temperature control unit (470) for changing the temperature of the liquid in the liquid storage unit (630-m). According to such a configuration, the state of the Brownian motion of the fine particles floating in the liquid can be adjusted so as to exhibit a desired effect as a phantom. Note that although the temperature control unit 470 in the example shown in FIG. 14 is shown as an element separate from the model eye 500, at least a part of the second temperature control unit (470) may be incorporated in the model eye (500), may be attached to the model eye (500), or may be connected to the model eye (500) by wire or wirelessly.

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

[0240] In addition, any matter disclosed in the above exemplary embodiments can be combined with the model eye of the exemplary embodiments.

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

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

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

[0244] According to such an embodiment, since the ophthalmic device itself can perform performance evaluation, for example, it is possible to easily perform adjustment and calibration after installation in a medical institution or the like. In addition, by configuring to automatically perform regular quality evaluation and transmission of the evaluation results to a maintenance server, it becomes possible to provide a remote maintenance service. The usage method of the evaluation results is 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). This ophthalmic device may further include an alignment system (420, 420A, 420B). The alignment system is configured to perform alignment of the optical system with respect to the model eye (500) installed at a predetermined position. In addition, the evaluation unit (440) may be configured to generate evaluation information based on the data acquired from the model eye by the data acquisition unit after alignment.

[0246] According to such an aspect, it is possible to facilitate the evaluation work of the ophthalmic device using the model eye. That is, in order to appropriately perform the evaluation using the model eye, it is necessary to accurately place the model eye with respect to the optical system of the ophthalmic device to be evaluated. However, according to the ophthalmic device of this aspect, complicated work such as manually adjusting the position of the model eye is no longer required.

[0247] Moreover, according to this aspect, it is possible to evaluate the ophthalmic device in a state where the model eye is installed in a suitable alignment state. Therefore, it is possible to appropriately evaluate the ophthalmic device. For example, according to this aspect, it is possible to improve the accuracy, precision, and reproducibility in the evaluation of the ophthalmic device.

[0248] In addition, according to this aspect, it is possible to perform not only the evaluation of the imaging performance and measurement performance of the ophthalmic device but also the evaluation of the alignment performance.

[0249] In the ophthalmic device (1) of some exemplary aspects, the data acquisition unit (2, 100, 210, 220; 410) can execute at least two acquisitions of data from a specific part of the model eye (500). Furthermore, the evaluation unit (440) can generate evaluation information based on two or more pieces of data acquired from the specific part of the model eye by the data acquisition unit. By adopting this configuration, it becomes possible to perform the performance evaluation of the OCTA function by the ophthalmic device itself.

[0250] It should be noted that any matter disclosed in the above exemplary aspects can be combined with the ophthalmic device of the exemplary aspects.

[0251] The above disclosure is merely an example of the implementation of this invention. Those who attempt to implement this invention can perform any modifications (omission, substitution, addition, etc.) within the scope of the gist of this invention.

Explanation of Reference Numerals

[0252] 1 Ophthalmic device 500 Model eye 630-m (m = 1, ···, M; M is an integer of 1 or more) liquid storage section

Claims

1. a data acquisition unit for optically acquiring eye data; A model eye having a structure simulating an eye for evaluating the data acquisition unit; an evaluation unit that generates evaluation information based on the data acquired from the eye model by the data acquisition unit; Including, The eye model includes a liquid storage section that stores a liquid in which fine particles are suspended, The liquid storage unit is disposed so as to be inclined non-perpendicularly with respect to an axial direction that corresponds to the ocular axis of the eye, The evaluation unit obtains blood flow parameters including at least one of a blood flow velocity and a blood flow volume as the evaluation information. Ophthalmology equipment.

2. The eye model further includes a laminate consisting of a plurality of layers. The ophthalmic device of claim 1.

3. The liquid storage section is disposed within any one of the plurality of layers. The ophthalmic device of claim 2.

4. The liquid storage section is provided in each of at least two layers among the plurality of layers. The ophthalmic device of claim 2.

5. The liquid storage section includes a tubular body in which the liquid is sealed. The ophthalmic apparatus according to any one of claims 1 to 4.

6. The data acquisition unit includes an optical system. an alignment system that aligns the optical system with a model eye installed at a predetermined position; The evaluation unit generates the evaluation information based on data acquired from the model eye by the data acquisition unit after the alignment. The ophthalmic apparatus according to any one of claims 1 to 5.

7. The data acquisition unit executes acquisition of data from a specific portion of the eye model at least twice, 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. The ophthalmic apparatus according to any one of claims 1 to 6.

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