JP7488090B2 - Model eye and ophthalmic device - Google Patents

Description

This invention relates to a model eye and an ophthalmic device.

Various imaging modalities are used in ophthalmology, a representative example being optical coherence tomography (OCT). OCT is used for functional imaging as well as structural imaging.

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

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

JP 2015-515894 A JP 2012-110575 A JP 2019-76181 A

Jigesh Baxi and 7 others, "Retina-simulating phantom for optical coherence tomography", Journal of Biomedical Optics, February 2014, Vol. 19, No. 2, 021106-1 to 021106-8

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

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

One object of the present invention is to provide a model eye suitable as a phantom for OCTA and an ophthalmic device equipped with the same.

Some exemplary embodiments include a model eye for use in the field of ophthalmology, which includes a liquid storage section that contains a liquid in which particles are suspended.

Some exemplary embodiments of the model eye include multiple liquid storage sections.

In some exemplary embodiments, the liquid storage units store liquids of different viscosities.

In some exemplary embodiments, the liquid storage sections store liquids in which particles of different sizes are suspended.

In some exemplary embodiments, at least one of the liquid storage sections is disposed at an angle relative to the axial direction.

In some exemplary embodiments, at least two of the liquid storage sections are disposed at different inclination angles relative to the axial direction.

In some exemplary embodiments, the liquid storage section is disposed at an angle relative to the axial direction.

Some exemplary embodiments of the model eye further include a laminate of multiple layers.

In some exemplary embodiments, the liquid storage section is disposed within one of the layers.

In some exemplary embodiments, at least two of the layers are each provided with the liquid storage section.

In some exemplary embodiments, the liquid storage section is disposed across at least two of the multiple layers.

In some exemplary embodiments, a portion of the liquid storage section is exposed from the laminate.

In some exemplary embodiments, the orientation of the liquid storage section can be changed.

Some exemplary embodiments of the model eye further include a first temperature control unit for maintaining a constant temperature of the liquid.

Some exemplary embodiments of the model eye further include a second temperature control unit for varying the temperature of the liquid.

In some exemplary embodiments, the liquid storage section includes a tubular body in which the liquid is sealed.

Some exemplary aspects are ophthalmic devices that include a data acquisition unit for optically acquiring data of an eye and a model eye for evaluating the data acquisition unit, the model eye including a liquid storage unit that stores a liquid in which fine particles are suspended.

Some exemplary aspects of the ophthalmic device further include an evaluation unit that generates evaluation information based on the data acquired from the model eye by the data acquisition unit.

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

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

According to some exemplary aspects, it is possible to provide a model eye suitable as a phantom for OCTA or an ophthalmic device equipped with the same.

1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of a model eye according to an exemplary embodiment. FIG. 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. FIG. FIG. 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. 1A-1C are schematic diagrams illustrating a method and configuration for creating a liquid containment section in an eye model according to an exemplary embodiment. 1 is a schematic diagram showing the arrangement of a liquid containment section in an eye model according to an exemplary embodiment. FIG. 1 is a schematic diagram showing the arrangement of a liquid containment section in an eye model according to an exemplary embodiment. FIG. 1 is a schematic diagram showing the arrangement of a liquid storage section in an eye model according to an exemplary embodiment. FIG. 1 is a schematic diagram showing the arrangement of a liquid storage section in an eye model according to an exemplary embodiment. FIG. 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. 1 is a flowchart illustrating operations that can be performed by an ophthalmic apparatus according to an exemplary embodiment. 1 is an OCTA image of an eye model according to an exemplary embodiment. 1 is a flow chart illustrating a method for manufacturing a laminate according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of a model eye according to an exemplary embodiment. 1 is a schematic diagram for explaining a model eye according to an exemplary embodiment. FIG. 1 is a schematic diagram for explaining a model eye according to an exemplary embodiment. FIG. 1 is a schematic diagram for explaining a model eye according to an exemplary embodiment. FIG.

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

The ophthalmic device according to the exemplary embodiment described below is a multifunction 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 to this and may be any ophthalmic device having an OCTA function. The ophthalmic device according to some exemplary embodiments has at least one of an alignment function and a performance evaluation function. The ophthalmic device according to some exemplary embodiments includes a model eye for performance evaluation. On the other hand, the ophthalmic device according to some exemplary embodiments does not include a model eye for performance evaluation.

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

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

In contrast, swept-source OCT splits the light from a tunable light source into measurement light and reference light, superimposes the return light of the measurement light from the test object with the reference light to generate interference light, detects this interference light with a photodetector such as a balanced photodiode, and forms an image by performing a Fourier transform or the like on the detection data collected in response to the wavelength sweep and the measurement light scan.

In this way, 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.

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

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

The fundus camera unit 2 is provided with a chin rest and a forehead rest for holding the subject's face. The chin rest and the forehead rest correspond to the face holder 450 shown in Figures 4A and 4B. The base 310 houses a drive mechanism and an arithmetic and control circuit. The housing 320 provided on the base 310 houses an optical system. The lens housing section 330 protrudes from the front of the housing 320 and houses the objective lens 22.

Furthermore, the ophthalmic device 1 is provided with a lens unit for switching the area to which OCT is applied. Specifically, the ophthalmic device 1 is provided with 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, JP 2015-160103 A.

As shown in FIG. 1, the anterior segment OCT attachment 400 can be positioned between the objective lens 22 and the subject's eye E. When the anterior segment OCT attachment 400 is positioned 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 anterior segment OCT attachment 400 is moved manually or automatically.

In some aspects, an OCT scan may be applied to the posterior segment when the attachment is disposed in the optical path, and an OCT scan may be applied to the anterior segment when the attachment is retracted from the optical path. In addition, the measurement site switched by the attachment is not limited to the posterior segment and the anterior segment, but may be any part 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 it is also possible to adopt, for example, a configuration including a lens that can be moved along the optical path, or a configuration including a lens that can be inserted and removed from the optical path.

At least a portion of the functionality of the elements disclosed in this specification is implemented using circuitry or processing circuitry. The circuitry or processing circuitry may be a general purpose processor, a special purpose processor, an integrated circuit, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), a Field Programmable Gate Array (FPGA), a FPGA, a FPGA, a FPGAs ... Array), conventional circuitry, and any combination thereof. A processor is considered to be a processing circuitry or circuitry, including transistors and/or other circuitry. In this disclosure, a circuitry, unit, means, or similar term is hardware that performs at least some of the disclosed functions or hardware that is programmed to perform at least some of the disclosed functions. The hardware may be hardware disclosed herein or known hardware that is programmed and/or configured to perform at least some of the described functions. If the hardware is a processor that can be considered as a type of circuitry, the circuitry, unit, means, or similar term is a combination of hardware and software, and the software is used to configure the hardware and/or the processor.

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

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

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 passes through the visible cut filter 14 to become near-infrared light. Furthermore, the observation illumination light is once focused near the photographing light source 15, reflected by the mirror 16, and is guided to the aperture mirror 21 via the relay lens system 17, the relay lens 18, the aperture 19, and the relay lens system 20. The observation illumination light is then reflected at the periphery (area around the hole) of the aperture mirror 21, passes through the dichroic mirror 46, and is refracted by the objective lens 22 to illuminate the subject's eye E (fundus Ef). The return light of the observation illumination light from the subject's eye E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central area of the aperture mirror 21, passes through the dichroic mirror 55, passes through the photographing focusing lens 31, and is reflected by the mirror 32. Furthermore, 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. The focus of the photographing optical system 30 can be adjusted to match the fundus Ef or its vicinity, and can also be adjusted to match the anterior segment or its vicinity.

The light output from the imaging light source 15 (imaging illumination light) is irradiated onto the fundus Ef via the same path as the observation illumination light. The return light of the imaging illumination light from the subject's eye E is guided to the dichroic mirror 33 via 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 by the imaging lens 37 on the light receiving surface of the image sensor 38.

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

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

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

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

The alignment optical system 50 generates an alignment index used to align the optical system with the subject's eye E. 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 hole in the aperture mirror 21, transmits through the dichroic mirror 46, and is projected onto the subject's eye E via the objective lens 22. The return light of the alignment light from the subject's eye E is guided to the image sensor 35 via the same path as the return light of the observation illumination light. Manual alignment or auto alignment can be performed based on the received light image (alignment index image).

The alignment method applicable to the exemplary embodiment is not limited to those using such alignment indicators, and may be any known method, such as a method using an anterior eye camera 300, a method using a corneal reflection image (Purkinje image) formed by projecting a light beam from the front onto the cornea, or a method using an optical lever that projects a light beam obliquely onto the cornea and detects the corneal reflection in the opposite direction.

The focus optical system 60 generates a split index used for focus adjustment of the subject's eye E. In conjunction with the movement of the photographing focusing lens 31 along the optical path (photographing optical path) of the photographing optical system 30, the focus optical system 60 is moved along the optical path (illumination optical path) of the illumination optical system 10. The reflecting rod 67 is inserted and removed from the illumination optical path. When performing focus adjustment, the reflecting surface of the reflecting rod 67 is tilted and positioned on 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, and is once imaged and reflected on the reflecting surface of the reflecting rod 67 by the condenser lens 66. Furthermore, 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 subject's eye E via the objective lens 22. The return light (fundus reflection light, etc.) of the focusing light from the subject's eye E is guided to the image sensor 35 via the same path as the return light of the alignment light. Manual focusing or autofocusing can be performed based on the received light image (split target image).

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

The dichroic mirror 46 combines the optical path for fundus imaging with the optical path for OCT (measurement arm). The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for fundus imaging. The measurement arm is provided with 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, in that order from the OCT unit 100 side.

The retroreflector 41 can be moved along the optical path of the measurement light LS incident on it, thereby changing the length of the measurement arm. Changing the measurement arm length is used, for example, to correct the optical path length according to the axial length of the eye, or to adjust the interference state.

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

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

The optical scanner 44 is substantially disposed at a position optically conjugate with the pupil of the subject's eye E. The optical scanner 44 deflects the measurement light LS guided by the measurement arm. The optical scanner 44 is, for example, a galvano 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 with the pupil, or a position optically conjugate with the pupil is disposed between these one-dimensional scanners.

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

The light source unit 101 outputs broadband low-coherence light L0. The low-coherence light L0 includes, for example, a wavelength band in the near-infrared region (approximately 800 nanometers to 900 nanometers) and has a temporal coherence length of approximately several tens of micrometers. Note that the low-coherence light L0 may be near-infrared light having a central wavelength of approximately 1040 to 1060 nanometers, for example, a wavelength band that is not visible to the human eye. The light source unit 101 includes optical output devices such as superluminescent diodes (SLDs), LEDs, and semiconductor optical amplifiers (SOAs).

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

The low-coherence light L0 output from the light source unit 101 is guided by an optical fiber 102 to a polarization controller 103, where its polarization state is adjusted. The light L0 whose polarization state has been adjusted is guided by an optical fiber 104 to a fiber coupler 105, where it is split into a measurement light LS and a reference light LR. The optical path that guides the measurement light LS is called the measurement arm, and the optical path that guides the reference light LR is called the reference arm.

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

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

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

The fiber coupler 122 generates interference light LC by superimposing the measurement light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121.

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

In addition, when swept-source OCT is employed, 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 are guided to the photodetector. The photodetector includes, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that detect the pair of interference lights, respectively, and outputs the difference between the pair of detection signals obtained by these. The photodetector sends this output (detection signal such as a difference signal) to the data acquisition system (DAQ). The data acquisition system is supplied with a clock from the light source unit. The clock is generated in the light source unit in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength-variable light source. For example, the light source unit branches light of each output wavelength to generate two branch lights, optically delays one of the branch lights, combines the branch lights, detects the obtained combined 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 from this sampling is used for processing such as image construction.

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

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

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 storage devices such as the hard disk drive. The arithmetic control unit 200 may also include an operation device, an input device, a display device, and the like.

As shown in FIG. 3A, the user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes, for example, the display device 3. The operation unit 242 includes various operation devices and input devices. The user interface 240 may include a device that integrates a display function and an operation function, such as a touch panel. An ophthalmic device according to some exemplary aspects 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 device.

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

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

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

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

Typically, the anterior segment is photographed from two or more different directions substantially simultaneously. "Substantially simultaneously" refers not only to the case where the timing of photographing the anterior segment from two or more different directions is simultaneous, but also to the case where, for example, there is a timing difference that allows eye movement to be ignored. Such substantially simultaneous photographing makes it possible to photograph the anterior segment from two or more different directions when the subject's eye E is in substantially the same position and orientation.

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

However, when photographing a model eye as described below, such substantially simultaneous photographing is not necessary.

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

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

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

The imaging focusing lens 31 arranged in the imaging optical path and the focus optical system 60 arranged in the illumination optical path are moved integrally or in cooperation with each other by an imaging focusing drive unit (not shown) under the control of the main control unit 211. The retroreflector 41 provided in 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 provided in the measurement arm is moved by an OCT focusing drive unit 43A under the control of the main control unit 211. The movement of the OCT focusing lens 43 can be performed in cooperation with the movement of the imaging focusing lens 31 and the focus optical system 60. The retroreflector 114 provided in 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 illustrated 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 in the measurement arm operates under the control of the main control unit 211. Furthermore, the main control unit 211 can control any element included in the ophthalmic apparatus 1, such as the polarization controller 103, the polarization controller 118, the attenuator 120, various light sources, various optical elements, various devices, and various mechanisms. The main control unit 211 may also be capable of controlling any peripheral equipment (apparatus, equipment, device, etc.) connected to the ophthalmic apparatus 1, and any equipment, equipment, device, etc. accessible by the ophthalmic apparatus 1.

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

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

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

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

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

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

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

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

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

Data Processing Unit 230
The data processing unit 230 executes various types of data processing. For example, the data processing unit 230 can apply image processing and analysis processing to OCT image data, and can apply image processing and analysis processing to 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 cooperation between hardware including a circuit and data processing software.

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

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

An exemplary configuration of the model eye 500 is shown in FIG. 5. The model eye 500 of this example includes a cornea portion 510 (cornea-equivalent lens) corresponding to the cornea, an iris portion 520 corresponding to the iris, a lens portion 550 (lens-equivalent lens) corresponding to the lens, a vitreous portion 560 corresponding to the vitreous body, and a fundus portion 570 corresponding to the fundus. The number of elements (e.g., the number of lenses) included in the model eye 500 is arbitrary.

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

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

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

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

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

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

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

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

The fundus portion 570 is constructed using a laminate. Some exemplary aspects of laminates that can be applied to the fundus portion 570 are described with reference to Figures 6A, 6B, 7, 8, 9, 10, 11, and 12.

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

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

The multiple layers 620-1, 620-2, ..., 620-N are formed on the substrate 610. The multiple layers 620-1, 620-2, ..., 620-N and the substrate 610 are integrally configured. That is, the bottom surface of the layer 620-N located at the bottom of the multiple layers 620-1, 620-2, ..., 620-N is directly or indirectly bonded to the top surface of the substrate 610. As an example of indirect bonding, an anti-reflection film can be disposed between the bottom surface of the layer 620-N and the top surface of the substrate 610.

The substrate 610 is typically formed of a transparent crystal. The material of the substrate 610 may be, for example, at least one of silicon dioxide (SiO ₂ ), calcium fluoride (CaF ₂ ), aluminum oxide (Al ₂ O ₃ ), magnesium fluoride (MgF ₂ ), zinc selenide (ZnSe), germanium (Ge), calcium carbonate (CaCO ₃ ), polymethylmethacrylate resin, polyimide resin, polyethylene resin, and polycarbonate resin, but is not limited thereto. Note that in some exemplary aspects, the laminate may or may not include a substrate.

Layer 620-n has characteristics (structure, function, properties) that mimic some tissues (layered tissue, membranous tissue) of the human fundus. For example, layer 620-n has characteristics (structure, function, properties) that correspond to one tissue of the human fundus, one sub-tissue of one tissue, a combination of two or more sub-tissues of one tissue, a combination of two or more tissues, or a combination of two or more of these.

The layer 620-n is formed by at least a substrate and microparticles dispersed in the substrate. In some exemplary embodiments, the substrates in the layers 620-1, 620-2, ..., 620-N have refractive indices that are (substantially) equal to each other. The substrate 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.

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

When the substrate refractive index is determined according to the refractive index of one or more sub-tissues of the human fundus, the substrate refractive index may be, for example, the standard refractive index of a predetermined portion (one or more sub-tissues) of the human fundus or a refractive index that is approximate to the standard refractive index. Alternatively, the substrate refractive index may be a refractive index (statistical value: average value, median value, 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 that is approximate to the standard refractive index of a predetermined representative sub-tissue of the human fundus. The standard refractive index is 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 substrate refractive index may include the human retina or one or more sub-tissues of the human retina, and/or the human choroid or one or more sub-tissues of the human choroid.

For example, the refractive index of the human retina is about 1.38, and in order to achieve a substrate refractive index equivalent to that of the human fundus, it is thought that a value of about 1.40 or less must be achieved. For this purpose, an organosilicon compound can be used as the substrate material. This makes it possible to reduce the substrate refractive index to about 1.41. In addition, by using a fluorine compound as the substrate material, the substrate refractive index can be reduced to less than 1.40.

The characteristics considered in the design of the multiple 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), diffusion characteristics (diffusivity, diffusion coefficient, diffusion degree) can be considered.

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

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

When the thickness of layer 620-n is referred to in determining the scattering properties of layer 620-n, the layer thickness can be set within the range of 5 micrometers to 500 micrometers, but is not limited to this. Also, the thickness of stack 600 can be within the range of 50 micrometers to 700 micrometers, for example, but is not limited to this.

To determine the scattering properties of layer 620-n, the particulate material may be at least one of aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), calcium carbonate (CaCO ₃ ), barium sulfate (BaSO ₄ ), polymethylmethacrylate resin, polyimide resin, polyethylene resin, and polycarbonate resin, but is not limited thereto.

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

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

An example of the schematic configuration of two layers in the laminate thus constructed is shown in FIG. 7. The layer 620-n ₁ in FIG. 7 corresponds to any one of the layers 620-1, 620-2, ..., 620-N in FIG. 6, and the layer 620-n ₂ corresponds to the other layer. The refractive index of the substrate 621-n ₁ of the layer 620-n ₁ and the refractive index of the substrate 621-n ₂ of the layer 620-n ₂ are equal to each other. In addition, the two layers 620-n ₁ and 620-n ₂ have different scattering properties. In order to control such scattering properties, the particles 622-n ₁ in the layer 620-n ₁ and the particles 622-n ₂ in the layer 620-n ₂ are different from each other in at least both size and amount of addition.

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

An example of a method for producing the liquid storage unit 630-m and an example of the configuration will be described with reference to FIG. 8. In this example, in the first step (A), a capillary (capillary tube, tubular body) 640 that imitates blood vessels in the fundus is prepared. Both ends of the capillary 640 are open. The material of the capillary 640 may be at least one of silicon dioxide (SiO ₂ ), polymethylmethacrylate resin, polypropylene, and vinylidene chloride resin, but is not limited to these. The inner diameter of the capillary 640 (diameter of the hollow region) may be, for example, within a range of 10 micrometers to 300 micrometers.

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

In the next step (B), liquid 641 in which the particles are suspended is injected into capillary 640. This causes the hollow region of capillary 640 to be filled with liquid 641 in which the particles are suspended.

In the next step (C), both ends (openings) of the capillary 640, whose hollow region is filled with liquid 641 in which the fine particles are suspended, are blocked. Any method can be used to block the openings, for example, welding. The locations at both ends of the capillary 640 blocked in this way are indicated by the reference symbols 642 and 643.

In the next step (D), a cover 644 is attached to cover the blocked portion 642 at the first end of the capillary 640, and a cover 645 is attached to cover the blocked portion 64 at the second end.

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

When multiple liquid storage sections 630-1, ..., 630-M (M is an integer of 2 or more) are provided, these liquid storage sections 630-1, ..., 630-M may have different features (configuration, function, properties) from each other. For example, the multiple liquid storage sections 630-1, ..., 630-M may have different forms from each other. Typically, the multiple liquid storage sections 630-1, ..., 630-M may have different shapes from each other and/or different dimensions from each other (length, thickness, diameter, etc.). In addition, the multiple liquid storage sections 630-1, ..., 630-M may be formed from different materials from each other.

The multiple liquid storage units 630-1, ..., 630-M may be configured so that the movement speeds of the 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 particles may be considered. The parameter considered may be any parameter that affects the Brownian motion of the particles in the liquid. For example, the movement speed of the particles floating in the liquid can be controlled by adjusting any parameter among the viscosity of the liquid, the temperature of the liquid, and the form (shape, size) of the particles. That is, the multiple liquid storage units 630-1, ..., 630-M may store liquids of different viscosities, may store liquids of different temperatures, and may store liquids in which particles of different sizes float.

9A, the liquid storage section 630-m may be arranged at an incline with respect to a predetermined axis direction 650. The axis direction 650 may be defined by the model eye (laminate 600A, 600B) and/or the evaluation method. For example, the axis direction 650 may be a direction corresponding to the eye axis in the model eye (laminate 600A, 600B) having a structure simulating an eye. Alternatively, the axis direction 650 may be a direction in which multiple layers in this laminate (600A, 600B) are laminated (i.e., the thickness direction, depth direction, etc. of the laminate). Alternatively, the axis direction 650 may be an axis direction used in OCT (i.e., the z direction, A-scan direction, measurement light incidence direction, etc.). By tilting in this way, it is possible to obtain blood flow parameters (blood flow velocity, blood flow amount, etc.) in addition to the presence or absence of blood flow. In other words, it is possible to evaluate the amount of Doppler shift caused by the direction of blood flow.

In the case where 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 at an inclination with respect to the axial direction 650. Furthermore, at least two of these liquid storage units 630-1, ..., 630-M may be arranged at different inclination angles with respect to the axial direction 650. For example, as shown in FIG. 9B, both of the two liquid storage units 630-m ₁ and 630-m ₂ may be inclined with respect to the axial direction 650, and the inclination angle of the liquid storage unit 630-m ₁ with respect to the axial direction 650 and the inclination angle of the liquid storage unit 630-m ₂ with respect to the axial direction 650 may be different from each other. This makes it possible to obtain information that represents the relationship between the inclination angle and the blood flow parameter. For example, it is possible to obtain blood flow parameters for each of the different inclination angles, and it is possible to perform an evaluation according to the inclination angle. In addition, it is possible to obtain the change and sensitivity of the blood flow parameter according to the change in the inclination angle, and it is possible to perform an evaluation according to the change.

In the case where a model eye including a laminated body made of multiple layers is adopted, such as the model eye 500 of this example, the arrangement relationship between the multiple layers and the liquid storage unit may be arbitrary. For example, as shown in FIG. 6A, a liquid storage unit may be arranged between layers. Also, as shown in FIG. 10(A), a liquid storage unit 630-m may be arranged inside any layer 620-n of the laminate. Also, as shown in FIG. 10(B), a liquid storage unit 630-m may be arranged inside layer 620-n of the laminate, and a liquid storage unit 630-(m+1) may be arranged inside layer 620-(n+1). Note that the number of layers in which the liquid storage unit is provided is arbitrary, and the two layers in which the liquid storage unit is provided may or may not be adjacent to each other. As shown in FIG. 10(C), a single liquid storage unit 630-m may be arranged across two layers 620-n and 620-(n+1) of the laminate. Note that the liquid storage unit may be arranged across three or more layers. Another example in which a single liquid storage section 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 section 630-m is arranged at an angle to a specific axial direction. These are some examples of model eyes that mimic the distribution of blood vessels in the fundus.

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

In some exemplary embodiments, it is possible to adopt a configuration in which a part of the liquid storage section 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 section 630 provided in the laminate 600C is embedded in the laminate 600C, and both ends 630b and 630c are exposed from the laminate 600C. The user can grasp the position of the liquid storage section 630 by referring to the exposed ends 630b and 630c. This makes it possible to determine the range to which the OCT scan for performance evaluation is applied and the orientation in which the model eye is placed.

The above is not a limitation of the embodiments that can be adopted to achieve the same effect. For example, marks indicating the position of the liquid storage unit embedded in the laminate can be provided on the outer surface of the model eye, the outer surface of the fundus, and the outer surface of the laminate. Alternatively, the laminate can be formed using a transparent material.

The orientation of the liquid storage unit when performing an OCT scan for performance evaluation of the ophthalmologic device 1 may be arbitrary. In addition, it is possible to configure one or more of the model eye, the fundus, and the laminate to be movable and/or variable, or to configure one or more of a part of the model eye, a part of the fundus, and a part of the laminate to be movable and/or variable. For example, as shown in Figures 12(A) and 12(B), the laminate 600D can be configured to be rotatable around a predetermined axis, thereby making it possible to change the orientation of the liquid storage unit 630D.

In some exemplary embodiments, a liquid having a high viscosity such that Brownian motion of particles does not substantially occur may be enclosed in the capillary. In the evaluation of OCTA function, the purpose is to obtain a signal (motion signal) representing the motion of particles in liquid. According to this embodiment, a signal (reference signal) for a state in which the motion of particles is substantially zero is obtained, and the motion signal can be analyzed using this reference signal. For example, the motion signal can be corrected by using the reference signal as an offset. In addition, noise in the motion signal can be removed by treating the reference signal as a signal representing inherent noise generated from the group of elements for OCTA (optical system, processing system, etc.). In addition, the reference signal can be used for evaluation and calibration of a model eye for acquiring a motion signal (i.e., a model eye including a capillary filled with a liquid having a low viscosity in which Brownian motion of particles occurs). For example, it is possible to refer to the difference (difference, ratio, etc.) between the reference signal and the motion signal in order to adjust the parameters (temperature, etc.) of the model eye for acquiring a motion signal.

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

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 detachably attached to the attachment 460. For example, the model eye 500 is attached to the attachment 460, and the attachment 460 is attached to the face holder 450. In other words, the model eye 500 is indirectly attached to the ophthalmic device 1 via the attachment 460.

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

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

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

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

<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 .

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

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.

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 to move the data acquisition optical system 410 by the calculated three-dimensional movement amount (movement amount in the x direction, movement amount in the y direction, and movement amount in the z direction).

For details of the processing performed by the processing unit 430, please refer to a series of documents by the present applicant relating to inventions using two or more anterior eye cameras, such as JP 2013-248376 A and JP 2014-113385 A. The processing unit 430 is realized, for example, by the main control unit 211 and the data processing unit 230.

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

Some exemplary aspects of the ophthalmic device may be capable of performing the XY alignment and/or Z alignment described in JP 2018-164616 A by the present applicant. XY alignment is an alignment method that uses a corneal reflection image (Purkinje image), and Z alignment is an alignment method that uses an optical lever.

When applying a technique using a corneal reflection image (Purkinje image) to the alignment of the data acquisition optical system 410 with respect to the model eye 500, the configuration shown in FIG. 13A, for example, 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 with alignment system 420A. Among the elements shown in FIG. 13A, elements similar to those in FIG. 3B are indicated by the same reference numerals, and unless otherwise noted, the description of those elements will not be repeated.

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

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

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 portion of the optical path of the data acquisition optical system 410. This forms a bright spot image (corneal reflection image, Purkinje image) on the cornea of the model eye 500.

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

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

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 relative to a predetermined reference position (e.g., a position corresponding to the optical axis of the data acquisition optical system 410), and controls the moving mechanism 150 to cancel this deviation (so that the corneal reflection image is positioned at the reference position). This makes it possible to guide the optical axis of the data acquisition optical system 410 to the apex position of the cornea of the model eye 500.

For details of the processing performed by the processing unit 430A, please refer to, for example, JP 2018-164616 A and JP 10-024019 A. The processing unit 430A is realized, for example, by the main control unit 211 and the data processing unit 230.

When applying the technique using an optical lever to the alignment of the data acquisition optical system 410 to the model eye 500, the configuration shown in FIG. 13B, for example, can be adopted instead of the configuration shown in FIG. 3B. In the configuration example shown in FIG. 13B, the alignment system 420 shown in FIG. 3B is replaced with alignment system 420B. Among the elements shown in FIG. 13B, the same elements as those in FIG. 3B are indicated by the same reference numerals, and unless otherwise noted, the description of those elements will not be repeated.

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

The alignment system 420B includes a projection unit 421B, an imaging unit 422B, a processing unit 430B, and a movement mechanism 150.

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

The photographing unit 422B is arranged in a direction approximately symmetrical to the projection direction of the light beam by the projection unit 421B with respect to the optical axis of the data acquisition optical system 410. Typically, the projection unit 421B and the photographing unit 422B are arranged in positions approximately symmetrical to each other with respect to the optical axis of the data acquisition optical system 410. The photographing unit 422B is typically a line sensor in which a plurality of light receiving elements are arranged one-dimensionally. Note that the photographing 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) by the cornea of the light beam emitted from the projection unit 421B is detected by the photographing unit 422B. When the corneal reflected light is not detected by the photographing unit 422B, the image obtained by the photographing unit 422B is an entirely black image. On the other hand, when the corneal reflected light is detected by the photographing unit 422B, the image obtained by the photographing unit 422B includes a bright spot image. The image obtained by the photographing unit 422B is input to the processing unit 430B.

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

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

For details of the processing performed by the processing unit 430B, please refer to, for example, JP 2018-164616 A and JP 2015-146859 A. The processing unit 430B is realized, for example, by the main control unit 211 and the data processing unit 230.

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, the ophthalmic apparatus 1 aligns the data acquisition optical system 410 with respect to the model eye 500 by the alignment system 420, and then applies an OCT scan to the model eye 500 by the data acquisition optical system 410. This OCT scan is typically a scan for OCTA, and applies scans to a specific portion of the model eye 500 a predetermined number of times.

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. The evaluation unit 440 may also be configured to generate alignment quality evaluation information indicating the quality of the alignment performed by the alignment system.

When generating 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 device 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, for example, compares the formed image of the fundus 570 with a predetermined evaluation image. This evaluation image is, for example, an image of the fundus 570 with high data quality. The evaluation unit 440 can generate data quality evaluation information based on the result of the comparison between the image of the fundus 570 and the evaluation image.

In this embodiment, the evaluation unit 440 is configured to perform a quality evaluation of the OCTA data. The ophthalmic device 1 applies an OCT scan to an area of the fundus 570 including at least a part of at least one of the liquid storage units 630-1, ..., 630-M by the data acquisition optical system 410 a predetermined number of times. For example, the ophthalmic device 1 may repeatedly apply an OCT scan to the entire fundus 570. The image forming unit 220 constructs a motion contrast image from a data set collected by this repeated OCT scan. This motion contrast image is a simulated (pseudo) angiographic image that emphasizes and visualizes the temporal change of the interference signal caused by the Brownian motion of the particles in the liquid storage unit 630-m. This simulated angiographic image is three-dimensional image data, and the image forming unit 220 can construct any two-dimensional image data and/or any three-dimensional image data from this three-dimensional image data as described above. The evaluation unit 440 can generate quality evaluation information for the OCTA data, for example, by comparing the constructed image of the fundus 570 (OCTA image) with a specified evaluation image.

As another example of generating data quality evaluation information, the evaluation unit 440 can determine the value of a predetermined evaluation parameter that represents data quality by analyzing the data acquired by the data acquisition optical system 410. The evaluation parameter may be, for example, an image quality evaluation parameter such as contrast or S/N ratio. The evaluation parameter may also be, for example, a measurement quality evaluation parameter such as a measurement accuracy parameter or a measurement precision parameter.

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

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

In some exemplary aspects, the evaluation unit 440 can generate alignment quality evaluation information based on the content of the processing performed by the alignment system 420 (420A, 420B). For example, the evaluation unit 440 can generate alignment quality evaluation information based on the number of repetitions of the alignment operation performed from the start of the alignment to reaching a suitable alignment state. The alignment operation is, for example, the number of times the processing unit 430 (430A, 430B) processes an 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, and evaluate the number of repetitions as "low quality" if the number of repetitions exceeds the threshold, and evaluate the number of repetitions as "high quality" if the number of repetitions is equal to or less than the threshold. Alternatively, the evaluation unit 440 may be configured to determine which of a plurality of predetermined ranges (high quality range, acceptable range, poor range) the number of repetitions belongs to, and generate alignment quality evaluation information based on the range to which the number of repetitions belongs.

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

As mentioned above, temperature is a parameter that affects the Brownian motion of particles in 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 the configuration shown in FIG. 3B to which a temperature control unit 470 has been added. Note that configurations capable of executing liquid temperature control are not limited to this, and for example, the temperature control unit 470 or an element equivalent thereto may be added to any of the following: a configuration equivalent to the configuration shown in FIG. 3B, the configuration shown in FIG. 13A or an equivalent thereto, the configuration shown in FIG. 13B or an equivalent thereto, and any other mode of configuration.

In the 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 hot 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, the temperature of the liquid stored in the liquid storage unit 630-m can be kept almost constant, so that the state of Brownian motion of the particles floating in the liquid (such as the moving speed of the particles) can be stabilized. This makes it possible to improve the accuracy, precision, reproducibility, etc. of the performance evaluation of the ophthalmic device 1.

In the 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, the temperature of the liquid stored in the liquid storage unit 630-m can be changed to a desired temperature, so that the state of Brownian motion of the particles floating in the liquid (such as the movement speed of the particles) can be brought to a desired state. This makes it possible to improve the accuracy, precision, reproducibility, etc. of the performance evaluation of the ophthalmic device 1.

<motion>
An example of the operation of the ophthalmic apparatus 1 according to this embodiment will be described below. An example of the operation of the ophthalmic apparatus 1 is shown in FIG.

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

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

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

When the alignment is completed (S3), the ophthalmologic apparatus 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 of the portion corresponding to the anterior segment (one or more of the cornea 510, iris 520, variable portion 530, aperture 540, and lens 550) may be (additionally) performed. Also, a scan for evaluating 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.

The ophthalmic device 1 uses the image forming unit 220 to form an OCTA image from the data set collected by the repetitive OCT scan in step S4 (S5).

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

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

<OCTA image of model eye>
16 shows OCTA images obtained by an ophthalmic device according to 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 sections. The three liquid storage sections provided in this model eye have the following characteristics: the three capillaries corresponding to the three liquid storage sections have the same form (shape, length, diameter, etc.); liquids with different viscosities (relatively low viscosity liquid, relatively medium viscosity liquid, relatively high viscosity liquid) are sealed in; the three types of liquids with different viscosities have the same amount (weight percentage) of fine particles with the same form (material, size, etc.) added.

Three images (three pseudo blood vessel images) 701, 702, and 703 corresponding to the three liquid storage sections are depicted in the OCTA front image 700. The pseudo blood vessel image 701 is an image caused by the Brownian motion of particles in a relatively low-viscosity liquid (i.e., an image expressing the change in light scattering due to particles undergoing Brownian motion). The pseudo blood vessel image 702 is an image caused by the Brownian motion of particles in a relatively medium-viscosity liquid (i.e., an image expressing the change in light scattering due to particles undergoing Brownian motion). The pseudo blood vessel image 703 is an image caused by the Brownian motion of particles in a relatively high-viscosity liquid (i.e., an image expressing the change in light scattering due to particles undergoing Brownian motion).

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

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

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

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

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

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

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

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

In the example shown in FIG. 17, some design aspects of the laminate are pre-defined. Examples of such design aspects include the number of layers, the number of liquid storage sections, and the positions of the liquid storage sections.

The design aspects of the liquid storage section may also be set in advance. For example, the form of the liquid storage section (shape, length, diameter, etc.), the liquid material, the liquid viscosity, the microparticle material, the amount of microparticles to be added to the liquid, etc. can be determined in advance.

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

In the laminate manufacturing method of this example, first, a predetermined number of liquid storage sections are created according to the predetermined design specifications (S10). The liquid storage sections are created as described above (see, for example, Figure 8).

Next, the materials for forming the first layer are weighed (S11). In this example, for the first layer, the base material is weighed (S11-1) and the fine particles to be added thereto are weighed (S11-2). This results in a predetermined amount of base material and a predetermined amount of fine particles to be used to form the first layer.

Next, a predetermined amount of the microparticles obtained in step S11-2 is added to the predetermined amount of the base material obtained in step S11-1 (S12).

Next, the base material to which the fine particles have been added in step S12 is stirred, and degassing (degassing) is performed to remove any gas dissolved in the base material (S13). Any known method can be used for stirring and degassing. This removes unnecessary gas from the base material, and disperses the fine particles in the base material.

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

Next, the mixture processed into layers in step S14 is hardened (S15). For this hardening process, for example, a physical hardening method using heat or a chemical hardening method using a specified substance is used. This completes the formation of the first layer.

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

If "No" is selected in step S16, one or more of the predetermined number of liquid storage units created in step S11 are installed in a predefined position on the top surface of the layer formed in the immediately preceding step S15. The process of step S17 is performed only when a liquid storage unit is placed between the layer formed in the immediately preceding step S15 and the layer to be formed immediately thereafter. In other words, if "No" is selected in step S16 and a liquid storage unit is not placed between the layer formed in the immediately preceding step S15 and the layer to be formed immediately thereafter, the process of step S17 is skipped and the process proceeds to step S18. Steps S11 to S15 are then performed again to form the next layer. Also, execution or skipping of step S17 is selected depending on the predetermined installation position of the liquid storage unit.

Steps S11 to S15 and step S17 are repeatedly executed until step S16 is judged as "Yes." In other words, steps S11 to S15 are repeatedly executed the same number of times as the number of layers that is previously set, together with step S17 that is executed as appropriate. This results in a laminate that includes one or more liquid storage sections in a previously set arrangement and has a previously set number of layers stacked on top of each other.

This laminate manufacturing method makes it possible to easily and reliably create a laminate that includes a predetermined number of layers, each with a predetermined characteristic, and a predetermined number of simulated blood vessels. In particular, since the method is configured to harden one layer before moving on to the process of forming the next layer, it is possible to manufacture the desired laminate with high ease and high reliability.

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

The same particles may be used for all layers, or two or more particles may be used separately. It is also possible to form two or more layers having the same scattering properties in succession and treat these two or more layers as a single layer.

The model eye of the exemplary embodiment described above has a laminate including a substrate and multiple layers, but the model eye of other exemplary embodiments may not have multiple layers. Some examples of such model eyes are described below.

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

When the ophthalmic device 1 applies a scan for OCTA to the pseudo fundus 800, the measurement light LS that passes through approximately the center of the objective lens 22 is projected onto the pseudo fundus 800. The ophthalmic device 1 detects the return light of the measurement light LS projected onto the pseudo fundus 800 to construct an OCTA image. Unlike the case where multiple layers 620-1, 620-2, ..., 620-N are provided as in the laminate 600 of the above-mentioned embodiment, in the pseudo fundus 800 of this embodiment, refractive index matching is not performed, so very strong regular reflection occurs. In addition, regular reflection also occurs on the surface of the liquid storage section 830-m (capillary). As described above, the measurement light LS is projected from the front onto the pseudo fundus 800 through the objective center, so OCTA is strongly affected by regular reflection. In other words, the return light of the measurement light LS contains a large regular reflection component. Under such a condition, it is not possible to appropriately grasp the state of Brownian motion in the liquid storage section 830-m. To solve this problem, in this embodiment, diffuse reflection is used to detect the state of Brownian motion in the liquid storage section 830-m. This operation will be explained below with further reference to Figure 18B.

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

By configuring in this manner, it is possible to detect the state of Brownian motion in the liquid storage section 830-m by utilizing the diffuse reflection of the measurement light LS projected at a position outside the liquid storage section 830-m, without projecting the measurement light LS directly onto the liquid storage section 830-m. In other words, the return light of the measurement light LS projected onto the projection area 860 includes the diffuse reflected light that has passed through the liquid storage section 830-m, out of the diffuse reflected light in the projection area 860, and this embodiment can detect the state of Brownian motion in the liquid storage section 830-m based on this diffuse reflected light.

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 a fixing unit 840A. Reference numeral 850A indicates an observation range. When the pseudo fundus 800A is used to evaluate the OCTA function, the projection area 860A of the measurement light LS overlaps with the liquid storage unit 830A, so that the return light of the measurement light LS is mixed with strong regular reflection, and the state of Brownian motion in the liquid storage unit 830A cannot be suitably detected. Although it is possible to adopt such a configuration, it is preferable to additionally provide a means for preventing regular reflection. For example, it is possible to apply a coating for suppressing regular reflection to the surface of the liquid storage unit 830A and/or the upper surface of the substrate 810, to provide an optical filter that reduces or blocks regular reflection, or to perform a filter process that reduces or removes the regular reflection component of the return light.

Figure 19 shows another aspect of the pseudo fundus in which the liquid storage section is arranged at a position outside the projection area of the measurement light LS. The simulated fundus 900 includes a substrate 910. On the substrate 910, M liquid storage sections 930-1, 930-2, ..., 930-M are arranged to form an M-sided polygon (M is an integer of 1 or more). The M liquid storage sections 930-1, 930-2, ..., 930-M are fixed to the upper surface of the substrate 910 by M fixing sections 940-1, 940-2, ..., 940-M. Each liquid storage section 930-m may have a configuration similar to that of the liquid storage section 630-m described above. Reference numeral 950 indicates the observation range. Reference numeral 960 indicates the projection area of the measurement light LS. With this aspect as well, it is possible to detect the state of Brownian motion in the liquid storage section 930-m by utilizing diffuse reflection without being affected by strong regular reflection.

<Characteristics, Function, Effects>
With respect to the exemplary aspects disclosed above, some features, some operations, and some advantages will be described.

Some exemplary embodiments of the eye model (500) are used in the field of ophthalmology and include a liquid storage section (630-m) that stores a liquid in which fine particles are suspended.

With a model eye having such a configuration, it is possible to detect the state of Brownian motion of particles floating in the liquid stored in the liquid storage section by OCTA. Therefore, the model eye of the exemplary embodiment can be used as a phantom for OCTA.

In addition, according to the exemplary embodiment of the model eye, since Brownian motion is used to generate an OCTA signal, a liquid flow generating device for simulating blood flow is not required. Therefore, the structure of the exemplary embodiment of the model eye is simple and compact. The liquid storage section may have a shape that mimics a blood vessel, and may include, for example, a tubular body (640) that contains a liquid to which fine particles have been added.

In order to further improve the actions and effects of such exemplary embodiments and/or to obtain other actions and effects, it is possible to optionally adopt various configurations and features described below.

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

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

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

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

In some exemplary embodiments, the eye model (500) may further include a laminate (600) consisting of multiple layers (620-1 to 620-N). Since such an eye model has a structure similar to the human fundus, it can be used as a phantom for OCT structural imaging in addition to being used as a phantom for OCTA.

The liquid storage section (630-m) in the exemplary embodiment of the model eye (500) may be disposed in any manner. For example, as shown in FIG. 10(A), the liquid storage section may be disposed inside any of the multiple layers. Also, as shown in FIG. 10(B), a liquid storage section may be provided in each of at least two of the multiple layers. Also, as shown in FIG. 10(C) and FIG. 10(D), the liquid storage section may be disposed across at least two of the multiple layers. These are presented as non-limiting examples that mimic the vascular distribution pattern in the human fundus.

In some exemplary embodiments, a portion of the liquid storage section may be exposed from the laminate. In the example shown in FIG. 11, both ends of the liquid storage section are exposed from the laminate, but the present invention is not limited to such an embodiment. For example, a configuration in which only one end of the liquid storage section is exposed from the laminate, or a configuration in which the center of the liquid storage section is exposed from the laminate, may be adopted. In general, any portion of the liquid storage section may be exposed from the laminate. With such a configuration, the liquid storage section can be viewed from the outside, which facilitates the task of placing the model eye on the ophthalmic device and also facilitates the task of determining the area to which the OCT scan is applied.

In some exemplary embodiments, a configuration that allows the orientation of the liquid storage unit to be changed can be adopted. In the example shown in FIG. 12, the liquid storage unit is configured to be rotatable in a plane perpendicular to the direction (axial direction) in which the layers of the laminate are stacked (a plane that substantially corresponds to the xy plane when the OCT scan is applied by the ophthalmic device 1), but the manner in which the orientation of the liquid storage unit can be changed is not limited to this. For example, the plane to which the rotational orbit of the liquid storage unit belongs is not limited to the xy plane, and may be any plane. In addition, the rotation direction of the liquid storage unit is not limited to a single direction, and may be capable of rotation in any two of the following two modes: rotation in the xy plane, rotation in the yz plane, and rotation in the zx plane.

Some exemplary aspects of the model eye (500) may further include a first temperature control unit (470) for maintaining a constant temperature of the liquid in the liquid storage unit (630-m). With this configuration, the state of Brownian motion of particles floating in the liquid can be stabilized, and the performance as a phantom can be stabilized. This can improve the accuracy, precision, and reproducibility of the performance evaluation of the OCTA function. Note that, although the temperature control unit 470 in the example shown in FIG. 14 is expressed 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.

Some exemplary embodiments of the model eye (500) may further include a second temperature control unit (470) for changing the temperature of the liquid in the liquid storage unit (630-m). With this configuration, the state of Brownian motion of the particles floating in the liquid can be adjusted so as to achieve the desired function as a phantom. Note that, although the temperature control unit 470 in the example shown in FIG. 14 is expressed as an element separate from the model eye 500, at least a portion 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.

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

It should be noted that any of the items disclosed in the above exemplary embodiments can be combined with the exemplary embodiment of the model eye.

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 the eye. The model eye (500) is used to evaluate the data acquisition unit. The model eye includes a liquid storage unit (630-m) that stores a liquid in which fine particles are suspended.

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

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 data acquired from the model eye by the data acquisition unit.

According to this aspect, the ophthalmic device can perform performance evaluation by itself, so that, for example, adjustment and calibration can be easily performed after installation in a medical institution, etc. Furthermore, by configuring the device to automatically perform periodic quality evaluation and send the evaluation results to a maintenance server, it becomes possible to provide a remote maintenance service. The methods of using the evaluation results are not limited to these.

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

According to this aspect, it is possible to facilitate the evaluation of an ophthalmic device using a model eye. In other words, in order to properly perform an evaluation using a model eye, it is necessary to accurately position the model eye relative to the optical system of the ophthalmic device to be evaluated, but with the ophthalmic device of this aspect, the cumbersome task of manually adjusting the position of the model eye is not required.

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

In addition, this embodiment makes it possible to evaluate not only the imaging performance and measurement performance of the ophthalmic device, but also the alignment performance.

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

It should be noted that any of the items disclosed in the above exemplary embodiments can be combined with the exemplary embodiment of the ophthalmic device.

The above disclosure is merely an example of the implementation of this invention. Anyone who wishes to implement this invention may make any modifications (omissions, substitutions, additions, etc.) within the scope of the gist of this invention.

1 Ophthalmic device 500 Model eye 630-m (m=1, . . ., M; M is an integer of 1 or more) Liquid storage unit

Claims (11)

A model eye for use in the field of ophthalmology,
a liquid storage section that stores a liquid in which fine particles are suspended;
and a laminate consisting of a plurality of layers,
The liquid storage section is disposed across at least two layers of the plurality of layers.
Model eye. A model eye for use in the field of ophthalmology,
a liquid storage section that stores a liquid in which fine particles are suspended;
and a laminate consisting of a plurality of layers,
A portion of the liquid storage section is exposed from the stack.
Model eye. A plurality of said liquid storage units are included.
The eye model according to claim 1 or 2 . The liquids having different viscosities are stored in the liquid storage units.
The eye model according to claim 3 . The liquids in which the particles of different sizes are suspended are stored in the liquid storage units.
The eye model according to claim 3 or 4 . The liquid storage unit includes a tubular body in which the liquid is sealed.
The model eye according to any one of claims 1 to 5 . a data acquisition unit for optically acquiring eye data;
and a model eye for evaluation of the data acquisition unit,
The model eye is
a liquid storage section that stores a liquid in which fine particles are suspended;
and a laminate consisting of a plurality of layers,
The liquid storage section is disposed across at least two layers of the plurality of layers.
Ophthalmic equipment. a data acquisition unit for optically acquiring eye data;
and a model eye for evaluation of the data acquisition unit,
The model eye is
a liquid storage section that stores a liquid in which fine particles are suspended;
and a laminate consisting of a plurality of layers,
A portion of the liquid storage section is exposed from the stack.
Ophthalmic equipment. Further comprising an evaluation unit that generates evaluation information based on the data acquired from the model eye by the data acquisition unit.
9. An ophthalmic apparatus according to claim 7 or 8 . 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.
10. The ophthalmic device of claim 9 . 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.
11. An ophthalmic apparatus according to claim 9 or 10 .

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