Ophthalmologic apparatus
By designing an ophthalmic device that integrates optical systems, alignment systems and evaluation units, the complex problems of model glasses installation and alignment in the prior art are solved, and more accurate and reliable equipment evaluation is achieved.
Patent Information
- Application Number
- JP2025002055
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-01-07
- Publication Date
- 2025-03-21
- Estimated Expiration
- 2039-12-27
AI Technical Summary
Prior art When using model glasses for ophthalmic equipment evaluation, it is necessary to manually adjust the position of the model glasses, resulting in a complex and inaccurate evaluation process.
An ophthalmic device including an optical system, an alignment system and an evaluation unit is designed that automatically aligns the optical system with the model glasses through the alignment system and generates evaluation information.
The installation and alignment process of model glasses is simplified, the accuracy and reliability of evaluation is improved, and the complexity of manual adjustment is reduced.
Smart Images

Figure 2025039681000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to an ophthalmic device. [Background technology]
[0002] Various devices are used in ophthalmic examinations, typically including imaging devices and measuring devices. Imaging devices are ophthalmic devices for acquiring images of the subject's eye, examples of which include optical coherence tomography (OCT) devices, fundus cameras, and scanning laser ophthalmoscopes (SLO). Measuring devices are ophthalmic devices for measuring the characteristics of the subject's eye, examples of which include eye refraction measuring devices (refractometers, keratometers), tonometers, specular microscopes, and wavefront analyzers.
[0003] Such ophthalmic devices are precision instruments, and in order to fully utilize their performance, they require adjustment and calibration based on rigorous evaluation. There are various methods for evaluating ophthalmic devices, but a method using a model eye is widely used (for example, see Patent Document 1).
[0004] In order to properly perform evaluations using a model eye, it is necessary to accurately position the model eye with respect to the optical system of the ophthalmic device being evaluated; however, this requires extremely cumbersome work, such as manually adjusting the position of the model eye. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] JP 2012-110575 A Summary of the Invention [Problem to be solved by the invention]
[0006] An object of the present invention is to facilitate evaluation of an ophthalmic apparatus using a model eye. [Means for solving the problem]
[0007] Some exemplary aspects are ophthalmic devices that include an optical system for acquiring eye data, an alignment system that aligns the optical system with a model eye placed at a predetermined position, and an evaluation unit that generates evaluation information based on data of the model eye acquired by the optical system after the alignment.
[0008] In some exemplary embodiments, the ophthalmic device may further include a chin rest on which the subject's chin is placed, and a first attachment attachable to the chin rest, and the model eye may be attached to the first attachment.
[0009] In some exemplary embodiments, the ophthalmic device may further include a forehead rest against which the subject's forehead is placed, and a second attachment attachable to the forehead rest, and the model eye may be attached to the second attachment.
[0010] In some exemplary aspects, the alignment system may include a moving mechanism that moves the optical system, a first imaging unit that photographs the model eye from two or more different directions, and a first processing unit that controls the moving mechanism based on the two or more images of the model eye acquired by the first imaging unit.
[0011] In some exemplary aspects, the model eye may include a cornea portion corresponding to the cornea, and an iris portion corresponding to the iris and forming an opening corresponding to a pupil. The entrance pupil of the opening may be disposed at a position approximately 3.06 mm away from the cornea portion. The diameter of the opening may be set to a value within a range of 2 to 10 mm. The infrared light reflectance of the iris portion may be set to a value within a range of 2.0 to 2.5 percent. The first image capturing unit may have sensitivity to infrared wavelengths. The first processing unit may be configured to identify a pupil region in each of the two or more images, calculate a three-dimensional movement amount of the optical system based on the identified two or more pupil regions, and control the movement mechanism based on the three-dimensional movement amount.
[0012] In some exemplary aspects, the alignment system may include a moving mechanism that moves the optical system, a projection unit that projects a light beam onto the model eye, a second imaging unit that photographs the model eye, and a second processing unit that controls the moving mechanism based on an image acquired by the second imaging unit.
[0013] In some exemplary embodiments, the model eye may include a cornea portion corresponding to a cornea. The cornea portion may have a radius of curvature of approximately 7.7 millimeters. The projection unit may include a first projection unit that projects a light beam from the front onto the model eye. The second processing unit may be configured to identify a reflection image of the light beam by the cornea portion in an image acquired by the second imaging unit, and to control the moving mechanism based on the identified reflection image.
[0014] In some exemplary aspects, the model eye may include a cornea portion corresponding to a cornea. The radius of curvature of the cornea portion may be approximately 7.7 millimeters. The projection unit may include a second projection unit that projects a light beam obliquely onto the model eye. The second image capture unit may include a line sensor or an area sensor that is arranged in a direction approximately symmetrical to the projection direction of the light beam with respect to the optical axis of the optical system. The second processing unit may be configured to control the movement mechanism based on a position of a light receiving element of the line sensor or the area sensor that detects the reflected light of the light beam by the cornea portion.
[0015] In some exemplary embodiments, the eye model may include a left eye model corresponding to a left eye and a right eye model corresponding to a right eye, and the ophthalmic device may further include a third attachment for placing the left eye model in a first position and placing the right eye model in a second position.
[0016] In some example embodiments, the evaluator may be configured to generate first evaluation information indicative of a quality of data acquired by the optical system.
[0017] In some example embodiments, the evaluator may be configured to generate second evaluation information indicative of a quality of the alignment performed by the alignment system.
[0018] Some exemplary aspects are a method for evaluating the performance of an ophthalmic device including an optical system for acquiring eye data, comprising placing a model eye at a predetermined position, aligning the optical system with the model eye placed at the predetermined position, and generating evaluation information based on data of the model eye acquired by the optical system after the alignment.
[0019] In some exemplary embodiments, the step of placing the model eye in the predetermined position may include the steps of attaching a first attachment to a chin rest of the ophthalmic device and attaching the model eye to the first attachment.
[0020] In some exemplary embodiments, the step of placing the model eye in the predetermined position may include the steps of attaching a second attachment to a forehead rest of the ophthalmic device and attaching the model eye to the second attachment.
[0021] In some exemplary embodiments, the alignment step may include photographing the model eye from two or more different directions, and moving the optical system based on two or more images of the model eye obtained by photographing from the two or more directions.
[0022] In some exemplary embodiments, the model eye may include a cornea portion corresponding to the cornea, and an iris portion corresponding to the iris and forming an opening corresponding to a pupil. The entrance pupil of the opening may be disposed at a position approximately 3.06 mm away from the cornea portion. The diameter of the opening may be set to a value within a range of 2 to 10 mm. The infrared light reflectance of the iris portion may be set to a value within a range of 2.0 to 2.5 percent. The step of photographing the model eye from two or more different directions may be performed by photographing with sensitivity to infrared wavelengths. The step of moving the optical system based on the two or more images may include a step of identifying a pupil region in each of the two or more images, a step of calculating a three-dimensional movement amount of the optical system based on the identified two or more pupil regions, and a step of moving the optical system based on the three-dimensional movement amount.
[0023] In some exemplary aspects, the alignment step may include projecting a light beam onto the model eye, photographing the model eye, and moving the optical system based on the image obtained by photographing the model eye.
[0024] In some exemplary embodiments, the eye model may include a cornea portion corresponding to a cornea. The radius of curvature of the cornea portion may be approximately 7.7 millimeters. The step of projecting the light beam may include a step of projecting the light beam from the front onto the eye model. The step of moving the optical system may include a step of identifying a reflection image of the light beam by the cornea portion in the image acquired by photographing the eye model, and a step of moving the optical system based on the identified reflection image.
[0025] In some exemplary embodiments, the model eye may include a cornea portion corresponding to a cornea. The radius of curvature of the cornea portion may be approximately 7.7 millimeters. The step of projecting the light beam may include a step of projecting the light beam obliquely onto the model eye. The step of photographing the model eye may include a step of detecting reflected light of the light beam by the cornea portion using a line sensor or an area sensor arranged in a direction approximately symmetrical to the projection direction of the light beam with respect to the optical axis of the optical system. The step of moving the optical system may include a step of moving the optical system based on the position of a light receiving element of the line sensor or the area sensor that detects the reflected light.
[0026] In some exemplary embodiments, the model eye may include a left model eye corresponding to a left eye and a right model eye corresponding to a right eye. The step of placing the model eye at the predetermined position may include the steps of attaching a third attachment to the ophthalmic device, attaching the left model eye to the third attachment to place the left model eye in a first position, and attaching the right model eye to the third attachment to place the right model eye in a second position.
[0027] In some example embodiments, generating the evaluation information may include generating first evaluation information indicative of a quality of data acquired by the optical system.
[0028] In some example embodiments, generating the evaluation information may include generating second evaluation information indicative of a quality of the alignment performed by the alignment system.
[0029] Some exemplary aspects are programs that cause an ophthalmic device to execute the evaluation method of any of the aspects.
[0030] Some exemplary aspects are a computer-readable non-transitory recording medium having a program according to any of the aspects recorded thereon. Effect of the Invention
[0031] According to some exemplary aspects, it is possible to facilitate evaluation of an ophthalmic apparatus using an eye model. [Brief description of the drawings]
[0032] [Figure 1] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. [Diagram 2] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. [Figure 3A] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. [Figure 3B] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. [Figure 4A] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. [Figure 4B] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. [Diagram 5] 1 is a schematic diagram illustrating an example of a configuration of a model eye for evaluating an ophthalmic apparatus according to an exemplary aspect of an embodiment. [Figure 6] 1 is a schematic diagram illustrating an example of a configuration for mounting a model eye on an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. [Figure 7A] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. [Figure 7B] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. [Figure 8] 11 is a flowchart illustrating an example of an operation that can be performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Several exemplary aspects of an ophthalmic apparatus according to an embodiment, an evaluation method thereof, a program, and a recording medium will be described. In the exemplary aspects described below in detail, an ophthalmic apparatus that combines an optical coherence tomography (OCT) device and a fundus camera is taken up, but the ophthalmic apparatus according to the embodiment is not limited to this, and may be any ophthalmic apparatus having a function of inspecting (photographing, measuring, etc.) an eye and an alignment function.
[0034] The OCT device included in the ophthalmic apparatus of the exemplary embodiment described in detail below employs spectral domain OCT, but the type of OCT applicable to the ophthalmic apparatus of the embodiment is not limited to spectral domain OCT and may be, for example, swept source OCT.
[0035] Spectral domain OCT is a technique in which light from a low-coherence light source is split into measurement light and reference light, 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 performing a Fourier transform or the like on the detected spectral distribution.
[0036] In contrast, swept-source OCT is a technique in which light from a tunable light source is split into measurement light and reference light, the return light of the measurement light from the test object is superimposed on the reference light to generate interference light, this interference light is detected by a photodetector such as a balanced photodiode, and an image is formed by performing a Fourier transform or the like on the detection data collected in response to the wavelength sweep and the measurement light scan.
[0037] In this way, spectral domain OCT is an OCT method that acquires the spectral distribution by spatial division, while swept source OCT is an OCT method that acquires the spectral distribution by time division.
[0038] In this specification, unless otherwise specified, there is no distinction between "image data" and "image" which is visualized information based on the image data. Furthermore, unless otherwise specified, there is no distinction between a part or tissue of the subject's eye and a corresponding part of the model eye. Similarly, there is no distinction between a part or tissue of the subject's eye and an image in which it is visualized, and there is no distinction between a part of the model eye and an image in which it is visualized.
[0039] <composition> An exemplary embodiment of an ophthalmic apparatus is shown in Fig. 1. The ophthalmic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic and control unit 200. The fundus camera unit 2 is provided with an optical system and 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 is provided with 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.
[0040] The fundus camera unit 2 is provided with a chin rest and a forehead rest for holding the face of the subject. The chin rest and the forehead rest correspond to the face holder 450 shown in Figs. 4A and 4B. A drive mechanism and an arithmetic control circuit are housed in the base 310. An optical system is housed in a housing 320 provided on the base 310. An objective lens 22 is housed in a lens housing section 330 provided to protrude from the front surface of the housing 320.
[0041] Furthermore, the ophthalmic apparatus 1 includes a lens unit for switching the part to which OCT is applied. Specifically, the ophthalmic apparatus 1 includes an anterior segment OCT attachment 400 for applying OCT to the anterior segment. The anterior segment OCT attachment 400 may be configured similarly to the optical unit disclosed in, for example, JP 2015-160103 A.
[0042] 1, the anterior segment OCT attachment 400 can be placed between the objective lens 22 and the subject's eye E. When the anterior segment OCT attachment 400 is placed in the optical path, the ophthalmic apparatus 1 can apply an OCT scan to the anterior segment. On the other hand, when the anterior segment OCT attachment 400 is retracted from the optical path, the ophthalmic apparatus 1 can apply an OCT scan to the posterior segment. The anterior segment OCT attachment 400 is moved manually or automatically.
[0043] In some embodiments, 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, and may be any site of the eye. Note that the configuration for switching the site to which the OCT scan is applied is not limited to such an attachment, and it is also possible to adopt, for example, a configuration having a lens that can be moved along the optical path, or a configuration having a lens that can be inserted and removed from the optical path.
[0044] At least a portion of the functionality of the elements disclosed herein is implemented using circuitry or processing circuitry. The circuitry or processing circuitry may be a general purpose processor, a special purpose processor, an integrated circuit, a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), a field programmable gate array (FPGA), or a combination of a programmable logic device (PLC) and a programmable logic device (PGD)), configured and / or programmed to perform at least a portion of the functionality disclosed. The term "circuitry", "unit", "means" or the like includes any of the above-mentioned circuitry, including a transistor and / or other circuitry, a processor, a processor array, a 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, a unit, a means, or the like is hardware that performs at least some of the disclosed functions or is hardware that is programmed to perform at least some of the disclosed functions. The hardware may be hardware disclosed herein or may be known hardware that is programmed and / or configured to perform at least some of the described functions. In the case where the hardware is a processor that can be considered to be a type of circuitry, a circuitry, a unit, a means, or the like is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.
[0045] Fundus Camera Unit 2 The fundus camera unit 2 is provided with an optical system for photographing the fundus Ef (and the anterior segment) of the subject's eye E. The acquired digital image of the fundus Ef (called a fundus image, fundus photograph, etc.) is generally a front image such as an observed image or a photographed image. The observed image is obtained by capturing a moving image using near-infrared light. The photographed image is a still image captured using a flash light in the visible range.
[0046] The fundus camera unit 2 includes an illumination optical system 10 and an imaging optical system 30. The illumination optical system 10 irradiates illumination light onto the subject's eye E. The imaging optical system 30 detects return light of the illumination light irradiated onto the subject's eye E. 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. 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.
[0047] 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 light cut filter 14 to become near-infrared light. The observation illumination light is then focused once near the photographing light source 15, reflected by the mirror 16, and passes through the relay lens system 17, the relay lens 18, the diaphragm 19, and the relay lens system 20 to be guided to the aperture mirror 21. The observation illumination light is then reflected at the periphery (area surrounding 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.
[0048] The light (imaging illumination light) output from the imaging light source 15 is irradiated onto the fundus Ef through the same path as the observation illumination light. The return light of the imaging illumination light from the subject's eye E is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by a mirror 36, and is imaged by an imaging lens 37 on the light receiving surface of an image sensor 38.
[0049] A liquid crystal display (LCD) 39 displays a fixation target (fixation target image). A part of the light beam output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, passes through the photographing focusing lens 31 and the dichroic mirror 55, and passes through the hole of the aperture mirror 21. The light beam that passes through the hole of the aperture mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef. The fixation target is typically used to guide and fix the gaze. The direction to which the gaze of the subject's eye E is guided (and fixed), that is, the direction to which the subject's eye E is encouraged to fixate, is called the fixation position.
[0050] The fixation position can be changed by changing the display position of the fixation target image on the screen of the LCD 39. Examples of fixation positions include a fixation position for acquiring an image centered on the macula, a fixation position for acquiring an image centered on the optic disc, a fixation position for acquiring an image centered on a position between the macula and the optic disc (center of the fundus), and a fixation position for acquiring an image of a site far away from the macula (periphery of the fundus).
[0051] A graphical user interface (GUI) or the like for specifying at least one of such typical fixation positions can be provided. Also, a GUI or the like for manually moving the fixation position (display position of the fixation target) can be provided. Also, a configuration for automatically setting the fixation position can be applied.
[0052] The configuration for presenting a fixation target with a changeable fixation position to the subject's eye E is not limited to a display device such as an LCD. For example, a device (fixation matrix) in which a plurality of light-emitting units (such as light-emitting diodes) are arranged in a matrix can be used instead of a display device. In this case, the fixation position of the subject's eye E based on the fixation target can be changed by selectively turning on the plurality of light-emitting units. As another example, a fixation target with a changeable fixation position can be generated by a device having one or more movable light-emitting units.
[0053] The alignment optical system 50 generates an alignment index used for aligning the optical system with respect to the subject's eye E. Alignment light output from a light-emitting diode (LED) 51 passes through an aperture 52, an aperture 53, and a relay lens 54, is reflected by a dichroic mirror 55, passes through the hole of 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).
[0054] It should be noted that the alignment method applicable to the embodiments 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 onto the cornea from the front, or a method using an optical lever that projects a light beam onto the cornea from an oblique angle and detects the corneal reflected light in the opposite direction.
[0055] The focusing optical system 60 generates a split index used for focus adjustment of the subject's eye E. 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 focusing 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 disposed on the illumination optical path. The focusing light output from the LED 61 passes through the relay lens 62, is split 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 focusing 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 passes through the same path as the return light of the alignment light and is guided to the image sensor 35. Manual focusing or autofocusing can be performed based on the received light image (split target image).
[0056] Diopter correction lenses 70 and 71 can be selectively inserted into the photographing optical path between the aperture mirror 21 and the dichroic mirror 55. The diopter correction lens 70 is a plus lens (convex lens) for correcting strong hyperopia. The diopter correction lens 71 is a minus lens (concave lens) for correcting strong myopia.
[0057] The dichroic mirror 46 combines the optical path for fundus imaging and the optical path for OCT (measurement arm). The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for fundus imaging. 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 this order from the OCT unit 100 side.
[0058] The retroreflector 41 is movable along the optical path of the measurement light LS incident thereon, thereby changing the length of the measurement arm. The change in the measurement arm length is used, for example, to correct the optical path length according to the axial length of the eye, adjust the interference state, and so on.
[0059] The dispersion compensation member 42, together with a dispersion compensation member 113 (described later) disposed in the reference arm, acts to match the dispersion characteristics of the measurement light LS with the dispersion characteristics of the reference light LR.
[0060] The OCT focusing lens 43 is moved along the measurement arm to adjust the focus of the measurement arm. The movement of the imaging focusing lens 31, the movement of the focus optical system 60, and the movement of the OCT focusing lens 43 can be controlled in a coordinated manner.
[0061] The optical scanner 44 is disposed substantially at a position optically conjugate with the pupil of the subject's eye E. The optical scanner 44 deflects the measurement light LS guided by the measurement arm. The optical scanner 44 is, for example, a 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 ±x directions and a one-dimensional scanner (y-scanner) for deflecting the measurement light in ±y directions. In this case, for example, either one of these one-dimensional scanners is disposed at a position optically conjugate with the pupil, or a position optically conjugate with the pupil is disposed between these one-dimensional scanners.
[0062] <OCT Unit 100> The exemplary OCT unit 100 shown in FIG. 2 is provided with an optical system for performing spectral domain OCT. This optical system includes an interference optical system. This interference optical system splits light from a low-coherence light source (broadband light source) into measurement light and reference light, and generates interference light by superimposing the return light of the measurement light projected onto the subject's eye E and the reference light 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.
[0063] The light source unit 101 outputs wideband low coherence light L0. The low coherence light L0 includes, for example, a wavelength band in the near infrared region (approximately 800 nm to 900 nm) and has a temporal coherence length of approximately several tens of micrometers. The low coherence light L0 may be near infrared light having a central wavelength of, for example, approximately 1040 to 1060 nm that is not visible to the human eye. The light source unit 101 includes a light output device such as a superluminescent diode (SLD), an LED, or a semiconductor optical amplifier (SOA).
[0064] When swept-source OCT is employed, the light source unit includes, for example, a near-infrared tunable laser that changes the wavelength of emitted light at high speed.
[0065] Low-coherence light L0 output from light source unit 101 is guided by optical fiber 102 to polarization controller 103, where its polarization state is adjusted. The light L0 whose polarization state has been adjusted is guided by optical fiber 104 to fiber coupler 105, where it is split into measurement light LS and reference light LR. The optical path that guides the measurement light LS is called a measurement arm, etc., and the optical path that guides the reference light LR is called a reference arm, etc.
[0066] The reference light LR generated by the fiber coupler 105 is guided by the optical fiber 110 to the collimator 111, 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 that of the measurement light LS. The dispersion compensation member 113 acts, together with the dispersion compensation member 42 arranged in the measurement arm, 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 correcting the optical path length according to the axial length of the eye, adjusting the interference state, and the like.
[0067] The reference light LR that has passed through the retroreflector 114 passes through the dispersion compensation member 113 and the optical path length correction member 112, is converted from a parallel beam to a focused beam by the collimator 116, and enters an optical fiber 117. The reference light LR that has entered the optical fiber 117 is guided to a polarization controller 118 where its polarization state is adjusted, is guided through an optical fiber 119 to an attenuator 120 where its light amount is adjusted, and is guided through an optical fiber 121 to a fiber coupler 122.
[0068] On the other hand, the measurement light LS generated by the fiber coupler 105 is guided through the optical fiber 127 to the collimator lens unit 40, where it is converted into a parallel beam, passes through the retroreflector 41, the dispersion compensation member 42, the OCT focusing lens 43, the optical scanner 44, and the relay lens 45, is reflected by the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the subject's eye E. The measurement light LS is scattered and reflected at various depth positions in the subject's eye E. 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.
[0069] The fiber coupler 122 superimposes the measurement light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121 to generate an interference light LC.
[0070] The interference light LC generated by the fiber coupler 122 is guided to the spectrometer 130 through the optical fiber 129. The spectrometer 130 converts the incident interference light LC into a parallel beam 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 a plurality of spectral components of the interference light LC to generate an electrical signal (detection signal). The generated detection signal is sent to the arithmetic and control unit 200.
[0071] In addition, when swept-source OCT is adopted, interference light generated by superimposing measurement light and reference light is branched at a predetermined branching ratio (for example, 1:1) to generate a pair of interference light, and the generated pair of interference light is guided to a photodetector. The photodetector includes, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that detect the pair of interference light, 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 a data acquisition system (DAQ). A clock is supplied to the data acquisition system from the light source unit. The clock is generated in the light source unit in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength-tunable light source. For example, the light source unit branches light of each output wavelength to generate two branched lights, optically delays one of the branched lights, combines the branched 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 by this sampling is used for processing such as image construction.
[0072] The ophthalmic device 1 shown in Fig. 1 and Fig. 2 is provided with both an element for changing the measurement arm length (e.g., a retroreflector 41) and an element for changing the reference arm length (e.g., a retroreflector 114 or a reference mirror), but in some exemplary embodiments, only one of these elements is provided. The coherence gate position is changed by relatively changing the measurement arm length and the reference arm length (i.e., by changing the optical path length difference between the measurement arm and the reference arm). The element for changing the optical path length difference is not limited to the elements disclosed in this embodiment, and may be any element (optical member, mechanism, etc.).
[0073] <Arithmetic control unit 200> The arithmetic control unit 200 controls each part of the ophthalmic 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.
[0074] The arithmetic control unit 200 includes, for example, a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, a communication interface, etc. Various computer programs are stored in a storage device such as a hard disk drive. The arithmetic control unit 200 may also include an operation device, an input device, a display device, etc.
[0075] As shown in FIG. 3A, the user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes, for example, the display device 3. The operation unit 242 includes various operation devices and input devices. The user interface 240 may include a device that integrates a display function and an operation function, such as a touch panel. An ophthalmic apparatus according to some exemplary embodiments may not include at least a part of the user interface. For example, the display device and / or the operation device may be peripheral devices of the ophthalmic apparatus.
[0076] <Anterior Eye Camera 300> The anterior eye camera 300 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.
[0077] In this embodiment, two anterior eye cameras 300A and 300B are provided, but the number of anterior eye cameras 300 may be any number equal to or greater than 1. Considering the calculation process described below, a configuration capable of photographing the anterior eye from two different directions is sufficient (but is not limited to this). Alternatively, a movable anterior eye camera 300 may be provided to sequentially photograph the anterior eye from two or more different positions.
[0078] In this embodiment, two anterior eye cameras 300 are provided separately from the illumination optical system 10 and the photographing optical system 30, and for example, the anterior eye can be photographed using the photographing optical system 30. That is, one of the two or more anterior eye cameras 300 may be the photographing optical system 30. The anterior eye camera 300 according to this embodiment may be capable of photographing the anterior eye from two (or more) different directions.
[0079] A configuration for illuminating the anterior eye may be provided. The anterior eye illumination means includes, for example, one or more light sources. Typically, at least one light source (e.g., an infrared light source) can be provided near each of the two or more anterior eye cameras 300.
[0080] Typically, the anterior eye photographing from two or more different directions is performed substantially simultaneously. "Substantially simultaneously" means that the timing of the anterior eye photographing from two or more different directions is simultaneous, and also means that, for example, a timing difference that can ignore eye movement is intervened. By such substantially simultaneous photographing, it is possible to photograph the anterior eye from two or more different directions when the subject's eye E is in substantially the same position and orientation.
[0081] 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 realized, for example, by controlling the timing of starting photographing by two or more anterior eye cameras 300 to coincide, or by controlling the frame rate and the timing of acquiring each frame. On the other hand, in the case of still image photographing, the anterior eye photographing can be realized substantially simultaneously by controlling the timing of photographing by two or more anterior eye cameras 300 to coincide.
[0082] When photographing a model eye as described below, it is not necessary to perform such substantially simultaneous photographing.
[0083] <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 an arithmetic control unit 200, for example.
[0084] <Control unit 210> The control unit 210 includes a processor, and controls each unit of the ophthalmologic apparatus 1. The control unit 210 includes a main control unit 211 and a storage unit 212.
[0085] <Main control unit 211> The main controller 211 includes a processor and controls each element (including the elements shown in FIGS. 1 to 3B) of the ophthalmologic apparatus 1. The main controller 211 is realized, for example, by cooperation between hardware including a circuit and control software.
[0086] The photographing focusing lens 31 arranged in the photographing optical path and the focus optical system 60 arranged in the illumination optical path are moved integrally or in cooperation with each other by a photographing focusing drive unit (not shown) under the control of the main control unit 211. The retroreflector 41 arranged 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 arranged 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 photographing focusing lens 31 and the focus optical system 60. The retroreflector 114 arranged 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 exemplified here typically includes an actuator such as a pulse motor that operates under the control of the main control unit 211. The optical scanner 44 arranged 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.
[0087] The moving mechanism 150, for example, moves at least the fundus camera unit 2 three-dimensionally. In a typical example, the moving mechanism 150 includes an x-stage movable in ±x directions (left and right directions), an x-moving mechanism for moving the x-stage, a y-stage movable in ±y directions (up and down directions), a y-moving mechanism for moving the y-stage, a z-stage movable in ±z directions (depth direction), and a z-moving mechanism for moving the z-stage. Each of these moving mechanisms includes an actuator such as a pulse motor that operates under the control of the main controller 211.
[0088] <Storage section 212> The storage unit 212 stores various types of data. Examples of data stored in the storage unit 212 include image data of an OCT image, image data of a fundus image, 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.
[0089] <Image forming unit 220> The image forming unit 220 forms OCT image data based on the data acquired by the spectrometer 130. The image forming unit 220 includes a processor. The image forming unit 220 is realized, for example, by cooperation between hardware including a circuit and image forming software.
[0090] The image forming unit 220 forms cross-sectional image data based on the data acquired by the spectroscope 130. This image forming process includes signal processing such as sampling (A / D conversion), noise removal (noise reduction), filtering, and fast Fourier transform (FFT), similar to conventional spectral domain OCT.
[0091] The image data formed by the image forming unit 220 is a data set including a group of image data (a group of A-scan image data) formed by imaging the reflection intensity profiles in multiple A-lines (scan lines along the z-direction) arranged in the area where the OCT scan was applied.
[0092] The image data formed by the image forming unit 220 is, for example, one or more B-scan image data, or stack data formed by embedding a plurality of B-scan image data in a single three-dimensional coordinate system. The image forming unit 220 can also perform a voxelization process on the stack data to construct volume data (voxel data). The stack data and volume data are typical examples of three-dimensional image data expressed in a three-dimensional coordinate system.
[0093] The image forming unit 220 can process the three-dimensional image data. For example, the image forming unit 220 can apply rendering to the three-dimensional image data to construct new image data. Rendering methods include volume rendering, maximum intensity projection (MIP), minimum intensity projection (MIP), surface rendering, and multiplanar reconstruction (MPR). The image forming unit 220 can also construct projection data by projecting the three-dimensional image data in the z direction (A-line direction, depth direction). The image forming unit 220 can also construct a shadowgram by projecting a 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.
[0094] 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 observed image data or captured image data. The data processing unit 230 includes a processor. The data processing unit 230 is realized, for example, by cooperation between hardware including a circuit and data processing software.
[0095] Next, a 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.
[0096] <Model eyes 500> The model eye 500 is attached to the face holder 450 via the 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 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.
[0097] 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 to the lens) corresponding to the crystalline lens, a vitreous portion 560 corresponding to the vitreous body, and a fundus portion 570 corresponding to the fundus. The number of elements included in the model eye 500 (e.g., the number of lenses) is arbitrary.
[0098] The iris portion 520 forms an opening 540 corresponding to a 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 crystalline lens portion 550. The substance provided in the space between the cornea portion 510 and the crystalline lens portion 550 is arbitrary, and may be, for example, any gas, any liquid, or any solid.
[0099] The fundus 570 has a layered structure corresponding to the fundus of a human eye. For example, the fundus 570 has one or more layers corresponding to any tissue of the fundus of a human eye. 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 570 may be equivalent to the thickness and refractive index of one or more corresponding tissues. The shape of the fundus 570 is not limited to 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 570 may also have a structure corresponding to any part or tissue of a human eye. For example, the fundus 570 may have a structure corresponding to a macular region, a structure corresponding to an optic disc, a structure corresponding to a blood vessel, and the like. The fundus 570 may also have a structure corresponding to any disease, any pathological condition, or any lesion, such as a structure corresponding to age-related macular degeneration (AMD) (drusen, etc.), a structure corresponding to retinal detachment, a structure corresponding to bleeding, a structure corresponding to a tumor, or a structure corresponding to atrophy.
[0100] The parameter values of the eye model 500 may be designed to be equivalent or similar to those of a human eye. The parameter values of the eye model 500 may be obtained, for example, from a standard eye model or clinical data. The standard eye model may include a Gullstrand eye model, a Navarro eye model, a Liou-Brennan eye model, a Badal eye model, an Arizona eye model, an Indiana eye model, any standardized eye model, and any model eye equivalent to any of these. The eye model 500 may be designed based on an eye having a disease such as high myopia. The eye model 500 may have a structure equivalent to any disease, any pathological condition, or any lesion. For example, the eye model 500 may have a structure equivalent to any corneal disease, any lens disease, or the like. The eye model 500 may have a structure equivalent to an artificial object. For example, the eye model 500 may have an intraocular lens (IOL) or a structure equivalent thereto.
[0101] The distance between the center position of the front surface of the cornea portion 510 (the position corresponding to the corneal apex) and the front surface of the fundus portion 570 may be designed based on the axial length of the human eye. The focal length of the cornea portion 510, the lens portion 550, and the vitreous portion 560 as a whole may be designed to be equal to the focal length of the human eye. For example, the model may have a means (for example, 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, it is possible to perform imaging and measurement evaluation of an eye with a long axial length.
[0102] The reflectance of the front surface (surface on the cornea portion 510 side) 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 an infrared wavelength. Similarly, the front surface of the cornea portion 510 can also be designed to be equivalent to that of the human eye. Furthermore, the model eye 500 may be designed so that the entrance pupil of the iris portion 520 (variable portion 530, opening 540) is located at a position equivalent to that of the entrance pupil of the iris of the human eye.
[0103] In order to prevent multiple reflections of the light used by the data acquisition optical system 410 (in this embodiment, the measurement light LS) and the light used by the alignment system 420 (in this embodiment, the wavelength band (e.g., infrared wavelength) detected by the anterior eye camera 300) within the model eye 500, it is possible to provide an anti-reflective coating on the lenses, etc., or to apply anti-reflective paint to the internal components.
[0104] When performing alignment using two or more anterior eye cameras 300 (cameras sensitive to infrared wavelengths) as in the ophthalmologic apparatus 1 of this embodiment, 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 mm away from the cornea portion 510. The diameter of the opening 540 may be set to a value within a range of 2 to 10 mm. Furthermore, the infrared light reflectance of the iris portion 520 (variable portion 530) may be set to a value within a range of 2.0 to 2.5 percent. With such a design, it becomes possible to perform alignment with respect to the model eye 500 using the opening 540 as a reference, similar to the case of performing alignment using the pupil of a human eye as a reference.
[0105] Even when another alignment method is used, the parameter values of the model eye 500 are set according to the method. For example, when alignment is performed using a corneal reflection image (Purkinje image), the radius of curvature of the cornea portion 510 (the radius of curvature of the 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.
[0106] <Face holder 450, attachment 460> The face holder 450 is a member that holds the subject's face 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 (comes into contact) with the forehead rest.
[0107] The attachment 460 is a member for mounting 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.
[0108] 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 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.
[0109] An example of the model eye 500 and the attachment 460 is shown in FIG. 6. In this example, the attachment 460 is attached to the chin rest 451 of the face holder 450. More specifically, the attachment part 461 at the lower end of the attachment 460 is attached to the upper surface of the stand 451 on which the chin of the subject is placed. The stand 451 and the attachment part 461 may be attached in any manner, for example, by screwing or fitting. Furthermore, a left model eye 500L corresponding to the left eye and a right model eye 500R corresponding to the right eye are attached to the model eye stand 462 at the upper end of the attachment 460. The model eyes 500L and 500R may be attached in any manner, for example, by screwing or fitting. According to such a manner, the model eye 500 can be placed in the same position as the actual subject's eye, so that the alignment function of the ophthalmic apparatus 1 can be used to align the data acquisition optical system 410 with respect to the model eye 500.
[0110] In another exemplary embodiment, the model eye 500 may be configured to be attached to the forehead rest 452 via an attachment 460. In this example, the attachment 460 is attached, for example, at its upper end portion to the forehead rest 452, and the model eye 500 is attached to its lower end portion. The manner of attachment is arbitrary.
[0111] 6, two model eyes 500L and 500R are (indirectly) attached to the ophthalmic apparatus 1, but any number of model eyes may be attached to the ophthalmic apparatus 1. Typically, one or two model eyes are attached to the ophthalmic apparatus 1.
[0112] 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 of the model eye 500 in the same manner as acquiring data of the subject's eye E. For example, the ophthalmic apparatus 1 of this embodiment can apply OCT scanning to the model eye 500. In addition, the ophthalmic apparatus 1 of this embodiment can photograph the fundus 570 of the model eye 500 using the fundus camera unit 2.
[0113] <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. The predetermined position at which the model eye 500 is placed is, for example, the position of the model eye 500L (and / or 500R) shown in FIG.
[0114] In this embodiment, the alignment system 420 includes two anterior eye cameras 300, a processing unit 430, and a moving mechanism 150. As described above, the two anterior eye cameras 300 include imaging elements sensitive to infrared wavelengths, and are configured to capture images of the model eye 500 placed at a predetermined position from two different directions. The moving mechanism 150 is configured to move the data acquisition optical system 410.
[0115] Processing section 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 .
[0116] The processing unit 430 is configured to execute the processing described in, for example, Japanese Patent Application Laid-Open No. 2013-248376 filed by the present applicant. More specifically, the processing unit 430 first analyzes each of the two images of the model eye 500 captured by the two anterior eye cameras 300 to identify the pupil region in each image.
[0117] Next, the processing unit 430 calculates the amount of three-dimensional movement of the data acquisition optical system 410 based on the two pupil regions identified from the two images. Trigonometry is used for this calculation.
[0118] Furthermore, the processing unit 430 controls the moving mechanism 150 based on the calculated three-dimensional movement amount. More specifically, the processing unit 430 controls the moving mechanism 150 so as 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).
[0119] For details of the processing performed by the processing unit 430, please refer to a series of documents by the present applicant related to inventions using two or more anterior eye cameras, such as Japanese Patent Application Laid-Open No. 2013-248376 and Japanese Patent Application Laid-Open No. 2014-113385. The processing unit 430 is realized by, for example, the main control unit 211 and the data processing unit 230.
[0120] The ophthalmologic apparatus 1 of this embodiment may use the alignment optical system 50 to align the data acquisition optical system 410 with the model eye 500. In this case, auto-alignment using an alignment index (described above) is applied to the model eye 500.
[0121] Some exemplary embodiments of the ophthalmic apparatus may be capable of performing XY alignment and / or Z alignment described in Japanese Patent Application Laid-Open No. 2018-164616 filed by the present applicant. XY alignment is an alignment method using a corneal reflection image (Purkinje image), and Z alignment is an alignment method using an optical lever.
[0122] 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, for example, the configuration shown in Fig. 7A can be adopted instead of the configuration shown in Fig. 3B. In the configuration example shown in Fig. 7A, the alignment system 420 shown in Fig. 3B is replaced with an alignment system 420A. Among the elements shown in Fig. 7A, the same elements as those in Fig. 3B are indicated by the same reference numerals, and unless otherwise specified, the description of those elements will not be repeated.
[0123] The model eye 500 of this example includes at least a cornea portion (510) corresponding to the cornea, and the radius of curvature of this cornea portion is set to approximately 7.7 mm.
[0124] The alignment system 420A includes a projection section 421A, an imaging section 422A, a processing section 430A, and a moving mechanism 150.
[0125] The projection unit 421A projects a light beam onto the model eye 500. In particular, the projection unit 421A projects a light beam onto the model eye 500 from the front. Typically, the projection unit 421A is configured to project a parallel light beam onto the model eye 500 through a part of the optical path of the data acquisition optical system 410. As a result, a bright spot image (corneal reflection image, Purkinje image) is formed on the cornea of the model eye 500.
[0126] The photographing unit 422A photographs the model eye 500 in a state where a light beam is projected by the projection unit 421A. A corneal reflection image is depicted in the image of the model eye 500 obtained by the photographing unit 422A. The image of the model eye 500 obtained by the photographing unit 422A is input to the processing unit 430A. The photographing unit 422A is an area sensor in which multiple light receiving elements (photoelectric conversion elements) are two-dimensionally arranged.
[0127] 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 (for example, edge detection).
[0128] Furthermore, the processing unit 430A controls the moving mechanism 150 based on the corneal reflection image identified from the image of the model eye 500. For example, the processing unit 430A calculates the deviation of the corneal reflection image from a predetermined reference position (for example, a position corresponding to the optical axis of the data acquisition optical system 410), and controls the moving mechanism 150 to cancel this deviation (so that the corneal reflection image is located 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.
[0129] For details of the processing performed by the processing unit 430A, see, for example, Japanese Patent Application Publication No. 2018-164616 and Japanese Patent Application Publication No. 10-024019. The processing unit 430A is realized by, for example, the main control unit 211 and the data processing unit 230.
[0130] When applying the technique using an optical lever to the alignment of the data acquisition optical system 410 with respect to the model eye 500, for example, the configuration shown in Fig. 7B can be adopted instead of the configuration shown in Fig. 3B. In the configuration example shown in Fig. 7B, the alignment system 420 shown in Fig. 3B is replaced with an alignment system 420B. Among the elements shown in Fig. 7B, the same elements as those in Fig. 3B are indicated by the same reference numerals, and unless otherwise specified, the description of those elements will not be repeated.
[0131] The model eye 500 of this example includes at least a cornea portion (510) corresponding to the cornea, and the radius of curvature of this cornea portion is set to approximately 7.7 mm.
[0132] The alignment system 420B includes a projection section 421B, an imaging section 422B, a processing section 430B, and a moving mechanism 150.
[0133] The projection unit 421B projects a light beam onto the model eye 500. In particular, the projection unit 421B projects a light beam obliquely onto the model eye 500. Typically, the projection unit 421B is configured to project a parallel light beam onto the model eye 500 from a position outside the optical path of the data acquisition optical system 410. As a result, the light beam projected onto the cornea of the model eye 500 is reflected by the surface of the cornea.
[0134] The photographing unit 422B is disposed in a direction approximately symmetrical to the direction of projection 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 disposed in positions approximately symmetrical to each other with respect to the optical axis of the data acquisition optical system 410. Typically, the photographing unit 422B is 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) of the light beam emitted from the projection unit 421B by the cornea 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 all-black image. On the other hand, when the corneal reflected light is detected by the image capturing section 422B, a bright spot image is included in the image obtained by the image capturing section 422B. The image obtained by the image capturing section 422B is input to the processing section 430B.
[0135] The processing unit 430B analyzes the image acquired by the photographing unit 422B to determine the presence or absence of a bright spot image, 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 obtains the deviation of the position of the bright spot image from a predetermined reference position. In other words, the processing unit 430B identifies the address of the light receiving element that detected the corneal reflected light among the multiple light receiving elements of the photographing unit 422B, and obtains the deviation between the address of this light receiving element and a predetermined reference address.
[0136] Furthermore, the processing unit 430B controls the moving mechanism 150 based on the deviation thus identified. For example, the processing unit 430B controls the moving mechanism 150 so as to cancel this deviation (so that the corneal reflected light is detected by the light receiving element at the reference address). 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.
[0137] For details of the processing performed by the processing unit 430B, see, for example, Japanese Patent Application Publication No. 2018-164616 and Japanese Patent Application Publication No. 2015-146859. The processing unit 430B is realized by, for example, the main control unit 211 and the data processing unit 230.
[0138] <Evaluation Section 440> After the alignment is performed by the alignment system 420 (420A, 420B), the data acquisition optical system 410 acquires data of the model eye 500. For example, the ophthalmologic apparatus 1 aligns the data acquisition optical system 410 with respect to the model eye 500 by the alignment system 420, and then applies an OCT scan to the model eye 500 by the data acquisition optical system 410.
[0139] The evaluation unit 440 generates evaluation information based on data of the model eye 500 acquired after alignment. For example, the evaluation unit 440 may be configured to generate data quality evaluation information indicating the quality of 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 alignment performed by the alignment system.
[0140] 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 ophthalmologic apparatus 1 applies an OCT scan to the fundus 570 by the data acquisition optical system 410. The image forming unit 220 forms an image of the fundus 570 from the OCT data acquired by the data acquisition optical system 410. The evaluation unit 440, for example, compares the formed image of the fundus 570 with a predetermined evaluation image. The 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.
[0141] As another example of generating the data quality evaluation information, the evaluation unit 440 can obtain the value of a predetermined evaluation parameter representing the 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.
[0142] When generating the alignment quality evaluation information, the evaluation unit 440 executes a predetermined alignment quality evaluation process. For example, the evaluation unit 440 can evaluate the alignment quality based on the time required for alignment, the processing contents, and the results.
[0143] In some exemplary embodiments, the evaluation unit 440 can generate the alignment quality evaluation information based on the length of time (alignment time) from the start of alignment to reaching a suitable alignment state (e.g., a state in which the alignment error is within a predetermined range). For example, the evaluation unit 440 can compare the alignment time with a predetermined threshold, and evaluate the alignment time as "low quality" if it exceeds the threshold, and evaluate the alignment time as "high quality" if it is equal to or less than the threshold. Alternatively, the evaluation unit 440 can be configured to determine which of a plurality of predetermined ranges (high quality range, acceptable range, poor range) the alignment time belongs to, and generate the alignment quality evaluation information based on the range to which the alignment time belongs.
[0144] In some exemplary embodiments, 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 alignment until a suitable alignment state is reached. The alignment operation is, for example, the number of times the processing unit 430 (430A, 430B) processes 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.
[0145] In some exemplary embodiments, the evaluation unit 440 can generate the alignment quality evaluation information based on the result of the processing performed by the alignment system 420 (420A, 420B). For example, the evaluation unit 440 can determine an alignment state (e.g., an alignment error) reached by the alignment system 420 performing an alignment operation for a predetermined time, and generate the alignment quality evaluation information based on the 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 the alignment quality evaluation information based on the range to which the alignment error belongs.
[0146] <Operation> 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.
[0147] First, the model eye 500 is placed (S1). In this embodiment, for example, the two model eyes 500L and 500R are attached to the chin rest 451 using the attachment 460. Note that it may be possible to directly attach the model eye 500 to the chin rest 451, directly or indirectly attach the model eye 500 to the forehead rest 452, or directly or indirectly attach the model eye 500 to another location on the ophthalmologic apparatus 1.
[0148] After the eye model 500 is attached to the ophthalmic apparatus 1, the ophthalmic apparatus 1 starts alignment of the eye model 500 (S2). This alignment is performed using, for example, any of the alignment system 420 in Fig. 3B, the alignment system 420A in Fig. 7A, and the alignment system 420B in Fig. 7B.
[0149] The alignment may be performed, for example, until a suitable alignment state is achieved, or the alignment may be performed for a predetermined time, or the alignment may be performed until a predetermined number of iterations of the alignment operation are reached.
[0150] When the alignment is completed (S3), the ophthalmologic apparatus 1 applies an OCT scan to the model eye 500 (S4). This OCT scan may be, for example, an OCT scan of the fundus portion 570, or an OCT scan of a portion corresponding to the anterior segment (one or more of the cornea portion 510, the iris portion 520, the variable portion 530, the aperture 540, and the lens portion 550).
[0151] The ophthalmic apparatus 1 generates evaluation information by the evaluation unit 440 (S5). For example, the ophthalmic apparatus 1 can generate data quality evaluation information by the evaluation unit 440 based on the OCT data acquired by the OCT scan in step S4. Also, the ophthalmic apparatus 1 can generate alignment quality evaluation information by the evaluation unit 440 based on the data obtained about the alignment in step S3.
[0152] The evaluation information generated in step S5 is displayed, for example, on the display unit 241. The evaluation information generated in step S5 is also transmitted from the ophthalmologic apparatus 1 to an external device. The evaluation information generated in step S5 is also recorded on a recording medium. This is the end of this operation example.
[0153] <effect> Some features, actions, and effects of the ophthalmologic apparatus 1 according to this embodiment will be described.
[0154] The ophthalmic apparatus 1 includes a data acquisition optical system 410, an alignment system 420 (420A, 420B), and an evaluation unit 440. The data acquisition optical system 410 includes an optical system for acquiring eye data. The alignment system 420 is configured to align the data acquisition optical system 410 with a model eye 500 installed at a predetermined position. The evaluation unit 440 is configured to generate evaluation information based on data of the model eye 500 acquired by the data acquisition optical system 410 after alignment by the alignment system 420 (420A, 420B).
[0155] According to the present aspect configured in this manner, it is possible to facilitate the evaluation work of an ophthalmic device using a model eye. That is, in order to properly perform an evaluation using the model eye, it is necessary to accurately position the model eye with respect to the optical system of the ophthalmic device to be evaluated, but according to the ophthalmic device of the present aspect, it is not necessary to manually adjust the position of the model eye, which is a cumbersome task.
[0156] According to the present 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 the present aspect, it is possible to improve the accuracy, precision, and reproducibility of the evaluation of the ophthalmic device.
[0157] Furthermore, according to this aspect, it is possible to evaluate not only the imaging performance and measurement performance of the ophthalmic apparatus, but also the alignment performance.
[0158] The ophthalmologic apparatus 1 may further include a chin rest 451 on which the chin of the subject is placed, and an attachment 460 that can be attached to the chin rest 451. Furthermore, the model eye 500 is attached to the attachment 460.
[0159] According to the present embodiment configured in this manner, the model eye 500 can be placed in the same position as the test eye that will actually be photographed and measured by the ophthalmic apparatus, so that the alignment function of the ophthalmic apparatus can be applied to the model eye 500 as is.
[0160] The ophthalmologic apparatus 1 may further include a forehead rest 452 on which the subject's forehead is placed, and an attachment (not shown) that can be attached to the forehead rest 452. Furthermore, the model eye 500 is attached to this attachment.
[0161] According to the present embodiment configured in this manner, the model eye 500 can be placed in the same position as the test eye that will actually be photographed and measured by the ophthalmic apparatus, so that the alignment function of the ophthalmic apparatus can be applied to the model eye 500 as is.
[0162] The alignment system of the ophthalmic apparatus 1 may be an alignment system 420. The alignment system 420 includes a moving mechanism 150, two (or more) anterior eye cameras 300, and a processing unit 430. The moving mechanism 150 is configured to move the data acquisition optical system 410. The two (or more) anterior eye cameras 300 are configured to capture images of the model eye 500 from two (or more) different directions. The processing unit 430 is configured to control the moving mechanism 150 based on two (or more) images of the model eye 500 captured by the two (or more) anterior eye cameras 300.
[0163] According to the present embodiment configured as described above, it is possible to align the data acquisition optical system 410 with respect to the model eye 500 by utilizing an alignment method using two (or more) anterior eye cameras 300. In other words, it is possible to apply the present embodiment to an ophthalmic device having an alignment function using two (or more) anterior eye segments.
[0164] In the present embodiment configured as described above, the model eye 500 may include a cornea portion 510 corresponding to the cornea, and an iris portion 520 (and a variable portion 530) corresponding to the iris and forming an opening 540 corresponding to the pupil. Furthermore, the entrance pupil of the opening 540 may be disposed at a position approximately 3.06 mm away from the cornea portion 510, and the diameter of the opening 540 may be set to a value within a range of 2 to 10 mm. Furthermore, the infrared light reflectance of the iris portion 520 (and the variable portion 530) may be set to a value within a range of 2.0 to 2.5 percent. In addition, the two (or more) anterior eye cameras 300 may have sensitivity to infrared wavelengths. Furthermore, the processing unit 430 may be configured to specify a pupil region in each of the two (or more) images acquired by the two (or more) anterior eye cameras 300, calculate a three-dimensional movement amount of the data acquisition optical system 410 based on the specified two or more pupil regions, and control the movement mechanism 150 based on the three-dimensional movement amount.
[0165] According to this aspect configured as above, it is possible to execute an alignment operation in the same manner as alignment for the human eye, using an eye model having parameter values equivalent to those of the human eye.
[0166] The alignment system of the ophthalmologic apparatus 1 may be the alignment system 420A or 420B. The alignment system 420A or 420B includes a moving mechanism 150, a projection unit 421A or 421B, an image capturing unit 422A or 422B, and a processing unit 430A or 430B. The moving mechanism 150 is configured to move the data acquisition optical system 410. The projection unit 421A (421B) is configured to project a light beam onto the model eye 500. The image capturing unit 422A (422B) is configured to capture the image of the model eye 500. The processing unit 430A (430B) is configured to control the moving mechanism 150 based on an image captured by the image capturing unit 422A (or 422B).
[0167] According to this aspect configured as above, it is possible to align the data acquisition optical system 410 with the model eye 500 by utilizing an alignment method of projecting a light beam onto an object (eye to be inspected, model eye). In other words, this aspect can be applied to an ophthalmic device having an alignment function of projecting a light beam onto an object (eye to be inspected, model eye).
[0168] The alignment system of the ophthalmologic apparatus 1 may be the alignment system 420A. In this case, the model eye 500 includes a cornea portion 510 corresponding to the cornea. The radius of curvature of the cornea portion 510 is designed to be approximately 7.7 millimeters. The alignment system 420A includes a moving mechanism 150, a projection unit 421A, an imaging unit 422A, and a processing unit 430A. The moving mechanism 150 is configured to move the data acquisition optical system 410. The projection unit 421A is configured to project a light beam onto the model eye 500 from the front. The imaging unit 422A is configured to image the model eye 500. Typically, the imaging unit 422A is configured to image the model eye 500 from the front, and the projection unit 421A and the imaging unit 422A are arranged coaxially. The processing unit 430A is configured to identify a reflection image of the light beam by the cornea unit 510 in the image acquired by the imaging unit 422A, and to control the moving mechanism 150 based on the identified reflection image.
[0169] According to this embodiment configured as described above, it is possible to align the data acquisition optical system 410 with the model eye 500 by using an alignment method using a corneal reflection image (Purkinje image). In other words, this embodiment can be applied to an ophthalmic apparatus having an alignment function using a corneal reflection image (Purkinje image).
[0170] The alignment system of the ophthalmologic apparatus 1 may be the alignment system 420B. In this case, the model eye 500 includes a cornea portion 510 equivalent to the cornea. The radius of curvature of the cornea portion 510 is designed to be approximately 7.7 millimeters. The alignment system 420B includes a moving mechanism 150, a projection unit 421B, an image capturing unit 422B, and a processing unit 430B. The moving mechanism 150 is configured to move the data acquisition optical system 410. The projection unit 421B is configured to project a light beam obliquely onto the model eye 500. The image capturing unit 422B includes a line sensor or an area sensor arranged in a direction approximately symmetrical to the projection direction of the light beam with respect to the optical axis of the data acquisition optical system 410. Typically, the projection unit 421B and the line sensor (area sensor) are arranged in positions approximately symmetrical to the optical axis of the data acquisition optical system 410. The processing unit 430B is configured to control the moving mechanism 150 based on the position of the light receiving element of the line sensor (area sensor) that detects the reflected light of the light beam by the cornea portion 510.
[0171] According to this aspect configured as above, it is possible to use an alignment method using an optical lever to align the data acquisition optical system 410 with the model eye 500. In other words, this aspect can be applied to an ophthalmic apparatus having an alignment function using an optical lever.
[0172] By applying an alignment method using two (or more) anterior eye cameras 300, it is possible to perform three-dimensional alignment of the data acquisition optical system 410 with respect to the model eye 500. In addition, by combining an alignment method using a corneal reflection image (Purkinje image) with an alignment method using an optical lever, it is possible to perform three-dimensional alignment of the data acquisition optical system 410 with respect to the model eye 500.
[0173] The model eye 500 may include a left model eye 500L corresponding to the left eye and a right model eye 500R corresponding to the right eye. Furthermore, the ophthalmologic apparatus 1 may further include an attachment 460 for placing the left model eye 500L at a first position and placing the right model eye at a second position (see FIG. 6).
[0174] According to the present embodiment configured as described above, it is possible to apply alignment of the data acquisition optical system 410 to both the left model eye 500L and the right test eye 500R. Furthermore, it is possible to perform evaluation based on the left model eye 500L and evaluation based on the right test eye 500R individually or comprehensively. It is also possible to perform performance evaluation of the function of switching the target of the data acquisition optical system 410 between the left eye and the right eye.
[0175] The evaluation unit 440 may be configured to generate data quality evaluation information indicating the quality of 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 alignment performed by the alignment system 420 (420A, 420B). The types of evaluation information are not limited to these.
[0176] The ophthalmic apparatus 1 of this embodiment can provide the following exemplary evaluation method. This evaluation method is a method for evaluating the performance of an ophthalmic apparatus including an optical system for acquiring eye data.
[0177] According to some exemplary aspects, an ophthalmic device evaluation method includes first placing a model eye at a predetermined position, then aligning an optical system with the model eye placed at the predetermined position, and then generating evaluation information based on data of the model eye acquired by the optical system after the alignment.
[0178] In some exemplary embodiments, placing the eye model in a predetermined position may include attaching a first attachment to a chin rest of the ophthalmic device and attaching the eye model to the first attachment.
[0179] In some exemplary embodiments, placing the eye model in a predetermined position may include attaching a second attachment to a forehead rest of the ophthalmic device and attaching the eye model to the second attachment.
[0180] In some exemplary embodiments, the alignment step may include photographing the model eye from two or more different directions and moving the optical system based on two or more images of the model eye obtained by photographing from the two or more directions.
[0181] In some exemplary embodiments, the model eye may include a cornea portion corresponding to the cornea, and an iris portion corresponding to the iris and forming an opening corresponding to the pupil. The entrance pupil of the opening may be located at a position approximately 3.06 mm away from the cornea portion. The diameter of the opening may be set to a value within a range of 2 to 10 mm. The infrared light reflectance of the iris portion may be set to a value within a range of 2.0 to 2.5 percent. Furthermore, the step of photographing the model eye from two or more different directions may include photographing with sensitivity to infrared wavelengths. The step of moving the optical system based on the two or more images may include a step of identifying a pupil region in each of the two or more images, a step of calculating a three-dimensional movement amount of the optical system based on the identified two or more pupil regions, and a step of moving the optical system based on the three-dimensional movement amount.
[0182] In some exemplary aspects, the alignment step may include projecting a light beam onto a model eye, photographing the model eye, and moving the optical system based on the image obtained by photographing the model eye.
[0183] In some exemplary embodiments, the eye model may include a cornea portion corresponding to a cornea. The radius of curvature of the cornea portion may be approximately 7.7 millimeters. Furthermore, projecting the light beam may include projecting the light beam from the front onto the eye model. Moving the optical system may include identifying a reflection image of the light beam by the cornea portion in an image acquired by photographing the eye model, and moving the optical system based on the identified reflection image.
[0184] In some exemplary embodiments, the model eye may include a cornea portion corresponding to the cornea. The radius of curvature of the cornea portion may be approximately 7.7 millimeters. Furthermore, the step of projecting the light beam may include a step of projecting the light beam obliquely onto the model eye. The step of photographing the model eye may include a step of detecting reflected light of the light beam by the cornea portion using a line sensor or an area sensor arranged in a direction approximately symmetrical to the projection direction of the light beam with respect to the optical axis of the optical system. The step of moving the optical system may include a step of moving the optical system based on the position of the light receiving element of the line sensor or area sensor that detects the reflected light.
[0185] In some exemplary embodiments, the eye model may include a left eye model corresponding to the left eye and a right eye model corresponding to the right eye. Additionally, placing the eye model in a predetermined position may include attaching a third attachment to the ophthalmic device, attaching the left eye model to the third attachment to place the left eye model in a first position, and attaching the right eye model to the third attachment to place the right eye model in a second position.
[0186] In some example embodiments, generating the evaluation information may include generating first evaluation information indicative of a quality of data acquired by the optical system.
[0187] In some example embodiments, generating the evaluation information may include generating second evaluation information indicative of a quality of the alignment performed by the alignment system.
[0188] In addition, any of the matters (configurations, elements, processing, operations, actions, functions, etc.) described in the above-mentioned exemplary embodiments or any publicly known matters can be combined with any of the above-mentioned evaluation methods.
[0189] It is possible to configure a program that causes an ophthalmic device (including a computer) to execute such an evaluation method. This program may include, for example, any of the above-mentioned programs for operating the ophthalmic device 1 of the exemplary embodiment.
[0190] It is also possible to create a computer-readable non-transitory recording medium having such a program recorded therein. This non-transitory recording medium may be in any form, and examples of such a recording medium include a magnetic disk, an optical disk, a magneto-optical disk, and a semiconductor memory.
[0191] The above-described embodiments are merely examples of the implementation of the present invention. Anyone who wishes to implement the present invention may make any modifications (omissions, substitutions, additions, etc.) within the scope of the gist of the present invention. [Explanation of symbols]
[0192] 1 Ophthalmology equipment 150 Moving mechanism 300, 300A, 300B Anterior Eye Camera 410 Data Acquisition Optical System 420, 420A, 420B Alignment System 421A, 421B projection section 422A, 422B Photography Department 430, 430A, 430B Processing section 440 Evaluation Department 450 Face holder 451 Chin rest 452 Forehead protector 460 Attachment 500, 500L, 500R model eyes 510 Cornea 520 Iris 570 Fundus
Claims
[Claim 1] an optical system for acquiring eye data; an attachment to which a left model eye corresponding to a left eye and a right model eye corresponding to a right eye are attached; an evaluation unit that performs a performance evaluation of a function of switching an object from which data is acquired by the optical system between the left model eye and the right model eye; 13. An ophthalmic device comprising:
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