Ophthalmic examination system, ophthalmic examination device control program

Abstract

To shorten the examination time. [Solution] The ophthalmic examination device of the present disclosure is an ophthalmic examination device that photographs the fundus of an eye under examination based on information regarding the pupil diameter of the eye under examination, and when performing a first photograph and a second photograph performed consecutively after the first photograph, the first photograph is performed when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a first value, and the second photograph is performed when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a second value which is less than the first value.

Description

Technical Field

[0006] , ,

[0001] The disclosure of this specification relates to an ophthalmic examination system and an ophthalmic examination apparatus control program.

Background Art

[0002] As devices for observing a subject eye, OCT (Optical Coherence Tomography), fundus cameras, perimeters, etc. are known. When photographing the fundus of a subject who has not been administered a mydriatic agent with visible light using a fundus camera, it is known that the pupil of the subject eye constricts. When photographing the subject eye of the same subject multiple times, in order to reduce the influence of this pupillary constriction, it is desirable to perform the second and subsequent photographings at a timing when the pupillary constriction has subsided. Patent Document 1 discloses a configuration in which the pupil diameter detected before the first photographing is used as a threshold value, and photographing is awaited until the pupil diameter in the second photographing becomes equal to or greater than the threshold value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, depending on the subject eye, it may take time until the pupillary constriction subsides. If it takes time until the pupillary constriction subsides, the pupil diameter in the second photographing will not become equal to or greater than the threshold value, and it will take time until photographing starts. As a result, the examination time may become longer.

[0005] Therefore, an object of the present disclosure is to shorten the examination time.

Means for Solving the Problems

[0006] The ophthalmic examination apparatus of the present disclosure is An ophthalmic examination device that photographs the fundus of an eye under examination based on information regarding the pupil diameter of the eye under examination, When performing a first photograph and a second photograph that is performed immediately after the first photograph, In the first imaging, imaging is performed when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than the first value. In the second imaging procedure, imaging is performed when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a second value which is less than the first value. [Effects of the Invention]

[0007] According to this disclosure, the inspection time can be shortened. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of an ophthalmic examination device according to Embodiment 1. [Figure 2] This figure shows an example of the configuration of an ophthalmic examination system according to Embodiment 1. [Figure 3] This figure shows an example of the processing flow of the ophthalmic examination system according to Embodiment 1. [Figure 4] This figure shows an example of the display screen of the ophthalmic examination system according to Embodiment 1. [Figure 5] This figure shows an example of the display screen of the ophthalmic examination system according to Embodiment 1. [Figure 6] This figure shows an example of the processing flow of the ophthalmic examination system according to Embodiment 1. [Figure 7] This figure shows an example of a method for changing the threshold of the ophthalmic examination system according to Embodiment 1. [Figure 8] This figure shows an example of a method for changing the threshold of the ophthalmic examination system according to Embodiment 1. [Figure 9] This figure shows an example of the processing flow of the ophthalmic examination system according to Embodiment 1. [Figure 10]This figure shows an example of a method for changing the threshold of the ophthalmic examination system according to Embodiment 2. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing will be denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. Furthermore, some components, members, and processes that are not important for explanatory purposes may be omitted from the drawings.

[0010] <Embodiment 1> Figure 1 shows an example of an ophthalmic device according to Embodiment 1. The ophthalmic device according to Embodiment 1 includes a head portion 104 that is movable in the y-axis direction relative to a base 106, and a stage 105 that is movable in the x-axis and z-axis directions. During the examination, the subject places their forehead on a forehead rest 101 and their chin on a chin rest 102 that is movable in the vertical direction. The ophthalmic device according to Embodiment 1 acquires data about the eye being examined via an objective lens 103. In this embodiment, a non-mydriatic ophthalmic imaging device will be described as an example.

[0011] Figure 2 shows an example of the configuration of an ophthalmic examination system according to Embodiment 1. The ophthalmic examination system according to Embodiment 1 includes an ophthalmic examination device 201, a control device 209, and a display unit 210.

[0012] The ophthalmic examination device 201 consists of a measurement optical system for capturing images of the anterior segment Ea of the eye under examination E, and two-dimensional frontal and tomographic images of the fundus Ef of the eye under examination E. A first dichroic mirror 202 and a second dichroic mirror 203, which function as an example of an optical path separator, are positioned on the optical axis L1 of the objective lens 103. These dichroic mirrors branch the optical path from the objective lens 103 into the optical path for the anterior segment observation system (optical axis L2), the optical path for the fundus imaging system (optical axis L3), and the optical path for the OCT optical system (optical axis L5), according to wavelength band.

[0013] On the optical axis L2 in the reflection direction of the second dichroic mirror 203, a lens 220, a prism 221, an aperture 222, a lens 223, and an image sensor 224 are arranged. The image sensor 224 is a monochrome sensor having sensitivity in the infrared region. A front-eye observation system for observing the anterior eye part Ea is configured by these optical members and the like arranged on the optical axis L2. Further, a front-eye observation light source 225 is arranged near the objective lens 103. The front-eye observation light source 225 of the present embodiment illuminates the anterior eye part of the subject eye E using infrared light.

[0014] The image sensor 224 is connected to the control device 209. The control device 209 can generate a front-eye observation image based on the signal output by the image sensor 224, and output it to the display unit 210 or store it in the storage unit 211. On the optical axis L3 in the transmission direction of the second dichroic mirror 203, a perforated mirror 231, a photographing aperture 232, a focus lens 233, an imaging lens 234, a third dichroic mirror 235, and a fundus camera 236 are arranged.

[0015] The fundus camera 236 includes an image sensor 2360, an observation monitor 2361, and a photometry unit 2362 that performs photometry processing on the output from the image sensor 2360. The perforated mirror 231 has an opening at the center.

[0016] The focus lens 233 can be moved on the optical axis L3 by a drive unit such as a motor (not shown) controlled by the control device 209. The control device 209 can adjust the focus of the light passing through the optical path of the fundus photographing system by controlling the drive unit to move the focus lens 233 in the optical axis direction. The optical path on the optical axis L3 is branched by the third dichroic mirror 235 into an optical path leading to the image sensor 2360 and an optical path leading to the internal fixation lamp 237 for each wavelength band.

[0017] The image sensor 2360 is positioned in the transmission direction of the third dichroic mirror 235. The image sensor 2360 is sensitive to visible light and infrared light. The image sensor 2360 is a sensor for obtaining a frontal image of the fundus for observing the fundus Ef of the eye under examination and for acquiring a fundus photographic image of the fundus Ef of the eye under examination. The internal fixation lamp 237 is positioned in the reflection direction of the third dichroic mirror 235 and generates visible light to guide the direction of the subject's gaze. In addition, other optical components such as an aperture (not shown) may be provided in the optical path of the fundus photography system to cut off the light beam necessary for fundus photography.

[0018] On the optical axis L4 in the reflection direction of the perforated mirror 231, the corneal baffle 240, relay lens 241, focus indicator unit 242, lens 243, and ring slit 244 are arranged in this order. The corneal baffle 240 has a light-shielding point in the center. The ring slit 244 has a ring-shaped slit opening.

[0019] The focus indicator unit 242 is an optical component that provides an indicator for focusing using the focus lens 233. In this embodiment, as an example of an indicator, it projects a split emission line. The focus indicator unit 242 according to this embodiment has a split indicator member that can move along the optical axis L4 in conjunction with the focus lens 233. The split indicator member is also configured to be inserted into and removed from the optical path of the optical axis L4 by a drive unit such as a motor (not shown) controlled by the control device 209. The split emission line projected by the focus indicator unit 242 passes through the relay lens 241 and is reflected by the perforated mirror 231 towards the second dichroic mirror 203. The split emission line reflected by the perforated mirror 231 is projected onto the fundus Ef of the eye E under examination via the second dichroic mirror 203, the first dichroic mirror 202, and the objective lens 103.

[0020] The control device 209 can calculate the amount of focus shift by detecting the position of the split emission line from the fundus observation image. Also, on the optical axis L4, a lens baffle 245, which is a light-shielding member having a light-shielding point, and a dichroic mirror 246, which has the property of transmitting infrared light and reflecting visible light are arranged. A condenser lens 247 and a white LED light source 248 are arranged in the reflection direction of the dichroic mirror 246. The white LED light source 248 is an imaging light source in which multiple white LEDs that emit visible light are arranged.

[0021] A condenser lens 249 and an infrared LED light source 250 are positioned in the transmission direction of the dichroic mirror 246. The infrared LED light source 250 is an observation light source consisting of multiple infrared LEDs that emit continuous infrared light. The white LED light source 248 and the infrared LED light source 250 are controlled by the control device 209.

[0022] An illumination optical system for illuminating the fundus Ef is formed by the objective lens 103, the dichroic mirror 246, the optical elements between them, and the condenser lenses 247 and 249. Through the illumination optical system, the fundus Ef of the eye under examination can be illuminated by light from a white LED light source 248 or an infrared LED light source 250.

[0023] The drive unit 280 that drives the head and stage includes three motors (not shown) controlled by the control device 209. The control device 209 controls the drive of the drive unit 280, thereby moving the optical head unit 104 and the stage 105 in three dimensions (x, y, z). This allows the control device 209 to align the ophthalmic examination device 201 with respect to the eye E under examination. In this embodiment, the configuration that generates anterior eye observation images of the eye under examination is called the anterior eye observation unit, the configuration that generates fundus observation images is called the fundus observation unit, and the configuration that generates fundus photography images is called the fundus photography unit.

[0024] The control device 209 is, for example, a personal computer. The control device 209 operates as an image processing unit by reading a program stored in a storage unit 211 such as a hard disk, which has an internal CPU (not shown).

[0025] The control device 209 performs functions such as processing image data acquired from the storage unit 211 and generating screens to be displayed by the display unit 210, as well as controlling the ophthalmic examination device 201. The control device 209 also includes an audio output unit 290 for outputting sound. In this embodiment, the control device 209 is configured to have one audio output unit 290, but this is not the only configuration. For example, the ophthalmic examination device 201 may be configured to have one audio output unit 290, or the audio output unit 290 may be provided in both the ophthalmic examination device 201 and the control device 209. Alternatively, the audio output unit 290 may be connected separately to the ophthalmic examination device 201 or the control device 209 to output sound.

[0026] The display unit 210 is, for example, an LCD display connected to a personal computer. The display unit 210 displays various types of information. The display unit 210 receives operation instructions from the examiner via the operation unit 212, which consists of a keyboard and mouse connected to the personal computer. In other words, the display unit 210 functions as a user interface.

[0027] In this embodiment, the control device 209 and the ophthalmic examination device 201 work together to function as a single ophthalmic examination system. The control device 209 generates an ophthalmic image diagnostic report (hereinafter referred to as the report) consisting of images of the eye under examination and image analysis results captured by the ophthalmic examination device 201. The CPU built into the control device 209 may be a GPU or the like. In this embodiment, the control device 209 and the ophthalmic examination device 201 are described as being separate, but this is not the only configuration. For example, the ophthalmic examination device 201 may be configured to include the control device 209.

[0028] Figure 2(b) is a diagram showing a list of the main functions of the control device 209. The control device 209 controls the ophthalmic examination device 201 by the ophthalmic examination device control means 2095 and acquires output images. For example, based on operation instructions from the operation unit 212, it can set shooting conditions such as the gaze guidance direction and shooting range for the ophthalmic examination device 201. The audio output control means 2094 controls the content and volume of the audio output unit 290. The state detection means 2092 includes an alignment state detection means 2100 for detecting the alignment state, an examination state detection means 2101 for detecting the state of the examination, a subject state detection means 2102 for detecting the state of the subject, and a device state detection means 2103 for detecting the state of the ophthalmic examination device 201.

[0029] The alignment state detection means 2100 detects the alignment state, which is the positional relationship between the ophthalmic examination device 201 and the eye under examination E, based on information from the anterior eye observation unit or the fundus observation unit. The control device 209 controls the ophthalmic examination device 201 based on the results of the alignment state detection means 2100. For example, when acquiring an image of the eye under examination, it is desirable that the ophthalmic examination device 201 be in a position suitable for acquiring an image of the eye under examination E. In this embodiment, the control device 209 detects the alignment state based on the anterior eye observation image. Subsequently, based on the detected alignment state, it performs alignment processing to move the chin rest 102, head unit 104, or stage 105 to a position suitable for acquiring an image of the eye under examination E. After that, the control device 209 starts acquiring an image of the eye under examination. The examination state detection means 2101 detects the examination state, for example, before the start of the examination, during eye observation, during acquisition of an image of the eye under examination, etc.

[0030] The voice output control means 2094 controls the output from the voice output unit 290 based on the detection result of the examination status detection means 2101. For example, if the examination status detection means 2101 detects that the acquisition of the subject's eye image has not yet begun, it controls the voice output unit 290 to output "The examination will begin." The subject status detection means 2102 detects the subject's status based on, for example, anterior eye observation images, fundus observation images, and the subject's statements. If the subject status detection means 2102 detects that the subject has kept their eyelids open for a long time based on the anterior eye observation images, it outputs "Please blink" from the voice output unit 290. This output prompts the subject to blink. The device status detection means 2103 detects, for example, the processing load status of the ophthalmic examination device 201. If the device status detection means 2103 determines that the processing load of the ophthalmic device 201 is temporarily high and unsuitable for examination, it outputs "Please wait a moment" from the voice output unit 290.

[0031] The eye image acquisition means 2096 acquires observation images from the anterior eye observation unit and the fundus observation unit, or images captured from the fundus photography unit. Alternatively, it acquires eye images stored in the memory unit 211.

[0032] The illumination light incidence information acquisition means 2099 acquires information (hereinafter referred to as illumination light incidence information) regarding the incidence of illumination light emitted from the illumination optical system to the anterior segment or the fundus to the eye under examination, based on an anterior eye observation image, a fundus observation image, or a fundus photograph.

[0033] The report information generation means 2093 can display each acquired image and analysis result as a report on the display unit 210, or output it to a printing device (not shown).

[0034] The shooting timing determination means 2097 determines the shooting timing based on the detection result of the state detection means 2092. For example, if the subject state detection means 2102 detects that the subject is blinking, it can be determined that shooting is not possible.

[0035] The elapsed time measuring means 2098 measures the desired elapsed time. For example, the elapsed time measuring means 2098 measures the time elapsed since the subject placed their chin on the chin rest 102. If the measured elapsed time is long, the voice output unit 290 outputs the message, "Please take your chin off the chin rest and rest for a while."

[0036] Next, the operation of the control device according to Embodiment 1 will be described based on Figures 3 and 4. Figure 4 is an example of a shooting screen, which is a screen for performing an examination. The ophthalmic examination system of this embodiment can set multiple shooting modes to specify the shooting method. During the examination, the examiner selects a shooting mode, and the ophthalmic examination device 201 acquires data according to the shooting mode. The shooting mode of this embodiment is defined by the shooting method, such as a scan pattern, and the shooting position. Examples of shooting modes include a fundus shooting mode for mainly shooting the fundus, and an anterior eye shooting mode for shooting the anterior segment. Furthermore, by setting multiple shooting modes as a protocol, the shooting modes set in the protocol can be performed consecutively. In this embodiment, it is assumed that a protocol is set to continuously acquire data for both the left and right eyes using the fundus shooting mode. At this time, when the examiner instructs the start of the examination once as a shooting trigger, the ophthalmic examination system of this embodiment first performs fundus photography of the right eye. Subsequently, the head 104 and stage 105 are moved, and fundus photography of the left eye is performed consecutively.

[0037] In step S301, the examiner prepares for the examination. In this embodiment, the examiner presses tab 401, which is for opening the imaging screen, to open the imaging screen 400. At this time, it is assumed that a protocol for performing fundus photography of the left and right eyes in the order of right eye, then left eye is selected by default. In this embodiment, the first shot performed according to the selected protocol is referred to as the first eye shot, and the second shot as the second eye shot. The first and second eye shots may be of the same lateral eye, or they may be of both eyes.

[0038] In step S302, when the examination status detection means 2101 detects that the examination preparation is complete, the voice output control means 2094 outputs a voice message from the voice output unit 290 to notify the subject that the examination has begun. For example, it may output "Please rest your chin and touch your forehead to the surface." At the same time, it may also output a voice message to notify the subject of the examination content. For example, it may output "We will photograph your right and left eyes once each."

[0039] In step S303, the examiner confirms that the subject has placed their chin on the chin rest 102 and their forehead on the forehead rest 101. Then, the examiner presses button 402 to start the examination. In this embodiment, once the examiner starts the examination, the ophthalmic examination device begins observing the anterior segment of the subject's eye using the anterior eye observation unit and observing the fundus of the subject's eye using the fundus observation unit. Subsequently, the ophthalmic examination device displays the anterior eye observation image, which is a two-dimensional frontal image of the anterior segment, in area 403, and the fundus observation image, which is a two-dimensional frontal image of the fundus, in area 404. The ophthalmic examination device also lights up or flashes the internal fixation lamp 237 along with the display. Note that the anterior eye observation image and fundus observation image are not limited to two-dimensional frontal images, as long as they are images suitable for alignment between the ophthalmic examination device 201 and the subject. The subject status detection means 2102 also starts detecting the subject's status. In this embodiment, with the subject resting their chin on the chin rest 102, the ophthalmic examination device control means 2095 moves the chin rest 102, head 104, or stage 105 to perform alignment processing. When it is detected that the anterior segment of the subject's eye can be observed by the anterior eye observation unit, the process proceeds to step S304. Alternatively, if the anterior eye observation unit cannot observe the subject's anterior segment, the examiner moves the chin rest 102, head 104, and stage 105 to a position where the anterior segment of the subject's eye can be observed by the anterior eye observation unit. The examiner can move the chin rest 102 by operating, for example, the button 410 for moving the chin rest. The examiner can also move the stage to a desired position by operating the button 411 for moving the stage 105 or an operating member (not shown). In this embodiment, an operating member displayed on the imaging screen is used to move the chin rest 102, etc., but a configuration using an operating member such as a joystick connected to the ophthalmic examination device 201 may also be used.

[0040] In step S304, the audio output control means 2094 outputs audio from the audio output unit 290 to guide the subject's gaze direction, for example, "Look at the internal fixation light." Then, along with the output of audio by the audio output control means 2094, the alignment process begins.

[0041] In step S305, the alignment state detection means 2100 performs alignment processing and periodically detects the alignment state. The alignment state detection means 2100 may also detect the focus state based on the fundus observation image and adjust the position of the focus lens 233. The alignment state detection means 2100 may also adjust the amount of light emitted from the observation light source 250 so that the fundus observation image is of a brightness suitable for observation during the examination.

[0042] The illumination light incidence information acquisition means 2099 calculates illumination light incidence information (pupil diameter, pupil area, pupil shape, pupil ratio to iris, width between iris edge and pupil edge, pupil ratio to specific area, anterior eye photometric value distribution, fundus photometric value distribution, etc.) based on the observed image. These are just examples of information regarding the pupil diameter of the eye being examined. In this embodiment, the pupil diameter is calculated from the anterior eye observation image as illumination light incidence information. If the shooting timing determination means 2097 determines that shooting is possible using the method described later, the process proceeds to step S306.

[0043] In step S306, the audio output control means 2094 outputs an audio message to notify the subject that the acquisition of fundus images has begun. For example, it may output "Please open your eyes wide. We will start the acquisition."

[0044] In step S307, the ophthalmic device acquires a fundus image of the subject's right eye by performing fundus photography on the subject's right eye. At this time, the pupil diameter of the right eye immediately before the photograph is stored in the memory unit 211. Note that this fundus photography is an example of the first photograph.

[0045] In step S308, the examination status detection means 2101 detects that data acquisition for the right eye has been completed. Subsequently, the voice output control means 2094 outputs a voice message to notify the subject that data acquisition for the right eye has finished and data acquisition for the left eye has begun. For example, it may output, "The examination of the right eye is complete. We will move the device. Please blink."

[0046] In step S309, the ophthalmic device moves the stage 105 to a position suitable for acquiring data from the left eye. At this time, the position of the internal fixation light 237, which guides the subject's gaze, is also moved.

[0047] After the stage 105 is moved in step S309, the process proceeds to step S304, where the same processing as in steps S305 to S307 described above is performed. In S307, the ophthalmic device acquires data of the subject's left eye by performing fundus photography on the subject's left eye. This fundus photography is an example of a second type of photography. At this time, the pupil diameter of the left eye immediately before photography is stored in the memory unit 211. After the fundus photography of the subject's left eye is completed in step S307, the process proceeds to step S310.

[0048] In step S310, the examination status detection means 2101 detects that the acquisition of predetermined data has been completed. The voice output control means 2094 outputs a voice message to notify the subject that the series of examinations has finished. For example, it may output "Shooting is complete. Please wait until instructed." As described above, in the series of examinations, fundus photography of the right eye and fundus photography of the left eye are performed consecutively.

[0049] In step S310, the ophthalmic device displays a screen 500 on the display unit 210 for the examiner to confirm the results, as shown in Figure 5. The examiner checks the acquired data. If, as a result of the check, it is determined that reshooting is necessary, the examiner can perform reshooting in the same shooting mode by operating the operation unit 501 provided for each acquired data. At this time, the audio output control means 2094 may output an audio message to notify the subject that reshooting will be performed. For example, it may output, "We will take another shot. Please rest your chin and forehead. We will take one shot of your left eye."

[0050] Based on Figures 6 and 7, the method by which the imaging timing determination means 2097 determines whether imaging is possible in step S305 will be described. The imaging timing determination means 2097 determines whether imaging is possible when it determines that the positional relationship between the ophthalmic examination device 201 and the eye under examination E is in a position suitable for examination, and that the amount of light necessary to photograph the fundus is entering the eye under examination through the pupil. In this embodiment, one method for determining whether imaging is possible is whether the pupil diameter is greater than a predetermined value. The predetermined value is different for imaging the first eye (right eye) and imaging the second eye (left eye). The predetermined value used for imaging the first eye (right eye) is an example of a first value. The predetermined value used for imaging the second eye (left eye) is an example of a second value. In step S601, alignment is performed so that the positional relationship between the ophthalmic examination device 201 and the eye under examination E is in a position suitable for examination. Various known methods can be used for alignment. Furthermore, if the positional relationship is unsuitable for the examination, the control device 209 may be configured to adjust the position of the ophthalmic examination device 201. Alternatively, the examiner may manually adjust the position of the ophthalmic examination device 201. In this case, it is desirable that the ophthalmic device can notify the examiner of the alignment status in a discernible manner. If the alignment status detection means 2100 detects that the positional relationship between the ophthalmic examination device 201 and the eye E under examination is suitable for the examination, the procedure proceeds to step S602. In step S602, the illumination light incidence information acquisition means 2099 calculates illumination light incidence information. In this embodiment, the pupil diameter is calculated based on the anterior eye observation image as illumination light incidence information. Various known methods can be used to calculate the pupil diameter.

[0051] In step S603, the pupil diameter calculated in step S602 is compared with the threshold. If the pupil diameter calculated in step S602 is greater than or equal to the threshold, it is determined that imaging is possible and the process ends. After completion, the process proceeds to step S306. If the pupil diameter calculated in step S602 is less than the threshold, it is determined that imaging is not possible and the process proceeds to step S604.

[0052] In step S604, the ophthalmic device changes the threshold based on the measurement result of the elapsed time measurement means 2098. Generally, when visible light is incident on an eye that has not been administered a pupil-dilating agent, the pupil expands and contracts in accordance with the amount of incident light. When a light source is emitted to acquire a fundus photographic image, the pupil diameter changes as shown in Figure 7(a), for example. Specifically, pupillary constriction begins some time after the light stimulus, such as the emission of the light source (T=0), and the pupil diameter becomes minimal. After that, the pupil diameter slowly recovers (dilates) and returns to the pupil diameter before the start of pupillary constriction. This is also true for the left eye when the right eye is photographed, for example. The time required for the pupil diameter to recover varies from person to person. Here, if the threshold used for judgment in step S603 is set to the threshold of the pupil diameter of the first eye before photographing the first eye, then photography will be delayed until the pupil diameter of the second eye has dilated to above the threshold. As a result, the examination time may be prolonged.

[0053] Some ophthalmic examination devices have a specified minimum pupil diameter for imaging (hereinafter referred to as the minimum pupil diameter). However, when the pupil diameter is close to the minimum pupil diameter, a phenomenon called flare (where the peripheral part of the fundus image becomes excessively bright) is more likely to occur. Therefore, it is necessary to perform a highly accurate alignment before fundus imaging in step S307. For this reason, the ophthalmic device may determine that imaging is possible if the pupil diameter of the second eye is dilated to or greater than the minimum pupil diameter. However, it is desirable for the ophthalmic device to determine that imaging is possible with the pupil as dilated as possible within the waiting time acceptable to the examiner or subject, and proceed to step S306. Accordingly, in this embodiment, when imaging the second eye, the threshold for determining whether imaging is possible is changed based on the measurement result of the elapsed time measurement means 2098, as shown by the thick line in Figure 7(b). Specifically, the time of imaging the first eye is set to T=0, and the time until T=Δt1 is determined using the pupil diameter Th1 before imaging the first eye as the threshold. For times after T = Δt1 + Δt2, the minimum pupil diameter Th2 is used as the threshold for determination. For the period Δt1 ≤ T ≤ Δt1 + Δt2, the threshold is changed linearly from Th1 to Th2. That is, the threshold for the period Δt1 ≤ T ≤ Δt1 + Δt2 is obtained using the pupil diameter Th1 before the first eye image was taken and the elapsed time since the first eye image was taken. This makes it possible to determine whether the second eye image can be taken when the pupil diameter has not reached the pupil diameter before the first eye image was taken, but has become a certain amount larger than the minimum pupil diameter. Furthermore, if the pupil does not recover from miosis even after a certain amount of time (Δt1 + Δt2 in this embodiment) has elapsed since the first eye image was taken, the ophthalmic examination device can wait with the minimum pupil diameter for which it can take an image as the threshold. Here, Th1 can be the pupil diameter immediately before the image was taken, which is stored in the memory unit 211 in step S307. Furthermore, taking into account calculation errors, Th1 may be set to a value that is a certain percentage smaller than the pupil diameter immediately before imaging, which is stored in the memory unit 211 in step S307. Also, even while waiting for recovery from miosis, the system may be configured to receive an imaging trigger at any time from the examiner and proceed to step S306.

[0054] In this embodiment, the threshold was changed linearly from Th1 to Th2 during the period Δt1≦T≦Δt1+Δt2, but this is not limited to this. For example, the threshold may be changed according to a quadratic function, changed in a stepwise manner, or a combination of multiple changing methods may be used. For example, in addition to the normal fundus photography mode, ophthalmic examination devices may have a small pupil photography mode for taking images when the pupil of the eye being examined is small, by changing the incident angle of illumination light, etc. The threshold may be changed as shown in Figure 7(c), using the minimum pupil diameter Th3 that can be photographed in the small pupil photography mode as the new threshold. In this case, the ophthalmic device can switch to the small pupil photography mode at T=Δt1+Δt2.

[0055] Once the system switches to small pupil imaging mode, it may proceed immediately to step S306, or a waiting period may be introduced again. Note that at least some of the thresholds for Th1, Th2, and Th3 may be the same. For example, when imaging the first eye, the average pupil diameter in a healthy eye (e.g., 4.0 mm) may be used as Th1, and the minimum pupil diameter (e.g., 3.0 mm) may be used as Th2 and Th3. These values ​​may also be changed depending on the number of images taken. Note that the times for Δt1, Δt2, Δt1+Δt2, etc., may use default values, or they may be configured to be set separately by the examiner. This makes it possible for each examiner to determine that imaging is possible with the pupil as dilated as possible within an acceptable waiting time.

[0056] The system will wait to take a picture until the pupil diameter of the second eye exceeds a threshold. During this time, the audio output unit 290 may output a message, for example, "Please blink." The system may also be configured to encourage pupil dilation by reducing the light intensity of the observation light source 250 and the internal fixation light 237. In this embodiment, the pupil diameter is calculated after alignment is completed, but the system is not limited to this. For example, alignment and pupil diameter calculation may be performed in parallel. This shortens the time up to step S603, and the examination time can be reduced, especially if the subject recovers quickly from pupillary constriction. When taking a picture of the first eye, the system may be configured to change the threshold for determining whether to take a picture based on the measurement result of the elapsed time measurement means 2098, similar to the second eye. In this case, the observation start time of the first eye can be set to initial values ​​such as T=0 and Th1=5.0mm. Alternatively, the system may be configured to compare with a threshold that is uniquely determined regardless of the elapsed time.

[0057] In this embodiment, the system determines that imaging is permissible when the alignment state detection means 2100 detects that the positional relationship between the ophthalmic examination device 201 and the eye E under examination is suitable for examination, but it is not limited to this. For example, if blinking of the subject is detected based on the anterior eye observation image, the system may be configured to temporarily suspend imaging. Alternatively, the system may determine whether or not the subject has nystagmus based on the anterior eye observation image, and if nystagmus is detected, it may temporarily suspend imaging and prompt the examiner to take the image.

[0058] Alternatively, the threshold used for determination in step S603 may be set higher than the threshold used for the eye without nystagmus. In these cases, it may be difficult to calculate the pupil diameter from the anterior eye observation image. If the difficulty in calculating the pupil diameter persists for multiple times, the system may be configured to temporarily suspend imaging and prompt the examiner to take the image. Alternatively, the system may be configured to detect the subject's gaze direction based on the anterior eye observation image or fundus observation image, and to temporarily suspend imaging if the subject is looking in a direction different from the desired direction. In this embodiment, one of the conditions for determining whether imaging is possible by the imaging timing determination means 2097 is that the pupil diameter calculated based on the anterior eye observation image is greater than or equal to a threshold, but the system is not limited to this, and any configuration that acquires illumination light incidence information and makes a determination is acceptable. For example, the system may be configured to calculate the area of ​​the pupil region based on the anterior eye observation image, compare it with a threshold, and determine that imaging is possible if it is greater than or equal to the threshold.

[0059] Alternatively, the system may extract the iris region and compare the ratio or difference in diameter or radius, or the ratio or difference in area, between the iris region and the pupil region with a threshold. For example, the system may compare the difference in diameter between the iris region and the pupil region with a threshold and determine that imaging is possible if the difference is less than the threshold.

[0060] Alternatively, the system may extract a specific region from the anterior frontal image and similarly determine the ratio or difference in diameter and area between the specific region and the pupil region. For example, a specific region may be set as a circle of a predetermined radius in the center of the anterior observation image, and the system may determine that imaging is possible if the ratio of the radius of the pupil region to the specific region is greater than or equal to a threshold. Alternatively, the system may acquire information regarding the incidence of fundus illumination light onto the eye under examination based on the fundus observation image. For example, in fundus observation images of an eye under examination in a constricted pupil state, a phenomenon called vignetting may occur where the peripheral area becomes dark. The system may also determine whether or not vignetting occurs in the fundus observation image.

[0061] Alternatively, the system may calculate the ratio of the brightness of the peripheral area to the brightness of the central part of the image, compare it with a threshold, and determine that imaging is possible if the ratio is above the threshold. In this case, the edge of the fundus observation image may be considered the peripheral area, or an area at a certain distance from the center of the fundus observation image may be considered the peripheral area. Alternatively, the system may acquire information regarding the incidence of fundus illumination light onto the eye under examination based on the distribution of photometric values ​​acquired by the photometric unit 2362. The photometric unit 2362 in this embodiment sequentially calculates photometric values ​​for a plurality of rectangular photometric areas provided on the image sensor 2360. Here, the number of photometric areas is less than or equal to the number of elements in the image sensor 2360. This makes it possible to acquire the distribution of photometric values ​​on the image sensor 2360 separately from the fundus observation image.

[0062] In this embodiment, the ophthalmic device determines the presence or absence of vignetting from the distribution information of photometric values ​​during fundus observation image acquisition. Specifically, the ratio of the photometric value calculated in the photometric area around the edge of the image sensor 2360 to the photometric value calculated in the central photometric area of ​​the image sensor 2360 is compared with a threshold, and if it is greater than or equal to the threshold, it is determined that imaging is possible.

[0063] Alternatively, the image sensor 224 of the anterior segment observation system may be provided with a photometric unit similar to that of the image sensor 2360. The photometric unit obtains information corresponding to the pupil diameter, which is acquired by binarizing the photometric values ​​of each photometric region during anterior segment observation image acquisition, as information regarding the incidence of fundus illumination light onto the eye under examination. The photometric value of the region corresponding to the pupil diameter will be lower than the photometric value of the regions other than the pupil diameter. By binarizing the photometric values ​​of each photometric region, it becomes possible to distinguish between the region corresponding to the pupil diameter and the regions other than the pupil diameter.

[0064] Alternatively, the system may calculate the pupil diameter from a tomographic image of the anterior segment of the eye captured by an OCT optical system and compare it with a threshold for determination. Furthermore, the system may calculate the ratio of the pupil area to the scanning range when acquiring a tomographic image of the anterior segment of the eye and compare it with a threshold for determination.

[0065] In this embodiment, data acquisition using fundus photography mode has been described as being performed consecutively for both the left and right eyes, but this is not limited to this. For example, a fundus photography mode may be used to synthesize fundus photography images of multiple fundus regions that differ in at least part to obtain a wide-area fundus photography image (hereinafter referred to as a panoramic composite image). Alternatively, multiple fundus photography modes may be used for only one eye, for example, to re-photograph the same eye due to reasons such as flare occurring in the first fundus photography image. Furthermore, the examiner may select the necessary photography mode as appropriate while acquiring data.

[0066] The above method reduces the patient's waiting time, even when multiple images of the eye under examination are taken using visible light. As a result, the examination time can be shortened.

[0067] [Differentiation] The ophthalmic examination system of this embodiment uses a machine learning model to configure the imaging timing determination means 2097. The machine learning model takes the anterior segment image of the first eye before imaging and the anterior segment image of the second eye before imaging as input, and outputs the time it takes for the pupil diameter of the second eye to recover from the constriction caused by imaging of the first eye to the same as the pupil diameter before imaging of the first eye.

[0068] The machine learning model is trained using pre-imaging images of the anterior segment of the first eye, pre-imaging images of the anterior segment of the second eye, and the time taken for recovery as training data. The machine learning model is a deep learning model trained using a convolutional neural network.

[0069] As in Embodiment 1, suppose the examiner selects a protocol for performing fundus photography on both eyes in the order of right eye then left eye. When photographing the right eye, in step S305, for example, a threshold set to Th1 = 4.0 mm, Th2 and Th3 = 2.0 mm, and T = Δt1 + Δt2 = 5.0 seconds is compared with the pupil diameter sequentially calculated from the anterior eye observation image of the right eye. At this time, one or more anterior eye observation images are saved.

[0070] The ophthalmic device performs imaging in step S307. In step S309, the stage 105 of the ophthalmic examination device 201 is moved to a position suitable for left eye imaging.

[0071] In step S305, the ophthalmic device acquires an anterior eye image of the left eye. The saved anterior eye image of the right eye and the anterior eye image of the left eye are input into a deep learning model to estimate the recovery time until the pupil diameter of the left eye becomes equal to that of the right eye. If the estimated recovery time is sufficiently longer than a predetermined time (T=Δt1+Δt2), the system may immediately switch to small pupil imaging mode. Alternatively, the estimated recovery time may be displayed on the display unit 210. This makes it possible to quickly start imaging even when it is anticipated that recovery from pupillary constriction will take longer than the time acceptable to the examiner or the patient.

[0072] Furthermore, if the estimated recovery time is sufficiently longer than T = Δt1 + Δt2, the system may be configured to ask the examiner whether or not to switch to the small pupil imaging mode. The examiner can determine whether or not to switch to the small pupil imaging mode based on the estimated recovery time displayed on the display unit 210. The imaging mode before switching to the small pupil imaging mode is an example of the first imaging mode. The small pupil imaging mode is an example of the second imaging mode.

[0073] In this embodiment, a deep learning model was used to estimate the time it takes for the pupil diameter to recover to the same level as before the first eye scan, but the embodiment is not limited to this. For example, when changing the threshold as shown in Figure 7(c), a deep learning model may be used to estimate the time it takes for the pupil diameter to exceed the threshold (threshold exceedance time). In this case as well, by displaying the estimated threshold exceedance time on the display unit 210, the examiner can perform the examination while checking the progress of the examination (threshold exceedance time).

[0074] Alternatively, a deep learning model may be used. The deep learning model is inputted with the following data: the pre-image anterior eye observation of the right eye, the post-image anterior eye observation when the pupil diameter of the right eye is at its minimum, the pre-image anterior eye observation of the left eye, the elapsed time from the start of the right eye imaging until the pupil diameter of the right eye is at its minimum, and the elapsed time from the start of the right eye imaging until the pre-image anterior eye observation of the left eye is obtained. The deep learning model estimates whether the pupil diameter of the left eye exceeds a threshold within T = Δt1 + Δt2.

[0075] Based on the estimation results, the system may switch to the small pupil imaging mode, as described above. Note that while the above explanation described a regression model for estimating time, it is not limited to this. For example, a deep learning model may be used as a classification model, taking the anterior eye observation image of the right eye (first eye) and the anterior eye observation image of the left eye (second eye) as input, and determining whether a threshold is exceeded within a certain time. If the classification model determines that the threshold will not be exceeded even after waiting Δt1+Δt2, the dynamic threshold curve (a curve representing the threshold that changes according to time T, as shown in Figure 7) may be changed. Alternatively, the time of Δt1+Δt2 may be changed.

[0076] Furthermore, while the deep learning model described above uses an image as input, it is not limited to this. Numerical information acquired by the illumination light incidence information acquisition means 2099 (such as numerical values ​​related to pupil diameter calculated by another means, or photometric value distribution) may also be used as input. In that case, a deep learning model (a learning model using a deep neural network) is used. Note that although a deep learning model was used in this embodiment, it is not limited to this. For example, based on the time change in pupil diameter of the right eye from before to after imaging, and the time change in pupil diameter of the left eye, an approximation formula may be used to estimate the recovery time until the pupil diameter of the left eye becomes equal to that of the right eye. In addition to the recovery time, the system may also estimate the threshold overrun time until the pupil diameter exceeds a threshold. The approximation formula may be a linear or curved approximation. This allows imaging to be started more quickly compared to using a deep learning model, even when it is anticipated that recovery from pupillary constriction will take longer than the time acceptable to the examiner or the subject. As a result, the examination time can be shortened.

[0077] [Differentiation] After the first eye is photographed, the ophthalmic examination device 201 of this embodiment turns off the light source 248. Therefore, it is expected that the pupil diameter will recover after the first eye is photographed. The ophthalmic examination system of this embodiment changes the threshold based on the change in the pupil diameter of the second eye. Specifically, if it is observed that the pupil diameter of the second eye is changing in the direction of reduction, or if the change in the pupil diameter of the second eye is slower than the predicted change in pupil diameter, the system switches to small pupil photography mode. Alternatively, it notifies the examiner that the patient's pupil dilation is slow and pauses the process. The prediction of the change in pupil diameter may be done using known information, such as shown in Figure 7(a), or using a machine learning model. For example, the prediction may be made using a model that takes the anterior segment image before the first eye is photographed and the anterior segment image before the second eye is photographed as inputs, and outputs the pupil diameter at each elapsed time from the constriction associated with the first eye photographed to the same pupil diameter as before the first eye photographed. This allows imaging to be started quickly in response to changes in the subject's pupil diameter.

[0078] [Differentiation] When performing fundus photography of an eye under examination, in addition to focusing on the macula and posterior pole, there are also cases where the focus is on the optic nerve head and peripheral areas, for example, to obtain a panoramic composite image. For example, when performing fundus photography focusing on the optic nerve head, the position of the internal fixation light 237 is changed to guide the subject's gaze outward compared to when focusing on the macula. At this time, the position of the subject's pupil also moves outward. Therefore, in order to prevent flare from occurring in the fundus images, alignment must be performed with high precision.

[0079] Therefore, if the threshold used to determine whether imaging is possible in step S603 is the same as when imaging is performed mainly on the macula, flare may be more likely to occur in the acquired fundus images. The ophthalmic examination system of this embodiment changes the method of changing the threshold according to the imaging site in the protocol selected by the examiner.

[0080] Let's explain this with reference to Figure 8. For example, suppose the examiner has selected a protocol for taking fundus photographs of the left and right eyes in the following order: right eye macula, right eye periphery, left eye macula, and left eye periphery. In this case, when photographing the right eye macula, in step S305, the pupil diameter calculated from the anterior eye observation image of the right eye is compared with a threshold that changes as shown in (i) of Figure (a) using the method described above to determine whether or not photography is permitted. If photography is permitted, the photograph is taken in step S307.

[0081] Next, when photographing the peripheral area of ​​the right eye, the stage 105 is not moved in step S309, but the position of the internal fixation light 237 is changed. In step S305, the pupil diameter calculated from the anterior eye observation image of the right eye is compared with a threshold that changes as shown in (ii) of Figure (a) using the method described above to determine whether or not photography is possible. If photography is possible, photography is performed in step S307. At this time, as described above, flare is more likely to occur when photographing the peripheral area, so Th2' ≥ Th2 is set. This makes the pupil diameter condition for which photography is deemed possible in step S603 stricter, allowing photography to be performed when recovery from miosis has progressed.

[0082] Next, when photographing the macula of the left eye, in step S309, the stage 105 is moved to the position for photographing the fundus of the left eye, and the position of the internal fixation light 237 is changed. In step S305, the pupil diameter calculated from the anterior eye observation image of the left eye is compared with the threshold that changes as shown in (i) of Figure (a) using the method described above to determine whether or not photography is possible. If photography is possible, photography is performed in step S307. The same process is repeated thereafter.

[0083] The threshold used in step S603 only needs to be set under stricter conditions when imaging the peripheral region than when imaging the macula. For example, when imaging the peripheral region, the time Δt2 may be extended. Alternatively, when imaging the peripheral region, the threshold may be changed by an upward-convex curve, as shown in (ii) of Figure (b). In this embodiment, the threshold change method has been described as two types, (i) and (ii), but is not limited to these. There may be more than two threshold change methods, which can be applied appropriately depending on the imaging site. For example, there may be three threshold change methods: for the macula, the optic nerve head, and other areas. This allows for the determination of the imaging timing according to the imaging site while reducing waiting time, even when imaging the eye under examination multiple times with visible light. As a result, the examination time can be shortened.

[0084] [Differentiation] The ophthalmic examination system of this embodiment can include a protocol that defines an imaging mode using an OCT optical system, which is defined by the imaging method, such as the scan pattern, and the imaging position. Furthermore, the ophthalmic examination system can determine the timing of imaging based on whether or not the subject has been administered a pupil-dilating agent.

[0085] Examples of imaging modes include a macular imaging mode for primarily imaging the macula with a cross scan, a wide-angle imaging mode for simultaneously imaging the optic nerve head and macula with a raster scan, and an anterior eye OCT imaging mode for imaging the anterior segment with a radial scan. In this embodiment, a protocol is selected in which data acquisition using the wide-angle imaging mode and the fundus imaging mode is performed sequentially for the left and right eyes, in the order of right eye then left eye.

[0086] At this time, as shown in Figure 9, the determination of whether imaging is permissible is made while changing the threshold. The flowchart shown in Figure 9 is explained as being performed in step S305 of Figure 3. Specifically, in step S901, it is determined whether or not the subject has been administered a pupil-dilating agent.

[0087] Whether or not a pupil-dilating agent has been administered can be included in the shooting mode settings, or it can be configured so that the examiner inputs or selects it as needed. If a pupil-dilating agent has been administered, the eye being examined is expected to be dilated regardless of whether or not shooting is performed, so as mentioned above, the ophthalmic examination system does not need to determine whether or not shooting is possible while checking the pupil diameter.

[0088] If a pupil-dilating agent has not been administered, proceed to step S902. In step S902, determine whether or not fundus photography is being performed. In the case of fundus photography, as mentioned above, pupillary constriction is likely to occur because the eye is photographed using visible light, whereas in the case of OCT photography, pupillary constriction is less likely to occur because the eye is photographed using invisible light. Therefore, if the shooting mode is related to OCT photography, it is not necessary to determine whether or not shooting is possible while checking the pupil diameter, as mentioned above.

[0089] In this embodiment of the ophthalmic examination system, if wide-angle imaging of the right eye is performed, it is determined in step S902 that it is not fundus imaging and proceeds to step S306. Next, if fundus imaging of the right eye is performed, it is determined in step S902 that it is fundus imaging, and the system determines whether imaging is possible by comparing the pupil diameter with a threshold using the same method as described with reference to Figure 6, etc., and proceeds to step S306 if imaging is possible.

[0090] Next, in the case of wide-angle imaging of the left eye, control is performed without checking the pupil diameter, similar to the case of wide-angle imaging of the right eye. Then, in the case of fundus imaging of the left eye, the pupil diameter is compared with a threshold using the same method as described above to determine whether imaging is possible or not. In this embodiment, the determination of whether or not to administer a pupil-dilating agent and whether or not to perform fundus imaging is made in step S305, but the system is not limited to this as long as the determination is made before step S603. This makes it possible to determine the timing of imaging according to the imaging mode while reducing waiting time, even when imaging the subject eye with visible light multiple times.

[0091] <Embodiment 2> Embodiment 1 described a configuration in which the subject's left and right eyes are photographed once each. This embodiment describes a configuration in which at least one eye of the subject is photographed two or more times. In this embodiment, as in Embodiment 1, it will be explained that the examiner selects a protocol for performing fundus photography of the left and right eyes in the order of right eye then left eye.

[0092] For example, in step S310 of Embodiment 1, the examiner checks the shooting results on screen 500 and operates the operation unit 501 to select to reshoot only the left eye using the same shooting mode. At this time, the ophthalmic examination system will photograph the subject's eyes in the order of right eye, left eye, left eye. When the right eye and the first left eye are photographed, the threshold used for judgment in step S603 is determined in the same way as in Embodiment 1. When the left eye is photographed for the second time, the threshold used for judgment in step S603 may be the same threshold as when the left eye was photographed for the first time.

[0093] Specifically, the ophthalmic examination system, for example, as shown in Figure 10(i), sets the time of the first left eye image capture as T=0, and makes a determination using the pupil diameter Th1 before the right eye image capture as the threshold for the time up to T=Δt1. For the time from T=Δt1+Δt2 onward, the determination is made using the minimum pupil diameter Th2 as the threshold. For the period Δt1≦T≦Δt1+Δt2, the determination is made using a threshold that has been linearly changed from Th1 to Th2. Alternatively, as shown in Figure 10(ii), the ophthalmic examination system may set the pupil diameter immediately before the first left eye image capture as Th1', and make a determination in step S603 by comparing the pupil diameter with a threshold that changes linearly from Th1' to Th2.

[0094] The pupil diameter Th1' immediately before the first left eye imaging is in the process of recovering from miosis caused by the right eye imaging, while it is the pupil diameter that was determined to be acceptable for imaging in step S603, and is also the pupil diameter that is presumed to be attainable for the second left eye imaging. Therefore, by using this value as the threshold, the waiting time for the second left eye imaging can be reduced. In this embodiment, Th1≧Th1' has been described, but it is not limited to this. The threshold may be changed so that the criteria for determining whether imaging is acceptable for the second left eye imaging is stricter than the criteria for determining whether imaging is acceptable for the first left eye imaging. This takes into account that during the first left eye imaging, as shown in Figure 8(b)(i), the examiner checked the imaging result on screen 500 and selected to re-import the image after determining that imaging was acceptable by comparing it with the threshold.

[0095] This reduces the likelihood that the examiner will determine that a re-shoot is necessary for the second shot of the left eye. Using the above method, even when photographing the same part of the same eye, the threshold for determining whether a shot is acceptable in step S603 can be changed. Furthermore, even when photographing the eye under examination multiple times using visible light, the timing of the shot can be determined according to the shooting mode while minimizing waiting time. As a result, the examination time can be shortened.

[0096] [Differentiation] The ophthalmic examination system of this embodiment manages multiple examination information of a subject and has a follow-up function to check for changes over time. For example, in the case of a subject suspected of having glaucoma, examinations may be performed periodically. In this case, for example, the threshold for the current examination can be determined based on the pupil diameter stored in the memory unit 211 during the fundus photography of the previous examination.

[0097] For example, suppose that during the previous fundus photography, the pupil diameter of the right eye was 4.5 mm and the pupil diameter of the left eye was 4.2 mm. In this case, for the current examination, when photographing the fundus of the right eye, the ophthalmic device sets Th1 to 4.5 mm (the pupil diameter from the previous fundus photography of the right eye) and Th2 to 3.0 mm. Then, similar to Embodiment 1, it determines whether or not photography is possible using a threshold that has been changed according to the elapsed time. When photographing the fundus of the left eye, Th1 is set to 4.2 mm (the pupil diameter from the previous fundus photography of the left eye) and Th2 to 3.0 mm. Then, similar to Embodiment 1, it compares the threshold and the pupil diameter using a threshold that has been changed according to the elapsed time and determines whether or not photography is possible.

[0098] In this way, by using the pupil diameter from the previous fundus photography as the threshold for the current examination, the likelihood of the examiner determining that re-photography is necessary can be reduced. As a result, the examination time can be shortened. Alternatively, the system may be configured to wait until the pupil diameter reaches 4.5 mm when photographing the right eye's fundus, and until it reaches 4.2 mm when photographing the left eye's fundus. Alternatively, if multiple examinations have been performed previously, the threshold for the current examination may be determined based on statistical values ​​such as the minimum, average, and median pupil diameters from previous fundus photography examinations.

[0099] In this embodiment, the threshold values ​​for each of the subject's left and right eyes were set to be the same regardless of the timing of the examination, but this is not limited to this. It is generally known that pupil diameter decreases with age. It is also known that the muscle strength of the muscles that adjust pupil size is affected by aging, so the rate of change in pupil diameter in response to the amount of light emitted by the illumination light decreases. For this reason, even when photographing the same eye of the same subject, the threshold used for judgment in step S603 may be determined by taking age into account. For example, the threshold for the current examination may be determined by multiplying the pupil diameter at the time of fundus photography in the previous examination by a certain percentage. Alternatively, the threshold for the current examination may be determined using the pupil diameter calculated by a regression line based on the pupil diameter at the time of fundus photography in multiple previous examinations. Similarly, the threshold may be determined by estimating the change in pupil diameter at the time of the current examination based on the change in pupil diameter at the time of fundus photography in the previous examination or multiple previous examinations. This makes it possible to adaptively calculate variables such as Δt1, Δt2, and Δt1+Δt2 in Figure 10 for each subject.

[0100] These methods allow for the use of pupil diameter data from previous examinations, enabling the application of appropriate thresholds for each individual subject. Even when multiple images of the subject's eye are taken using visible light, the timing of the images can be determined according to the imaging mode. As a result, examination time can be shortened.

[0101] <Embodiment 3> Embodiments 1 and 2 described a configuration in which the pupil diameter of the adjoining eye (the eye opposite to the eye being photographed) is used as the threshold for the pupil diameter of the eye being photographed. This embodiment describes a configuration for photographing the fundus of a subject whose left and right pupil diameters are different under normal conditions.

[0102] In cases of pupillary inequality, the left and right pupil diameters differ by approximately 0.5 to 1 mm or more under normal conditions. Therefore, especially when the normal pupil diameter of the second eye is smaller than that of the first eye, using the pupil diameter of the other eye before imaging as a threshold using the method described above may result in a long delay before imaging can begin. In this embodiment, the pupil diameter of the first eye after imaging is estimated using a regression equation based on the relationship between the amount of light emitted from the observation light source 250 and the pupil diameter during observation of the first eye, and the amount of light emitted from the imaging light source 248 during imaging. This estimation may also be performed using a machine learning model.

[0103] Next, the ophthalmic device compares the estimated pupil diameter with the pupil diameter of the second eye before imaging. If the pupil diameter of the second eye before imaging is approximately the same as the estimated pupil diameter, the pupil diameter of the other eye before imaging is used as the threshold for determining whether imaging is possible in step S603. On the other hand, if the pupil diameter of the second eye before imaging is smaller than the estimated pupil diameter by a certain percentage or more, the threshold for determining whether imaging is possible in step S603 is changed. Specifically, for example, if the pupil diameter of the second eye before imaging is 20% smaller than the estimated pupil diameter, the threshold determined from the pupil diameter of the other eye before imaging is lowered by 20% within a range greater than the minimum pupil diameter. This 20% lower value is used as the threshold for determining whether imaging is possible in step S603. Alternatively, imaging is temporarily paused and the examiner is prompted to take the image.

[0104] Using the method described above, even if the pupil diameters of the left and right eyes differ under normal conditions, the timing of the shot can be determined according to the shooting mode while minimizing the waiting time. As a result, the examination time can be shortened.

[0105] (Other embodiments) Furthermore, the disclosed technology can also be realized by performing the following process: that is, the disclosed technology can also be realized by supplying software (programs) that implement one or more functions of the various embodiments described above to a system or device via a network or storage medium, and the computer (or CPU, MPU, etc.) of that system or device reads and executes the program. The computer may have one or more processors or circuits and may include a network of separate computers or separate processors or circuits in order to read and execute computer executable instructions. In this case, the processor or circuit may include a central processing unit (CPU), a microprocessing unit (MPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), or a field-programmable gateway (FPGA). The processor or circuit may also include a digital signal processor (DSP), a dataflow processor (DFP), or a neural processing unit (NPU).

[0106] (Composition 1) An ophthalmic examination device that photographs the fundus of an eye under examination based on information regarding the pupil diameter of the eye under examination, When performing a first photograph and a second photograph that is performed immediately after the first photograph, In the first imaging, imaging is performed when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than the first value. In the second imaging procedure, the ophthalmic examination device performs imaging when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a second value which is less than the first value.

[0107] (Configuration 2) The ophthalmic examination device according to configuration 1, wherein the information relating to the pupil diameter of the eye to be examined is the pupil diameter of the eye to be examined obtained using an observation image of the anterior segment of the eye to be examined.

[0108] (Composition 3) The ophthalmic examination apparatus according to configuration 1 or 2, wherein the second value is obtained using an observational image of the anterior segment of the eye to be examined before performing the first imaging.

[0109] (Composition 4) The ophthalmic examination apparatus according to any one of configurations 1 to 3, wherein the second value is obtained using the pupil diameter of the eye to be examined, obtained using an observation image of the anterior segment of the eye to be examined taken before the first imaging is performed, and the elapsed time since the first imaging was performed.

[0110] (Composition 5) An ophthalmic examination device according to any one of configurations 1 to 4, wherein the first imaging is imaging of the fundus of either the left or right eye of the eye being examined, and the second imaging is imaging of the fundus of the other eye of either the left or right eye of the eye being examined.

[0111] (Composition 6) The ophthalmic examination device according to any one of configurations 1 to 5, characterized in that the information relating to the pupil diameter of the eye under examination is one of the following: pupil area, pupil shape, ratio of the pupil to the iris, width between the edge of the iris and the edge of the pupil, ratio of the pupil to a specific region, anterior eye photometric value distribution, and fundus photometric value distribution.

[0112] (Composition 7) Between the execution of the first shooting and the execution of the second shooting, By inputting information regarding the pupil diameter of the eye being examined before the first imaging and information regarding the pupil diameter of the eye being examined before the second imaging into a machine learning model, the time until the pupil diameter of the eye being examined is greater than the second value is estimated. If the estimated time is longer than a predetermined time, the system switches to a second shooting mode that is different from the first shooting mode used in the first shooting. An ophthalmic examination apparatus according to any one of configurations 1 to 6, which performs the second shooting using the second shooting mode.

[0113] (Composition 8) The ophthalmic examination apparatus according to configuration 7, wherein the second shooting mode is a small pupil shooting mode.

[0114] (Composition 9) The system further includes a fixation light that guides the gaze direction of the eye being examined, An ophthalmic examination apparatus according to any one of configurations 1 to 8, wherein, between the execution of the first imaging and the execution of the second imaging, if the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is smaller than the second value, the light intensity of the fixation lamp is reduced to that of the light intensity of the fixation lamp in the first imaging.

[0115] (Method 1) A control method for an ophthalmic examination device that photographs the fundus of an eye under examination based on information regarding the pupil diameter of the eye under examination, When performing a first photograph and a second photograph that is performed immediately after the first photograph, The first imaging procedure includes the step of performing imaging when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a first value, The second imaging procedure includes the step of performing imaging when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a second value which is less than the first value, A control method for an ophthalmic examination device having the following features.

[0116] (Program 1) A program that causes a computer to execute the control method for the ophthalmic examination device described in Method 1. [Explanation of Symbols]

[0117] 201 Ophthalmic Examination Equipment 209 Image Processing Equipment 210 Display section 211 Storage section 212 Operation section 290 Audio output section

Claims

1. An ophthalmic examination device that photographs the fundus of an eye under examination based on information regarding the pupil diameter of the eye under examination, When performing a first photograph and a second photograph that is performed immediately after the first photograph, In the first imaging, imaging is performed when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a first value. In the second imaging procedure, the ophthalmic examination device performs imaging when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a second value which is less than the first value.

2. The ophthalmic examination device according to claim 1, wherein the information relating to the pupil diameter of the eye to be examined is the pupil diameter of the eye to be examined obtained using an observation image of the anterior segment of the eye to be examined.

3. The ophthalmic examination apparatus according to claim 1, wherein the second value is obtained using an observational image of the anterior segment of the eye to be examined before performing the first imaging.

4. The ophthalmic examination apparatus according to claim 1, wherein the second value is obtained using the pupil diameter of the eye to be examined, obtained using an observation image of the anterior segment of the eye to be examined taken before the first imaging is performed, and the elapsed time since the first imaging was performed.

5. The ophthalmic examination apparatus according to claim 1, wherein the first imaging is imaging of the fundus of either the left or right eye of the eye being examined, and the second imaging is imaging of the fundus of the other eye of either the left or right eye of the eye being examined.

6. The ophthalmic examination device according to claim 1, characterized in that the information relating to the pupil diameter of the eye under examination is one of the following: pupil area, pupil shape, ratio of pupil to iris, width between the iris margin and the pupil margin, ratio of pupil to a specific region, anterior eye photometric value distribution, and fundus photometric value distribution.

7. Between the execution of the first photograph and the execution of the second photograph, By inputting information regarding the pupil diameter of the eye under examination before the first imaging and information regarding the pupil diameter of the eye under examination before the second imaging into a machine learning model, the time until the pupil diameter of the eye under examination is greater than the second value is estimated. If the estimated time is longer than a predetermined time, the system switches to a second shooting mode that is different from the first shooting mode used in the first shooting. The ophthalmic examination apparatus according to claim 1, wherein the second shooting mode is used to perform the second shooting.

8. The ophthalmic examination apparatus according to claim 7, wherein the second shooting mode is a small pupil shooting mode.

9. The system further includes a fixation light that guides the gaze direction of the eye being examined, The ophthalmic examination apparatus according to claim 1, wherein, between the execution of the first imaging and the execution of the second imaging, if the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is smaller than the second value, the light intensity of the fixation lamp is reduced to that of the light intensity of the fixation lamp in the first imaging.

10. A control method for an ophthalmic examination device that photographs the fundus of an eye under examination based on information regarding the pupil diameter of the eye under examination, When performing a first photograph and a second photograph that is performed immediately after the first photograph, The first imaging procedure includes the step of performing imaging when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a first value, The second imaging procedure involves the step of performing imaging when the information regarding the pupil diameter of the eye under examination indicates that the pupil diameter of the eye under examination is greater than a second value which is less than the first value, A control method for an ophthalmic examination device having the following features.

11. A program that causes a computer to execute the control method of the ophthalmic examination apparatus described in claim 10.

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