JP2024007762A - Ophthalmologic device, control method thereof, and program - Google Patents

Abstract

To provide a mechanism to accurately align an ophthalmologic device for an eye to be examined.SOLUTION: An ophthalmologic device includes: image acquisition means 211 for acquiring an anterior eye part image obtained by imaging the anterior eye part including the pupil of an eye to be examined; pupil extraction means 212 for extracting the pupil from a first partial area and a second partial area in at least one anterior eye part image acquired by the image acquisition means 211; and pupil center calculation means 213 for calculating a first pupil center in the pupil extracted from the first partial area on the basis of the pupil extracted from the second partial area.SELECTED DRAWING: Figure 1

Description

The present invention relates to an ophthalmologic apparatus, a control method thereof, and a program.

For example, a fundus camera device is widely used as an ophthalmological device for photographing the fundus of an eye to be examined. A fundus camera device is a useful device in ophthalmological diagnosis because it can obtain an image of the fundus of an eye to be examined. In addition to fundus camera devices, various ophthalmological devices are used, such as optical coherence tomography (OCT), ocular refractometers, and tonometers. In such an ophthalmological apparatus, it is important to accurately align the photographing section (mainly the measurement optical system) of the ophthalmological apparatus to the eye to be examined in order to photograph the eye to be examined.

Patent Document 1 describes a technique for automatically aligning the ophthalmological apparatus with respect to the eye to be examined by detecting the positional relationship between the eye to be examined and the imaging unit of the ophthalmological apparatus using an image of the pupil observed through a split prism. There is.

Japanese Patent Application Publication No. 2013-150696

However, since there are individual differences in the eyes to be examined, pupil detection accuracy decreases due to various factors such as pupil diameter, pupil shape, lowering of the eyelids, and scattering distribution of illumination light, and as a result, alignment accuracy decreases. There is a problem that it decreases. In particular, in a fundus camera device, when alignment accuracy decreases, artifacts (flare) occur in which light reflected by the cornea or crystalline lens of the eye to be examined is reflected in a photographed image (fundus image). Therefore, it is very important to be able to accurately align the ophthalmological apparatus with respect to the eye to be examined.

The present invention has been made in view of these problems, and an object of the present invention is to provide a mechanism that can accurately align an ophthalmologic apparatus with respect to an eye to be examined.

The ophthalmologic apparatus of the present invention includes an acquisition unit that acquires an anterior segment image obtained by photographing an anterior segment including a pupil of an eye to be examined, and at least one of the anterior segment images acquired by the acquisition unit. extraction means for extracting the pupil from the first partial area and the second partial area; and center calculation means for calculating a first pupil center in the pupil.
Further, the present invention includes a method for controlling the above-mentioned ophthalmological apparatus, and a program for causing a computer to function as each means of the above-mentioned ophthalmological apparatus.

According to the present invention, it is possible to accurately align an ophthalmologic apparatus with respect to an eye to be examined.

1 is a diagram illustrating an example of a schematic configuration of an ophthalmologic apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of the internal configuration of the optical head section shown in FIG. 1. FIG. FIG. 2 is a diagram showing a display example of the display section shown in FIG. 1; 3 is a flowchart illustrating an example of a processing procedure in a method for controlling an ophthalmologic apparatus according to an embodiment of the present invention. FIG. 2 is a diagram for explaining an anterior segment observation image in an embodiment of the present invention. 5 is a flowchart illustrating an example of a processing procedure for calculating a pupil position deviation amount included in the anterior segment alignment processing in step S401 of FIG. 4. FIG. 7 is a diagram for explaining approximation to an ellipse model in step S604 of FIG. 6. FIG.

Hereinafter, modes for carrying out the present invention (embodiments) will be described with reference to the drawings. However, the shapes of the components and the relative positions of the components described below are not limited to the embodiments of the present invention and are arbitrary, and may vary depending on the configuration of the ophthalmological device to which the present invention is applied or various It can be changed depending on the conditions. Furthermore, in the drawings, the same reference numerals are used for components that are the same or functionally similar.

<Schematic configuration of ophthalmological equipment>
FIG. 1 is a diagram showing an example of a schematic configuration of an ophthalmologic apparatus 1 according to an embodiment of the present invention. As the ophthalmologic apparatus 1 shown in FIG. 1, for example, it is preferable to use a fundus camera apparatus that photographs the fundus of an eye to be examined, but the present invention also includes other ophthalmologic apparatuses other than the fundus camera apparatus.

As shown in FIG. 1, the ophthalmologic apparatus 1 includes an imaging section 10, a control section 20, an input section 30, and a display section 40. Further, as shown in FIG. 1, the photographing section 10 includes an optical head section 100, a stage section 150, a base section 160, and a face receiving section 170.

The optical head unit 100 irradiates the eye to be examined with light and detects the return light from the eye to take images of the fundus including an anterior segment observation image, a fundus observation image, and a fundus photographed image. The structure includes an optical system for

The stage section 150 is configured to be able to move the optical head section 100 in the X direction, Y direction, and Z direction in FIG. 1 by driving a motor (not shown) under the control of the control section 20, for example.

The base section 160 has a stage section 150, an optical head section 100, and a face receiving section 170 mounted thereon.

The face support section 170 is a chin rest that can encourage fixation of the subject's eyes (tested eyes) by fixing the subject's chin and forehead. The face receiving section 170 is configured to be movable in the Y direction in FIG. 1 by being driven by a driving member such as a motor (not shown) under the control of the control section 20, for example.

The control section 20 is electrically connected to the imaging section 10, the input section 30, and the display section 40, and is configured to be able to control these components. The control unit 20 can align the optical head unit 100 of the ophthalmological apparatus 1 with respect to the eye to be examined, for example, by controlling the movement of the stage unit 150. The control unit 20 also generates and acquires an anterior segment observation image, a fundus image including a fundus observation image and a fundus photographed image based on various image signals obtained by the imaging unit 10. You can also do it.

The control unit 20 can be configured using a general computer including a processor and memory, but may also be configured using a computer dedicated to the ophthalmologic apparatus 1. Note that the control unit 20 may be configured using not only a separate (external) computer to which the imaging unit 10 is communicably connected, but also a built-in (internal) computer in the imaging unit 10. Further, the control unit 20 may be configured using, for example, a personal computer, a desktop PC, a notebook PC, a tablet PC (portable information terminal), or the like.

As shown in FIG. 1, the control section 20 includes an alignment section 21, a focus adjustment section 22, a light amount adjustment section 23, a fundus photographing processing section 24, and a storage section 25. As described above, when the control unit 20 is configured using a computer, each configuration of the control unit 20 is controlled by the processor of the computer executing a program stored in the storage unit 25 corresponding to the memory of the computer. Parts 21 to 24 are realized. In addition to the above-mentioned programs, the storage unit 25 also stores various data (including images) necessary for the processing of the control unit 20, and also stores various data (including images) obtained through the processing of the control unit 20. (including images). Each component 21 to 24 of the control unit 20 will be described later using FIG. 4. Further, as shown in FIG. 1, the alignment section 21 includes an image acquisition means 211, a pupil extraction means 212, a pupil center calculation means 213, a relative position calculation means 214, and a movement means 215. Each means 211 to 215 of the alignment section 21 will be described later using FIG. 6.

The input unit 30 is a component that inputs instructions to the control unit 20. Specifically, the input unit 30 includes, for example, a keyboard and a mouse.

The display unit 40 is configured by, for example, an arbitrary monitor. The display section 40 displays various information such as patient information, various images, and a mouse cursor according to the operation of the input section 30 under the control of the control section 20 . Note that the display section 40 may be configured with a touch panel display, and in this case, the display section 40 also serves as the input section 30.

Note that in the ophthalmological apparatus 1 shown in FIG. 1, the imaging section 10, the control section 20, the input section 30, and the display section 40 are each configured separately, but some or all of these components may be configured as an integrated unit. You can leave it there. Further, other imaging devices, storage devices, etc. (not shown) may be electrically connected to the control unit 20.

<Internal configuration of optical head section>
FIG. 2 is a diagram showing an example of the internal configuration of the optical head section 100 shown in FIG. 1. FIG. 2 shows an XYZ coordinate system corresponding to the XYZ coordinate system shown in FIG.

The optical head unit 100 is provided with an optical system for photographing the anterior segment Ea of the eye E to be examined and the fundus Ef of the eye E to be examined. Hereinafter, various optical systems arranged inside the optical head section 100 will be explained using FIG. 2.

In the optical head section 100, an objective lens 111 is arranged facing the eye E to be examined. A first dichroic mirror 112 functioning as an optical path branching section is arranged on the optical axis L1 of the objective lens 111. The first dichroic mirror 112 branches the light into the optical path (optical axis L2) of the anterior ocular segment measurement optical system 120 and the optical path (optical axis L3) of the fundus photographing optical system 130 for each wavelength band.

On the optical axis L2 in the reflection direction of the first dichroic mirror 112, there are a lens 121, a prism 122, an aperture 123, and a lens 124 as an anterior eye measurement optical system 120 for observing the anterior eye Ea of the eye E. , and an image sensor 125 are arranged. Further, near the objective lens 111, an anterior eye segment observation light source 126 that illuminates the anterior eye segment Ea of the eye E to be examined is arranged as the anterior eye segment measurement optical system 120. The image sensor 125 is a monochrome sensor with sensitivity in the infrared region. The image sensor 125 is electrically connected to the control section 20 and transmits an image signal to the control section 20 according to the detected light. The control unit 20 can generate and acquire an anterior segment observation image based on the image signal received from the image sensor 125, and display the anterior segment observation image on the display unit 40.

A fundus photographing optical system 130 for photographing the fundus Ef of the eye E to be examined is arranged on the optical axis L3 in the transmission direction of the first dichroic mirror 112. Specifically, as the fundus photographing optical system 130, a perforated mirror 131, a photographic aperture 132, a focus lens 133, an imaging lens 134, a second dichroic mirror 135, and an image sensor 136 are arranged. The perforated mirror 131 has an opening in the center. The focus lens 133 is held movably in the direction of the optical axis L3 indicated by the arrow in FIG. 2 by a drive unit such as a motor (not shown) controlled by the control unit 20. By moving the focus lens 133 on the optical axis L3, the focus of the fundus photographing optical system 130 can be adjusted. The optical path on the optical axis L3 is branched by the second dichroic mirror 135 into an optical path leading to the image sensor 136 and an optical path leading to the fixation lamp 137 for each wavelength band. The image sensor 136 is a sensor that is sensitive to visible light and infrared light, and is a fundus image sensor that serves both for video observation and still image photography. The image sensor 136 is electrically connected to the control section 20 and transmits an image signal to the control section 20 according to the detected light. The control unit 20 can generate and acquire a fundus image such as a fundus observation image or a fundus photographed image based on the image signal received from the image sensor 136, and display the fundus image on the display unit 40. The fixation lamp 137 is a light source that emits visible light to encourage the subject to fixate. Note that the fixation lamp 137 may also be provided with an aperture (not shown) for cutting off the light flux necessary for photographing the fundus.

On the optical axis L4 in the reflection direction of the perforated mirror 131, a fundus illumination optical system 140 for illuminating the fundus Ef of the eye E to be examined is arranged. Specifically, as the fundus illumination optical system 140, a corneal baffle 141, a relay lens 142, a focus optotype unit 143, a lens 144, a ring slit 145, a crystalline lens baffle 146, and a third dichroic mirror 147 are arranged. The corneal baffle 141 has a light blocking point at the center. The ring slit 145 has a ring-shaped slit opening. The crystalline lens baffle 146 has a function as a light shielding member having a light shielding point. The third dichroic mirror 147 has a characteristic of transmitting infrared light and reflecting visible light. Further, in the reflection direction of the third dichroic mirror 147, a condenser lens 148a and a white LED light source 148b are arranged. The white LED light source 148b is a photographing light source in which a plurality of white LEDs that emit visible pulsed light are arranged. A condenser lens 149a and an infrared LED light source 149b are arranged in the transmission direction of the third dichroic mirror 147. The infrared LED light source 149b is an observation light source in which a plurality of infrared LEDs that emit constant infrared light are arranged. Note that the drive of the white LED light source 148b and the infrared LED light source 149b is controlled by the control unit 20. The fundus Ef of the eye E to be examined can be illuminated by the light from the white LED light source 148b and/or the infrared LED light source 149b.

The focus optotype unit 143 is an optical member that provides an optotype for focusing using the focus lens 133, and in this embodiment, it irradiates a split bright line as an example of the optotype. The focus optotype unit 143 according to this embodiment includes a split optotype member that is movable along the optical axis L4 in conjunction with the focus lens 133. This split optotype member is 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 unit 20. Further, the split bright line emitted by the focus optotype unit 143 passes through the relay lens 142 and is reflected by the perforated mirror 131 toward the first dichroic mirror 112 side. The split bright line reflected by the perforated mirror 131 is then projected onto the fundus Ef of the eye E to be examined via the first dichroic mirror 112 and the objective lens 111. The control unit 20 can calculate the amount of focus shift by detecting the position of the split bright line from the fundus observation image.

Further, a fundus measurement optical system is constituted by the fundus photographing optical system 130 arranged on the optical axis L3 and the fundus illumination optical system 140 arranged on the optical axis L4.

<Example of display on display>
FIG. 3 is a diagram showing a display example of the display section 40 shown in FIG. 1. Specifically, the display unit 40 shown in FIG. 3 displays an example of an anterior segment observation image 310, a fundus observation image 320, and a fundus photographed image 330. The anterior segment observation image 310 is an image generated by the control unit 20 processing the output of the image sensor 125. The fundus observation image 320 is a monochrome image generated by the control unit 20 processing the output of the image sensor 136. The fundus photographed image 330 is a color image generated by the control unit 20 processing the output of the image sensor 136.

<Processing procedure in the ophthalmological device control method>
FIG. 4 is a flowchart illustrating an example of a processing procedure in a method for controlling the ophthalmologic apparatus 1 according to the embodiment of the present invention. Specifically, FIG. 4 is a flowchart illustrating an example of a processing procedure in a method for photographing the fundus Ef of the eye E to be examined.

First, in step S401, the alignment unit 21 of the control unit 20 uses the anterior segment observation image, which is the anterior segment image of the subject's eye E, to The optical head section 100 is aligned. Specifically, the alignment section 21 first uses the anterior segment observation image generated based on the image signal received from the image sensor 125 to align the optical head section 100 with the optical head section 100 through the process shown in the flowchart shown in FIG. 6, which will be described later. The amount of positional deviation in the XYZ directions with respect to the optometry E is calculated. More specifically, here, the alignment unit 21 calculates the amount of positional deviation of the pupil in the anterior segment Ea of the eye E to be examined. Next, the alignment section 21 drives the stage section 150 to move the optical head section 100 according to the calculated positional deviation amount. This process is repeated and the anterior segment alignment is completed when the calculated amount of positional deviation becomes less than a predetermined value.

Subsequently, in step S402, the focus adjustment section 22 of the control section 20 performs focus adjustment. Specifically, the focus adjustment unit 22 of the control unit 20 calculates the focus shift amount by detecting the position of the split bright line from the fundus observation image, and drives the focus lens 133 according to the calculated shift amount. , perform focus adjustment.

Subsequently, in step S403, the light amount adjustment section 23 of the control section 20 performs light amount adjustment. Since there are individual differences in the reflectance of the fundus Ef of the subject's eye E, the light amount adjustment section 23 of the control section 20 specifically adjusts the infrared LED light source 149b so that the brightness of the fundus observation image falls within a predetermined range. Adjust the light intensity.

Subsequently, in step S404, the fundus photographing processing section 24 of the control section 20 performs a process of photographing the fundus Ef of the eye E to be examined. Specifically, the fundus photographing processing section 24 of the control section 20 turns on the white LED light source 148b, and uses the image sensor 136 to acquire a fundus photographed image. The lighting time and light intensity of the white LED light source 148b at this time are determined based on the light intensity of the infrared LED light source 149b adjusted by the light intensity adjustment section 23 of the control section 20 in step S403.

When the process of step S404 ends, the process of the flowchart shown in FIG. 4 ends.

Note that the process of the flowchart shown in FIG. 4 described here is just an example. In this embodiment, the order of processing may be different, and the specific content of processing may be different. Further, there may be additional processing other than the processing shown in the flowchart shown in FIG. 4 described here. For example, in the process of the flowchart shown in FIG. 4, anterior segment alignment is executed only in step S401, but it may be executed in other steps. Specifically, for example, anterior segment alignment may be performed again immediately before the fundus photographing process in step S404. During the focus adjustment in step S402 and the light intensity adjustment in step S403, the alignment to the subject's eye E may deviate, so by performing anterior segment alignment again just before step S404, a more suitable Fundus photography images may be obtained. Further, even after the anterior segment alignment is completed in step S401, anterior segment tracking may be performed to continue aligning the eye E to be examined. In that case, it is desirable to perform the processing after step S402 and anterior segment tracking in parallel.

<Anterior segment observation image (anterior segment image)>
FIG. 5 is a diagram for explaining an anterior segment observation image in the embodiment of the present invention. In FIG. 5, components similar to those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed explanation thereof will be omitted. Further, FIGS. 5A, 5C, and 5E illustrate an XYZ coordinate system corresponding to the XYZ coordinate system shown in FIGS. 1 and 2.

FIG. 5A is a diagram of a state in which the optical head section 100 and the eye E to be examined are aligned, viewed from above (from the +Y direction) the ophthalmological apparatus 1. The pupil Ep of the anterior segment Ea of the eye E to be examined is observed through the objective lens 111. A viewing angle 501 and a viewing angle 502 shown in FIG. 5A indicate the apparent angles when the pupil Ep is observed from a virtual viewpoint due to the prism effect of the prism 122 shown in FIG. 2, respectively. The reflected and scattered light flux from the anterior segment Ea of the eye E to be examined forms an image on the prism 122 once, and then forms an image on the image sensor 125 again. FIG. 5(b) is a diagram showing an example of an anterior segment observation image 503 obtained from the output of the image sensor 125 in the state shown in FIG. 5(a). The anterior segment observation image 503 is divided by the prism 122 into an upper half partial region 504 and a lower half partial region 505. Pupils (black portion located in the center) in the upper half partial region 504 and the lower half partial region 505 indicate the pupil Ep observed at the viewing angle 501 and the viewing angle 502 in FIG. 5A, respectively. In this embodiment, as shown in FIG. 5A, the prism 122 shown in FIG. A sensor 125 is arranged.

FIG. 5C is a view from above of the ophthalmological apparatus 1 in a state where the optical head section 100 and the eye E to be examined are not aligned and the working distance is longer than the ideal distance. At this time, the viewing angle 511 shown in FIG. 5(c) moves to the right side of the viewing angle 501 shown in FIG. 5(a) (indicated by a dotted line in FIG. 5(c)), and the viewing angle 511 shown in FIG. The viewing angle 512 moves to the left of the viewing angle 502 shown in FIG. 5(a) (indicated by a dotted line in FIG. 5(c)). FIG. 5(d) is a diagram showing an example of an anterior segment observation image 513 obtained from the output of the image sensor 125 in the state shown in FIG. 5(c). The anterior segment observation image 513 is divided by the prism 122 into an upper half partial region 514 and a lower half partial region 515. Pupils (black portion located in the center) in the upper half partial region 514 and the lower half partial region 515 indicate the pupil Ep observed at the viewing angle 511 and the viewing angle 512 in FIG. 5(c), respectively. The pupil in the upper half partial region 514 moves to the right in accordance with the viewing angle 511 shown in FIG. Move to the left accordingly. Therefore, looking at the anterior segment observation image 513 shown in FIG. 5(d), it can be seen that the distance between the optical head section 100 and the eye E to be examined is long and the alignment is not correct. On the other hand, if the distance between the optical head section 100 and the eye E to be examined is too short, the image for anterior eye segment observation obtained from the output of the image sensor 125 is split in the opposite direction to that in FIG. 5(d). Therefore, it is possible to determine in which direction and to what degree the alignment between the optical head section 100 and the eye E to be examined is deviated from the anterior segment observation image obtained from the output of the image sensor 125.

FIG. 5E is a view from above of the ophthalmological apparatus 1 in a state where the line of sight of the eye E to be examined is tilted. In order to photograph the eye E so that the area other than the macular region appears in the center of the fundus photographed image, it is necessary to photograph the eye E with its line of sight tilted as shown in FIG. 5(e). For example, when performing imaging focusing on the optic disc of the eye E, the imaging may be performed in the state shown in FIG. 5(e). In this case, the examiner can prompt the eye E to move the line of sight by switching the lighting position of the fixation lamp 137 from the input unit 30. Further, as for the alignment state, FIG. 5(e) shows a state in which the optical head section 100 and the eye E to be examined are aligned similarly to FIG. 5(a). In the state of FIG. 5E, the eye E to be examined is tilted, so the width of the visual angle 521 is smaller than the width of the visual angle 522. FIG. 5(f) is a diagram showing an example of an anterior segment observation image 523 obtained from the output of the image sensor 125 in the state shown in FIG. 5(e). The anterior segment observation image 523 is divided by the prism 122 into an upper half partial region 524 and a lower half partial region 525. In the anterior segment observation image 523 shown in FIG. 5(f), the width of the viewing angle 521 and the width of the viewing angle 522 are different as shown in FIG. 5(e), so the upper half partial region 524 and the lower half partial region 525, resulting in an image in which the width of the pupil is different. Specifically, the pupil in the upper half partial region 524 has a narrow width corresponding to the viewing angle 521 shown in FIG. 5(e), and the pupil in the lower half partial region 525 has a narrow width as shown in FIG. 5(e). The width is wide corresponding to the viewing angle 522.

Therefore, even when the optical head unit 100 and the eye E to be examined are aligned, the image always shows the upper and lower pupils aligned, as in the anterior segment observation image 503 shown in FIG. 5(b). isn't it. Depending on the inclination of the eye E to be examined, an image may be obtained in which the upper and lower pupils have different widths, as in the anterior segment observation image 523 shown in FIG. 5(f).

<Calculation process of pupil position deviation amount>
FIG. 6 is a flowchart illustrating an example of the processing procedure of the pupil position deviation amount calculation process included in the anterior eye segment alignment process in step S401 of FIG. Specifically, FIG. 6 is a flowchart illustrating an example of a processing procedure for calculating a pupil position shift amount including a process for calculating a pupil center.

First, in step S601, the image acquisition means 211 of the alignment unit 21 obtains an anterior ocular segment image obtained by photographing the anterior ocular segment Ea including the pupil Ep of the eye E, based on the image signal from the image sensor 125. Generate and acquire an observation image (anterior segment image). Note that the image acquisition unit 211 can generate and acquire not only images for anterior segment observation but also fundus images such as fundus observation images and fundus photographed images.

Subsequently, in step S602, the pupil extraction means 212 of the alignment unit 21 extracts the pupil Ep of the eye E from the anterior segment observation image acquired in step S601. The example shown in FIG. 5(d) consists of an upper half partial area 514 (e.g., corresponding to a "first partial area") and a lower half partial area 515 (e.g., equivalent to a "second partial area"). The pupil Ep (the black part located at the center) of the eye E to be examined is extracted from the anterior segment observation image 513. Specifically, in this embodiment, in step S602, the pupil extracting means 212 extracts the outline of the pupil Ep of the eye E to be examined from the anterior segment observation image. In this case, the pupil extraction means 212 extracts the outline of the pupil Ep of the eye E to be examined by performing the following processing.

First, the pupil extracting means 212 binarizes the anterior eye segment observation image acquired in step S601. The threshold value for binarization at this time is, for example, a value determined in advance so that the pupil Ep can be detected with high accuracy. Alternatively, the binarization threshold may be determined from the image, and in this case, the binarization threshold may be determined based on the average brightness or histogram of the entire image or a part of the image, for example. . Furthermore, the pupil extraction means 212 may perform preprocessing on the anterior segment observation image before binarization. As preprocessing, for example, noise reduction processing may be performed using a smoothing filter, or processing may be performed to emphasize the pupils using contrast enhancement processing.

Next, the pupil extracting means 212 labels connected regions in which pixels with a luminance of 0 in the binarized image for anterior eye segment observation are connected, and extracts the largest connected region as the region of the pupil Ep. Note that the method for extracting the pupil Ep region is not limited to the method described here; for example, a connected region whose size is within a predetermined range may be extracted as the pupil Ep region, or a connected region The area of the pupil Ep may be extracted from the vertical and horizontal sizes of the area.

Next, the pupil extraction means 212 extracts a contour in the area of the extracted pupil Ep. Specifically, the pupil extracting means 212 uses the left end and right end of the pupil Ep region as outline candidates for the pupil Ep region at each Y coordinate of the anterior eye segment observation image. Here, in order to prevent false detection of contours, the pupil extraction means 212 may add processing to exclude contour candidates based on some conditions. For example, in order to prevent erroneous detection of eyelids, the pupil extracting means 212 may add a process of excluding that point from the outline candidates when the line connecting the outline candidates is nearly horizontal. Furthermore, for example, in order to prevent erroneous detection of bright spots due to reflection of illumination, the pupil extracting means 212 may add processing for excluding the vicinity of bright spot regions with high brightness from contour candidates. Further, for example, the pupil extracting means 212 may exclude contour candidates based on the positional relationship of points based on the fact that the pupil Ep is approximately circular. For example, the pupil extracting means 212 adds processing to calculate the midpoint between the left end and the right end of the pupil Ep area at each Y coordinate of the anterior segment observation image, and excludes points that are outliers from contour candidates. Alternatively, outliers may be excluded by calculating the distance from the center of gravity of the region of the pupil Ep. As described above, the pupil extracting means 212 extracts the outline of the pupil Ep from the anterior segment observation image. Note that although an example has been shown in which the outline of the pupil Ep is extracted based on the binarized image for anterior eye segment observation, the outline of the pupil Ep may be extracted using other methods. For example, the edge detected by the edge detection process may be extracted as the outline of the pupil Ep, or the pattern of the iris may be detected by some method and the inside thereof may be extracted as the outline of the pupil Ep.

Subsequently, in step S603, the pupil center calculation means 213 of the alignment unit 21 calculates the upper half partial region 514 and the lower half partial region 515 of the anterior eye segment observation image 513 in the example shown in FIG. 5(d), for example. The amount of splitting is calculated from the pupil area split by . Specifically, for example, in the example shown in FIG. 5D, the pupil center calculation means 213 first calculates the midpoints of the left and right midpoints of the pupil outline in the upper half partial region 514 and the lower half partial region 515, respectively. Calculate the average value. Here, the average value of the midpoint on the left and right sides of the pupil outline in the upper half partial region of the image for anterior eye segment observation is taken as the upper center X coordinate, and the pupil outline in the lower half partial region of the anterior eye segment observation image is The average value of the midpoints on the left and right sides of is the lower center X coordinate. In this case, the pupil center calculation means 213 calculates the difference between the upper center X coordinate and the lower center X coordinate as the split amount. Similarly, in the Y direction, the average value of the midpoints (the midpoints between the top and bottom of the pupil outline) in the upper and lower half partial regions is defined as the center Y coordinate.

Subsequently, in step S604, the pupil center calculation means 213 of the alignment unit 21 uses an ellipse model to define the outline of the pupil Ep extracted from each of the upper half partial region and the lower half partial region of the anterior eye segment observation image. Approximate. In the ellipse model used in this embodiment, as will be described later using FIG. 7, the X coordinate of the center of the ellipse is assumed to be zero, so the X coordinate of the contour point of the pupil Ep is converted into a relative value in advance. Specifically, the pupil center calculation means 213 subtracts the upper center X coordinate or the lower center X coordinate calculated in step S603 from the X coordinate of the contour point of the pupil Ep. Thereby, the X coordinate of the contour point of the pupil Ep becomes a relative value from the upper center coordinate or the lower center X coordinate. After performing this processing, approximation to an elliptic model is performed using the method described later with reference to FIG.

Specifically, in this embodiment, the pupil center calculation means 213 performs the following processing in the example of the anterior segment observation image 513 shown in FIG. conduct.
The pupil center calculation means 213 calculates the upper half partial area 514 (for example, the "first partial area") based on the pupil Ep extracted from the lower half partial area 515 (e.g., corresponds to the "second partial area"). The first pupil center in the pupil Ep extracted from the pupil Ep (equivalent to ) is calculated. Specifically, in the example shown in FIG. 6, the pupil center calculation means 213 detects the first pupil center in the pupil Ep extracted from the upper half partial region 514 in step S603. Then, in step S604, the pupil center calculating means 213 corrects the first pupil center detected in step S603 based on the pupil Ep extracted from the lower half partial region 515, thereby determining the first pupil center. Calculate. Note that in the example shown in FIG. 6, the first pupil center is calculated by going through the processes of step S603 and step S604, but the processes of step S603 and step S604 are performed together as one process. It may be an aspect.
Further, the pupil center calculation means 213 calculates the pupil center calculation means 213 based on the pupil Ep extracted from the upper half partial region 514 (corresponding to the "first partial region"), the lower half partial region 515 (for example, the "second partial region"). A second pupil center in the pupil Ep extracted from the pupil Ep (corresponding to the area ") is calculated. Specifically, in the example shown in FIG. 6, the pupil center calculation means 213 detects the second pupil center in the pupil Ep extracted from the lower half partial region 515 in step S603. Then, in step S604, the pupil center calculating means 213 corrects the second pupil center detected in step S603 based on the pupil Ep extracted from the upper half partial region 514, thereby determining the second pupil center. Calculate. Note that in the example shown in FIG. 6, the second pupil center is calculated through the processes of step S603 and step S604, but the processes of step S603 and step S604 are performed together as one process. It may be an aspect.

Subsequently, in step S605, the relative position calculation means 214 of the alignment unit 21 calculates the position in the XYZ directions based on the first pupil center and the second pupil center calculated by the pupil center calculation means 213 in steps S603 and S604. The amount of positional deviation of the pupil Ep is calculated. Specifically, the relative position calculation means 214 calculates the amount of positional deviation of the pupil Ep in the XYZ directions as information indicating the relative position of the pupil Ep of the eye E to be examined with respect to the optical head unit 100 of the imaging unit 10.

First, calculation of the amount of positional deviation of the pupil Ep in the X direction will be described.
The midpoint between the upper center X coordinate and the lower center X coordinate calculated in step S603 is defined as the pupil center X coordinate. In this case, the difference between the pupil center X coordinate and the center X coordinate of the anterior segment observation image is the pupil position deviation X coordinate. Here, the center of the image for observing the anterior segment of the eye is used as the reference coordinate, that is, the coordinate in a state where alignment is correct, but a point other than the center of the image for observing the anterior segment of the eye may be used as the reference coordinate. Next, the relative position calculation means 214 converts the pupil position deviation The amount of positional deviation of the pupil Ep is calculated. For example, if the magnification of the anterior segment measuring optical system 120 is α, the horizontal length of one pixel of the image sensor 125 is s, and the number of pixels of the pupil position deviation X coordinate is n, then the position deviation of the pupil Ep in the X direction is The amount (distance) is ns/α.

Next, calculation of the amount of positional deviation of the pupil Ep in the Y direction will be explained.
The difference between the Y-coordinate of the center of the ellipse model approximated in step S604 and the Y-coordinate of the center of the anterior segment observation image is the pupil position shift Y-coordinate. Note that the conversion from the number of pixels to the actual distance is the same as in the case of the X direction described above, so a description thereof will be omitted.

Next, calculation of the amount of positional deviation of the pupil Ep in the Z direction will be explained.
If the split amount calculated in step S603 is d, and the design value of the Z direction shift amount per split pixel determined by the design of the prism 122 and the anterior eye segment measurement optical system 120 is β, then the position shift amount of the pupil Ep in the Z direction is (distance) is βd.

Through the above processing, the relative position calculating means 214 can calculate the amount of positional deviation of the pupil Ep in the XYZ directions as information indicating the relative position of the pupil Ep of the eye E with respect to the optical head unit 100 of the imaging unit 10. . Note that the calculation of the amount of positional deviation of the pupil Ep in the XYZ directions may be performed using another method. For example, an ellipse model may be used to calculate the amount of positional deviation of the pupil Ep in the X direction. Alternatively, based on the ellipse model approximated in step S604, the viewing angle 501 and the viewing angle 502 shown in FIG. The amount may also be calculated.

When the process in step S605 ends, the process in the flowchart shown in FIG. 6 ends. When the process of the flowchart shown in FIG. 6 is completed, the moving means 215 of the alignment unit 21 performs image capturing based on the amount of positional deviation of the pupil Ep in the XYZ directions (information indicating the relative position in the pupil Ep) calculated in step S605. The optical head section 100 of the section 10 is moved.

<Explanation of ellipse model>
Next, approximation to the elliptic model in step S604 in FIG. 6 will be described.
FIG. 7 is a diagram for explaining the approximation to the ellipse model in step S604 of FIG.

FIG. 7(a) is a diagram similar to FIG. 5(f). That is, the anterior eye segment observation image 710 shown in FIG. 7(a) is similar to the anterior eye segment observation image 523 shown in FIG. 5(f). Further, a partial region 711 in the upper half of the image for anterior eye segment observation 710 shown in FIG. 7(a) is similar to a partial region 524 in the upper half of the image for anterior eye segment observation 523 shown in FIG. 5(f). . A lower half partial region 712 of the anterior eye segment observation image 710 shown in FIG. 7(a) is similar to a lower half partial region 525 of the anterior eye segment observation image 523 shown in FIG. 5(f).

In approximating the pupil of the anterior eye segment observation image 710 shown in FIG. Therefore, there is a problem that a single ellipse cannot be used for accurate approximation. On the other hand, if the upper half partial region 711 and the lower half partial region 712 are approximated to different ellipses, the approximation is performed only using the data of each partial region, which tends to deviate from the original pupil shape. There are challenges. In particular, if the pupil is located above or below the anterior segment observation image 710, or if the pupil is missing due to an eyelid, etc., the pupil may deviate from the ideal elliptical shape due to individual differences in the eye E. If the ellipse is approximated only on one side, the approximation result tends to become unstable in cases where it is out of the range. Therefore, in this embodiment, approximation is performed to a model consisting of two ellipses that share longitudinal parameters of the anterior segment observation image 710. This elliptical model will be explained below.

FIG. 7(b) shows the pupil area (black part located in the center) of the upper half partial area 711 in the anterior segment observation image 710 shown in FIG. 7(a) approximated by the first ellipse 701. FIG. Specifically, the first ellipse 701 approximates the outline of the pupil in the upper half region 711. On the other hand, FIG. 7(c) shows the pupil area (the black part located in the center) of the lower half partial area 712 in the anterior segment observation image 710 shown in FIG. 7(a) with a second ellipse 702. FIG. 3 is a diagram showing an approximation. The second ellipse 702 approximates the outline of the pupil in the lower half region 712. FIG. 7D is a diagram illustrating a first ellipse 701 and a second ellipse 702 superimposed on each other in the anterior segment observation image 710 shown in FIG. 7A. As shown in FIG. 7D, the first ellipse 701 and the second ellipse 702 have different widths in the anterior segment observation image 710, but the vertical parameters (some parameters), that is, the vertical width It can be seen that the Y coordinate of the center is the same. That is, the first ellipse 701 related to the pupil in the upper half partial region 711 reflects the parameters of the pupil in the lower half partial region 712, and the second ellipse related to the pupil in the lower half partial region 712 reflects the parameters of the pupil in the lower half partial region 712. 702 reflects the parameters of the pupil of the upper half partial region 711.

FIG. 7E is a diagram showing an anterior eye segment observation image 720 in a state different from the state of the anterior eye segment observation image 710 shown in FIG. 7A. In the state shown in FIG. 7E, the pupil is shifted toward the upper half partial region 721, so the pupil region of the lower half partial region 722 is small. Also, the pupil is missing due to the eyelid. In such a state, the ellipse approximation result tends to become unstable if only one of the upper half partial region 721 and the lower half partial region 722 is used. In this regard, in the ellipse model of this embodiment, even in the state shown in FIG. The second ellipse 704, which is approximated to the pupil outline of , shares longitudinal parameters. Therefore, in the ellipse model of this embodiment, the approximation is performed using sufficient data, and the pupil of the upper half partial region 721 and the pupil of the lower half partial region 722 are well approximated.

In the ellipse model of this embodiment, the first ellipse that approximates the pupil area of the upper half partial region (e.g., corresponding to the "first partial region") of the anterior segment observation image is the lower half partial region (corresponding to the "first partial region"). For example, it is derived using information on the pupil area (corresponding to the "second partial area"). Similarly, a second ellipse that approximates the pupil area of the lower half partial area of the anterior segment observation image is derived using also information on the pupil area of the upper half partial area. That is, when calculating the pupil center of a pupil detected from a certain partial area, information about the pupil detected from a different partial area is used for correction. If such an ellipse model is used, ellipse approximation is performed based on a wider range of information than ellipse approximation using the pupil area of a partial region on only one side, so the pupil center can be calculated with higher accuracy. Can be done.

<How to derive the ellipse model>
Next, a specific method for deriving the ellipse model of this embodiment will be described. Here, an elliptic model is derived using the least squares method.

A first ellipse that approximates the pupil area of the upper half partial region (corresponding to the "first partial region") of the image for anterior segment observation is defined by the following equation (1), and the image for anterior segment observation is defined by the following equation (1). A second ellipse that approximates the pupil area of the lower half partial area (corresponding to the "second partial area") is defined by the following equation (2).

a 1 in equation ( ₁ ) and a ₂ in equation (2) are the lateral radius of the first ellipse and the lateral radius of the second ellipse, respectively. Furthermore, b in equations (1) and (2) is the vertical radius of the first ellipse and the second ellipse. Furthermore, c _y in equations (1) and (2) is the Y coordinate of the center of the first ellipse and the second ellipse. That is, b and c _y in equations (1) and (2) are parameters shared by the two ellipses, the first ellipse and the second ellipse.

Expanding equation (1) representing the first ellipse and equation (2) representing the second ellipse, and setting the constant term to 1, the following equations (3) and (4) are obtained, respectively. Become.

Next, the error between the pupil contour detected in step S602 in FIG. 6 and these ellipses is determined. Here, the error E is defined as shown in equation (5) below.

U ₁ in equation (6) is a set of indices of pupil contour points in the upper half of the image for anterior segment observation, and U ₂ in equation (7) is a set of indices of pupil contour points in the upper half of the image for anterior segment observation. This is a set of indices of pupil contour points of half the partial region.

Next, according to the concept of the least squares method, conditions under which the error E shown in equation (5) is minimized are determined. The desired condition is when the error E is partially differentiated with respect to the parameters A ₁ , A ₂ , B, and C, and the result becomes zero. If this is expressed in the form of simultaneous equations, it will be as shown in equation (8) below.

In the process of deriving this ellipse model, the part up to deriving the simultaneous equations is performed at the design stage, so it is not performed during the actual pupil detection process.

In step S604 in FIG. 6, the ellipse parameters are calculated by substituting the pupil contour points of each partial region of the anterior segment observation image into the simultaneous equations.

In the ellipse model described above, the horizontal radius of the ellipse is used as an individual parameter, and the vertical radius and center Y coordinate of the ellipse are used as shared parameters, but other ellipse models may be used. For example, the center X coordinates of the first ellipse and the second ellipse may be added as individual parameters. Alternatively, the ellipse angle parameter may be added as an individual parameter or a shared parameter. Further, when the angles of the prisms 122 are different, the way of dividing the shared parameters and individual parameters may be changed. Particularly, in the case of an optical system that splits images for anterior ocular segment observation in the left and right directions, it is desirable to use the horizontal parameters as shared parameters and the vertical parameters as individual parameters.

Further, in this embodiment, the elliptic model is derived using the least squares method, but other methods may be used to derive the ellipse model. For example, with the Hough transform, it is possible to derive a model that shares parameters in the same way as in this embodiment. Further, in this embodiment, an ellipse model is approximated on the anterior segment observation image, but other methods may be used. For example, based on the viewing angle 501 and the viewing angle 502 as shown in FIG. 5(a), pupil contour points may be placed on the XYZ space to approximate an ellipse model on the XYZ space.

The ophthalmologic apparatus 1 according to the embodiment of the present invention described above performs the following processing. The image acquisition unit 211 of the alignment unit 21 of the control unit 20 acquires an image for anterior eye observation (anterior eye segment image) obtained by photographing the anterior eye segment Ea including the pupil Ep of the eye E to be examined. There is. The pupil extraction means 212 of the alignment section 21 of the control section 20 extracts the upper half partial region (corresponding to the "first partial region") and the lower half of the anterior eye segment observation image acquired by the image acquisition means 211. The pupil is extracted from the region (corresponding to the "second partial region"). The pupil center calculation means 213 of the alignment unit 21 of the control unit 20 extracts the pupil from the upper half partial area of the anterior eye segment observation image based on the pupil extracted from the lower half partial area of the anterior eye segment observation image. The first pupil center of the pupil is calculated. Further, the pupil center calculation means 213 of the alignment unit 21 of the control unit 20 calculates the lower half partial area in the anterior eye segment observation image based on the pupil extracted from the upper half partial area in the anterior eye segment observation image. The second pupil center of the pupil extracted from is calculated.
According to this configuration, the center of the pupil Ep of the eye E to be examined can be calculated with high precision, so that the imaging unit 10 (optical head unit 100) of the ophthalmological apparatus 1 can be aligned with the eye E to be examined with high precision. Can be done. As a result, it becomes possible to obtain a suitable photographed image (in this embodiment, a fundus photographed image).

In the embodiment of the present invention described above, the upper half partial area is applied as the first partial area in the anterior eye segment observation image, and the lower half partial area is applied as the second partial area in the anterior eye segment observation image. An example of application was explained. That is, the first partial area and the second partial area in the anterior eye segment observation image are vertically separated areas in the anterior eye segment observation image. In this case, the upper half partial area that is the first partial area and the lower half partial area that is the second partial area in the anterior eye segment observation image are, for example, as shown in FIG. This is a region where E's pupil Ep is photographed using different optical paths. Note that the present invention is not limited to this form. For example, a configuration in which the arrangement of the prism 122 is changed and areas separated left and right in the anterior eye segment observation image are applied as the first partial area and second partial area in the anterior eye segment observation image may also be used. Included in the present invention. Furthermore, for example, by changing the arrangement of the prism 122, regions separated in the diagonal direction in the anterior eye segment observation image are applied as the first partial region and the second partial region in the anterior eye segment observation image. Forms are also included in the invention. Furthermore, in the embodiment of the present invention described above, images for anterior eye segment observation are used that are observed from two directions using a prism effect, but for example, the observation directions may be set to three or more directions. There are three or more partial areas in the partial observation image.

Further, in the embodiment of the present invention described above, an example was shown in which the first partial area and the second partial area are set in one anterior segment observation image, but the present invention is limited to this form. It's not something you can do. The first partial region is set for the first anterior segment observation image obtained by photographing the anterior segment Ea of the subject's eye E multiple times, and the first partial area is set for the second anterior segment observation image. A mode in which the second partial area is set by using the second partial area is also applicable to the present invention. For example, instead of using the prism 122, a case may be considered in which a plurality of image sensors 125 are provided and a plurality of anterior segment observation images obtained by observing the anterior segment Ea of the eye E to be examined from different angles are used. At this time, the present invention also includes a form in which areas indicating the same position of the first anterior segment observation image and the second anterior segment observation image are set as the first partial area and the second partial area. Applicable. Furthermore, a form in which the entire first anterior segment observation image is set as the first partial area and the entire second anterior segment observation image is set as the second partial area is also applicable to the present invention. It is possible.

Furthermore, in the embodiment of the present invention described above, both the first pupil center of the pupil extracted from the first partial area and the second pupil center of the pupil extracted from the second partial area are transferred to the other partial area. An example is shown in which calculation is performed based on pupils extracted from . However, the present invention is not limited to this form. For example, a form in which only the first pupil center of the pupil extracted from the first partial region is calculated based on the pupil extracted from the second partial region is also applicable to the present invention. In particular, the configuration of the embodiment of the present invention described above is characterized in that the upper part of the pupil is particularly prone to chipping due to the lowering of the eyelid of the eye E to be examined. That is, when the pupil in the upper half of the partial region of the anterior segment observation image is approximated by an ellipse, the approximation result is particularly likely to become unstable. Therefore, for example, when approximating the pupil of the upper half partial area in an anterior eye segment observation image with an ellipse, information about the pupil of the lower half partial area is used, whereas when approximating the pupil of the lower half partial area with an ellipse, It is also possible to use only information about the pupils of the lower half partial region.

Further, in the embodiment of the present invention described above, the approximation is made to an elliptic model, but other models may be used. For example, a circular model may be used, or a model developed from an ellipse with the influence of eyelids and bright spots taken into account may be used. Alternatively, instead of using a circular or elliptical model, a center detection method that calculates the center of gravity of the pupil may be used. Regardless of the form, any method is included in the present invention as long as it uses separately extracted pupil information when calculating the center of the extracted pupil.

Further, in the embodiment of the present invention described above, as shown in FIG. 5, the pupil center is calculated based on the anterior segment observation image split by the prism 122, but even with a different hardware configuration, The present invention is applicable. For example, the ophthalmologic apparatus may be configured to include a plurality of cameras, each of which captures images of the eye E from different angles. In this case, the present invention is applicable when detecting the pupil Ep of the eye E from the anterior segment observation images acquired by each camera. That is, when calculating the center of the pupil Ep of the eye E from the image for anterior eye segment observation acquired with a certain camera, the center of the pupil Ep of the eye E is corrected using information on the pupil in the image for anterior eye segment observation acquired with another camera. You can. This is particularly useful when there is a defect in the pupil of the anterior segment observation image obtained with a certain camera. When the eye E to be examined is observed at an angle different from the optical axis of the ophthalmological apparatus, the pupil area may be partially missing due to the influence of the nose, eyelashes, etc. depending on the angle. In such a case, when the present invention is applied, correction can be performed using a complete pupil area in the anterior segment observation image obtained with another camera, so that the pupil center can be calculated with high accuracy.

(Other embodiments)
The present invention provides a system or device with a program that implements one or more of the functions of the embodiments described above via a network or a storage medium, and one or more processors in the computer of the system or device reads and executes the program. This can also be achieved by processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.
This program and a computer-readable storage medium storing the program are included in the present invention.

The embodiments of the present invention described above are merely examples of implementation of the present invention, and the technical scope of the present invention should not be construed as limited by these. It is. That is, the present invention can be implemented in various forms without departing from its technical idea or main features.

The disclosure of the embodiments of the present invention includes the following configurations, methods, and programs.
[Configuration 1]
an acquisition means for acquiring an anterior segment image obtained by photographing the anterior segment of the eye to be examined, including the pupil;
Extracting means for extracting the pupil from a first partial region and a second partial region in at least one anterior segment image acquired by the acquiring means;
center calculating means for calculating a first pupil center of the pupil extracted from the first partial area based on the pupil extracted from the second partial area;
An ophthalmological device characterized by having the following.
[Configuration 2]
The center calculation means detects a first pupil center in the pupil extracted from the first partial area, and applies the detected first pupil center to the pupil extracted from the second partial area. The ophthalmologic apparatus according to configuration 1, wherein the first pupil center is calculated by performing correction based on the ophthalmologic apparatus.
[Configuration 3]
The center calculating means further calculates a second pupil center of the pupil extracted from the second partial area based on the pupil extracted from the first partial area. The ophthalmological device according to configuration 1 or 2.
[Configuration 4]
The center calculation means detects a second pupil center in the pupil extracted from the second partial area, and applies the detected second pupil center to the pupil extracted from the first partial area. The ophthalmologic apparatus according to configuration 3, wherein the second pupil center is calculated by correcting the second pupil center.
[Configuration 5]
5. The ophthalmological apparatus according to any one of configurations 1 to 4, wherein the first partial area and the second partial area are areas in which the pupil is photographed using different optical paths.
[Configuration 6]
5. The ophthalmologic apparatus according to any one of configurations 1 to 4, wherein the first partial area and the second partial area are vertically separated areas in the anterior segment image.
[Configuration 7]
5. The ophthalmologic apparatus according to any one of configurations 1 to 4, wherein the first partial area and the second partial area are areas separated left and right in the anterior segment image.
[Configuration 8]
The first partial region is a region in the first anterior segment image acquired by the acquisition means,
Any one of configurations 1 to 4, wherein the second partial region is a region in a second anterior segment image different from the first anterior segment image, which is obtained by the obtaining means. The ophthalmological device according to item 1.
[Configuration 9]
According to configuration 8, the first partial region and the second partial region are regions indicating the same position of the first anterior eye segment image and the second anterior eye segment image. Ophthalmology equipment.
[Configuration 10]
The first partial region is the entire first anterior segment image,
9. The ophthalmological apparatus according to configuration 8, wherein the second partial region is the entire second anterior segment image.
[Configuration 11]
The center calculation means further calculates a second pupil center of the pupil extracted from the second partial area based on the pupil extracted from the first partial area,
a position calculation means for calculating a relative position of the eye to be examined in the pupil with respect to a photographing unit that photographs the eye to be examined based on the first pupil center and the second pupil center calculated by the center calculation means; The ophthalmologic apparatus according to any one of Configurations 1 to 10, further comprising:
[Configuration 12]
12. The ophthalmological apparatus according to configuration 11, further comprising a moving means for moving the photographing unit based on the relative position calculated by the position calculating means.
[Configuration 13]
The center calculation means further calculates a second pupil center of the pupil extracted from the second partial area based on the pupil extracted from the first partial area,
The center calculation means calculates the first pupil center by approximating the pupil extracted from the first partial region with a first ellipse, and calculates the first pupil center by approximating the pupil extracted from the first partial region. 13. The ophthalmologic apparatus according to any one of configurations 1 to 12, wherein the second pupil center is calculated by approximating the second pupil center with a second ellipse.
[Configuration 14]
14. The ophthalmologic apparatus according to configuration 13, wherein the first ellipse and the second ellipse share some parameters.
[Method 1]
an acquisition step of acquiring an anterior segment image obtained by photographing the anterior segment of the eye to be examined, including the pupil;
an extraction step of extracting the pupil from a first partial region and a second partial region in the at least one anterior segment image acquired in the acquiring step;
a center calculation step of calculating a first pupil center of the pupil extracted from the first partial region based on the pupil extracted from the second partial region;
A method for controlling an ophthalmological device, comprising:
[Program 1]
A program for causing a computer to function as each means of the ophthalmological apparatus according to any one of Configurations 1 to 14.

1: Ophthalmological apparatus, 10: Photographing section, 20: Control section, 21: Alignment section, 22: Focus adjustment section, 23: Light amount adjustment section, 24: Fundus photographing processing section, 25: Storage section, 30: Input section, 40 : display section, 100: optical head section, 150: stage section, 160: base section, 170: face receiving section, 211: image acquisition means, 212: pupil extraction means, 213: pupil center calculation means, 214: relative position calculation Means, 215: Means of transportation

Claims (16)

an acquisition means for acquiring an anterior segment image obtained by photographing the anterior segment of the eye to be examined, including the pupil;
Extracting means for extracting the pupil from a first partial region and a second partial region in at least one anterior segment image acquired by the acquiring means;
center calculating means for calculating a first pupil center of the pupil extracted from the first partial area based on the pupil extracted from the second partial area;
An ophthalmological device characterized by having the following. The center calculation means detects a first pupil center in the pupil extracted from the first partial area, and applies the detected first pupil center to the pupil extracted from the second partial area. The ophthalmologic apparatus according to claim 1, wherein the first pupil center is calculated by performing correction based on the ophthalmological apparatus. The center calculating means further calculates a second pupil center of the pupil extracted from the second partial area based on the pupil extracted from the first partial area. The ophthalmological device according to claim 1. The center calculation means detects a second pupil center in the pupil extracted from the second partial area, and applies the detected second pupil center to the pupil extracted from the first partial area. 4. The ophthalmologic apparatus according to claim 3, wherein the second pupil center is calculated by correcting the second pupil center. The ophthalmologic apparatus according to claim 1, wherein the first partial area and the second partial area are areas in which the pupil is photographed using different optical paths. The ophthalmologic apparatus according to claim 1, wherein the first partial area and the second partial area are vertically separated areas in the anterior segment image. The ophthalmologic apparatus according to claim 1, wherein the first partial area and the second partial area are areas separated left and right in the anterior segment image. The first partial region is a region in the first anterior segment image acquired by the acquisition means,
The ophthalmology clinic according to claim 1, wherein the second partial region is a region in a second anterior segment image different from the first anterior segment image, which is obtained by the obtaining means. Device. 9. The first partial region and the second partial region are regions indicating the same position of the first anterior eye segment image and the second anterior eye segment image. ophthalmological equipment. The first partial region is the entire first anterior segment image,
The ophthalmological apparatus according to claim 8, wherein the second partial region is the entire second anterior segment image. The center calculation means further calculates a second pupil center of the pupil extracted from the second partial area based on the pupil extracted from the first partial area,
a position calculation means for calculating a relative position of the eye to be examined in the pupil with respect to a photographing unit that photographs the eye to be examined based on the first pupil center and the second pupil center calculated by the center calculation means; The ophthalmological device according to claim 1, further comprising: The ophthalmologic apparatus according to claim 11, further comprising a moving means for moving the photographing unit based on the relative position calculated by the position calculating means. The center calculation means further calculates a second pupil center of the pupil extracted from the second partial area based on the pupil extracted from the first partial area,
The center calculation means calculates the first pupil center by approximating the pupil extracted from the first partial region with a first ellipse, and calculates the first pupil center by approximating the pupil extracted from the first partial region. The ophthalmologic apparatus according to claim 1, wherein the second pupil center is calculated by approximating the second pupil center with a second ellipse. The ophthalmologic apparatus according to claim 13, wherein the first ellipse and the second ellipse share some parameters. an acquisition step of acquiring an anterior segment image obtained by photographing the anterior segment of the eye to be examined, including the pupil;
an extraction step of extracting the pupil from a first partial region and a second partial region in the at least one anterior segment image acquired in the acquiring step;
a center calculation step of calculating a first pupil center of the pupil extracted from the first partial region based on the pupil extracted from the second partial region;
A method for controlling an ophthalmological device, comprising: A program for causing a computer to function as each means of the ophthalmologic apparatus according to any one of claims 1 to 14.

Images