Source: https://patents.google.com/patent/JP6349878B2/en
Timestamp: 2019-12-14 13:17:27
Document Index: 627637096

Matched Legal Cases: ['art 22', 'art 70', 'art 3', 'art 6', 'Application No. 2012', 'art 75', 'art 70']

JP6349878B2 - Ophthalmic photographing apparatus, ophthalmic photographing method, and ophthalmic photographing program - Google Patents
Ophthalmic photographing apparatus, ophthalmic photographing method, and ophthalmic photographing program Download PDF
JP6349878B2
JP6349878B2 JP2014073656A JP2014073656A JP6349878B2 JP 6349878 B2 JP6349878 B2 JP 6349878B2 JP 2014073656 A JP2014073656 A JP 2014073656A JP 2014073656 A JP2014073656 A JP 2014073656A JP 6349878 B2 JP6349878 B2 JP 6349878B2
JP2014073656A
JP2015195808A (en
JP2015195808A5 (en
2014-03-31 Priority to JP2014073656A priority Critical patent/JP6349878B2/en
2015-11-09 Publication of JP2015195808A publication Critical patent/JP2015195808A/en
2017-05-25 Publication of JP2015195808A5 publication Critical patent/JP2015195808A5/ja
2018-07-04 Publication of JP6349878B2 publication Critical patent/JP6349878B2/en
The present invention relates to an ophthalmologic imaging apparatus, an ophthalmologic imaging method, and an ophthalmologic imaging program for imaging an eye to be examined.
2. Description of the Related Art Conventionally, an ophthalmic optical coherence tomography (OCT) using low-coherent light or the like is known as an ophthalmologic apparatus that can take a tomographic image of an eye to be examined non-invasively.
For example, as an apparatus using OCT, a combined apparatus of OCT and a fundus camera has been proposed (see Patent Document 1). For example, in such a composite apparatus, an analysis result in which a tomographic image photographed by OCT and a fundus image photographed by a fundus camera (a fundus front image) are associated is displayed on the display unit. Thus, the examiner confirms whether the tomographic image acquired by the OCT is information on the part on the fundus image acquired by the fundus camera. Further, for example, the association between the tomographic image acquired by OCT and the fundus image acquired by the fundus camera is obtained by acquiring the OCT front image from the interference signal acquired by OCT, This is performed by matching a fundus image (a front image of the fundus) captured by a fundus camera.
JP 2013-056274 A
However, when different front-image image capturing methods are used for associating different images, it may be difficult to correlate due to differences in distortion due to the optical system, photographing angle of view, contrast, and the like. As a result, association between different images may not be performed accurately.
In view of the above problems, an object of the present invention is to provide an ophthalmologic photographing apparatus, an ophthalmologic photographing method, and an ophthalmic photographing program capable of accurately associating images.
(1) An ophthalmologic photographing apparatus according to a first aspect of the present disclosure is an ophthalmic photographing apparatus for photographing an eye to be examined, and images the eye to be examined by photographing the eye to be examined using a first imaging method. The second image of the eye to be examined is photographed by photographing the eye to be examined using a first photographing optical system for photographing the first image and a second imaging method different from the first imaging method. A front image of the subject eye by photographing the subject eye using a second imaging optical system for imaging and a third imaging method different from the first imaging method and the second imaging method. A third photographing optical system for obtaining the first image by the third photographing optical system when the first image is obtained by the first photographing optical system, and the second photographing optical system. When acquiring the second image by the system, the third image The imaging optical system acquires a second front image that is a front image different from the first front image, stores the first front image in a memory in association with the first image, and stores the second front image. Control means for storing in the memory in association with the second image, and for the first front image, the second front image, the first image, and the second image stored in the memory, the first front image and And an image processing means for detecting a positional deviation amount with respect to the second front image and associating the first image with the second image based on the positional deviation amount.
(2) An ophthalmologic imaging method according to a second aspect of the present disclosure is an ophthalmologic imaging method for imaging an eye to be examined, and the first eye of the eye to be examined is photographed by imaging the eye to be examined using a first imaging method. A first image acquisition step of acquiring one image and storing it in a memory, and a second image of the eye to be examined by photographing the eye to be examined using a second imaging method different from the first imaging method. A second image acquisition step of acquiring and storing in the memory, and imaging the eye by using a third imaging method different from the first imaging method and the second imaging method. A third image acquisition step for acquiring a front image, wherein the first front image is acquired when the first image is acquired, and the first front image is acquired when the second front image is acquired; 2nd front which is a different front image Acquiring an image, with is stored in the memory in association with said first front image to the first image, a third image acquisition step of storing in a memory in association with the second front image in the second image, in the memory For the stored first front image, the second front image, the first image, and the second image , a positional deviation amount between the first front image and the second front image is detected, And an image processing step of associating the first image with the second image based on a displacement amount.
(3) The ophthalmic imaging program according to the third aspect of the present disclosure is an ophthalmic imaging program that is executed in a control device that controls the operation of the ophthalmic imaging device in order to image the eye to be examined, and is executed by a processor of the control device by being a first image acquisition step of storing the acquired first image of the eye, in the memory by taking the subject's eye by using the first imaging system, said first imaging system Acquires a second image of the subject eye by photographing the subject eye using a different second imaging method , and stores the second image in the memory, the first imaging method, and the second imaging method. A third image acquisition step for acquiring a front image of the eye to be examined by photographing the eye to be examined using a third imaging method different from the imaging method of When acquiring, the first front image is acquired, and when the second front image is acquired, a second front image that is a front image different from the first front image is acquired , and the first front image is acquired. A third image acquisition step of storing the second front image in the memory in association with the first image, and storing the second front image in the memory in association with the second image; the first front image stored in the memory; With respect to the two front images, the first image, and the second image , a positional deviation amount between the first front image and the second front image is detected, and the first image is based on the positional deviation amount. And an image processing step for associating the second image with the second image.
It is the schematic which shows the external appearance of the fundus imaging apparatus which concerns on a present Example. It is a figure which shows the optical system and control system of the fundus imaging apparatus concerning a present Example. It is a figure which shows an example of the screen displayed on the display part which concerns on a present Example. It is an example when the anterior ocular segment image imaged by the image sensor is displayed on the display unit. It is a block diagram which shows the control system which concerns on an Example. It is a figure explaining the alignment detection with respect to a to-be-tested eye. It is a figure which shows an example of the imaging operation which concerns on an Example.
Exemplary embodiments of the present invention will be described with reference to the drawings. In this embodiment, the depth direction of the eye to be examined is the Z direction (optical axis L1 direction), the horizontal component on the plane perpendicular to the depth direction (the same plane as the face of the subject) is the X direction, and the vertical direction. The component is described as the Y direction.
<First overview>
The apparatus 1 includes an interference optical system (OCT optical system) 200, a fundus illumination optical system (hereinafter abbreviated as illumination optical system) 10, and a fundus imaging optical system (hereinafter abbreviated imaging optical system). ) 30 and a control unit (for example, PC 90, control unit 70) (see FIG. 2). The optical axis L2 of the interference optical system 200 and the optical axes L1 of the fundus illumination optical system 10 and the fundus photographing optical system 30 are preferably arranged coaxially by an optical path branching member. Of course, these need not be coaxial.
The interference optical system 200 may be provided in order to obtain a tomographic image of the fundus oculi Ef to be examined by using the optical interference technique. The interference optical system 200 includes a splitter (light splitter), an optical scanning unit, and a photodetector (light receiving element).
A splitter (eg, coupler 104) may be provided to split light from an OCT light source (eg, measurement light source 102) into a measurement optical path and a reference optical path. The measurement optical path may have a configuration (for example, a fiber system, a lens system, etc.) for guiding the measurement light to the fundus oculi Ef. The reference light path may have a configuration for causing the reference light to travel in the apparatus and to interfere with the measurement light.
The optical scanning unit (for example, the scanning unit 108) may be provided to scan the measurement light on the fundus oculi Ef. For example, the optical scanning unit may be arranged in the measurement optical path, and may scan the measurement light irradiated on the eye fundus through the measurement optical path.
The photodetector (for example, the detector 120) may be provided to detect light in which the fundus reflection light from the measurement light from the measurement optical path and the light from the reference optical path are combined. The measurement light from the measurement optical path reflected by the fundus oculi Ef and the reference light from the reference optical path may be combined by a combiner. For example, a beam splitter, a half mirror, a fiber coupler, a circulator, or the like is used for the above-described splitter or combiner.
As the OCT image acquisition unit, the control unit (for example, the PC 90 or the control unit 70) controls the optical scanning unit to scan the measurement light, and acquires at least a tomographic image of the fundus oculi Ef based on the output signal from the photodetector. May be. Further, the control unit controls the optical scanning unit to scan the measurement light, and is a tomographic image of the fundus oculi Ef based on the output signal from the photodetector and a front observation image based on the output signal from the photodetector. One front image (for example, the OCT front image 84) may be acquired.
Regarding acquisition of the tomographic image, for example, the control unit may control the optical scanning unit to scan the measurement light in the transverse direction and acquire a tomographic image of the fundus oculi Ef based on the output signal from the photodetector. The control unit may acquire the tomographic image by controlling the optical scanning unit according to the scanning position set according to the operation signal from the examiner, or the scanning stored in the storage unit (for example, the memory 72). The tomographic image may be acquired by controlling the optical scanning unit according to the position. Note that the scanning position may be changed in the vertical and horizontal directions with respect to the fundus oculi Ef, or may be changed in the rotation direction with respect to the fundus oculi Ef.
In addition, the control unit may acquire the tomographic image by controlling the optical scanning unit according to the scanning pattern set according to the operation signal from the examiner, or according to the scanning pattern stored in the storage unit. A tomographic image may be acquired by controlling the optical scanning unit. Note that the scan pattern can be a line scan or a circle scan. Further, as an example of a scan pattern in which a plurality of different scan lines are arranged, a cross scan, a radial scan, a multi-line scan, a raster scan (map scan), or the like can be considered.
With respect to the first front image, the control unit controls the light scanning unit to scan the measurement light two-dimensionally (for example, raster scan), and is a front-view image of the fundus oculi Ef based on the output signal from the photodetector. A certain first front image (for example, the OCT front image 84) may be acquired.
For example, the control unit may acquire the first front image based on the phase signal of the spectrum signal at each XY position. In this case, the control unit may generate the first front image according to the number of zero cross points in the interference signal (for example, JP 2011-215134 A). The control unit 70 may acquire the first front image based on the intensity signal of the spectrum signal at each XY position.
For example, the control unit may generate the first front image based on the three-dimensional OCT data after generating the three-dimensional OCT data based on the spectrum signal at each position. In this case, the control unit may acquire the first front image by integrating the signal intensity distribution in the depth direction in the Z direction at each XY position of the three-dimensional OCT data. The first front image may be, for example, a retinal surface OCT image or a C-scan image showing a signal intensity distribution at a certain depth position. Note that the first front image is not limited to this, and may be a fundus observation image obtained by performing specific analysis processing on the detection signal from the photodetector.
The acquired first front image may be displayed on the display unit as a live image, for example. In this case, the control unit may alternately perform acquisition of the first front image and acquisition of the first tomographic image corresponding to the set scanning pattern by controlling the optical scanning unit. In this case, the acquisition of the first frontal image and the acquisition of the tomographic image are alternately performed once, and the acquisition of the first tomographic image (one time or Multiple times) may be performed. Further, the acquisition of the first tomographic image may be performed a plurality of times through the acquisition of the first front image at least once.
Note that a tomographic image with high resolution can be acquired by increasing the scanning speed when acquiring a tomographic image from the scanning density when acquiring a front image. Note that a tomographic image may be extracted from three-dimensional OCT data that can be used as original data of the first front image and displayed.
The live image of the first front image may be an image obtained by combining a plurality of continuous first front images (for example, an addition average image). Further, the control unit may perform a plurality of scans at each position and acquire the first front image based on a plurality of spectrum signals. Note that the tomographic image may also be displayed on the display unit as a live image.
Further, the control unit acquires the first front image by controlling the optical scanning unit, and acquires a tomographic image according to the measurement position set on the first front image displayed on the display unit. You may make it do.
The fundus illumination optical system 10 may be provided, for example, for simultaneously illuminating a two-dimensional region on the fundus oculi Ef with illumination light. In this case, the fundus illuminating optical system 10 includes a photographing light source 14 and an observation light source 11, and illuminates a two-dimensional region on the fundus oculi Ef simultaneously with at least any one of the photographing light source 14 and the observation light source 11. Good. Note that the imaging light source 14 and the observation light source 11 may be different from each other, or may be configured by the same light source.
The fundus illuminating optical system 10 may be provided to illuminate the fundus oculi Ef with illumination light through the mirror part 22b of the perforated mirror and the objective lens 25, for example. The illumination light may be at least one of visible light and infrared light. In order to avoid mydriasis, infrared light is preferable. The fundus illumination optical system 10 includes a visible illumination optical system for illuminating the fundus oculi Ef with visible light and a red for illuminating the fundus oculi Ef with infrared light. And an external illumination optical system.
The fundus photographing optical system 30 may be provided, for example, for photographing a front image of the fundus oculi Ef illuminated by illumination light with a two-dimensional image sensor. In this case, the fundus photographing optical system 30 includes a (first) two-dimensional image sensor 35 for photographing the fundus and a (second) two-dimensional image sensor 38 for observing the fundus. A front image of the fundus oculi Ef illuminated with light may be taken. Note that the imaging element for photographing and the imaging element for observation may be configured by different imaging elements, or may be configured by the same imaging element. Each image sensor may be disposed at a position conjugate with the fundus.
The fundus photographing optical system 30 may be provided for photographing a front image of the fundus oculi Ef illuminated by the illumination light of the illumination optical system 10 through the opening 22 a of the perforated mirror 22. The fundus photographing optical system 30 may include a focusing lens 32 that can move in the optical axis direction.
The fundus imaging optical system 30 includes a (first) image sensor (for example, a two-dimensional image sensor 35) for capturing the fundus as a still image, and a second image sensor (for example, a movie image for observing the fundus). , A two-dimensional imaging device 38). The imaging element for photographing and the imaging element for observation may be configured by different imaging elements, or may be configured by the same imaging element,
The fundus illumination optical system 10 and the fundus photographing optical system 30 may be configured as a fundus camera optical system 100 for photographing the fundus of the eye to be examined.
<Display of first front image (for example, OCT front image 84) and second front image (for example, FC front image 92) (for example, see FIG. 3)>
A control part (for example, PC90, control part 70) may be used as a display control part, for example. The display control unit controls display on the display unit (for example, the display unit 75 and the display unit 95). In this case, the display control unit, for example, the first front image based on the output signal from the photodetector of the interference optical system 200 and the fundus oculi Ef based on the imaging signal from the two-dimensional imaging element of the fundus imaging optical system 30. The second front image that is the front observation image may be displayed simultaneously in different display areas. (See FIG. 3).
Thereby, for example, the adjustment of the interference optical system 200 using the first front image and the adjustment of the fundus illumination optical system 10 or the fundus photographing optical system 30 using the second front image can be appropriately executed. Examples of the adjustment of the interference optical system 200 include adjustment of a scanning position, adjustment of a fixation lamp position, focus adjustment, and polarization control. Adjustment of the fundus illumination optical system 10 or the fundus imaging optical system 30 may include alignment or focus adjustment for the eye to be examined. As a result, good tomographic images and good fundus front images (for example, color fundus images and fluorescent fundus images) can be smoothly captured.
Note that the first front image and the second front image are preferably displayed as live images. The examiner can easily grasp the eye or the state of the apparatus while viewing the live image.
The display control unit is based on the first front image based on the output signal from the photodetector of the interference optical system 200 and the image signal from the (second) two-dimensional image sensor 38 for observing the fundus. The second front image that is the front observation image of the fundus oculi Ef may be displayed simultaneously in different display areas.
In the case where the first front image and the second front image are displayed simultaneously in different display areas, the display control unit, for example, displays the first front image and the second front image in different areas on the display screen of the same display unit. A front image may be displayed (see FIG. 3). In this case, for example, the display control unit displays the first front image in the first display region on the display unit, and displays the second front image in a second display region different from the first display region. May be. The first front image and the second front image may be displayed side by side in the vertical and horizontal directions. The first front image and the second front image may be displayed separately. The first front image and the second front image may be displayed in different sizes or may be displayed in the same size. In the following embodiment, the second front image is displayed at a larger display magnification than the first front image. Thus, the examiner can easily confirm the situation such as flare and illumination unevenness. Of course, the first front image may be displayed at a larger display magnification than the first front image. As a result, the examiner can easily confirm the running state of the blood vessel, the abnormal site, and the like. Further, regarding the display of the first front image and the second front image, the display magnification may be set based on the shooting angle of view. That is, the display magnification may be set according to the shooting angle of view of the optical system. For example, when the shooting angle of view of the first front image is 30 ° and the shooting angle of view of the second front image is 45 °, the second front image is 1.5 times the first front image. May be displayed.
In addition, for example, the display control unit displays the first front image on one of the plurality of display units (for example, the display unit 95), and displays the second front image on the plurality of display units (for example, the display unit 75). You may make it display.
When the first front image and the second front image are displayed, at least a part of the imaging region on the fundus oculi Ef may be common (see FIG. 3). In this case, the optical axis of the interference optical system 200 and the optical axes of the fundus illuminating optical system 10 and the fundus photographing optical system 30 are arranged coaxially, so that the imaging areas in the vicinity of the optical axes are at least the same imaging area. Is set.
The display control unit may be able to superimpose the second front image on the first front image, or may be able to superimpose the first front image on the second front image. For example, in a state where the first front image and the second front image are displayed in different display areas, at least one front image is superimposed and displayed by the other front image.
The display control unit includes a first display area (for example, a display area 300) in which displays related to image acquisition using the interference optical system 200 are integrated, a fundus illumination optical system 10, and a fundus photographing optical system 30. The second display area (for example, the display area 400) in which the display related to the used image acquisition is integrated may be displayed separately (see FIG. 3).
As a result, for example, the display related to OCT and the display related to fundus frontal image capturing (for example, fundus camera) are displayed separately, so that the examiner can smoothly set each condition. Can do.
For example, a first display area may be provided on the left side of the display unit, and a second display area may be provided on the right side of the display unit. For example, it may be reversed right and left, or may be divided vertically.
In the first display area, for example, in addition to the first front image, a tomographic image, an imaging condition related to the interference optical system, and the like may be displayed. Note that, as an example of an imaging condition regarding the interference optical system 200, a scanning position by an optical scanning unit may be used. The scanning position may be changed based on an operation signal from the operation unit. A display area for changing the optical path difference between the measurement light and the reference light may be provided, and the optical path difference may be adjusted based on an operation signal from the display area.
In the second display area, for example, in addition to the second front image, imaging conditions regarding at least one of the fundus illumination optical system 10 or the fundus imaging optical system 20 are displayed. The photographing conditions include the position of the focusing lens, the amount of light taken by the photographing light source 14, selection of whether the low light amount photographing mode or the normal light amount photographing mode, whether the small pupil photographing mode is performed or whether the normal small pupil photographing mode is set. It is possible to select at least one of them.
The display unit may be a touch panel, and the shooting conditions may be changed based on an operation signal from the touch panel. Of course, the display unit is not limited to the touch panel, and the imaging condition may be changed based on a scanning signal from an interface such as a mouse or a keyboard via display on the display unit.
The apparatus 1 may be provided with an index projection optical system for projecting an index on the eye to be examined. As the index projection optical system, an index projection optical system (for example, the focus index projection optical system 40) for projecting a focus index (for example, a split index) on the fundus of the eye to be examined, and an index for projecting an alignment index to the eye to be examined. At least one of a projection optical system (for example, an infrared light source 55) and an index projection optical system for projecting a fixation target onto the eye to be examined can be considered.
The reflected light from the eye to be examined by the index projection optical system may be imaged by a two-dimensional imaging device (for example, two-dimensional imaging device 38) of the fundus imaging optical system 30. In this case, the display control unit may display an index based on the imaging signal from the two-dimensional imaging element on the second front image (for example, S1 · S2, W1 · W2). In addition, as a display method of the index, for example, in addition to a method of directly displaying the captured index, a method of superimposing an electronic display (for example, colored display) on the index, and further, a position detection result of the index An indicator display based on this is conceivable.
The display control unit may electronically display a scanning line (for example, the scanning line SL) indicating the measurement position of the tomographic image displayed on the display unit on the first front image. This makes it possible to set the scanning position using an OCT front image that allows easy confirmation of the blood vessel state and abnormal site.
Note that the scanning line may be moved based on an operation signal from an operation unit operated by an examiner. The control unit may acquire a tomographic image according to the scanning position moved by the examiner. Note that the display control unit does not have to electronically display the scanning lines on the second front image side.
The display control unit displays an index based on the imaging signal from the two-dimensional image sensor on the second front image, and on the first front image, scans indicating the measurement position of the tomographic image displayed on the display unit. The line may be displayed electronically. As a result, since the index (for example, focus index, alignment index, fixation target) displayed on the second front image and the scanning line are not superimposed, the examiner can easily make various adjustments.
<Display of anterior segment image>
The apparatus 1 may be provided with an anterior ocular segment observation optical system 60 for observing an anterior ocular segment image of the eye to be examined. Therefore, the display control unit may simultaneously display the anterior segment image acquired by the anterior segment observation optical system 60, the tomographic image, the first front image, and the second front image.
As described above, the apparatus 1 may be provided with an index projection optical system for projecting an index (for example, a focus index or an alignment index) on the eye to be examined. In this case, the display control unit displays a scanning line indicating the measurement position of the tomographic image displayed on the display unit based on the output signal from the photodetector or the imaging signal from the two-dimensional imaging element of the fundus imaging optical system 30. While the first frontal observation image of the fundus oculi Ef is displayed, the first image of the fundus oculi Ef including the index based on the image pickup signal from the two-dimensional image pickup device is displayed based on the image pickup signal from the two-dimensional image pickup device of the fundus photographing optical system 30. Two front observation images may be displayed. The display control unit may simultaneously display the first front observation image and the second front image in different display areas.
Accordingly, since the scanning line is not superimposed on the second front observation image including the index, the examiner can easily perform the adjustment using the index. In this case, an index may be displayed in the first front observation image. This is because the first front observation image mainly sets the scanning position, and the presence or absence of the index is relatively unnoticeable.
Note that the first front observation image and the second front observation image may be acquired by the same optical system and imaging device, or may be acquired by different optical systems.
When acquired by the same optical system and image sensor, the control unit may control the indicator projection optical system (for example, the light source 41 and the light source 55) to blink the indicator. In this case, the display control unit acquires the front observation image when the light is turned off as the first observation image and displays it on the display unit, and acquires the front observation image when the light is turned on as the second observation image and displays it on the display unit. You may do it.
Note that the present embodiment is not limited to the above, and the above-described control can be performed in other optical systems. For example, the fundus illumination optical system 10 may be an optical system for illuminating the fundus of the eye to be examined with illumination light. The fundus photographing optical system 30 may be an optical system for photographing a front image of the fundus illuminated by illumination light with a light receiving element.
The fundus illumination optical system 10 and the fundus photographing optical system 30 are configured to simultaneously illuminate a two-dimensional region of the fundus as described above and photograph a fundus front image with a light receiving element (for example, a two-dimensional imaging element). May be. Further, the fundus illumination optical system 10 and the fundus photographing optical system 30 may be, for example, an SLO. The SLO can photograph a fundus front image by, for example, laser scanning the fundus and receiving the reflected light with a light receiving element (for example, a point sensor).
In this case, the display control unit displays differently the first front image based on the output signal from the photodetector and the second front image that is a front observation image of the fundus oculi Ef based on the light reception signal from the light receiving element. It may be displayed simultaneously in the area. Of course, the above-described techniques can also be applied to this configuration.
Thereby, for example, the adjustment of the interference optical system 200 using the first front image and the adjustment of the fundus illumination optical system 10 or the fundus photographing optical system 30 using the second front image can be appropriately executed.
<Second outline>
<Operation for positioning using front image>
The photographing operation of the apparatus having the above configuration will be described. When the shooting start switch is operated, the control unit 70 starts shooting an image. Of course, a configuration may be adopted in which shooting is automatically started after the setting of shooting conditions is completed. For example, in the photographing operation, the control unit 70 obtains the first front image by the third photographing optical system when obtaining the first image by the first photographing optical system. For example, when acquiring the second image with the second imaging optical system, the control unit 70 acquires the second front image that is a front image different from the first front image with the third imaging optical system.
For example, the first image is an image of the eye to be examined that is captured using the first imaging method. For example, the second image is an image of the eye to be examined that is captured using a second imaging method that is different from the first imaging method. For example, the front images (first front image and second front image) are front images of the subject's eye photographed using a third imaging method different from the first imaging method and the second imaging method.
For example, as the first imaging method and the second imaging method, a configuration using an interference optical system (OCT optical system) 200, an SLO optical system, a fundus camera optical system 100, an anterior ocular segment observation optical system 60, a perimeter, or the like. Is mentioned.
For example, the SLO optical system includes an optical scanner that two-dimensionally scans the fundus of measurement light (for example, infrared light) emitted from a light source, and a confocal aperture that is disposed at a substantially conjugate position with the fundus. It has a light receiving element that receives fundus reflected light and has a so-called laser scanning opthalmoscope (SLO) device configuration. When acquiring the fundus front image, the fundus front image (SLO image) is acquired based on the light reception signal output from the light receiving element of the SLO.
For example, the fundus camera optical system 100 illuminates the fundus of the subject's eye with illumination light and captures a front image of the fundus illuminated with the illumination light. When the fundus camera optical system 100 is applied as a method for capturing the second image, visible light is used as illumination light, and a color fundus image is captured as the second image. In this case, for example, the second imaging optical system includes a visible illumination optical system for illuminating the fundus of the subject's eye with visible light and a visible image for capturing a front image of the fundus of the subject's eye illuminated with visible light. And taking a color fundus image of the eye to be examined as the second image. For example, the color fundus image may be configured to use a fluorescence image acquired using fundus illumination light specified at a predetermined wavelength.
For example, as the third imaging method, a configuration using a fundus camera optical system 100, an SLO optical system, or the like can be given. In addition, when applying the fundus camera optical system 100 as a method for capturing a front image, infrared light is used as illumination light, and an infrared fundus image is captured as a front image. In this case, for example, the third imaging optical system captures an infrared illumination optical system for illuminating the fundus of the subject's eye with infrared light and a front image of the fundus of the subject's eye illuminated with the infrared light. And taking an infrared fundus image of the subject's eye as front images (first front image and second front image described later).
When each image is acquired, the control unit 70 performs image analysis processing. For example, the control unit 70 detects the amount of positional deviation between the first front image and the second front image, and associates the first image with the second image based on the amount of positional deviation.
As described above, the first image and the second image can be associated with each other easily and accurately by associating the first image with the second image using the front images having the same shooting conditions. In addition, when an infrared fundus image is used as the front image (first front image and second front image), the infrared fundus image can be acquired at high speed, so when the first image is acquired, The alignment front image at the time of acquiring the first image can be acquired quickly. Further, when the second image is acquired, the alignment front image at the time of acquiring the second image can be acquired quickly. For this reason, there is almost no displacement in the positional relationship between the front image and the other images (first image and second image). That is, since it is not necessary to associate the positional relationship between the front image and another image again, the amount of positional deviation between the first front image and the second front image is defined as the amount of positional deviation between the first image and the second image. Can be applied. For this reason, it is not necessary to perform a plurality of associations between the images, and the first image and the second image can be easily and accurately associated with each other.
Hereinafter, an example of a process in which the control unit 70 detects the positional deviation amount between the first front image and the second front image and associates the first image with the second image based on the positional deviation amount. Show. For example, a tomographic image is used as the first image. For example, a color fundus image is used as the second image. For example, an infrared fundus image is used as the front image. In this case, for example, the control unit 70 associates the tomographic image of the fundus of the eye to be examined with the color fundus image of the eye to be examined on the fundus image of the color of the eye to be examined that has been photographed by the second photographing optical system. The acquisition position of the tomographic image of the fundus of the eye to be examined photographed by the first photographing optical system is specified. Based on the specified acquisition position, the control unit 70 superimposes a display indicating the acquisition position at which the tomographic image of the fundus of the subject eye is acquired on the color fundus image of the eye to be examined. By adopting such a configuration, the examiner can accurately grasp the correspondence between the color fundus image and the tomographic image, which is excellent in resolution and contrast and suitable for finding the lesion from the entire fundus. It is possible to make a useful diagnosis for.
In the case of acquiring an image as in the above example, the control unit 70 acquires the first front image by the third imaging optical system. After acquiring the first front image, the control unit 70 acquires the first image using the first imaging optical system. After acquiring the first image, the control unit 70 acquires the second front image by the third imaging optical system. After acquiring the second front image, the control unit 70 acquires the second image by the second imaging optical system. By performing a series of image acquisition in such an acquisition order, the fundus of the eye to be examined can be easily photographed. That is, if the color fundus image is taken first, the eye to be examined is reduced in pupil size, making it difficult for the measurement light for tomographic image photography to enter the eye and obtaining the tomographic image 83 is difficult. However, by obtaining a series of images in the order as described above, the tomographic image 83 and the color fundus image can be easily acquired. Further, even when it takes a long time to acquire a tomographic image by acquiring a front image used for association between the acquisition of a tomographic image 83 and the acquisition of a color fundus image, By using the first infrared fundus image and the second infrared fundus image at the time of acquiring the color fundus image, the tomographic image and the color fundus image can be easily and accurately associated with each other.
In addition, when a tomographic image is captured a plurality of times by acquiring a front image used for association between the acquisition of a tomographic image and the acquisition of a color fundus image, a plurality of color fundus images are captured. It is possible to easily and accurately associate a plurality of tomographic images and color fundus images without performing the above. For example, the control unit 70 acquires an infrared fundus image when acquiring a plurality of tomographic images. The control unit 70 calculates the amount of positional deviation between each infrared fundus image acquired when acquiring a plurality of tomographic images and the second infrared fundus image acquired when acquiring a color fundus image. The control unit 70 associates a plurality of tomographic images and one color fundus image based on the positional deviation amount between each infrared fundus image and the second infrared fundus image. Accordingly, it is not necessary to acquire a color fundus image every time a tomographic image is acquired, and it is possible to reduce the number of times that the eye is irradiated with the visible light every time a color fundus image is taken. Can be reduced. Note that multiple tomographic image capturing may be configured to capture tomographic images with the same scanning pattern, or with different scanning patterns (eg, line scan, cross scan, map scan, etc.). The tomographic image may be taken.
Note that the technology disclosed in the present invention is not limited to the apparatus described in this embodiment. For example, ophthalmic imaging software (program) that performs the functions of the above embodiments is supplied to a system or apparatus via a network or various storage media. A computer of the system or apparatus (for example, a CPU) can also read and execute the program.
For example, the ophthalmologic imaging program is executed in the processor of the control device that controls the operation of the ophthalmologic imaging apparatus to image the eye to be examined. For example, the ophthalmologic photographing program obtains a first image of the eye to be examined by photographing the eye to be examined using the first imaging method, and a second imaging different from the first imaging method. A second image acquisition step of acquiring a second image of the eye to be inspected by imaging the eye to be inspected using the method, and a third imaging method different from the first imaging method and the second imaging method. A third image acquisition step for acquiring a front image of the eye to be inspected by photographing the optometer, wherein the first front image is acquired and the second front image is acquired when acquiring the first image; In addition, a third image acquisition step of acquiring a second front image, which is a front image different from the first front image, a positional deviation amount between the first front image and the second front image is detected, and the positional deviation amount is detected. Based on the first image and the second image An image processing step of applying, may be configured to include a.
As shown in FIG. 1A, the apparatus main body 1 of the present embodiment mainly includes, for example, a base 4, a photographing unit 3, a face support unit 5, and an operation unit 74. The photographing unit 3 may house an optical system described later. The imaging unit 3 may be provided so as to be movable in a three-dimensional direction (XYZ) with respect to the eye E. The face support unit 5 may be fixed to the base 4 in order to support the subject's face.
The imaging unit 3 may be moved relative to the eye E in the left-right direction, the up-down direction (Y direction), and the front-rear direction by the XYZ drive unit 6. Note that the photographing unit 3 may be moved in the left-right direction (X direction) and the front-rear (working distance) direction (Z direction) with respect to the left and right eyes by the movement of the movable table 2 with respect to the base 4.
The joystick 74a is used as an operation member operated by the examiner to move the photographing unit 3 with respect to the eye E. Of course, it is not limited to the joystick 74a, and may be another operation member (for example, a touch panel, a trackball, etc.).
For example, the operation unit once transmits an operation signal from the examiner to the control unit 70. In this case, the control unit 70 may send an operation signal to the personal computer 90 described later. In this case, the personal computer 90 sends a control signal corresponding to the operation signal to the control unit 70. Upon receiving the control signal, the control unit 70 performs various controls based on the control signal.
For example, the movable table 2 is moved relative to the eye to be examined by operating the joystick 74a. Further, by rotating the rotary knob 74b, the XYZ driving unit 6 is driven in Y and the photographing unit 3 is moved in the Y direction. In addition, the structure which the imaging | photography part 3 is moved with respect to the eye to be examined by the XYZ drive part 6 when the joystick 74a is operated without providing the moving stand 2 may be sufficient.
The imaging unit 3 may be provided with, for example, a display unit 75 (for example, the examiner side). The display unit 75 may display, for example, a fundus observation image, a fundus photographing image, and an anterior eye observation image.
In addition, the apparatus main body 1 of this embodiment is connected to a personal computer (hereinafter, PC) 90. For example, a display unit 95 and operation members (keyboard 96, mouse 97, etc.) may be connected to the PC 90.
As shown in FIG. 2, the optical system of this embodiment mainly includes an illumination optical system 10, a photographing optical system 30, and an interference optical system 200 (hereinafter also referred to as an OCT optical system) 200. Further, the optical system may include a focus index projection optical system 40, an alignment index projection optical system 50, and an anterior ocular segment observation optical system 60. The illumination optical system 10 and the photographing optical system 30 are used as a fundus camera optical system (FC optical system) 100 for obtaining a color fundus image by photographing the fundus with visible light (for example, a non-mydriatic state). The imaging optical system 30 captures a fundus image of the eye to be examined. The OCT optical system 200 obtains a tomographic image of the fundus of the eye to be examined non-invasively using an optical interference technique.
Hereinafter, an example of the optical arrangement of the fundus camera optical system 100 will be shown.
<Illumination optics>
The illumination optical system 10 includes, for example, an observation illumination optical system and a photographing illumination optical system. The photographing illumination optical system mainly includes a photographing light source 14, a condenser lens 15, a ring slit 17, a relay lens 18, a mirror 19, a black spot plate 20, a relay lens 21, a perforated mirror 22, and an objective lens 25. The photographing light source 14 may be a flash lamp, an LED, or the like. The black spot plate 20 has a black spot at the center. The imaging light source 14 is used, for example, for imaging the fundus of the subject's eye with light in the visible range.
The observation illumination optical system mainly includes an observation light source 11, an infrared filter 12, a condenser lens 13, a dichroic mirror 16, and an optical system from the ring slit 17 to the objective lens 25. The observation light source 11 may be a halogen lamp, an LED, or the like. The observation light source 11 is used, for example, for observing the fundus of the eye to be examined with light in the near infrared region. The infrared filter 12 is provided to transmit near infrared light having a wavelength of 750 nm or more and cut light having a wavelength band shorter than 750 nm. The dichroic mirror 16 is disposed between the condenser lens 13 and the ring slit 17. The dichroic mirror 16 has a characteristic of reflecting light from the observation light source 11 and transmitting light from the imaging light source 14. Note that the observation light source 11 and the imaging light source 14 may be arranged in series on the same optical axis.
In the photographic optical system 30, for example, an objective lens 25, a photographing aperture 31, a focusing lens 32, an imaging lens 33, and an image sensor 35 are mainly disposed. The photographing aperture 31 is located in the vicinity of the aperture of the perforated mirror 22. The focusing lens 32 is movable in the optical axis direction. The image sensor 35 can be used for photographing having sensitivity in the visible range. The photographing aperture 31 is disposed at a position substantially conjugate with the pupil of the eye E with respect to the objective lens 25. The focusing lens 32 is moved in the optical axis direction by a moving mechanism 49 including a motor.
A dichroic mirror 37 having a characteristic of reflecting part of infrared light and visible light and transmitting most of visible light is disposed between the imaging lens 33 and the image sensor 35. In the reflection direction of the dichroic mirror 37, an imaging device for observation 38 having sensitivity in the infrared region is disposed. Instead of the dichroic mirror 34, a flip-up mirror may be used. For example, the flip-up mirror is inserted into the optical path during fundus observation, and is retracted from the optical path during fundus imaging.
A dichroic mirror (wavelength selective mirror) 24 that can be inserted and removed as an optical path branching member is provided obliquely between the objective lens 25 and the perforated mirror 22. The dichroic mirror 24 reflects the wavelength light of the OCT measurement light and the wavelength light (for example, center wavelength 940 nm) of the alignment index projection optical system 50 and the anterior segment illumination light source 58. Further, the dichroic mirror 24 has a characteristic of transmitting a wavelength of 800 nm or less including a light source wavelength (for example, a center wavelength of 780 nm) of wavelength light for fundus observation illumination. At the time of shooting, the dichroic mirror 24 is flipped up by the insertion / removal mechanism 66 and retracts out of the optical path. The insertion / removal mechanism 66 can be composed of a solenoid and a cam.
Further, the optical path correction glass 28 is disposed on the image pickup element 35 side of the dichroic mirror 24 so as to be able to be flipped up by driving the insertion / removal mechanism 66. When the optical path is inserted, the optical path correction glass 28 has a role of correcting the position of the optical axis L1 shifted by the dichroic mirror 24.
The light beam emitted from the observation light source 11 is converted into an infrared light beam by the infrared filter 12 and reflected by the condenser lens 13 and the dichroic mirror 16 to illuminate the ring slit 17. The light transmitted through the ring slit 17 reaches the perforated mirror 22 through the relay lens 18, the mirror 19, the black spot plate 20, and the relay lens 21. The light reflected by the perforated mirror 22 passes through the correction glass 28 and the dichroic mirror 24, and once converges near the pupil of the eye E to be examined by the objective lens 25, and then diffuses to illuminate the fundus of the eye to be examined.
Reflected light from the fundus is imaged through the objective lens 25, the dichroic mirror 24, the correction glass 28, the aperture of the perforated mirror 22, the imaging aperture 31, the focusing lens 32, the imaging lens 33, and the dichroic mirror 37. An image is formed on the element 38. The image sensor 38 is disposed at a conjugate position with the fundus. The output of the image sensor 38 is input to the control unit 70, and the control unit 70 displays a fundus observation image (OCT front image 82) of the eye to be inspected imaged by the image sensor 38 on the display unit 75 (see FIG. 3). ).
Further, the light beam emitted from the photographing light source 14 passes through the dichroic mirror 16 via the condenser lens 15. Thereafter, the fundus is illuminated with visible light through the same optical path as the illumination light for fundus observation. Then, the reflected light from the fundus is imaged on the image sensor 35 through the objective lens 25, the opening of the perforated mirror 22, the imaging aperture 31, the focusing lens 32, and the imaging lens 33.
The focus index projection optical system 40 mainly includes an infrared light source 41, a slit index plate 42, two declination prisms 43, a projection lens 47, and a spot mirror 44 obliquely provided in the optical path of the illumination optical system 10. The two declination prisms 43 are attached to the slit target plate 42. The spot mirror 44 is provided obliquely in the optical path of the illumination optical system 10. The spot mirror 44 is fixed to the tip of the lever 45. The spot mirror 44 is normally inclined to the optical axis, but is retracted out of the optical path by rotation of the rotary solenoid 46 at a predetermined timing before photographing.
The spot mirror 44 is arranged at a position conjugate with the fundus of the eye E. The light source 41, the slit indicator plate 42, the deflection prism 43, the projection lens 47, the spot mirror 44 and the lever 45 are moved in the optical axis direction by the moving mechanism 49 in conjunction with the focusing lens 32. Further, the light flux of the slit index plate 42 of the focus index projection optical system 40 is reflected by the spot mirror 44 via the deflection prism 43 and the projection lens 47, and then the relay lens 21, the perforated mirror 22, the dichroic mirror 24, The light is projected onto the fundus of the eye E through the objective lens 25. When the fundus is not focused, the index images S1 and S2 are projected onto the fundus in a state of being separated according to the shift direction and shift amount. On the other hand, when the focus is achieved, the index images S1 and S2 are projected onto the fundus in a matched state (see FIG. 3). The index images S1 and S2 are taken together with the fundus image by the image sensor 38.
In the alignment index projection optical system 50 for projecting the alignment index beam, a plurality of infrared light sources are arranged at 45 degree intervals on a concentric circle with the photographing optical axis L1 as the center, as shown in the diagram in the upper left dotted line in FIG. Has been placed. The ophthalmologic photographing apparatus in the present embodiment mainly includes a first target projection optical system (0 degrees and 180) and a second target projection optical system. The first target projection optical system has an infrared light source 51 and a collimating lens 52. The second target projection optical system is arranged at a position different from the first index projection optical system and has six infrared light sources 53. The infrared light sources 51 are arranged symmetrically with respect to a vertical plane passing through the photographing optical axis L1. In this case, the first index projection optical system projects an index at infinity on the cornea of the eye E from the left-right direction. The second index projection optical system is configured to project a finite index on the cornea of the eye E from the vertical direction or the oblique direction. In FIG. 2, for convenience, the first index projection optical system (0 degrees and 180 degrees) and only a part of the second index projection optical system (45 degrees and 135 degrees) are shown. .
An anterior ocular segment observation (imaging) optical system 60 for imaging the anterior ocular segment of the eye to be inspected has a dichroic mirror 61, a diaphragm 63, a relay lens 64, a two-dimensional imaging element (light receiving element: hereinafter) on the reflection side of the dichroic mirror 24. (It may be abbreviated as the image sensor 65). The image sensor 65 has infrared sensitivity. The imaging element 65 also serves as an imaging means for detecting the alignment index, and the anterior segment illuminated by the anterior segment illumination light source 58 that emits infrared light and the alignment index are imaged. The anterior segment illuminated by the anterior segment illumination light source 58 is received by the image sensor 65 from the objective lens 25, the dichroic mirror 24, and the dichroic mirror 61 through the optical system of the relay lens 64. Further, the alignment light beam emitted from the light source of the alignment index projection optical system 50 is projected onto the eye cornea to be examined. The cornea reflection image is received (projected) on the image sensor 65 through the objective lens 25 to the relay lens 64.
The output of the two-dimensional image sensor 65 is input to the control unit 70, and the anterior segment image captured by the two-dimensional image sensor 65 is displayed on the display unit 75 as shown in FIGS. The anterior ocular segment observation optical system 60 also serves as a detection optical system for detecting the alignment state of the apparatus main body with respect to the eye to be examined.
In addition, in the vicinity of the hole of the perforated mirror 22, there are two infrared light sources (in this embodiment, for forming an optical alignment index (working dot W1) on the cornea of the subject's eye). However, the present invention is not limited to this. ) 55 is arranged. The light source 55 may have a configuration in which infrared light is guided to an optical fiber having an end face disposed in the vicinity of the perforated mirror 22. The corneal reflected light from the light source 55 is imaged on the imaging surface of the imaging element 38 when the working distance between the subject eye E and the imaging unit 3 (apparatus body) is appropriate. As a result, the examiner can finely adjust the alignment using the working dots formed by the light source 55 while the fundus image is displayed on the monitor 8.
Returning to FIG. The OCT optical system 200 has a device configuration of a so-called ophthalmic optical coherence tomography (OCT) and takes a tomographic image of the eye E. The OCT optical system 200 divides light emitted from the measurement light source 102 into measurement light (sample light) and reference light by a coupler (light splitter) 104. The OCT optical system 200 guides measurement light to the fundus oculi Ef of the eye E and guides reference light to the reference optical system 110. The measurement light reaches the scanning unit 108 via the collimator lens 123 and the focus lens 124, and the reflection direction is changed by driving two galvanometer mirrors, for example. Then, the measurement light reflected by the scanning unit 108 is reflected by the dichroic mirror 24 and then condensed on the fundus of the eye to be examined through the objective lens 25. Interference light obtained by combining the measurement light reflected by the fundus oculi Ef and the reference light is received by the detector (light receiving element) 120.
The detector 120 detects an interference state between the measurement light and the reference light. In the case of Fourier domain OCT, the spectral intensity of the interference light is detected by the detector 120, and a depth profile (A scan signal) in a predetermined range is obtained by Fourier transform on the spectral intensity data. Examples include Spectral-domain OCT (SD-OCT) and Swept-source OCT (SS-OCT). In the case of Spectral-domain OCT (SD-OCT), for example, a broadband light source is used as the light source 102, and a spectrometer (spectrometer) is used as the detector 120. In the case of Swept-source OCT, for example, a variable wavelength light source is used as the light source 102, and a single photodiode is used as the detector 120 (balance detection may be performed). Moreover, Time-domain OCT (TD-OCT) may be used.
The scanning unit 108 scans light emitted from the measurement light source on the fundus of the eye to be examined. For example, the scanning unit 108 scans the measurement light two-dimensionally (XY direction (transverse direction)) on the fundus. The scanning unit 108 is disposed at a position substantially conjugate with the pupil. The scanning unit 108 is, for example, two galvanometer mirrors, and the reflection angle thereof is arbitrarily adjusted by the driving unit 151.
Thereby, the reflection (advance) direction of the light beam emitted from the light source 102 is changed, and is scanned in an arbitrary direction on the fundus. Thereby, the imaging position on the fundus oculi Ef is changed. The scanning unit 108 may be configured to deflect light. For example, in addition to a reflective mirror (galvano mirror, polygon mirror, resonant scanner), an acousto-optic device (AOM) that changes the traveling (deflection) direction of light is used.
The reference optical system 110 generates reference light that is combined with reflected light acquired by reflection of measurement light at the fundus oculi Ef. The reference optical system 110 may be a Michelson type or a Mach-Zehnder type.
The reference optical system 110 may change the optical path length difference between the measurement light and the reference light by moving the optical member in the reference light path. For example, the reference mirror 131 is moved in the optical axis direction. The configuration for changing the optical path length difference may be arranged in the measurement optical path of the measurement optical system.
More specifically, the reference optical system 110 mainly includes, for example, a collimator lens 129, a reference mirror 131, and a reference mirror driving unit 150. The reference mirror driving unit 150 is disposed in the reference optical path and is configured to be movable in the optical axis direction so as to change the optical path length of the reference light. The light is reflected by the reference mirror 131 and returned to the coupler 104 again and guided to the detector 120. As another example, the reference optical system 110 is formed by a transmission optical system (for example, an optical fiber), and guides the light from the coupler 104 to the detector 120 by transmitting the light without returning.
Next, the control system of this embodiment will be described with reference to FIG. As shown in FIG. 6, the control unit 70 of the present embodiment includes an imaging element 65 for anterior ocular segment observation, an imaging element 38 for infrared fundus observation, a display unit 75, an operation unit 74, a USB 2. A 0 standard HUB 71 is connected to each light source (not shown), various actuators (not shown), and the like. The USB 2.0 HUB 71 is connected with an image sensor 35 built in the apparatus main body 1 and a PC (personal computer) 90.
The PC 90 includes a CPU 91 as a processor, an operation input unit (for example, a mouse and a keyboard), a memory (nonvolatile memory) 72 as a storage unit, and a display unit 95. The CPU 91 may control the apparatus main body 1. The memory 72 is a non-transitory storage medium that can retain stored contents even when power supply is interrupted. For example, a hard disk drive, flash ROM, USB memory detachably attached to the PC 90, an external server, or the like can be used as the memory 72. The memory 72 stores an imaging control program for controlling imaging of front images and tomographic images by the apparatus main body (ophthalmic imaging apparatus) 1.
Further, the memory 72 stores an ophthalmic analysis program for using the PC 90 as an ophthalmic analysis apparatus. That is, the PC 90 may also be used as an ophthalmologic analyzer. Further, the memory 72 stores various types of information related to imaging such as tomographic images (OCT data), three-dimensional tomographic images (three-dimensional OCT data), frontal fundus images, and information on imaging positions of tomographic images in the scanning line. Various operation instructions by the examiner are input to the operation input unit.
A detector (for example, a line CCD or the like) 120 for OCT imaging built in the apparatus main body 1 is connected to the PC 90 via a USB signal line via USB ports 79a and 79b. Thus, in this embodiment, the apparatus main body 1 and the PC 90 are connected to each other by the two USB signal lines 76 and 77.
In addition, the control unit 70 may detect the alignment index from the anterior segment observation image 81 imaged by the image sensor 65. The control unit 70 may detect the amount of alignment deviation of the apparatus main body 1 with respect to the eye to be examined based on the imaging signal of the imaging element 65.
Further, as shown in the anterior segment image observation screen of FIG. 4, the control unit 70 may electronically form and display a reticle LT serving as an alignment reference at a predetermined position on the screen of the display unit 75. Further, the control unit 70 may control the display of the alignment index A1 so that the relative distance from the reticle LT is changed based on the detected amount of alignment deviation.
The control unit 70 displays the anterior ocular segment observation image captured by the imaging element 65 and the fundus observation image captured by the imaging element 38 on the display unit 75 of the main body.
Further, the control unit 70 outputs the anterior ocular segment observation image and the fundus oculi observation image to the PC 90 via the HUB 71 and USB 2.0 ports 78a and 78b. The PC 90 displays the anterior ocular segment observation image and the fundus oculi observation image that are output in a streaming manner on the display unit 95 of the PC 90. The anterior ocular segment observation image and the fundus oculi observation image may be simultaneously displayed as a live image (for example, a live front image) on the display unit 95 (the anterior ocular segment observation image 81 and the FC front image 82 in FIG. 3).
On the other hand, the photographing of the color fundus image by the image sensor 35 is performed based on a trigger signal from the control unit 70. The color fundus image is also output to the control unit 70 and the PC 90 via the HUB 71 and the USB 2.0 ports 78a and 78b, and displayed on the display unit 75 or the display unit 95 of the PC 90.
Further, the detector 120 is connected to the PC 90 via the USB ports 79a and 79b. The light reception signal from the detector 120 is input to the PC 90. The PC 90 (more specifically, the processor (for example, CPU) of the PC 90) generates the tomographic image 83 by performing arithmetic processing on the light reception signal from the detector 120.
For example, in the case of Fourier domain OCT, the PC 90 processes a spectrum signal including an interference signal at each wavelength output from the detector 120. The PC 90 processes the spectrum signal to obtain internal information of the eye to be examined (for example, data of the eye to be examined (depth information) regarding the depth direction). More specifically, the spectrum signal (spectrum data) is rewritten as a function of the wavelength λ, and converted into a function I (k) that is equally spaced with respect to the wave number k (= 2π / λ). The PC 90 obtains a signal distribution in the depth (Z) region by Fourier-transforming the spectrum signal in the wave number k space.
Furthermore, the PC 90 may obtain information (for example, a tomographic image) of the eye to be examined by arranging internal information obtained at different positions by scanning the measurement light or the like. The PC 90 stores the obtained result in the memory 72. The PC 90 may display the obtained result on the display unit 95.
The apparatus main body 1 captures an image with a preset scan pattern based on a release signal from the PC 90. The PC 90 processes each image signal and outputs an image result on the display unit 95 of the PC 90.
At this time, the detector 120 outputs the detected detection signal to the PC 90. The PC 90 generates a tomographic image from the output from the detector 120.
The PC 90 transfers the generated tomographic image to the apparatus main body 1 via the USB 2.0 ports 78 b and 78 a and the HUB 71. The control unit 70 displays the transferred tomographic image 83 on the display unit 75 (see, for example, the tomographic image 83). The OCT front image may be generated by the PC 90 based on the output signal from the detector 120, and the OCT front image 84 may be displayed on the display unit 75 or the display unit 95.
In this embodiment, the examiner can perform each setting or alignment of OCT imaging settings, alignment, optimization, and the like while looking at the display unit 75 disposed in the apparatus main body 1 (details will be described later). ). Accordingly, as shown in FIG. 1B, the examiner can save the trouble of alternately checking the display unit 75 of the apparatus main body unit 1 and the display unit 95 on the PC 90 side that are arranged at different positions. Further, when taking an image by opening the subject's eyelid, the examiner may perform the opening operation more easily while checking the display unit 75 than checking the display unit 95 of the PC 90. .
Furthermore, since the tomographic image 83, the OCT front image 84, the FC front image 82, the anterior ocular segment observation image 81, and the like are displayed on both the display unit 75 and the display unit 95 of the PC 90, the examiner can It is possible to select whether to operate using the unit 1 or to operate using the PC 90 according to preference. In addition, since various captured images are displayed on both the display unit 75 and the display unit 95 of the PC 90, the number of screens on which the image can be observed is increased, and it becomes easy for a plurality of people to check the image.
In the case where measurement is performed separately for an examiner who observes an image with the display unit 95 of the PC 90 and an examiner who performs imaging with the apparatus main body unit 1, the examiner who performs imaging takes the tomography imaged with the display unit 75. If the image 83 is confirmed and shooting is not successful, shooting can be performed again. For this reason, the examiner observing the display unit 95 is less likely to tell the examiner who performs imaging to restart measurement.
As described above, by displaying the tomographic image 83 on both the display section 75 of the apparatus main body 1 and the display section 95 of the PC 90, the apparatus main body 1 can be adapted to an imaging method that suits the examiner's preference. .
The same applies to the above-described color fundus photography. The result of color fundus photography is not only input to the PC 90, but also image information such as the preview result is transferred to the apparatus main body via the USB 2.0 ports 78b and 78a and the HUB 71, and displayed on the apparatus main body 1 A color fundus image may be displayed on the portion 75. Thus, the examiner can save the trouble of alternately checking the apparatus main body 1 and the PC 90 in order to see the color fundus image. Further, when operating the apparatus main body 1 while viewing a color fundus photographed image, it is not necessary to look into the display unit 95 on the computer side, and it is only necessary to check the display unit 75, thereby reducing the burden on the examiner.
<Observation screen displaying OCT front image and FC front image>
An example of the control operation in the apparatus having the above configuration will be described. The control unit 70, for example, an anterior ocular segment observation image from the image sensor 65, a fundus oculi observation image (hereinafter referred to as an FC front image) from the image sensor 38, an OCT tomographic image (hereinafter referred to as a tomographic image) from the PC 90, and an OCT front surface. Images may be combined and displayed on the screen of the display unit 75 as an observation screen. As shown in FIG. 3, a live anterior ocular segment observation image 81, a live FC front image 82, and a live tomographic image 83 (hereinafter also referred to as a live tomographic image) may be simultaneously displayed on the observation screen.
FIG. 3 is a diagram illustrating an example of an observation screen according to the present embodiment. The control unit 70 includes a first display area 300 in which displays related to photographing with the interference optical system 200 are integrated, and a second display area 400 in which displays related to photographing with the fundus camera optical system 100 are integrated. And are displayed on the display unit 75. In this embodiment, the first display area 300 and the second display area 400 are formed in parallel on the left and right, but of course, the present invention is not limited to this. For example, the first display area 300 and the second display area 400 may be arranged in parallel vertically. In the following description, an observation screen on the display unit 75 is illustrated, but a similar observation screen may be displayed on the display unit 95 by display control of the PC 90.
The first display area 300 includes an OCT front display area (hereinafter, display area 310) 310, a scanning position setting display (hereinafter, setting display) 320, an imaging condition display (hereinafter, condition display) 330, and a tomographic image. A display area (hereinafter referred to as display area) 340 and an optical path difference adjustment display 350 are formed.
In the display area 310, an OCT front image 84 and a scan line (scan line) SL are displayed. The OCT front image (may be abbreviated as front image 85) 84 is preferably a live image. The control unit 70 updates the front image 84 displayed in the display area 310 every time a new OCT front image is acquired. When displaying the OCT front image as a live image, the control unit 70 may continuously display the front image 84 in real time, or the front image every predetermined time (for example, 0.5 seconds). May be updated.
The scanning line SL is a display for electronically indicating the scanning position (measurement position) on the OCT front image 84. The control unit 70 causes the scanning line SL to be superimposed and displayed on the OCT front image 84. Note that the display pattern of the scanning line SL corresponds to the scanning pattern by the scanning unit 108. For example, when the line scan is set, the scan line SL is displayed in a line shape. When the cross scan is set, the scan line SL is displayed in a cross shape. When the map scan (raster scan) is set, the scan line is displayed on a rectangle. Note that the relationship between the display position of the scanning line SL and the scanning position by the scanning unit 108 is set in advance.
The setting display 320 is a display for the examiner to set the OCT scanning position. For example, the control unit 70 controls the scanning unit 108 based on an operation signal input via the setting display 320, and changes the scanning position on the fundus oculi Ef. Further, the control unit 70 changes the display position of the scanning line SL in conjunction with the change of the scanning position by the scanning unit 108.
The setting display 320 of the present embodiment includes a graphic for changing the scanning position in each of the upper, lower, left and right directions and a graphic for changing the scanning position in each direction of the rotation direction. Note that the control unit 70 may change the scanning position through a direct operation (for example, drag scanning) on the scanning line SL.
The condition display 330 is a display area for indicating each imaging condition of the interference optical system 200. As the condition display 330, for example, an imaging mode, a scanning width, a scanning angle, a scanning density, the number of additions, an imaging sensitivity, and the like are displayed. As the imaging mode, for example, a combination of an imaging region and a scanning pattern can be selected, and the selected imaging mode is displayed. FIG. 3 shows a case where a mode in which a macular portion is set as the imaging region and a line scan is set as the scanning pattern is set as the imaging mode. In addition, when each condition display displayed on the condition display 330 is operated, the shooting conditions can be changed. For example, when the condition display corresponding to the scanning width is operated, the scanning width can be changed.
In the display area 340, an OCT tomographic image (hereinafter referred to as tomographic image) 83 and an image evaluation display 345 are displayed.
The tomographic image 83 is preferably a live image. The control unit 70 updates the tomographic image 83 displayed in the display area 340 every time a new tomographic image is acquired. When displaying the tomographic image as a live image, the control unit 70 may display the tomographic image 83 continuously in real time, or the tomographic image may be displayed every predetermined time (for example, 0.5 seconds). You may make it update.
Here, when the scanning line is changed as described above, the control unit 70 can display the tomographic image 83 corresponding to the changed scanning position. Note that when a scan pattern including a plurality of scan lines is set as the scan pattern, the control unit 70 may display a tomographic image corresponding to each scan line.
The image evaluation display 345 is a display for evaluating whether or not the image quality of the tomographic image is good. In this embodiment, 10-level evaluation is performed using a bar graph. The PC 90 analyzes the acquired tomographic image and evaluates the image based on the analysis result. The control unit 70 displays the analysis result transmitted from the PC 90 as an image evaluation display 345. In addition, when the result of the image evaluation display 345 is bad, it is possible to increase the imaging sensitivity or to adjust the position of the imaging unit 3 with respect to the patient's eye using the anterior ocular segment observation image 81.
The optical path difference adjustment display 350 is a display area for adjusting the optical path length difference between the measurement light and the reference light. When the automatic adjustment display (AUTO Z) is operated, the control unit 70 controls the drive unit 150 to automatically adjust the optical path length difference so that a tomographic image of the fundus is acquired.
When the manual adjustment display (arrow) is operated, the control unit 70 controls the drive unit 150 according to the operation direction and the operation amount (operation time) to adjust the optical path length difference. Thus, the optical path length difference is finely adjusted by the manual operation of the examiner.
Next, the second display area 400 will be described. In the second display area 400, an FC front display area 410, an anterior ocular segment image display area 420, an imaging condition display (hereinafter referred to as condition display) 430, and a pupil diameter determination display 440 are formed.
In the display area 410, an FC front image 82, focus index images S1 and S2, and optical alignment index images W1 and W2 (optical working dots) are displayed. The FC front image (may be abbreviated as front image 82) 82 is preferably a live image. The control unit 70 updates the FC front image 82 displayed in the display area 410 every time a new FC front image is acquired. When displaying the FC front image 82 as a live image, the control unit 70 may continuously display the FC front image 82 in real time, or at regular intervals (for example, 0.5 seconds). The front image 82 may be updated.
When the alignment with respect to the eye to be examined is properly performed to some extent, the optical alignment indices W1 and W2 by the corneal reflection light formed by the light source 55 appear on the front image 82. Further, the observation light is shielded by the lever 45 inserted in the optical path of the illumination optical system 10, whereby a light shielding region 415 is formed on the image sensor 38, and projected onto the fundus at the tip (on the optical axis) of the light shielding region 415. The optical focus index images S1 and S2 thus formed are formed.
In the anterior segment image display area 420, an anterior segment observation image 81 is displayed. The anterior ocular segment observation image 81 is preferably a live image. The control unit 70 updates the anterior ocular segment observation image 81 displayed in the display area 420 every time a new anterior ocular segment observation image is acquired. When displaying the anterior ocular segment observation image as a live image, the control unit 70 may continuously display the anterior ocular segment observation image 81 in real time, or may display a predetermined time (for example, 0.5 seconds). ) The front image may be updated every time. In this embodiment, the anterior segment image display area 420 is displayed in a display area smaller than the FC front display area 410. Of course, it is not limited to this.
The condition display 430 is a display area for indicating each photographing condition of the fundus camera optical system 100. As the condition display 430, for example, the photographing light amount of the photographing light source 14, the diopter correction amount by the focusing lens 32, the presence / absence of selection of a small pupil photographing mode, the presence / absence of selection of a low light amount photographing mode, and the like can be considered. In addition, when each icon (or condition display) displayed on the condition display 430 is operated, the shooting condition can be changed. For example, when the icon corresponding to the photographic light quantity is operated, the photographic light quantity can be changed.
The pupil diameter determination display 440 is a display for displaying whether or not the pupil diameter of the subject's eye satisfies the required pupil diameter. Whether or not the required pupil diameter is satisfied is determined by image processing whether or not the pupil diameter in the anterior ocular segment observation image satisfies a predetermined size. The control unit 70 changes the display state of the pupil diameter determination display 440 based on the determination result (details will be described later).
The display position of the fixation target may be adjusted in any one of the display area 340 and the display area 410. In this case, a mark indicating the fixation target presentation position is displayed on one of the front images, and the presentation position is changed by moving the mark on the monitor 75.
Note that, when the OCT front image 84 is not acquired, the control unit 70 may display an image obtained by cutting out the corresponding part of the FC front image 82 in the display area 310.
<Shooting procedure>
The operation of the apparatus using the above apparatus will be described below. The examiner causes the face support unit 5 to support the face of the subject. Then, the examiner instructs the subject to watch the fixation target (not shown). At the initial stage, the dichroic mirror 24 is inserted in the optical path of the photographing optical system 30, and an anterior segment image captured by the image sensor 65 is displayed on the display unit 75.
For example, the examiner operates the joystick 74a as the vertical / left / right alignment adjustment, and moves the photographing unit 3 left / right / up / down so that the anterior segment image appears on the display unit 75. When the anterior segment image appears on the display unit 75, eight index images (first alignment index images) Ma to Mh appear as shown in FIG. In this case, the imaging range by the imaging element 65 is preferably a range that includes the pupil, iris, and eyelid of the anterior eye portion when the alignment is completed.
<Alignment detection and automatic alignment in XYZ directions>
When the alignment index images Ma to Mh are detected by the two-dimensional image sensor 65, the control unit 70 starts automatic alignment control. The control unit 70 detects the alignment deviation amount Δd of the imaging unit 3 with respect to the eye to be examined based on the imaging signal output from the two-dimensional imaging element 65. More specifically, the XY coordinates of the center of the ring shape formed by the index images Ma to Mh projected in a ring shape are detected as the approximate corneal center, and the alignment reference in the XY directions set in advance on the image sensor 65 is used. A deviation amount Δd between the position O1 (for example, the intersection of the imaging surface of the imaging element 65 and the imaging optical axis L1) and the corneal center coordinates is obtained (see FIG. 7). Note that the center of the pupil may be detected by image processing, and the misalignment may be detected based on the amount of deviation between the coordinate position and the reference position O1.
Then, the control unit 70 operates automatic alignment by drive control of the XYZ drive unit 6 so that the deviation amount Δd falls within the allowable range A for completion of alignment. Depending on whether the deviation amount Δd is within the allowable range A for completion of alignment and the time continues for a certain time (for example, 10 frames for image processing or 0.3 seconds) (whether the alignment condition A is satisfied). , Whether the alignment in the XY directions is appropriate or not is determined.
Further, the control unit 70 obtains the alignment deviation amount in the Z direction by comparing the interval between the index images Ma and Me at infinity detected as described above and the interval between the index images Mh and Mf at finite distance. . In this case, when the photographing unit 3 is shifted in the working distance direction, the control unit 70 changes the image interval between the index images Mh and Mf while the interval between the infinite indexes Ma and Me hardly changes. The amount of alignment deviation in the working distance direction with respect to the eye to be examined is obtained using the characteristic of performing (see Japanese Patent Laid-Open No. 6-46999 for details).
Further, the control unit 70 also obtains a deviation amount with respect to the alignment reference position in the Z direction in the Z direction, and the XYZ driving unit 6 so that the deviation amount falls within an alignment allowable range in which the alignment is completed. The automatic alignment by the drive control is activated. Whether or not the alignment in the Z direction is appropriate is determined based on whether or not the amount of deviation in the Z direction is within an allowable range for completion of alignment for a certain period of time (whether the alignment condition is satisfied).
When the alignment operation in the XYZ directions satisfies the alignment completion condition by the alignment operation described above, the control unit 70 determines that the alignment in the XYZ directions is matched, and proceeds to the next step.
Here, when the alignment deviation amount Δd in the XYZ directions falls within the allowable range A1, the drive of the drive unit 6 is stopped and an alignment completion signal is output. Even after the alignment is completed, the control unit 70 detects the displacement amount Δd as needed, and resumes automatic alignment when the displacement amount Δd exceeds the allowable range A1. That is, the control unit 70 performs control (tracking) for tracking the imaging unit 3 with respect to the subject's eye so that the deviation amount Δd satisfies the allowable range A1.
<Determination of pupil diameter>
After the alignment is completed, the control unit 70 starts determining whether or not the pupil state of the eye to be examined is appropriate. In this case, whether or not the pupil diameter is appropriate is determined based on whether or not the pupil edge detected from the anterior segment image by the image sensor 65 is out of a predetermined pupil determination area. The size of the pupil determination area is set as a diameter (for example, a diameter of 4 mm) through which the fundus illumination light beam can pass with the image center (imaging optical axis center) as a reference. For simplicity, four pupil edges detected in the horizontal direction and the vertical direction with respect to the center of the image are used. If the pupil edge point is outside the pupil determination area, the illumination light quantity at the time of photographing is sufficiently secured (for details, refer to Japanese Patent Application Laid-Open No. 2005-160549 by the present applicant). The pupil diameter suitability determination is continued until imaging is executed, and the determination result is displayed on the display unit 75.
<Focus state detection / Auto focus>
When the alignment using the image sensor 65 is completed, the control unit 70 performs autofocus on the fundus of the eye to be examined. FIG. 5 is an example of a fundus image captured by the image sensor 38, and focus index images S1 and S2 by the focus target projection optical system 40 are projected at the center of the fundus image. Here, the focus index images S1 and S2 are separated when they are not in focus, and are projected in agreement when they are in focus. The control unit 70 detects the index images S1 and S2 by image processing and obtains separation information thereof. Then, the control unit 70 controls the driving of the moving mechanism 49 based on the separation information of the index images S1 and S2, and moves the lens 32 so that the fundus is in focus.
When the alignment completion signal is output, the control unit 70 issues a trigger signal for starting the optimization control, and starts the optimization control operation. The control unit 70 performs optimization so that the fundus site desired by the examiner can be observed with high sensitivity and high resolution. In the present embodiment, the optimization control is control of optical path length adjustment, focus adjustment, and polarization state adjustment (polarizer adjustment). In the optimization control, it is only necessary to satisfy a certain permissible condition for the fundus, and it is not always necessary to adjust to the most appropriate state.
In the optimization control, the control unit 70 sets the positions of the reference mirror 131 and the focusing lens 124 to the initial positions as initialization control. After the initialization is completed, the control unit 70 moves the reference mirror 131 in one direction from the set initial position in a predetermined step to perform the first optical path length adjustment (first automatic optical path length adjustment). In parallel with the first optical path length adjustment, the control unit 70 focuses information on the fundus of the eye to be examined (for example, movement of the lens 32) based on the focus result of the fundus camera optical system with respect to the fundus of the eye to be examined. Amount). When the in-focus position information is acquired, the control unit 70 moves the focussing lens 124 to the in-focus position and performs autofocus adjustment (focus adjustment). Note that the in-focus position may be a position where the contrast of the tomographic image acceptable as the observation image can be acquired, and is not necessarily the optimum position in the focus state.
Then, after the focus adjustment is completed, the control unit 70 moves the reference mirror 131 again in the optical axis direction, and performs the second optical path length adjustment for readjustment of the optical path length (fine adjustment of the optical path length). After completing the second optical path length adjustment, the control unit 70 drives the polarizer 133 for adjusting the polarization state of the reference light to adjust the polarization state of the measurement light (for details, refer to Japanese Patent Application No. 2012-56292).
As described above, when the optimization control is completed, the fundus site desired by the examiner can be observed with high sensitivity and high resolution. Then, the control unit 70 controls driving of the scanning unit 108 and scans the measurement light on the fundus.
A detection signal (spectrum data) detected by the detector 120 is transmitted to the PC 90 via the USB ports 79a and 79b (see FIG. 6). The PC 90 receives the detection signal, and generates a tomographic image 83 by processing the detection signal.
When the PC 90 generates the tomographic image 83, the tomographic image 83 is transmitted to the control unit 70 of the apparatus main body 1 via the USB 2.0 ports 78 b and 78 a and the HUB 71. The control unit 70 receives the tomographic image 83 from the PC 90 via the USB 2.0 ports 78 b and 78 a and the HUB 71 and displays the tomographic image 83 on the display unit 75. As shown in FIG. 3, the control unit 70 displays the anterior ocular segment observation image 81, the FC front image 82, and the tomographic image 83 on the display unit 75.
The examiner confirms the tomographic image 83 updated in real time, and adjusts the alignment in the Z direction. For example, the alignment may be adjusted so that the tomographic image 83 fits within the display frame.
Of course, the PC 90 may display the generated tomographic image 83 on the display unit 90. The PC 90 may display the generated tomographic image 83 on the display unit 95 in real time. Further, the PC 90 may display the anterior eye portion observation image 81 and the FC front image 82 on the display unit 95 in real time in addition to the tomographic image 83.
In the case where the focus adjustment of the image is manually performed, the examiner has described that the adjustment is performed by operating the adjustment knob 74d or the like. However, the present invention is not limited to this. For example, the examiner may adjust the image by performing a touch operation on a display unit (for example, the display unit 75) having a touch panel function.
When the alignment and the image quality adjustment are completed, the control unit 70 controls driving of the scanning unit 108, scans the measurement light on the fundus in a predetermined direction, and outputs a predetermined value from an output signal output from the detector 120 during the scanning. A light reception signal corresponding to the scanning region is acquired to form a tomographic image.
FIG. 3 is a diagram illustrating an example of a display screen displayed on the display unit 75. The control unit 70 displays an anterior ocular segment observation image 81, an FC front image 82, a tomographic image 83, and a scanning line 85 acquired by the anterior ocular segment observation optical system 60 on the display unit 75. The scanning line 85 is an index representing the measurement position (acquisition position) of the tomographic image on the FC front image 82. The scanning line 85 is electrically displayed on the FC front image 82 on the display unit 75.
In this embodiment, the imaging condition can be set when the examiner performs a touch operation or a drag operation on the display unit 75. The examiner can specify an arbitrary position on the display unit 75 by a touch operation.
When the tomographic image and the OCT front image 84 are displayed on the display unit 75, the examiner sets the position of the tomographic image that the examiner wants to photograph from the OCT front image 84 on the display unit 75 observed in real time. Here, the examiner moves the scanning line SL with respect to the FC front image 82 and sets the scanning position (for example, drag operation of the scanning line SL, operation of the setting display 320). If the line is set to be in the X direction, a tomographic image on the XZ plane is taken, and if the scanning line 85 is set to be in the Y direction, a tomographic image on the YZ plane is taken. It has become. Further, the scanning line 85 may be set to an arbitrary shape (for example, an oblique direction or a circle).
In the present embodiment, the operation of the touch panel type display unit 75 provided in the apparatus main body 1 has been mainly described, but the present invention is not limited to this. The same operation as that of the display unit 75 may be performed by operating a joystick 74a or various operation buttons provided in the operation unit 74 of the apparatus body 1. Also in this case, for example, the operation signal from the operation unit 74 may be transmitted to the PC via the control unit 70, and the PC may transmit a control signal corresponding to the operation signal to the control unit 70.
When the scan line SL is moved with respect to the FC front image 82 by the examiner, the control unit 70 sets the scan position at any time and acquires a tomographic image at the corresponding scan position. The acquired tomographic image is displayed on the display screen of the display unit 75 as needed. Further, the control unit 70 changes the scanning position of the measurement light based on the operation signal output from the display unit 75, and displays the scanning line SL at the display position corresponding to the changed scanning position. Since the relationship between the display position of the scanning line SL (coordinate position on the display unit) and the scanning position of the measurement light by the scanning unit 108 is determined in advance, the control unit 70 sets the display position of the scanning line SL set. The two galvanometer mirrors of the scanning unit 108 are appropriately driven and controlled so that the measurement light is scanned with respect to the scanning range corresponding to.
According to the above configuration, since the OCT front image 84 and the FC front image 82 are simultaneously displayed in different display areas, the examiner uses the OCT front image 84 to adjust the scanning position, Fixation lamp position adjustment, focus adjustment, polarization control, and the like can be performed, and alignment adjustment, focus adjustment, and the like can be performed using the FC front image 82.
In this case, since the OCT front image 84 is a front image obtained by optical scanning, it is possible to confirm more detailed information than the FC front image (for example, it is easy to confirm the running state of the blood vessels and abnormal sites). Therefore, the scan position can be adjusted appropriately.
On the other hand, flare due to reflection from the eye to be examined may occur in the FC front image 82. The examiner can photograph a fundus front image with reduced flare by moving the imaging unit 3 with respect to the subject's eye so that the flare is reduced. Alternatively, the examiner can perform alignment adjustment using the optical alignment indices W1 and W2. Alternatively, the examiner can perform focus adjustment using the focus indexes S1 and S2.
When only one of the OCT front image 84 and the FC front image 82 is displayed, it is difficult to perform adjustment on the interference optical system 200 side and adjustment on the FC optical system 100 side. Further, there is a possibility that the optical alignment indexes W1 and W2 and the focus indexes S1 and S2 are hidden by the scanning line. As a result, it is difficult to properly adjust both. On the other hand, in this embodiment, since both the OCT front image 84 and the FC front image 82 are displayed, both adjustments can be suitably performed.
As described above, when the photographing start switch 74c is operated by the examiner after the photographing condition setting is completed, the control unit 70 starts photographing an image. FIG. 8 is a flowchart for explaining the photographing operation. Hereinafter, the photographing operation will be described with reference to FIG.
First, the control unit 70 acquires the FC front image 82 illuminated by the observation light source 11 and captured by the image sensor 38 as a still image (first FC front image) (S11). The acquired first FC front image (hereinafter referred to as a first infrared fundus image) is received by the PC 90 via the HUB 71 and the USB 2.0 ports 78a and 78b, and then stored in the memory 72.
Next, the control unit 70 acquires a tomographic image (S12). The control unit 70 acquires a tomographic image by B scan based on the set scanning position. Based on the display position of the scanning line SL set on the OCT front image 84, the control unit 70 drives the scanning unit 108 so that a tomographic image of the fundus corresponding to the position of the scanning line SL is obtained. Scan light.
The PC 90 generates a still image of the tomographic image 83 based on the detection signal from the detector 120. The PC 90 stores the tomographic image 83 in the memory 72.
When the tomographic image is acquired, the control unit 70 acquires again the FC front image 82 illuminated by the observation light source 11 and captured by the image sensor 38 as a still image (second FC front image) (S13). . The acquired second FC front image (hereinafter, second infrared fundus image) is received by the PC 90 via the HUB 71 and the USB 2.0 ports 78a and 78b, and then stored in the memory 72.
Next, the control unit 70 proceeds to a step of acquiring a color fundus image by the fundus camera optical system 100. The controller 70 drives the insertion / removal mechanism 66 to cause the dichroic mirror 24 to leave the optical path and cause the imaging light source 14 to emit light.
When the imaging light source 14 emits light, the fundus of the eye to be examined is irradiated with visible light. Reflected light from the fundus passes through the objective lens 25, the aperture of the perforated mirror 22, the photographing aperture 31, the focusing lens 32, the imaging lens 33, and the dichroic mirror 37 and forms an image on the two-dimensional light receiving element 35. The color fundus image captured by the two-dimensional light receiving element 35 is received by the PC 90 via the HUB 71 and the USB 2.0 ports 78a and 78b, and then stored in the memory 72.
In the present embodiment, the configuration in which the second infrared fundus image and the color fundus image are automatically acquired after the tomographic image acquisition is described as an example, but the present invention is not limited to this. For example, after the tomographic image is acquired, before the acquisition of the second infrared fundus image and the color fundus image, fine adjustment of the alignment and focus by the examiner may be performed. For example, after acquiring the tomographic image, the control unit 70 causes the display unit 75 to display an adjustment screen for performing fine adjustment of alignment and focus. While observing the FC front image 82 displayed on the display unit 75, the examiner performs fine adjustment of alignment and focus so that a color fundus image can be captured in a desired state. Then, when the examiner inputs the photographing start switch 74c, photographing of the second infrared fundus image and the color fundus image may be executed. In this case, when there is an input of the imaging start switch 74c by the examiner, the control unit 70 first acquires the second infrared fundus image. After acquiring the second infrared fundus image, the control unit 70 acquires a color fundus image.
<Image analysis processing>
When the acquisition of the tomographic image and the acquisition of the color fundus image is completed in this way, the control unit 70 performs the matching process between the tomographic image and the color fundus image, thereby associating the positional relationship between the tomographic image and the color fundus image. .
Hereinafter, image analysis processing for associating the positional relationship between the tomographic image and the color fundus image will be described. In the present embodiment, the control unit 70 acquires a first infrared fundus image (first front image) and a color fundus image (second image) acquired when acquiring a tomographic image (first image). At this time, the acquired second infrared fundus image (second front image) is used to associate the positional relationship between the tomographic image and the color fundus image.
For example, the control unit 70 detects the displacement amount of the first infrared fundus image and the second infrared fundus image stored in the memory 72, and based on the displacement amount, the tomographic image 83, the color fundus image, The positional relationship is made to correspond.
For example, various image processing methods (a method using various correlation functions, a method using Fourier transform, a method based on feature point matching) can be used as a method for detecting the amount of positional deviation between two images. It is.
For example, a predetermined reference image (for example, a first infrared fundus image) or a target image (second infrared fundus image) is displaced by one pixel at a time, and the reference image and the target image are compared. It is conceivable to detect the amount of misalignment between the two data (when the correlation is highest). Further, a method of extracting a common feature point from a predetermined reference image and target image and detecting a positional shift of the extracted feature point is conceivable.
Here, if there is no position shift between the two images, only the cosine wave is added, and a peak appears at the origin position (0, 0). Further, when there is a positional deviation, a peak appears at a position corresponding to the positional deviation. Therefore, the amount of displacement between the two images can be obtained by obtaining the peak detection position. According to this method, it is possible to detect the amount of displacement between the first infrared fundus image and the second infrared fundus image with high accuracy and in a short time.
In the present embodiment, the control unit 70 also uses a method of extracting common feature points from the first infrared fundus image and the second infrared fundus image and detecting the amount of positional deviation of the extracted feature points.
When detecting the positional deviation amount, the control unit 70 associates the positional relationship between the tomographic image 83 and the color fundus image based on the positional deviation amount.
Here, since the tomographic image 83 and the first infrared fundus image are acquired substantially simultaneously, both data can be associated with each other in a pixel-to-pixel relationship. In addition, since the color fundus image and the second infrared fundus image are acquired substantially simultaneously (or completely simultaneously), both data can be associated with each other in a pixel-to-pixel relationship. That is, in the present embodiment, the first infrared fundus image is acquired and the tomographic image 83 is acquired quickly. Further, the second infrared fundus image is acquired, and the color fundus image is acquired quickly. For this reason, the positional relationship between the first infrared fundus image and the second infrared fundus image and the other images (tomographic image and color fundus image) is hardly displaced. For this reason, since it is not necessary to associate the positional relationship between the first infrared fundus image and the second infrared fundus image with another image, the first infrared fundus image and the second infrared fundus image are front images. The displacement amount can be applied as the displacement amount between the tomographic image 83 and the color fundus image. For this reason, it is not necessary to perform a plurality of associations between the images, and the tomographic image 83 and the color fundus image can be associated with each other easily and accurately.
For example, the control unit 70 corrects the display position of the scanning line SL displayed on the color fundus image based on the positional deviation amount so that the correspondence relationship between the tomographic image 83 and the color fundus image matches. As described above, since the tomographic image 83 and the first infrared fundus image are acquired substantially simultaneously, the tomographic image 83 and the first infrared fundus image are associated with each other. That is, on the OCT front image 84, based on the display position of the scanning line SL when the acquisition position of the tomographic image 83 is set, the acquisition position of the tomographic image 83 on the first infrared fundus image (the tomographic image was captured). Site) has been identified. Similarly, the color fundus image and the second infrared fundus image are associated with each other. The control unit 70 specifies the acquisition position of the tomographic image 83 on the color fundus image based on the displacement amount obtained as described above. Based on the acquired acquisition position information of the tomographic image 83, the control unit 70 electrically displays a scanning line SL indicating the imaging position at which the tomographic image is acquired on the color fundus image. In this way, the control unit 70 corrects the display position of the scanning line SL displayed on the color fundus image based on the positional deviation amount. Accordingly, the control unit 70 associates the positional relationship between the tomographic image 83 and the color fundus image based on the positional deviation amount.
When the correspondence between the positional relationship between the tomographic image and the color fundus image is completed, the control unit 70 transmits each image and the associated result to the PC 90 via the HUB 71 and the USB 2.0 ports 78a and 78b. . The PC 90 displays each image and the associated result on the display unit 95. Of course, the PC 90 may display each image and the associated result on the display unit 75. The control unit 70 may display each image and the associated result on the display unit 75.
As described above, when the tomographic image and the color fundus image are associated with each other, the tomographic image and the color fundus image are not associated with each other, and a front image having a common imaging method is separately obtained. Each fundus image is acquired at the time of acquisition, and the tomographic image and the color fundus image are associated with each other based on the amount of positional deviation between the front images having the same imaging method. Thereby, it is possible to accurately associate different images (tomographic images and color fundus images).
Further, as described above, by associating the tomographic image with the color fundus image, the examiner confirms the acquisition position on the fundus corresponding to the acquired desired fundus tomographic image on the color fundus image. can do. This makes it possible for the examiner to accurately grasp the correspondence between the color fundus image and the tomographic image, which is excellent in resolution and contrast and suitable for finding a lesion from the entire fundus, and is useful for the subject. Can be performed.
Further, as described above, the control unit 70 performs the first front image (for example, the first infrared fundus image), the first image (for example, the tomographic image 83), and the second front image (for example, the second infrared image). By acquiring a series of images in the order of a fundus image) and a second image (for example, a color fundus image), the fundus of the eye to be examined can be easily captured. In other words, when the color fundus image is captured first, the eye to be examined is reduced in pupil size, making it difficult for the measurement light for tomographic image photography to enter the eye and obtaining a tomographic image becomes difficult. However, by performing a series of image acquisition in the order as described above, it is possible to easily acquire a tomographic image and a color fundus image.
In addition, by acquiring the front image used for association between the acquisition of the tomographic image and the acquisition of the color fundus image, even when it takes time to acquire the tomographic image, The tomographic image and the color fundus image can be easily and accurately associated with each other using the first infrared fundus image and the second infrared fundus image at the time of obtaining the color fundus image.
In this embodiment, the tomographic image 83 is acquired together with the first infrared fundus image, and the color fundus image is acquired together with the second infrared fundus image, whereby the first infrared fundus image and the second infrared fundus image are acquired. Although it is configured that there is no need to re-associate the positional relationship between the fundus image and another image, the present invention is not limited to this. It is good also as a structure which matches the positional relationship of a 1st infrared fundus image and a 2nd infrared fundus image, and another image. For example, when associating the tomographic image 83 and the first infrared fundus image, the control unit 70 acquires a still image of the OCT front image 84 at the time of acquiring the tomographic image 83 together with the tomographic image. The control unit 70 detects the positional deviation amount between the still image OCT front image and the first infrared fundus image, and based on the positional deviation amount, the positional relationship between the OCT front image and the first infrared fundus image. To correspond. Thus, it can be determined which position on the first infrared fundus image the predetermined part on the OCT front image corresponds to. That is, the acquisition position of the tomographic image on the first infrared fundus image can be set. Further, for example, when the color fundus image and the second infrared fundus image are associated with each other, the control unit 70 detects the positional deviation amount between the color fundus image and the second infrared fundus image, and based on the positional deviation amount, The positional relationship between the image and the first infrared fundus image is made to correspond.
In the present embodiment, the tomographic image acquired by line scanning has been described as an example of the tomographic image associated with the color fundus image, but the tomographic image is not limited to this. For example, the tomographic image may be a three-dimensional tomographic image. In such a case, the three-dimensional tomographic image and the color fundus image are associated based on the amount of positional deviation between the infrared fundus images. Then, for example, when the examiner selects a desired position on the color fundus image after completion of imaging, the control unit 70 extracts a tomographic image corresponding to the selected position from the three-dimensional tomographic image and displays it. You may display on the part 75. FIG.
In the present embodiment, the technique of the present disclosure has been described by taking the association between the tomographic image 83 and the color fundus image as an example, but the present disclosure is not limited thereto. The technology of the present disclosure can be applied when the first image and the second image are associated with each other. For example, the technology of the present disclosure can also be applied to a configuration in which an analysis map acquired by analyzing a tomographic image is associated with a color fundus image. For example, the technique of the present disclosure can be applied to a configuration in which a tomographic image and a visual field measurement result are associated with each other.
In the present embodiment, two front images of the first infrared fundus image and the second infrared fundus image are acquired and associated as images for associating the tomographic image 83 with the color fundus image. However, the present invention is not limited to this. The number of front images to be acquired may be at least two. For example, when the control unit 70 acquires a plurality of front images when acquiring the first image, the control unit 70 selects, as the front image used for the association, the one having the best shooting state from the plurality of front images. It may be. For example, a good shooting state includes a high contrast and luminance value.
In this embodiment, two front images of a first infrared fundus image and a second infrared fundus image are acquired as images for associating one tomographic image 83 with one color fundus image. Thus, the association is performed, but the present invention is not limited to this. The technique disclosed in the present invention can be applied even when a plurality of tomographic images and a plurality of color fundus images are associated with each other. In this case, for example, the control unit 70 acquires a plurality of first images and also acquires a plurality of front images. Moreover, the control part 70 acquires a some front image with the acquisition of a some 2nd image, respectively. Here, for example, when the control unit 70 selects one tomographic image from the plurality of tomographic images and associates it with the color fundus image, the front image of the selected tomographic image and the plurality of color fundus images are obtained. The amount of positional deviation between each front image and the image is calculated in order. The control unit 70 selects a color fundus image corresponding to the front image with the smallest amount of positional deviation from the calculated amount of positional deviation from the plurality of color fundus images, and associates it with the selected tomographic image. May be performed. For example, when the control unit 70 selects one tomographic image from a plurality of tomographic images and associates the tomographic image with a color fundus image, the front image of the selected tomographic image and the plurality of color fundus images are selected. Each of the front images is compared with the photographing conditions (for example, light amount, fixation position, etc.). The control unit 70 may select a color fundus image corresponding to the front image with the most similar imaging conditions from a plurality of color fundus images and associate the selected fundus image with the selected tomographic image. In the above description, the control unit 70 has been described with an example of a configuration in which one tomographic image is selected from a plurality of tomographic images and associated with a color fundus image, but the present invention is not limited thereto. Not. For example, a configuration in which one selected tomographic image is associated with a plurality of color fundus images may be configured, or a plurality of tomographic images may be associated with one selected color fundus image. By adopting such a configuration, it is possible to associate the first image and the second image with a closer correlation.
In the present embodiment, a first front image (for example, a first infrared fundus image) and a second front image (for example, a second infrared fundus image), which are also used as a reference for association between different images, are compared. By doing so, you may provide the structure which the blink of a to-be-tested eye detects. For example, the control unit 70 detects the displacement amount of the first infrared fundus image and the second infrared fundus image stored in the memory 72, and determines whether the displacement amount is larger than a predetermined threshold. It is determined whether or not blinking has occurred. In this case, for example, the control unit 70 may determine that there is a possibility that blinking has occurred when the positional deviation amount is larger than a threshold value. That is, when blinking occurs, the area common to the front images decreases, and the amount of positional deviation increases. As a result, blinking can be detected. In addition, the structure which detects the blink of a to-be-tested eye is not limited to the structure detected based on the positional offset amount of a 1st infrared fundus image and a 2nd infrared fundus image. The configuration for detecting the blink of the eye to be examined may be any configuration that performs detection based on the comparison result between the first front image and the second front image that are also used as the reference for association. For example, blink may be detected by determining whether or not the degree of similarity between the first front image and the second front image is large. In this case, for example, the control unit 70 compares the brightness values, contrasts, and the like of the first front image and the second front image, and determines whether there is a similarity by determining how much correlation there is. You may do it. Accordingly, for example, the control unit 70 determines that blinking has occurred when the similarity is low. As described above, by comparing the first front image at the time of acquiring the first image (for example, a tomographic image) and the second front image after completion of acquisition of the first image, a configuration for detecting blink of the eye to be examined. By providing, it is possible to detect whether or not blinking has occurred during the shooting of the first image. For this reason, a more suitable first image can be acquired.
In this embodiment, when detecting the amount of positional deviation, the amount of positional deviation may be detected by excluding a predetermined region. For example, the control unit 70 excludes a predetermined area in each front image on the first front image and the second front image when detecting the amount of positional deviation between the first front image and the second front image. Then, the amount of displacement is detected. That is, when the position deviation detection is performed, the control unit 70 excludes a portion that is highly likely to become an obstacle from the region for detection. For example, when the control unit 70 sets a predetermined region (for example, a split index region, a working dot region, or the like) in the first infrared fundus image and the second infrared fundus image, and detects the amount of displacement. In addition, the predetermined area is excluded from the calculation and the amount of positional deviation is detected. Further, for example, a configuration may be adopted in which a predetermined area is removed based on imaging conditions (for example, a scanning pattern, a fixation position, etc.). In this way, on the front image used for the correspondence, by removing the split index that overlaps the fundus portion, working dots, and other areas and calculating the amount of displacement, a more accurate amount of displacement can be obtained. Can be calculated. As a result, the first image and the second image can be associated with each other with high accuracy. For the predetermined area to be excluded, the obstacle area is specified in advance on the front image used for the association in which the model eye is photographed, and the coordinate position of the corresponding area is stored in the memory 72. You can set it. Of course, the predetermined area to be excluded may be configured to detect and set a faulty area from the captured front image for association.
In the present embodiment, the case where the fundus of the subject's eye is photographed has been described as an example of the ophthalmologic photographing apparatus. However, the present invention is not limited to this. The technique of the present disclosure can also be applied when imaging the anterior segment of the eye to be examined.
1 Ophthalmology photographing apparatus 70 Control unit 71 HUB
74 Operation unit 75 Display unit 76, 77 USB signal line 78a, 78b USB 2.0 port 79a, 79b USB port 90 Computer 95 Display unit
An ophthalmologic photographing apparatus for photographing a subject eye,
A first photographing optical system for photographing a first image of the eye to be examined by photographing the eye to be examined using a first imaging method;
A second photographing optical system for photographing a second image of the eye to be examined by photographing the eye to be examined using a second imaging method different from the first imaging method;
A third photographing optical system for photographing a front image of the eye to be examined by photographing the eye using a third imaging method different from the first imaging method and the second imaging method; With
When acquiring the first image with the first imaging optical system, acquiring the first front image with the third imaging optical system and acquiring the second image with the second imaging optical system. The second photographic optical system acquires a second front image that is a front image different from the first front image, stores the first front image in the memory in association with the first image, and Control means for storing two front images in the memory in association with the second image ;
A displacement amount between the first front image and the second front image is detected for the first front image, the second front image, the first image, and the second image stored in the memory. Image processing means for associating the first image with the second image based on the positional deviation amount;
The third imaging optical system is configured to capture an infrared illumination optical system for illuminating the fundus of the subject's eye with infrared light, and a front image of the fundus of the subject's eye illuminated with the infrared light. an infrared imaging optical system, has, as the first front image and the second front image, it photographing optical system der for photographing the infrared fundus image of the eye to be examined,
The first imaging optical system has an OCT optical system for obtaining a tomographic image of the fundus of the subject's eye using an optical interference technique, and takes a tomographic image of the fundus of the subject's eye as the first image. Photographing optical system for
The second photographing optical system includes a visible illumination optical system for illuminating the fundus of the subject's eye with visible light, and a visible photographing optical for photographing a front image of the fundus of the subject's eye illuminated with the visible light. An ophthalmologic photographing apparatus for photographing a color fundus image of the eye to be examined as the second image .
The ophthalmologic photographing apparatus according to claim 2 ,
The control means acquires the second front image by the third photographing optical system after the first front image and the first image are obtained by the first photographing optical system and the third photographing optical system. An ophthalmologic photographing apparatus that performs control for obtaining the second image by the second photographing optical system after obtaining the second front image .
An ophthalmologic imaging method for imaging a subject eye,
A first image obtaining step of obtaining a first image of the eye to be examined by photographing the eye to be examined using a first imaging method , and storing the first image in a memory ;
A second image acquisition step of acquiring a second image of the eye to be examined by photographing the eye to be examined using a second imaging method different from the first imaging method , and storing the second image in a memory ;
A third image acquisition step for acquiring a front image of the eye to be inspected by imaging the eye to be inspected using a third imaging method different from the first imaging method and the second imaging method; Te, when obtaining the first image to obtain a first front image, when obtaining the second front image, obtains a second front image of a different front image from the first front image A third image acquisition step of storing the first front image in the memory in association with the first image and storing the second front image in the memory in association with the second image ;
A displacement amount between the first front image and the second front image is detected for the first front image, the second front image, the first image, and the second image stored in the memory. An image processing step of associating the first image with the second image based on the amount of displacement;
An ophthalmologic photographing method comprising:
An ophthalmologic imaging program that is executed in a control device that controls the operation of the ophthalmologic imaging apparatus for imaging the eye to be examined,
By being executed by the processor of the control device ,
Ophthalmic imaging program characterized by executing the control device.
JP2014073656A 2014-03-31 2014-03-31 Ophthalmic photographing apparatus, ophthalmic photographing method, and ophthalmic photographing program Active JP6349878B2 (en)
JP2014073656A JP6349878B2 (en) 2014-03-31 2014-03-31 Ophthalmic photographing apparatus, ophthalmic photographing method, and ophthalmic photographing program
US14/671,636 US9687143B2 (en) 2014-03-31 2015-03-27 Ophthalmic photography device, ophthalmic photography method, and ophthalmic photography program
JP2015195808A JP2015195808A (en) 2015-11-09
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JP2014073656A Active JP6349878B2 (en) 2014-03-31 2014-03-31 Ophthalmic photographing apparatus, ophthalmic photographing method, and ophthalmic photographing program
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JP2017169602A (en) * 2016-03-18 2017-09-28 株式会社トプコン Ophthalmologic apparatus
JP5941761B2 (en) * 2012-06-11 2016-06-29 株式会社トプコン Ophthalmic photographing apparatus and ophthalmic image processing apparatus
JP5319010B2 (en) 2012-12-28 2013-10-16 株式会社ニデック Ophthalmic imaging equipment
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