JP6824659B2 - Ophthalmologic imaging equipment - Google Patents

Description

The present invention relates to an ophthalmologic imaging apparatus.

Diagnostic imaging occupies an important position in the field of ophthalmology, and in recent years, scanning laser ophthalmoscopes (SLOs) and optical interference tomography have been increasingly used. The SLO is a device that forms an image by scanning the fundus at high speed with a weak laser beam or highly directional light using a confocal optical system, and is used for screening and diagnosis of eye diseases. The optical interference tomography is an optical measuring device that applies a technique called optical coherence tomography (OCT), and forms cross-sectional images, three-dimensional images, and functional images by scanning the two-dimensional and three-dimensional regions of the fundus. To do. The optical interference tomography is also used for imaging the cornea and the like.

When scanning with SLO or OCT, an optotype is presented to the eye to be inspected. The fixation target has a function for directing the line of sight so that a desired portion of the eye to be inspected can be scanned, and a function for fixing the eye to be inspected so that the direction of the line of sight does not change during scanning.

The former function is realized by a configuration that changes the presentation position (fixation position) of the fixation target. In a typical example, a fixation target is displayed on a display device such as a liquid crystal display (LCD), and pixels (groups) corresponding to the fixation position mainly for scanning the macula, mainly for scanning the optic nerve head. Pixels corresponding to the visual position (group), pixels corresponding to the fixation position for scanning a wide range including the macula and the optic nerve head (group), pixels corresponding to the fixation position for scanning the periphery of the fundus (group) Group) etc. are set in advance. At the time of scanning, a fixation target is generated by selectively using pixels (groups) corresponding to a desired portion.

In addition to or in addition to such a display device, a movable light source or a plurality of light sources that can be selectively turned on may be provided. In some cases, means for manually adjusting the fixation position may be provided.

International Publication No. 2013/085042

In recent years, there has been a demand to expand the shooting range by SLO and OCT. To expand the imaging range, not only expand the scope of application of a single scan pattern (raster scan, etc.), but also areas that could not be photographed in the past or areas where good images could not be obtained (for example, macula and optic nerve). It also includes taking a picture of the part far away from the optic disc. Some results have been achieved for the former, but the current situation is that no effective method has been established for the latter.

An object of the present invention is to provide an ophthalmologic imaging apparatus capable of suitably performing a wide range imaging of the fundus.

The ophthalmologic imaging apparatus according to the embodiment includes a scanning optical system, a control unit, an image forming unit, and a moving mechanism. The scanning optical system scans the fundus of the eye to be inspected by the light output from the light source unit including at least a visible light source, and receives the return light from the fundus at the light receiving unit. The control unit controls the scanning optical system. The image forming unit forms an image of the fundus based on the signal from the light receiving unit. The moving mechanism rotates the scanning optical system around the pupil position of the eye to be inspected or a position in the vicinity thereof. The control unit controls the scanning optical system so as to project the visible light output from the visible light source as the fixation light for fixing the eye to be inspected to the fundus. Further, when the scanning optical system is swiveled by the moving mechanism, the control unit controls the scanning optical system so as to move the projection position of the fixation light by a displacement corresponding to the swirling angle.

According to the embodiment, a wide range of imaging of the fundus can be suitably performed.

It is the schematic which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic for demonstrating an example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic for demonstrating an example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic for demonstrating an example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic for demonstrating an example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic for demonstrating an example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic for demonstrating an example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment. It is a flowchart which shows an example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic for demonstrating an example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment.

An exemplary embodiment of the ophthalmologic imaging apparatus will be described below. The contents of the cited references and known techniques can be incorporated into the embodiments.

The ophthalmologic imaging apparatus according to the embodiment scans the posterior segment of the eye with a light beam to acquire a distribution of predetermined data (eg, image, layer thickness distribution, lesion distribution). Examples of such ophthalmologic imaging devices include SLOs and optical interference tomography devices.

The ophthalmologic imaging apparatus according to the embodiment has a function of projecting a fixation target on the fundus. For example, the fixation target can be projected using the same visible light as the visible light for imaging and / or using visible light different from the light for imaging. In addition to such a fixation target projection function, an internal fixation target or an external fixation target similar to the conventional one may be provided.

Hereinafter, unless otherwise specified, the horizontal direction (horizontal direction) is the X direction, the vertical direction (vertical direction) is the Y direction, and the front-back direction (depth direction) is the Z direction when viewed from the subject. The X, Y, and Z directions define a three-dimensional Cartesian coordinate system.

<Composition>
FIG. 1 shows a schematic configuration of an ophthalmologic imaging apparatus according to an embodiment. The ophthalmologic imaging apparatus 1 collects data by scanning the fundus Ef of the eye E to be examined with light, and forms an image of the fundus Ef based on the collected data. In SLO, a front image of the fundus Ef can be obtained. In OCT, a two-dimensional cross-sectional image or a three-dimensional image of the fundus Ef is obtained. The ophthalmologic imaging apparatus may be capable of performing infrared imaging, visible imaging, fluorescence imaging, OCT angiography, Doppler blood flow measurement, and the like.

The ophthalmologic imaging device 1 includes an optical system 2, a moving mechanism 3, a control unit 4, an image forming unit 5, a data processing unit 6, and a user interface (UI) 7.

<Optical system 2>
The optical system 2 includes an optical member and a mechanism for optically collecting data of the fundus Ef. At least, the optical system 2 includes a light source unit 21, a scanning optical system 22, and a light receiving unit 23. In addition to these, for example, at least one of an alignment system for aligning the optical system 2 with respect to the eye E to be inspected and a focus system for focusing the optical system 2 with respect to the eye E to be inspected is included. You may.

The light source unit 21 outputs light for scanning the fundus Ef. The light source unit 21 includes a known light source according to the modality realized by the ophthalmologic imaging apparatus 1. Examples of the light source provided in the light source unit 21 include a semiconductor laser light source (wavelength sweep laser, superluminescent diode, etc.), a solid-state laser, a gas laser, a fiber laser, and other laser light sources. The light source unit 21 may include a plurality of light sources. In this case, for example, a plurality of optical paths from a plurality of light sources are synthesized by a combiner such as an optical fiber combiner or a dichroic mirror. The light source unit 21 includes at least a visible light source, and may further include an invisible light source (for example, an infrared light source).

The scanning optical system 22 scans the fundus Ef with the light output from the light source unit 21. In a typical embodiment, the scanning optics 22 deflects light within a two-dimensional deflection angle range. The dimension in the deflection direction is not limited to two dimensions, and may be one dimension, for example.

The scanning optical system 22 includes an optical scanner. As the optical scanner, a uniaxial deflecting member or a biaxial deflecting member orthogonal to each other is used. Examples of the deflecting member include a galvano mirror, a polygon mirror, a rotating mirror, a dowel prism, a double dowel prism, a rotation prism, and a MEMS mirror scanner. When a biaxial deflection member is used, a deflection member for high-speed scanning (for example, a polygon mirror) and a deflection member for low-speed scanning (for example, a galvano mirror) can be combined.

The scanning optical system 22 further includes an optical element for projecting the light deflected by the optical scanner onto the fundus Ef. In a typical embodiment, the scanning optical system 22 includes a collimating lens, an aperture diaphragm, a beam splitter, an optical scanner, a beam expander, and an objective lens in order from the light source unit 21 side. In addition, optical elements other than these may be included.

The light receiving unit 23 detects the return light of the light projected on the eye E to be inspected by the scanning optical system 22. In a typical embodiment, the light receiving unit 23 includes a condenser lens, a confocal pinhole, and a photodetector provided in an optical path branched by the beam splitter of the scanning optical system 22 described above. The photodetector has a sensitivity according to the wavelength of the light from the light source unit 21. Further, when the ophthalmologic imaging device 1 is used for fluorescence contrast imaging, the photodetector has a sensitivity according to the wavelength of fluorescence emitted by the fundus Ef. In addition, optical elements other than these may be included.

<Movement mechanism 3>
The moving mechanism 3 rotates (rotates) the optical system 2 (particularly the scanning optical system 22) with reference to the pupil position C of the eye E to be inspected. In other words, the moving mechanism 3 moves the optical system 2 along an arc-shaped orbit. The moving mechanism 3 rotates the optical system 2 within a predetermined moving angle range. The center of rotation is not limited to the pupil position C, and may be a position displaced from the pupil position C within a range that does not interfere with scanning of the back eye portion. A position within such a range is called a "position near the pupil position C". The displacement of the vicinity position with respect to the pupil position C may be a displacement in an arbitrary direction in the XYZ space. Hereinafter, unless otherwise specified, "pupil position" means "pupil position or its vicinity position".

In a typical embodiment, the moving mechanism 3 three-dimensionally turns the optical system 2 around the pupil position C within a predetermined moving angle range. Such a moving mechanism 3 includes, for example, one or more holding members for holding the optical system 2 and one or more guide arms movably provided at an arbitrary position within the moving angle range. The holding member slides along the guide arm. The dimension in the turning direction is not limited to three dimensions, and may be, for example, one dimension or two dimensions.

The moving mechanism 3 operates under the control of the control unit 4, for example. In this case, the moving mechanism 3 includes an actuator that generates a driving force for turning the optical system 2 (not shown). The actuator generates a driving force according to a control signal from the control unit 4. This driving force is transmitted by a transmission mechanism (not shown), and the holding member is moved along the guide arm. By such control, the optical system 2 is swiveled in the direction corresponding to the control signal by the angle corresponding to the control signal.

In other embodiments, the moving mechanism 3 does not have to include an actuator. In this case, the rotation of the optical system 2 is performed manually. The position of the optical system 2 is detected by an encoder or a position sensor. The position information acquired in this way is used by, for example, the control unit 4, the image forming unit 5, the data processing unit 6, and the like.

<About other optical systems>
As described above, the optical system 2 may include elements other than the elements shown in FIG. For example, a dedicated fixation system may be provided to realize at least one of internal fixation and external fixation. The fixation system for internal fixation includes, for example, an fixation light source that outputs visible light and an optical path synthesis member that synthesizes an optical path of visible light output from the fixation light source into an optical path of the scanning optical system 22. The fixation system for external fixation is provided at, for example, an arm having one end connected to a face fixing member (not shown) such as a forehead pad or a housing for storing the optical system 2, and the other end of the arm. Including with a visible light source. The configuration of such a fixation system is known.

The alignment system and the focus system also include an optical system for projecting an index (alignment index, focusing index) onto the eye E to be inspected, and an optical system for detecting the return light thereof, as in the conventional case. It should be noted that two or more imaging devices for photographing the anterior segment of the eye E to be inspected are provided, and two or more anterior segment images acquired substantially simultaneously by these imaging devices are analyzed (for example, by using the trigonometry). ) It can also be configured to perform alignment.

<About scanning>
In the optical system 2 as described above, the light output from the light source unit 21 is deflected by the scanning optical system 22 and is imaged as spot light on the fundus Ef through the pupil of the eye E to be inspected. The return light is light that returns to the optical system 2 from the projection position (and its vicinity position) of the spot light. The return light is guided to the light receiving unit 23 and detected by the photodetector. The photodetector generates an electric signal (light receiving signal) by photoelectric conversion. The projection position of the spot light may be described as the spot position.

This series of processes corresponds to the measurement of one point of the fundus Ef. The scanning optical system 22 moves the spot position within a predetermined deflection angle range. That is, the scanning optical system 22 realizes scanning within a predetermined deflection angle range. Further, the moving mechanism 3 rotates the optical system 2 within a predetermined moving angle range. That is, the moving mechanism 3 moves the scan area (single scan area) corresponding to the deflection angle range of the scanning optical system 22. By combining these, it is possible to measure a wide range of fundus Ef while moving a single scan area. Such a scanning operation will be described with reference to FIG.

In the example shown in FIG. 2, reference numeral TA indicates the entire scan area, and reference numeral SA (α, β) indicates the sub-scan area. Let θ _H be the horizontal (for example, X direction) spread of all scan areas TA, and θ _V be the vertical (for example, Y direction) spread. The entire scan area TA is divided into a plurality of sub-scan areas SA (α, β) arranged vertically and horizontally. Here, α = 1,2, ···, A, and β = 1, 2, ···, B, A and B are integers of 1 or more, respectively, and at least one of A and B is. It is an integer of 2 or more. It is not necessary that all of the plurality of sub-scan areas SA (α, β) have the same size and the same shape.

Each sub-scan area SA (α, β) corresponds to a single scan area. A part of the sub-scan area SA (α, β) and a part of the sub-scan area SA (α + 1, β) may overlap, and a part of the sub-scan area SA (α, β) and the sub-scan area may overlap. A part of SA (α, β + 1) may overlap. Using set-theoretic terms, it can be said that the entire scan area TA is covered by a plurality of sub-scan areas SA (α, β). Conversely, it can be said that the union of a plurality of sub-scan areas SA (α, β) defines the entire scan area TA.

In this example, scanning of the entire scan area TA is realized by sequentially scanning a plurality of sub-scan areas SA (α, β). The scanning of each sub-scan area SA (α, β) is executed by the control of the scanning optical system 22, and the sub-scan area SA (α, β) to be scanned is switched by the control of the moving mechanism 3.

Scanning of each sub-scan area SA (α, β) will be described. As described above, the scanning optical system 22 deflects the light from the light source unit 21 within a predetermined deflection angle range. The horizontal spread of this deflection angle range is "2. θ _H1 ", and the vertical spread is "2. θ _V1 ". That is, the scanning optical system 22 can move the spot position by "θ _H1 " in the left-right direction with reference to the center of deflection (for example, the position on the optical axis of the scanning optical system 22), and can move the spot position in the vertical direction, respectively. The spot position can be moved by "θ _V1 ". Since the deflection angle and the distance in the XY plane (the length of the chord) correspond to each other, they can be equated.

Switching of the sub scan area SA (α, β) will be described. As described above, the moving mechanism 3 rotates the optical system 2 within a predetermined movement angle range around the pupil position C. The horizontal spread of this movement angle range is "θ _H2 ", and the vertical spread is "θ _V2 ". That is, the moving mechanism 3 can rotate the optical system 2 by “θ _H2 ” in the horizontal direction, and can rotate the optical system 2 by θ _{V2 in} the vertical direction.

According to the scanning optical system 22 and the moving mechanism 3, when a plurality of sub-scan areas SA (α, β) are arranged without overlapping or gaps, the horizontal moving range of the spot position is θ _H = θ. _{It is H2} +2 · θ _H1 , and the moving range in the vertical direction is θ _V = θ _V2 + 2 · θ _V1 . The area where the horizontal spread is θ _H and the vertical spread is θ _V corresponds to the entire scan area TA. If overlaps or gaps are provided, the entire scan area TA is determined according to the width of the overlaps and the intervals between the gaps.

In one example, θ _H1 = 60 degrees, θ _H2 = 40 degrees, θ _V1 = 40 degrees, and θ _V2 = 40 degrees. As a result, it is possible to scan a range of 160 degrees in the horizontal direction and 120 degrees in the vertical direction. Note that θ _H1 , θ _H2 , θ _V1 , and θ _V2 are determined in consideration of arbitrary factors such as cost and working distance. In particular, it is possible to set the movement range so as not to come into contact with the subject.

<Control unit 4>
The control unit 4 controls each unit of the device. The control unit 4 includes a processor and a storage device (storage circuit). A computer program for controlling the ophthalmologic imaging device 1 is stored in the storage device in advance. This computer program includes a light source control program, a scanning control program, a movement control program, a user interface control program, and the like. When the processor operates according to such a computer program, the control unit 4 executes the control process.

The "processor" is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a Programmable Logic Device), a programmable logic device (for example, a PLC It means a circuit such as Logical Device), FPGA (Field Programmable Gate Array)).

In this embodiment, the scanning as illustrated in FIG. 2 can be realized by controlling the scanning optical system 22 and the moving mechanism 3 in a coordinated manner. An example of such linkage control will be described. The storage device of the control unit 4 stores in advance a default deflection pattern for deflecting the light from the light source unit 21 and a default movement pattern for moving the optical system 2. The deflection pattern and movement pattern may be set by default or may be set by the user. Further, a plurality of deflection patterns and / or a plurality of movement patterns may be arbitrarily combined and applied. The pattern is selected, for example, by the user or the control unit 4.

The control unit 4 sequentially executes the control of the scanning optical system 22 based on the deflection pattern (scanning control) and the control of the moving mechanism 3 based on the moving pattern (moving control). For example, the control unit 4 alternately executes scanning control and movement control. Here, a single scan control corresponds to scanning a single scan area (one sub-scan area), and a single movement control corresponds to switching of sub-scan areas. As another example, the control unit 4 can perform scanning control and movement control in parallel in at least a part of the scanning phases for the entire scanning area.

An example of a scan mode that can be realized in the embodiment will be described. FIG. 3 schematically shows a mode in which the entire scan area AR including the optic disc N and the macula H is divided into a plurality of sub-scan areas and scanned.

The control unit 4 moves the sub-scan area (single scan area) to be scanned in the order of, for example, the sub-scan areas SR1, SR2, SR3, ... By controlling the movement mechanism 3 according to the predetermined movement pattern. Let me. At this time, the adjacent sub-scan areas SRi and SR (i + 1) have overlapping areas CRi (i = 1, 2, 3, ...). When forming an image of the entire scan area AR from a plurality of images obtained from a plurality of sub-scan areas, it is possible to align adjacent images by using the overlapping area. The control unit 4 controls the optical system 2 so as to scan each sub-scan area based on a predetermined deflection pattern. In the example shown in FIG. 3, raster scan is applied. Other examples of the deflection pattern include a circle scan, a concentric circle scan, a radial scan, a slit scan (one-dimensional scan), and the like.

When photographing the fundus Ef, the control unit 4 controls the scanning optical system 22 according to a predetermined scanning pattern while lighting (blinking) the light source included in the light source unit 21 at a predetermined timing.

When shooting with visible light, for example, the control unit 4 executes scanning control for shooting a single scan area with visible light, and only at a timing corresponding to a predetermined fixation position (fixation timing). , The light source unit 21 is controlled so as to output visible light (visible light for fixation) different from visible light for photographing. At the fixation timing, the output of visible light for photographing may be stopped and the visible light for fixation may be output. Alternatively, both visible light for photographing and visible light for fixation may be output at the fixation timing. Visible light for fixation is different from that of visible light for photographing, for example, at least one of wavelength and amount of light.

When shooting with invisible light (infrared light), the control unit 4 executes scanning control for shooting a single scan area with invisible light, and emits visible light for fixation only at a predetermined fixation timing. The light source unit 21 is controlled so as to output.

With the motion control as illustrated above, it is possible to take a picture of a single scan area while keeping the eye E to be inspected fixed. The control of fixation due to the movement of the scan area will be described later.

A specific example of operation control will be described. When taking a picture, the control unit 4 repeatedly controls the scanning optical system 22 according to a predetermined pattern (for example, raster scan), and turns on the visible light source for fixation at a predetermined fixation timing. Examples of such control are shown in FIGS. 4A and 4B. FIG. 4A shows the aspect of the raster scan and the fixation target projected on the fundus Ef. FIG. 4B is a timing chart showing controls for raster scan and projection of fixation targets. In FIG. 4B, the horizontal axis is the time axis.

In the example shown in FIG. 4A, a raster scan consisting of a plurality of (M) parallel line scans L _m (m = 1, 2, ..., M) is applied. Each line scan L _m includes a plurality of scan points (projection points of light beams) arranged in a straight line. The control unit 4 controls the scanning optical system 22 so as to repeat this raster scan.

Further, the control unit 4 turns on the light source unit 21 (visible light source for fixation) at a preset fixation timing. The fixation timing is synchronized with the raster scan. In this example, the fixation timing includes at least the timing at which the optical scanner of the scanning optical system 22 is arranged at the position (direction) corresponding to the njth scan point in the _mjth line scan _Lmj . When the fixation timing includes only this timing, the fixation target T (mj, nj) as a bright spot is projected on the fundus Ef.

In parallel with such projection control of the fixation target, the control unit 4 executes control for photographing the fundus Ef. As a control of fundus photography, the control unit 4 repeatedly turns on the light source unit 21 (visible light source, infrared light source, etc.) at a timing synchronized with the raster scan. In the example shown in FIG. 4A, the control unit 4 sets the light source unit 21 at the timing when the optical scanner is arranged at the position (orientation) corresponding to each of the plurality of scan points set in each of the plurality of line scans L _m. Turn it on. This makes it possible to sequentially scan a plurality of scan points arranged in a grid pattern for raster scan.

The fixation timing is not limited to the timing corresponding to a single scan point. For example, the visible light source can be turned on at a timing corresponding to each of a plurality of spatially adjacent scan points. As an example, the visible light source can be turned on at a timing corresponding to each of a plurality of scan points included in a two-dimensional region such as a disk-shaped region or a cross-shaped region. This two-dimensional region is typically a connected region and more typically a simply connected region.

FIG. 4A shows an example in which a cross-shaped fixation target is presented. More specifically, in the example shown in FIG. 4A, a cross-shaped fixation target centered on the njth scan point in the _mjth line scan _Lmj is presented. The group of scan points corresponding to this fixation timing includes, for example, a plurality of scan points centered on the njth scan point in the line scan L _mj . That is, an odd number of scan points from the (nj−v) th to the (nj + v) th (nj + v) th in the line scan L _mj is included. Here, v is an integer of 1 or more. Further, the group of scan points includes, for example, scan points on a plurality of line scans centered on the line scan L _mj . That is, the scan points on the odd number of line scans from the (mj−w) th to the (mj + w) th are included. Here, w is an integer of 1 or more. Further, the number of corresponding scan points on the _mjth line scan L _mj is 2v + 1 as described above. On the other hand, the number of corresponding scan points on the corresponding line scan other than the line scan L _mj is less than 2v + 1. The number of corresponding scan points in each of the corresponding line scans other than the line scan L _mj may be equal or different. Further, the vertical size of the cross-shaped fixation target is determined by the number of corresponding line scans, and the horizontal size is determined by the number of corresponding scan points on the line scan _Lmj . These are set arbitrarily. For example, the number of corresponding line scans and the number of corresponding scan points on the line scan _Lmj can be set so that the vertical size and the horizontal size of the cross-shaped fixation target are equal (. However, this is not limited to this). Even when another two-dimensional shape of the fixation target is presented, it is possible to similarly set a group of scan points corresponding to the fixation timing.

Further, the control unit 4 can repeatedly execute the same raster scan (imaging control) and the same fixation target projection control.

Further, the control unit 4 repeatedly executes the same raster scan (imaging control) and control for projecting the fixation target at the first fixation position, and after the completion, switches the fixation position, and the same raster scan and the first fixation position are performed. 2 Control for projecting the fixation target at the fixation position can be repeatedly executed. Such control can be sequentially applied to a plurality of fixation positions. That is, the shooting area can be switched by moving the fixation position. A plurality of fixation positions including the first fixation position and the second fixation position are preset as, for example, an imaging protocol. It is also possible to manually set or change the fixation position.

Instead of controlling the raster scan and the movement of the fixation position alternately in this way, it is also possible to apply the control so that the raster scan is repeatedly performed while moving the fixation position continuously or stepwise. ..

_{F k (k = 1,2, ···} ) shown in FIG. 4B represents a single portion of the raster scan (series of line scan _L 1 ~L _M) shown in Figure 4A. In this example, the scanning optical system 22 includes an X scanner, which is an optical scanner that deflects light in the X direction, and a Y scanner, which is an optical scanner that deflects light in the Y direction. One operation of the X scanner corresponds to one line scan L _m . A single operation of the Y scanner corresponds to the movement of the light beam projection position from the line scan L ₁ in the direction orthogonal to the line scan L _m to the line scan L _M. The control unit 4 realizes the operation of the scanning optical system 22 corresponding to the raster scan shown in FIG. 4A by controlling the X scanner and the Y scanner in a coordinated manner. Further, the control unit 4 repeatedly executes the linked control of the X scanner and the Y scanner. As a result, raster scans F ₁ , F ₂ , ... Are executed in sequence.

The control unit 4 executes lighting control of the shooting light source (infrared light source or visible light source) at the shooting timing synchronized with such repetitive raster scan. As a result, an image (frame) corresponding to each raster scan can be acquired.

The control unit 4 is a control synchronized with fixation timing of such a scanning optical system 22 to project the fixation target to the fundus oculi Ef in the control period corresponding to each raster scan F _k.

Even if the fixation target is projected, the scan position may shift due to the influence of eye movements and blinking. In order to deal with such a situation, it is possible to detect the occurrence of eye movements and blinks by analyzing frames sequentially acquired by raster scan and coordinated control of a shooting light source (for example, an infrared light source). it can. Detection of eye movements is performed, for example, based on changes over time in the position of feature sites (optic disc, macula, blood vessels, lesions, laser-treated scars, etc.) in the frame. Blink detection is performed, for example, by whether or not the fundus Ef (for example, a feature portion) is visualized on the frame, or by referring to a predetermined image quality parameter (for example, contrast). When an abnormality such as eye movement or blinking is detected, the control unit 4 can scan the scan point again. At this time, the image recording may be restarted after detecting that the abnormality has been resolved. Alternatively, the fact that an abnormality has been detected may be added to the image data. In addition, when a function for photographing the anterior segment of the eye (for example, the anterior segment imaging camera 123 described later) is provided, an abnormality (eye movement, blinking, etc.) is detected based on the image of the anterior segment acquired by the function. It is possible. For example, eye movement can be detected by obtaining the displacement of a characteristic portion (pupil, etc.) in the frame while photographing the anterior segment of the eye as a moving image. In addition, it can be determined that blinking has occurred when it is determined that at least a part of the feature portion is not drawn on the frame.

The control of fixation associated with switching the scan area will be described. In this embodiment, when the scan area is switched by the rotation of the optical system 2, the control unit 4 controls the optical system 2 so as to move the projection position of the fixation target by the displacement corresponding to the rotation angle. be able to. Examples of such fixation control are shown in FIGS. 5A and 5B.

The switching of the scan area is performed by the control unit 4 or the user. In the former case, the control unit 4 can execute the switching of the scan area (movement control) and the control of fixation in a coordinated manner. In the latter case, the position information of the optical system 2 is input to the control unit 4. For example, the control unit 4 can obtain the turning angle based on the input position information and control the optical system 2 so as to move the projection position of the fixation target by the corresponding displacement.

FIG. 5A shows the switching of the projection position of the fixation target in the transition from the sub-scan area SRi shown in FIG. 3 to the sub-scan area SR (i + 1). In this example, the fixation target is projected at the same position of the fundus Ef before and after switching the scan area. Specifically, the control unit 4, while performing a control for photographing the sub scan area SRi, the light source unit 21 and the scanning optical system to project a fixation target T _i at a predetermined position in the overlapping area CRi 22 is controlled. Furthermore, the control unit 4 controls the moving mechanism 3 to switch the scan area, and the solid in the same position as the fixation target T _i in the overlapping area CR in new sub-scan area SR (i + 1) (i + 1) The light source unit 21 and the scanning optical system 22 are controlled so as to project the optotype Ti _{+ 1} . That is, when superimposing the overlapping area CRi overlapping area CR (i + 1) and, the position of the fixation target _{T i} and the position of the fixation target _{T i + 1} are the same. When such fixation control is applied, the direction of the line of sight of the eye E to be inspected does not change even if the scan area is switched.

On the other hand, it is also possible to project the fixation target at different positions of the fundus Ef before and after switching the scan area. The example shown in FIG. 5B is an fixation control applicable at the time of transition from the sub-scan area SRi to the sub-scan area SR (i + 1) as in FIG. 5A. Control unit 4, while performing a control for photographing the sub scan area SRi, controls the light source unit 21 and the scanning optical system 22 to project a fixation target T _i in place. Further, the control unit 4 controls the moving mechanism 3 so as to switch the scan area, and the light source unit 21 and the light source unit 4 so as to project the fixation target Ti _{+ 1} at a predetermined position in the new sub scan area SR (i + 1). The scanning optical system 22 is controlled. Displacement [Delta] T _i of the fixation target T _{i + 1} with respect to the fixation target T _i is determined based on the turning angle of the optical system 2 for the transition from the sub-scan area SRi to sub scan area SR (i + 1). In this example, the direction of the line of sight of the eye E to be examined changes as the scan area is switched. Here, the displacement ΔT _i can be determined so that the change in the direction of the line of sight becomes small to some extent so that the subject can easily recognize the fixation target after movement.

When the moving mechanism 3 includes the above-mentioned actuator, the control unit 4 can execute the control of the actuator and the control of the optical system 2 for moving the projection position of the fixation light in a coordinated manner. For example, as shown in FIGS. 2 and 3, a plurality of subscan areas, the transition order of these subscan areas, the scan pattern of each subscan area, and the fixation position applied at the time of scanning each subscan area. However, when it is included in the photographing protocol, the control unit 4 controls the actuator (movement mechanism 3) for switching the sub-scan area according to the transition order, and moves the fixation position according to the switching of the sub-scan area. The control of the optical system 2 for the purpose and the control of the optical system 2 for sequentially scanning a plurality of scan points in each sub-scan area can be executed in a coordinated manner. For example, in the example shown in FIG. 3, first, the optical system 2 is swiveled at a position corresponding to the sub-scan area SR1, a fixation target is projected at a position corresponding to the sub-scan area SR1, and a plurality of objects in the sub-scan area SR1 are projected. Scan points (for example, a plurality of scan points arranged in a grid pattern) are sequentially scanned. Next, the optical system 2 is swiveled to a position corresponding to the sub-scan area SR2, a fixation target is projected at a position corresponding to the sub-scan area SR2, and a plurality of scan points in the sub-scan area SR2 are sequentially scanned. Will be done. Such a series of processes is executed in the order of sub scan areas SR1, SR2, SR3, ..., SRN.

<Image forming unit 5>
The image forming unit 5 forms an image of the fundus Ef based on the light receiving signal input from the photodetector of the light receiving unit 23 and the pixel position signal input from the control unit 4, for example, as in the conventional SLO. To do. When the optical system 2 includes an interference optical system for OCT, a cross-sectional image is formed in the same manner as the conventional OCT. The image forming unit 5 includes a storage device that stores an image forming program and a processor that operates according to the image forming program.

<Data processing unit 6>
The data processing unit 6 executes various data processing. An example of data processing is processing of image data formed by the image forming unit 5 or another device. Examples of this processing include image processing, image analysis, image evaluation, and diagnostic support. The data processing unit 6 includes a storage device that stores a data processing program and a processor that operates according to the data processing program. The data processing unit 6 is provided with a setting unit 61. The setting unit 61 will be described later.

<User interface 7>
The user interface (UI) 7 has a function for exchanging information between the user and the ophthalmologic imaging apparatus. The user interface 7 includes a display device and an operation device (input device). Display devices include, for example, a liquid crystal display (LCD). Operating devices include various hardware keys and / or software keys. The control unit 4 receives the operation content for the operation device and outputs a control signal corresponding to the operation content to each unit. It is possible to integrally configure at least a part of the operating device and at least a part of the display device. The touch panel display is an example.

The control unit 4 can display information such as a captured image of the fundus Ef on the display device. The control unit 4 can also display information on a display device provided outside the ophthalmologic imaging apparatus.

<Other controls>
When it is possible to perform moving image shooting (infrared moving image observation, etc.) of the fundus Ef, the control unit 4 monitors the movement of the fundus Ef so that a predetermined part of the fundus Ef is drawn at a fixed position in the image (frame). Tracking control that compensates for eye movements can be performed. Further, the control unit 4 and the data processing unit 6 can perform ex post facto tracking by analyzing the acquired data and correcting the deviation of the drawing position between the images (between frames). Further, the control unit 4 and the data processing unit 6 can detect the line-of-sight direction of the eye E to be inspected and execute tracking control so as to cancel the position shift due to the movement of the line of sight.

<Operation>
An example of the operation of the ophthalmologic imaging apparatus according to the embodiment will be described. An example of the operation is shown in FIG. In this example, the fundus Ef is photographed according to a preset protocol.

The imaging protocol can be set, for example, by selecting a protocol (preset protocol) created in advance and stored in the storage device and making settings for the processor of the control unit 4 to use the protocol, or by setting the eye to be inspected. This is performed by setting the imaging conditions while observing the fundus Ef of E.

The preset protocol includes, for example, at least one of a default set protocol and a user set protocol. Further, the protocol set by another user or the like may be made available via a communication line or a recording medium.

The imaging conditions may include any conditions relating to imaging using an ophthalmologic imaging apparatus. Typical examples are shooting areas (all scan areas), multiple sub-scan areas, their order (movement control conditions), scan patterns (scan control), multiple shooting positions (multiple scan points), and so on. There are shooting order (projection control of shooting light), projection position of fixation target (fixation control), and the like.

(S1: Set the shooting protocol)
In a typical example, the control unit 4 can display the shooting protocol options on the display device of the user interface 7. The user specifies a desired option using the operating device of the user interface 7. The specified shooting protocol is applied to this shooting.

In another example, the control unit 4 can acquire an imaging protocol previously applied to the eye E to be inspected from medical data (electronic medical record or the like) of the patient and display it on a display device. The user inputs whether or not to apply this photographing protocol by using the operating device. Alternatively, the control unit 4 may apply the imaging protocol acquired from the medical data to the current imaging. The shooting protocol setting method is not limited to these examples.

In this example, as shown in FIG. 7, it is assumed that a shooting area composed of sub-scan areas SA (i, j) arranged in 3 rows × 4 columns is set. The order of the sub scan areas SA (i, j) is SA (1,1), SA (1,2), SA (1,3), SA (1,4), SA (2,1), SA ( 2,2), SA (2,3), SA (2,4), SA (3,1), SA (3,2), SA (3,3), SA (3,4) .. The scan pattern is a raster scan, and a plurality of scan points are arranged in a grid pattern, the order of these scan points follows the raster scan, and the fixation position follows the arrangement of the sub scan area SA (i, j). ..

(S2: Move the optical system to the initial turning position)
The control unit 4 controls the moving mechanism 3 so as to arrange the scanning optical system 22 at the turning position corresponding to the first sub-scan area SA (1, 1) designated in step S1.

(S3: Project the fixation target at the initial fixation position)
The control unit 4 projects the fixation target to the first fixation position (fixation position corresponding to the first sub-scan area SA (1, 1)) designated in step S1 so that the light source unit 21 (fixation) (Visible light source) and scanning optical system 22 are controlled. After this stage, the scanning optical system 22 repeats the operation according to the raster scan.

(S4: Alignment)
The control unit 4 performs alignment as described above, for example.

(S5: Photograph the fundus)
After the alignment is completed, the control unit 4 starts controlling the light source unit 21 (photographing light source) and the scanning optical system 22 for photographing the fundus Ef in response to a predetermined imaging start trigger. As a result, the image forming unit 5 forms a front image (raster image) of the area of the fundus Ef corresponding to the sub-scan area SA (1,1).

(S6: Display the captured image)
The control unit 4 displays the captured image obtained in step S5 on the display device of the user interface 7.

(S7: Is shooting completed?)
When scanning (shooting) of all sub-scan areas is completed (S7: Yes), the processing of this example ends (end). In this example, the process ends when the scan of the sub scan areas SA (3, 4) is completed. If not (S7: No), the process proceeds to step S8.

(S8: Rotate the optical system)
The control unit 4 controls the moving mechanism 3 so as to arrange the scanning optical system 22 at the turning position corresponding to the next sub-scan area SA (1, 2). The turning angle at this time is defined as "θ _X ".

Generally, when shifting from the sub-scan area SA (i, j) (j = 1, 2, 3) to the sub-scan area SA (i, j + 1), the scanning optical system 22 has an angle “θ” in the horizontal direction (X direction). Only " _X " is turned. Further, when shifting from the sub scan area SA (i, 4) (i = 1, 2) to the sub scan area SA (i + 1, 1), the scanning optical system 22 has an angle "-3" in the horizontal direction (X direction). -It is swiveled by "θ _X " and is swiveled by an angle "θ _Y " in the vertical direction (Y direction). A horizontal turn may be called a swing, and a vertical turn may be called a tilt.

(S9: Move the fixation position)
The control unit 4 controls the light source unit 21 (visible light source for fixation) and the scanning optical system 22 so as to project the fixation target at the fixation position corresponding to the sub-scan areas SA (1, 2). The amount of movement of the fixation position is an amount corresponding to the turning angle in step S9, and is, for example, an amount for canceling this turning angle.

As a specific example, when the turning angle is “θ _X ”, the fixation position can be moved by a displacement corresponding to the angle “−θ _X ” that cancels the turning angle. If the turning angles are "-3. θ _X " and "θ _Y ", move the fixation position by the displacement corresponding to the angles "3. θ _X " and "-θ _Y " that cancel them. Can be done.

(S10: Photograph the fundus)
The control unit 4 acquires a front image (raster image) of the area of the fundus Ef corresponding to the sub scan areas SA (1, 2) in the same manner as in step S5.

(S11: Combine captured images)
The data processing unit 6 creates a panoramic image representing a plurality of regions that have already been photographed by synthesizing a plurality of already formed frontal images. For example, a panoramic image representing an area corresponding to the first subscan area SA (1,1) and an area corresponding to the second subscan area SA (1,2) is created.

(S12: Display a panoramic image)
The control unit 4 displays the panoramic image obtained in step S11 on the display device of the user interface 7. The process proceeds to step S7.

The control unit 4 causes the ophthalmologic imaging apparatus to repeatedly execute the above routine until it is determined as "Yes" in step S7 (end). When all the sub-scan areas SA (1,1) to SA (3,4) have been photographed, a fundus image showing a wide range corresponding to these sub-scan areas SA (1,1) to SA (3,4). Is obtained and this is displayed.

In the operation example shown in FIG. 6, the scan area is automatically switched (that is, according to the shooting protocol), but the operation is not limited to this. For example, when the scan area is manually switched, a detector for detecting a change in the position of the optical system 2 (that is, a turning angle) is provided, and the detected turning angle is used as a basis (for example, canceling this turning angle). ) The control unit 4 can be configured to execute projection control of shooting light, fixation control, and the like.

<Infrared video observation>
When the infrared moving image observation of the fundus Ef can be performed, various processes can be performed while performing the infrared moving image observation. Infrared moving image observation is performed in the same manner as a general SLO, for example, an infrared light source for photographing provided in a light source unit 21, a scanning optical system 22, a light receiving unit 23, an image forming unit 5, and a control unit 4. And the display device of the user interface 7.

The control unit 4 includes, for example, control of an infrared light source for photographing, control of a visible light source for fixation, control of a scanning optical system 22, control of a light receiving unit 23, control of an image forming unit 5, and a display device. Control can be executed in a coordinated manner. The control of the infrared light source for photographing (imaging timing), the control of the visible light source for fixation (fixation timing), and the control of the scanning optical system 22 (X scanner, Y scanner) are, for example, the drawings of the above embodiment. It is executed in the same manner as the timing chart of 4B. In parallel with these controls, the control unit 4 controls the light receiving unit 23, the image forming unit 5, and the display device.

The infrared light source for photographing may be any infrared light source, and for example, a stationary light source (continuous light source) or an instantaneous light source (pulse light source) is used for this. When a stationary light source is used, the detection rate of the light receiving unit 23 (photodetector) affects the scan rate (shooting timing). When an instantaneous light source is used, its blinking rate affects the scan rate (shooting timing).

Each time a scan for one frame (raster scan or the like) is completed, the image forming unit 5 forms one frame from the data collected by this scan and sequentially sends it to the control unit 4. The control unit 4 displays an infrared moving image by sequentially displaying frames sequentially input from the image forming unit 5 at regular time intervals on a display device. As a result, the user can observe the fundus Ef in real time.

By referring to the infrared moving image acquired in this way, it is possible to control the fixation position according to the rotation of the optical system 2. It is also possible to perform these controls by referring to an image other than the infrared moving image. For example, an image acquired using visible light can be used.

An example of controlling the fixation position based on an infrared moving image will be described. This control is executed by the control unit 4, the data processing unit 6 (setting unit 61), and the like. When the optical system 22 is swiveled by the moving mechanism 3, the setting unit 61 determines the projection position of the fixation light before the rotation (fixation position), the infrared image obtained before the rotation (first frame), and the infrared image (first frame). The fixation position of the fixation light after the rotation is set based on the infrared image (second frame) obtained after the rotation.

This process includes, for example, a process of identifying a position (feature position) in a frame corresponding to a feature site (optic disc, macula, blood vessel, lesion, scar of laser treatment, etc.) and a feature position in the first frame. It may further include a process of obtaining the displacement between the feature position in the second frame and a process of obtaining the fixation position after turning based on the fixation position before turning and the displacement.

The process of obtaining the fixation position after turning from the fixation position before turning and the displacement after turning may include, for example, a process of obtaining the turning angle from the displacement. In addition, the fixation position after turning can be obtained so as to cancel the displacement, that is, the fixation position before turning and the fixation position after turning are the same. Further, the fixation position after turning can be obtained so that the fixation position after turning is arranged at a predetermined position with reference to the fixation position before turning.

The control unit 4 can control the scanning optical system 22 so as to move the fixation light to the fixation position after turning set by the setting unit 61. According to such an example, when the optical system 2 is swiveled, the fixation light can be automatically moved to the projection position set by referring to the infrared moving image. As a method of moving the fixation position, there is also a method of using the rotation of the scanning optical system 22 in addition to or instead of controlling the scanning optical system 22.

The process of setting the fixation position after turning is not limited to this. For example, an infrared moving image or its frame can be displayed on a display device, or the fixation position before turning can be displayed on this display image. The user can specify the fixation position after turning by referring to the displayed information. Alternatively, the fixation position after turning obtained by the data processing unit 6 may be displayed on the display device together with the infrared moving image or the like so that the fixation position can be adjusted manually.

<About changing the size of a single scan area>
The size of a single scan area is defined by the deflection angle range of the scanning optics, which is primarily determined by the deflection angle of the optical scanner. On the other hand, it is possible to provide an attachment for changing the size of a single scan area. For example, an optical unit that can be selectively used for changing the scanning range (angle of view, magnification) by the scanning optical system can be provided.

Examples of such scanning optics and optical units are shown in FIGS. 8-10. The ophthalmologic imaging apparatus of this example can operate in a wide-angle imaging mode and a high-magnification imaging mode. The switching of the angle of view is realized by selectively using optical units having different refractive powers.

FIG. 8 shows an example of an optical system in the wide-angle shooting mode. FIG. 9 shows an example of an optical unit (objective lens system) for switching the angle of view. FIG. 10 shows an example of the optical system of the ophthalmologic imaging apparatus in the high magnification imaging mode. Reference numeral P in FIGS. 8 and 10 indicates a position optically conjugate with the fundus Ef (fundus conjugate position), and reference numeral Q indicates a position optically conjugate with the pupil of the eye E to be inspected (pupil conjugate position). ..

The optical system 100 is an example of the optical system 2 shown in FIG. 1, and data is collected by scanning the fundus Ef using a light beam. Therefore, the optical system 100 includes a projection system that projects a light beam onto the eye E to be inspected via the objective lens system 110 and a light receiving system that receives the return light of the projected light beam through the objective lens system 110. Including. An image of the fundus Ef is formed based on the output from the light receiving system. The optical system 100 includes an SLO optical system 130 and an OCT optical system 140. The SLO optical system 130 includes an SLO projection system and an SLO light receiving system. The OCT optical system 140 includes an OCT projection system and an OCT light receiving system.

The ophthalmologic imaging apparatus of this example is provided with an anterior segment imaging system 120 for observing and photographing the anterior segment. The optical system 100, the objective lens system 110, and the anterior segment imaging system 120 are moved in the X, Y, and Z directions. The anterior segment image obtained by the anterior segment imaging system 120 is used for alignment and tracking.

In the exemplary embodiment, an objective lens unit is prepared for each shooting mode, and the objective lens unit corresponding to the selected shooting mode is selectively used. In this example, as shown in FIG. 9, the objective lens unit 110A for the wide-angle shooting mode (for example, an angle of view of 100 degrees) and the objective lens unit 110B for the high magnification shooting mode (for example, an angle of view of 50 degrees) are It is selectively arranged in the optical path of the optical system 100.

The objective lens system 110 includes an angle of view changing mechanism 115 in addition to the objective lens units 110A and 110B. The angle of view changing mechanism 115 includes, for example, a known rotation mechanism or sliding mechanism, and selectively (exclusively) arranges the objective lens units 110A and 110B in the optical path. The angle of view changing mechanism 115 arranges the objective lens unit 110A (110B) in the optical path so that the optical axis of the objective lens unit 110A (110B) substantially coincides with the optical axis O of the optical system 100.

The angle of view changing mechanism 115 may include a configuration for manually moving the objective lens units 110A and 110B. In this case, it is possible to provide a type detection unit for detecting the type of the objective lens unit arranged in the optical path, specify the shooting mode from the detection result, and execute the control according to the specific result. The angle of view changing mechanism 115 may include a configuration for electrically (and automatically) moving the objective lens units 110A and 110B. In this case, the control unit 4 sends a control signal for arranging the objective lens unit corresponding to the selected shooting mode in the optical path to the angle of view changing mechanism 115.

The objective lens unit 110A for the wide-angle shooting mode includes lenses 111A and 112A, a dichroic mirror DM1A, and a concave lens 113A. The dichroic mirror DM1A couples the optical path of the optical system 100 and the optical path of the anterior segment imaging system 120. The dichroic mirror DM1A transmits the light guided by the optical system 100 and reflects the light for anterior segment imaging. A fundus conjugate position P is arranged between the dichroic mirror DM1A and the concave lens 113A.

The objective lens unit 110B for the high magnification shooting mode includes a lens 111B and a dichroic mirror DM1B. The dichroic mirror DM1B has the same function as the dichroic mirror DM1A.

The dichroic mirror DM1A and the dichroic mirror DM1B are arranged at (almost) the same position in the optical path of the optical system 100. As a result, it is not necessary to adjust the position and orientation of the anterior segment imaging system 120 when the imaging mode is switched.

In an exemplary embodiment, a single dichroic mirror can be configured to be shared by multiple objective lens units. For example, in the example shown in FIG. 9, the dichroic mirrors DM1A and DM1B may be the same member. That is, a configuration can be applied in which the objective lens unit 110A including only the lenses 111A and 112A and the concave lens 113A and the objective lens unit 110B including only the lens 111B are selectively used.

The objective lens system 110 can be moved along the optical axis O. That is, the objective lens system 110 can be moved in the Z direction with respect to the optical system 100. As a result, the focal position of the SLO optical system 130 and the focal position of the OCT optical system 140 are changed.

In an exemplary embodiment, three or more objective lens units can be selectively used. For example, an objective lens unit for a high magnification shooting mode, a medium magnification shooting mode, and a low magnification shooting mode, and an angle of view changing mechanism for selectively arranging these in the optical path may be provided.

Hereinafter, a state in which the objective lens unit 110A is arranged in the optical path will be mainly described. Unless otherwise specified, the same or similar matters in the state where the objective lens unit 110B is arranged will be omitted.

The anterior segment imaging system 120 includes an anterior segment illumination light source 121, a lens 122, an anterior segment imaging camera 123, an imaging lens 124, and a beam splitter BS1. The beam splitter BS1 combines the optical path of the anterior segment illumination light and the optical path of its return light.

The anterior segment illumination light source 121 includes an infrared light source such as an infrared LED. The anterior segment illumination light emitted by the anterior segment illumination light source 121 is refracted by the lens 122, reflected by the beam splitter BS1 toward the dichroic mirror DM1A, and reflected by the dichroic mirror DM1A toward the eye E to be inspected. The return light of the anterior segment illumination light from the eye E to be examined is reflected by the dichroic mirror DM1A, transmitted through the beam splitter BS1, and focused on the anterior segment imaging camera 123 (detection surface of the imaging element) by the imaging lens 124. Will be done. The detection surface of the image sensor is arranged at the pupil conjugate position Q (or its vicinity). The image sensor is, for example, a CCD image sensor or a CMOS image sensor.

The optical path of the SLO optical system 130 and the optical path of the OCT optical system 140 are coupled by a dichroic mirror DM2. In an exemplary embodiment, at least part of the SLO optical system 130 is a telecentric optical system and at least a part of the OCT optical system 140 is a telecentric optical system, and the optical paths of these telecentric optical systems are coupled by a dichroic mirror DM2. To. According to this example, even if the objective lens system 110 is moved to change the focal position of the optical system 100, the aberration of the pupil (for example, the exit pupil by the objective lens system 110) does not increase, so that the focus adjustment is facilitated. be able to.

The SLO optical system 130 includes a light source unit 131, a collimating lens 132, a beam splitter BS2, a condenser lens 133, a confocal diaphragm 134, a detector 135, an optical scanner 136, and a lens 137. The beam splitter BS2 combines the optical path of the SLO light projected on the eye E to be examined and the optical path of the return light thereof.

The light source unit 131 is an example of the light source unit 21 of FIG. 1, and includes a laser diode, a super luminescent diode, a laser driven light source, and the like. The light source unit 131 outputs light having a wavelength that can be used for the SLO. The light source unit 131 includes at least a visible light source. Visible light sources include at least one visible light source. When a visible light source for photographing and a visible light source for fixation are provided, these may be common light sources. The light source unit 131 may be configured to be able to selectively output light of different wavelength bands. Further, it may be configured so that two or more lights having different wavelength bands can be output in parallel. An example in which the light source unit 131 can output infrared light, red light, green light, and blue light will be described later. The light source unit 131 is arranged at the fundus conjugate position P (or its vicinity).

The optical scanner 136 includes an X scanner 136X that deflects light in the X direction and a Y scanner 136Y that deflects light in the Y direction. One of the X scanner 136X and the Y scanner 136Y is a low-speed scanner (galvano mirror, etc.), and the other is a high-speed scanner (resonant mirror, polygon mirror, MEMS mirror, etc.). The reflective surface of the Y scanner 136Y is arranged at the pupil conjugate position Q (or its vicinity).

The opening formed in the confocal diaphragm 134 is arranged at the fundus conjugate position P (or its vicinity). The detector 135 includes, for example, an avalanche photodiode or a photomultiplier tube.

The light beam (SLO light) output from the light source unit 131 is converted into a parallel light beam by the collimating lens 132, is transmitted through the beam splitter BS2, is deflected by the optical scanner 136, is refracted by the lens 137, and is transmitted through the dichroic mirror DM2. , Is projected onto the fundus Ef via the objective lens system 110. The return light of the SLO light projected on the fundus Ef travels in the same optical path in the opposite direction, is guided to the beam splitter BS2, is reflected by the beam splitter BS2, is focused by the condenser lens 133, and is focused on the cofocal aperture 134. It passes through the opening and is detected by the detector 135.

The OCT optical system 140 includes a focusing lens 141, an optical scanner 142, a collimating lens 143, and an interference optical system 150.

The focusing lens 141 is moved along the optical axis of the OCT optical system 140. As a result, the focal position of the OCT optical system 140 is changed independently of the SLO optical system 130. After the focusing state of the SLO optical system 130 and the OCT optical system 140 is adjusted by moving the objective lens system 110, the focusing state of the OCT optical system 140 can be finely adjusted by moving the focusing lens 141.

The optical scanner 142 includes an X scanner 142X that deflects light in the X direction and a Y scanner 142Y that deflects light in the Y direction. Each of the X scanner 142X and the Y scanner 142Y is, for example, a galvano mirror. The intermediate position between the two optical scanners 142X and 142Y corresponds to the pupil conjugate position Q (or its vicinity).

The collimating lens 143 guides the OCT light (measurement light) emitted from the fiber end c3 of the optical fiber f4 to the optical scanner 142 as a parallel luminous flux, and collects the return light of the measurement light from the fundus Ef toward the fiber end c3. It glows.

The interferometric optical system 150 includes an OCT light source 151, fiber couplers 152 and 153, a reference prism 154, and a detector 155. The interferometric optics 150 comprises, for example, a configuration for performing a swept source OCT or a spectral domain OCT. In swept source OCT, a tunable light source is used as the OCT light source 151, and a balanced photodiode is used as the detector 155. In the spectral domain OCT, a low coherence light source (broadband light source) is used as the OCT light source 151, and a spectroscope is used as the detector 155.

The OCT light source 151 emits, for example, a light beam L0 that emits light having a center wavelength of 1050 nm. The light L0 is guided by the fiber coupler 152 through the optical fiber f1 and is divided into the measurement light LS and the reference light LR.

The reference light LR is emitted from the fiber exit end c1 through the optical fiber f2, is converted into a parallel light flux by the collimating lens 156, is folded back by the reference prism 154, is converted into a focused light flux by the collimating lens 157, and is incident on the fiber incident end c2. It is guided to the fiber coupler 153 through the optical fiber f3. The reference prism 154 is moved to change the optical path length of the reference light LR as in the conventional case. Further, a polarization controller, an attenuator, an optical path length correction member, and a dispersion compensation member may be provided in the optical path of the reference light.

On the other hand, the measurement light LS generated by the fiber coupler 152 is emitted from the fiber end c3 through the optical fiber f4, becomes a parallel light beam by the collimated lens 143, passes through the optical scanner 142 and the focusing lens 141, and is transmitted by the dichroic mirror DM2. It is reflected, refracted by the objective lens system 110, and projected onto the fundus Ef. The measurement light LS is reflected and scattered at various depth positions of the fundus Ef. The return light of the measurement light LS including the backscattered light travels in the opposite direction along the same path, is guided to the fiber coupler 152, and reaches the fiber coupler 153 through the optical fiber f5.

The fiber coupler 153 superimposes the measurement light LS incident through the optical fiber f5 and the reference light LR incident through the optical fiber f3 to generate interference light. 8 and 10 show the case of swept source OCT. The fiber coupler 153 branches the interference light at a predetermined branching ratio (for example, 1: 1) to generate a pair of interference light LCs. The pair of interference light LCs are detected by a detector 155 (balanced photodiode). In the case of spectral domain OCT, the detector 155 (spectrometer) decomposes the interference light generated by the fiber coupler 153 into a plurality of wavelength components and detects them.

The detector 155 sends the result (detection signal) of detecting the pair of interference light LCs to a DAC (Data Acquisition System) (not shown). A clock is supplied to the DAC from the OCT light source 151. This clock is generated in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by a tunable light source. The DAQ samples the detection signal based on this clock. The sampling result is sent to the processor for forming the OCT image.

The ophthalmologic imaging apparatus of this example includes a moving mechanism 3 similar to that in FIG. 1, a processing system (control unit 4, image forming unit 5, data processing unit 6), and a user interface 7. The processing system executes the same control and data processing as the ophthalmologic imaging apparatus shown in FIG. Further, in this example, the control unit 4 may be configured to control the angle of view changing mechanism 115.

<Other examples of optical systems>
An ophthalmologic imaging apparatus capable of outputting light beams in a plurality of wavelength bands will be described. An example of a part of the optical system of such an ophthalmologic imaging apparatus is shown in FIG. Unless otherwise specified, the above drawings and explanations apply mutatis mutandis.

The optical system shown in FIG. 11 represents an SLO light source unit 131A applied in place of the light source unit 131 and the collimating lens 132 of FIGS. 8 and 10. Other parts may be the same as in the above embodiment.

The SLO light source unit 131A is an example of the light source unit 21 of FIG. 1, and can output both infrared light and visible light. The SLO light source unit 131A includes an infrared light source 131a, a red light source 131r, a green light source 131g, and a blue light source 131b. The infrared light source 131a outputs a light beam in the (near) infrared band. The red light source 131r outputs a light beam in the red band. The green light source 131 g outputs a light beam in the green band. The blue light source 131b outputs a light beam in the blue band. Each of these light sources 131a, 131r, 131g and 131b is, for example, a semiconductor laser.

The infrared light output from the infrared light source 131a is converted into a parallel luminous flux by the collimating lens 132a. The red light output from the red light source 131r is converted into a parallel luminous flux by the collimating lens 132r. The green light output from the green light source 131 g is converted into a parallel luminous flux by the collimating lens 132 g. The blue external light output from the blue light source 131b is converted into a parallel luminous flux by the collimating lens 132b.

The beam splitter BSr synthesizes red light converted into a parallel luminous flux by the collimating lens 132r into an optical path of infrared light converted into a parallel luminous flux by the collimating lens 132a. The beam splitter BSg synthesizes green light converted into a parallel luminous flux by the collimating lens 132g into an optical path of infrared light converted into a parallel luminous flux by the collimating lens 132a. The beam splitter BSb synthesizes blue light converted into a parallel luminous flux by the collimating lens 132b into an optical path of infrared light converted into a parallel luminous flux by the collimating lens 132a. The three beam splitters BSr, BSg and BSb synthesize the optical paths of four light beams having different wavelength bands. This combined optical path is led to the beam splitter BS2.

The control unit 4 controls each of the infrared light source 131a, the red light source 131r, the green light source 131g, and the blue light source 131b. The control unit 4 may include a synchronization circuit for synchronously controlling the light sources 131a, 131r, 131g and 131b. This synchronization circuit may be configured to synchronize the control of the light sources 131a, 131r, 131g and 131b with the control of the optical system 100 (particularly the optical scanner 136).

According to the ophthalmologic imaging apparatus of this example, infrared moving image observation can be performed by controlling the infrared light source 131a and the visible light source (at least one of the red light source 131r, the green light source 131g, and the blue light source 131b) in parallel. The projection of the fixation target can be performed in parallel.

Infrared moving image observation is performed, for example, as follows. The control unit 4 controls the infrared light source 131a so as to output infrared light at predetermined time intervals while repeatedly controlling the optical scanner 136 corresponding to a predetermined scan pattern (raster scan or the like). The image forming unit 5 forms one frame based on the data collected in one scan pattern. The image forming unit 5 sequentially creates frames in synchronization with the scanning repetition rate.

In parallel with the control for observing the infrared moving image, the control unit 4 can execute the control for projecting the fixation target. The projection control of the fixation target is executed, for example, in the same manner as the timing chart of FIG. 4B of the above embodiment. That is, the control unit 4 projects the fixation target on the fundus Ef during the control period corresponding to each frame at the fixation timing synchronized with the control for infrared moving image observation.

In the ophthalmologic imaging apparatus of this example, it is possible to correct the projection position of the fixation light in real time, interrupt or stop the imaging, etc., while monitoring the fixation deviation of the eye E to be inspected. Therefore, the data processing unit 6 obtains the displacement of the fundus Ef by analyzing the frame repeatedly formed by the image forming unit 5. This analysis process is performed, for example, when the pixel value of the frame is analyzed to obtain the position (coordinates in the frame) of the characteristic part (optic disc, blood vessel, diseased part, etc.) and the position of the characteristic part between different frames. Includes processing for finding series changes.

The time-series displacement of the featured portion identified in this way corresponds to the change in the fixation state of the eye E to be inspected. When the displacement of the feature portion becomes equal to or more than a predetermined threshold value, the data processing unit 6 determines that the fixation deviation has occurred. The displacement (displacement direction, displacement amount) at that time is sent to the control unit 4.

The displacement of the feature portion is calculated as, for example, a displacement with respect to a predetermined reference frame. The reference frame may be, for example, the first frame acquired after the shooting conditions are met. Further, the reference frame may be updated as appropriate while observing the infrared moving image.

The control unit 4 can reflect the displacement obtained by the data processing unit 6 in the fixation control and the imaging control. This displacement represents the direction and amount of fixation deviation of the eye E to be inspected. The control unit 4 controls the lighting timing of the visible light source (one or more of the red light source 131r, the green light source 131g, and the blue light source 131b that outputs the fixation light) so as to cancel this displacement. That is, the control unit 4 converts the shift of the spatial position called the fixation shift into the shift of the temporal position called the change of the fixation timing. The relationship between the spatial position and the temporal position is clear from FIGS. 4A and 4B and their explanations.

<Action / effect>
The typical operation and effect of the ophthalmologic imaging apparatus according to the embodiment will be described.

The ophthalmologic imaging apparatus according to the embodiment includes a scanning optical system, a control unit, an image forming unit, and a moving mechanism. The scanning optical system (for example, the scanning optical system 22) scans the fundus of the eye to be inspected by the light output from the light source unit (for example, the light source unit 21) including at least a visible light source, and receives the return light from the fundus of the eye (for example, the light receiving unit). The light is received by the unit 23). The scanning optical system is controlled by a control unit (for example, control unit 4). The image forming unit (for example, the image forming unit 5) forms an image of the fundus based on the signal from the light receiving unit. The moving mechanism (for example, the moving mechanism 3) rotates the scanning optical system around the pupil position of the eye to be inspected or a position in the vicinity thereof. The control unit controls the scanning optical system so as to project the visible light output from the visible light source as the fixation light for fixing the eye to be inspected to the fundus.

According to such an ophthalmologic imaging apparatus, the fixation target can be projected by a swivel scanning optical system. Therefore, it is possible to perform a wide range of scanning (imaging) by rotating the scanning optical system while projecting the fixation target by the scanning optical system. Further, since the fixation target can be projected by the scanning optical system, it is possible to suitably photograph the fundus without providing a means dedicated to fixation, and it is also possible to make the device compact.

In the embodiment, when the scanning optical system is swiveled by the moving mechanism, the control unit can control the scanning optical system so as to move the projection position of the fixation light by a displacement corresponding to the swirling angle.

According to such a configuration, the fixation target can be moved according to the turning angle of the scanning optical system. Therefore, it is possible to preferably perform the transition of the fixation position with the rotation of the scanning optical system.

In the embodiment, when the moving mechanism includes an actuator that generates a driving force for rotating the scanning optical system, the control unit controls the actuator and controls the scanning optical system for moving the projection position of the fixation light. Can be executed in a coordinated manner.

According to such a configuration, the rotation of the scanning optical system and the movement of the fixation target can be controlled in a coordinated manner. Therefore, it is possible to automatically and preferably perform the transition of the fixation position due to the rotation of the scanning optical system.

In the embodiment, when the light source unit further includes an infrared light source, the scanning optical system scans the fundus with the infrared light output from the infrared light source, and the return light of the infrared light from the fundus is sent to the light receiving unit. The image forming unit can form an image of the fundus of the eye based on the signal from the light receiving unit that receives the return light of the infrared light. Further, the control unit controls the scanning optical system so as to perform scanning by infrared light and projection of fixation light in a coordinated and repetitive manner, and is based on the repetitive scanning of infrared light by the image forming unit. The formed image can be displayed as a moving image on the display means.

According to such a configuration, it is possible to observe an infrared moving image of the fundus while projecting a fixation target. Therefore, stable moving image observation in which the fixation deviation is suppressed can be performed.

The display means is provided inside or outside the ophthalmologic imaging apparatus. As an example of the internal display means, there is a display device of the user interface 7. An example of an external display means is a display device connected to an ophthalmologic imaging device.

The ophthalmologic imaging apparatus according to the embodiment may include a setting unit. When the scanning optical system is swiveled by the moving mechanism, the setting unit (for example, the setting unit 61) swivels the projection position of the fixation light before the swivel, the image based on the scanning of the infrared light performed before the swivel, and the swivel. The projection position of the fixation light after turning is set based on the image based on the scanning of the infrared light performed later. The control unit can control the scanning optical system so as to move the fixation light to the projection position set by the setting unit.

According to such a configuration, the fixation position after the turning of the scanning optical system can be set by referring to the infrared images actually acquired before and after the turning of the scanning optical system. Therefore, it is possible to preferably perform the transition of the fixation position with the turning.

The ophthalmologic imaging apparatus according to the embodiment may further include an optical unit (for example, objective lens units 110A and 110B) for changing the size of the scanning range by the scanning optical system.

According to such a configuration, the degree of freedom in shooting can be improved.

The embodiments shown above are merely examples for carrying out the present invention. A person who intends to carry out the present invention can make arbitrary modifications, omissions, additions, etc. within the scope of the gist of the present invention.

1 Ophthalmic imaging device 2 Optical system 21 Light source unit 22 Scanning optical system 23 Light receiving unit 3 Moving mechanism 4 Control unit 5 Image forming unit 6 Data processing unit 61 Setting unit 7 User interface

Claims (3)

A scanning optical system that scans the fundus of the eye to be inspected with light output from a light source unit that includes at least a visible light source, and receives the return light from the fundus at the light receiving unit.
A control unit that controls the scanning optical system and
An image forming unit that forms an image of the fundus based on a signal from the light receiving unit,
It is provided with a moving mechanism for rotating the scanning optical system around the pupil position of the eye to be inspected or a position in the vicinity thereof.
The control unit controls the scanning optical system so as to project visible light output from the visible light source onto the fundus of the eye as fixation light for fixing the eye to be inspected , and the movement mechanism causes the control unit to perform the scanning optical system. An optometry imaging apparatus characterized in that when the scanning optical system is swiveled, the scanning optical system is controlled so as to move the projection position of the fixation light by a displacement corresponding to the swirling angle . A scanning optical system that scans the fundus of the eye to be inspected with light output from a light source unit that includes at least a visible light source, and receives the return light from the fundus at the light receiving unit.
A control unit that controls the scanning optical system and
An image forming unit that forms an image of the fundus based on a signal from the light receiving unit,
It is provided with a moving mechanism for rotating the scanning optical system around the pupil position of the eye to be inspected or a position in the vicinity thereof.
The control unit controls the scanning optical system so as to project visible light output from the visible light source as fixation light for fixing the eye to be inspected to the fundus .
The light source unit further includes an infrared light source.
The scanning optical system scans the fundus with infrared light output from the infrared light source, and receives the return light of the infrared light from the fundus at the light receiving unit.
The image forming unit forms an image of the fundus based on a signal from the light receiving unit that has received the return light of the infrared light.
The control unit controls the scanning optical system so as to perform scanning by the infrared light and projection of the fixation light in a coordinated and repetitive manner, and based on the repetitive scanning of the infrared light. An ophthalmologic photographing apparatus characterized in that an image formed by an image forming unit is displayed as a moving image on a display means . When the scanning optical system is swiveled by the moving mechanism, the projection position of the fixation light before the swirl, an image based on the scanning of the infrared light performed before the swivel, and the red color performed after the swivel. Further provided with a setting unit for setting the projection position of the fixation light after turning based on the image based on the scanning of the external light.
The ophthalmologic imaging apparatus according to claim 2 , wherein the control unit controls the scanning optical system so as to project the fixation light at the projection position set by the setting unit.