JP6899632B2 - 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. Fundus cameras, scanning laser ophthalmoscopes (SLOs), and slit lamp microscopes have been conventionally used for ophthalmologic image diagnosis, but in recent years, optical coherence tomography (OCT) has been increasingly used. A fundus camera is a device that photographs the fundus with a digital camera. The SLO is a device that forms an image by scanning the fundus with a weak laser beam at high speed. A slit lamp microscope is a device for projecting slit light onto the anterior segment of the eye and observing and photographing the projection surface (cross section) from an oblique direction. OCT is a technique of projecting measurement light onto the fundus or anterior segment of the eye, superimposing the return light on the reference light to generate interference light, and forming an image from the detection data of the interference light. OCT not only acquires B-mode images and 3D images of the eye to be inspected, but also constructs front images (en-face images) such as C-mode images and shadowgrams, and constructs blood vessel-enhanced images (angiograms). It is also used for blood flow measurement and evaluation of the size and morphology of eye tissue. The evaluation targets include axial length, angle, corneal thickness, retinal thickness, optic disc shape, nerve tract, and blood vessel tract.

In ophthalmic diagnostic imaging, a wide area may be photographed or multiple parts may be photographed. Such imaging is realized by changing the fixation position of the eye to be inspected. As a typical example, after performing the first imaging with the first fixation position applied, the second imaging is executed by changing to the second fixation position. By repeating such a process a desired number of times, data in a plurality of ranges of the eye to be inspected can be collected. The change of the fixation position is realized by changing the projection position of the fixation target.

When the fixation position is changed, the eyeball rotates in order to catch the fixation target after movement in the fovea centralis, and the alignment and focus states change. When the alignment state changes, there is a problem that a part or all of the light flux for fundus photography is eclipsed by the iris, and the alignment must be performed again. Similarly, if the focus state changes, refocusing is required.

Further, when OCT of the fundus is performed, if the alignment state is adjusted after the fixation position is changed, the fundus to be measured moves in the optical axis direction of the measurement light, so that the measurement range in the optical axis direction (referred to as the measurement optical path length). There are new problems such as the fundus of the eye deviating from the measurement optical path range where the optical path length is almost equal to the optical path length, and the measurement sensitivity is lowered.

The OCT apparatus disclosed in Patent Document 1 is known as a technique for solving the above problems. This OCT device estimates the amount of alignment deviation and the amount of deviation of the optical path length difference between the measurement light and the reference light from the estimated amount of rotation of the eye to be inspected caused by the change of the fixation position, and is based on these deviation amounts. It is configured to adjust the alignment and the optical path length difference.

Japanese Patent No. 5836564

However, considering that there are individual differences in the size of the eyeball and the position of the center of rotation, it is difficult to accurately obtain the deviation amount of the alignment and the optical path length difference from the change in the fixation position. That is, when the invention according to Patent Document 1 is applied to actual photographing, there is a possibility that the imaging conditions cannot be accurately adjusted due to the change in the fixation position.

An object of the ophthalmologic imaging apparatus according to the present invention is to accurately adjust imaging conditions according to a change in the fixation position.

The ophthalmologic imaging apparatus of the embodiment includes an image acquisition unit, an optometry optical system, an optical system moving unit, a first position detection unit, and a control unit. The image acquisition unit includes an optical system that projects light onto the eye to be inspected and detects the return light, and acquires an image of the eye to be inspected from the detection result obtained by the optical system. The fixation optical system projects an fixation light beam corresponding to a preset fixation position onto the eye to be inspected. The optical system moving unit moves the optical system. The first position detection unit acquires a live image of the anterior segment of the eye to be inspected, and based on this live image, the displacement at a relative position between the optical axis of the optical system and the center of the pupil of the eye to be inspected is used as the position of the eye to be inspected. To detect. After the fixation optical system projects the fixation beam corresponding to the new fixation position onto the eye to be inspected, the first position detection unit acquires a live image of the anterior segment and determines the size of the pupil region in this live image. Based on this, the position of the eye to be inspected is detected. The control unit controls the optical system moving unit based on this detection position.

According to the ophthalmologic imaging apparatus according to the embodiment, it is possible to accurately adjust the imaging conditions according to the change in the fixation position.

The schematic diagram which shows the example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. The schematic diagram which shows the example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. The schematic diagram which shows the example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. The schematic diagram which shows the example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. The flow chart which shows the example of the operation of the ophthalmologic imaging apparatus which concerns on embodiment.

An exemplary embodiment of the present invention will be described in detail with reference to the drawings. The ophthalmologic imaging apparatus according to the embodiment includes an optical system for acquiring an image of the eye to be inspected, and includes, for example, an OCT apparatus, a fundus camera, an SLO, or the like. Hereinafter, an example in which the swept source OCT and the fundus camera are combined will be described, but the embodiment is not limited to this. For example, a spectral domain OCT using a low coherence light source and a spectroscope can be adopted instead of the swept source OCT.

<Constitution>
As shown in FIG. 1, the ophthalmologic imaging apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The fundus camera unit 2 is provided with an optical system and a mechanism for acquiring a front image of the eye to be inspected E (anterior eye portion Ea, fundus Ef). The OCT unit 100 is provided with an optical system and a mechanism for executing OCT. The arithmetic control unit 200 includes a processor that executes various arithmetic operations and controls. In addition to these, a member for supporting the face of the subject (jaw holder, forehead pad, etc.) and a lens unit for switching the target portion of OCT (for example, an attachment for anterior segment OCT) are provided. Further, the ophthalmologic imaging device 1 includes a pair of anterior ocular cameras 5A and 5B.

In the present specification, 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 SPLD (Simple Program) It means a circuit such as Programmable Logical Device) and FPGA (Field Programmable Gate Array). The processor realizes the function according to the embodiment by reading and executing a program stored in a storage circuit or a storage device, for example.

<Fundus camera unit 2>
The fundus camera unit 2 is provided with an optical system for photographing the anterior eye portion Ea and the fundus Ef. The acquired image is a front image such as an observation image or a photographed image. The observed image is obtained by taking a moving image using near infrared light. The captured image is a still image using flash light.

The fundus camera unit 2 includes an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the eye E to be inspected with illumination light. The photographing optical system 30 detects the return light of the illumination light from the eye E to be inspected. The measurement light from the OCT unit 100 is guided to the eye E to be inspected through the optical path in the fundus camera unit 2, and the return light is guided to the OCT unit 100 through the same optical path.

The observation light source 11 of the illumination optical system 10 outputs continuous light (observation illumination light) including a near-infrared component. The observation illumination light is reflected by the reflection mirror 12 having a curved reflecting surface, passes through the condenser lens 13, passes through the visible cut filter 14, and becomes near-infrared light. Further, the observation illumination light is once focused in the vicinity of the photographing light source 15, reflected by the mirror 16, and passes through the relay lenses 17, 18, the diaphragm 19, and the relay lens 20. Then, the observation illumination light is reflected at the peripheral portion of the perforated mirror 21 (the region around the perforated portion), passes through the dichroic mirror 46, is refracted by the objective lens 22, and is the eye to be inspected E (anterior eye portion Ea or). Illuminate the fundus Ef). The return light of the observation illumination light from the eye E to be inspected is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central region of the perforated mirror 21, and passes through the dichroic mirror 55. , It is reflected by the mirror 32 via the photographing focusing lens 31. Further, this return light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the image sensor 35 by the condenser lens 34. The image sensor 35 detects the return light at a predetermined frame rate. The focus of the photographing optical system 30 is adjusted with respect to the fundus Ef or the anterior segment of the eye.

The photographing light source 15 outputs flash light (photographing illumination light) including a visible component (and a near infrared component). The photographing illumination light irradiates the fundus Ef through the same path as the observation illumination light. The return light of the photographing illumination light from the eye E to be examined is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by the mirror 36, and is reflected by the condenser lens 37. An image is formed on the light receiving surface of the image sensor 38.

The LCD 39 displays a fixation target and a visual acuity measurement target. A part of the luminous flux (fixed-view luminous flux, etc.) output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, and passes through the photographing focusing lens 31 and the dichroic mirror 55, and the perforated mirror 21 Pass through the hole. The luminous flux that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef.

The change of the fixation position is realized by changing the display position of the bright spot or the like by the LCD 39. The display position of the bright spot or the like is controlled by the main control unit 211 described later. The main control unit 211 displays a bright spot or the like at a position on the screen of the LCD 39 corresponding to the fixation position set by a predetermined method. The method of setting the fixation position is performed by using, for example, the user interface 240 described later. Further, it can be configured to display a bright spot or the like at a predetermined position according to a shooting mode (macular mode, papilla mode, panoramic mode, etc.).

The alignment optical system 50 generates an alignment index used for alignment of the optical system with respect to the eye E to be inspected. The alignment light output from the LED 51 passes through the diaphragms 52 and 53 and the relay lens 54, is reflected by the dichroic mirror 55, and passes through the hole portion of the perforated mirror 21. The light that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46 and is projected onto the eye E to be inspected by the objective lens 22. The return light of the alignment light (corneal reflex light, fundus reflected light, etc.) is guided to the image sensor 35 through the same path as the return light of the observation illumination light. Manual alignment and auto alignment can be executed based on the received light image (alignment index image).

The focus optical system 60 generates a split index used for focus adjustment with respect to the eye E to be inspected. The focus optical system 60 is moved along the optical path (illumination optical path) of the illumination optical system 10 in conjunction with the movement of the photographing focusing lens 31 along the optical path (photographing optical path) of the photographing optical system 30. The reflection rod 67 is removable with respect to the illumination optical path. When adjusting the focus, the reflecting surface of the reflecting rod 67 is inclined and arranged in the illumination optical path. The focus light output from the LED 61 passes through the relay lens 62, is separated into two light beams by the split index plate 63, passes through the two-hole diaphragm 64, is reflected by the mirror 65, and is reflected by the condensing lens 66. Once imaged on the reflecting surface of, it is reflected. Further, the focus light passes through the relay lens 20, is reflected by the perforated mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef. The fundus reflected light of the focus light is guided to the image sensor 35 through the same path as the return light of the alignment light. Manual focusing or auto focusing can be executed based on the received light image (split index image).

The diopter correction lenses 70 and 71 can be selectively inserted into the photographing optical path between the perforated mirror 21 and the dichroic mirror 55. The diopter correction lens 70 is a plus lens (convex lens) for correcting high-intensity hyperopia. The diopter correction lens 71 is a minus lens (concave lens) for correcting intense myopia.

The dichroic mirror 46 synthesizes an optical path for fundus photography and an optical path for OCT. The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for fundus photography. The optical path for OCT is provided with a collimator lens unit 40, an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, a mirror 44, and a relay lens 45 in this order from the OCT unit 100 side.

The optical path length changing unit 41 is movable in the direction of the arrow shown in FIG. 1, and changes the optical path length for OCT. This change in the optical path length is used for correcting the optical path length according to the axial length and adjusting the interference state. The optical path length changing unit 41 includes a corner cube and a mechanism for moving the corner cube.

The optical scanner 42 is arranged at a position optically conjugate with the pupil of the eye E to be inspected. The optical scanner 42 deflects the measurement light LS passing through the optical path for OCT. The optical scanner 42 is, for example, a galvano scanner capable of two-dimensional scanning.

The OCT focusing lens 43 is moved along the optical path of the measurement light LS in order to adjust the focus of the optical system for OCT. The movement of the photographing focusing lens 31, the movement of the focus optical system 60, and the movement of the OCT focusing lens 43 can be controlled in a coordinated manner.

The ophthalmologic imaging device 1 includes an auxiliary lens unit 80 that can be arranged on the front side (E side of the eye to be inspected) of the objective lens 22. The auxiliary lens unit 80 includes, for example, a lens group having a positive refractive power. The auxiliary lens unit 80 is retracted from the optical path when OCT of the fundus Ef is performed, and is inserted into the optical path when OCT of the anterior segment Ea is performed. The movement of the auxiliary lens unit 80 (insertion / detachment with respect to the optical path) is performed electrically or manually.

<Anterior segment camera 5A and 5B>
The anterior segment cameras 5A and 5B are used to determine the relative position between the optical system of the ophthalmologic imaging apparatus 1 and the eye E to be inspected, as in the invention disclosed in Japanese Patent Application Laid-Open No. 2013-248376. The anterior segment cameras 5A and 5B are provided on the surface of the housing (fundus camera unit 2 and the like) in which the optical system is housed on the side to be inspected E. The ophthalmologic imaging apparatus 1 is three-dimensional between the optical system and the eye E to be inspected by analyzing two anterior segment images acquired substantially simultaneously from different directions by the anterior segment cameras 5A and 5B. Find the relative position. The analysis of the two anterior segment images may be the same as the analysis disclosed in Japanese Patent Application Laid-Open No. 2013-248376. Further, the number of front eye cameras may be any number of 2 or more.

In this example, the position of the eye E to be inspected (that is, the relative position between the eye E to be inspected and the optical system) is obtained by using two or more anterior eye cameras. Not limited to this. For example, the position of the eye E to be inspected can be determined by analyzing the front image of the eye E to be inspected (for example, the observation image of the anterior eye portion Ea). Alternatively, a means for projecting an index on the cornea of the eye E to be inspected can be provided, and the position of the eye E to be inspected can be obtained based on the projection position of the index (that is, the detection state of the corneal reflex luminous flux of this index).

<OCT unit 100>
As illustrated in FIG. 2, the OCT unit 100 is provided with an optical system for performing a swept source OCT. This optical system divides the light from the variable wavelength light source (wavelength sweep type light source) into the measurement light and the reference light, and superimposes the return light of the measurement light from the eye E to be examined and the reference light passing through the reference optical path. Includes an interfering optical system that generates interfering light and detects this interfering light. The detection result (detection signal) obtained by the interference optical system is sent to the arithmetic control unit 200.

The light source unit 101 includes, for example, a near-infrared wavelength tunable laser that changes the wavelength of emitted light at high speed. The light L0 output from the light source unit 101 is guided by the optical fiber 102 to the polarization controller 103, and its polarization state is adjusted. Further, the optical L0 is guided by the optical fiber 104 to the fiber coupler 105 and divided into the measurement optical LS and the reference optical LR.

The reference optical LR is guided by the optical fiber 110 to the collimator 111, converted into a parallel luminous flux, and guided to the corner cube 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with the optical path length of the measurement light LS. The dispersion compensating member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS. The corner cube 114 is movable in the incident direction of the reference light LR, thereby changing the optical path length of the reference light LR.

The reference light LR that has passed through the corner cube 114 is converted from a parallel light beam to a focused light beam by the collimator 116 via the dispersion compensating member 113 and the optical path length correction member 112, and is incident on the optical fiber 117. The reference light LR incident on the optical fiber 117 is guided by the polarization controller 118 to adjust its polarization state, is guided to the attenuator 120 by the optical fiber 119 to adjust the amount of light, and is guided to the fiber coupler 122 by the optical fiber 121. Be taken.

On the other hand, the measurement optical LS generated by the fiber coupler 105 is guided by the optical fiber 127 and converted into a parallel light beam by the collimator lens unit 40, and is converted into a parallel light beam by the collimator lens unit 40, and the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, and the mirror 44. The light is reflected by the dichroic mirror 46 via the relay lens 45, refracted by the objective lens 22, and incident on the eye E to be inspected. When OCT of the anterior segment Ea is performed, the measurement light LS refracted by the objective lens 22 is further refracted by the lens group in the auxiliary lens unit 80 and irradiated to the anterior segment Ea. The measurement light LS is scattered and reflected at various depth positions of the fundus Ef or the anterior segment Ea. The return light of the measurement light LS from the eye E to be inspected travels in the same direction as the outward path in the opposite direction, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

The fiber coupler 122 generates interference light by synthesizing (interfering with) the measurement light LS incidented through the optical fiber 128 and the reference light LR incidented via the optical fiber 121. The fiber coupler 122 generates a pair of interference light LCs by branching the interference light at a predetermined branching ratio (for example, 1: 1). The pair of interference light LCs are guided to the detector 125 through the optical fibers 123 and 124, respectively.

The detector 125 is, for example, a balanced photodiode. The balanced photodiode has a pair of photodetectors that detect each pair of interference light LCs, and outputs the difference between the detection results by these. The detector 125 sends this output (detection signal) to the DAQ (Data Acquisition System) 130.

A clock KC is supplied to the DAQ 130 from the light source unit 101. The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the tunable light source. The light source unit 101 optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then sets the clock KC based on the result of detecting the combined light. Generate. The DATA 130 samples the detection signal input from the detector 125 based on the clock KC. The DAQ 130 sends the sampling result of the detection signal from the detector 125 to the arithmetic control unit 200.

In this example, in order to change the length of the optical path length changing unit 41 for changing the length of the optical path (measurement optical path, measurement arm) of the measurement light LS and the length of the optical path (reference optical path, reference arm) of the reference light LR. Although both corner cubes 114 are provided, only one of the optical path length changing portion 41 and the corner cube 114 may be provided. It is also possible to change the difference between the measured optical path length and the reference optical path length by using an optical member other than these.

The polarization controllers 103 and 118 have known configurations. For example, the polarization controller 103 (118) includes one or more winding portions around which a part of the optical fiber is wound, and a rotating mechanism for rotating each winding portion. Alternatively, the polarization controller 103 (118) may include the following elements: a collimeter lens that converts the light once emitted from the optical fiber into a parallel light beam; a first 1 / sequentially arranged in the optical path of this parallel light beam. 4 wave plate (λ / 4 plate), 1/2 wave plate (λ / 2 plate) and 2nd 1/4 wave plate; parallel light beam passing through the 2nd 1/4 wave plate is directed toward the end of the optical fiber. Collimeter lens for focusing; a rotating mechanism that rotates the first 1/4 wave plate, 1/2 wave plate, and second 1/4 wave plate, respectively. Each of the polarization controllers 103 and 118 is controlled by the main control unit 211.

<Control system>
A configuration example of the control system of the ophthalmologic imaging apparatus 1 is shown in FIGS. 3A and 3B. The control unit 210, the image forming unit 220, and the data processing unit 230 are included in the arithmetic control unit 200.

<Control unit 210>
The control unit 210 executes various controls. The control unit 210 includes a main control unit 211 and a storage unit 212. The control unit 210 includes a processor.

<Main control unit 211>
The main control unit 211 controls each unit (including the elements shown in FIGS. 1 to 3B) of the ophthalmologic imaging apparatus 1. The photographing focusing drive unit 31A shown in FIG. 3A moves the photographing focusing lens 31, the OCT focusing drive unit 43A moves the OCT focusing lens 43, and the reference driving unit 114A moves the corner cube 114.

The optical system moving unit 150 moves at least a part of the optical system provided in the ophthalmologic imaging apparatus 1. As a typical example, the optical system moving unit 150 is configured to move the fundus camera unit 2 three-dimensionally. In this case, the optical system moving unit 150 includes, for example, one or more movable tables on which the fundus camera unit 2 is mounted, a lateral direction (horizontal direction, x direction), a vertical direction (y direction), and a front-rear direction (objective). Includes one or more actuators for moving the movable table in the optical axis direction, z direction).

<Memory unit 212>
The storage unit 212 stores various types of data. The data stored in the storage unit 212 includes an OCT image, an anterior eye portion image, a fundus image, and eye examination information. The eye test information includes subject information such as patient ID and name, left eye / right eye identification information, electronic medical record information, and the like.

<Image forming unit 220>
The image forming unit 220 forms an image based on the output from the DAQ 130 (sampling result of the detection signal). For example, the image forming unit 220 forms a reflection intensity profile for each A line by performing signal processing on the spectrum distribution based on the sampling result for each A line, as in the conventional swept source OCT (A scan, A). It is called a scanned image etc.). This signal processing includes noise removal (noise reduction), filter processing, FFT (Fast Fourier Transform), and the like. Further, the image forming unit 220 forms a cross-sectional image along the arrangement of the plurality of A lines by imaging a plurality of A line profiles corresponding to the plurality of A lines and arranging them along the scan line (B). (Called scan, B-scan image, etc.). The image forming unit 220 includes a processor.

<Data processing unit 230>
The data processing unit 230 executes various data processing. As a typical example, the data processing unit 230 processes images (fundus image, anterior segment image, etc.) acquired by the fundus camera unit 2, processes images acquired by the anterior segment cameras 5A and 5B, and an image forming unit. Processing of the image formed by 220 and the like are performed. These processes include at least one of various image processing and various analysis processing. For example, the data processing unit 230 creates three-dimensional image data (stack data, volume data, etc.) based on the OCT raster scan data, renders the three-dimensional image data, corrects the image, and executes image analysis based on the analysis application. The data processing unit 230 includes a processor.

The data processing unit 230 includes a first alignment processing unit 231, a second alignment processing unit 232, a focusing processing unit 233, and an optical path length adjusting processing unit 234. These processing units 231 to 234 execute processing for adjusting the imaging conditions to the displacement (rotation) of the eye E to be inspected due to the change in the fixation position. In this embodiment, after moving the fixation position, the position of the eye to be inspected is detected to perform rough alignment (coarse alignment), and then more precise alignment (alignment fine adjustment), focusing, and optical path length adjustment. To execute. The first alignment processing unit 231 executes a process related to coarse alignment, the second alignment processing unit 232 executes a process related to fine alignment, the focusing processing unit 233 executes a process related to focusing, and the optical path length adjustment processing unit 234. Performs processing related to optical path length adjustment.

In a typical example of the present embodiment, after the fixation light flux corresponding to the changed fixation position is projected onto the eye E to be inspected, the pair of anterior eye cameras 5A and 5B photograph the eye E to be inspected substantially at the same time. .. The pair of anterior segment images (which may be multiple pairs of anterior segment images acquired in chronological order) acquired by the pair of anterior segment cameras 5A and 5B are displaced as the fixation position is changed. It is used to determine the position (three-dimensional position) of optometry E. The optical system is moved to a position corresponding to the obtained three-dimensional position of the eye E to be inspected (coarse alignment), and then fine alignment, focusing, and optical path length adjustment are performed.

<First alignment processing unit 231>
The first alignment processing unit 231 executes data processing related to coarse alignment. For example, the first alignment processing unit 231 analyzes the pair of anterior eye images acquired substantially at the same time by the pair of anterior eye cameras 5A and 5B, so that the eye E to be inspected after the fixation position is changed. The position (for example, the position relative to the ophthalmologic imaging device 1) is obtained. This process includes, for example, as described in Japanese Patent Application Laid-Open No. 2013-248376, an arithmetic process using a trigonometry based on the positional relationship between the pair of anterior eye cameras 5A and 5B and the eye E to be inspected.

The main control unit 211 moves the optical system based on the position of the eye E to be inspected obtained by the first alignment processing unit 231 so that the optical system (for example, the fundus camera unit 2) and the eye E to be inspected have a predetermined positional relationship. The unit 150 is controlled. Here, the predetermined positional relationship is a positional relationship in which the image of the eye E to be inspected can be photographed or examined using the optical system. As a typical example, when the first alignment processing unit 231 obtains the three-dimensional position (x-coordinate, y-coordinate, z-coordinate) of the eye to be inspected E, the x-coordinate and y-coordinate of the optical axis of the objective lens 22 are the eye to be inspected E. The position where the x-coordinate and the y-coordinate of the objective lens 22 (front lens surface) and the z-coordinate of the eye to be inspected E (corneal surface) are equal to a predetermined distance (working distance) is equal to the x-coordinate and the y-coordinate of the above. , Set as the destination of the optical system. The same process can be executed when any one or more of these three-dimensional coordinates are referred to.

<Second alignment processing unit 232>
The second alignment processing unit 232 executes data processing related to alignment fine adjustment executed after the rough alignment. Alignment fine adjustment is performed with higher accuracy than coarse alignment. Therefore, the detection accuracy of the position of the eye E to be inspected in the fine alignment adjustment is set to be higher than the position detection accuracy in the coarse alignment. That is, the position detection in the fine alignment adjustment is executed with the same accuracy as the position detection in the coarse alignment, or is executed with a higher accuracy.

The position detection in the coarse alignment and the position detection in the fine alignment adjustment are executed by using the same element (means) or by using different elements. When the same element is used for both alignments, the detection accuracy of this element may be switched. For example, it is possible to configure and control the position detection for coarse alignment to be executed with the first accuracy and the position detection for fine alignment to be executed with a second accuracy higher than the first accuracy. It is possible. When the same element is used for both alignments, the first alignment processing unit 231 and the second alignment processing unit 232 may be the same element (processor or the like).

As a typical example, position detection in coarse alignment includes one of the following elements: (1-1) Two or more imaging units (eg, a pair) for imaging the eye E to be inspected from different directions. Front eye camera 5A and 5B); (1-2) Front image acquisition unit for photographing the eye E to be inspected from the front (example: illumination optical system 10 and photographing optical system 30 for acquiring an observation image); ( 1-3) An index optical system that projects an index light beam onto the cortex of the eye E to be inspected and detects the reflected light beam from the corneum. The combination of each of (1-1), (1-2) and (1-3) with the first alignment processing unit 231 is an example of the first position detection unit. In this embodiment, (1-1) is applied. (1-2) and (1-3) will be described later.

Also, as a typical example, position detection in fine alignment includes one of the following elements: (2-1) Two or more imaging units (eg) for photographing the eye E to be inspected from different directions. : A pair of anterior eye cameras 5A and 5B); (2-2) Means for projecting an alignment index on the eye E to be inspected (eg, alignment optical system 50), and taking an image of the eye E on which the alignment index is projected. Means (eg, imaging optical system 30). Here, (2-1) is the same element as (1-1). Further, (2-2) is an element different from any of (1-1), (1-2) and (1-3). The combination of each of (2-1) and (2-2) with the second alignment processing unit 232 is an example of the second position detection unit.

In this embodiment, (2-1) or (2-2) is applied. When (2-1) is applied, the second alignment processing unit 232 is combined with the pair of optometry cameras 5A and 5B, similarly to the first alignment processing unit 231 when (1-1) is applied. The position (three-dimensional position) of the eye E to be inspected is obtained by executing an arithmetic process using the trigonometry based on the positional relationship with the eye E to be inspected. On the other hand, when (2-2) is applied, an alignment index is projected onto the eye E to be inspected, and the return light is detected by the image sensor 35, as in general auto-alignment. The second alignment processing unit 232 extracts the alignment index image from the output signal from the image sensor 35, and calculates the displacement of the alignment index image with respect to a predetermined alignment mark (for example, a parenthesis mark arranged at the center of the frame). The calculated displacement is used as the position of the eye E to be inspected.

After the optical system moving unit 150 is controlled based on the position of the eye to be inspected E determined by the first alignment processing unit 231, the second alignment processing unit 232 detects the position of the eye to be inspected E. The main control unit 211 controls the optical system moving unit 150 based on the position detected by the second alignment processing unit 232. As a result, the position of the optical system is adjusted so that the optical system and the eye E to be inspected have the above-mentioned predetermined positional relationship.

<Focus processing unit 233>
The focusing processing unit 233 executes data processing related to focusing. The ophthalmologic imaging apparatus 1 according to the present embodiment includes a focusing function in a fundus camera (fundus imaging) and a focusing function in OCT. Focusing in the fundus camera is, for example, a shooting focusing lens 31 of the shooting optical system 30, a shooting focusing drive unit 31A for moving the shooting focusing lens 31, and a main control unit that controls the shooting focusing drive unit 31A. It is executed by the configuration including 211 and the focusing processing unit 233. Further, focusing in OCT includes, for example, an OCT focusing lens 43 in the measurement optical path, an OCT focusing drive unit 43A for moving the OCT focusing lens 43, and a main control unit 211 that controls the OCT focusing drive unit 43A. And the focusing processing unit 233 are included in the configuration. Both focusings may be performed in a coordinated manner or independently of each other.

In focusing, first, a process for grasping the current focus state is executed. This process is performed, for example, using a split index. That is, as is generally performed, the focusing processing unit 233 extracts a pair of split index images by analyzing the observation image of the fundus Ef on which the split index is projected, and the pair of split indexes. Calculate the relative deviation of. The calculated shift (shift direction, shift amount) reflects the current focus state. The main control unit 211 controls the imaging focusing drive unit 31A and the OCT focusing drive unit 43A based on the calculated deviation.

In another typical example, OCT can be used to determine the current focus state. The process using OCT is executed, for example, as follows. First, OCT is repeatedly performed on substantially the same cross section of the fundus Ef (live scan). As a result, a moving image (OCT moving image) of this cross section is taken. The frame rate of the OCT moving image corresponds to the repetition frequency of OCT. As the first method, manual focusing is possible by displaying the OCT moving image on the display unit 241.

As a second method, auto-focusing is possible by performing the following processing by the focusing processing unit 233. The focusing processing unit 233 analyzes the pixel value (luminance value) of the still image constituting the OCT moving image to identify a region with high image quality (high image quality region), and further, the depth direction (z direction) of the frame. The current focal position can be specified based on the position (z coordinate) of the high image quality region in. If the tissue of the fundus Ef to be focused on (fundus surface, retinal pigment epithelial layer, ganglion cell layer, nerve fiber layer, choroid, etc.) has already been determined, the focusing processing unit 233 will be applied to the tissue in the still image. Identify the corresponding area (target area). Alternatively, the target area may be specified by the user. The focusing processing unit 233 obtains the position (z coordinate) of the target region in the depth direction (z direction) of the frame. The main control unit 211 generates a control signal for moving the current focal position of the optical system for OCT to a position corresponding to the target region, and sends the control signal to the OCT focusing drive unit 43A. Thereby, the focal position of the measurement light LS can be adjusted to the target region. The main control unit 211 can execute the control of the imaging focusing drive unit 31A in cooperation with the control of the OCT focusing drive unit 43A.

Another example of Focusing using OCT will be described. In this example, focusing is performed based on the measurement sensitivity (interference sensitivity) of OCT. For example, it is possible to determine the position of the OCT focusing lens 43 that maximizes the interference intensity while monitoring the intensity (interference intensity) of the interference signal obtained by OCT. The main control unit 211 arranges the OCT focusing lens 43 at this position. Further, the main control unit 211 moves the photographing focusing lens 31 to a position corresponding to the position of the OCT focusing lens 43.

<Optical path length adjustment processing unit 234>
As described above, in the ophthalmologic imaging apparatus 1 according to the present embodiment, the optical path length changing unit 41 for changing the optical path length of the measurement light LS, the corner cube 114 for changing the optical path length of the reference light LR, and the reference. It is provided with a drive unit 114A. Generally, at least one of an element for changing the optical path length of the measurement light and an element for changing the optical path length of the reference light are provided. In other words, an element for changing the difference between the length of the measurement optical path and the length of the reference optical path is provided.

The optical path length adjustment processing unit 234 executes a process for calculating the deviation of the optical path length of the measurement optical path and / or the reference optical path. The deviation of the optical path length is expressed as, for example, a displacement of the measurement light LS with respect to a predetermined position (reference position) in the optical axis direction (z direction) of the optical path. This reference position is typically set at the z position that passes through or near the center of the OCT imaging range. The main control unit 211 controls the optical path length changing unit 41 and / or the reference driving unit 114A so as to cancel the deviation calculated by the optical path length adjusting processing unit 234.

As described above, in the optical path length difference adjustment, the optical path length changing unit 41 and / or the reference driving unit 114A is drawn so that the predetermined portion (reference portion) of the eye E to be inspected is drawn at a predetermined z position in the frame of the OCT image. Is controlled. Thereby, the optical path length difference between the measurement optical path and the reference optical path is adjusted. As the reference portion, a portion exhibiting a characteristic brightness in the OCT image (or a portion exhibiting a characteristic reflection intensity in the reflection intensity profile) is set in advance. As a specific example, in the OCT measurement of the fundus Ef, the retinal pigment epithelial layer can be set as a reference, and in the OCT measurement of the anterior segment, the corneal surface can be set as a reference. The automatic process of searching for a suitable optical path length difference in this way is called auto Z.

The optical path length difference adjustment is not limited to the auto Z. For example, automatic processing for maintaining a suitable image drawing position achieved by Auto Z can be applied. Such a process is called Z-lock. In the Z lock, for example, the optical path length changing unit 41 is controlled so that the state in which the reference portion for adjusting the optical path length difference is drawn at a predetermined z position in the frame is maintained.

<Polarization adjustment processing unit 235>
The polarization characteristics of the fundus Ef differ from site to site. For example, the polarization characteristics of the optic nerve head (and its vicinity) and the polarization characteristics of the macula (and its vicinity) are different. Therefore, in order to improve the image quality of the OCT image, it is desirable to control the polarization state according to the imaged portion. In this example, the polarization state of the reference light LR is controlled by the polarization controller 118, but a polarization controller for controlling the polarization state of the measurement light LS may be arranged in the measurement optical path. Further, the polarization controller may be arranged in both the reference optical path and the measurement optical path.

The main control unit 211 repeatedly executes the OCT scan while controlling the polarization controller 118. The polarization adjustment processing unit 235 analyzes the sequentially acquired OCT images and calculates the evaluation value of the image quality. The image quality evaluation value may be any image quality parameter such as contrast. The main control unit 211 controls the polarization controller 118 based on the image quality evaluation values calculated sequentially. That is, the main control unit 211 searches for the polarization state in which the image quality evaluation value is optimized by feeding back the sequentially calculated image quality evaluation value to the control of the polarization controller 118.

<User interface 240>
The user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes a display device 3. The operation unit 242 includes various operation devices and input devices. The user interface 240 may include a device such as a touch panel in which a display function and an operation function are integrated. It is also possible to build embodiments that do not include at least a portion of the user interface 240. For example, the display device may be an external device connected to the ophthalmologic imaging device.

<motion>
The operation of the ophthalmologic imaging apparatus 1 will be described. An example of the operation is shown in FIG.

(S1: Start of macular mode)
First, preparations for shooting are made. The examiner activates the ophthalmologic imaging device 1 and selects a desired imaging mode. In this example, the case where the macular mode and the papillary mode are applied in this order will be described. The macula mode is an imaging mode for photographing the macula and its peripheral region (OCT scan), and the papillary mode is an imaging mode for photographing the optic nerve papilla and its peripheral region. The subject's face is fixed by a chin rest and a forehead pad.

Upon receiving a predetermined operation, the main control unit 211 starts the process related to the macula mode. The main control unit 211 controls the LCD 39 so as to display a bright spot at a predetermined position according to the macula mode. As a result, a fixed-point luminous flux corresponding to the fixed-point position for photographing the macula and its peripheral region is projected onto the eye E to be inspected.

(S2: Execution of auto alignment)
The main control unit 211 executes auto-alignment. Auto-alignment is performed in the same manner as before by using a pair of anterior segment cameras 5A and 5B or an alignment index.

(S3: Optimization of OCT conditions)
Next, the ophthalmologic imaging apparatus 1 executes a process for optimizing the OCT condition. This optimization process includes, for example, focusing, optical path length adjustment, and polarization adjustment. Focusing and optical path length adjustment are performed as described above. Further, the optimization process may include adjustment of the amount of light (for example, control of the attenuator 120) and the like.

(S4: OCT scan of macula)
After the optimization process is completed, the main control unit 211 executes an OCT scan (for example, a raster scan) of the macula and its surrounding area by controlling the OCT unit 100, the optical scanner 42, and the like. The image forming unit 220 forms a plurality of B scan images based on the data collected by the raster scan. The data processing unit 230 creates three-dimensional image data based on a plurality of B-scan images.

(S5: Switch to nipple mode)
After the OCT scan of the macula is complete, the macula mode ends. The main control unit 211 causes the display unit 241 to display a graphical user interface (GUI) including an icon of the next shooting mode (shooting part, etc.). The examiner selects a desired shooting mode. In this example, the papilla mode is selected. When another shooting mode is selected, processing according to the shooting mode is executed. If the imaging mode is not selected for a certain period of time, the imaging of the subject or the subject's eyes is completed.

(S6: Change of fixation position)
When the teat mode is selected, the main control unit 211 controls the LCD 39 to display a bright spot at a predetermined position according to the teat mode. As a result, a luminous flux corresponding to the fixation position for photographing the optic nerve head and its peripheral region is projected onto the eye E to be inspected.

(S7: Capture of a pair of anterior segment images)
The main control unit 211 captures a pair of anterior segment images acquired substantially simultaneously by the anterior segment cameras 5A and 5B after the fixation position is changed. The main control unit 211 sends the captured pair of anterior segment images to the data processing unit 230.

(S8: Detection of the position of the eye to be inspected)
The first alignment processing unit 231 obtains the position of the eye E to be inspected after the fixation position is changed by analyzing the pair of anterior eye image input from the main control unit 211. In this analysis process, for example, a process of extracting the pupil region from each anterior segment image, a process of finding the center of gravity or the center of the pupil region, and a process of finding the obtained positions of the pair of pupil center of gravity and the like are used for the eye E3. Includes processing to calculate the dimensional position.

(S9: Coarse alignment)
The main control unit 211 controls the optical system moving unit 150 based on the three-dimensional position of the eye E to be inspected detected in step S8 so that the fundus camera unit 2 and the eye E to be inspected have a predetermined positional relationship. As described above, in this predetermined positional relationship, the x-coordinate and y-coordinate of the optical axis of the objective lens 22 coincide with the x-coordinate and y-coordinate of the eye E to be inspected, respectively, and the objective lens 22 (front lens surface) This is a positional relationship in which the difference between the z-coordinate and the z-coordinate of the eye E (corneal surface) to be inspected is equal to a predetermined distance (working distance).

(S10: Fine alignment adjustment)
After the rough alignment is completed, the main control unit 211 and the second alignment processing unit 232 execute the fine alignment adjustment as described above.

(S11: Focusing)
After the alignment fine adjustment is completed, the main control unit 211 and the focusing processing unit 233 execute focusing as described above.

(S12: Optical path length adjustment)
After the focusing is completed, the main control unit 211 and the optical path length adjustment processing unit 234 execute the optical path length adjustment as described above.

(S13: Polarization adjustment)
After the completion of the optical path length adjustment, the main control unit 211 and the polarization adjustment processing unit 235 execute the optical path length adjustment in the manner described above.

(S14: OCT scan of nipple)
After the processing (optimization processing) of steps S10 to S13 is completed, the main control unit 211 performs an OCT scan (for example, a raster scan) of the optic nerve head and its peripheral region by controlling the OCT unit 100, the optical scanner 42, and the like. Execute. The image forming unit 220 forms a plurality of B scan images based on the data collected by the raster scan. The data processing unit 230 creates three-dimensional image data based on a plurality of B-scan images.

When performing an OCT scan of another site, the same process as in steps S5 to S14 is repeated. In addition, if necessary, the companion eye of the eye to be inspected E is photographed. When the photographing of the subject is completed, the main control unit 211 stores the acquired images and data in a medical image archiving device or the like (not shown). This is the end of the process related to this example.

<Modification example>
Some modifications of the above embodiment will be described.

(About coarse alignment)
In the above embodiment, as shown in (1-1) above, coarse alignment is performed using two or more imaging units (eg, a pair of anterior eye cameras 5A and 5B) for photographing the eye to be inspected from different directions. The configuration to execute is explained. Hereinafter, a case where the following configuration is applied will be described: (1-2) Front image acquisition unit for photographing the eye E to be inspected from the front (example: illumination optical system 10 for acquiring an observation image and photographing optics). System 30); (1-3) An index optical system that projects an index light beam onto the cornea of the eye E to be inspected and detects a reflected light flux from the corneum.

(1-2) When the front image acquisition unit for photographing the eye E to be inspected from the front is applied, for example, the process of specifying the pupil region in the observation image of the anterior eye portion Ea and the center of gravity or the center thereof are specified. The process, the process of calculating the displacement between the position of the center of gravity and the center of the frame (the position of the optical axis of the photographing optical system 30), and the process of controlling the optical system moving unit 150 so as to cancel this displacement, the fundus camera unit 2, etc. The process of moving the optics is executed. In this example, the positions in the x direction and the y direction are referred to.

(1-3) When an index optical system that projects an index luminous flux onto the cornea of the eye E to be inspected and detects a reflected luminous flux from the corneum is applied, for example, the index is directed to the corneum from a direction different from the optical axis of the photographing optical system 30. A projection system for projecting a luminous flux and a light receiving system arranged in a direction symmetrical to the projection system with respect to the optical axis of the photographing optical system 30 are provided. The projection system includes, for example, a light source, a condenser lens, and the like. The image of the index luminous flux projected on the cornea is, for example, a bright spot image or a ring image. The light receiving system includes, for example, an imaging lens, an image sensor, and the like, and detects the reflected luminous flux of the index luminous flux projected on the cornea by the projection system. The output signal from the image sensor is input to the main control unit 211. The first alignment processing unit 231 identifies the pixel of the image sensor that has detected the reflected luminous flux of the index luminous flux based on the output signal from the image sensor, and determines the position of the eye E to be inspected based on the position of this pixel. When a ring image or the like is projected on the cornea, the position of a pixel corresponding to the center of gravity or the center of the ring image detected by the image sensor can be obtained, and the position of the eye E to be inspected can be obtained based on the position of this pixel. it can.

Any two or more of (1-1), (1-2) and (1-3) can be combined. Further, rough alignment may be performed using a configuration other than these. It is also possible to combine any two or more of (1-1), (1-2), (1-3) and other configurations.

Other techniques for coarse alignment (and / or fine alignment) will be described. In this example, the fundus camera unit 2 (illumination optical system 10 and photographing optical system 30) is used to acquire a live image of the anterior segment Ea, and the first alignment processing unit 231 measures the size (area,) of the pupil region in each frame. The position of the fundus camera unit 2 is changed stepwise or continuously while monitoring (diameter, etc.). As a result, the size of the pupillary region changes over time. It is considered that the size of the pupil region is maximized when the optical axis of the photographing optical system 30 coincides with the center of gravity (center) of the pupil. Therefore, rough alignment can be performed by searching for the position of the fundus camera unit 2 that maximizes the size of the pupil region by using the main control unit 211, the first alignment processing unit 231 and the like.

Further other methods will be described. In this example, a pair of anterior segment cameras 5A and 5B are used to acquire a live image of the anterior segment Ea. That is, the pair of anterior segment cameras 5A and 5B repeatedly perform substantially simultaneous imaging at predetermined time intervals (frame rates). The pair of frames (anterior segment images) acquired substantially at the same time are sequentially sent to the first alignment processing unit 231. The first alignment processing unit 231 calculates the size (area, diameter, etc.) of the pupil region in each of the pair of frames. The relationship between the sizes of the pupil regions in the pair of frames is affected by the positional relationship between the pair of anterior ocular cameras 5A and 5B. For example, when a pair of anterior segment cameras 5A and 5B are arranged at positions (directions) symmetrical to each other with respect to the optical axis of the photographing optical system 30, the optical axis of the photographing optical system 30 is the center of gravity of the pupil. When is matched, the size of the pupillary region in the pair of frames is considered to be equal. Therefore, rough alignment can be performed by using the main control unit 211, the first alignment processing unit 231 and the like to search for the position of the fundus camera unit 2 such that the sizes of the pupil regions in the pair of frames are equal.

(About panoramic shooting)
The panoramic shooting is a shooting mode in which a plurality of regions of the fundus Ef are sequentially shot, and a plurality of acquired images are combined to construct a wide area image (panoramic image). It is possible to apply the configuration and operation of the ophthalmologic imaging apparatus 1 to panoramic imaging. In panoramic photography, first, an OCT scan of the first region of the fundus Ef is performed while projecting a fixed-point luminous flux corresponding to the first fixed-view position. After the completion of the OCT scan of the first region, the fixation light flux corresponding to the second fixation position is projected, rough alignment, fine alignment adjustment, focusing, optical path length adjustment, etc. are executed, and the OCT scan of the second region is executed. Will be done. Similarly, after the imaging of the m + 1 region is completed, the fixation light flux corresponding to the m + 1 fixation position is projected, rough alignment, fine alignment adjustment, focusing, optical path length adjustment, etc. are executed, and the OCT scan of the m + 1 region is performed. Is executed. This series of processes is repeated until the OCT scan of the plurality of areas is completed. The OCT scan of each region is, for example, a raster scan. The data processing unit 230 forms a plurality of three-dimensional images from a plurality of OCT scan data corresponding to the plurality of regions, and synthesizes these three-dimensional images to represent a single three-dimensional range including the plurality of regions. Form an image.

(About other modality)
It is possible to apply the same processing as described above in fundus photography using SLO. For example, in panoramic photography by SLO, an SLO scan of a first region of the fundus Ef is executed while projecting a fixed-point luminous flux corresponding to the first fixed-view position. After the completion of the SLO scan of the first region, the fixation light flux corresponding to the second fixation position is projected, rough alignment, fine alignment adjustment, focusing and the like are executed, and the SLO scan of the second region is executed. Similarly, after the shooting of the m + 1 region is completed, the fixation light flux corresponding to the m + 1 fixation position is projected, coarse alignment, fine alignment, focusing, etc. are executed, and the SLO scan of the m + 1 region is executed. .. This series of processes is repeated until the SLO scan of the plurality of areas is completed. The SLO scan of each area is, for example, a raster scan. The data processing unit 230 forms a single SLO image representing a range including the plurality of regions by synthesizing a plurality of SLO images corresponding to the plurality of regions.

The SLO scan can be performed while changing the fixation position or while performing coarse alignment, fine alignment adjustment, focusing, or the like. For example, while repeatedly executing an SLO scan (raster scan or the like), it is possible to change the fixation position, perform coarse alignment, finely adjust the alignment, focus, and the like. It is also possible to perform an SLO scan while continuously moving the fixation position.

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

The ophthalmologic imaging apparatus of the embodiment includes an image acquisition unit, an optometry optical system, an optical system moving unit, a first position detection unit, and a control unit.

The image acquisition unit includes an optical system that projects light onto the eye to be inspected and detects the return light, and acquires an image of the eye to be inspected from the detection results obtained by this optical system. In the above embodiment, this optical system includes an element included in the OCT unit 100 and an element forming a measurement optical path in the fundus camera unit 2. The image acquisition unit includes an image forming unit 200 in addition to this optical system. The image acquisition unit is configured to be capable of executing at least one of OCT and SLO, for example.

The fixation optical system projects an fixation light beam corresponding to a preset fixation position onto the eye to be inspected. In the above embodiment, the fixation optical system includes an LCD 39 and an element that guides the light flux output from the LCD 39 to the eye to be inspected.

The optical system moving unit has a configuration for moving the optical system in the image acquisition unit, and the optical system moving unit 150 in the above embodiment corresponds to this.

The first position detection unit detects the position of the eye to be inspected. In the above embodiment, the pair of anterior segment cameras 5A and 5B and the first alignment processing unit 231 correspond to the first position detection unit. Further, in the above modification, the combination of the front image acquisition unit for photographing the eye to be inspected from the front and the first alignment processing unit 231 corresponds to the first position detection unit. Alternatively, the combination of the index optical system that projects the index light beam onto the cornea of the eye to be inspected and detects the reflected light flux from the cornea and the first alignment processing unit 231 corresponds to the first position detection unit.

After the fixation optical system projects the fixation light flux corresponding to the new fixation position onto the eye to be inspected, the first position detection unit detects the position of the eye to be inspected. That is, the first position detection unit detects the position of the eye to be inspected after the fixation position is changed. The control unit controls the optical system moving unit based on the position of the eye to be inspected detected after the fixation position is changed. In the above embodiment, the main control unit 211 corresponds to the control unit.

According to the ophthalmologic imaging apparatus configured as described above, the position of the eye to be inspected after the fixation position is changed can be actually detected, and the optical system can be aligned according to the detection result. Therefore, it is possible to accurately adjust the imaging conditions according to the change in the fixation position.

In the embodiment having the OCT function, the optical path length can be adjusted after the above alignment. To that end, the optics include interfering optics and optical scanners for performing OCT. The interference optical system projects the measurement light onto the eye to be inspected, superimposes the return light and the reference light to generate the interference light, and detects the interference light. In the above embodiment, the elements forming the measurement optical path, the reference optical path, and the optical path of the interference light correspond to the interference optical system. The optical scanner is arranged in the optical path of the measurement light, and the optical scanner 42 in the above embodiment corresponds to this.

Further, the image acquisition unit includes a cross-sectional image forming unit that forms a cross-sectional image based on the data collected by the interference optical system and the optical scanner. The image forming unit 220 (and the data processing unit 230) in the above embodiment corresponds to the cross-sectional image forming unit. Further, an optical path length changing unit for changing the optical path length of at least one of the measurement light and the reference light is provided. In the above embodiment, the optical path length changing unit 41 and the combination of the corner cube 114 and the reference drive unit 114A correspond to the optical path length changing unit. The control unit can execute control of the optical path length changing unit (optical path length adjustment) in addition to control (alignment) of the optical system moving unit.

The optical path length adjustment is performed by, for example, Auto Z. Therefore, after the control (alignment) of the moving part of the optical system, data is collected by the interfering optical system and the optical scanner (that is, an OCT scan is performed). The cross-sectional image forming unit forms a cross-sectional image based on the collected data. Further, the first analysis unit analyzes this cross-sectional image to obtain the displacement of the eye to be inspected with respect to a predetermined position in the optical axis direction of the optical path of the measurement light. In the above embodiment, the optical path length adjustment processing unit 234 corresponds to the first analysis unit. The control unit executes control (optical path length adjustment) of the optical path length changing unit so as to cancel the displacement obtained by the first analysis unit.

According to such a configuration, in addition to the alignment accompanying the change of the fixation position, the optical path length adjustment of the interference optical system for OCT can be automatically executed, so that the imaging with the change of the fixation position can be easily performed. Moreover, it becomes possible to carry out smoothly.

In the embodiment having the OCT function, the polarization adjustment can be performed after the above alignment. Therefore, a polarization state changing unit for changing the polarization state of at least one of the measurement light and the reference light is provided. The polarization controller 118 in the above embodiment corresponds to the polarization adjustment processing unit. The control unit can execute control of the optical path length changing unit in addition to controlling the optical system moving unit.

According to such a configuration, in addition to the alignment accompanying the change of the fixation position, the polarization adjustment for OCT can be automatically executed, so that the imaging with the change of the fixation position can be easily and smoothly performed. Is possible.

In an embodiment having an OCT function, an SLO function, or the like, focusing can be performed after the above alignment. To that end, the optics include a focusing lens for changing its focal position. In the above embodiment, the OCT focusing lens 43 (and the photographing focusing lens 31) corresponds to the focusing lens. Further, a focusing lens moving portion for moving the focusing lens is provided. In the above embodiment, the OCT focusing drive unit 43A (and the photographing focusing drive unit 31A) corresponds to the focusing lens moving unit. The control unit executes control (focusing) of the focusing lens moving unit in addition to control (alignment) of the optical system moving unit.

According to such a configuration, focusing can be automatically executed in addition to the alignment accompanying the change of the fixation position, so that the imaging accompanied by the change of the fixation position can be easily and smoothly performed.

The first position detection unit has an arbitrary configuration. For example, the first position detection unit may include two or more photographing units and a second analysis unit. The two or more imaging units photograph the eye to be inspected from different directions, and the pair of anterior eye camera 5A and 5B in the above embodiment correspond to this. The second analysis unit is configured to determine the position of the eye to be inspected by analyzing two or more images acquired substantially at the same time by the two or more imaging units, and the first alignment processing unit 231 in the above embodiment is the same. Corresponds to. The control unit controls (that is, aligns) the optical system moving unit based on the position of the eye to be inspected determined by the second analysis unit so that the optical system and the eye to be inspected have a predetermined positional relationship.

Another example of the first position detection unit includes a front image acquisition unit and a third analysis unit. The front image acquisition unit captures the eye to be inspected from the front. In the above embodiment, the illumination optical system 10 and the photographing optical system 30 correspond to the front image acquisition unit. The third analysis unit obtains the position of the eye to be inspected by analyzing the front image acquired by the front image acquisition unit. In the above embodiment, the first alignment processing unit 231 corresponds to the third analysis unit. The control unit controls (that is, aligns) the optical system moving unit based on the position of the eye to be inspected determined by the third analysis unit so that the optical system and the eye to be inspected have a predetermined positional relationship.

Yet another example of the first position detection unit includes an index optical system and a fourth analysis unit. The index optical system projects an index light flux onto the cornea of the eye to be inspected and detects the reflected light flux from the cornea. The index luminous flux forms, for example, a bright spot image or a ring image on the cornea. The fourth analysis unit obtains the position of the eye to be inspected by analyzing the detection result obtained by the index optical system. In the above embodiment, the first alignment processing unit 231 corresponds to the fourth analysis unit. The control unit controls (that is, aligns) the optical system moving unit based on the position of the eye to be inspected determined by the fourth analysis unit so that the optical system and the eye to be inspected have a predetermined positional relationship.

The alignment state achieved by the above alignment (coarse alignment) can be fine-tuned. Therefore, a second position detection unit capable of detecting the position of the eye to be inspected with an accuracy higher than the detection accuracy by the first position detection unit is provided. The second position detection unit may be configured to include elements different from those of the first position detection unit, or may be configured to include the same elements as the first position detection unit. In the above embodiment, the combination of the pair of anterior segment cameras 5A and 5B (or the alignment optical system 50) and the second alignment processing unit 232 corresponds to the second position detection unit. After the optical system moving unit is controlled based on the position of the eye to be inspected detected by the first position detection unit, the second position detection unit detects the position of the eye to be inspected. That is, the position of the eye to be inspected after the rough alignment is executed is detected by the second position detection unit. The control unit controls the optical system moving unit based on the position of the eye to be inspected detected by the second position detection unit (that is, finely adjusts the alignment).

According to such a configuration, the alignment state can be finely adjusted after the rough alignment due to the change of the fixation position, so that the imaging with the change of the fixation position can be easily and smoothly performed.

The configuration and operation of the elements included in the ophthalmologic imaging apparatus according to the embodiment are not limited to the items illustrated above.

The embodiments described above are merely examples of the present invention. A person who intends to carry out the present invention can arbitrarily make modifications (omission, substitution, addition, etc.) within the scope of the gist of the present invention.

1 Ophthalmology imaging device 2 Fundus camera unit 5A, 5B Front eye camera 10 Illumination optical system 30 Imaging optical system 39 LCD
100 OCT unit 150 Optical system moving unit 211 Main control unit 220 Image forming unit 231 First alignment processing unit

Claims (6)

An image acquisition unit that includes an optical system that projects light onto the eye to be inspected and detects the return light, and acquires an image of the eye to be inspected from the detection results obtained by the optical system.
An fixation optical system that projects a fixation light flux corresponding to a preset fixation position onto the eye to be inspected, and an fixation optical system.
An optical system moving unit for moving the optical system and
A first image of the anterior segment of the eye to be inspected is acquired, and a displacement at a relative position between the optical axis of the optical system and the center of the pupil of the eye to be inspected is detected as the position of the eye to be inspected based on the live image. 1 position detector and
Equipped with a control unit
After the fixation optical system projects an fixation beam corresponding to a new fixation position onto the eye to be inspected, the first position detection unit acquires a live image of the anterior eye portion and obtains a live image of the anterior eye portion, and the pupil in the live image. The position of the eye to be inspected is detected based on the size of the area.
The control unit is an ophthalmologic imaging apparatus characterized in that it controls the optical system moving unit based on the position. The first position detection unit is
A pair of anterior segment cameras for capturing the anterior segment from different directions and acquiring a pair of live images.
Includes a processing unit that calculates the size of each of the pair of pupil regions in the pair of frames acquired substantially simultaneously by the pair of anterior segment cameras.
The ophthalmologic imaging apparatus according to claim 1, wherein the control unit controls the optical system moving unit so that the sizes of the pair of pupil regions calculated by the processing unit have a predetermined relationship. The pair of anterior segment cameras are arranged symmetrically with respect to the optical axis of the optical system of the image acquisition unit.
The ophthalmologic imaging apparatus according to claim 2, wherein the control unit controls the optical system moving unit so that the sizes of the pair of pupil regions calculated by the processing unit are equal to each other. The first position detection unit is
A front image acquisition unit for acquiring a live image by photographing the anterior eye portion from the front direction,
Including a processing unit for calculating the size of the pupil region in the frame acquired by the front image acquisition unit.
The ophthalmologic imaging apparatus according to claim 1, wherein the control unit controls the optical system moving unit based on the size of the pupil region calculated by the processing unit. The front image acquisition unit includes a photographing optical system having a common optical axis with the optical system of the image acquisition unit.
The processing unit calculates the size of the pupil region in the frame of the live image acquired by the photographing optical system, and calculates the size of the pupil region.
The ophthalmologic imaging apparatus according to claim 4, wherein the control unit controls the optical system moving unit so that the size of the pupil region calculated by the processing unit is maximized. A second position detection unit capable of detecting the position of the eye to be inspected with an accuracy higher than the detection accuracy of the first position detection unit is further provided.
After the optical system moving unit is controlled based on the position detected by the first position detecting unit, the second position detecting unit acquires a live image of the anterior segment of the eye and a pupil region in the live image. The position of the eye to be inspected is detected based on the size of
The ophthalmologic imaging apparatus according to any one of claims 1 to 5, wherein the control unit controls the optical system moving unit based on the position detected by the second position detection unit.

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