JP6585897B2 - Ophthalmic imaging equipment - Google Patents

Description

  The present invention relates to an ophthalmologic photographing apparatus.

  In the field of ophthalmology, various apparatuses for photographing an eye to be examined are used. In recent years, an optical coherence tomography (OCT) capable of acquiring a cross-sectional image or a three-dimensional image of the fundus or anterior segment has attracted attention.

  When performing OCT, the target region of the eye to be examined needs to be included in the measurement range (scan range). Therefore, a technique for adjusting the OCT measurement range so that the region of interest of the eye to be examined is depicted in the frame is used. For example, Patent Document 1 acquires a cross-sectional image of the position of the center and the opposite end of a two-dimensional measurement range, displays the acquired cross-sectional images side by side, and displays a retinal layer included in the cross-sectional image. Discloses an apparatus configured to display a cross-sectional image on the upper end or lower end of the frame in a manner different from other cross-sectional images. According to this apparatus, it is possible to detect and notify the displacement of the retinal layer in the depth direction of the measurement range.

  In the technology disclosed in Patent Document 1, a line (center line) that passes through the center of the rectangular measurement range, and two lines that correspond to two opposite sides of the measurement range and are parallel to the center line, Three cross-sectional images along the three lines are acquired. Patent Document 1 discloses a technique for obtaining a cross-sectional image along a line passing through the center of a circular measurement range and a cross-sectional image along a circle corresponding to the periphery of the measurement range.

Patent No. 5543536

  The adjustment of the position of the target region of the eye to be examined and the OCT measurement range is desirably performed not only in the depth direction but also two-dimensionally or three-dimensionally. However, the technique disclosed in Patent Document 1 cannot detect a retinal layer shift in a direction other than the depth direction. Further, the technique disclosed in Patent Document 1 can detect a deviation due to the inclination of the eye to be examined in the direction along the cross-sectional image, but the deviation due to the inclination in the other direction can be detected with high accuracy. It is difficult to detect.

  An object of the present invention is to provide a novel technique for detecting a shift in the OCT measurement range.

An ophthalmologic photographing apparatus according to an embodiment is an ophthalmic photographing apparatus that acquires a cross-sectional image by scanning an eye to be examined using optical coherence tomography (OCT), and performs a first scan along a first scanning line in the eye to be examined. And a data acquisition unit for acquiring data by executing a second scan along a second scan line having a direction different from that of the first scan line, and analyzing a cross-sectional image based on the data acquired by the first scan Identifying the image region of the target region of the eye to be examined, analyzing the cross-sectional image based on the data acquired by the second scan, and identifying the image region of the target region, and the specific unit A display control unit for displaying information on a display unit based on a position of the image area in the cross-sectional image, and a cross-sectional image based on the data acquired by the first scan and / or the second scan. The specific part of the eye to be examined is specified from the cross-sectional image based on the obtained data, and the optical path length and / or OCT of the OCT measurement light is arranged so that the specific part is arranged at a predetermined depth position of the frame of the cross-sectional image. A condition control unit that changes an optical path length of the reference light, each of the first scanning line and the second scanning line is a line segment, and the first scanning line and the second scanning line are perpendicular to each other. And intersecting each other at the center position .

  According to the present invention, a novel technique for detecting a shift in the OCT measurement range is provided.

It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an embodiment. It is the schematic for demonstrating an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is the schematic for demonstrating an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is the schematic for demonstrating an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is the schematic for demonstrating an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is the schematic for demonstrating an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is the schematic for demonstrating an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is a flowchart showing an example of the usage pattern of the ophthalmologic imaging apparatus which concerns on embodiment. It is the schematic for demonstrating an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is the schematic for demonstrating an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment.

  An example of an embodiment of the present invention will be described in detail with reference to the drawings. An ophthalmologic photographing apparatus according to the present invention performs optical coherence tomography (OCT) of an eye to be examined. This OCT is performed on any part of the eye to be examined, such as the fundus or the anterior eye segment.

  In this specification, images acquired by OCT may be collectively referred to as OCT images. Moreover, it is possible to use the description content of the literature referred in this specification as the content of the following embodiment.

  In the following embodiment, an ophthalmologic imaging apparatus capable of executing Fourier domain type OCT will be described. In particular, the ophthalmologic photographing apparatus according to the embodiment can apply a swept source type OCT technique. Note that the configuration according to the present invention can also be applied to an ophthalmologic photographing apparatus capable of executing a type other than the swept source type, for example, a spectral domain type OCT. In the following embodiments, an apparatus combining an OCT apparatus and a fundus camera will be described. However, modalities other than the fundus camera, for example, SLO (Scanning Laser Ophthalmoscope), slit lamps, ophthalmic surgical microscopes, and the like according to the embodiment. It is also possible to combine OCT apparatuses having configurations. In addition, the configuration according to the embodiment can be incorporated into a single OCT apparatus.

  A technique for displaying a moving image of a cross section in real time by repeatedly performing an OCT scan on a substantially constant cross section is called a live scan. The live scan is used not only for adjustment of the measurement range but also for various purposes such as observation of the movement of the eye to be examined and setting of the scan position.

[Constitution]
As shown in FIG. 1, the ophthalmologic photographing apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The retinal camera unit 2 includes an optical system that is substantially the same as a conventional retinal camera and an optical system for performing OCT. The OCT unit 100 is provided with an optical system for executing OCT. The arithmetic control unit 200 includes a computer that executes various arithmetic processes and control processes.

[Fundus camera unit]
The fundus camera unit 2 shown in FIG. 1 is provided with an optical system for obtaining a two-dimensional image (fundus image) representing the surface form of the fundus oculi Ef of the eye E to be examined. The fundus image includes an observation image and a captured image. The observation image is, for example, a monochrome moving image formed at a predetermined frame rate using near infrared light. The captured image may be, for example, a color image obtained by flashing visible light, or a monochrome still image using near infrared light or visible light as illumination light. The fundus camera unit 2 may be configured to be able to acquire images other than these, such as a fluorescein fluorescent image, an indocyanine green fluorescent image, a spontaneous fluorescent image, and the like.

  The retinal camera unit 2 is provided with a chin rest and a forehead support for supporting the subject's face. Further, the fundus camera unit 2 is provided with an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the fundus oculi Ef with illumination light. The photographing optical system 30 guides the fundus reflection light of the illumination light to an imaging device (CCD image sensor (sometimes simply referred to as a CCD) 35, 38). The imaging optical system 30 guides the measurement light from the OCT unit 100 to the eye E and guides the measurement light passing through the eye E to the OCT unit 100.

  The observation light source 11 of the illumination optical system 10 is configured by, for example, a halogen lamp or an LED (Light Emitting Diode). The light (observation illumination light) output from the observation light source 11 is reflected by the reflection mirror 12 having a curved reflection surface, passes through the condensing lens 13, passes through the visible cut filter 14, and is converted into near infrared light. Become. Further, the observation illumination light is once converged in the vicinity of the photographing light source 15, reflected by the mirror 16, and passes through the relay lenses 17 and 18, the diaphragm 19 and the relay lens 20. Then, the observation illumination light is reflected at the peripheral portion (region around the hole portion) of the aperture mirror 21, passes through the dichroic mirror 46, and is refracted by the objective lens 22 to illuminate the fundus oculi Ef.

  The fundus reflection light of the observation illumination light 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, passes through the dichroic mirror 55, and is a focusing lens. It is reflected by the mirror 32 via 31. Further, the fundus reflection light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and forms an image on the light receiving surface of the CCD image sensor 35 by the condenser lens. The CCD image sensor 35 detects fundus reflected light at a predetermined frame rate, for example. On the display device 3, an image (observation image) based on fundus reflection light detected by the CCD image sensor 35 is displayed. When the photographing optical system 30 is focused on the anterior segment, an observation image of the anterior segment of the eye E is displayed.

  The imaging light source 15 is constituted by, for example, a xenon lamp or an LED. The light (imaging illumination light) output from the imaging light source 15 is applied to the fundus oculi Ef through the same path as the observation illumination light. The fundus reflection light of the imaging illumination light is guided to the dichroic mirror 33 through the same path as that 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 of the CCD image sensor 38. An image is formed on the light receiving surface. On the display device 3, an image (captured image) based on fundus reflection light detected by the CCD image sensor 38 is displayed. Note that the display device 3 that displays the observation image and the display device 3 that displays the captured image may be the same or different. In addition, when similar imaging is performed by illuminating the eye E with infrared light, an infrared captured image is displayed. It is also possible to use an LED as a photographing light source.

  An LCD (Liquid Crystal Display) 39 displays a fixation target and an eyesight measurement index. The fixation target is an index for fixing the eye E to be examined, and is used at the time of fundus photographing or OCT.

  A part of the light output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, passes through the focusing lens 31 and the dichroic mirror 55, passes through the hole of the perforated mirror 21, and then reaches the dichroic. The light passes through the mirror 46, is refracted by the objective lens 22, and is projected onto the fundus oculi Ef.

  By changing the display position of the fixation target on the screen of the LCD 39, the fixation position of the eye E can be changed. As the fixation position of the eye E, for example, as in a conventional fundus camera, a position for acquiring an image centered on the macular of the fundus oculi Ef, a position for acquiring an image centered on the optic nerve head, And a position for acquiring an image centered on the fundus center between the macula and the optic disc. It is also possible to arbitrarily change the display position of the fixation target.

  Further, the fundus camera unit 2 is provided with an alignment optical system 50 and a focus optical system 60 as in a conventional fundus camera. The alignment optical system 50 generates an index (alignment index) for performing alignment (alignment) of the apparatus optical system with respect to the eye E. The focus optical system 60 generates an index (split index) for focusing on the eye E to be examined.

  The light (alignment light) output from the LED 51 of the alignment optical system 50 is reflected by the dichroic mirror 55 via the apertures 52 and 53 and the relay lens 54, passes through the hole of the perforated mirror 21, and reaches the dichroic mirror 46. And is projected onto the cornea of the eye E by the objective lens 22.

  The corneal reflection light of the alignment light passes through the objective lens 22, the dichroic mirror 46 and the hole, part of which passes through the dichroic mirror 55, passes through the focusing lens 31, is reflected by the mirror 32, and is half mirror The light passes through 33A, is reflected by the dichroic mirror 33, and is projected onto the light receiving surface of the CCD image sensor 35 by the condenser lens. The light reception image (alignment index) by the CCD image sensor 35 is displayed on the display device 3 together with the observation image. The user performs alignment by performing the same operation as that of a conventional fundus camera. Further, the arithmetic control unit 200 may perform alignment by analyzing the position of the alignment index and moving the optical system (auto-alignment function).

  When performing the focus adjustment, the reflecting surface of the reflecting rod 67 is obliquely provided on the optical path of the illumination optical system 10. The light (focus light) output from the LED 61 of the focus optical system 60 passes through the relay lens 62, is separated into two light beams by the split indicator plate 63, passes through the two-hole aperture 64, and is reflected by the mirror 65, The light is focused on the reflecting surface of the reflecting bar 67 by the condenser lens 66 and 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 oculi Ef.

  The fundus reflection light of the focus light is detected by the CCD image sensor 35 through the same path as the cornea reflection light of the alignment light. A light reception image (split index) by the CCD image sensor 35 is displayed on the display device 3 together with the observation image. The arithmetic and control unit 200 analyzes the position of the split index and moves the focusing lens 31 and the focus optical system 60 to perform focusing as in the conventional case (autofocus function). Alternatively, focusing may be performed manually while visually checking the split indicator.

  The dichroic mirror 46 branches the optical path for OCT from the optical path for fundus imaging. The dichroic mirror 46 reflects light in a wavelength band used for OCT and transmits light for fundus photographing. In this OCT optical path, in order from the OCT unit 100 side, a collimator lens unit 40, an optical path length changing unit 41, a variable cross cylinder lens (hereinafter referred to as a VCC lens) 47, an optical scanner 42, and a focusing lens 43. A mirror 44 and a relay lens 45 are provided.

  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 of the optical path for OCT. This change in the optical path length is used for correcting the optical path length according to the axial length of the eye E or adjusting the interference state. The optical path length changing unit 41 includes, for example, a corner cube and a mechanism for moving the corner cube.

  The optical scanner 42 is disposed at a position optically conjugate with the pupil of the eye E. The optical scanner 42 changes the traveling direction of the light (measurement light LS) passing through the optical path for OCT. Thereby, the eye E can be scanned with the measurement light LS. The optical scanner 42 includes, for example, a galvanometer mirror that scans the measurement light LS in the x direction, a galvanometer mirror that scans in the y direction, and a mechanism that drives these independently. Thereby, the measurement light LS can be scanned in an arbitrary direction on the xy plane.

[OCT unit]
An example of the configuration of the OCT unit 100 is shown in FIG. The OCT unit 100 is provided with an optical system for acquiring an OCT image of the eye E. This optical system has the same configuration as a conventional swept source type OCT apparatus. That is, this optical system divides the light from the wavelength scanning type (wavelength sweep type) light source into the measurement light and the reference light, and returns the return light of the measurement light from the eye E and the reference light via the reference light path. An interference optical system that generates interference light by causing interference and detects the interference light. The detection result (detection signal) of the interference light by the interference optical system is a signal indicating the spectrum of the interference light and is sent to the arithmetic control unit 200.

  The light source unit 101 includes a wavelength scanning type (wavelength sweeping type) light source capable of scanning (sweeping) the wavelength of the emitted light, as in a general swept source type OCT apparatus. The light source unit 101 temporally changes the output wavelength in the near-infrared wavelength band that cannot be visually recognized by the human eye.

  The light L0 output from the light source unit 101 is guided to the polarization controller 103 by the optical fiber 102 and its polarization state is adjusted. The polarization controller 103 adjusts the polarization state of the light L0 guided through the optical fiber 102, for example, by applying stress from the outside to the looped optical fiber 102.

  The light L0 whose polarization state is adjusted by the polarization controller 103 is guided to the fiber coupler 105 by the optical fiber 104, and is divided into the measurement light LS and the reference light LR.

  The reference light LR is guided to the collimator 111 by the optical fiber 110 and becomes a parallel light beam. The reference light LR that has become a parallel light beam is 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 functions as a delay unit for matching the optical path length (optical distance) of the reference light LR and the optical path length of the measurement light LS. The dispersion compensation member 113 functions as a dispersion compensation means for matching the dispersion characteristics between the reference light LR and the measurement light LS.

  The corner cube 114 folds the traveling direction of the reference light LR that has become a parallel light beam by the collimator 111 in the reverse direction. The optical path of the reference light LR incident on the corner cube 114 and the optical path of the reference light LR emitted from the corner cube 114 are parallel. The corner cube 114 is movable in a direction along the incident optical path and the outgoing optical path of the reference light LR. By this movement, the length of the optical path of the reference light LR is changed.

  1 and 2, 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 optical path (reference optical path, reference) of the reference light LR. Both corner cubes 114 for changing the length of the arm) are provided, but either one of them may be provided. It is also possible to change the difference between the measurement optical path length and the reference optical path length using optical members other than these.

  The reference light LR that has passed through the corner cube 114 passes through the dispersion compensation member 113 and the optical path length correction member 112, is converted from a parallel light beam to a focused light beam by the collimator 116, enters the optical fiber 117, and is guided to the polarization controller 118. Accordingly, the polarization state of the reference light LR is adjusted.

  For example, the polarization controller 118 has the same configuration as the polarization controller 103. The reference light LR whose polarization state is adjusted by the polarization controller 118 is guided to the attenuator 120 by the optical fiber 119, and the light quantity is adjusted under the control of the arithmetic control unit 200. The reference light LR whose light amount has been adjusted by the attenuator 120 is guided to the fiber coupler 122 by the optical fiber 121.

  On the other hand, the measurement light 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. The measurement light LS converted into a parallel light beam reaches the dichroic mirror 46 via the optical path length changing unit 41, the optical scanner 42, the focusing lens 43, the mirror 44, and the relay lens 45. Then, the measurement light LS is reflected by the dichroic mirror 46, refracted by the objective lens 22, and irradiated to the eye E. The measurement light LS is scattered (including reflection) at various depth positions of the eye E. The return light of the measurement light LS including such backscattered light travels in the reverse direction on the same path as the forward path, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

  The fiber coupler 122 combines (interferes) the measurement light LS incident through the optical fiber 128 and the reference light LR incident through the optical fiber 121 to generate interference light. The fiber coupler 122 branches the interference light between the measurement light LS and the reference light LR at a predetermined branching ratio (for example, 1: 1), thereby generating a pair of interference lights LC. The pair of interference lights LC emitted from the fiber coupler 122 are guided to the detector 125 by optical fibers 123 and 124, respectively.

  The detector 125 is, for example, a balanced photodiode that includes a pair of photodetectors that respectively detect a pair of interference lights LC and outputs a difference between detection results obtained by the pair of photodetectors. The detector 125 sends the detection result (detection signal) to the arithmetic control unit 200. The arithmetic control unit 200 performs, for example, Fourier transform or the like on the spectrum distribution based on the detection result obtained by the detector 125 for each series of wavelength scans (for each A line), thereby obtaining the reflection intensity profile in each A line. Form. Further, the arithmetic control unit 200 forms image data by imaging each A-line profile.

  In this embodiment, a Michelson type interference optical system is employed, but any type of interference optical system such as a Mach-Zehnder type can be employed.

[Calculation control unit]
The configuration of the arithmetic control unit 200 will be described. The arithmetic control unit 200 analyzes the detection signal input from the detector 125 and forms an OCT image of the eye E. The arithmetic processing for this is the same as that of a conventional swept source type OCT apparatus.

  The arithmetic control unit 200 controls each part of the fundus camera unit 2, the display device 3, and the OCT unit 100. For example, the arithmetic control unit 200 displays an OCT image of the eye E on the display device 3.

  As the control of the fundus camera unit 2, the arithmetic control unit 200 controls the operation of the observation light source 11, the imaging light source 15 and the LEDs 51 and 61, the operation control of the LCD 39, the movement control of the focusing lenses 31 and 43, and the reflector 67. Movement control, movement control of the focus optical system 60, movement control of the optical path length changing unit 41, operation control of the optical scanner 42, and the like are performed.

  As the control of the OCT unit 100, the arithmetic control unit 200 controls the operation of the light source unit 101, the movement control of the corner cube 114, the operation control of the detector 125, the operation control of the attenuator 120, and the operations of the polarization controllers 103 and 118. Control and so on.

  The arithmetic and control unit 200 includes, for example, a microprocessor, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, a communication interface, and the like, as in a conventional computer. A computer program for controlling the ophthalmologic photographing apparatus 1 is stored in a storage device such as a hard disk drive. The arithmetic control unit 200 may include various circuit boards, for example, a circuit board for forming an OCT image. The arithmetic control unit 200 may include an operation device (input device) such as a keyboard and a mouse, and a display device such as an LCD.

  The fundus camera unit 2, the display device 3, the OCT unit 100, and the calculation control unit 200 may be configured integrally (that is, in a single housing) or separated into two or more cases. It may be.

[Control system]
The configuration of the control system of the ophthalmologic photographing apparatus 1 will be described with reference to FIG. In FIG. 3, some components of the ophthalmologic photographing apparatus 1 are omitted, and components particularly necessary for explaining this embodiment are selectively shown.

(Control part)
The control system of the ophthalmologic photographing apparatus 1 is configured around the control unit 210. The controller 210 includes, for example, a microprocessor, RAM, ROM, hard disk drive, communication interface, and the like. The control unit 210 is provided with a main control unit 211 and a storage unit 212.

(Main control unit)
The main control unit 211 performs the various controls described above. In particular, as shown in FIG. 3, the main control unit 211 includes the CCD image sensors 35 and 38 of the fundus camera unit 2, an imaging focusing drive unit 31A, an optical path length changing unit 41, an optical scanner 42, and an OCT focusing drive unit 43A. In addition, the light source unit 101, the reference driving unit 114A, and the detector 125 of the OCT unit 100 are controlled.

  The photographing focus driving unit 31A moves the focusing lens 31 in the optical axis direction. Thereby, the focus position of the photographic optical system 30 is changed. The main control unit 211 can control an optical system drive unit (not shown) to move the optical system provided in the fundus camera unit 2 three-dimensionally. This control is used in alignment and tracking. Tracking refers to moving the apparatus optical system in accordance with the movement of the eye E. When tracking is performed, alignment and focusing are performed in advance. Tracking maintains a suitable positional relationship in which alignment and focus are achieved by moving the apparatus optical system in real time according to the position and orientation of the eye E based on an image obtained by taking a moving image of the eye E. It is a function.

  The OCT focusing drive unit 43A moves the focusing lens 43 along the optical axis of the measurement optical path. Thereby, the focus position of the measurement light LS is changed. The focus position of the measurement light LS corresponds to the depth position (z position) of the beam waist of the measurement light LS.

  The reference driving unit 114A moves the corner cube 114 provided in the reference optical path. Thereby, the length of the reference optical path is changed. As described above, the optical path length changing unit 41 and only one of the corner cube 114 and the reference driving unit 114A may be provided.

  As shown in FIG. 3, the main control unit 211 is provided with a condition control unit 2111 and a display control unit 2112.

(Condition control unit)
The condition control unit 2111 controls conditions related to OCT. Conditions relating to OCT include conditions relating to scanning of the measurement light LS (scanning conditions), conditions relating to the focus of the measurement light LS (focus conditions), conditions relating to an interference state between the measurement light LS and the reference light LR (interference conditions), and the like. is there. The scan conditions include a scan pattern related to the control of the optical scanner 42 and a scan interval. The scan pattern is a condition that represents the shape of the scan, and specific examples include a line scan in a line segment, a circle scan in a circular shape, a raster scan (three-dimensional scan), and the like. The focus condition includes a focus position of the measurement light LS related to control of the focus lens 43 (OCT focus drive unit 43A) and the like. The interference condition relates to the control of the focusing lens 43 (OCT focusing driving unit 43A), the corner cube 114 (reference driving unit 114A), the polarization controller 118, and the attenuator 120. The condition control unit 2111 executes control based on the set condition. In addition, the conditions regarding OCT are not limited to these, For example, there exists diopter correction according to the diopter of the eye E to be examined.

(Display control unit)
The display control unit 2112 displays various information on the display unit 241. Processing executed by the display control unit 2112 will be described later.

(Memory part)
The storage unit 212 stores various data. Examples of the data stored in the storage unit 212 include OCT image image data, fundus image data, and examined eye information. The eye information includes information about the subject such as patient ID and name, and information about the eye such as left / right eye identification information. The storage unit 212 stores various programs and data for operating the ophthalmologic photographing apparatus 1.

(Image forming part)
The image forming unit 220 forms image data of a cross-sectional image of the fundus oculi Ef based on the detection signal from the detector 125. That is, the image forming unit 220 forms image data of the eye E based on the detection result of the interference light LC by the interference optical system. This process includes processes such as noise removal (noise reduction), filter processing, and FFT (Fast Fourier Transform), as in the case of the conventional swept source type OCT. The image data acquired in this way is a data set including a group of image data formed by imaging reflection intensity profiles in a plurality of A lines (paths of the measurement light LS in the eye E). is there.

  In order to improve the image quality, it is possible to superimpose (addition average) a plurality of data sets acquired by repeating scanning with the same pattern a plurality of times.

  The image forming unit 220 includes, for example, the circuit board described above. In this specification, “image data” and “image” based thereon may be identified. Moreover, the part of the eye E to be examined and the image thereof may be identified.

(Data processing part)
The data processing unit 230 performs various types of data processing (image processing) and analysis processing on the OCT image formed by the image forming unit 220. For example, the data processing unit 230 executes correction processing such as image brightness correction and dispersion correction. Further, the data processing unit 230 performs various types of image processing and analysis processing on the image (fundus image, anterior eye image, etc.) obtained by the fundus camera unit 2.

  The data processing unit 230 can form volume data (voxel data) of the eye E by performing known image processing such as interpolation processing for interpolating pixels between cross-sectional images. When displaying an image based on volume data, the data processing unit 230 performs a rendering process on the volume data to form a pseudo three-dimensional image when viewed from a specific viewing direction.

  The data processing unit 230 can perform alignment between the fundus image and the OCT image. When the fundus image and the OCT image are acquired in parallel, since both optical systems are coaxial, the optical axis of the imaging optical system 30 is used to (substantially) simultaneously acquire the fundus image and the OCT image. Can be aligned with reference to. Regardless of the acquisition timing of the fundus image and the OCT image, the front image obtained by projecting at least a part of the image area corresponding to the fundus oculi Ef of the OCT image onto the xy plane is aligned with the fundus image. By doing so, it is possible to align the OCT image and the fundus image. This alignment method is applicable even when the fundus image acquisition optical system and the OCT optical system are not coaxial. Even if both optical systems are not coaxial, if the relative positional relationship between both optical systems is known, the same alignment as in the coaxial case is executed with reference to this relative positional relationship. It is possible.

(Attention area identification part)
The data processing unit 230 is provided with an attention area specifying unit 231. The attention area specifying unit 231 specifies an image area (attention area) corresponding to the attention site of the eye E by analyzing the cross-sectional image formed based on the data acquired by the OCT scan.

  The analyzed cross-sectional image is an image formed by the image forming unit 220 or the data processing unit 230. For example, the analyzed cross-sectional image may be a cross-sectional image (B-scan image) formed by the image forming unit 220 along the OCT scan scanning line. Alternatively, the analyzed cross-sectional image is a two-dimensional cross-sectional image representing an arbitrary cross-section obtained by performing MPR processing (multi-section reconstruction) on a three-dimensional image based on a plurality of cross-sectional images formed by the image forming unit 220. It may be. As a further example, the analyzed cross-sectional image may be a three-dimensional image formed by the data processing unit 230 or a part thereof. The cross-sectional image to be analyzed may be a still image or a moving image frame. When frames of moving images are analyzed, all frames may be analyzed, or analysis may be performed by thinning out frames that are sequentially acquired.

  The type of the target region of the eye E is designated in advance. In the present embodiment, an arbitrary target region of the fundus oculi Ef is designated. Specific examples include the optic disc, macular, fovea, blood vessel, retina, choroid, sclera, vitreous, and lesion. Note that the site of interest may be the whole or a part of any of the exemplified sites, or may be at least a part of a combination of two or more exemplified sites. For example, the region of interest may be the entire layer of the retina or one or more layered tissues constituting the retina. It is also possible to designate at least a part of a part other than the exemplified part as a target part.

  Processing executed by the attention area specifying unit 231 will be described. The attention area specifying unit 231 performs image analysis based on pixel values and / or pixel positions in the cross-sectional image. In such image analysis, known techniques such as binarization, edge detection, threshold processing, pattern recognition, smoothing, filtering, and labeling are applied. Also, an algorithm composed of a combination of two or more such image processes is applied.

(Position determination unit)
The data processing unit 230 is further provided with a position determination unit 232. The position determination unit 232 determines the position of the attention area identified by the attention area identification unit 231 in the cross-sectional image. For example, the position determination unit 232 determines whether or not the region of interest covers the edge of the cross-sectional image (that is, determines whether or not the region of interest intersects or contacts the edge of the cross-sectional image). Specifically, the position determination unit 232 determines whether or not the attention area covers the upper edge and / or the lower edge of the cross-sectional image. This process is executed, for example, in the same manner as in Patent Document 1 (Japanese Patent No. 5543536). Further, the position determination unit 232 can determine whether or not the region of interest covers the left edge and / or the right edge of the cross-sectional image. This process is executed in the same manner.

  The position determination unit 232 can determine the position where the region of interest intersects or contacts the edge of the cross-sectional image. Further, the position determination unit 232 can determine the extent to which the attention area intersects the edge of the cross-sectional image. The degree of this intersection represents, for example, how far the position where the region of interest intersects one edge is away from the adjacent edge. As a specific example, when the attention area intersects with the upper edge, a distance between the intersection position and the left edge (or right edge) or an index indicating the degree of this distance is obtained.

  The data processing unit 230 that functions as described above includes, for example, a microprocessor, a RAM, a ROM, a hard disk drive, a circuit board, and the like. In a storage device such as a hard disk drive, a computer program for causing the microprocessor to execute the above functions is stored in advance.

(User interface)
The user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes the display device of the arithmetic control unit 200 and the display device 3 described above. The operation unit 242 includes the operation device of the arithmetic control unit 200 described above. The operation unit 242 may include various buttons and keys provided on the housing of the ophthalmologic photographing apparatus 1 or outside. Further, the display unit 241 may include various display devices such as a touch panel provided in the housing of the fundus camera unit 2.

  The display unit 241 and the operation unit 242 do not need to be configured as individual devices. For example, a device in which a display function and an operation function are integrated, such as a touch panel, can be used. In that case, the operation unit 242 includes the touch panel and a computer program. The operation content for the operation unit 242 is input to the control unit 210 as an electrical signal. Further, operations and information input may be performed using the graphical user interface (GUI) displayed on the display unit 241 and the operation unit 242.

[Operation]
Several examples relating to the operation of the ophthalmologic photographing apparatus 1 will be described.

(Operation example related to scan pattern)
The OCT scan applied in the present embodiment is a live scan, for example. The live scan may be performed in parallel with the tracking. In the live scan, the OCT scan with the same scan pattern is repeatedly executed. At this time, a fixation target is presented to the eye E. Thereby, a substantially constant cross section is repeatedly OCT scanned, and a moving image of the cross section obtained thereby can be displayed in real time. At least a part of the frames sequentially acquired by such a live scan is subjected to the above-described image analysis.

  In the following operation example, a scan pattern composed of two scan lines (first scan line L1 and second scan line L2) is applied. During the scan, the first scan along the first scan line L1 and the second scan along the second scan line L2 are executed alternately. Note that “executing the first scan and the second scan alternately” is not only a case where one first scan and one second scan are executed alternately, but one or more first scans. This is a concept including a case where scanning and one or more second scannings are alternately executed. In addition, when a scan pattern including three or more scan lines is applied, an operation of cyclically executing the first to third scan lines in a predetermined order is also included in this concept.

  Typical examples of scan patterns are shown in FIGS. 4A to 4E. Each arrow indicates the direction of scanning. The length of each arrow indicates the length of scanning. In addition, the setting of the position of the fundus oculi Ef to which the scan pattern as exemplified below is applied is performed by, for example, one of the following methods: the position of the fundus oculi Ef to which the scan pattern is applied is set; The position of the fundus oculi Ef to which another scan pattern is applied is set, and the application position of the scan pattern is set using the result (for example, the position of the three-dimensional measurement region to which the three-dimensional scan is applied is set) Then, a part of the three-dimensional measurement area is set as the application position of the scan pattern); the application position of the scan pattern is set using the result of setting the fixation position.

  The scan pattern shown in FIG. 4A includes a line-shaped first scanning line L1 extending in the horizontal direction (x direction) and a line-shaped second scanning line L2 extending in the vertical direction (y direction). The first scanning line L1 and the second scanning line L2 are orthogonal to each other at the center position. That is, the scan pattern shown in FIG. 4A is a cross-shaped scan pattern composed of two line-shaped scan lines orthogonal to each other at the center position. The intersecting position of the first scanning line L1 and the second scanning line L2 is arranged, for example, at a site of interest (macular (fovea), optic disc, etc.) of the fundus oculi Ef.

  The scan pattern shown in FIG. 4B includes a line-shaped first scanning line L1 extending in the horizontal direction and a line-shaped second scanning line L2 extending in the vertical direction. The first scanning line L1 and the second scanning line L2 are orthogonal to each other at a position other than the center position. In general, the intersection position between the first scanning line and the second scanning line can be arbitrarily set.

  The scan pattern shown in FIG. 4C includes a line-shaped first scanning line L1 extending in the horizontal direction and a line-shaped second scanning line L2 extending in the vertical direction. The first scanning line L1 and the second scanning line L2 are perpendicular to each other, but do not intersect each other. In general, the relative position between the first scanning line and the second scanning line can be arbitrarily set.

  The scan pattern shown in FIG. 4D includes a line-shaped first scanning line L1 extending in an oblique direction and a line-shaped second scanning line L2 extending in a vertical direction. The first scanning line L1 and the second scanning line L2 cross each other at an angle other than vertical. In general, the relative angle between the first scanning line and the second scanning line is arbitrary. In particular, when the first scanning line and the second scanning line intersect, their intersection angle can be set arbitrarily.

  The scan pattern shown in FIG. 4E includes a line-shaped first scanning line L1 extending in the horizontal direction and a line-shaped second scanning line L2 extending in the vertical direction. The first scanning line L1 and the second scanning line L2 are orthogonal to each other at the center position. The first scanning line L1 is shorter than the second scanning line L2. In general, the length of the first scanning line and the length of the second scanning line can be arbitrarily set.

(Operation example regarding display)
An example regarding the display of information is shown in FIG. In this example, the case where the scan pattern shown in FIG. 4A is applied will be described. However, the same display process can be executed when another scan pattern is applied.

  A display screen 300 shown in FIG. 5 is displayed on the display unit 241 by the display control unit 2112. The display screen 300 is provided with a first cross-sectional image display area 301, a second cross-sectional image display area 302, and a front image display area 303.

  In the front image display area 303, an observation image H of the fundus oculi Ef is displayed. The observation image H is an infrared moving image. The front image display area 303 further displays an image representing the first scanning line L1 (first scanning line image) and an image representing the second scanning line L2 (second scanning line image). The first scanning line image and the second scanning line image are indicated by the same reference numerals as the first scanning line L1 and the second scanning line L2, respectively, in FIG. As described above, in this example, the scan pattern including the first scan line L1 and the second scan line L2 shown in FIG. 4A is applied. Therefore, the first scanning line image L1 and the second scanning line image L2 shown in FIG. 5 are two line-segment scanning lines orthogonal to each other at the center position. The first scanning line image L1 and the second scanning line image L2 are respectively arrow-shaped images, and represent the scanning directions in the first scanning line L1 and the second scanning line L2, respectively. In this example, the first scanning line image L1 and the second scanning line image L2 are displayed on the observation image H. A symbol R indicates an outer edge of a two-dimensional region stretched by the first scanning line image L1 and the second scanning line image L2. It can be said that the outer edge R indicates the range of the three-dimensional measurement region that is the target of the raster scan (three-dimensional scan). The outer edge R may be displayed or may not be displayed.

  In the first cross-sectional image display area 301, a moving image (first moving image) G1 obtained by repeatedly scanning the first scanning line L1 is displayed. In the second cross-sectional image display area 302, a moving image (second moving image) G2 obtained by repeatedly scanning the second scanning line L2 is displayed. As described above, in this example, the first scan along the first scan line L1 and the second scan along the second scan line L2 are executed alternately.

  The display control unit 2112 generates a cross-sectional image that is sequentially formed by the image forming unit 220 from data obtained by the first scan that is repeatedly executed in such alternate scans, for example, at a predetermined frame rate (for example, repetition of the first scan). The first moving image G1 is displayed by displaying it in the first cross-sectional image display area 301 at a rate equal to the rate or an integer multiple thereof. Similarly, the display control unit 2112 generates a cross-sectional image that the image forming unit 220 sequentially forms from data obtained by the second scan that is repeatedly executed in the alternate scan at a predetermined frame rate (for example, the repetition of the second scan). The second moving image G2 is displayed by displaying it in the second cross-sectional image display region 302 at a rate equal to or an integral multiple of the rate.

  The first cross-sectional image display region 301 is arranged in a direction corresponding to the first scanning line L1 (first scanning line image L1). In this example, the first cross-sectional image display area 301 is rectangular, and the direction of the upper side and the lower side thereof coincides with the direction of the first scanning line image L1. That is, in FIG. 5, the first scanning line image L1 is a line segment (arrow) extending in the left-right direction, and the upper side and the lower side of the first cross-sectional image display region 301 extend in the left-right direction. In the observation image H, the left-right direction corresponds to the x direction, and the up-down direction corresponds to the y direction. In the first cross-sectional image display region 301, the direction of the upper side and the lower side (left and right direction) corresponds to the x direction, and the left side and right side (up and down direction) correspond to the z direction. Therefore, the direction (x direction) of the first scanning line image L1 displayed on the observation image H and the direction (x direction) of the cross section of the first moving image G1 displayed in the first cross section image display region 301 are determined. Match.

  Similarly, the second cross-sectional image display region 302 is arranged in a direction corresponding to the first scanning line L2 (first scanning line image L2). In this example, the second cross-sectional image display area 302 is rectangular, and the direction of the left side and the right side thereof coincides with the direction of the second scanning line image L2. That is, in FIG. 5, the second scanning line image L2 is a line segment (arrow) extending in the vertical direction, and the left side and the right side of the second cross-sectional image display region 302 extend in the vertical direction. As described above, in the observation image H, the left-right direction corresponds to the x direction, and the up-down direction corresponds to the y direction. In the second cross-sectional image display area 302, the direction of the left side and the right side (up and down direction) corresponds to the y direction, and the upper side and the lower side (left and right direction) correspond to the z direction. Therefore, the direction (y direction) of the second scanning line image L2 displayed on the observation image H and the direction (y direction) of the cross section of the second moving image G2 displayed in the second cross section image display region 302 are determined. Match.

  In addition, information indicating the correspondence between the first scanning line L1 (first scanning line image L1) and the first moving image G1 (first correspondence information), the second scanning line (second scanning line image L2), and the second Information indicating the correspondence with the moving image G2 (second correspondence information) can be displayed. In this example, display colors are used as the first and second correspondence information. Specifically, the display control unit 2112 displays the first scanning line image L1 and the frame of the first moving image G1 (the frame of the first cross-sectional image display region 301) in the first color, and performs the second scanning. The line image L2 and the frame of the second moving image G2 (the frame of the second cross-sectional image display area 302) are displayed in a second color different from the first color.

  On the left side of the first cross-sectional image display area 301, a marker 304 indicating the focus position of the measurement light LS is provided. The focusing position of the measurement light LS corresponds to the position of the focusing lens 43. The focusing lens 43 is moved by the OCT focusing drive unit 43A. The display control unit 2112 displays the marker 304 based on the current position of the focusing lens 43 (that is, the control state with respect to the OCT focusing driving unit 43A). The in-focus position changes in the z direction, and the direction (vertical direction) along the left side of the first cross-sectional image display region 301 corresponds to the z direction. Therefore, the position of the marker 304 changes along the left side.

  Further, the user can move the marker 304. The operation for that is performed by touch operation which touches a desired position, when the display part 241 is a touch panel. When the display unit 241 is not a touch panel, the user operates the operation unit 242. This operation is, for example, an operation of clicking a desired position or an operation of dragging the marker 304. When the marker 304 is moved, the main control unit 211 controls the OCT focusing drive unit 43A based on the position of the marker 304 after the movement, thereby focusing on the position corresponding to the position of the marker 304 after the movement. The lens 43 is moved.

  The area provided on the display screen 300 is not limited to that shown in FIG. As typical examples, an area where information about the subject and the eye E is displayed, an area where the anterior eye image of the eye E is displayed (anterior eye image display area), various software keys, and the like May be provided on the display screen 300.

  An example relating to the display of the anterior segment image and the processing executed accordingly will be described. The ophthalmologic photographing apparatus according to this example includes a pair of video cameras for obtaining an image of the anterior segment of the eye E to be examined. The pair of video cameras captures the anterior segment simultaneously from different directions. The display control unit 2112 displays an upper half image area (upper half area) of the video obtained by the first video camera and a lower half image area (lower half area) of the video obtained by the second video camera. They are displayed side by side in the anterior segment image display area. The control unit 210 (or the data processing unit 230) detects an image (specific part image) of a specific part (pupil, iris, etc.) by analyzing the upper half area and the lower half area, and specifies the specific part in the upper half area. The displacement between the region image and the specific region image in the lower half region is calculated, and the optical system (OCT optical system, fundus camera optical system) is moved so as to cancel the displacement. Thereby, alignment of the optical system with respect to the eye E can be performed. Further, the above processing is repeatedly executed in real time based on frames sequentially acquired by a pair of video cameras, thereby performing tracking for causing the optical system to follow the movement of the eye E, and performing OCT and imaging of the fundus oculi Ef. Or observation.

(Usage form)
A usage pattern of the ophthalmologic photographing apparatus 1 will be described. FIG. 6 shows an example of usage pattern. In this example, in order to perform a three-dimensional scan of the fundus oculi Ef, a live scan is executed with the scan pattern shown in FIG. 4A.

  It is assumed that the preparation operation for OCT measurement has already been executed. Preparation operations include observation of fundus oculi Ef, alignment, focusing, setting of conditions relating to OCT, and the like. Further, tracking may be started at an arbitrary timing.

(S1: 3D scan measurement range setting)
In this example, first, the measurement range of the fundus oculi Ef to which the three-dimensional scan (raster scan) is applied is set. In the subsequent OCT, the condition control unit 2111 controls the optical scanner 42 and the like based on the set measurement range. The measurement range is set manually or automatically.

  When the measurement range is executed manually, for example, an observation image (real-time moving image) of the fundus oculi Ef is displayed in the front image display area 303 of the display screen 300 shown in FIG. On this observation image, an image indicating the measurement range of the three-dimensional scan (for example, an image representing the frame R) is displayed. By using the operation unit 242, the user can move the frame R to a desired position on the observation image. At this time, it is only necessary that the relative position between the observation image (that is, fundus oculi Ef) and the frame R (that is, the measurement range) can be changed. For example, this relative position can be changed by adjusting the fixation position.

  When the measurement range is automatically set, for example, the data processing unit 230 analyzes an image (an observation image, a captured image, an OCT image, etc.) of the fundus oculi Ef and specifies an image position corresponding to a predetermined part of the fundus oculi Ef. . This process can be executed in the same manner as the process for specifying the region of interest. Further, the data processing unit 230 sets a measurement range based on the specified image position. As a typical example, when a single image position is specified, the measurement range is set so that this image position is arranged in the center. As another example, when two or more image positions are specified, the measurement range is set to include all the image positions.

  An example of the screen displayed on the display unit 241 at the end of step S1 is shown in FIG. 7A. The display screen 300 shown in FIG. 7A has the same layout as that shown in FIG. At the end of step S1, no image is displayed in the first slice image display area 301 and the second slice image display area 302, but the observation image H is displayed in the front image display area 303. Further, on the observation image H, a frame R representing the measurement range set in step S1, and a first scanning line image L1 and a second scanning line image L2 representing a scanning pattern applied in the live scan in step S2. Is displayed. In this example, the scan pattern shown in FIG. 4A is applied. The first scanning line image L1 and the second scanning line image L2 are two lines orthogonal to each other at the center position, and the intersection position thereof coincides with the center of the measurement range. The first scanning line image L1 is a line extending in the x direction, and the second scanning line image L2 is a line extending in the y direction.

(S2: Start of live scan)
After step S1, the main control unit 211 starts a live scan with the scan pattern shown in FIG. 4A (in response to a predetermined trigger).

  When the live scan is started, the display control unit 2112 displays the cross-sectional moving image (first moving image G1) indicated by the first scanning line image L1 together with the observation image H already displayed in the first cross-sectional image display area. 301, and the moving image (second moving image G2) of the cross section indicated by the second scanning line image L2 is displayed in the second cross sectional image display area 302 (see FIG. 7B).

(S3: Identification of region of interest in cross-sectional image)
When the live scan is started, the main control unit 211 sends the frame of the first moving image G1 and the frame of the second moving image G2 acquired sequentially to the data processing unit 230. Alternatively, the main control unit 211 selects some of the sequentially acquired frames and sends them to the data processing unit 230.

  The attention area identification unit 231 identifies an image area (attention area) corresponding to a predetermined attention area by analyzing the frame of the first moving image. Similarly, the attention area specifying unit 231 specifies an image area (attention area) corresponding to a predetermined attention area by analyzing the frame of the second moving image. In this example, for example, all layers of the retina are specified as the attention area. This process includes, for example, a process of specifying the inner boundary membrane and a process of specifying the retinal pigment epithelium layer. The first moving image G1 and the second moving image G2 shown in FIG. 7B represent a plurality of layer tissues of the retina.

(S4: Determination of position of attention area)
The position determination unit 232 determines whether or not the region of interest specified by analyzing the frame of the first moving image G1 in step S3 covers the edge (for example, the upper edge and / or the lower edge) of this frame. Similarly, the position determination unit 232 determines whether or not the region of interest specified by analyzing the frame of the second moving image G2 in step S3 covers the edge (for example, the upper edge and / or the lower edge) of this frame. To do. These determination results are sent to the control unit 210 in association with the analyzed frame. For example, when it is determined that the region of interest in the frame of the first moving image G1 covers the edge of this frame, a flag is assigned to this frame (or the first moving image G1).

(S5: Control of information display)
The display control unit 2112 performs control related to information display based on the determination result obtained in step S4. That is, the display control unit 2112 has a mode in which a cross-sectional image (moving image) determined that the attention area covers the frame of the frame is different from a cross-sectional image (moving image) determined that the attention area does not cover the frame of the frame. To display.

  Examples of this display mode difference include a display size difference, a frame mode difference, and information added to a cross-sectional image. As an example of the difference in display size, a cross-sectional image that is determined that the attention area covers the frame of the frame is displayed relatively large, and a cross-sectional image that is determined that the attention area does not cover the frame of the frame is displayed relatively small Can be made. As an example of the difference in the form of the frame, a cross-sectional image determined that the attention area covers the frame of the frame and a cross-sectional image determined that the attention area does not cover the frame of the frame are within the frames of different colors or thicknesses. Can be displayed. As an example of the difference in information added to the cross-sectional image, in the vicinity of the cross-sectional image where it is determined that the region of interest covers the frame of the frame, the determination result (the region of interest covers the frame, an error, Information indicating the position, the extent of the frame, etc.) can be displayed. In addition, information indicating the determination result (not falling on the frame, appropriateness, etc.) can be displayed in the vicinity of the cross-sectional image where it is determined that the attention area does not cover the frame. In addition, it is possible to selectively display only the cross-sectional image that is determined that the region of interest covers the frame.

(S6: Measurement range adjustment)
The user can adjust the measurement range with reference to the information displayed in step S5. When the attention area covers the upper edge and / or the lower edge of the frame of the frame, the user uses the operation unit 242 so that the attention area does not cover both the upper edge and the lower edge (or one). The measurement range can be adjusted in the depth direction (depth direction, z direction). The adjustment in the depth direction is performed by adjusting the optical path length of the measurement light LS and / or the optical path length of the reference light LR.

  When the attention area covers the left edge and / or the right edge of the frame of the frame, the user uses the operation unit 242 so that the attention area does not cover both the left edge and the right edge (or one). The measurement range can be adjusted in the horizontal direction (x direction and / or y direction). The adjustment in the horizontal direction is executed, for example, by moving the frame R displayed on the observation image H (that is, by changing the operation range of the optical scanner 42). Alternatively, the adjustment in the horizontal direction can be performed by adjusting the fixation position or by adjusting the position of the optical system (fundus camera unit 2).

  It is also possible to automatically adjust the measurement range. In that case, the position determination unit 232 obtains the intersection position or degree of intersection between the region of interest and the edge, and the main control unit 211 adjusts the optical path length, the light based on the obtained intersection position or degree of intersection. Adjustment of the operating range of the scanner 42, adjustment of the fixation position, adjustment of the position of the optical system, and the like are executed.

  As another example for automatically adjusting the measurement range, while monitoring the positional relationship between the region of interest identified sequentially and the edge, so as to satisfy a predetermined condition (for example, at least one of the edges) It is possible to configure such that any one of the above adjustments is performed (so that the region of interest does not cover the part). In this process, it is possible to determine the adjustment direction based on the intersection position sequentially acquired by the position determination unit 232, or to determine the adjustment amount based on the intersection position or the degree of intersection.

(S7: End of live scan)
After the adjustment of the measurement range in step S6, the main control unit 211 ends the control for the live scan (in response to a predetermined trigger).

(S8: Execution of 3D scan)
After the live scan ends, the main control unit 211 causes the fundus oculi Ef to perform a three-dimensional scan (in response to a predetermined trigger).

(S9: Formation of 3D image)
The image forming unit 220 forms a plurality of cross-sectional images (B-scan images) along a plurality of scanning lines constituting the raster scan based on the data collected in step S8. Further, the data processing unit 230 forms a three-dimensional image based on the plurality of cross-sectional images formed by the image forming unit 220.

(S10: Display of 3D image)
The data processing unit 230 renders the three-dimensional image formed in step S9. The display control unit 2112 displays an image (three-dimensional image) based on the image data formed by this rendering. A cross-sectional image formed by MPR processing or the like can also be displayed.

(Other operation examples)
Another example of operations that can be executed according to this embodiment will be described.

  The scan position change described above can be executed, for example, as follows. The scan position is changed manually or automatically. In the case of manual operation, the user touches a desired position on the observation image H. Alternatively, the user touches a desired position using the operation unit 242 or drags the first and second scan line images L1 and L2 using the operation unit 242. On the other hand, in the case of automatic control, the condition control unit 2111 (or the data processing unit 230) analyzes the observation image H and specifies the position of a specific part (macular, fovea, optic disc, blood vessel, lesion part, etc.). The scan position is set so as to pass through the specific part. At this time, for example, the scan value is set so that the intersection position of the first and second scan lines L1 and L2 matches the specific part by the above analysis.

  The change of the scan position includes at least one of parallel movement and rotational movement. In such movement, the relative position between the first scanning line L1 and the second scanning line L2 is maintained. For example, when the scan pattern shown in FIG. 4A is applied, the first scan line L1 (first scan line image L1) and the second scan line L2 (second scan line image) are obtained before and after parallel movement and / or rotational movement. L2) are orthogonal at each other's central position.

  In such scanning position movement control, the condition control unit 2111 sets the first scanning line L1 and the second scanning line L2 in the same direction in the same amount (in accordance with the change contents (movement direction and movement amount) of the scan position). This is executed by changing the setting for controlling the optical scanner 42 so that the optical scanner 42 is moved by the same distance.

  OCT condition change input may be performed on one or both of the first moving image G1 and the second moving image G2. As an example of the OCT condition, there is a change in the focus position (for example, control using the marker 304) described above.

  Other examples include the optical path length of the measurement light LS and / or the optical path length of the reference light LR. The optical path length of the measurement light LS is changed by controlling the optical path length changing unit 41. The optical path length of the reference light LR is changed by controlling the corner cube 114 (reference driving unit 114A). When the optical path length of the measurement light LS and / or the reference light LR is changed, the optical path length difference between the measurement light LS and the reference light LR changes, and as a result, the first moving image L1 and the second moving image G2 The drawing position of the fundus tissue in this frame moves in the z direction. Such a change input of the rendering position is performed, for example, by touching a desired position on the moving image or by using a marker similar to the marker 304. Alternatively, the condition control unit 2111 (or the data processing unit 230) controls to specify a specific part of the fundus oculi Ef (fundus surface, predetermined layer tissue, etc.) and arrange the specific part at a predetermined z position of the frame. It is also possible to configure so that The OCT conditions are not limited to those exemplified above.

  In the above example, two moving images (G1 and G2) along two scanning lines (L1 and L2) are displayed in real time. However, it may be configured to acquire three or more moving images along three or more scanning lines. In this case, all the moving images acquired in parallel can be displayed side by side, but a part of the moving images can be selectively displayed in consideration of the display space. In this case, three or more scanning lines are scanned cyclically. Further, the display control unit 2112 displays two or more moving images among three or more moving images based on data sequentially acquired by three or more scanning lines.

  The user can select a moving image to be displayed. This selection operation is executed, for example, by designating a desired one of three or more scanning line images displayed on the observation image. Further, in response to the selection of several moving images, it is possible to automatically select other moving images previously associated with the moving images and display these moving images side by side. The corresponding moving image is, for example, a moving image on a scanning line orthogonal to the scanning line of the previously selected moving image.

[Action / Effect]
Several actions and effects of the ophthalmologic photographing apparatus according to this embodiment will be described.

  The ophthalmologic photographing apparatus according to the embodiment acquires a cross-sectional image by scanning the eye to be examined using OCT. Furthermore, the ophthalmologic photographing apparatus includes a data acquisition unit, a specifying unit, and a display control unit.

  The data acquisition unit executes a first scan along the first scan line (L1) in the eye to be examined and a second scan along the second scan line (L2) whose direction is different from that of the first scan line (L1). Get the data. The data acquisition unit includes an optical system for OCT. In the above embodiment, the OCT optical system includes the optical system included in the OCT unit 100 and the optical system arranged in the path of the measurement light LS in the fundus camera unit 2. Furthermore, the data acquisition unit may include a component that processes data acquired by the optical system for OCT. In the above embodiment, this component includes at least the image forming unit 200.

  The specifying unit analyzes a cross-sectional image (the first moving image G1 or a frame thereof) based on the data acquired by the first scan, and specifies an image region of the attention site of the eye to be examined. Further, the specifying unit analyzes the cross-sectional image (the second moving image G2 or its frame) based on the data acquired by the second scan, and specifies the image region of the site of interest. In the above embodiment, the specifying unit includes the attention area specifying unit 231.

  The display control unit (2112) causes the display unit to display information based on the position of the image area specified by the specifying unit in the cross-sectional image. In the above embodiment, this information display control corresponds to step S5 in FIG.

  The display means may be provided in the ophthalmologic photographing apparatus (display unit 241) or a display device connected to the ophthalmic photographing apparatus.

  According to such an embodiment, information can be displayed based on the drawing position of the region of interest in a plurality of cross-sectional images representing a plurality of cross-sections having different directions. Therefore, unlike the technique disclosed in Patent Document 1 that can detect only the shift of the rendering position in the depth direction, it is possible to detect a two-dimensional or three-dimensional shift and notify the user.

  Further, in the technique disclosed in Patent Document 1, since three parallel cross-sectional images are acquired and misalignment is detected, only misalignment in a direction along these cross sections (all in the same direction) is highly accurate. It cannot be detected. On the other hand, according to the present embodiment, it is configured to analyze a plurality of cross-sectional images having different directions, and thus it is possible to detect a positional shift in a plurality of directions with high accuracy.

  In the embodiment, the data acquisition unit can alternately execute the first scan and the second scan. Furthermore, the display control unit displays a first moving image (G1) based on data sequentially acquired by the first scan and a second moving image (G2) based on data sequentially acquired by the second scan. It can be displayed on the means.

  According to such a configuration, it is possible to simultaneously observe a plurality of cross-sectional images having different directions. That is, it is possible to simultaneously grasp how a plurality of cross sections having different directions are depicted in a plurality of moving images. Therefore, it is possible to easily grasp the three-dimensional deviation of the measurement range by OCT. Therefore, according to the ophthalmologic photographing apparatus of the embodiment, for example, it is possible to easily optimize the measurement range by OCT (for example, three-dimensional scan) executed after observation of a moving image.

  In the above embodiment, the display control unit can display the first moving image in the direction corresponding to the first scanning line and the second moving image in the direction corresponding to the second scanning line side by side.

  According to such a configuration, by displaying the moving image in the direction corresponding to the direction of the scanning line, it is possible to easily grasp the correspondence relationship between the plurality of scanning lines and the plurality of moving images, and to draw the moving image. It is possible to easily recognize the orientation of the cross section of the tissue.

  In the above embodiment, data acquisition by the data acquisition unit and moving image display by the display control unit can be executed in parallel. Thereby, it is possible to observe in real time the first moving image representing the cross section along the first scanning line and the second moving image representing the cross section along the second scanning line.

  In the above-described embodiment, the display control unit displays a cross-sectional image in which the region of interest specified by the specifying unit is applied to the edge of the cross-sectional image in a manner different from other cross-sectional images (cross-sectional images in which the region of interest does not cover the edge) It can be displayed. In particular, the display control unit can display a cross-sectional image in which the region of interest specified by the specifying unit is applied to at least one of the upper edge and the lower edge of the cross-sectional image in a manner different from other cross-sectional images. A specific example is shown in step S5 of FIG.

  According to such a configuration, the user can easily discriminate between a cross-sectional image in which the region of interest is appropriately depicted and a cross-sectional image that is not properly displayed. Thereby, the user can easily grasp the direction in which the attention area is appropriately measured and the direction in which the attention area is not appropriately measured.

  In the above embodiment, the first scanning line and the second scanning line may be set in the three-dimensional measurement range of the eye to be examined. Furthermore, the display control unit can display information based on the identification result by the identification unit before performing the OCT of the entire three-dimensional measurement range. As a specific example, in the above embodiment, a cross-shaped scan pattern is set within the measurement range of the three-dimensional scan (steps S1 and S2), and a live scan is executed with the cross-shaped scan pattern (step S2). The measurement range is adjusted based on the data obtained by this live scan (steps S3 to S6), and a three-dimensional scan is executed (step S8).

  According to such a configuration, it is possible to perform a three-dimensional scan after adjusting the measurement range using a plurality of cross-sectional images having different directions. Therefore, it is possible to appropriately perform a three-dimensional scan of the target region of the eye to be examined.

  The scan pattern including the first scan line and the second scan line can be arbitrarily set. For example, the following scan pattern can be applied. As the first aspect, a scan pattern in which the first scan line (L1) and the second scan line (L2) intersect can be applied (see, for example, FIGS. 4A, 4B, 4D, and 4E). ). In the first aspect, the first scanning line (L1) and the second scanning line (L2) may cross each other at the center position (see, for example, FIGS. 4A and 4E). As a second aspect, each of the first scanning line (L1) and the second scanning line (L2) is a line segment, and the first scanning line (L1) and the second scanning line (L2) are perpendicular to each other. (See, for example, FIGS. 4A, 4B, 4C, and 4E).

  A scan pattern can be set according to the measurement target. For example, conditions such as a measurement mode, an analysis mode, and a fixation position can be associated with a scan pattern in advance, and a scan pattern corresponding to the set condition can be selectively applied. Further, the scan pattern size may be arbitrarily changed.

  The ophthalmologic photographing apparatus according to the embodiment may include a photographing unit that photographs a subject's eye and acquires a front image. In the above-described embodiment, the photographing unit includes a fundus photographing optical system stored in the fundus camera unit 2, and particularly includes an optical system for acquiring an observation image (infrared moving image). The display control unit (2112) displays the front image (H) acquired by the photographing unit side by side with the first moving image (G1) and the second moving image (G2). Further, the display control unit (2112) displays a first scanning line image (L1) representing the first scanning line (L1) and a second scanning line image (L2) representing the second scanning line (L2) as a front image. Display with (H).

  According to such a configuration, it is possible to easily grasp in which part of the eye to be examined the first scanning line and the second scanning line are set. That is, it is possible to easily grasp which part of the eye to be scanned is scanned. Furthermore, by displaying such information side by side on the first moving image and the second moving image, it is possible to observe a plurality of moving images obtained by the scan while grasping which part of the eye to be examined is actually scanned. Is possible.

  In the embodiment, the display control unit (2112) includes the first correspondence information indicating the correspondence between the first scanning line (L1) and the first moving image (G1), the second scanning line (L2), and the second moving image. Second correspondence information indicating the correspondence with (G2) can be displayed. There is a display color as an example of the first correspondence information and the second correspondence information. For example, the first scanning line image (L1) and the frame of the first moving image (G1) are displayed in the first color as the first correspondence information, and the second scanning line image (L2) is used as the second correspondence information. And the frame of the second moving image (G2) can be displayed in a second color different from the first color.

  According to such a configuration, it is possible to easily recognize the correspondence between two (or more) scanning lines and two (or more) moving images. In particular, by associating scanning lines with moving images using display colors, it is possible to intuitively grasp their correspondence.

  The configuration described above is merely an example for favorably implementing the present invention. Therefore, arbitrary modifications (omitted, replacement, addition, etc.) within the scope of the present invention can be made as appropriate. The configuration to be applied is selected according to the purpose, for example. In addition, depending on the configuration to be applied, a function and effect obvious to those skilled in the art and the function and effect described in this specification can be obtained.

DESCRIPTION OF SYMBOLS 1 Ophthalmology imaging apparatus 2 Fundus camera unit 100 OCT unit 200 Arithmetic control unit 210 Control part 211 Main control part 2111 Condition control part 2112 Display control part 220 Image formation part 230 Data processing part 231 Attention area specific | specification part 232 Position determination part 240 User interface 241 Display unit 242 Operation unit E Eye to be examined

Claims (6)

An ophthalmic imaging apparatus that acquires a cross-sectional image by scanning an eye to be examined using optical coherence tomography (OCT),
A data acquisition unit for acquiring data by executing a first scan along the first scan line in the eye to be examined and a second scan along a second scan line having a direction different from that of the first scan line;
The cross-sectional image based on the data acquired by the first scan is analyzed to identify the image region of the target region of the eye to be examined, and the cross-sectional image based on the data acquired by the second scan is analyzed to analyze the target region A specific part for specifying the image area of
A display control unit for displaying information on a display unit based on a position in the cross-sectional image of the image area specified by the specifying unit;
A specific part of the eye to be examined is specified from a cross-sectional image based on the data acquired by the first scan and / or a cross-sectional image based on the data acquired by the second scan, and a predetermined depth of the frame of the cross-sectional image A condition control unit that changes the optical path length of the OCT measurement light and / or the optical path length of the OCT reference light so that the specific part is arranged at a position ;
Each of the first scan line and the second scan line is a line segment,
The first scanning line and the second scanning line are perpendicular to each other and intersect each other at the center position.
An ophthalmologic photographing apparatus characterized by that . The data acquisition unit alternately executes the first scan and the second scan,
The display control unit causes the display unit to display a first moving image based on data sequentially acquired by the first scan and a second moving image based on data sequentially acquired by the second scan. The ophthalmologic photographing apparatus according to claim 1.   The display control unit displays the first moving image in a direction corresponding to the first scanning line and the second moving image in a direction corresponding to the second scanning line side by side. The ophthalmologic photographing apparatus according to 2.   The said display control part displays the cross-sectional image concerning the edge part of the said cross-sectional image in the said image area specified by the said specific part in the aspect different from another cross-sectional image, The Claims 1-3 characterized by the above-mentioned. The ophthalmologic photographing apparatus according to any one of the above.   The ophthalmic imaging according to claim 4, wherein the display control unit displays a cross-sectional image in which the image region is applied to at least one of an upper edge and a lower edge of the cross-sectional image in a manner different from other cross-sectional images. apparatus. The first scanning line and the second scanning line are set in a three-dimensional measurement range of the eye to be examined,
6. The display control unit according to claim 1, wherein the display control unit displays information based on a specific result by the specifying unit before performing optical coherence tomography of the entire three-dimensional measurement range. The ophthalmologic imaging apparatus according to any one of the above.