JP6279682B2 - Ophthalmic observation device - Google Patents

Description

  The present invention relates to an ophthalmologic observation apparatus that acquires an image of an eye to be examined.

  In recent years, optical coherence tomography (OCT), which forms an image representing the surface form and internal form of an object to be measured using a light beam from a laser light source or the like, has attracted attention. Since OCT has no invasiveness to the human body like X-ray CT, it is expected to be applied particularly in the medical field and the biological field. For example, in the field of ophthalmology, an apparatus for forming an image of the fundus oculi or cornea has been put into practical use.

  Patent Document 1 discloses an apparatus using a so-called “Fourier Domain OCT (Fourier Domain OCT)” technique. That is, this apparatus irradiates the object to be measured with a beam of low coherence light, superimposes the reflected light and the reference light to generate interference light, acquires the spectral intensity distribution of the interference light, and performs Fourier transform. By performing the conversion, the form of the object to be measured in the depth direction (z direction) is imaged. Further, this apparatus includes a galvanometer mirror that scans a light beam (signal light) in one direction (x direction) orthogonal to the z direction, thereby forming an image of a desired measurement target region of the object to be measured. It has become. An image formed by this apparatus is a two-dimensional tomographic image in the depth direction (z direction) along the scanning direction (x direction) of the light beam. Note that this technique is also called a spectral domain.

  In Patent Document 2, a plurality of two-dimensional tomographic images in the horizontal direction are formed by scanning (scanning) the signal light in the horizontal direction (x direction) and the vertical direction (y direction), and based on the plurality of tomographic images. A technique for acquiring and imaging three-dimensional tomographic information of a measurement range is disclosed. As this three-dimensional imaging, for example, a method of displaying a plurality of tomographic images side by side in a vertical direction (referred to as stack data or the like), volume data (voxel data) based on the stack data is rendered, and a three-dimensional image is rendered. There is a method of forming.

  Patent Documents 3 and 4 disclose other types of OCT apparatuses. In Patent Document 3, the wavelength of light irradiated to a measured object is scanned (wavelength sweep), and interference intensity obtained by superimposing reflected light of each wavelength and reference light is detected to detect spectral intensity distribution. And an OCT apparatus for imaging the form of an object to be measured by performing Fourier transform on the obtained image. Such an OCT apparatus is called a swept source type. The swept source type is a kind of Fourier domain type.

  In Patent Document 4, the traveling direction of light is obtained by irradiating the object to be measured with light having a predetermined beam diameter, and analyzing the component of interference light obtained by superimposing the reflected light and the reference light. An OCT apparatus for forming an image of an object to be measured in a cross-section orthogonal to is described. Such an OCT apparatus is called a full-field type or an en-face type.

  Patent Document 5 discloses a configuration in which OCT is applied to the ophthalmic field. Prior to the application of OCT, a fundus camera, a slit lamp, an SLO (Scanning Laser Ophthalmoscope), and the like were used as devices for observing the eye to be examined (for example, Patent Document 6, Patent Document 7, and Patent Document). 8). A fundus camera is a device that shoots the fundus by illuminating the subject's eye with illumination light and receiving the fundus reflection light. A slit lamp is a device that acquires an image of a cross-section of the cornea by cutting off a light section of the cornea using slit light. The SLO is an apparatus that images the fundus surface by scanning the fundus with laser light and detecting the reflected light with a highly sensitive element such as a photomultiplier tube. According to these apparatuses, an image (front image) obtained by photographing the fundus or anterior eye portion from the front can be obtained.

  An apparatus using OCT has an advantage over a fundus camera or the like in that it can acquire a high-definition image, and further can acquire a tomographic image or a three-dimensional image.

  As described above, an apparatus using OCT can be applied to observation of various parts of an eye to be examined, and can acquire high-definition images, and thus has been applied to diagnosis of various ophthalmic diseases.

JP 11-325849 A JP 2002-139421 A JP 2007-24677 A JP 2006-153838 A JP 2008-73099 A JP-A-9-276232 JP 2008-259544 A JP 2009-11811 A

  For example, in a conventional ophthalmic observation apparatus that can acquire both a front image and an OCT image of an eye to be examined, such as a fundus observation apparatus described in Patent Document 5, an optical system for acquiring a front image and an optical for OCT measurement are used. The system has a common focusing lens.

  On the other hand, the wavelength of light for front image acquisition (such as visible light) and the wavelength of light for OCT measurement (such as near-infrared light) are different, so that the optimum focus positions for the two images are different.

  Therefore, when the focusing lens is set to the optimum focus position (focus position) for acquiring the front image, the OCT measurement cannot be performed in the optimum focus state. On the other hand, when the focusing lens is set to the optimum focus position for OCT measurement, the front image cannot be obtained in the optimum focus state.

  An object of the present invention is to provide a technique capable of performing both acquisition of a front image of an eye to be examined and OCT measurement in a suitable focus state.

  In order to achieve the above object, the invention described in claim 1 includes a first focusing lens, and includes a photographing optical system that performs photographing for acquiring a front image of the eye to be examined, and a second focusing lens. A measurement optical system that performs optical coherence tomography measurement for obtaining a tomographic image of the eye to be examined, and an optical path of the imaging optical system at a position closer to the eye to be examined than the first focusing lens and the second focusing lens And an optical path of the measurement optical system, a first drive unit for moving the first focusing lens along the optical axis of the photographing optical system, and an optical axis of the measurement optical system A second driving unit for moving the second focusing lens along the axis, and a control unit for controlling the first driving unit and the second driving unit, respectively. Coherence tomography for acquiring tomographic images of the fundus of the eye A projection optical system that performs measurement and projects a focus index indicating the in-focus state of the imaging optical system with respect to the fundus; and an intensity acquisition unit that acquires the intensity of the interference signal obtained by the measurement optical system. Then, after the photographing optical system and the measurement optical system are focused on the basis of the focus index, the control unit controls the second drive unit based on the intensity acquired by the intensity acquisition unit. This is an ophthalmic observation apparatus.

  According to this invention, it is possible to perform both acquisition of the front image of the eye to be examined and OCT measurement in a suitable focus state.

It is a schematic diagram showing an example of composition of an ophthalmology observation device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology observation device concerning an embodiment. It is a schematic block diagram showing an example of composition of an ophthalmic observation device concerning an embodiment. It is the schematic for demonstrating an example of a structure of the ophthalmologic observation apparatus which concerns on embodiment. It is a flowchart showing the operation example of the ophthalmic observation apparatus which concerns on embodiment. It is a schematic block diagram showing an example of composition of an ophthalmic observation device concerning an embodiment. It is a flowchart showing the operation example of the ophthalmic observation apparatus which concerns on embodiment. It is a schematic block diagram showing an example of composition of an ophthalmic observation device concerning an embodiment. It is a flowchart showing the operation example of the ophthalmic observation apparatus which concerns on embodiment. It is a flowchart showing the operation example of the ophthalmic observation apparatus which concerns on embodiment. It is a schematic block diagram showing an example of composition of an ophthalmic observation device concerning an embodiment. It is a flowchart showing the operation example of the ophthalmic observation apparatus which concerns on embodiment.

  An example of an embodiment of an ophthalmologic observation apparatus will be described in detail with reference to the drawings. The ophthalmic observation apparatus according to the embodiment has a function of acquiring a tomographic image or a three-dimensional image of the eye to be examined (fundus, anterior eye portion, etc.) using OCT and a function of capturing a front image by photographing the eye to be examined. Have. In this specification, an image acquired by OCT may be referred to as an OCT image. In addition, a measurement operation for forming an OCT image may be referred to as optical coherence tomography measurement (OCT measurement). In addition, it is possible to use suitably the description content of the literature described in this specification as the content of the following embodiment.

  In the following embodiment, a configuration to which Fourier domain type OCT is applied will be described in detail. In particular, the ophthalmic observation apparatus described below can acquire an OCT image using the spectral domain OCT technique, as in the apparatus disclosed in Patent Document 5. The configuration according to the present invention can be applied to an ophthalmic observation apparatus using a type other than the spectral domain, for example, a swept source OCT technique. In the following embodiments, an apparatus combining an OCT apparatus and a fundus camera will be described. However, it is also possible to combine an OCT apparatus with an ophthalmic imaging apparatus other than the fundus camera, for example, an SLO, a slit lamp, an ophthalmic surgical microscope, or the like. is there.

<First Embodiment>
[Constitution]
As shown in FIGS. 1 and 2, the ophthalmologic observation apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The fundus camera unit 2 includes an optical system that is substantially the same as a conventional fundus camera. The OCT unit 100 is provided with an optical system for acquiring an OCT image of the fundus. 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 acquiring a front 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 illumination optical system 10 and the photographic optical system 30 function as an example of a “photographic optical system”.

  The observation light source 11 of the illumination optical system 10 is constituted by a halogen lamp, for example. 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. An LED (Light Emitting Diode) can also be used as the observation light source.

  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 39A, 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 optical system that illuminates the eye E with the observation illumination light and detects the reflected light is an example of an infrared imaging optical system.

  The imaging light source 15 is constituted by, for example, a xenon lamp. 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 measurement.

  A part of the light output from the LCD 39 is reflected by the half mirror 39A, 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 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, a position for acquiring an image centered on the macular portion of the fundus oculi Ef, or a position for acquiring an image centered on the optic disc as in the case of a conventional fundus camera 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 fundus oculi Ef.

  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 39A, 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 combines the optical path for fundus imaging and the optical path for OCT measurement. The dichroic mirror 46 reflects light in a wavelength band used for OCT measurement and transmits light for fundus photographing. The dichroic mirror 46 is an example of an optical path combining unit. In the optical path for OCT measurement, a collimator lens unit 40, an optical path length changing unit 41, a galvano scanner 42, a focusing lens 43, a mirror 44, and a relay lens 45 are provided in this order from the OCT unit 100 side. ing. The optical system constituting the optical path for OCT measurement and the optical system included in the OCT unit 100 are examples of the measurement optical system.

  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 measurement. 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 galvano scanner 42 changes the traveling direction of light (signal light LS) passing through the optical path for OCT measurement. Thereby, the fundus oculi Ef can be scanned with the signal light LS. The galvano scanner 42 includes, for example, a galvano mirror that scans the signal light LS in the x direction, a galvano mirror that scans in the y direction, and a mechanism that drives these independently. Thereby, the signal 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 will be described with reference to FIG. The OCT unit 100 is provided with an optical system for acquiring an OCT image of the fundus oculi Ef. This optical system has the same configuration as a conventional spectral domain type OCT apparatus. That is, this optical system divides low-coherence light into reference light and signal light, and generates interference light by causing interference between the signal light passing through the fundus oculi Ef and the reference light passing through the reference optical path. It is configured to detect spectral components. This detection result (detection signal) is sent to the arithmetic control unit 200.

  In the case of a swept source type OCT apparatus, a wavelength swept light source is provided instead of a light source that outputs a low coherence light source, and an optical member that spectrally decomposes interference light is not provided. In general, for the configuration of the OCT unit 100, a known technique according to the type of optical coherence tomography can be arbitrarily applied.

  The light source unit 101 outputs a broadband low-coherence light L0. The low coherence light L0 includes, for example, a near-infrared wavelength band (about 800 nm to 900 nm) and has a temporal coherence length of about several tens of micrometers. Note that near-infrared light having a wavelength band that cannot be visually recognized by the human eye, for example, a center wavelength of about 1040 to 1060 nm, may be used as the low-coherence light L0.

  The light source unit 101 includes a light output device such as a super luminescent diode (SLD), an LED, or an SOA (Semiconductor Optical Amplifier).

  The low-coherence light L0 output from the light source unit 101 is guided to the fiber coupler 103 by the optical fiber 102 and split into the signal light LS and the reference light LR.

  The reference light LR is guided by the optical fiber 104 and reaches the optical attenuator (attenuator) 105. The optical attenuator 105 automatically adjusts the amount of the reference light LR guided to the optical fiber 104 under the control of the arithmetic control unit 200 using a known technique. The reference light LR whose light amount has been adjusted by the optical attenuator 105 is guided by the optical fiber 104 and reaches the polarization adjuster (polarization controller) 106. The polarization adjuster 106 is, for example, a device that adjusts the polarization state of the reference light LR guided in the optical fiber 104 by applying a stress from the outside to the optical fiber 104 in a loop shape. The configuration of the polarization adjuster 106 is not limited to this, and any known technique can be used. The reference light LR whose polarization state is adjusted by the polarization adjuster 106 reaches the fiber coupler 109.

  The signal light LS generated by the fiber coupler 103 is guided by the optical fiber 107 and converted into a parallel light beam by the collimator lens unit 40. Further, the signal light LS reaches the dichroic mirror 46 via the optical path length changing unit 41, the galvano scanner 42, the focusing lens 43, the mirror 44, and the relay lens 45. The signal light LS is reflected by the dichroic mirror 46, is refracted by the objective lens 22, and is applied to the fundus oculi Ef. The signal light LS is scattered (including reflection) at various depth positions of the fundus oculi Ef. The backscattered light of the signal light LS from the fundus oculi Ef travels in the same direction as the forward path in the reverse direction, is guided to the fiber coupler 103, and reaches the fiber coupler 109 via the optical fiber 108.

  The fiber coupler 109 causes the backscattered light of the signal light LS to interfere with the reference light LR that has passed through the optical fiber 104. The interference light LC generated thereby is guided by the optical fiber 110 and emitted from the emission end 111. Further, the interference light LC is converted into a parallel light beam by the collimator lens 112, dispersed (spectral decomposition) by the diffraction grating 113, condensed by the condenser lens 114, and projected onto the light receiving surface of the CCD image sensor 115. Although the diffraction grating 113 shown in FIG. 2 is a transmission type, other types of spectroscopic elements such as a reflection type diffraction grating may be used.

  The CCD image sensor 115 is a line sensor, for example, and detects each spectral component of the split interference light LC and converts it into electric charges. The CCD image sensor 115 accumulates this electric charge, generates a detection signal, and sends it to the arithmetic control unit 200.

  In this embodiment, a Michelson type interferometer is employed, but any type of interferometer such as a Mach-Zehnder type can be appropriately employed. Further, in place of the CCD image sensor, another form of image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor can be used.

[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 CCD image sensor 115 and forms an OCT image of the fundus oculi Ef. The arithmetic processing for this is the same as that of a conventional spectral domain 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 fundus oculi Ef 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, Movement control, movement control of the focus optical system 60, movement control of the optical path length changing unit 41, operation control of the galvano scanner 42, and the like are performed.

  As control of the OCT unit 100, the arithmetic control unit 200 performs operation control of the light source unit 101, operation control of the optical attenuator 105, operation control of the polarization adjuster 106, operation control of the CCD image sensor 115, and the like.

  The arithmetic control unit 200 includes, for example, a microprocessor, a RAM, a ROM, a hard disk drive, a communication interface, etc., as in a conventional computer. A computer program for controlling the ophthalmic observation 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 observation apparatus 1 will be described with reference to FIG.

(Control part)
The control system of the ophthalmologic observation apparatus 1 is configured around the control unit 210. The control unit 210 includes, for example, the aforementioned microprocessor, RAM, ROM, hard disk drive, communication interface, and the like. The control unit 210 includes a main control unit 211, a storage unit 212, and a target position acquisition unit 213.

(Main control unit)
The main control unit 211 performs the various controls described above. In particular, the main control unit 211 includes the focusing drive units 31A and 43A, the optical system drive unit 60A, the LED 61, the reflector driving unit 67A, the CCDs 35 and 38, the optical path length changing unit 41, and the galvano scanner 42 of the fundus camera unit 2. Control. The main control unit 211 controls the light source unit 101, the optical attenuator 105, the polarization adjuster 106, and the CCD image sensor (sometimes simply referred to as a CCD) 115 of the OCT unit 100.

  The focusing drive unit 31A moves the focusing lens 31 along the optical axis under the control of the main control unit 211. Thereby, the focus position of the photographic optical system 30 is changed. The focusing drive unit 31 </ b> A includes an actuator such as a pulse motor and a mechanism that transmits a driving force generated by the actuator to the focusing lens 31. The focusing lens 31 is an example of a first focusing lens. The focusing drive unit 31A is an example of a first drive unit.

  Under the control of the main control unit 211, the focusing drive unit 43A moves the focusing lens 43 along the optical axis. Thereby, the focus position of the measurement optical system for OCT measurement is changed. The in-focus position of the measurement optical system defines the amount of signal light LS incident on the optical fiber 107 via the collimator lens unit 40. That is, the optimum focusing position of the measurement optical system is realized by arranging the focusing lens 43 at a position where the fiber end of the optical fiber 107 on the collimator lens unit 40 side and the fundus oculi Ef are optically conjugate. The The focusing drive unit 43 </ b> A includes an actuator such as a pulse motor and a mechanism that transmits a driving force generated by the actuator to the focusing lens 43.

  The optical system drive unit 60A moves the focus optical system 60 along the optical axis under the control of the main control unit 211. Thereby, the projection mode of the split indicator on the fundus oculi Ef is changed. The optical system driving unit 60 </ b> A includes an actuator such as a pulse motor and a mechanism that transmits a driving force generated by the actuator to the focus optical system 60. The focus optical system 60 is configured as a unit, for example. The focus optical system 60 projects a split index (focus index) indicating the focus state (focus state) of the photographing optical system 30 with respect to the fundus oculi Ef onto the fundus oculi Ef, and is an example of a projection optical system.

  Under the control of the main control unit 211, the reflection bar driving unit 67A inserts and removes the reflection bar 67 with respect to the optical path. The reflector 67 is inserted into the optical path when projecting the split index, that is, at the start of focus adjustment, and is retracted from the optical path at the end of focus adjustment. The reflector driving unit 67A includes an actuator such as a solenoid and a mechanism for transmitting the driving force generated by the actuator to the reflector 67.

  The main control unit 211 controls a driving mechanism (not shown) to move the fundus camera unit 2 three-dimensionally. This control is used in alignment and tracking. Tracking is to move the apparatus optical system in accordance with the eye movement of the eye E. When tracking is performed, alignment and focusing are performed in advance. Tracking is a function of maintaining a suitable positional relationship in which the alignment and focus are achieved by causing the position of the apparatus optical system to follow the eye movement.

  Further, the main control unit 211 performs processing for writing data into the storage unit 212 and processing for reading data from the storage unit 212.

(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 observation apparatus 1.

  In the storage unit 212 of this embodiment, correspondence information 212a is stored in advance. Correspondence information 212 a corresponds to first correspondence information in which an eye refractive power value (diopter) and the position of the focusing lens 31 are associated, and an eye refractive power value (diopter) and the position of the focusing lens 43. And the attached second correspondence information. It should be noted that the first correspondence information and the second correspondence information may be individual information or information combined into one. The correspondence information 212a may be information in which discrete values such as table information are associated with each other, or information in which continuous values such as graph information are associated with each other. May be.

(Target position acquisition unit)
The target position acquisition unit 213 acquires the target positions of the focusing lens 31 and the focusing lens 43 based on the refractive power of the eye E. The target position acquisition unit 213 is an example of a first target position acquisition unit.

  The target position is position information that is a movement target of the focusing lens 31 (or the focusing lens 43). This position information indicates a position along the optical axis of the optical system provided with the focusing lens 31 (or the focusing lens 43). This position information may be any form of information. For example, this position information may be information indicating the position itself on the optical axis, or the content of the control signal for moving the focusing lens 31 (or the focusing lens 43) (for example, the number of pulses of the signal sent to the pulse motor) ) May be used.

  The refractive power of the eye E is acquired by an arbitrary refractive power acquisition unit. For example, when the refractive power measurement of the eye E is performed in the past, the refractive power acquisition unit (the control unit 210 or the like) can be configured to read the value of the eye refractive power recorded in the electronic medical record or the like. Further, although details will be described later, it is also possible to configure so that the refractive power of the eye E is acquired by the analysis unit 231 of the image processing unit 230.

  The target position acquisition unit 213 acquires the target positions of the focusing lens 31 and the focusing lens 43 based on the refractive power acquired by the refractive power acquisition unit and the correspondence information 212a. That is, the target position acquisition unit 213 acquires the position of the focusing lens 31 associated with the eye refractive power value acquired by the refractive power acquisition unit with reference to the first correspondence information, and focuses this The target position of the lens 31 is set. Similarly, the target position acquisition unit 213 acquires the position of the focusing lens 43 associated with the eye refractive power value acquired by the refractive power acquisition unit with reference to the second correspondence information, and aligns this. The target position of the focal lens 43 is set.

(Image forming part)
The image forming unit 220 forms tomographic image data of the fundus oculi Ef based on the detection signal from the CCD image sensor 115. This process includes processes such as noise removal (noise reduction), filter processing, dispersion compensation, and FFT (Fast Fourier Transform) as in the conventional spectral domain type optical coherence tomography. In the case of another type of OCT apparatus, the image forming unit 220 executes a known process corresponding to the type.

  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.

(Image processing unit)
The image processing unit 230 performs various types of image processing and analysis processing on the image formed by the image forming unit 220. For example, the image processing unit 230 executes various correction processes such as image brightness correction. The image 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 image processing unit 230 executes known image processing such as interpolation processing for interpolating pixels between tomographic images to form image data of a three-dimensional image of the fundus oculi Ef. Note that the image data of a three-dimensional image means image data in which pixel positions are defined by a three-dimensional coordinate system. As image data of a three-dimensional image, there is image data composed of voxels arranged three-dimensionally. This image data is called volume data or voxel data. When displaying an image based on volume data, the image processing unit 230 performs rendering processing (volume rendering, MIP (Maximum Intensity Projection), etc.) on the volume data, and views the image from a specific gaze direction. Image data of a pseudo three-dimensional image is formed. The pseudo three-dimensional image is displayed on the display unit 240A.

  It is also possible to form stack data of a plurality of tomographic images as image data of a three-dimensional image. The stack data is image data obtained by three-dimensionally arranging a plurality of tomographic images obtained along a plurality of scanning lines based on the positional relationship of the scanning lines. That is, stack data is image data obtained by expressing a plurality of tomographic images originally defined by individual two-dimensional coordinate systems by one three-dimensional coordinate system (that is, by embedding them in one three-dimensional space). is there.

(Analysis Department)
The image processing unit 230 has an analysis unit 231. The analysis unit 231 obtains the refractive power of the eye E by analyzing a front image obtained by photographing the fundus oculi Ef on which the split index is projected with an infrared imaging optical system. This front image is, for example, the aforementioned observation image.

  An example of the observation image is shown in FIG. In the observation image G shown in FIG. 4, a pair of split index images (split index images) B1 and B2 are drawn together with the form of the fundus oculi Ef. Reference symbol A is a shadow (reflecting rod image) of the reflecting rod 67 arranged in the optical path of the illumination optical system 10. When the focus of the photographing optical system 30 is appropriate, that is, when the focusing lens 31 is disposed at an appropriate position, the split index images B1 and B2 are drawn in a straight line in the vertical direction in FIG. On the other hand, when the focus of the photographing optical system 30 is not appropriate, the split index images B1 and B2 are drawn shifted in the left-right direction in FIG. The shift direction and shift amount of the split index images B1 and B2 correspond to the shift direction and shift amount from the proper focus state. This focus shift corresponds to the refractive power of the eye E.

  The analysis unit 231 previously stores information (index image / eye refractive power correspondence information) in which the shift direction and shift amount of the split index images B1 and B2 are associated with the value of the eye refractive power. The analysis unit 231 acquires the shift information (shift direction and shift amount) of the split index images B1 and B2 drawn on the observation image by analyzing the observation image (the still image constituting the observation image). Further, the analysis unit 231 obtains the eye refractive power corresponding to the acquired deviation information based on the index image / eye refractive power correspondence information. The obtained eye refractive power value is used as the refractive power of the eye E to be examined.

  Information on the refractive power of the eye E acquired by the analysis unit 231 is sent to the target position acquisition unit 213. The target position acquisition unit 213 acquires the target position of the focusing lens 31 and the target position of the focusing lens 43 based on the refractive power information and the correspondence information 212a. This process is executed as described above.

  The image processing unit 230 that functions as described above includes, for example, the aforementioned microprocessor, RAM, ROM, hard disk drive, 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 240A and an operation unit 240B. The display unit 240A includes the display device of the arithmetic control unit 200 and the display device 3 described above. The operation unit 240B includes the operation device of the arithmetic control unit 200 described above. The operation unit 240B may include various buttons and keys provided on the housing of the ophthalmologic observation apparatus 1 or outside. For example, when the fundus camera unit 2 has a housing similar to that of a conventional fundus camera, the operation unit 240B may include a joystick, an operation panel, or the like provided on the housing. The display unit 240 </ b> A may include various display devices such as a touch panel provided on the housing of the fundus camera unit 2.

  The display unit 240A and the operation unit 240B 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 240B includes the touch panel and a computer program. The operation content for the operation unit 240B is input to the control unit 210 as an electrical signal. Further, operations and information input may be performed using a graphical user interface (GUI) displayed on the display unit 240A and the operation unit 240B.

[Signal light scanning and OCT images]
Here, the scanning of the signal light LS and the OCT image will be described.

  Examples of the scan mode of the signal light LS by the ophthalmologic observation apparatus 1 include a horizontal scan, a vertical scan, a cross scan, a radiation scan, a circular scan, a concentric scan, and a spiral (vortex) scan. These scan modes are selectively used as appropriate in consideration of the observation site of the fundus, the analysis target (such as retinal thickness), the time required for scanning, the precision of scanning, and the like.

  The horizontal scan scans the signal light LS in the horizontal direction (x direction). The horizontal scan also includes an aspect in which the signal light LS is scanned along a plurality of horizontal scanning lines arranged in the vertical direction (y direction). In this aspect, it is possible to arbitrarily set the scanning line interval. Further, the above-described three-dimensional image can be formed by sufficiently narrowing the interval between adjacent scanning lines (three-dimensional scanning). The same applies to the vertical scan.

  In the cross scan, the signal light LS is scanned along a cross-shaped trajectory composed of two linear trajectories (straight trajectories) orthogonal to each other. In the radiation scan, the signal light LS is scanned along a radial trajectory composed of a plurality of linear trajectories arranged at a predetermined angle. The cross scan is an example of a radiation scan.

  In the circle scan, the signal light LS is scanned along a circular locus. In the concentric scan, the signal light LS is scanned along a plurality of circular trajectories arranged concentrically around a predetermined center position. A circle scan is an example of a concentric scan. In the helical scan, the signal light LS is scanned along a spiral (spiral) trajectory while gradually reducing (or increasing) the radius of rotation.

  Since the galvano scanner 42 is configured to scan the signal light LS in directions orthogonal to each other, it can independently scan the signal light LS in the x direction and the y direction, respectively. Further, by simultaneously controlling the directions of the two galvanometer mirrors included in the galvano scanner 42, the signal light LS can be scanned along an arbitrary locus on the xy plane. Thereby, various scan modes as described above can be realized.

  By scanning the signal light LS in the above-described manner, a tomographic image on a plane stretched by the direction along the scanning line (scanning trajectory) and the fundus depth direction (z direction) can be acquired. In addition, the above-described three-dimensional image can be acquired particularly when the scanning line interval is narrow.

  A region on the fundus oculi Ef to be scanned with the signal light LS as described above, that is, a region on the fundus oculi Ef to be subjected to OCT measurement is referred to as a scanning region. The scanning area in the three-dimensional scan is a rectangular area in which a plurality of horizontal scans are arranged. The scanning area in the concentric scan is a disk-shaped area surrounded by the locus of the circular scan with the maximum diameter. In addition, the scanning area in the radial scan is a disk-shaped (or polygonal) area connecting both end positions of each scan line.

[Operation]
The operation of the ophthalmologic observation apparatus 1 will be described. FIG. 5 shows an example of the operation of the ophthalmologic observation apparatus 1.

(S1: Start of observation image acquisition)
First, an observation image of the fundus oculi Ef is obtained by continuously illuminating the fundus oculi Ef with observation illumination light. The observation image is a near-infrared moving image obtained in real time until the continuous illumination ends. At this time, a fixation target by the LCD 39 is projected onto the eye E.

(S2: Perform alignment)
Further, an alignment index by the alignment optical system 50 and a split index by the focus optical system 60 are projected onto the eye E to be examined. An alignment index image (not shown) and split index images B1 and B2 shown in FIG. 4 are drawn on the observation image. The user or the control unit 210 performs alignment (manual alignment or automatic alignment) using the alignment index.

(S3: Obtain eye refractive power)
The analysis unit 231 obtains the refractive power of the eye E by analyzing the observation image (the frame thereof). More specifically, the analysis unit 231 obtains the refractive power of the eye E based on the positions of the split index images B1 and B2 drawn on the observation image.

(S4: Find the target position of the focusing lens)
Based on the refractive power of the eye E acquired in step 3 and the correspondence information 212a stored in advance in the storage unit 212, the target position acquisition unit 213 sets the target position (first position) of the focusing lens 31 of the imaging optical system 30. 1 target position) and the target position (second target position) of the focusing lens 43 of the OCT measurement optical system (measurement optical system).

(S5: Move the focusing lens to the target position)
The main control unit 211 controls the focusing drive unit 31 </ b> A so as to move the focusing lens 31 to the first target position acquired in step 4. Further, the main control unit 211 controls the focusing drive unit 43A so as to move the focusing lens 43 to the second target position acquired in Step 4. The main control unit 211 may perform these two controls in parallel, or may perform the other control after performing one control. Furthermore, the main control unit 211 can recognize the current positions of the focusing lenses 31 and 43. For example, a position sensor that detects the positions of the focusing lenses 31 and 43 can be provided. In addition, a control history (for example, contents of pulse signals transmitted to the focusing drive units 31A and 43A between the state where the focusing lenses 31 and 43 are arranged at a predetermined initial position to the present) is recorded. It is also possible to apply a configuration. The main control unit 211 transmits a control signal for moving the focusing lens 31 from the current position to the first target position to the focusing driving unit 31A, and moves the focusing lens 43 from the current position to the second target position. Control signal for transmitting to the in-focus driving unit 43A. Thereby, the focusing lens 31 is moved to the first target position, and the focusing lens 43 is moved to the second target position.

(S6: A tomogram is acquired by performing OCT measurement of the fundus)
The main control unit 211 controls the OCT unit 100, the optical path length changing unit 41, the galvano scanner 42, and the like to perform OCT measurement of the fundus oculi Ef. Data acquired by OCT measurement is sent from the CCD 115 to the image forming unit 220 as a detection signal. The image forming unit 220 forms a tomographic image of the fundus oculi Ef based on this detection signal. The main controller 211 displays the formed tomographic image on the display 240A. The main control unit 211 stores the formed tomographic image in the storage unit 212.

(S7: The fundus is photographed to obtain a photographed image)
The main controller 211 controls the illumination optical system 10 (such as the imaging light source 15) and the imaging optical system 30 to acquire a captured image of the fundus oculi Ef. The main control unit 211 causes the display unit 240A to display the acquired captured image. In addition, the main control unit 211 causes the storage unit 212 to store the acquired captured image. This is the end of this operation example.

[Action / Effect]
The operation and effect of the ophthalmologic observation apparatus 1 will be described.

  The ophthalmologic observation apparatus 1 of this embodiment includes a photographing optical system, a measurement optical system, an optical path synthesis unit, a first drive unit, a second drive unit, and a control unit. The imaging optical system performs imaging for acquiring a front image of the eye E and includes a first focusing lens. In this embodiment, the photographing optical system includes the illumination optical system 10 and the photographing optical system 30, and the focusing lens 31 corresponds to the first focusing lens. The measurement optical system performs optical coherence tomography measurement (OCT measurement) for acquiring a tomographic image of the eye E, and includes a second focusing lens. In this embodiment, the measurement optical system includes an optical system stored in the OCT unit 100 and an optical system that forms an optical path from the collimator lens unit 40 to the objective lens 22, and the focusing lens 43 is in the second focusing state. Corresponds to the lens. The optical path combining unit combines the optical path of the imaging optical system and the optical path of the measurement optical system at a position closer to the subject's eye than the first focusing lens and the second focusing lens. “Position on the eye side relative to the focusing lens” indicates a position on the eye side relative to the focusing lens in the optical path of each optical system. In this embodiment, the dichroic mirror 46 corresponds to an optical path combining unit. As can be seen from the configuration of the optical path combining unit, the first focusing lens and the second focusing lens are separate optical elements. The first drive unit is for moving the first focusing lens along the optical axis of the photographing optical system. In this embodiment, the focusing drive unit 31A corresponds to the first drive unit. The second drive unit is for moving the second focusing lens along the optical axis of the measurement optical system. In this embodiment, the focusing drive unit 43A corresponds to the second drive unit. The control unit controls the first driving unit and the second driving unit, respectively. In this embodiment, the control unit 210 corresponds to the control unit.

  According to such an ophthalmologic observation apparatus 1, each of the photographing optical system and the measurement optical system has the focusing lens individually, and these focusing lenses can be individually controlled. Therefore, it is possible to arrange the first focusing lens at the optimum focus position for acquiring the front image and to arrange the second focusing lens at the optimum focus position for OCT measurement. Therefore, it is possible to perform both the acquisition of the front image of the eye E and the OCT measurement in a suitable focus state.

  In this embodiment, the imaging optical system performs imaging for acquiring a front image of the fundus oculi Ef, and the measurement optical system performs optical coherence tomography measurement for acquiring a tomographic image of the fundus oculi Ef. Furthermore, the ophthalmologic observation apparatus 1 according to this embodiment includes a refractive power acquisition unit that acquires the refractive power of the eye E to be examined. The control unit 210 also acquires a first target position acquisition unit (target position acquisition unit 213) that acquires target positions of the first focusing lens and the second focusing lens based on the refractive power acquired by the refractive power acquisition unit. )including. Then, the control unit 210 controls the first driving unit so as to move the first focusing lens to the first target position acquired by the first target position acquisition unit, and sets the second focusing position to the second target position. The second drive unit is controlled to move the focal lens. In this embodiment, both the movement control of the first focusing lens and the movement control of the second focusing lens are performed, but only one of the movement controls may be performed. In that case, the other movement control can be performed by an arbitrary method.

  According to such an embodiment, it is possible to perform both acquisition of a front image of the fundus oculi Ef and OCT measurement in a suitable focus state. It is also possible to automatically control the movement of the focusing lens. Furthermore, since this movement control can be performed according to the refractive power of the eye E, focus adjustment can be performed with high accuracy.

  The process for acquiring the refractive power of the eye E can be performed as follows, for example. It is assumed that the imaging optical system includes an infrared imaging optical system that performs imaging of the fundus using infrared light. In this embodiment, the infrared imaging optical system includes an optical system that irradiates the fundus oculi with observation illumination light from the observation light source 11, and an optical system that detects fundus reflection light of the observation illumination light with the CCD image sensor 35. . The refractive power acquisition unit includes a projection optical system and an analysis unit. The projection optical system projects a focus index indicating the focus state of the photographing optical system with respect to the fundus oculi Ef onto the fundus oculi Ef. In this embodiment, the projection optical system includes a focus optical system 60, and the split index corresponds to the focus index. The analysis unit 231 obtains the refractive power of the eye E by analyzing the front image obtained by photographing the fundus oculi Ef on which the focus index is projected with the infrared photographing optical system.

  According to such an embodiment, since the refractive power can be acquired by actually measuring the eye E, focus adjustment can be performed with high accuracy.

  The process of acquiring the target position of the focusing lens can be performed as follows, for example. First, the control unit 210 stores in advance correspondence information 212a in which the value of the eye refractive power and the position of the focusing lens are associated with each other. The correspondence information 212a is associated with the first correspondence information in which the value of the eye refractive power is associated with the position of the first focusing lens, and the value of the eye refractive power is associated with the position of the second focusing lens. Second correspondence information is included. The first target position acquisition unit (target position acquisition unit 213), based on the refractive power acquired by the refractive power acquisition unit, the first correspondence information, and the second correspondence information, the first focusing lens and the second focusing lens. Get each target position. More specifically, the first target position acquisition unit acquires the target position of the first focusing lens based on the refractive power acquired by the refractive power acquisition unit and the first correspondence information. The target position of the second focusing lens is acquired based on the two correspondence information.

  According to such an embodiment, it is possible to obtain the target positions of both focusing lenses 31 and 43 based on the refractive power of the eye E to be examined and the correspondence information 212a and to adjust the focus of both optical systems. is there. Therefore, it is possible to perform both the acquisition of the front image of the eye E and the OCT measurement in a suitable focus state.

<Second Embodiment>
In this embodiment, an ophthalmologic observation apparatus configured to perform focusing for acquiring a front image using a focusing result in OCT measurement will be described. For example, in the examination of the fundus, taking into account the miosis of the eye to be examined, imaging with visible light is generally performed after OCT measurement. This embodiment is effective in the inspection performed in such a flow.

[Constitution]
The ophthalmic observation apparatus of this embodiment has the same overall configuration and optical system configuration as those of the first embodiment. The configuration of the control system is almost the same as that of the first embodiment. Hereinafter, the same components as those in the first embodiment will be described using the same reference numerals.

  A configuration example of the control system of the ophthalmologic observation apparatus of this embodiment is shown in FIG. In this embodiment, a target position acquisition unit 214 is provided instead of the target position acquisition unit 213 of the first embodiment. Further, the correspondence information 212 a does not need to be stored in the storage unit 212, and the analysis unit 231 does not need to be provided in the image processing unit 230. Hereinafter, these differences will be mainly described.

  The target position acquisition unit 214 acquires the target position of the focusing lens 31 of the photographing optical system 30 based on the position of the focusing lens 43 of the measurement optical system when the OCT measurement is performed. The target position acquisition unit 214 is an example of a second target position acquisition unit.

  An example of processing executed by the target position acquisition unit 214 will be described. Prior to performing OCT measurement, focus adjustment for OCT measurement is performed. The focus adjustment may be performed using an infrared fundus image (observation image) and a split index as in the first embodiment, but detailed adjustment using an OCT image can be further performed. For example, by repeatedly performing OCT measurement on substantially the same cross section of the fundus oculi Ef, a moving image (OCT moving image) of the cross section can be acquired. The frame rate of this OCT moving image corresponds to the repetition frequency of OCT measurement.

  By displaying the OCT moving image on the display unit 240A, the user can manually perform focus adjustment.

  Further, a technique is known in which an ophthalmic observation apparatus automatically performs focus adjustment by analyzing an OCT moving image (a still image constituting the OCT moving image). As an example of this analysis processing, first, the image processing unit 230 analyzes a pixel value (luminance value) of a still image constituting an OCT moving image to identify a region with high image quality (high image quality region), and determines the depth of the frame. The current focus position is specified based on the position (z coordinate) of the high quality area in the vertical direction (z direction). Further, when the tissue (fundus surface, retinal pigment epithelium, choroid, etc.) to be focused has already been determined, the image processing unit 230 identifies a region (target region) corresponding to the tissue in the still image. To do. Further, the target area may be designated by the user. The image processing unit 230 obtains the position (z coordinate) of the target area in the depth direction (z direction) of the frame. The main control unit 211 generates a control signal for changing the current focus position of the measurement optical system to a focus position corresponding to the target area, and sends the control signal to the focusing drive unit 43A. Accordingly, the focusing lens 43 is disposed at a position corresponding to the focus position corresponding to the target area.

  Here, based on the configuration of the measurement optical system, the position in the depth direction (z direction) of the frame and the position of the focusing lens 43 of the measurement optical system can be associated in advance. Furthermore, it is possible to provide a function of correcting the association in consideration of the refractive power of the eye E to be examined.

  Further, the fundus oculi Ef drawn as an OCT moving image by eye movement or pulsation moves in the frame. The optical path length changing unit 41 is controlled so as to follow the movement of the image, and the image of the fundus oculi Ef is moved in the frame. There is also known a technique for retaining the predetermined position. The focus adjustment using the OCT image is not limited to that described above, and any method can be used.

  The target position acquisition unit 214 acquires the target position of the focusing lens 31 of the photographing optical system 30 based on the position of the focusing lens 43 set by the focus adjustment using the OCT image as described above.

  An example of this processing will be described. Information in which the position of the focusing lens 31 and the position of the focusing lens 43 are associated with each other is stored in the storage unit 212 in advance, and the position of the focusing lens 43 applied in the OCT measurement by referring to this information. It is possible to obtain the position of the focusing lens 31 corresponding to. Here, for example, as in the first embodiment, this information can be created using the value of the eye refractive power as a medium. This information can also be created with reference to the configuration of the imaging optical system and the measurement optical system, the difference between the wavelength of light used for fundus imaging and the wavelength of light used for OCT measurement, and the like. In addition, when the refractive power of the eye E is known, this information can be created or corrected based on the value of the eye refractive power. In addition, the process which calculates | requires the position of the focusing lens 31 from the position of the focusing lens 43 in OCT measurement is not limited to this, The target position acquisition part 214 can perform the said process with arbitrary methods.

  The main control unit 211 controls the focusing drive unit 31A so as to move the focusing lens 31 to the target position acquired by the target position acquisition unit 214.

[Operation]
The operation of the ophthalmologic observation apparatus according to this embodiment will be described. FIG. 7 shows an example of the operation of the ophthalmologic observation apparatus.

(S11: Start obtaining observation images)
As in the first embodiment, acquisition of an observation image is started, and fixation of the eye E is performed.

(S12: Perform alignment and focus adjustment)
Similar to the first embodiment, the alignment index and the split index are projected onto the eye E to be examined. Then, alignment using the alignment index and focus adjustment using the split index are executed. This focus adjustment is performed for both the photographing optical system and the measurement optical system.

(S13: Start OCT measurement)
The main control unit 211 controls the OCT unit 100, the optical path length changing unit 41, the galvano scanner 42, and the like, and starts OCT measurement of the fundus oculi Ef. This OCT measurement is repeatedly performed on substantially the same cross section of the fundus oculi Ef. That is, this OCT measurement is performed in an operation mode for acquiring an OCT moving image.

(S14: Perform focus adjustment using OCT moving image)
The user or the ophthalmologic observation apparatus performs detailed focus adjustment using the OCT moving image.

(S15: Acquire a tomographic image of the fundus)
In response to completion of the detailed focus adjustment in step 14 or a predetermined operation by the user, the main control unit 211 controls the OCT unit 100, the optical path length changing unit 41, the galvano scanner 42, etc. OCT measurement of the fundus oculi Ef is performed. This OCT measurement is executed in a preset scan mode. Thereby, a tomographic image for diagnosis is acquired.

(S16: The target position of the focusing lens of the photographing optical system is obtained)
In response to the end of the OCT measurement or a predetermined operation by the user, the target position acquisition unit 214 detects the position of the focusing lens 43 applied in the OCT measurement in step 15, that is, the focus adjustment in step 14. Based on the set position of the focusing lens 43, the target position of the focusing lens 31 of the photographing optical system is obtained.

(S17: Move the focusing lens of the photographing optical system to the target position)
The main control unit 211 controls the focusing drive unit 31A so as to move the focusing lens 31 to the target position acquired in step 16.

(S18: The fundus is photographed to obtain a photographed image)
The main controller 211 controls the illumination optical system 10 (such as the photographing light source 15) and the photographing optical system to acquire a photographed image of the fundus oculi Ef. The main control unit 211 causes the display unit 240A to display the acquired captured image. In addition, the main control unit 211 causes the storage unit 212 to store the acquired captured image. This is the end of this operation example.

[Action / Effect]
The operation and effect of the ophthalmologic observation apparatus of this embodiment will be described.

  Similarly to the first embodiment, the ophthalmic observation apparatus according to this embodiment includes a photographing optical system, a measurement optical system, an optical path synthesis unit, a first drive unit, a second drive unit, and a control unit. . Therefore, each of the photographing optical system and the measurement optical system has a focusing lens, and these focusing lenses can be individually controlled. Therefore, it is possible to arrange the first focusing lens at the optimum focus position for acquiring the front image and to arrange the second focusing lens at the optimum focus position for OCT measurement. Thereby, it is possible to perform both the acquisition of the front image of the eye E and the OCT measurement in a suitable focus state.

  In this embodiment, the control unit (control unit 210) acquires the target position of the focusing lens 31 of the imaging optical system based on the position of the focusing lens 43 of the measurement optical system when the OCT measurement is performed. A target position acquisition unit 214 (second target position acquisition unit) is included. Further, the control unit is configured to control the focusing drive unit 31 </ b> A so as to move the focusing lens 31 to the target position acquired by the target position acquisition unit 214.

  According to such an embodiment, since the focus adjustment on the imaging optical system side can be performed with reference to the result of the high-accuracy and high-accuracy focus adjustment using the OCT image, the eye E to be examined with a good focus state The front image of can be acquired. Further, there is a possibility that the focus of the photographing optical system is shifted due to eye movement or the like during the OCT measurement. In this case, according to this embodiment, since the focus adjustment of the photographing optical system can be performed from the focus state at the time of OCT measurement, photographing for acquiring a front image is performed in a suitable focus state. Is possible. Further, since the focus adjustment of the photographing optical system can be automatically performed after the OCT measurement, the user's hand is not bothered.

  The process of acquiring the target position of the focusing lens 31 of the photographing optical system can be performed based on the OCT moving image. That is, in this embodiment, the OCT moving image of the cross section can be acquired by repeatedly performing OCT measurement on substantially the same cross section of the eye E with the measurement optical system. Further, the target position acquisition unit 214 determines the alignment of the imaging optical system based on the position of the focusing lens 43 set based on a plurality of tomographic images (OCT moving image frames) acquired by this repetitive OCT measurement. The target position of the focal lens 31 can be acquired.

  As described above, when the OCT moving image is used, the image of the fundus oculi Ef can be held at a predetermined position in the frame as described above. Therefore, even when eye movement or pulsation occurs during OCT measurement, the target position of the focusing lens 31 of the photographing optical system can be acquired with high accuracy.

<Third Embodiment>
In this embodiment, a user interface for performing focus adjustment of an imaging optical system and a measurement optical system based on an OCT image will be described.

[Constitution]
The ophthalmic observation apparatus of this embodiment has the same overall configuration and optical system configuration as those of the first embodiment. The configuration of the control system is almost the same as that of the first embodiment. Hereinafter, the same components as those in the first embodiment will be described using the same reference numerals.

  A configuration example of the control system of the ophthalmic observation apparatus of this embodiment is shown in FIG. In this embodiment, a target position acquisition unit 215 is provided instead of the target position acquisition unit 213 of the first embodiment. Further, the correspondence information 212 a does not need to be stored in the storage unit 212, and the analysis unit 231 does not need to be provided in the image processing unit 230. Further, the image processing unit 230 is provided with a layer region specifying unit 232. Hereinafter, these differences will be mainly described.

  The main control unit 211 displays a tomographic image of the fundus oculi Ef acquired by OCT measurement by the measurement optical system on the display unit 240A. The user designates a desired position in the displayed tomogram using the operation unit 240B. This desired position is a position (focus target position) where the user wants to focus in the tomographic image.

  The focus target position may be the focus target position of the measurement optical system or the focus target position of the photographing optical system. Further, a user interface capable of designating both focus target positions may be provided, or a user interface capable of designating only one of them may be provided.

  The focus target positions of both optical systems may be the same or different from each other. When the former is applied, a user interface capable of individually specifying both focus target positions or a user interface capable of collectively specifying both focus target positions is provided. When the latter is applied, a user interface capable of individually specifying both focus target positions is provided. When the relationship between both focus target positions is determined in advance based on the eye refractive power, wavelength, etc., it is configured to automatically specify the other upon receiving the result of specifying one focus target position. Is possible. The specific configuration of the user interface exemplified here is arbitrary.

  The target position acquisition unit 215 uses the operation unit 240B to specify the target position (first target position) of the focusing lens 31 and / or the target position of the focusing lens 43 (first target position) based on the position specified for the tomographic image. 2nd target position) is acquired. The target position acquisition unit 215 is an example of a third target position acquisition unit. The processing executed by the target position acquisition unit 215 to acquire these target positions is arbitrary. Hereinafter, a configuration of the user interface and an example of processing executed by the target position acquisition unit 215 will be described.

[First processing example]
A first processing example will be described with reference to FIG. In this processing example, the focus position is designated by freezing (still image display) the OCT moving image.

(S21: OCT moving image is displayed)
The main control unit 211 controls the OCT unit 100, the optical path length changing unit 41, the galvano scanner 42, and the like to repeatedly perform OCT measurement on substantially the same cross section of the eye E (fundus Ef). The main control unit 211 causes the display unit 240A to display the OCT moving image in real time based on the plurality of tomographic images acquired by the repetitive OCT measurement.

(S22: Switch to still image display)
The main control unit 211 switches the tomographic image display mode from moving image display to still image display in response to a predetermined operation (an operation for instructing still image display) performed by the operation unit 240B.

  At this time, the still image and the moving image may be displayed side by side. For example, a display area (still image display area) for displaying a still image is provided on the display screen separately from the display area of the real-time OCT moving image. Then, in response to the operation for instructing the still image display, the OCT moving image frame (still image) corresponding to the timing at which the operation is performed is displayed as a still image while the OCT moving image is displayed as it is. It can be configured to be displayed in the area. When the operation is performed a plurality of times, the still image displayed in the still image display area may be updated every time the operation is performed. Alternatively, still images obtained at each operation may be displayed side by side. At this time, a plurality of still images may be displayed in the same size, a part of the plurality of still images may be displayed in a reduced size (thumbnail display or the like), or the display may be terminated.

(S23: Specify the position in the tomographic image)
The user operates the operation unit 240B to designate a desired position in the tomographic image displayed as a still image. This designated position is, for example, a position indicating a desired tissue of the fundus oculi Ef drawn on the tomographic image.

  The number of designated positions is arbitrary. For example, it is possible to specify a position indicating a part (fundus surface, etc.) to be observed in detail in a captured image and a position indicating a part (retinal pigment epithelium, choroid, etc.) to be observed in detail in a tomographic image. . In addition, when two or more positions are designated, information enabling each designated position to be determined may be input. For example, information indicating that the first designated position is a fundus photographing position and information indicating that the second designated position is an OCT measurement position can be input.

  When there is one designated position, the designated position is for a predetermined application (for OCT measurement or fundus imaging).

  Information indicating the designated position can be displayed together with the tomographic image. For example, it is possible to display an image indicating the designated position so as to overlap the tomographic image. In addition, when the above-described function of following the OCT moving image to the eye movement or pulsation is provided, the information indicating the designated position can be changed with time so as to follow the eye movement or the like. When the display mode of the tomographic image is switched to the moving image display, the display position of the image indicating the designated position is also changed over time.

(S24: Find the target position of the focusing lens)
The target position acquisition unit 215, based on the position specified in the tomographic image in step 23, the target position of the focusing lens 31 (first target position) and / or the target position of the focusing lens 43 (second target position). Ask for.

  The acquisition process of the first target position is performed based on, for example, the coordinates (z coordinate) of the first designated position in the depth direction (z direction) of the tomographic image frame. The second target position acquisition process is performed based on, for example, the coordinates (z coordinate) of the second designated position in the depth direction (z direction) of the tomographic image frame. Here, it is assumed that the z coordinate of the frame is associated with the position of the focusing lens 31 and / or the position of the focusing lens 43 in advance. It is also possible to correct the target position based on the eye refractive power or the like.

(S25: Move the focusing lens to the target position)
When the first target position is acquired in step 24, the main control unit 211 controls the focusing drive unit 31A to move the focusing lens 31 to the first target position. When the second target position is acquired in step 24, the main control unit 211 controls the focusing drive unit 43A to move the focusing lens 43 to the second target position.

(S26: OCT measurement of the fundus is performed to obtain a tomographic image)
The main control unit 211 controls the OCT unit 100, the optical path length changing unit 41, the galvano scanner 42, and the like to perform OCT measurement of the fundus oculi Ef. The image forming unit 220 forms a tomographic image of the fundus oculi Ef based on the detection signal from the CCD 115. The main controller 211 displays the formed tomographic image on the display 240A. The main control unit 211 stores the formed tomographic image in the storage unit 212.

(S27: The fundus is photographed to obtain a photographed image)
The main controller 211 controls the illumination optical system 10 (such as the imaging light source 15) and the imaging optical system 30 to acquire a captured image of the fundus oculi Ef. The main control unit 211 causes the display unit 240A to display the acquired captured image. In addition, the main control unit 211 causes the storage unit 212 to store the acquired captured image. This is the end of this operation example.

[Second processing example]
A second processing example will be described with reference to FIG. In this processing example, the focus position is designated by moving the position designation image displayed on the OCT moving image to a desired position.

(S31: Display OCT video)
The main control unit 211 controls the OCT unit 100, the optical path length changing unit 41, the galvano scanner 42, and the like to repeatedly perform OCT measurement on substantially the same cross section of the eye E (fundus Ef). The main control unit 211 causes the display unit 240A to display the OCT moving image in real time based on the plurality of tomographic images acquired by the repetitive OCT measurement.

(S32: A position designation image is displayed)
The main control unit 211 places a predetermined position designation image at a position on the OCT moving image corresponding to the focus position (that is, the position of the focusing lens 43) when the repetitive OCT measurement in step 31 is performed. Display.

  When the z coordinate in the OCT moving image (frame thereof) and the position of the focusing lens 43 are associated in advance, the main control unit 211 corresponds to the position of the focusing lens 43 during OCT measurement. The middle position (z coordinate) is obtained, and the position designation image is displayed so as to overlap this position. Further, the display position of the position designation image may be corrected based on the refractive power of the eye E or the like.

  The position specifying image is, for example, a linear image that passes through the position (z coordinate) and is orthogonal to the depth direction (z direction). The position designation image is a linear or arrow image displayed at a position outside the frame of the OCT moving image corresponding to the position (z coordinate). In general, the position designation image is an image superimposed on the OCT moving image or displayed in the vicinity of the OCT moving image, and is an image having a function of presenting a focus position in the OCT moving image.

  When the above-described function of following the OCT moving image to the eye movement or pulsation is provided, the display position of the position designation image can be changed with time so as to follow the eye movement or the like.

  The number of position designation images to be displayed is arbitrary. For example, a first position designating image for designating a site (fundus surface etc.) to be observed in detail in the captured image and a site for designating a site (retinal pigment epithelium, choroid, etc.) to be observed in detail in the tomogram It is possible to display two position designation images. When two or more position designation images are displayed, each position designation image may be displayed so as to be distinguishable. For example, the display mode (display color or the like) of the first position designation image may be configured to be different from the display mode of the second position designation image.

  When one position designation image is displayed, the position designation image is for a predetermined application (for OCT measurement or fundus imaging).

(S33: Move the position designation image to a desired position)
The user operates the operation unit 240B to move the position designation image to a desired position. This desired position is, for example, a position indicating a desired tissue of the fundus oculi Ef drawn on the tomographic image.

(S34: Find the target position of the focusing lens)
The target position acquisition unit 215 performs the target position (first target position) of the focusing lens 31 and / or the target position (first position) of the focusing lens 43 based on the position of the position designation image after being moved in Step 33. 2 target position).

  The acquisition process of the first target position is performed based on, for example, the coordinates (z coordinate) of the first position designation image in the depth direction (z direction) of the tomographic image frame. The second target position acquisition process is performed based on, for example, the coordinates (z coordinate) of the second position designation image in the depth direction (z direction) of the tomographic image frame. Here, it is assumed that the z coordinate of the frame is associated with the position of the focusing lens 31 and / or the position of the focusing lens 43 in advance. It is also possible to correct the target position based on the eye refractive power or the like.

(S35: Move the focusing lens to the target position)
When the first target position is acquired in step 34, the main control unit 211 controls the focusing drive unit 31A to move the focusing lens 31 to the first target position. When the second target position is acquired in step 34, the main control unit 211 controls the focusing drive unit 43A to move the focusing lens 43 to the second target position.

(S36: A tomogram is acquired by performing OCT measurement of the fundus)
The main control unit 211 controls the OCT unit 100, the optical path length changing unit 41, the galvano scanner 42, and the like to perform OCT measurement of the fundus oculi Ef. The image forming unit 220 forms a tomographic image of the fundus oculi Ef based on the detection signal from the CCD 115. The main controller 211 displays the formed tomographic image on the display 240A. The main control unit 211 stores the formed tomographic image in the storage unit 212.

(S37: The fundus is photographed to obtain a photographed image)
The main controller 211 controls the illumination optical system 10 (such as the imaging light source 15) and the imaging optical system 30 to acquire a captured image of the fundus oculi Ef. The main control unit 211 causes the display unit 240A to display the acquired captured image. In addition, the main control unit 211 causes the storage unit 212 to store the acquired captured image. This is the end of this operation example.

[Other processing examples]
In the first and second processing examples described above, the following processing can be performed. First, the layer region specifying unit 232 analyzes a tomographic image (still image constituting the OCT moving image) displayed on the display unit 240A, and specifies a layer region corresponding to a predetermined layer in the tomographic image. This layer region is an image region corresponding to at least one of predetermined layer tissues of the fundus oculi Ef having a layer structure. The layer structure of the fundus oculi Ef includes the inner boundary membrane, nerve fiber layer, ganglion cell layer, inner reticular layer inner granular layer, outer reticular layer, outer granular layer, outer boundary membrane, photoreceptor cell layer, retinal pigment epithelial layer , Choroid and sclera.

  The main control unit 211 displays an image (layer image) indicating the layer region specified by the layer region specifying unit 232 so as to overlap the tomographic image. When the above-described function of following the OCT moving image to the eye movement or pulsation is provided, the main control unit 211 can change the display position of the position designation image with time so as to follow the eye movement or the like. It is.

[Action / Effect]
The operation and effect of the ophthalmologic observation apparatus of this embodiment will be described.

  Similarly to the first embodiment, the ophthalmic observation apparatus according to this embodiment includes a photographing optical system, a measurement optical system, an optical path synthesis unit, a first drive unit, a second drive unit, and a control unit. . Therefore, each of the photographing optical system and the measurement optical system has a focusing lens, and these focusing lenses can be individually controlled. Therefore, it is possible to arrange the first focusing lens at the optimum focus position for acquiring the front image and to arrange the second focusing lens at the optimum focus position for OCT measurement. Thereby, it is possible to perform both the acquisition of the front image of the eye E and the OCT measurement in a suitable focus state.

  The ophthalmic observation apparatus according to this embodiment includes a display unit (display unit 240A) and an operation unit (operation unit 240B). The display unit displays a tomographic image acquired by OCT measurement by the measurement optical system. The operation unit is used for designating a position in the tomographic image displayed on the display unit. Furthermore, the control unit (control unit 210) of this embodiment includes a third target position acquisition unit (target position acquisition unit 215). The third target position acquisition unit acquires the target position of the first focusing lens (focusing lens 31) and / or the second focusing lens (focusing lens 43) based on the position specified by the operation unit. . Then, the control unit moves the first focusing lens and / or the second focusing lens to the target position acquired by the third target position acquisition unit, and the first driving unit (focusing driving unit 31A) and The second drive unit (focus drive unit 43A) is controlled.

  When the measurement optical system repeatedly performs OCT measurement on substantially the same cross section of the eye to be examined, the display unit can display a plurality of tomographic images acquired by the repeated OCT measurement as moving images. Furthermore, the control unit switches the moving image display to the still image display in response to a predetermined operation performed by the operation unit. The third target position acquisition unit can acquire the target positions of the first focusing lens and the second focusing lens based on the position designated by the operation unit with respect to the tomographic image displayed as a still image. it can.

  In addition, when the measurement optical system repeatedly performs OCT measurement on substantially the same cross section of the eye to be examined to display a moving image, the following configuration can be employed. The display unit displays a position designation image that is movable with respect to the moving image by a predetermined operation by the operation unit. The third target position acquisition unit can acquire the target position of the first focusing lens and the second focusing lens based on the position specified by the operation on the position specifying image.

  As the position designation image, the control unit can display an image indicating a position on the moving image corresponding to the position of the second focusing lens when repetitive OCT measurement is performed.

  According to such an embodiment, a desired focus position can be designated for the tomographic image, and the focus position in photographing of the eye to be examined or OCT measurement can be automatically adjusted to the designated position.

<Fourth Embodiment>
In order to optimize the focus position of OCT measurement in actual inspection, not only the difference between the wavelength of light for imaging (visible light etc.) and the wavelength of light for OCT measurement (near infrared light etc.), It is desirable to pay attention to individual differences in the optical characteristics of the eye to be examined. In this embodiment, focus adjustment for OCT measurement in consideration of optical characteristics of an eye to be examined will be described. This focus adjustment is performed in two stages, coarse adjustment and fine adjustment. Coarse adjustment is performed using a split index (focus index) or using a measured value of the refractive power of the eye to be examined. The fine adjustment is performed based on the interference sensitivity of the OCT measurement.

[Constitution]
The ophthalmic observation apparatus of this embodiment has the same overall configuration and optical system configuration as those of the first embodiment. The configuration of the control system is almost the same as that of the first embodiment. Hereinafter, the same components as those in the first embodiment will be described using the same reference numerals.

  A configuration example of the control system of the ophthalmic observation apparatus of this embodiment is shown in FIG. The control unit 210 is provided with a target position acquisition unit 216. Further, the image forming unit 220 is provided with an interference intensity acquisition unit 221.

  The interference intensity acquisition unit 221 acquires the intensity (interference intensity) of an interference signal obtained by a measurement optical system that performs OCT measurement. The interference signal is a detection signal output from the CCD image sensor 115 or a signal obtained by performing predetermined signal processing on the detection signal. Examples of this predetermined signal processing include arbitrary signal processing used in the spectral domain OCT or the swept source OCT. The interference intensity acquisition unit 221 acquires the interference intensity by detecting the amplitude of the interference signal, for example. The interference intensity acquisition unit 221 is an example of an “intensity acquisition unit”.

  In this embodiment, a plurality of interference signals are acquired while changing the position of the focusing lens 43 of the measurement optical system. The interference intensity acquisition unit 221 determines the intensity of each interference signal. In addition, the process which acquires a some interference signal is performed as follows, for example.

  The main control unit 211 controls the focusing drive unit 43 to move the focusing lens 43. The movement form may be continuous movement or intermittent movement (step movement). In the former case, the main control unit 211 controls the measurement optical system (such as the light source unit 101) and continuously performs OCT measurement a plurality of times while continuously moving the focusing lens 43. In the latter case, the main control unit 211 performs OCT measurement on the measurement optical system in a state where the focusing lens 43 is disposed at each position while the focusing lens 43 is sequentially disposed at the first to Nth positions. Let By performing such control, a plurality of interference signals corresponding to a plurality of positions of the focusing lens 43 are obtained.

  In the above control, the moving range of the focusing lens 43 can be set in advance. That is, a plurality of interference signals can be acquired by performing the OCT measurement a plurality of times while moving the focusing lens 43 within a predetermined range. The moving range of the focusing lens 43 includes a position determined in advance by rough adjustment (focus adjustment based on the split index) described later. As an example, the moving range of the focusing lens 43 is set so that the position (reference position) determined by coarse adjustment is the center. The moving range of the focusing lens 43 can be defined by a change in refractive power corresponding to the movement of the focusing lens 43 along the optical axis of the measurement optical system. As a specific example, the moving range of the focusing lens 43 is set to a range of ± 3 diopters centered on the reference position.

  The target position acquisition unit 216 acquires the target position of the focusing lens 43 based on the plurality of interference intensities acquired by the interference intensity acquisition unit 221. The target position acquisition unit 216 is an example of a “fourth target position acquisition unit”.

  An example of processing executed by the target position acquisition unit 216 will be described. First, the target position acquisition unit 216 specifies the maximum intensity among the plurality of interference intensities acquired by the interference intensity acquisition unit 221. This process is performed by comparing the interference intensity values. Furthermore, the target position acquisition unit 216 sets the position of the focusing lens 43 corresponding to the specified maximum intensity as the target position. In this process, for example, the position when the interference signal having the maximum intensity is obtained from the positions of the plurality of focusing lenses 43 applied in the above-described plurality of OCT measurements, and this is set as the target position. Is done.

  The processing executed by the target position acquisition unit 216 is not limited to this. For example, the target position acquisition unit 216 acquires a change state of the interference intensity accompanying the movement of the focusing lens 43 based on the acquired plurality of interference intensity. This process includes, for example, a process of obtaining a curve (continuous value) that smoothly connects a plurality of interference intensity values (discrete values). For example, this curve is defined in a coordinate system in which the position of the focusing lens 43 is on the horizontal axis and the interference intensity is on the vertical axis. Furthermore, the target position acquisition unit 216 obtains a peak of the interference intensity from the acquired change state of the interference intensity. Then, the target position acquisition unit 216 obtains the position of the focusing lens 43 corresponding to the obtained peak. This position is either one of the plurality of positions of the focusing lens 43 applied in the plurality of OCT measurements, or none of them.

[Operation]
The operation of the ophthalmologic observation apparatus according to this embodiment will be described. FIG. 12 illustrates an example of the operation of the ophthalmologic observation apparatus.

(S41: Acquisition of observation image is started)
As in the first embodiment, acquisition of an observation image is started, and fixation of the eye E is performed.

(S42: Perform alignment)
Similar to the first embodiment, the alignment index and the split index are projected onto the eye E to be examined. Then, alignment using the alignment index is executed.

(S43: Perform coarse focus adjustment)
Focus adjustment (rough adjustment) using a split index is performed. The rough adjustment may be performed manually or automatically (autofocus). The focus adjustment using the split index has been described above.

  The focus adjustment at this stage is performed for both the photographing optical system 30 and the measurement optical system. For example, the position of the focusing lens 31 of the photographing optical system 30 is determined using a split index as in a general fundus camera, and the focusing lens 43 is moved to a position corresponding to this position. Note that the relationship between the position of the focusing lens 31 and the position of the focusing lens 43 is determined in advance, and information indicating this relationship is stored in the storage unit 212.

(S44: Acquire a plurality of interference signals with different in-focus states)
The main control unit 211 acquires a plurality of interference signals while changing the position of the focusing lens 43 of the measurement optical system. This process is executed as described above.

(S45: Obtain interference intensity)
The interference intensity acquisition unit 221 determines the interference intensity of each of the plurality of interference signals acquired in step 44.

(S46: Find the target position of the focusing lens)
The target position acquisition unit 216 calculates the target position of the focusing lens 43 based on the plurality of interference intensities acquired in step 45.

(S47: Move the focusing lens to the target position)
The main control unit 211 controls the focusing drive unit 43 </ b> A to move the focusing lens 43 to the target position obtained in step 46.

(S48: A tomogram is acquired by performing OCT measurement of the fundus)
The main control unit 211 controls the OCT unit 100, the optical path length changing unit 41, the galvano scanner 42, and the like to perform OCT measurement of the fundus oculi Ef. The image forming unit 220 forms a tomographic image of the fundus oculi Ef based on the detection signal from the CCD 115. The main controller 211 displays the formed tomographic image on the display 240A. The main control unit 211 stores the formed tomographic image in the storage unit 212. This OCT measurement is performed in a focus state finely adjusted based on the interference intensity. Therefore, OCT measurement with high sensitivity is possible.

(S49: Capturing the fundus and acquiring the captured image)
The main controller 211 controls the illumination optical system 10 (such as the imaging light source 15) and the imaging optical system 30 to acquire a captured image of the fundus oculi Ef. The main control unit 211 causes the display unit 240A to display the acquired captured image. In addition, the main control unit 211 causes the storage unit 212 to store the acquired captured image. Note that this fundus imaging is performed in a suitable focus state adjusted in step 43 based on the split index. This is the end of this operation example.

[Action / Effect]
The operation and effect of the ophthalmologic observation apparatus of this embodiment will be described.

  Similarly to the first embodiment, the ophthalmic observation apparatus according to this embodiment includes a photographing optical system, a measurement optical system, an optical path synthesis unit, a first drive unit, a second drive unit, and a control unit. . Therefore, each of the photographing optical system and the measurement optical system has a focusing lens, and these focusing lenses can be individually controlled. Therefore, it is possible to arrange the first focusing lens at the optimum focus position for acquiring the front image and to arrange the second focusing lens at the optimum focus position for OCT measurement. Thereby, it is possible to perform both the acquisition of the front image of the eye E and the OCT measurement in a suitable focus state.

  In this embodiment, the measurement optical system performs optical coherence tomography measurement for acquiring a tomographic image of the fundus oculi Ef. Further, the ophthalmic observation apparatus of this embodiment includes a focus optical system 60 (projection optical system) and an interference intensity acquisition unit 221 (intensity acquisition unit). The projection optical system projects a split index (focus index) indicating the focus state of the photographing optical system 30 with respect to the fundus oculi Ef onto the fundus oculi Ef. The interference intensity acquisition unit 221 acquires the intensity of the interference signal obtained by the measurement optical system. Further, after focus adjustment (coarse adjustment) of the imaging optical system 30 and the measurement optical system based on the split index is performed, the main control unit 211 performs focus drive based on the interference intensity acquired by the interference intensity acquisition unit 221. The focus state of the measurement optical system is finely adjusted by controlling the unit 43A.

  In this embodiment, the control unit 210 can execute the following processing. First, the main control unit 211 controls the focusing optical unit 43A to control the measurement optical system while moving the focusing lens 43, thereby generating a plurality of interference signals corresponding to a plurality of positions of the focusing lens 43. Get it. Next, the target position acquisition unit 216 acquires the target position of the focusing lens 43 based on the plurality of interference intensities acquired by the interference intensity acquisition unit 221. Further, the main control unit 211 controls the focusing drive unit 43A so as to move the focusing lens 43 to the acquired target position.

  The target position acquisition unit 216 specifies the maximum intensity among the plurality of interference intensities acquired by the interference intensity acquisition unit 221 and adopts the position of the focusing lens 43 corresponding to the specified maximum intensity as the target position. Can do.

  The main control unit 211 can improve the efficiency of fine adjustment by moving the focusing lens 43 within a predetermined range in acquiring a plurality of interference signals. This predetermined range may include the position of the focusing lens 43 determined by rough adjustment. In particular, the center of the predetermined range may be the position of the focusing lens 43 determined by the coarse adjustment.

  Coarse adjustment is performed manually or automatically. When performing automatically, the ophthalmic observation apparatus of this embodiment is configured as follows. First, the imaging optical system 30 includes an infrared imaging optical system that performs imaging for acquiring a front image of the fundus oculi Ef using infrared light. As the infrared imaging optical system, for example, the optical system described in the first embodiment for illuminating the eye E with observation illumination light and detecting the reflected light is applied. The main control unit 211 moves the focusing lens 31 and the focus optical system 60 based on the front image obtained by photographing the fundus oculi Ef on which the split index is projected with the infrared photographing optical system. The system 30 is focused, and the measurement optical system is focused (the focusing lens 43 is moved) based on the focusing result.

  According to such an embodiment, since the focus state of the measurement optical system can be adjusted based on the interference intensity, it is possible to perform highly sensitive OCT measurement. For example, even when the split index is kicked by the pupil and the coarse adjustment cannot be suitably performed, the OCT measurement can be performed in a favorable focus state. Further, since the coarse adjustment is performed before the fine adjustment, the fine adjustment can be smoothly started.

[Modification]
A modification of this embodiment will be described.

  Instead of using the split index, it is possible to perform rough adjustment using a measured value of the refractive power of the eye E acquired in advance. The configuration of the ophthalmic observation apparatus according to this modification may be the same as that of the fourth embodiment unless otherwise specified (see FIG. 11).

  The storage unit 212 stores a measurement value of the refractive power of the eye E to be acquired in advance. This measured value may be acquired by another ophthalmologic apparatus (such as an autorefractometer) or may be acquired by this ophthalmologic observation apparatus. In the former case, the main control unit 211 causes the storage unit 212 to store the measurement value input to the ophthalmic observation apparatus. In the latter case, the ophthalmic observation apparatus is provided with a refractive power acquisition unit that acquires the refractive power of the eye to be examined. The refractive power acquisition unit has, for example, the configuration described in the first embodiment. The main control unit 211 causes the storage unit 212 to store the refractive power acquired by the refractive power acquisition unit.

  The interference intensity acquisition unit 221 acquires the intensity of the interference signal obtained by the measurement optical system, as in the above embodiment. The main control unit 211 causes focus adjustment of the imaging optical system 30 and the measurement optical system based on the measurement values stored in the storage unit 212 as coarse adjustment of the focus state. The focus adjustment based on the eye refractive power is executed, for example, in the same manner as in the first embodiment. Further, the main control unit 211 performs fine adjustment of the focus state of the measurement optical system by controlling the focusing drive unit 43A based on the interference intensity acquired by the interference intensity acquisition unit 221.

  According to this modification, since the focus state of the measurement optical system can be adjusted based on the interference intensity, highly sensitive OCT measurement can be performed. Further, since the coarse adjustment is performed before the fine adjustment, the fine adjustment can be smoothly started. In addition, even when the ophthalmic observation apparatus does not have a function of projecting a focus index such as a split index, or when there is a problem with the function, rough adjustment of the focus state can be performed.

<Modification>
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. Moreover, it is possible to arbitrarily combine various configurations described in the above embodiments.

  In the above embodiment, the optical path length difference between the optical path of the signal light LS and the optical path of the reference light LR is changed by changing the position of the optical path length changing unit 41, but this optical path length difference is changed. The method is not limited to this. For example, it is possible to change the optical path length difference by disposing a reflection mirror (reference mirror) in the optical path of the reference light and moving the reference mirror in the traveling direction of the reference light to change the optical path length of the reference light. Is possible. Further, the optical path length difference may be changed by moving the fundus camera unit 2 or the OCT unit 100 with respect to the eye E to change the optical path length of the signal light LS. In particular, when the measured object is not a living body part, the optical path length difference can be changed by moving the measured object in the depth direction (z direction).

  A computer program for realizing the above embodiment can be stored in any recording medium readable by a computer. Examples of the recording medium include a semiconductor memory, an optical disk, a magneto-optical disk (CD-ROM / DVD-RAM / DVD-ROM / MO, etc.), a magnetic storage medium (hard disk / floppy (registered trademark) disk / ZIP, etc.), and the like. Can be used.

  It is also possible to transmit / receive this program through a network such as the Internet or a LAN.

DESCRIPTION OF SYMBOLS 1 Ophthalmologic observation apparatus 2 Fundus camera unit 10 Illumination optical system 30 Shooting optical system 31 Focus lens 31A Focus drive part 41 Optical path length change part 42 Galvano scanner 43 Focus lens 43A Focus drive part 60 Focus optical system 60A Optical system drive Unit 100 OCT unit 200 arithmetic control unit 210 control unit 211 main control unit 212 storage unit 212a correspondence information 213, 214, 215, 216 target position acquisition unit 220 image forming unit 221 interference intensity acquisition unit 230 image processing unit 231 analysis unit 232 layer Area specifying unit 240A Display unit 240B Operation unit E Eye to be examined Ef Fundus

Claims (9)

An imaging optical system that includes a first focusing lens and that performs imaging for acquiring a front image of the eye to be examined;
A measurement optical system that includes a second focusing lens and performs optical coherence tomography measurement for obtaining a tomographic image of the eye to be examined;
An optical path synthesis unit that synthesizes the optical path of the imaging optical system and the optical path of the measurement optical system at a position closer to the subject's eye than the first focusing lens and the second focusing lens;
A first drive unit for moving the first focusing lens along the optical axis of the photographing optical system;
A second drive unit for moving the second focusing lens along the optical axis of the measurement optical system;
A control unit for controlling each of the first drive unit and the second drive unit,
The measurement optical system performs optical coherence tomography measurement for obtaining a tomographic image of the fundus of the eye to be examined,
A projection optical system for projecting an in-focus index indicating the in-focus state of the photographing optical system with respect to the fundus;
An intensity acquisition unit that acquires the intensity of the interference signal obtained by the measurement optical system;
After the imaging optical system and the measurement optical system are focused based on the focus index, the control unit controls the second drive unit based on the intensity acquired by the intensity acquisition unit. Ophthalmic observation device characterized by. The controller is
By controlling the measurement optical system while moving the second focusing lens by controlling the second drive unit, to obtain a plurality of interference signals corresponding to a plurality of positions of the second focusing lens,
A fourth target position acquisition unit that acquires a target position of the second focusing lens based on the intensity of the plurality of interference signals acquired by the intensity acquisition unit;
The ophthalmic observation apparatus according to claim 1, wherein the second drive unit is controlled to move the second focusing lens to the acquired target position.   The fourth target position acquisition unit specifies a maximum intensity among the intensities of the plurality of interference signals, and sets a position of the focusing lens corresponding to the specified maximum intensity as a target position. Item 3. An ophthalmic observation apparatus according to Item 2.   4. The ophthalmic observation apparatus according to claim 2, wherein the control unit moves the second focusing lens within a predetermined range in acquiring the plurality of interference signals. 5.   The ophthalmic observation apparatus according to claim 4, wherein the predetermined range includes a position of the second focusing lens that is determined in advance based on the focusing index.   The ophthalmic observation apparatus according to claim 5, wherein the center of the predetermined range is the position determined in advance. The imaging optical system includes an infrared imaging optical system that performs imaging for acquiring a front image of the fundus of the eye to be examined using infrared light,
The control unit moves the first focusing lens and the projection optical system based on a front image obtained by photographing the fundus in a state where a focus index is projected with the infrared imaging optical system. The ophthalmic observation apparatus according to claim 1, wherein the imaging optical system is focused, and the measurement optical system is focused based on the focusing result. An imaging optical system that includes a first focusing lens and that performs imaging for acquiring a front image of the eye to be examined;
A measurement optical system that includes a second focusing lens and performs optical coherence tomography measurement for obtaining a tomographic image of the eye to be examined;
An optical path synthesis unit that synthesizes the optical path of the imaging optical system and the optical path of the measurement optical system at a position closer to the subject's eye than the first focusing lens and the second focusing lens;
A first drive unit for moving the first focusing lens along the optical axis of the photographing optical system;
A second drive unit for moving the second focusing lens along the optical axis of the measurement optical system;
A control unit for controlling each of the first drive unit and the second drive unit,
The measurement optical system performs optical coherence tomography measurement for obtaining a tomographic image of the fundus of the eye to be examined,
A storage unit for storing a measured value of the refractive power of the eye to be obtained in advance;
An intensity acquisition unit that acquires the intensity of the interference signal obtained by the measurement optical system;
After the focusing of the photographing optical system and the measurement optical system based on the measurement value, the control unit controls the second driving unit based on the intensity acquired by the intensity acquisition unit. A characteristic ophthalmic observation device. It has a refractive power acquisition unit that acquires the refractive power of the eye to be examined,
The ophthalmic observation apparatus according to claim 8, wherein the control unit stores the acquired refractive power in the storage unit as the measurement value.

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