JP6899661B2 - Ophthalmic equipment - Google Patents

Description

The present invention relates to an ophthalmic apparatus.

The ophthalmologic apparatus includes an ophthalmologic imaging apparatus for obtaining an image of the eye to be inspected and an ophthalmologic measuring apparatus for measuring the characteristics of the eye to be inspected.

Examples of ophthalmologic imaging devices include an optical coherence tomography that obtains a tomographic image using optical coherence tomography (OCT), a fundus camera that photographs the fundus, and a fundus image by laser scanning using a confocal optical system. There are scanning laser ophthalmoscopes (SLO) and the like.

In addition, as an example of an ophthalmic measuring device, an ophthalmic refraction tester (refractometer, keratometer) for measuring the refraction characteristics of the eye to be inspected, a tonometer, a specular microscope for obtaining corneal characteristics (corneal thickness, cell distribution, etc.), and Hartmann. -There is a wave front analyzer that obtains aberration information of the eye to be inspected using a shack sensor.

In an ophthalmic examination, the alignment between the device optical system and the eye to be inspected is extremely important from the viewpoint of the accuracy and accuracy of the examination. This alignment is called alignment. Alignment includes an operation of aligning the optical axis of the device optical system with the axis of the eye to be inspected (XY alignment) and an operation of adjusting the distance between the eye to be inspected and the device optical system to a predetermined distance (Z alignment). included.

There are various methods for alignment. As a typical method, a method of projecting light onto the cornea, detecting the reflected image (Purkinje image), and performing alignment is known (see, for example, Patent Document 1).

In addition, as a method realized in recent years, two or more captured images obtained by photographing the anterior segment from different directions are analyzed to identify the three-dimensional position of the eye to be inspected, and XY alignment is performed based on the three-dimensional position. There is a method of performing both and Z alignment (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 10-024019 Japanese Unexamined Patent Publication No. 2013-248376

In such a conventional alignment method, it is necessary to provide an optical system for alignment in the ophthalmic apparatus. However, while high-precision alignment is required for ophthalmic devices, simplification of the configuration is required. In particular, portable ophthalmic devices are required to have a smaller optical system.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a new method for alignment of an ophthalmic apparatus.

A first aspect of the ophthalmic apparatus according to an embodiment is an optical system for collecting data by scanning an area including at least a part of the front surface of the subject's face using optical coherence stromography, and the optics. Based on the drive unit that relatively moves the eye to be inspected and the optical system in the optical axis direction of the system and the data collected by the optical system, the first position corresponding to at least a part of the region is specified. The analysis unit includes a control unit for relatively moving the eye to be inspected and the optical system by controlling the drive unit based on the first position specified by the analysis unit.
In the second aspect of the ophthalmic apparatus according to the embodiment, in the first aspect, the optical system divides the light from the objective lens and the light source into a reference light and a measurement light, and the measurement light is passed through the objective lens. The analysis unit is detected by the interference optical system, which includes an interference optical system that irradiates the eye to be inspected with the light and detects the interference light between the return light of the measurement light from the eye to be inspected and the reference light. The first position is specified based on the detection result of the interference light, and the control unit determines the position of the objective lens, the first position, the optical path length of the reference light, and the optical path length of the measurement light. The eye to be inspected and the optical system are relatively moved based on the second position where is matched.
In the third aspect of the ophthalmic apparatus according to the embodiment, in the second aspect, the control unit has the first distance between the position of the objective lens and the second position, and the first in the detection result of the interference light. The eye to be inspected and the optical system are relatively moved based on the position corresponding to the two positions and the second distance between the first position.
In the fourth aspect of the ophthalmic apparatus according to the embodiment, in the third aspect, the control unit controls the eye to be inspected and the optical system so that the sum of the first distance and the second distance becomes a predetermined working distance. And move relative to each other.
In the fifth aspect of the ophthalmic apparatus according to the embodiment, in the third or fourth aspect, the interference optical system changes the optical path length so as to relatively change the optical path length of the reference light and the optical path length of the measurement light. The unit includes a distance specifying unit that specifies the first distance based on the optical path length difference between the optical path of the reference light and the optical path of the measured light changed by the optical path length changing unit.
In the sixth aspect of the ophthalmic apparatus according to the embodiment, in the fifth aspect, the optical path length changing portion is arranged in the optical path of the reference light or the optical path of the measurement light, and a corner cube that can move along the optical path is provided. Including.
The seventh aspect of the ophthalmic apparatus according to the embodiment includes, in the fifth or sixth aspect, a storage unit that stores in advance the corresponding information in which the information corresponding to the optical path length difference and the first distance are associated with each other. The distance specifying unit specifies the first distance based on the corresponding information stored in the storage unit.
In the eighth aspect of the ophthalmic apparatus according to the embodiment, in any one of the first to seventh aspects, an imaging unit that captures at least a part of the region is included, and the driving unit is in the optical axis direction of the optical system. The eye to be inspected and the optical system are relatively moved in a direction intersecting with, and the control unit is in a direction intersecting the optical axis direction of the optical system based on a captured image obtained by the photographing unit. After the eye to be inspected and the optical system are relatively moved, the eye to be inspected and the optical system are relatively moved in the optical axis direction based on the first position.
In the ninth aspect of the ophthalmic apparatus according to the embodiment, in any one of the first to eighth aspects, the support portion for supporting the face is included, and the drive portion relative to the support portion and the optical system. Move to.
In a tenth aspect of the ophthalmic apparatus according to the embodiment, in any of the first to ninth aspects, the optical system scans an area including the cornea, eyelids, nose, or cheeks.
It is possible to arbitrarily combine the configurations according to the plurality of claims described above.

It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is a schematic block diagram which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is a flowchart which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation example of the ophthalmic apparatus which concerns on embodiment. It is a flowchart which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is a flowchart which shows the operation example of the ophthalmic apparatus which concerns on embodiment.

An example of an embodiment of the ophthalmic apparatus according to the present invention will be described in detail with reference to the drawings. It should be noted that the description contents of the documents cited in this specification and arbitrary known techniques can be incorporated into the following embodiments.

The ophthalmic apparatus according to the embodiment has a function of an optical coherence tomography using OCT and is used for an optical examination of an eye to be inspected. Such an ophthalmic apparatus includes an ophthalmologic imaging apparatus and an ophthalmologic measuring apparatus having a function of an optical coherence tomography. In addition to the optical coherence tomography, the ophthalmologic imaging apparatus includes a fundus camera, a scanning laser ophthalmoscope, and a slit lamp. Further, as the ophthalmic measuring device, there are an ophthalmoflex test device, a tonometer, a specular microscope, a wavefront analyzer and the like. In the following embodiment, an ophthalmic apparatus having a function of an optical coherence tomography and a function of a fundus camera will be described as an example. However, this ophthalmic device is equipped with an ophthalmic device having only the function of an optical coherence tomography, and an optional function other than the function of an optical coherence tomometer and a fundus camera (any function of an ophthalmic imaging device or an ophthalmologic measuring device). The invention can be applied.

In this specification, the information (signal) acquired by OCT may be collectively referred to as OCT information (OCT signal), and the image acquired by OCT may be collectively referred to as an OCT image. Further, the measurement operation for forming an OCT image may be referred to as OCT measurement. Further, the optical system housed in the ophthalmic apparatus may be referred to as an apparatus optical system. In addition, the description content of the document described in this specification can be appropriately incorporated as the content of the following embodiment.

Further, in the following embodiment, an optical coherence tomography using a so-called Swept Source type OCT equipped with a wavelength sweep type light source and a balanced photodiode will be described. However, it is also possible to apply the present invention to optical coherence tomography using methods other than swept sources, such as spectral domain type and infuss type OCT. The spectral domain OCT divides the light from the low coherence light source into the measurement light and the reference light, and causes the return light of the measurement light from the test object to interfere with the reference light to generate interference light, and this interference occurs. This is a method in which the spectral distribution of light is detected by a spectroscope and the detected spectral distribution is subjected to Fourier transform or the like to form an image. Further, in-face OCT is to irradiate an object to be measured with light having a predetermined beam diameter and analyze the component of interference light obtained by superimposing the reflected light and the reference light. It is a method of forming an image of an object to be measured in a cross section orthogonal to the traveling direction of light, and is also called a full-field type.

In the following, the optical axis direction of the device optical system is the z direction (front-back direction), the horizontal direction orthogonal to the optical axis of the device optical system is the x direction (left-right direction), and the vertical direction orthogonal to the optical axis of the device optical system. Is the y direction (vertical direction).

[Constitution]
The ophthalmic apparatus 1 according to the embodiment includes an optical system (device optical system) for inspecting the eye to be inspected. As shown in FIGS. 1A and 1B, the ophthalmologic apparatus 1 accommodates a base 410, a housing 420 provided on the base 410, and a lens that can move three-dimensionally (in the xyz direction) with respect to the base 410. Includes part 430 and. The base 410 houses a drive system such as a drive unit of an optical system, which will be described later, and an arithmetic control circuit. The above optical system is housed in the housing 420. The lens accommodating portion 430 is provided so as to project from the front surface of the housing 420, and accommodates the objective lens 22 described later. The lens accommodating portion 430 shown in FIGS. 1A and 2A may be provided so as not to protrude from the front surface of the housing 420. At least one of the housing 420 and the lens accommodating portion 430 may be configured to be movable with respect to the base 410.

The ophthalmic apparatus 1 is fixed to the base 410 and is provided with a chin rest and a forehead pad for supporting the face of the subject. The chin rest and forehead rest correspond to the support portion 440 shown in FIGS. 1A and 1B.

As shown in FIG. 2, the ophthalmic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The fundus camera unit 2 has an optical system substantially similar to that of 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, control processes, and the like.

[Fundus camera unit]
The fundus camera unit 2 shown in FIG. 2 is provided with an optical system for acquiring a two-dimensional image (fundus image) showing the surface morphology of the fundus Ef of the eye E to be inspected. The fundus image includes an observation image, a photographed image, and the like. The observation image is, for example, a monochrome moving image formed at a predetermined frame rate using near-infrared light. When the optical system is in focus on the anterior segment of the eye E to be inspected, the fundus camera unit 2 can acquire an observation image of the anterior segment. 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 capable of acquiring images other than these, such as a fluorescein fluorescence image, an indocyanine green fluorescence image, and a spontaneous fluorescence image.

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 Ef with illumination light. The photographing optical system 30 guides the fundus reflected light of this illumination light to an imaging device (CCD image sensor (sometimes simply referred to as CCD) 35, 38). Further, the photographing optical system 30 guides the measurement light from the OCT unit 100 to the eye E (fundus Ef or the anterior eye portion), and guides the measurement light passing through the eye E to the OCT unit 100.

The observation light source 11 of the illumination optical system 10 is composed of, for example, a halogen lamp. The light output from the observation light source 11 (observation illumination light) is reflected by the reflection mirror 12 having a curved reflecting surface, passes through the condenser lens 13, passes through the visible cut filter 14, and becomes near-infrared light. Become. Further, the observation illumination light is once focused in the vicinity of the photographing light source 15, reflected by the mirror 16, and passes through the relay lenses 17, 18, the diaphragm 19, and the relay lens 20. Then, the observation illumination light is reflected at the peripheral portion of the perforated mirror 21 (the region around the perforated portion), passes through the dichroic mirror 46, is refracted by the objective lens 22, and illuminates the fundus Ef. It is also possible to use an LED (Light Emitting Diode) as an observation light source.

The fundus reflected 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 focused for photographing. It is reflected by the mirror 32 via the lens 31. Further, the reflected light from the fundus of the eye passes through the half mirror 39A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the CCD image sensor 35 by the condenser lens 34. The CCD image sensor 35 detects the fundus reflected light at a predetermined frame rate, for example. An image (observation image) based on the fundus reflected light detected by the CCD image sensor 35 is displayed on the display device 3. When the photographing optical system 30 is focused on the anterior segment of the eye, an observation image of the anterior segment of the eye to be inspected E is displayed.

The photographing light source 15 is composed of, for example, a xenon lamp. The light output from the photographing light source 15 (photographing illumination light) is applied to the fundus Ef through the same path as the observation illumination light. The fundus reflected light of the photographing 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 condensing lens 37 of the CCD image sensor 38. An image is formed on the light receiving surface. An image (captured image) based on the fundus reflected light detected by the CCD image sensor 38 is displayed on the display device 3. The display device 3 for displaying the observed image and the display device 3 for displaying the captured image may be the same or different. Further, when the eye E to be inspected is illuminated with infrared light and the same imaging is performed, an infrared captured image is displayed. It is also possible to use an LED as a photographing light source.

The LCD (Liquid Crystal Display) 39 displays a fixation target and an index for measuring visual acuity. The fixation target is an index for fixing the eye E to be inspected, and is used at the time of fundus photography, OCT measurement, and the like.

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 photographing focusing lens 31 and the dichroic mirror 55, and passes through the hole portion of the perforated mirror 21. The light that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef.

By changing the display position of the fixation target on the screen of the LCD 39, the fixation position of the eye E to be inspected can be changed. The fixation position of the eye E to be inspected includes, for example, a position for acquiring an image similar to that of a conventional fundus camera. Such images include an image centered on the macula of the fundus Ef, an image centered on the optic disc, and an image centered on the center of the fundus 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 a focus optical system 60 as in the conventional fundus camera. The alignment optical system 50 generates an index (alignment index) for aligning the device optical system with respect to the eye E to be inspected (alignment). The focus optical system 60 generates an index (split index) for focusing on the fundus 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 diaphragms 52 and 53 and the relay lens 54, and passes through the hole portion of the perforated mirror 21. The light that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46 and is projected onto the cornea of the eye E to be inspected by the objective lens 22.

The corneal reflex light of the alignment light passes through the objective lens 22, the dichroic mirror 46, and the above-mentioned hole, and a part of the light passes through the dichroic mirror 55, passes through the photographing focusing lens 31, is reflected by the mirror 32, and is half. It passes through the mirror 39A. The light transmitted through the half mirror 39A is reflected by the dichroic mirror 33 and projected onto the light receiving surface of the CCD image sensor 35 by the condenser lens 34. The received image (alignment index) by the CCD image sensor 35 is displayed on the display device 3 together with the observed image. The user performs the alignment by performing the same operation as the conventional fundus camera. Further, the arithmetic control unit 200 may analyze the position of the alignment index and move the optical system to perform alignment (auto alignment function). In this embodiment, since auto-alignment can be performed using OCT information as described later, it is not essential that auto-alignment using an alignment index is possible. However, it is possible to configure the auto-alignment using the alignment index so that the auto-alignment using the OCT information can be performed when the auto-alignment using the OCT information is not successful. Further, the auto alignment using the OCT information and the auto alignment using the alignment index may be configured to be selectively used.

When adjusting the focus, 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 luminous fluxes by the split index plate 63, and passes through the two-hole diaphragm 64. The light that has passed through the two-hole diaphragm 64 is reflected by the mirror 65, and is once imaged on the reflecting surface of the reflecting rod 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 Ef.

The fundus reflected light of the focus light is detected by the CCD image sensor 35 through the same path as the corneal reflected light of the alignment light. The received image (split index) by the CCD image sensor 35 is displayed on the display device 3 together with the observed image. The arithmetic control unit 200 analyzes the position of the split index and moves the photographing focusing lens 31 and the focus optical system 60 to perform focusing (autofocus function), as in the conventional case. In addition, focusing may be performed manually while visually recognizing the split index.

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

The optical path length changing unit 41 is movable in the direction of the arrow shown in FIG. 1, and changes the optical path length of the optical path for OCT measurement (optical path of measurement light). This change in the optical path length is used for correcting the optical path length according to the axial length of the eye E to be inspected, adjusting the interference state, moving the portion depicted in the OCT image, and the like. The optical path length changing unit 41 includes, for example, a corner cube and a moving mechanism (moving mechanism 41A described later) for moving the corner cube.

The optical scanner 42 changes the traveling direction of the light (measurement light LS) passing through the optical path for OCT measurement. Thereby, the fundus Ef or the anterior segment of the eye can be scanned with the measurement light LS. The optical scanner 42 includes, for example, a galvano mirror that scans the measurement light LS in the x direction, a galvano mirror that scans the measurement light LS in the y direction, and a mechanism that independently drives them. Thereby, the measurement light LS can be scanned in any 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 a region including at least a part of the front surface of the subject's face. The region may be a peripheral region of the eye E to be inspected (for example, the cornea). The peripheral area may be an area including the subject's eyelids, nose, or cheeks. This optical system has a configuration similar to that of a conventional swept source type OCT apparatus. That is, this optical system divides the light from the wavelength sweep type (wavelength scanning type) light source into the measurement light and the reference light, and separates the return light of the measurement light from the eye E to be examined and the reference light via the reference optical path. It is an interference optical system that causes interference to generate interference light and detects this interference light. The detection result (detection signal) of the interference light by the interference optical system is an interference signal showing the spectrum of the interference light, and is sent to the arithmetic control unit 200.

In the case of a spectral domain type OCT device, a light source that outputs a low coherence light source is provided instead of the wavelength sweep light source, and an optical member that spectrally decomposes the interference light is provided. In general, known techniques according to the type of OCT can be arbitrarily applied to the configuration of the OCT unit 100.

The light source unit 101 includes a wavelength sweep type (wavelength scanning type) light source capable of sweeping (scanning) the wavelength of the emitted light, similarly to a general swept source type OCT device. The wavelength sweep type light source is configured to include a laser light source including a resonator. The light source unit 101 changes the output wavelength with time in a near-infrared wavelength band that is invisible to the human eye.

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

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

The reference light LR is guided by the optical fiber 110 to the collimator 111 to become a parallel luminous flux. The reference light LR that has become a parallel luminous flux is guided to the corner cube 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 acts as a delay means for matching the optical path length (optical distance) of the reference light LR with the optical path length of the measurement light LS. The dispersion compensating member 113 acts as a dispersion compensating means for matching the dispersion characteristics between the reference light LR and the measurement light LS.

The corner cube 114 turns back the traveling direction of the reference light LR, which has become a parallel luminous flux by the collimator 111, in the opposite direction. The optical path of the reference light LR incident on the corner cube 114 and the optical path of the reference light LR emitted from the corner cube 114 are parallel. Further, the corner cube 114 is movable in the direction along the incident optical path and the outgoing optical path of the reference light LR. This movement changes the length of the optical path of the reference light LR.

In the configurations shown in FIGS. 2 and 3, the optical path length changing unit 41 for changing the length of the optical path (measurement optical path, measurement arm) of the measurement light LS and the optical path of the reference light LR (reference optical path, reference). Both corner cubes 114 for changing the length of the arm) are provided. However, only the corner cube 114 may be provided. Further, it is also possible to change the optical path length difference between the measurement optical path and the reference optical path by using an optical member other than these.

The reference light LR that has passed through the corner cube 114 passes through the dispersion compensating member 113 and the optical path length correction member 112, is converted from a parallel luminous flux to a focused luminous flux by the collimator 116, and is incident on the optical fiber 117. The reference light LR incident on the optical fiber 117 is guided by the polarization controller 118 to adjust the polarization state of the reference light LR.

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

On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and is converted into a parallel luminous flux by the collimator lens unit 40. The measurement light LS, which is a parallel luminous flux, is guided to the dichroic mirror 46 via the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, the mirror 44, and the relay lens 45. The measurement light LS guided to the dichroic mirror 46 is reflected by the dichroic mirror 46, refracted by the objective lens 22, and irradiated to the eye E to be inspected. The measurement light LS is scattered (including reflection) at various depth positions of the eye E to be inspected. The return light of the measurement light LS including such backscattered light travels in the same path as the outward path in the opposite direction, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

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

The detector 125 is, for example, a balanced photodiode (Balanced Photo Diode) that has a pair of photodetectors that detect each pair of interference light LCs and outputs the difference between the detection results by these. The detector 125 sends the detection result (interference signal) to the DAQ (Data Acquisition System) 130. A clock KC is supplied to the DAQ 130 from the light source unit 101. The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept (scanned) by the wavelength sweep type light source within the set wavelength range (wavelength sweep width). The light source unit 101 optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then sets the clock KC based on the result of detecting the combined light. Generate. The DATA 130 samples the detection result of the detector 125 based on the clock KC. The DAQ 130 sends the detection result of the sampled detector 125 to the arithmetic control unit 200. Further, the sampling timing may be changeable in order to deal with the case where the measurement range (shooting range) is changed. The DAQ130 may acquire the detection result of the detector 125 without using the clock KC. The arithmetic control unit 200 obtains a reflection intensity profile in each A line by, for example, performing a Fourier transform or the like on the spectral distribution based on the detection result obtained by the detector 125 for each series of wavelength scans (for each A line). Form. Further, the arithmetic control unit 200 can form image data by imaging the reflection intensity profile of each A line.

Before taking a picture or measuring the eye E to be inspected, the ophthalmic apparatus 1 performs alignment (XY alignment) in a direction orthogonal to the optical axis of the optical system (interference optical system) by a known method, and then aligns the optical axis. It is possible to perform alignment (Z alignment) in the direction.

When performing Z alignment, the ophthalmic apparatus 1 scans an area including at least a part of the front surface of the subject's face with the OCT unit 100 to acquire OCT information, and analyzes the acquired OCT information. Identify locations that correspond to at least a portion of the area. When the region includes the eye E to be inspected, the ophthalmologic apparatus 1 relatively moves the eye E to be inspected and the optical system of the apparatus based on the specified position. When the region does not include the eye E to be examined, the ophthalmologic apparatus 1 can relatively move the region of the subject's face and the device optical system based on the specified position.

Hereinafter, the ophthalmic apparatus 1 shall perform alignment in the optical axis direction of the apparatus optical system by relatively moving the cornea of the eye E to be inspected and the apparatus optical system. That is, the ophthalmic apparatus 1 scans the peripheral region of the eye E to be inspected including the cornea of the eye E to be inspected to acquire OCT information, and analyzes the acquired OCT information to obtain the position (depth) of the region corresponding to the cornea. Specify the position in the direction and the position in the z direction). The ophthalmic apparatus 1 relatively moves the cornea of the eye E to be inspected and the optical system of the apparatus using the specified position.

FIG. 4 shows an explanatory diagram of Z alignment in the ophthalmic apparatus 1 according to the embodiment. In FIG. 4, the same parts as those in FIGS. 2 and 3 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

For Z alignment, for example, a relative position between the surface of the objective lens 22 on the side of the eye to be inspected E and the cornea of the eye to be inspected E (for example, the apex of the cornea) is used. Specifically, the ophthalmic apparatus 1 specifies the distance in the z direction between the surface of the objective lens 22 and the cornea from this relative position, and covers the distance in the z direction so that the specified distance becomes a predetermined operating distance. The Z alignment is performed by relatively moving the optometry E and the optical system.

In this embodiment, as shown in FIG. 4, a predetermined intermediate point Zr is provided between the surface of the objective lens 22 on the side of the eye to be inspected E and the cornea of the eye to be inspected E. Thereby, the relative position is specified by the first relative position between the surface of the objective lens 22 on the eye E side and the intermediate point Zr and the second relative position between the intermediate point Zr and the cornea of the eye E to be inspected. Becomes possible. The intermediate point Zr is provided so that the second relative position can be specified by the OCT information. Specifically, as the intermediate point Zr, a position (position of the DC component) at which the optical path length of the reference light LR and the optical path length of the measurement light LS coincide with each other in the interference optical system is used. Hereinafter, in such an interference optical system, the position where the optical path length of the reference light LR and the optical path length of the measurement light LS coincide with each other is referred to as a zero position (OCT zero position).

In this case, the distance LL obtained from the first relative position can be specified by the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS in the interference optical system. The optical path length difference can be specified from the state of the optical path length changing unit (monitor value, etc.) or the control content for these. The state of the optical path length changing unit includes the position of the corner cube constituting the optical path length changing unit 41 for changing the optical path length of the measured optical LS, or the corner cube included in the optical path length changing unit for changing the optical path length of the reference optical LR. There are 114 positions and so on.

Further, the distance Lzd obtained from the second relative position can be specified from the position corresponding to the cornea with respect to the zero position by analyzing the OCT information. For example, the position zd in the depth direction of the region corresponding to the cornea with respect to the zero position as the intermediate point Zr is specified from the OCT image IMG as the OCT information. Therefore, the distance Lzd between the zero position and the cornea is uniquely obtained from the position zd. The ophthalmic apparatus 1 can perform the Z alignment by relatively moving the eye E to be inspected and the optical system of the apparatus in the z direction so that the distance (LL + Lzd) is the working distance of the objective lens 22.

The ophthalmology device 1 identifies the position of the surface of the objective lens 22 and the position of the corneal apex of the eye E to be inspected by a separately provided imaging means (or detection means), and distances LL from the two specified positions. May be asked.

[Calculation control unit]
The configuration of the arithmetic control unit 200 will be described. The arithmetic control unit 200 analyzes the interference signal input from the detector 125 to form an OCT image of the eye E to be inspected, and calculates the intraocular distance of the eye E to be inspected. The arithmetic processing for forming the OCT image and the processing for calculating the intraocular distance are the same as those of the conventional swept source type ophthalmic apparatus.

Further, 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 causes the display device 3 to display an OCT image of the eye to be inspected E, a calculation result of the intraocular distance, and the like.

The arithmetic control unit 200 includes, for example, a microprocessor, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, a communication interface, and the like, similarly to a conventional computer. A computer program for controlling the ophthalmic 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, circuit boards for forming OCT images. Further, 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.

[Control system]
The configuration of the control system (processing system) of the ophthalmic apparatus 1 will be described with reference to FIG. In FIG. 5, some components of the ophthalmic apparatus 1 are omitted, and components particularly necessary for explaining this embodiment are selectively shown.

(Control unit)
The arithmetic control unit 200 includes a control unit 210, an image forming unit 220, and a data processing unit 230. The control unit 210 includes, for example, a microprocessor, RAM, ROM, a hard disk drive, a communication interface, and the like. The control unit 210 is provided with a main control unit 211 and a storage unit 212.

(Main control unit)
The main control unit 211 performs the above-mentioned various controls. In particular, as shown in FIG. 5, the main control unit 211 controls the moving mechanisms 31A, 41A and 43A of the fundus camera unit 2, the CCD image sensors 35 and 38, the LCD 39, and the optical scanner 42. Further, the main control unit 211 controls the light source unit 101 of the OCT unit 100, the moving mechanism 114A, the detector 125, the DAQ 130, and the like.

The moving mechanism 31A moves the photographing focusing lens 31 along the optical axis of the photographing optical system 30. The moving mechanism 31A is provided with a holding member for holding the photographing focusing lens 31, an actuator for generating a driving force for moving the holding member, and a transmission mechanism for transmitting the driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. As a result, the moving mechanism 31A controlled by the control unit 210 moves the photographing focusing lens 31, so that the focusing position of the photographing optical system 30 is changed. The moving mechanism 31A may move the shooting focusing lens 31 along the optical axis of the shooting optical system 30 manually or by operating the user's operation unit 242.

The moving mechanism 41A moves the corner cubes constituting the optical path length changing unit 41 along the optical path of the measurement optical LS. The moving mechanism 41A is provided with a holding member for holding the corner cube, an actuator for generating a driving force for moving the holding member, and a transmission mechanism for transmitting the driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. As a result, the moving mechanism 41A controlled by the control unit 210 moves the corner cube, so that the optical path length of the measurement light LS is changed. The moving mechanism 41A may move the corner cube along the optical path of the measurement light LS either manually or by operating the user's operation unit 242.

The moving mechanism 43A moves the OCT focusing lens 43 along the optical path of the measurement light LS. The moving mechanism 43A is provided with a holding member for holding the OCT focusing lens 43, an actuator for generating a driving force for moving the holding member, and a transmission mechanism for transmitting the driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. As a result, the moving mechanism 43A controlled by the control unit 210 moves the OCT focusing lens 43, so that the focusing position of the measurement light LS is changed. The moving mechanism 43A may move the OCT focusing lens 43 along the optical path of the measurement light LS either manually or by operating the user's operation unit 242.

The optical system drive unit 1A drives a moving mechanism that three-dimensionally moves the device optical system shown in FIGS. 2 and 3. The moving mechanism is provided with a holding member that holds the device optical system, an actuator that generates a driving force for moving the holding member, and a transmission mechanism that transmits the driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. The main control unit 211 can control the optical system drive unit 1A to move the optical system provided in the ophthalmic apparatus 1 three-dimensionally. This control is used in alignment and tracking. Tracking is to move the device optical system according to the movement of the eye E to be inspected. When tracking is performed, alignment and focusing are performed in advance. Tracking maintains a suitable positional relationship in which alignment and focus are achieved by moving the device optical system in real time according to the position and orientation of the eye E to be inspected based on an image obtained by capturing a moving image of the eye E to be inspected. It is a function.

The moving mechanism 114A moves the corner cube 114 provided in the reference optical path. The moving mechanism 114A is provided with a holding member for holding the corner cube 114, an actuator for generating a driving force for moving the holding member, and a transmission mechanism for transmitting the driving force. As a result, the optical path length of the reference light LR is changed. The moving mechanism 114A may move the corner cube 114 along the reference optical path manually or by operating the user's operation unit 242.

(Memory)
The storage unit 212 stores various types of data. Examples of the data stored in the storage unit 212 include image data of an OCT image, image data of a fundus image, intraocular distance data of an eye to be inspected, and eye information to be inspected. The eye test information includes information about the subject such as the patient ID and name, and information about the test eye such as left eye / right eye identification information. In addition, various programs and data for operating the ophthalmic apparatus 1 are stored in the storage unit 212.

In this embodiment, the storage unit 212 stores in advance the correspondence information 212a for specifying the distance LL of FIG. Correspondence information 212a is information in which the information corresponding to the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS and the distance between the position of the objective lens 22 and the zero position are associated in advance. Here, as information corresponding to the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS, there are the position of the corner cube constituting the optical path length changing unit 41, the position of the corner cube 114, and the like. For example, the main control unit 211 specifies the position of the corner cube constituting the optical path length changing unit 41 and the position of the corner cube 114 from the control contents for the moving mechanism 41A or the moving mechanism 114A. The positions of the corner cubes constituting the optical path length changing unit 41 and the positions of the corner cubes 114 may be acquired from the detecting means for detecting them. Further, even if the main control unit 211 specifies the position of the corner cube constituting the optical path length changing unit 41 or the position of the corner cube 114 from the information acquired by accessing the moving mechanism 41A or the moving mechanism 114A. Good. Correspondence information 212a may be stored in the data processing unit 230.

(Image forming part)
The image forming unit 220 forms the image data of the tomographic image of the eye E to be inspected based on the interference signal from the detector 125 (DAQ130). That is, the image forming unit 220 forms the image data of the eye E to be inspected based on the detection result of the interference light LC by the interference optical system. This process includes processing such as noise removal (noise reduction), filter processing, and FFT (Fast Fourier Transform). The image data acquired in this way is a data set including a group of image data formed by imaging reflection intensity profiles in a plurality of A-lines.

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

Further, the image forming unit 220 produces two or more split optotype images from the image signal detected by the CCD 35 based on the return light of the two or more split optotypes from the eye E to be inspected that has passed through the photographing focusing lens 31. It is possible to form the depicted image. The main control unit 211 may form an image in which the two or more split optotype images are drawn.

The image forming unit 220 includes, for example, the circuit board described above. In this specification, "image data" and "image" based on the "image data" may be equated. In addition, the site of the eye E to be inspected and the image thereof may be equated.

(Data processing unit)
The data processing unit 230 performs various data processing (image processing) and analysis processing on the image formed by the image forming unit 220. For example, the data processing unit 230 executes correction processing such as image brightness correction and dispersion correction. In addition, the data processing unit 230 performs various image processing and analysis processing on the images (fundus image, anterior ocular segment image, etc.) obtained by the fundus camera unit 2.

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

The data processing unit 230 includes an analysis unit 231 and a distance specifying unit 232. Based on the interference signal obtained by the detector 125, the analysis unit 231 identifies a position corresponding to a region including at least a part (for example, pupil, cornea) of the front surface of the subject's face. The analysis unit 231 can also specify the position from the OCT image formed by the image forming unit 220 based on the interference signal. For example, the analysis unit 231 identifies the position corresponding to the zero position and the position of the region corresponding to the cornea by analyzing the OCT image in the optical axis direction of the device optical system. The analysis unit 231 may specify the position directly from the interference signal.

The distance specifying unit 232 specifies the distance LL in the z direction between the position of the objective lens 22 and the zero position based on the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS. Specifically, the distance specifying unit 232 receives the information corresponding to the above-mentioned optical path length difference acquired by the main control unit 211, and specifies the distance LL by referring to the corresponding information 212a based on the information. For example, the distance specifying unit 232 specifies the distance associated with the information corresponding to the above-mentioned optical path length difference in the corresponding information 212a as the distance LL. Further, the distance specifying unit 232 may specify the distance associated with the information corresponding to the optical path length difference closest to the optical path length difference in the corresponding information 212a as the distance LL. Alternatively, the distance specifying unit 232 may specify the distance LL by interpolating two or more distances associated with the information corresponding to the two or more optical path length differences close to the above optical path length difference in the corresponding information 212a. ..

The data processing unit 230 may calculate one or more intraocular distances of the eye E to be inspected based on the detection data of two or more interference light LCs by the interference optical system. The data processing unit 230 calculates the intraocular distance of the eye E to be inspected based on the distance between the positions of the two interference signals based on the two interference lights included in the detection data. Such a data processing unit 230 can calculate the corneal thickness, the depth of the anterior chamber, the lens thickness, the axial length, and the like.

The data processing unit 230 can align the fundus image and the OCT image. When the fundus image and the OCT image are acquired in parallel, since both optical systems are coaxial, the fundus image and the OCT image acquired at the same time (almost) are taken as the optical axis of the photographing optical system 30. Can be aligned with reference to. Further, regardless of the acquisition timing of the fundus image and the OCT image, the alignment of the fundus image with the front image obtained by projecting at least a part of the image region corresponding to the fundus Ef of the OCT image onto the xy plane is performed. By doing so, it is also possible to align the OCT image and the fundus image. This alignment method can be applied even when the optical system for acquiring a fundus image and the optical system for OCT are not coaxial. Even if both optical systems are not coaxial, if the relative positional relationship between the two optical systems is known, the same alignment as in the case of coaxial is executed with reference to this relative positional relationship. It is possible.

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

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

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

Of the optical systems shown in FIGS. 2 and 3, at least the optical system included in the OCT unit 100 is an example of the “optical system” according to the embodiment. The optical system drive unit 1A is an example of the “drive unit” according to the embodiment. The position corresponding to the cornea is an example of the "first position" according to the embodiment. The optical system included in the OCT unit 100 divides the light from the light source into the measurement light and the reference light, and causes the interference light to interfere with the return light of the measurement light from the eye to be inspected and the reference light passing through the reference optical path. This is an example of an "interference optical system" that is generated and detects this interference light. The zero position (OCT zero position) at the position where the optical path length of the reference light LR and the optical path length of the measurement light LS coincide with each other is an example of the “second position” according to the embodiment. The OCT unit 100, the image forming unit 220, or the photographing optical system 30 are examples of the “imaging unit” according to the embodiment. The distance between the surface of the objective lens 22 on the E side of the eye to be inspected and the intermediate point Zr is an example of the "first distance" according to the embodiment. The distance between the midpoint Zr and the cornea of the eye E to be inspected is an example of the "second distance" according to the embodiment.

[Operation example]
The operation of the ophthalmic apparatus 1 will be described. Examples of the operation of the ophthalmic apparatus 1 are shown in FIGS. 6 to 9. First, the correspondence information is registered before the alignment according to the embodiment is performed, and the above-mentioned alignment is performed using the registered correspondence information.

FIG. 6 shows a flow chart of an operation example of the ophthalmic apparatus 1 according to the embodiment. FIG. 6 shows an operation example of the correspondence information registration process. This registration process may be performed at the time of shipment of the ophthalmic apparatus 1 or at predetermined time intervals after shipment.

(S1)
First, the measurement sample (optical member) is arranged at a position separated from the objective lens 22 by a known predetermined distance DT. An example of a sample for measurement is a reflection mirror. The main control unit 211 controls the OCT unit 100 and the like to execute an OCT scan on the measurement sample and acquire OCT information. Specifically, the main control unit 211 turns on the light source unit 101 and controls the optical scanner 42 to start scanning the eye E to be inspected with the measurement light LS based on the light L0 from the light source unit 101. For example, the image forming unit 220 forms an OCT image as OCT information based on the detection result of the interference light by the detector 125 as described above.

(S2)
The main control unit 211 causes the analysis unit 231 to analyze whether or not the measurement sample is included in the predetermined measurement range (imaging range) from the OCT information acquired in S1. For example, the analysis unit 231 determines whether or not the position of the intensity of the return light of the measurement light LS reflected from the measurement sample is within a predetermined range, so that the measurement sample is included in the measurement range. It can be determined whether or not the sample is used. When it is determined that the measurement sample is included in the predetermined measurement range (S2: Y), the operation of the ophthalmic apparatus 1 shifts to S4. When it is determined that the measurement sample is not included in the predetermined measurement range (S2: N), the operation of the ophthalmic apparatus 1 shifts to S3.

(S3)
When it is determined from the OCT information acquired in S1 that the measurement sample is not included in the predetermined measurement range (S2: N), the main control unit 211 controls the moving mechanism 41A or the moving mechanism 114A. The optical path length of the reference light LR or the optical path length of the measurement light LS is changed by. As a result, the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS is changed, and the position of the return light of the measurement light LS reflected from the measurement sample in the OCT information changes in the z direction. For example, when the OCT information is an OCT image, the position of the region corresponding to the measurement sample drawn on the OCT image changes in the z direction. After that, the operation of the ophthalmic apparatus 1 shifts to S1.

(S4)
When it is determined from the OCT information acquired in S1 that the measurement sample is included in the predetermined measurement range (S2: Y), the main control unit 211 receives the OCT information based on the OCT information acquired in S1. The analysis unit 231 is made to specify the position of the region corresponding to the cornea of the eye examination E. The analysis unit 231 specifies the position in the depth direction of the region, and obtains the depth (distance in the z direction) of the position with reference to the zero position.

(S5)
Subsequently, the main control unit 211 subtracts the distance corresponding to the depth specified in S4 from the distance DT of S1 to obtain the distance between the objective lens and the zero position.

(S6)
The main control unit 211 sets the position of the current corner cube (corner cube or corner cube 114 constituting the optical path length changing unit 41) as information corresponding to the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS. Refer to. As described above, the main control unit 211 can specify the position of the corner cube constituting the optical path length changing unit 41 and the position of the corner cube 114 from the control contents for the moving mechanism 41A or the moving mechanism 114A.

(S7)
The main control unit 211 generates correspondence information by associating the distance between the objective lens zero positions obtained in S5 with the position of the corner cube specified in S6, and stores the correspondence information 212a in the storage unit 212.

(S8)
The main control unit 211 determines whether or not there is the next optical path length. When it is determined that there is the next optical path length (S8: Y), the operation of the ophthalmic apparatus 1 shifts to S9. When it is determined that there is no next optical path length (S8: N), the operation of the ophthalmic apparatus 1 ends (end).

(S9)
When it is determined that there is the next optical path length (S8: Y), the main control unit 211 controls the moving mechanism 41A or the moving mechanism 114A so that the optical path length difference is determined in advance. The optical path length of the optical path or the optical path length of the measured optical LS is changed. After that, the operation of the ophthalmic apparatus 1 shifts to S1.

As described above, the correspondence information 212a relating a plurality of optical path length differences MT ₁ , MT ₂ , MT ₃ , ... And the distance between the objective lens and the zero position LL ₁ , LL ₂ , LL _{3, ...} It is registered in the storage unit 212 (see FIG. 7).

Correspondence information may be registered for each of a plurality of known predetermined distances (see S1). In this case, when performing the alignment described later, one correspondence information can be selected from a plurality of correspondence information, and the distance between the objective lens and the zero position can be specified by using the selected correspondence information. Further, one objective lens / zero position replacement distance may be specified from a plurality of corresponding information. As a result, the distance between the objective lens and the zero position can be specified with high accuracy from the optical path length difference.

When the correspondence information 212a as shown in FIG. 7 is stored in the storage unit 212, the ophthalmic apparatus 1 can execute the alignment at an arbitrary timing.

8 and 9 show a flow chart of an operation example of alignment in the ophthalmic apparatus 1 according to the embodiment.

(S20)
The main control unit 211 moves the optical system to the initial position by controlling the optical system drive unit 1A. The initial position may be such that the distance between the eye E to be inspected and the objective lens 22 is sufficiently larger than the working distance of the objective lens 22. As a result, it becomes easy to identify the alignment target position (corneal position) from a wide area including the eye E to be inspected.

(S21)
Next, the main control unit 211 causes the photographing optical system 30 to photograph the peripheral portion of the eye E to be inspected, and causes the photographing optical system 30 to acquire a plane image of the eye E to be inspected. The plane image acquired in S21 may be an xy plane image generated from OCT information acquired by using the OCT unit 100, a projection image, or the like.

(S22)
The main control unit 211 causes the analysis unit 231 to specify the feature portion from the plane image acquired in S21. Characteristic sites include the cornea (pupil) and the like. For example, the analysis unit 231 identifies the corneal region by a known method.

(S23)
By controlling the optical system drive unit 1A, the main control unit 211 optics in the xy direction so that the center of the cornea from the specified corneal region becomes the center (position of the optical axis) of the plane image acquired in S21. Move the system (XY alignment).

(S24)
Subsequently, the main control unit 211 turns on the light source unit 101 and controls the optical scanner 42 to start scanning the eye E to be inspected with the measurement light LS based on the light L0 from the light source unit 101. For example, the image forming unit 220 forms an OCT image based on the detection result of the interference light by the detector 125 as described above.

(S25)
The main control unit 211 causes the analysis unit 231 to analyze whether or not the region corresponding to the cornea of the eye E to be inspected is included in the predetermined measurement range (imaging range) from the OCT information acquired in S24. For example, the analysis unit 231 measures the region corresponding to the cornea by determining whether or not the position of the intensity of the return light of the measurement light LS reflected from the cornea of the eye E to be inspected is included in a predetermined range. It can be determined whether or not it is included in the range. When it is determined that the region corresponding to the cornea of the eye E to be inspected is included in the predetermined measurement range (S25: Y), the operation of the ophthalmic apparatus 1 shifts to S27. When it is determined that the region corresponding to the cornea of the eye E to be inspected is not included in the predetermined measurement range (S25: N), the operation of the ophthalmic apparatus 1 shifts to S26.

(S26)
When it is determined from the OCT information acquired in S24 that the region corresponding to the cornea of the eye E to be inspected is not included in the predetermined measurement range (S25: N), the main control unit 211 moves the moving mechanism 41A or the moving mechanism 41A. By controlling the mechanism 114A, the optical path length of the reference light LR or the optical path length of the measurement light LS is changed. As a result, the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS is changed, and the position of the return light of the measurement light LS reflected from the cornea of the eye E to be inspected in the OCT information changes in the z direction. For example, when the OCT information is an OCT image, the position of the region corresponding to the cornea of the eye E to be inspected drawn on the OCT image changes in the z direction. After that, the operation of the ophthalmic apparatus 1 shifts to S24.

(S27)
When it was determined from the OCT information acquired in S24 that the region corresponding to the cornea of the eye E to be inspected was included in the predetermined measurement range (S25: Y), the main control unit 211 was acquired in S24. Based on the OCT information, the analysis unit 231 is made to specify the position of the region corresponding to the cornea of the eye E to be inspected. The analysis unit 231 specifies the position in the depth direction of the region, and obtains the depth (distance in the z direction) of the position with reference to the zero position.

(S28)
Subsequently, the main control unit 211 provides the current corner cube (corner cube or corner cube 114 constituting the optical path length changing unit 41) as information corresponding to the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS. ), The correspondence information 212a is referred to.

(S29)
The main control unit 211 specifies the distance between the objective lens and the zero position from the correspondence information 212a. The main control unit 211 adds the distance between the specified objective lens zero position and the distance corresponding to the depth specified in S27 to the surface of the objective lens 22 on the eye E side to be inspected and the eye E to be inspected. Calculate the distance between the objective lens and the cornea, which is the distance between the optometry. The distance between the objective lens and the cornea may be obtained by the distance specifying unit 232.

(S30)
The main control unit 211 compares the distance between the objective lens and the cornea calculated in S29 with the operating distance of the objective lens 22.

(S31)
The main control unit 211 obtains the difference between the distance between the objective lens and the cornea and the operating distance of the objective lens 22, and determines whether or not the difference is equal to or less than a predetermined target value. This target value corresponds to the permissible value of the amount of deviation of Z alignment. When it is determined that the difference is equal to or less than the target value (S31: Y), the operation of the ophthalmic apparatus 1 ends (end).

When it is determined that the difference is equal to or less than the target value (S31: Y), the main control unit 211 determines that the adjustment of the relative positional relationship between the eye to be inspected E and the optical system of the apparatus is completed, and the measurement light is measured. The OCT imaging system may be adjusted such as the focus position of the LS and the polarization state. When adjusting the OCT imaging system, the main control unit 211 executes an OCT scan on the eye E to be inspected to form an OCT image, and changes the optical path length so that the contrast of the image in the region of interest is maximized. Each part of 41 and OCT unit 100 can be controlled. For example, the main control unit 211 moves the position of the corner cube (corner cube or corner cube 114 constituting the optical path length changing unit 41) to adjust the optical path length difference, or uses the moving mechanism 31A to adjust the optical path length difference, or the photographing focusing lens 31 by the moving mechanism 31A. And change the polarization state by controlling the polarization controllers 103 and 118.

When it is determined in S31 that the difference is not less than or equal to the target value (S31: N), the operation of the ophthalmic apparatus 1 shifts to S32.

(S32)
When it is determined in S31 that the difference is not equal to or less than the target value (S31: N), the main control unit 211 moves the device optical system in the z direction by controlling the optical system drive unit 1A. After that, the operation of the ophthalmic apparatus 1 shifts to S24.

[effect]
The effect of the ophthalmic apparatus according to the embodiment will be described.

The ophthalmic apparatus (1) according to the embodiment includes an optical system (an optical system included in the OCT unit 100 and an optical system through which measurement light passes), a driving unit (optical system driving unit 1A), and an analysis unit (232). , A control unit (210, main control unit 211). The optics are used to collect data by scanning an area containing at least a portion of the anterior surface of the subject's face using optical coherence tomography. The drive unit relatively moves the eye to be inspected (E) and the optical system in the optical axis direction (z direction) of the optical system. The analysis unit identifies a first position (position corresponding to the cornea) corresponding to at least a part of the above region based on the data collected by the optical system. The control unit relatively moves the eye to be inspected and the optical system by controlling the drive unit based on the first position specified by the analysis unit.

According to such a configuration, an area including at least a part of the front surface of the subject's face is scanned using OCT, and a position corresponding to at least a part of the area is specified based on the collected data. However, since the drive unit was controlled based on the specified position to move the eye to be inspected and the optical system relative to each other, the information obtained by OCT was used to align the direction of the optical axis of the optical system. It becomes possible to do. As a result, it is not necessary to provide an optical system dedicated to alignment, and the ophthalmic apparatus can be miniaturized. Further, since the positional relationship between the front surface of the subject's face and the device can be grasped, it is possible to adjust the position between the subject and the optical system while ensuring safety.

Further, in the ophthalmic apparatus according to the embodiment, the optical system may include an objective lens (22) and an interference optical system. The interference optical system divides the light (L0) from the light source (light source unit 101) into the reference light (LR) and the measurement light (LS), and irradiates the test eye with the measurement light through the objective lens to test the eye. The interference light (LC) between the return light of the measurement light from and the reference light is detected. The analysis unit identifies the first position based on the detection result of the interference light detected by the interference optical system, and the control unit determines the position of the objective lens, the first position, the optical path length of the reference light, and the measurement light. The eye to be inspected and the optical system may be relatively moved based on the second position (zero position, position of the DC component) that coincides with the optical path length.

According to such a configuration, the position of the objective lens, the first position based on the detection result of the interference light in the interference optical system, and the second position where the optical path length of the reference light and the optical path length of the measurement light match. Since the alignment is performed using the optical system, it is possible to perform the alignment in the direction of the optical axis of the optical system without providing an optical system dedicated to the alignment.

Further, in the ophthalmic apparatus according to the embodiment, the control unit has a first distance between the position of the objective lens and the second position, and a position corresponding to the second position and the first position in the detection result of the interference light. The eye to be inspected and the optical system may be moved relative to each other based on the second distance between them.

According to such a configuration, the alignment is performed using the first distance and the second distance that can be specified from the information obtained by the OCT. Therefore, the optical system does not need to be provided with an optical system dedicated to the alignment. It is possible to perform alignment in the direction of the optical axis of.

Further, in the ophthalmic apparatus according to the embodiment, the control unit relatively moves the eye to be inspected and the optical system so that the sum of the first distance and the second distance becomes a predetermined working distance (working distance of the objective lens 22). You may let me.

According to such a configuration, it is possible to perform alignment in the direction of the optical axis of the optical system without providing an optical system dedicated to alignment.

Further, in the ophthalmic apparatus according to the embodiment, the interference optical system is an optical path length changing unit (41 or an optical path length changing unit including a corner cube 114) that relatively changes the optical path length of the reference light and the optical path length of the measurement light. ), And a distance specifying unit (232) that specifies the first distance based on the optical path length difference between the optical path of the reference light and the optical path of the measurement light changed by the optical path length changing unit may be included.

According to such a configuration, the first distance is specified based on the optical path length difference between the optical path of the reference light and the optical path of the measurement light. Therefore, OCT is used without providing an optical system dedicated to alignment. It is possible to perform alignment in the optical axis direction of the optical system only with the acquired information.

Further, in the ophthalmic apparatus according to the embodiment, the optical path length changing portion may include a corner cube that is arranged in the optical path of the reference light or the optical path of the measurement light and can move along the optical path.

According to such a configuration, it is possible to simplify the configuration and control of the ophthalmic apparatus capable of aligning the direction of the optical axis of the optical system by using the information obtained by OCT.

Further, the ophthalmic apparatus according to the embodiment includes a storage unit (212) that stores in advance the corresponding information (212a) in which the information corresponding to the optical path length difference and the first distance are associated with each other, and the distance specifying unit is stored in the storage unit. The first distance may be specified based on the stored correspondence information.

According to such a configuration, it is possible to provide an ophthalmic apparatus capable of highly accurate alignment in the direction of the optical axis of the optical system without providing an optical system dedicated to alignment.

Further, the optometry apparatus according to the embodiment includes an imaging unit (imaging optical system 30) that photographs at least a part of the above region, and the driving unit is in a direction (xy direction) that intersects the optical axis direction of the optical system. The eye to be inspected and the optical system are relatively moved, and the control unit relatively moves the eye to be inspected and the optical system in a direction intersecting the optical axis direction of the optical system based on the captured image obtained by the photographing unit. After that, the eye to be inspected and the optical system may be relatively moved in the optical axis direction based on the first position.

According to such a configuration, it is possible to provide an ophthalmic apparatus capable of aligning the direction of the optical axis of the optical system using the information obtained by OCT and capable of aligning in the direction intersecting the optical axis. Will be able to.

Further, the ophthalmic apparatus according to the embodiment includes a support portion (440) that supports the face, and the drive portion may move the support portion and the optical system relative to each other.

According to such a configuration, an ophthalmic apparatus capable of performing highly accurate alignment of the subject's face supported by the support portion and the optical system in that direction using the information obtained by OCT. Will be able to provide.

Also, in the ophthalmic apparatus according to the embodiment, the optical system may scan the area including the cornea, eyelids, nose, or cheeks.

With such a configuration, the information obtained by OCT can be used to perform alignment of the optical system with the area including the cornea, eyelids, nose, or cheeks of the subject.

<Modification example>
The configuration described above is only an example for preferably carrying out the present invention. Therefore, any modification (omission, substitution, addition, etc.) within the scope of the gist of the present invention can be appropriately applied.

In the above embodiment, the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS is changed by changing the position of the corner cube. It is not limited. For example, the difference in optical path length may be changed by moving the fundus camera unit 2 or the OCT unit 100 with respect to the eye E to be inspected and changing the optical path length of the measurement light LS.

Further, when safety is ensured, it is possible to change the optical path length difference by moving the subject's face or the like in the z direction. For example, a jaw receiving drive unit that moves the support unit 440 in at least the z direction under the control of the main control unit 211 may be provided. The jaw receiving drive may also be movable in the xy direction.

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

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

1 Ophthalmology device 2 Fundus camera unit 1A Optical system drive unit 10 Illumination optical system 30 Imaging optical system 31 Focusing lens 41 Optical path length changing unit 41A, 114A Moving mechanism 42 Optical scanner 100 OCT unit 114 Corner cube 200 Arithmetic control unit 210 Control unit 211 Main control unit 212 Storage unit 212a Corresponding information 220 Image formation unit 230 Data processing unit 231 Analysis unit 232 Distance identification unit 240 User interface 241 Display unit 242 Operation unit 410 Base 420 Housing 430 Lens housing unit 440 Support unit E Eye to be inspected LS Measurement light LR Reference light LC Interference light

Claims (9)

An optical system for collecting data by scanning an area containing at least a portion of the anterior surface of the subject's face using optical coherence tomography.
A drive unit that relatively moves the eye to be inspected and the optical system in the optical axis direction of the optical system.
An analysis unit that identifies a first position corresponding to at least a part of the region based on the data collected by the optical system.
A control unit that relatively moves the eye to be inspected and the optical system by controlling the drive unit based on the first position specified by the analysis unit.
Only including,
The optical system is
With the objective lens
The light from the light source is divided into a reference light and a measurement light, the measurement light is irradiated to the eye to be inspected through the objective lens, and the return light of the measurement light from the eye to be inspected interferes with the reference light. Interfering optical system that detects light and
Including
The analysis unit identifies the first position based on the detection result of the interference light detected by the interference optical system.
The control unit sets the eye to be inspected and the optical system based on the position of the objective lens, the first position, and the second position where the optical path length of the reference light and the optical path length of the measurement light coincide with each other. An ophthalmic device that moves the lens relative to each other. The control unit has a first distance between the position of the objective lens and the second position, and a second position between the position corresponding to the second position and the first position in the detection result of the interference light. based on the distance, the ophthalmologic apparatus according to claim 1, wherein the relatively moving the eye and said optical system. The ophthalmology according to claim 2, wherein the control unit relatively moves the eye to be inspected and the optical system so that the sum of the first distance and the second distance becomes a predetermined working distance. apparatus. The interference optical system includes an optical path length changing unit that relatively changes the optical path length of the reference light and the optical path length of the measurement light.
Claim 2 or characterized in that it comprises a distance specifying unit for specifying said first distance based on the optical path length difference between the optical path of the measurement light and the optical path of the reference light changed by the optical path length changing unit The ophthalmic apparatus according to claim 3. The ophthalmic apparatus according to claim 4, wherein the optical path length changing unit includes a corner cube that is arranged in the optical path of the reference light or the optical path of the measurement light and can move along the optical path. A storage unit that stores in advance the corresponding information in which the information corresponding to the optical path length difference and the first distance are associated with each other is included.
The distance specifying unit, wherein the claim 4 or wherein the identifying the first distance based on the correspondence information stored in the storage unit ophthalmic device according to claim 5. An optical system for collecting data by scanning an area containing at least a portion of the anterior surface of the subject's face using optical coherence tomography.
A drive unit that relatively moves the eye to be inspected and the optical system in the optical axis direction of the optical system.
An analysis unit that identifies a first position corresponding to at least a part of the region based on the data collected by the optical system.
A control unit that moves the eye to be inspected and the optical system relative to each other by controlling the drive unit based on the first position specified by the analysis unit.
A photographing unit that photographs at least a part of the area, and a photographing unit.
It includes,
The driving unit relatively moves the eye to be inspected and the optical system in a direction intersecting the optical axis direction of the optical system.
The control unit relatively moves the eye to be inspected and the optical system in a direction intersecting the optical axis direction of the optical system based on the captured image obtained by the imaging unit, and then moves to the first position. based the relatively moving the eye and said optical system to said optical axis direction, ophthalmology device. Includes a support that supports the face
The ophthalmic apparatus according to any one of claims 1 to 7, wherein the driving unit relatively moves between the support unit and the optical system. The ophthalmic apparatus according to any one of claims 1 to 8, wherein the optical system scans an area including a cornea, an eyelid, a nose, or a cheek.

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