JP2020151096A - Ophthalmologic apparatus - Google Patents

Abstract

To provide a novel technology to achieve, for example, the positioning between the ocular fundus of an eye to be examined and an apparatus optical system by a simple configuration and simple processing.SOLUTION: An ophthalmologic apparatus includes an optical system, an acquisition unit, an analysis unit, and a control unit. The optical system includes an optical scanner and irradiates an eye to be examined with the light deflected by the optical scanner. The acquisition unit acquires an anterior eye part image of the eye to be examined. The analysis unit specifies a cornea incident position where the light is incident in the cornea of the eye to be examined, and a rotation angle of the eye to be examined by analyzing the anterior eye part image acquired by the acquisition unit, and specifies a retina incident position where the light is incident in the retina of the eye to be examined based on the cornea incident position and the rotation angle. The control unit controls the optical scanner based on the displacement of the retina incident position relative to a reference position in the retina.SELECTED DRAWING: Figure 4

Description

Embodiments of the present invention relate to ophthalmic devices.

The ophthalmologic apparatus includes an ophthalmologic imaging apparatus for obtaining an image of the eye to be inspected, an ophthalmologic measuring apparatus for measuring the characteristics of the eye to be inspected, and an ophthalmic treatment apparatus for treating 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 optics (SLO), slit lamp microscopes, surgical microscopes, and the like.

Examples of ophthalmic measuring devices include an ophthalmic refraction tester (refractive meter, keratometer) that measures the refractive characteristics of the eye to be inspected, an tonometer, a specular microscope that obtains corneal characteristics (corneal thickness, cell distribution, etc.), and the like. There are wavefront analyzers that use the Hartmann-Shack sensor to obtain information on the aberration of the eye to be inspected, and perimeters and microperimeters that measure the visual field condition.

Examples of ophthalmic treatment devices include a laser treatment device that projects a laser beam onto a treatment target site such as a diseased part, a surgical device for a specific purpose (cataract surgery, corneal refraction correction surgery, etc.), a surgical microscope, and the like. ..

In an ophthalmic device, from the viewpoint of the accuracy and accuracy of the test, the alignment (alignment, tracking) between the device optical system and the eye to be inspected is extremely important not only before the start of the test but also during the test.

For example, Patent Document 1 discloses a method of projecting a luminous flux onto the cornea, detecting a reflected image (Pulkiner image) thereof, and performing alignment.

For example, in Patent Document 2, the amount of movement of the fundus is obtained from the fundus observation images acquired periodically, and the measurement light is always irradiated to the same region of the fundus by controlling the optical scanner according to the obtained amount of movement. A method of correcting the scanning position so as to be performed is disclosed.

For example, Patent Document 3 discloses a method of identifying a three-dimensional position of an eye to be inspected from two or more captured images obtained by photographing the anterior segment from different directions and performing alignment based on the three-dimensional position. Has been done.

Japanese Unexamined Patent Publication No. 8-275921 Japanese Unexamined Patent Publication No. 2013-153793 Japanese Unexamined Patent Publication No. 2013-248376

However, the conventional method requires an illumination system for observing the retina (fundus). As a result, the configuration of the optical system becomes complicated, which leads to an increase in size and cost of the optical system. In particular, when the optical paths of a plurality of optical systems are optically coupled, it may be difficult to separate the wavelengths of the light used in each optical system, the optical design may be complicated, and it may be difficult to add an optical system. Since the addition of such an optical system requires an optical element for synthesizing or separating light, the amount of light required for measurement in each optical system is lowered, and the measurement accuracy is lowered.

Further, since the process for obtaining the amount of movement of the fundus as disclosed in Patent Document 2 includes the pattern matching process, the processing load becomes heavy.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a new technique for realizing, for example, the alignment of the fundus of the eye to be inspected with the optical system of the device with a simple configuration and processing. To do.

A first aspect of some embodiments comprises an optical scanner, an optical system that irradiates the eye to be examined with light deflected by the optical scanner, an acquisition unit that acquires an image of the anterior segment of the eye to be examined, and the acquisition. By analyzing the anterior segment image acquired by the unit, the corneal incident position where the light is incident and the rotation angle of the eye to be inspected are identified in the retina of the eye to be inspected, and the corneal incident position and the rotation angle are determined. Based on this, the analysis unit that identifies the retinal incident position where the light is incident on the retina of the eye to be inspected and the optical scanner is controlled based on the displacement of the retinal incident position with respect to the reference position on the retina. It is an ophthalmic apparatus including a control unit for retina.

In a second aspect of some embodiments, in the first aspect, the analysis unit identifies the rotation angle based on the displacement of a position corresponding to the featured portion of the eye to be inspected in the anterior segment image.

In a third aspect of some embodiments, in the first or second aspect, the analysis unit has at least one of a rotation angle in the first plane and a rotation angle in the second plane that intersects the first plane. To identify.

In a fourth aspect of some embodiments, in any of the first to third aspects, the analysis unit determines the rotation angle using an eye parameter representing the optical properties of the eye to be inspected or a predetermined model eye. Identify.

A fifth aspect of some embodiments comprises an alignment optical system that projects an alignment luminous flux onto the eye to be inspected in any of the first to fourth aspects, the analysis unit said in the anterior eye image. The corneal incident position is specified based on the image formed based on the alignment luminous flux.

A sixth aspect of some embodiments includes, in a fifth aspect, a moving mechanism that relatively moves the eye to be inspected and the optical system, the control unit being directed to the alignment luminous flux in the anterior segment image. After controlling the moving mechanism based on the image formed based on the above, the optical scanner is controlled based on the displacement.

In the seventh aspect of some embodiments, in the sixth aspect, the acquisition unit includes two or more imaging units that photograph the anterior segment of the eye from different directions substantially simultaneously, and the control unit is the control unit. The movement mechanism is controlled based on the positions of the above-mentioned imaging units and the positions of the images obtained by analyzing two or more captured images acquired by the two or more imaging units.

In the eighth aspect of some embodiments, in any of the first to seventh aspects, the analysis unit optics the eye under test or a predetermined model eye with respect to the light incident on the corneal incident position. The retinal incident position is specified by performing a ray tracing process using an eyeball parameter representing the characteristic.

In the ninth aspect of some embodiments, in any of the first to eighth aspects, the control unit in the retina with respect to a predetermined change in the incident angle of the light at the corneal incident position. Control information is specified by repeating the ray tracing process so that the amount of change in the displacement of the retina incident position with respect to the reference position is within a predetermined threshold value, and the optical scanner is controlled based on the control information.

In the tenth aspect of some embodiments, in any of the first to eighth aspects, the control unit uses table information or functions corresponding to the optical characteristics of the eye to be inspected or a predetermined model eye. The amount of change in the incident angle of the light at the corneal incident position is specified, the control information is specified based on the specified amount of change, and the optical scanner is controlled based on the control information.

In the eleventh aspect of some embodiments, in the fourth, eighth, or tenth aspect, the optical property comprises corneal shape information of the eye to be inspected.

In the twelfth aspect of some embodiments, in the eleventh aspect, the optical system includes a corneal shape measuring optical system that projects a measurement pattern onto the eye to be inspected and detects a return light thereof, and the corneal shape measuring optical system. It includes a corneal shape information calculation unit that calculates the corneal shape information of the eye to be inspected based on the detection result of the return light obtained by the system.

In the thirteenth aspect of some embodiments, in any of the fourth, tenth to twelfth aspects, the optical property comprises the refractive power value of the eye to be inspected.

In the 14th aspect of some embodiments, in the 13th aspect, the optical system includes a refractive power measuring optical system that projects light onto the eye to be inspected and detects the return light thereof, and the optical power measuring optical system. Includes a refractive power value calculation unit that calculates the refractive power value of the eye to be inspected based on the detection result of the return light obtained in the above.

In the fifteenth aspect of some embodiments, in any of the fourth, tenth to fourteenth aspects, the optical property comprises an intraocular distance of the eye to be inspected.

In the 16th aspect of some embodiments, in the 15th aspect, the optical system divides the light from the light source into a reference light and a measurement light, and the measurement light deflected by the optical scanner is used as the eye to be inspected. The eye of the eye to be inspected includes an OCT optical system that is projected onto the eye to detect interference light between the return light from the eye to be inspected and the reference light, and is based on the detection result of the interference light obtained by the OCT optical system. Includes an intraocular distance calculation unit that calculates the internal distance.

In the 17th aspect of some embodiments, in the 16th aspect, the analysis unit identifies the reference position based on the detection result of the interference light obtained by the OCT optical system.

In the eighteenth aspect of some embodiments, in any of the first to fifteenth aspects, the optical system divides the light from the light source into reference light and measurement light and deflects the light from the optical scanner. The analysis unit includes the OCT optical system that projects the measurement light onto the eye to be inspected and detects the interference light between the return light from the eye to be inspected and the reference light, and the analysis unit is the interference obtained by the OCT optical system. The reference position is specified based on the light detection result.

It is possible to arbitrarily combine the configurations according to the above-mentioned plurality of aspects.

According to the present invention, for example, it is possible to provide a new technique for realizing the alignment between the fundus of the eye to be inspected and the optical system of the apparatus by a simple process and process.

It is the schematic which shows an example of the structure of the optical system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the optical system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the optical system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the processing system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the processing system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the processing system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the processing system of the ophthalmic apparatus which concerns on embodiment. It is a schematic diagram for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is a schematic diagram for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is a schematic diagram for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is a schematic diagram for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is a schematic diagram for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is a schematic diagram for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is the schematic 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 includes an acquisition unit that acquires an image of the anterior segment of the eye to be inspected, and an optical system that includes an optical scanner and irradiates the eye to be inspected (for example, fundus and retina) with light deflected by the optical scanner. To be equipped with. The optical system according to some embodiments is configured to irradiate the eye to be inspected with light deflected by an optical scanner and detect the return light. Examples of the optical system according to the embodiment include a refractive power measurement optical system, a corneal shape measurement optical system, an OCT optical system, an SLO optical system, and a laser irradiation optical system.

The ophthalmic apparatus identifies (estimates) the retinal incident position where light from the optical system is incident on the retina (fundus) from the anterior segment image of the eye to be inspected, and an optical scanner based on the displacement of the retinal incident position with respect to the reference position on the retina. To control. At this time, the retina incident position is specified with high accuracy by reflecting the rotation (rotation) of the eye to be inspected. In some embodiments, the corneal incident position where light from the optical system is incident on the cornea and the rotation angle of the eye to be inspected are identified from the anterior segment image of the eye to be inspected and are based on the identified corneal incident position and rotation angle. The position of incidence on the retina is identified. The reference position on the retina may be specified from a detection result (for example, a tomographic image) obtained by another optical system, or may be specified by a user using an operation unit. In some embodiments, the rotation angle of the eye to be inspected is calculated from the displacement of the featured portion of the eye to be inspected in the anterior segment image. As a result, the optical scanner can be controlled around a desired position on the retina without observing the retina, so that the optical system can be aligned with high accuracy with respect to the position. .. Such control can be used for alignment and tracking between the eye to be inspected and the optical system.

Hereinafter, a case where the ophthalmic apparatus according to the embodiment mainly performs tracking by using the above method will be described.

The ophthalmic apparatus according to the embodiment can perform measurement and imaging using OCT. The ophthalmic apparatus according to some embodiments can perform at least one of corneal shape measurement (kerato measurement) and refractive power measurement (ref measurement) in addition to OCT measurement and the like.

Hereinafter, in the embodiment, the case where the swept source type OCT method is used in the measurement using OCT will be described in particular, but for an ophthalmic apparatus using another type (for example, spectral domain type) OCT, It is also possible to apply the configuration according to the embodiment.

Ophthalmic devices according to some embodiments further include a subjective test optical system for performing a subjective test and other objective measurement systems for performing objective measurements.

The subjective test is a measurement method for acquiring information by using the response from the subject. The subjective test includes a distance test, a near test, a contrast test, a glare test, and other subjective refraction measurements, and a visual field test.

Objective measurement is a measurement method for acquiring information about an eye to be examined mainly by using a physical method without referring to a response from the subject. Objective measurement includes measurement for acquiring the characteristics of the eye to be inspected and photographing for acquiring an image of the eye to be inspected. Other objective measurements include intraocular pressure measurement, fundus photography and the like.

Hereinafter, the fundus conjugate position is a position that is optically conjugated to the fundus of the eye to be inspected in the state where the alignment is completed, and means a position that is optically conjugated to the fundus of the eye to be inspected or its vicinity. Similarly, the pupil-conjugated position is a position that is optically conjugated to the pupil of the eye to be inspected in the state where the alignment is completed, and means a position that is optically conjugated to the pupil of the eye to be inspected or its vicinity. ..

<Composition of optical system>
FIG. 1 shows a configuration example of an optical system of an ophthalmic apparatus according to an embodiment. The ophthalmic apparatus 1000 according to the embodiment includes an optical system for observing the eye E to be inspected, an optical system for inspecting the eye E to be inspected, and a dichroic mirror for wavelength-separating the optical paths of these optical systems. An anterior segment observation (photographing) system 5 is provided as an optical system for observing the eye E to be inspected. An OCT optical system, a ref measurement optical system (refractive power measurement optical system), and the like are provided as an optical system for inspecting the eye E to be inspected.

The ophthalmic apparatus 1000 includes an alignment light projection system 2, a kerato measurement system 3, a fixation projection system 4, an anterior segment observation system 5, a reflex measurement projection system 6, a reflex measurement light receiving system 7, and an OCT optical system 8. In the following, for example, the anterior segment observation system 5 mainly uses light of 940 nm to 1000 nm, and the reflex measurement optical system (ref measurement projection system 6, reflex measurement light receiving system 7) uses light of 830 nm to 880 nm for fixation. It is assumed that the projection system 4 uses light of 400 nm to 700 nm and the OCT optical system 8 uses light of 1000 nm to 1100 nm.

(Anterior segment observation system 5)
The anterior segment observation system 5 captures a moving image of the anterior segment of the eye E to be inspected. In the optical system passing through the anterior segment observation system 5, the image pickup surface of the image pickup device 59 is arranged at the pupil conjugate position. The anterior segment illumination light source 50 irradiates the anterior segment of the eye E to be inspected with illumination light (for example, infrared light). The light reflected by the anterior segment of the eye E to be inspected passes through the objective lens 51, passes through the dichroic mirror 52, passes through the hole formed in the diaphragm (teresen diaphragm) 53, and passes through the half mirror 23. , Passes through the relay lenses 55 and 56, and passes through the dichroic mirror 76. The dichroic mirror 52 synthesizes (separates) the optical path of the reflex measurement optical system and the optical path of the anterior segment observation system 5. In the dichroic mirror 52, the optical path synthesis surface that synthesizes these optical paths is arranged so as to be inclined with respect to the optical axis of the objective lens 51. The light transmitted through the dichroic mirror 76 is imaged on the image pickup surface of the image pickup element 59 (area sensor) by the image pickup lens 58. The image sensor 59 performs image pickup and signal output at a predetermined rate. The output (video signal) of the image sensor 59 is input to the processing unit 9 described later. The processing unit 9 displays the anterior segment image E'based on this video signal on the display screen 10a of the display unit 10 described later. The anterior segment image E'is, for example, an infrared moving image. The anterior segment image E'may be acquired using the anterior segment camera 300 described later.

(Alignment light projection system 2)
The alignment light projection system 2 aligns the anterior segment observation system 5 in the optical axis direction (front-back direction, Z direction) and in the direction orthogonal to the optical axis (horizontal direction (X direction), vertical direction (Y direction)). (Infrared light) is applied to the eye E to be examined. The alignment light projection system 2 includes an alignment light source 21 and a collimator lens 22 provided in an optical path branched from the optical path of the anterior segment observation system 5 by a half mirror 23. The light output from the alignment light source 21 passes through the collimator lens 22, is reflected by the half mirror 23, and is projected onto the eye E to be inspected through the anterior segment observation system 5. The reflected light from the corneal Cr of the eye E to be inspected is guided to the image sensor 59 through the anterior segment observation system 5.

The image (bright spot image) Br based on this reflected light is included in the anterior segment image E'. The processing unit 9 displays the anterior segment image E'including the bright spot image Br and the alignment mark AL on the display screen of the display unit. When manually performing XY alignment, the user can perform an operation of moving the optical system so as to guide the bright spot image Br in the alignment mark AL. When the Z alignment is manually performed, the user can perform the movement operation of the optical system while referring to the anterior segment image E'displayed on the display screen of the display unit. When performing automatic alignment, the processing unit 9 satisfies a predetermined alignment completion condition based on the position of a predetermined portion (for example, the center position of the pupil) of the eye to be inspected E and the position of the bright spot image Br, as will be described later. The mechanism for moving the optical system is controlled so as to.

(Kerato measurement system 3)
The kerato measurement system 3 projects a ring-shaped luminous flux (infrared light) for measuring the shape of the cornea Cr of the eye E to be inspected onto the cornea Cr. The kerato plate 31 is arranged between the objective lens 51 and the eye E to be inspected. A keratling light source 32 is provided on the back side (objective lens 51 side) of the kerato plate 31. By illuminating the kerato plate 31 with the light from the kerat ring light source 32, a ring-shaped obtained luminous flux (arc-shaped or circumferential-shaped measurement pattern) is projected on the cornea Cr of the eye E to be inspected. The reflected light (keratling image) from the corneal Cr of the eye E to be inspected is detected by the image sensor 59 together with the anterior segment image E'. The processing unit 9 calculates a corneal shape parameter representing the shape of the corneal Cr by performing a known calculation based on this keratling image.

(Ref measurement projection system 6, reflex measurement light receiving system 7)
The reflex measurement optical system includes a reflex measurement projection system 6 and a reflex measurement light receiving system 7 used for measuring the refractive power of the eye. The reflex measurement projection system 6 projects a luminous flux for measuring the refractive power of the eye (for example, a ring-shaped luminous flux) (infrared light) onto the fundus Ef. The reflex measurement light receiving system 7 receives the return light of this luminous flux from the eye E to be inspected. The reflex measurement projection system 6 is provided in an optical path branched by a perforated prism 65 provided in the optical path of the reflex measurement light receiving system 7. The hole formed in the perforated prism 65 is arranged at the pupil conjugate position. In the optical system that passes through the reflex measurement light receiving system 7, the image pickup surface of the image pickup device 59 is arranged at the fundus conjugate position.

In some embodiments, the ref measurement light source 61 is an SLD (Superluminescent Diode) light source, which is a high-intensity light source. The reflex measurement light source 61 is movable in the optical axis direction. The reflex measurement light source 61 is arranged at the fundus conjugate position. The light output from the reflex measurement light source 61 passes through the relay lens 62 and is incident on the conical surface of the conical prism 63. The light incident on the conical surface is deflected and emitted from the bottom surface of the conical prism 63. The light emitted from the bottom surface of the conical prism 63 passes through the translucent portion formed in a ring shape on the ring diaphragm 64. The light (ring-shaped luminous flux) that has passed through the translucent portion of the ring diaphragm 64 is reflected by the reflecting surface formed around the hole portion of the perforated prism 65, passes through the rotary prism 66, and is reflected by the dichroic mirror 67. To. The light reflected by the dichroic mirror 67 is reflected by the dichroic mirror 52, passes through the objective lens 51, and is projected onto the eye E to be inspected. The rotary prism 66 is used for averaging the light amount distribution of the ring-shaped luminous flux with respect to the blood vessels and diseased parts of the fundus Ef and reducing speckle noise caused by the light source.

The return light of the ring-shaped luminous flux projected on the fundus Ef passes through the objective lens 51 and is reflected by the dichroic mirror 52 and the dichroic mirror 67. The return light reflected by the dichroic mirror 67 passes through the rotary prism 66, passes through the hole portion of the perforated prism 65, passes through the relay lens 71, is reflected by the reflection mirror 72, and is reflected by the relay lens 73 and the focusing lens. Pass through 74. The focusing lens 74 can move along the optical axis of the reflex measurement light receiving system 7. The light that has passed through the focusing lens 74 is reflected by the reflection mirror 75, reflected by the dichroic mirror 76, and imaged on the image pickup surface of the image pickup element 59 by the image pickup lens 58. The processing unit 9 calculates the eye refractive power (eye refractive power value) of the eye E to be inspected by performing a known calculation based on the output from the image sensor 59. For example, the ocular refractive power includes spherical power, astigmatic power and astigmatic axis angle, or equivalent spherical power.

(Focus projection system 4)
An OCT optical system 8 described later is provided in an optical path whose wavelength is separated from the optical path of the ref measurement optical system by a dichroic mirror 67. The fixation projection system 4 is provided in the optical path branched from the optical path of the OCT optical system 8 by the dichroic mirror 83.

The fixation projection system 4 presents the fixation target to the eye E to be inspected. The fixation unit 40 is arranged in the optical path of the fixation projection system 4. The fixation unit 40 can move along the optical path of the fixation projection system 4 under the control of the processing unit 9 described later. The fixation unit 40 includes a liquid crystal panel 41.

The liquid crystal panel 41 controlled by the processing unit 9 displays a pattern representing a fixation target. By changing the display position of the pattern on the screen of the liquid crystal panel 41, the fixation position of the eye E to be inspected can be changed. The fixation position of the eye E to be inspected includes a position for acquiring an image centered on the macula of the fundus Ef, a position for acquiring an image centered on the optic nerve head, and a position between the macula and the optic disc. There is a position for acquiring an image centered on the center of the fundus between them. It is possible to arbitrarily change the display position of the pattern representing the fixation target.

The light from the liquid crystal panel 41 passes through the relay lens 42, passes through the dichroic mirror 83, passes through the relay lens 82, is reflected by the reflection mirror 81, passes through the dichroic mirror 67, and is reflected by the dichroic mirror 52. .. The light reflected by the dichroic mirror 52 passes through the objective lens 51 and is projected onto the fundus Ef. In some embodiments, each of the liquid crystal panel 41 and the relay lens 42 can move independently in the optical axis direction.

Instead of the liquid crystal panel 41, a transmission type optotype chart for reflex measurement in which an optotype or the like is printed on a film or the like, an illumination light source for illuminating the optotype chart, and a point light source for OCT measurement are used. It may be provided.

FIG. 2 shows another configuration example of the fixation projection system 4 according to the embodiment. In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The fixation unit 40 provided in the fixation projection system 4 according to this example is provided with an illumination light source 45a, an optotype chart 46a, and a fixation light source 47a in place of the liquid crystal panel 41. The fixation light source 47a, the optotype chart 46a, and the relay lens 42 are arranged in this order from the illumination light source 45a toward the dichroic mirror 83. The optotype chart 46a is a transmissive optotype chart that is arranged between the illumination light source 45a and the eye E to be inspected and represents a landscape chart. In some embodiments, the optotype chart 46a is a transmissive film on which a landscape chart is printed. In some embodiments, the fixation light source 47a is a point light source having a predetermined emission size.

The illumination light source 45a is turned on when the ref measurement described later is performed, and the landscape chart is projected onto the eye E to be inspected by illuminating the optotype chart 46a with the light from the illumination light source 45a. When the OCT measurement described later is performed, the fixation light source 47a is turned on, and a bright spot (dot target) (second fixation target) having a narrower viewing angle than the landscape chart is projected onto the eye E to be inspected. In some embodiments, the fixation light source 47a is turned off when the ref measurement is performed, and the illumination light source 45a is turned off when the OCT measurement is performed. As a result, the landscape chart is presented to the eye E to be inspected when the reflex measurement is performed, and the bright spot is presented to the eye E to be inspected when the OCT measurement is performed.

In some embodiments, the fixation light source 47a is controlled to blink when performing an OCT measurement. In some embodiments, a plurality of fixation light sources 47a are provided, and by selectively lighting the plurality of fixation light sources 47a, the projection position of the bright spot is changed or moved.

The ophthalmic apparatus 1000 shown in FIG. 1 is provided with two or more anterior segment cameras 300 for photographing the anterior segment of the eye E to be inspected from different directions. In this embodiment, two anterior segment cameras are provided on the surface of the ophthalmic apparatus 1000 facing the subject, but the number of anterior segment cameras according to the embodiment is any number of 2 or more. .. As shown in FIG. 1, each of the two anterior segment cameras is from the optical axis of the objective lens 51 (the optical path (optical axis) of the anterior segment observation system 5 and the optical path (optical axis) of the OCT optical system 8). It is installed in a detached position. Hereinafter, the two cameras may be collectively represented by reference numeral 300.

In this embodiment, the anterior segment camera 300 is provided separately from the anterior segment observation system 5, but at least the anterior segment observation system 5 can be used to perform the same anterior segment observation. In some embodiments, one of the two or more anterior segment cameras includes an anterior segment observation system 5 (imaging element 59). The ophthalmic apparatus 1000 according to the embodiment may be configured so that the anterior segment can be photographed from two or more different directions.

In some embodiments, at least one frontal illumination light source 50 (infrared light source, etc.) can be provided in the vicinity of each of the two or more frontal cameras. For example, an anterior segment illumination light source provided near one upper side of the anterior segment camera 300, an anterior segment illumination light source provided near the lower portion, and a front portion provided near the other upper portion of the anterior segment camera 300. An eye illumination light source and an anterior eye illumination light source provided near the lower part are provided.

Two or more anterior segment cameras can image the anterior segment substantially simultaneously from two or more different directions. “Substantially at the same time” means that, for example, in imaging with two or more anterior segment cameras, a shift in imaging timing to the extent that eye movements can be ignored is allowed. Thereby, an image when the eye E to be inspected is in substantially the same position (orientation) can be acquired by two or more anterior eye cameras.

Further, the shooting with two or more front eye cameras may be a moving image shooting or a still image shooting. In the case of moving image shooting, it is possible to realize substantially simultaneous front eye shooting as described above by controlling the shooting start timing to be adjusted, and controlling the frame rate and the shooting timing of each frame. .. On the other hand, in the case of still image shooting, this can be realized by controlling the shooting timing to be adjusted.

(OCT optical system 8)
The OCT optical system 8 shown in FIG. 1 is an optical system for performing OCT measurement. For example, the position of the focusing lens 87 is adjusted so that the end face of the optical fiber f1 is conjugated to the imaging site (fundus Ef or anterior ocular segment) and the optical system based on the result of the ref measurement performed before the OCT measurement. Will be done. Alternatively, for example, the position of the focusing lens 87 is adjusted so that the intensity of the interference signal obtained by the OCT measurement is maximized.

The OCT optical system 8 is provided in an optical path whose wavelength is separated from the optical path of the reflex measurement optical system by a dichroic mirror 67. The optical path of the fixation projection system 4 is coupled to the optical path of the OCT optical system 8 by the dichroic mirror 83. As a result, the optical axes of the OCT optical system 8 and the fixation projection system 4 can be coaxially coupled.

The OCT optical system 8 includes an OCT unit 100. As shown in FIG. 2, in the OCT unit 100, the OCT light source 101 is a wavelength sweep type (wavelength scanning type) light source capable of sweeping (scanning) the wavelength of emitted light, similarly to a general swept source type OCT device. Consists of including. The wavelength sweep type light source is configured to include a laser light source including a resonator. The OCT light source 101 changes the output wavelength with time in a near-infrared wavelength band that is invisible to the human eye.

As illustrated in FIG. 3, the OCT unit 100 is provided with an optical system for performing Swept Source OCT. This optical system includes an interference optical system. This interference optical system has a function of dividing the light from the variable wavelength light source (wavelength sweep type light source) into the measurement light and the reference light, and the return light of the measurement light from the eye E to be inspected and the reference light via the reference optical path. It has a function of generating interference light by superimposing the lights and a function of detecting the interference light. The detection result (detection signal, interference signal) of the interference light obtained by the interference optical system is a signal showing the spectrum of the interference light and is sent to the processing unit 9.

The OCT light source 101 includes, for example, a near-infrared wavelength tunable laser that changes the wavelength of emitted light (wavelength range of 1000 nm to 1100 nm) at high speed. The light L0 output from the OCT light source 101 is guided by the optical fiber 102 to the polarization controller 103, and its polarization state is adjusted. The light L0 whose polarization state is adjusted 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, converted into a parallel luminous flux, and guided to the corner cube 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with the optical path length of the measurement light LS. The dispersion compensating member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS. The corner cube 114 is movable in the incident direction of the reference light LR, thereby changing the optical path length of the reference light LR.

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

On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber f1 and converted into a parallel light beam by the collimator lens unit 89, and passes through the optical scanner 88, the focusing lens 87, the relay lens 85, and the reflection mirror 84. Then, it is reflected by the dichroic mirror 83.

The optical scanner 88 deflects the measurement light LS one-dimensionally or two-dimensionally. The optical scanner 88 includes, for example, a first galvano mirror and a second galvano mirror. The first galvano mirror deflects the measurement light LS so as to scan the imaging region (fundus Ef or anterior segment) in the horizontal direction orthogonal to the optical axis of the OCT optical system 8. The second galvano mirror deflects the measurement light LS deflected by the first galvano mirror so as to scan the imaging region in the direction perpendicular to the optical axis of the OCT optical system 8. Examples of the scanning mode of the measured optical LS by the optical scanner 88 include horizontal scanning, vertical scanning, cross scanning, radial scanning, circular scanning, concentric circular scanning, and spiral scanning.

The measurement light LS reflected by the dichroic mirror 83 passes through the relay lens 82, is reflected by the reflection mirror 81, is transmitted through the dichroic mirror 67, is reflected by the dichroic mirror 52, is refracted by the objective lens 51, and is refracted by the objective lens 51. Incident in. The measurement light LS is scattered and reflected at various depth positions of the eye E to be inspected. The return light of the measurement light LS from the eye E to be inspected travels in the same direction as the outward path in the opposite direction, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

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

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

A clock KC is supplied to the DAQ 130 from the OCT light source 101. The clock KC is generated in the OCT light source 101 in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the tunable light source. The OCT light source 101 optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then sets the clock KC based on the result of detecting the combined light. Generate. The DATA 130 samples the detection signal input from the detector 125 based on the clock KC. The DATA 130 sends the sampling result of the detection signal from the detector 125 to the arithmetic processing unit 220 of the processing unit 9. The arithmetic processing unit 220 forms 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 sampling data for each series of wavelength scans (for each A line). Further, the arithmetic processing unit 220 forms image data by imaging the reflection intensity profile of each A line.

In this example, the corner cube 114 for changing the length of the optical path (reference optical path, reference arm) of the reference optical path LR is provided, but the measured optical path length and the reference optical path length are provided by using optical members other than these. It is also possible to change the difference with.

The processing unit 9 calculates the ocular refractive index from the measurement result obtained by using the reflex measurement optical system, and based on the calculated ocular refractive index, the fundus Ef, the reflex measurement light source 61, and the image pickup element 59 are coupled. The refraction measurement light source 61 and the focusing lens 74 are each moved in the optical axis direction to the position. In some embodiments, the processing unit 9 moves the focusing lens 87 of the OCT optical system 8 in the optical axis direction in conjunction with the movement of the focusing lens 74. In some embodiments, the processing unit 9 moves the liquid crystal panel 41 (fixation unit 40) in the optical axis direction in conjunction with the movement of the reflex measurement light source 61 and the focusing lens 74.

<Processing system configuration>
The configuration of the processing system of the ophthalmic apparatus 1000 will be described. Examples of the functional configuration of the processing system of the ophthalmic apparatus 1000 are shown in FIGS. 4 to 7. FIG. 4 shows an example of a functional block diagram of the processing system of the ophthalmic apparatus 1000. FIG. 5 shows an example of a functional block diagram of the data processing unit 225. FIG. 6 shows an example of a functional block diagram of the alignment processing unit 350 of FIG. FIG. 7 shows an example of a functional block diagram of the tracking processing unit 360 of FIG.

The processing unit 9 controls each unit of the ophthalmic apparatus 1000. In addition, the processing unit 9 can execute various arithmetic processes. The processing unit 9 includes a processor. The functions of the processor are, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a SPLD (Simple Programmable)) , FPGA (Field Programmable Gate Array)) and the like. The processing unit 9 realizes the function according to the embodiment by reading and executing, for example, a program stored in a storage circuit or a storage device.

The processing unit 9 is an example of the "ophthalmic information processing device" according to the embodiment. The program for realizing the function of the processing unit 9 is an example of the "ophthalmic information processing program" according to the embodiment.

The processing unit 9 includes a control unit 210 and an arithmetic processing unit 220. Further, the ophthalmic apparatus 1000 includes a moving mechanism 200, a display unit 270, an operation unit 280, and a communication unit 290.

The moving mechanism 200 includes optical systems such as an alignment light projection system 2, a kerato measurement system 3, a fixation projection system 4, an anterior segment observation system 5, a reflex measurement projection system 6, a reflex measurement light receiving system 7, and an OCT optical system 8. It is a mechanism for moving the head portion in which the device optical system is housed in the front-back and left-right directions. For example, the moving mechanism 200 is provided with an actuator that generates a driving force for moving the head portion 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 and a rack and pinion. The control unit 210 (main control unit 211) controls the moving mechanism 200 by sending a control signal to the actuator.

Control over the moving mechanism 200 is used in alignment and tracking. Tracking is to move the device optical system according to the eye movement of the eye E to be inspected. When performing tracking, alignment and focus adjustment are performed in advance. Tracking is a function of maintaining a suitable positional relationship in which alignment and focus are achieved by making the position of the optical system of the device follow the movement of the eyeball.

(Control unit 210)
The control unit 210 includes a processor and controls each unit of the ophthalmic apparatus 1000. The control unit 210 includes a main control unit 211, a storage unit 212, and an optical system position acquisition unit 213. The function of the optical system position acquisition unit 213 may be realized by the main control unit 211. A computer program for controlling the ophthalmic apparatus 1000 is stored in the storage unit 212 in advance. The computer program includes a light source control program, a detector control program, an optical scanner control program, an optical system control program, an alignment control program, a tracking control program, an arithmetic processing program, a user interface program, and the like. Is done. When the main control unit 211 operates according to such a computer program, the control unit 210 executes the control process.

The main control unit 211 controls various ophthalmic devices as a measurement control unit.

The control for the alignment light projection system 2 includes the control of the alignment light source 21 and the like. The control of the alignment light source 21 includes turning on and off the light source, adjusting the amount of light, adjusting the aperture, and the like. As a result, the alignment light source 21 is switched between lighting and non-lighting, and the amount of light is changed.

The control for the kerato measurement system 3 includes the control of the kerat ring light source 32 and the like. Control of the keratling light source 32 includes turning on and off the light source, adjusting the amount of light, adjusting the aperture, and the like. As a result, the keratling light source 32 is switched between lighting and non-lighting, and the amount of light is changed. The main control unit 211 causes the arithmetic processing unit 220 to perform a known calculation on the keratling image detected by the image sensor 59. As a result, the corneal shape parameter of the eye E to be inspected is obtained.

Controls for the fixation projection system 4 include control of the liquid crystal panel 41 and movement control of the fixation unit 40. The control of the liquid crystal panel 41 includes turning on / off the display of the fixation target, switching the display position of the fixation target, and the like.

For example, the fixation projection system 4 is provided with a moving mechanism for moving the liquid crystal panel 41 (or fixation unit 40) in the optical axis direction. Similar to the moving mechanism 200, the moving mechanism is provided with an actuator that generates a driving force for moving the moving mechanism and a transmission mechanism that transmits the driving force. The main control unit 211 controls the moving mechanism by sending a control signal to the actuator, and at least moves the liquid crystal panel 41 in the optical axis direction. As a result, the position of the liquid crystal panel 41 is adjusted so that the liquid crystal panel 41 and the fundus Ef are optically conjugated.

When the fixation projection system 4 is configured as shown in FIG. 2, the control for the fixation projection system 4 includes movement control of the fixation unit 40, control of the illumination light source 45a, and control of the fixation light source 47a. There is control and so on. Control of the illumination light source 45a includes turning on and off the light source, adjusting the amount of light, and the like. Control of the fixation light source 47a includes turning on and off the light source, adjusting the amount of light, and the like.

Control of the anterior segment observation system 5 includes control of the anterior segment illumination light source 50, control of the image pickup element 59, and the like. Control of the anterior segment illumination light source 50 includes turning on and off the light source, adjusting the amount of light, adjusting the aperture, and the like. As a result, the lighting of the forearm illumination light source 50 can be switched between lighting and non-lighting, and the amount of light can be changed. Control of the image sensor 59 includes exposure adjustment, gain adjustment, and detection rate adjustment of the image sensor 59. The main control unit 211 captures the signal detected by the image sensor 59, and causes the arithmetic processing unit 220 to perform processing such as forming an image based on the captured signal.

Controls for the front eye camera 300 include synchronous control of shooting start timings of two or more front eye cameras and shooting timings of each frame, exposure adjustment, gain adjustment, and frame rate adjustment of each front eye camera. .. As a result, the anterior segment of the eye E to be inspected is photographed substantially simultaneously.

The control for the reflex measurement projection system 6 includes the control of the reflex measurement light source 61, the control of the rotary prism 66, and the like. The control of the reflex measurement light source 61 includes turning on and off the light source, adjusting the amount of light, adjusting the aperture, and the like. As a result, the reflex measurement light source 61 can be switched between lighting and non-lighting, and the amount of light can be changed. For example, the reflex measurement projection system 6 includes a moving mechanism that moves the reflex measurement light source 61 in the optical axis direction. Similar to the moving mechanism 200, the moving mechanism is provided with an actuator that generates a driving force for moving the moving mechanism and a transmission mechanism that transmits the driving force. The main control unit 211 controls the movement mechanism by sending a control signal to the actuator, and moves the reflex measurement light source 61 in the optical axis direction. Control of the rotary prism 66 includes rotation control of the rotary prism 66 and the like. For example, a rotation mechanism for rotating the rotary prism 66 is provided, and the main control unit 211 rotates the rotary prism 66 by controlling the rotation mechanism.

Control of the reflex measurement light receiving system 7 includes control of the focusing lens 74 and the like. Control of the focusing lens 74 includes control of movement of the focusing lens 74 in the optical axis direction. For example, the reflex measurement light receiving system 7 includes a moving mechanism that moves the focusing lens 74 in the optical axis direction. Similar to the moving mechanism 200, the moving mechanism is provided with an actuator that generates a driving force for moving the moving mechanism and a transmission mechanism that transmits the driving force. The main control unit 211 controls the moving mechanism by sending a control signal to the actuator, and moves the focusing lens 74 in the optical axis direction. The main control unit 211 illuminates the reflex measurement light source 61 and the focusing lens 74, respectively, so that the reflex measurement light source 61, the fundus Ef, and the image pickup element 59 are optically coupled to each other, for example, according to the refractive power of the eye E to be inspected. It can be moved in the axial direction.

The control for the OCT optical system 8 includes the control of the OCT light source 101, the control of the optical scanner 88, the control of the focusing lens 87, the control of the corner cube 114, the control of the detector 125, the control of the DAQ 130, and the like. Control of the OCT light source 101 includes turning on and off the light source, adjusting the amount of light, adjusting the aperture, and the like. The control of the optical scanner 88 includes control of the scanning position, scanning range, and scanning speed by the first galvanometer mirror, control of the scanning position, scanning range, and scanning speed by the second galvanometer mirror.

The control of the focusing lens 87 includes control of movement of the focusing lens 87 in the optical axis direction, control of movement of the focusing lens 87 to the focusing reference position corresponding to the imaging region, and movement range corresponding to the imaging region (focusing). There is movement control within the focal range). For example, the OCT optical system 8 includes a moving mechanism that moves the focusing lens 87 in the optical axis direction. Similar to the moving mechanism 200, the moving mechanism is provided with an actuator that generates a driving force for moving the moving mechanism and a transmission mechanism that transmits the driving force. The main control unit 211 controls the moving mechanism by sending a control signal to the actuator, and moves the focusing lens 87 in the optical axis direction. In some embodiments, the ophthalmic apparatus 1000 is provided with a holding member that holds the focusing lenses 74 and 87 and a driving unit that drives the holding member. The main control unit 211 controls the movement of the focusing lenses 74 and 87 by controlling the drive unit. For example, the main control unit 211 may move the focusing lens 87 in conjunction with the movement of the focusing lens 74, and then move only the focusing lens 87 based on the intensity of the interference signal.

The control of the corner cube 114 includes movement control along the optical path of the corner cube 114. For example, the OCT optical system 8 includes a moving mechanism that moves the corner cube 114 in a direction along an optical path. Similar to the moving mechanism 200, the moving mechanism is provided with an actuator that generates a driving force for moving the moving mechanism and a transmission mechanism that transmits the driving force. The main control unit 211 controls the moving mechanism by sending a control signal to the actuator, and moves the corner cube 114 in the direction along the optical path. The control of the detector 125 includes exposure adjustment, gain adjustment, detection rate adjustment, detection signal data transfer control, and the like of the detection element. The main control unit 211 samples the signal detected by the detector 125 by the DAQ 130, and causes the arithmetic processing unit 220 (image forming unit 224) to perform processing such as forming an image based on the sampled signal.

The main control unit 211 can perform a plurality of preliminary operations before performing the OCT measurement. Preliminary operations include focus adjustment and polarization adjustment. For example, the focus adjustment is performed based on the interference sensitivity of the OCT measurement. For example, as described above, the focus adjustment can be performed by finding the position of the focusing lens 87 that maximizes the interference intensity and moving the focusing lens 87 to that position. In the polarization adjustment, the polarization state of the reference light LR is adjusted in order to optimize the interference efficiency between the measurement light LS and the reference light LR.

Further, as a display control unit, the main control unit 211 includes a measured value of the ocular refractive index calculated by the ocular refractive index calculation unit 221, a parameter representing the corneal shape calculated by the corneal shape calculation unit 222, and an intraocular parameter described later. , The tomographic image formed by the image forming unit 224 and the information corresponding to the processing result of the data processing unit 225 described later are displayed on the display unit 270.

Further, the main control unit 211 performs a process of writing data to the storage unit 212 and a process of reading data from the storage unit 212.

(Memory unit 212)
The storage unit 212 stores various types of data. The data stored in the storage unit 212 includes, for example, objective measurement results, OCT measurement measurement results, tomographic image data, anterior segment image image data, eye test information, aberration information described later, and described later. There is model eye data (standard value data). The eye test information includes information related to the test eye such as left eye / right eye identification information.

The aberration information includes a parameter that quantifies the distortion that occurs in the captured image due to the influence of the optical system, corresponding to each front eye camera 300. Parameters related to the distortion that the optical system gives to the captured image include the principal point distance, the principal point position (vertical direction, horizontal direction), and lens distortion (radiation direction, tangential direction). For example, the aberration information is configured as information (for example, table information) in which the identification information of each anterior segment camera 300 and the corresponding correction coefficient are associated with each other.

Further, the storage unit 212 stores an intraocular parameter 212A representing the optical characteristics of the eyeball. The intraocular parameter 212A according to some embodiments includes parameters of an eye model such as a known model eye. Further, the intraocular parameter 212A may include the parameter shown in FIG. 10 described later. Known model eyes include Gullstrand model eyes and Helmholtz model eyes. Such parameters include size parameters, shape parameters and optical parameters. The size parameter represents the size of part or all of the eye. The shape parameter represents the shape of the part of the eye. Optical parameters represent the optical function of the part of the eye.

Examples of parameters include axial length data, anterior chamber depth data, crystalline lens shape data representing the shape of the crystalline lens (lens curvature, lens thickness, etc.), corneal shape data representing the shape of the cornea (corneal radius of curvature, corneal thickness, etc.), etc. There is. At least a part of the intraocular parameter 212A may be replaced with the measured value (or the value obtained from the measured value) of the eye E to be inspected. The measured values of the eye E to be inspected (for example, the refractive power of the eye, the corneal shape parameter, the axial length) are acquired by the ophthalmic apparatus 1000 or an external device. In some embodiments, the above parameters are obtained from an electronic medical record system, a medical image archiving system, an external device, or the like.

In addition, various programs and data for operating the ophthalmic apparatus are stored in the storage unit 212.

(Optical system position acquisition unit 213)
The optical system position acquisition unit 213 is mounted on the ophthalmic apparatus 1000 and acquires the current position of the above-mentioned optical system for optically acquiring the data of the eye E to be inspected.

For example, the optical system position acquisition unit 213 receives information representing the content of the movement control of the movement mechanism 200 from the main control unit 211, and acquires the current position of the device optical system shown in FIG. In this case, the main control unit 211 controls the moving mechanism 200 at a predetermined timing (when the device is started, when the patient information is input, etc.) to move the device optical system to a predetermined initial position. After that, each time the main control unit 211 controls the moving mechanism 200, the control content is recorded. As a result, a history of control contents can be obtained. The optical system position acquisition unit 213 acquires the control contents up to the present with reference to this history, and obtains the current position of the apparatus optical system based on the control contents.

In some embodiments, each time the main control unit 211 controls the moving mechanism 200, the control content is transmitted to the optical system position acquisition unit 213. The optical system position acquisition unit 213 sequentially obtains the current position of the device optical system each time the control content is received.

In some embodiments, the optical system position acquisition unit 213 includes a position sensor that detects the position of the device optical system.

The main control unit 211 can control the movement mechanism 200 based on the current position acquired by the optical system position acquisition unit 213 and the movement target position determined by the data processing unit 225 described later. Thereby, the device optical system can be moved to the moving target position. For example, the main control unit 211 obtains the difference between the current position and the movement target position. This difference value is, for example, a vector value starting from the current position and ending at the moving target position. This vector value is, for example, a three-dimensional vector value represented by the XYZ coordinate system.

(Calculation processing unit 220)
The arithmetic processing unit 220 includes an eye refractive power calculation unit 221, a corneal shape calculation unit 222, an image formation unit 224, and a data processing unit 225.

The function of the arithmetic processing unit 220 is realized by one or more processors. In this case, a program that realizes the function of the arithmetic processing unit 220 is stored in a storage device or the like (storage unit 212), and one or more processors execute processing according to the corresponding program.

(Eye Refractive Power Calculation Unit 221)
The ocular refractive power calculation unit 221 receives a ring image (pattern image) obtained by the image pickup device 59 receiving the return light of the ring-shaped luminous flux (ring-shaped measurement pattern) projected on the fundus Ef by the reflex measurement projection system 6. ) Is analyzed. For example, the eye refractive power calculation unit 221 obtains the position of the center of gravity of the ring image from the brightness distribution in the image in which the obtained ring image is drawn, and obtains the brightness distribution along a plurality of scanning directions extending radially from this center of gravity position. , The ring image is specified from this brightness distribution. Subsequently, the eye refractive error calculation unit 221 obtains an approximate ellipse of the specified ring image, and substitutes the major axis and the minor axis of the approximate ellipse into a known equation to obtain the spherical power, the astigmatic power, and the astigmatic axis angle (eye). Refractive error). Alternatively, the eye refractive power calculation unit 221 can obtain the parameter of the eye refractive power based on the deformation and displacement of the ring image with respect to the reference pattern.

(Cornea shape calculation unit 222)
The corneal shape calculation unit 222 analyzes the keratling image obtained by the image sensor 59 receiving the return light of the ring-shaped luminous flux projected on the cornea Cr of the eye E to be inspected by the kerato measurement system 3. Calculate the corneal shape information of E.

The corneal shape information includes, for example, any parameter value representing the shape of the cornea that can be measured using a known ophthalmic apparatus. Typically, the corneal shape information includes radius of curvature (curvature), orientation of the strong main meridian, radius of curvature along the strong main meridian (frequency), orientation of the weak main meridian, radius of curvature along the weak main meridian (frequency), It may include any of ellipticity, eccentricity, flatness, topograph including irregular anomaly, and aberration information using the Zernike polymorphism.

For example, the corneal shape calculation unit 222 calculates the corneal radius of curvature of the strong and weak main meridians on the anterior surface of the cornea by analyzing the obtained keratling image, and a parameter representing the shape of the cornea based on the radius of curvature of the cornea. Is calculated. The corneal shape calculation unit 222 calculates the corneal radius of curvature by performing arithmetic processing on the obtained keratling image, and calculates the corneal refractive power, corneal astigmatism, and corneal astigmatism axis angle from the calculated corneal radius of curvature. can do.

(Image forming unit 224)
The image forming unit 224 forms the image data of the tomographic image of the fundus Ef based on the signal detected by the detector 125. That is, the image forming unit 224 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 filtering and FFT (Fast Fourier Transform), as in the case of the conventional spectral domain type OCT. The image data acquired in this way is a data set including a group of image data formed by imaging the reflection intensity profile in a plurality of A lines (paths of each measurement light LS in the eye E to be inspected). is there.

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.

For example, the function of the image forming unit 224 is realized by an image forming processor. In this case, a program that realizes the function of the image forming unit 224 is stored in a storage device or the like (storage unit 212), and the image forming processor executes the process according to the corresponding program.

(Data processing unit 225)
The data processing unit 225 performs various data processing (image processing) and analysis processing on the tomographic image formed by the image forming unit 224. For example, the data processing unit 225 executes correction processing such as image brightness correction and dispersion correction. In addition, the data processing unit 225 performs various image processing and analysis processing on the image (anterior eye portion image and the like) obtained by using the anterior segment observation system 5.

For example, the data processing unit 225 performs a predetermined analysis process on the detection result of the interference light obtained by the OCT measurement or the OCT image formed based on the detection result. In the predetermined analysis process, the predetermined site (tissue, lesion) in the eye E to be examined is specified; the distance between the designated sites (interlayer distance), the area, the angle, the ratio, and the density are calculated; the designated formula is used. Calculation by; Identification of the shape of a predetermined part; Calculation of these statistical values; Calculation of the distribution of measured values and statistical values; Image processing based on these analysis processing results and the like. Predetermined tissues include blood vessels, optic discs, retinas, fovea centralis, macula and the like. Predetermined lesions include vitiligo, bleeding, and the like.

The data processing unit 225 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 225 performs rendering processing on the volume data to form a pseudo three-dimensional image when viewed from a specific line-of-sight direction.

As shown in FIG. 5, the data processing unit 225 includes an alignment processing unit 350 and a tracking processing unit 360.

The alignment processing unit 350 performs data processing for performing alignment of the device optical system with reference to a characteristic portion (for example, the center of the pupil) in the anterior segment of the eye based on two or more captured images obtained by the anterior segment camera 300. I do. After the alignment based on the processing result of the alignment processing unit 350 is completed, the tracking processing unit 360 continues the state in which the alignment of the device optical system is performed with respect to the eye E to be inspected by the deflection control of the optical scanner 88 ( Perform data processing for (alignment in a broad sense). The tracking processing unit 360 identifies the retinal incident position where the measurement light LS is incident from the anterior segment image while considering the rotation of the eye E to be inspected, and sets the optical scanner 88 based on the displacement of the retinal incident position with respect to the reference position on the retina. Performs data processing for control. The retinal incident position is a position where the measurement light LS is incident on a predetermined layer region (for example, any layer from the inner limiting membrane to the retinal pigment epithelial layer) in the retina (fundus Ef). The retinal incident position may be a position where the measurement light LS is incident on the choroid.

(Alignment processing unit 350)
As shown in FIG. 6, the alignment processing unit 350 moves with the image correction unit 351, the Pulkiner image identification unit 352, the Pulkiner image position identification unit 353, the pupil center identification unit 354, and the pupil center position identification unit 355. Includes a target position determination unit 356.

(Image correction unit 351)
The image correction unit 351 corrects the distortion of the captured image obtained by the anterior segment camera 300. The image correction unit 351 can correct the distortion of the captured image based on the aberration information stored in the storage unit 212. This process is performed, for example, by a known image processing technique based on a correction factor for correcting distortion. If the distortion that the optical system of the anterior segment camera 300 gives to the captured image is sufficiently small, the aberration information and the image correction unit 351 may not be provided.

(Pulkinje image identification part 352)
The main control unit 211 turns on, for example, the alignment light source 21. As a result, the alignment luminous flux is projected onto the anterior segment of the eye, and a Purkinje image is formed. The Pulkinje image is formed at a position deviated in the axial direction (Z direction) from the apex of the cornea by a distance of half the radius of curvature of the cornea.

The anterior segment to which the alignment luminous flux is projected is photographed substantially simultaneously by the two anterior segment cameras 300. The two captured images acquired substantially at the same time by the two front eye cameras 300 are corrected by the image correction unit 351 as necessary and input to the Purkinje image identification unit 352.

The Pulkin-e image specifying unit 352 identifies the Pulkin-e image (an image region corresponding to the Pulkin-e image) by analyzing each of the two captured images. This specific process includes, for example, a threshold value process related to a pixel value for searching for a bright spot (high-luminance pixel) corresponding to a Pulkinye image, as in the conventional case. Thereby, the image area in the captured image corresponding to the Purkinje image is specified.

The Pulkinje image identification unit 352 can determine the position of a representative point in the image region corresponding to the Pulkinje image. The representative point may be, for example, the center point or the center of gravity point of the image region. In this case, the Purkinje image specifying unit 352 can obtain, for example, an approximate circle or an approximate ellipse at the periphery of the image region, and can obtain the center or the center of gravity of the approximate circle or the approximate ellipse.

(Pulkinje image position identification part 353)
The Pulkinje image position specifying unit 353 specifies the position of the Pulkinje image specified by the Pulkiner image specifying unit 352 based on the information input from the Pulkiner image specifying unit 352. The position of the Pulkinje image may include at least a position in the X direction (X coordinate value) and a position in the Y direction (Y coordinate value), and may further include a position in the Z direction (Z coordinate value).

That is, the Purkinje image specifying unit 352 identifies the Purkinje image for each of the two captured images (first captured image and second captured image) acquired by using the two front eye camera 300. Here, the two captured images are images acquired by photographing from a direction different from the optical axis of the objective lens 51. When the XY alignment is substantially aligned, the Purkinje images depicted in the two captured images are formed on the optical axis of the objective lens 51.

Since the viewing angles (angles of the objective lens 51 with respect to the optical axis) of the two anterior segment cameras 300 are known and the imaging magnification is also known, the position of the Pulkinje image in the first captured image and the position in the second captured image Based on the position of the Pulkinje image, the relative position (three-dimensional position in the real space) of the Pulkinje image formed in the anterior segment of the eye with respect to the ophthalmic apparatus 1000 (anterior segment camera 300) can be obtained.

Further, based on the relative position (displacement amount) between the pupil region and the Pulkinje image in the first captured image and the relative position (displacement amount) between the pupil region and the Pulkinje image in the second captured image, the eye to be inspected E The relative position between the pupil and the Pulkinje image formed in the anterior segment of the eye can be determined.

(Pupil center specific part 354)
The pupil center specifying portion 354 corresponds to a predetermined feature point of the anterior segment by analyzing each captured image obtained by the anterior segment camera 300 or an image corrected for distortion by the image correction unit 351. Specify the position in the captured image. In this embodiment, the pupil center of the eye E to be inspected is identified. The center of gravity of the pupil may be obtained as the center of the pupil. Further, it can be configured to specify a feature point other than the center of the pupil (center of gravity of the pupil).

The pupil center identification unit 354 identifies an image region (pupil region) corresponding to the pupil of the eye E to be inspected based on the distribution of pixel values (luminance values, etc.) of the captured image. Since the pupil is generally expressed with a lower brightness than other parts, the pupil region can be specified by searching the low-brightness image region. At this time, the pupil region may be specified in consideration of the shape of the pupil. That is, it can be configured to specify the pupil region by searching for a substantially circular and low-luminance image region.

Next, the pupil center specifying portion 354 specifies the center position of the specified pupil region. Since the pupil is substantially circular as described above, the contour of the pupil region can be specified, the center position of the approximate ellipse of this contour can be specified, and this can be used as the center of the pupil. Further, the center of gravity of the pupil region may be obtained, and the position of the center of gravity may be set as the center of the pupil.

Even when other feature points are applied, it is possible to specify the position of the feature points based on the distribution of the pixel values of the captured image in the same manner as described above.

(Pupil center position identification part 355)
The pupil center position specifying portion 355 is based on the positions (and imaging magnifications) of the two anterior segment cameras 300 and the positions of the pupil centers in the two captured images identified by the pupil center identifying portion 354. Identify the three-dimensional position of the center of the pupil of E.

For example, as disclosed in Patent Document 1 (Japanese Unexamined Patent Publication No. 2013-248376), the distance (baseline length) between the two front eye cameras 300 is set to "B", and the two front eye cameras 300. Let "H" be the distance (shooting distance) between the baseline of the eye and the center of the pupil of the eye E to be inspected, and let "f" be the distance (screen distance) between each anterior segment camera 300 and its screen plane. .. Assuming that the pixel resolution is Δp, the resolution of the image captured by the anterior segment camera 300 is expressed by the following equation.

Resolution in the xy direction (planar resolution): Δxy = H × Δp / f
Resolution in the z direction (depth resolution): Δz = H × H × Δp / (B × f)

The pupil center position specifying unit 355 uses a known trigonometry in consideration of the positional relationship with respect to the positions (known) of the two anterior segment cameras 300 and the positions corresponding to the pupil centers in the two captured images. By applying, the three-dimensional position of the center of the pupil as a feature site is calculated.

(Movement target position determination unit 356)
The movement target position determination unit 356 determines the movement target position of the device optical system based on the position of the Pulkiner image specified by the Pulkinje image position identification unit 353 and the pupil center position specified by the pupil center position identification unit 355. decide. For example, the movement target position determination unit 356 obtains the difference between the specified position of the Purkinje image and the specified pupil center position, and determines the movement target position so that the obtained difference satisfies the predetermined alignment completion condition. To do.

The main control unit 211 controls the movement mechanism 200 based on the movement target position determined by the movement target position determination unit 356.

(Tracking processing unit 360)
As shown in FIG. 7, the tracking processing unit 360 includes an eyeball model generation unit 361 and an analysis unit 362. The eyeball model generation unit 361 includes a parameter calculation unit 361A and a model generation unit 361B. The analysis unit 362 includes a corneal incident position specifying unit 362A, a rotation angle calculating unit 362B, a retinal incident position specifying unit 362C, and a scanning processing unit 362D.

(Eyeball model generation unit 361)
The eye model generation unit 361 creates a three-dimensional eye model of the eye to be inspected E based on the intraocular parameter 212A. The eyeball model generation unit 361 can obtain parameters that can be calculated based on the results of kerato measurement, eye refractive power measurement (ref measurement), or OCT measurement among the parameters included in the above-mentioned intraocular parameter 212A. is there.

The eye model generation unit 361 can obtain the above-mentioned size parameter, shape parameter, and optical parameter.

As mentioned above, the size parameter represents the size of part or all of the eye. Size parameters that represent part of the eye include corneal thickness, crystalline lens thickness, anterior chamber depth (distance between the posterior surface of the cornea and the anterior surface of the crystalline lens), retinal thickness, and pupil diameter. As a size parameter representing the entire eye, for example, there is an axial length.

As described above, the shape parameters represent the shape of the part of the eye. The site of the eye may be, for example, anterior cornea, posterior cornea, anterior lens, posterior lens, retinal surface, predetermined layer of retina, choroid, pupil (iris) and the like. Further, the parameters representing the shape include a curvature at a predetermined point, a curvature distribution in a predetermined range, an inclination angle, and the like.

As mentioned above, the optical parameters represent the optical function of the part of the eye. Optical parameters include the refractive power of the cornea (front and rear surfaces) (spherical degree, astigmatic degree, astigmatic axis, etc.) and the refractive power of the crystalline lens (front and rear surfaces). Further, the optical parameters may include arbitrary parameters related to aberrations such as chromatic aberration, spherical aberration, coma, astigmatism, curvature of field, and distortion. Further, the optical parameters may include arbitrary parameters related to the optical characteristics of the eye portion, such as the refractive index, reflectance, dispersion characteristics, and polarization characteristics of the eye portion.

In addition, based on the data obtained by the kerato measurement, the optical power measurement, or the OCT measurement, the parameter included in the intraocular parameter 212A may be corrected and applied as a new parameter constituting the eyeball model.

(Parameter calculation unit 361A)
The parameter calculation unit 361A obtains the parameters related to the eye E to be inspected by analyzing the OCT data (data set) obtained by the OCT optical system 8. The OCT dataset represents the morphology of the three-dimensional region of eye E to be inspected, including the area from the anterior surface of the cornea to the surface of the retina. That is, this three-dimensional region corresponds to the measurement region by OCT, and the image obtained as the OCT data set depicts the morphology of each part of the eye E to be inspected in this three-dimensional region.

For example, the parameter calculation unit 361A, as the intraocular distance calculation unit, obtains one or more intraocular distances in the eye E to be inspected based on the detection result of the interference light LC obtained by the OCT optical system 8. The intraocular distance of 1 or more includes the axial length (distance from the apex of the cornea to the inner limiting membrane), the corneal thickness, the depth of the anterior chamber, the lens thickness, the vitreous cavity length, the retina thickness, the choroidal thickness, and the like.

FIG. 8 shows an explanatory diagram of parameters according to the embodiment. FIG. 8 schematically shows the cross-sectional structure of the eyeball.

For example, as shown in FIG. 8, the parameters include the refractive index of each part in the eye, the intraocular distance as a size parameter, and the radius of curvature as a shape parameter. The refractive index includes the refractive index n1 of the cornea, the refractive index n2 of the aqueous body (Aqueos human), the refractive index n3 of the crystalline lens (Crystalline lens), and the refractive index n4 of the vitreous body (Vitreous body). The intraocular distance includes Central Cornea Stickness CCT, Anterior Chamber Depth ACD corresponding to the distance from the back surface of the cornea to the front surface of the crystalline lens, Lens Stickness LT, and Vitreous thickness. Chamber Depth) VCD and the like. Radius of curvature includes Radius of curvature of the antenna of the radius of curvature R1, Radius of curvature of curve of the radius of curvature of the lens, and front of the radius of curvature of the lens. Surface of lenses R3, Radius of curvature of the posterior surface of lens R4 and the like.

As the above-mentioned refractive index, a parameter of an eyeball model such as a known model eye (intraocular parameter 212A) can be used. The parameter calculation unit 361A can calculate at least one of the above size parameters and shape parameters.

An example of the process of calculating the size parameter from the OCT data set will be described. First, the parameter calculation unit 361A specifies the site of the target eye E to be inspected. This process is performed by analyzing the pixel values of the OCT dataset and includes known image processing such as filter processing, threshold processing, edge detection and the like. As a typical example, the anterior surface of the cornea and the posterior surface of the cornea are specified when determining the corneal thickness, the anterior surface of the lens and the posterior surface of the lens are specified when determining the thickness of the crystalline lens, and the posterior surface of the cornea is specified when determining the depth of the anterior chamber. And the anterior surface of the crystalline lens are specified, the front surface of the retina and the back surface of the retina are specified when the network thickness is obtained, and the edge of the iris (border of the pupil) is specified when the pupil diameter is obtained. When determining the axial length from the OCT data set, the anterior surface of the cornea and the surface of the retina (a predetermined layered tissue in the retina) are specified.

Next, the parameter calculation unit 361A identifies two or more feature points that are size measurement positions among the specified parts. This processing is executed by analyzing the pixel position and / or pixel value of the specified part, and is known as, for example, pattern matching, differential calculation (curvature calculation), filter processing, threshold processing, edge detection, and the like. including. When determining the corneal thickness, the apex of the anterior surface of the cornea (apex of the cornea) and the apex of the posterior surface of the cornea are specified. The apex of the anterior surface of the cornea is specified, for example, by shape analysis of the anterior surface of the cornea, or by the Z coordinate value of the pixel of the anterior surface of the cornea. The apex of the posterior surface of the cornea is specified, for example, as the intersection of a straight line passing through the apex of the cornea and extending in the Z direction and the posterior surface of the cornea, and is specified by shape analysis of the posterior surface of the cornea or by the Z coordinate value of the pixel of the posterior surface of the cornea. To. The same processing is executed for other parameters.

Further, the parameter calculation unit 361A obtains the size based on the specified two or more feature points. When determining the corneal thickness, the distance between the identified apex of the anterior surface of the cornea and the apex of the posterior surface of the cornea is determined. This distance may be expressed by, for example, the number of pixels between two vertices, or may be a value obtained by converting this number of pixels into a real space distance based on the shooting magnification. Such conversion processing to the real space distance can be performed by, for example, the method disclosed in Japanese Patent Application Laid-Open No. 2016-43155.

An example of the process of calculating the shape parameter from the OCT data set will be described. First, the parameter calculation unit 361A specifies the site of the target eye E to be inspected. This process may be similar to that for size parameters. Next, the parameter calculation unit 361A calculates the shape parameter based on the specified portion. For example, when obtaining the curvature at a feature point, the feature point can be specified in the same manner as the size parameter, and the curvature at this feature point can be calculated based on the shape in the vicinity of the feature point. When obtaining the curvature distribution in a predetermined range, the same processing may be performed for each point in the range. When determining the tilt angle, it is possible to perform differential processing based on the shape of the position (point) and its vicinity.

An example of the process of calculating the optical parameters from the OCT data set will be described. The OCT data set represents the morphology (shape, size, etc.) of the part of the eye E to be inspected. For the optical parameters that can be calculated only from the shape of the part, it is possible to calculate the optical parameters by using a known mathematical formula that associates the shape or size of the part with the optical parameters. Further, for optical parameters that cannot be calculated only from the morphology of the part, it is possible to use a known mathematical formula while referring to other necessary values (measured values or standard values such as model eye data). is there. For example, when determining the refractive power of the crystalline lens, the refractive index of the crystalline lens and the refractive index of a portion adjacent thereto can be referred to. It is also possible to obtain the refractive power by performing ray tracing assuming paraxial approximation.

Further, the parameter calculated by the parameter calculation unit 361A or the intraocular parameter 212A includes the central position of the rotation of the eye (or the eye to be inspected E), the corneal GRIN (gradient index) structure (refractive index distribution structure), and the crystalline lens GRIN structure (refractive index distribution structure). Refraction rate distribution structure), curvature of the fundus (retina), refraction wavelength dispersion, etc. may be included. The refractive index wavelength dispersion may include the respective refractive index wavelength dispersions of the cornea, aqueous humor, lens, and vitreous.

(Model generation unit 361B)
The model generation unit 361B creates a three-dimensional eyeball model of the eye E to be inspected using the parameters calculated by the parameter calculation unit 361A. The model generation unit 361B can create a three-dimensional eyeball model of the eye to be inspected E by using at least one of the intraocular parameter 212A, the refractive index of the eye, the corneal shape information, and the intraocular distance.

The model generation unit 361B associates each of the parameters calculated in each of the above units with the corresponding portion in the eyeball model. This process is executed, for example, by associating a parameter with a part or feature point specified in the process of calculating the parameter. For example, parameters representing the shape of the anterior surface of the cornea (curvature, curvature distribution, etc.) are associated with the anterior surface of the cornea in the eye model. In addition, the parameter representing the axial length is associated with the anterior surface of the cornea (apical cornea, etc.) and the surface of the retina (fovea centralis, etc.) in the eyeball model. The same applies to other parameters.

(Analysis unit 362)
In addition to the above analysis process, the analysis unit 362 performs a process for identifying (estimating) the incident position of the measurement light LS in a site in the eye (for example, the cornea and the retina).

FIG. 9 shows an operation explanatory diagram of the analysis unit 362 according to the embodiment. FIG. 9 schematically shows the cross-sectional structure of the eye E to be inspected.

In the above alignment process, the main control unit 211 controls the movement mechanism 200 based on the movement target position determined by the movement target position determination unit 356. As a result, the intersection of the measurement optical axis (scan center) and the cornea Cr can be specified as the corneal incident position Pc of the measurement light LS from the anterior segment image of the eye E to be inspected. The corneal incident position Pc is a position where the measurement light LS is incident on the anterior surface of the cornea (in some embodiments, the posterior surface of the cornea). Further, the measurement light LS incident on the corneal incident position Pc is subjected to light tracing processing using the eyeball model generated by the eyeball model generation unit 361 while considering the rotation angle of the eye E to be inspected, thereby performing the measurement light. It is possible to identify the retinal incident position Pr where the LS is incident on the retina.

That is, the analysis unit 362 identifies the corneal incident position where the measurement light LS is incident on the cornea Cr and the rotation angle around the rotation point of the eye E to be inspected from the image of the anterior segment of the eye E to be inspected, and the identified cornea. Corresponding to the incident position, the retinal incident position where the measurement light LS is incident is specified in the retina. The analysis unit 362 can identify the retinal incident position by performing a known ray tracing process on the measurement light LS incident on the corneal incident position.

(Corneal incident position identification part 362A)
The corneal incident position specifying portion 362A identifies the incident position of the measurement light LS on the cornea Cr from the anterior segment image of the eye E to be inspected. When the optical system is aligned with the eye E to be inspected based on the image of the anterior segment of the eye, the corneal incident position specifying unit 362A can specify the corneal incident position using the alignment information. For example, the corneal incident position specifying unit 362A can specify the intersection of the optical axis of the device optical system and the corneal Cr of the eye E to be inspected as the corneal incident position. The anterior segment image may be any one of two or more captured images acquired by the anterior segment camera 300.

In this embodiment, the corneal incident position specifying unit 362A is the measurement light LS from the three-dimensional position of the Purkiner image identified by the Purkinje image position specifying unit 353 from two or more captured images acquired by the anterior segment camera 300. Identify the corneal incident position.

(Rotation angle calculation unit 362B)
The rotation angle calculation unit 362B calculates the rotation angle of the eye E to be inspected centering on the rotation point of the eye E to be inspected from the displacement of the characteristic portion drawn on the image of the anterior segment of the eye E to be inspected. The rotation angle calculation unit 362B can calculate at least one rotation angle in the horizontal plane and the vertical plane. The rotation angle calculation unit 362B can calculate the rotation angles in two planes that intersect each other.

10 and 11 show an operation explanatory view of the rotation angle calculation unit 362 according to the embodiment. FIG. 10 shows an intraocular parameter used for calculating the rotation angle of the eye E to be inspected in the horizontal plane. FIG. 11 shows an explanatory diagram of the calculation process of the rotation angle θ in the horizontal plane.

Rotation angle calculation unit 362B includes the corneal radius of curvature R, the center corneal thickness CCT, anterior chamber depth ACD, using the distance L _CR between the corneal vertex, rotation point, rotation angle θ around the rotation point P _R of the eye E Is calculated. The anterior chamber depth generally represents the distance from the posterior surface of the cornea to the anterior surface of the crystalline lens, but in FIG. 10, for convenience, it is the distance from the posterior surface of the cornea to the pupil (iris).

When the alignment is complete, the device optical axis is positioned approximately orthogonal to the anterior surface of the cornea. When the eye E to be inspected is rotated, when the anterior segment is viewed from the front, the displacement ΔXpur in the X direction of the Pulkinje image is the equation, assuming that the intersection of the optical axis O1 of the device and the cornea is the reference (origin of the XZ coordinate system). It is expressed as (1).

Similarly, the displacement ΔZpur of the Purkinje image in the Z direction is expressed by Eq. (2).

That is, even when the eye E to be inspected rotates, the displacement of the position of the Purkinje image does not depend on the rotation angle θ.

On the other hand, the displacement of the characteristic portion of the anterior segment of the eye E to be inspected depends on the rotation angle θ. Characteristic parts include the pupil (region), the center of the pupil, the center of gravity of the pupil, and the iris. Hereinafter, the case where the characteristic site is the center of the pupil will be described, but the same applies even if the characteristic site is another site.

When the eye E to be inspected is rotated, when the anterior segment is viewed from the front, the displacement ΔXpupil in the X direction of the center of the pupil is expressed by the equation, assuming that the intersection of the optical axis O1 of the device and the cornea is the reference (origin of the XZ coordinate system). It is expressed as in the formula (5) using the formula (3) and the formula (4).

In the formula (4) and (5), the distance _{L P-CR} represents the distance from the lens front surface to the rotation point _{P R.}

Similarly, the displacement ΔZpupil in the Z direction of the center of the pupil is expressed by the equation (8) using the equations (6) and (7).

In the formulas (5) and (8), the corneal radius of curvature R is obtained by using the Z coordinate value of the Purkinje image specified by the Purkinje image position specifying unit 353. In some embodiments, the corneal radius of curvature R is determined by the corneal shape calculation unit 222 based on the measurement results obtained by the kerato measurement system 3. The center corneal thickness CCT, anterior chamber depth ACD, and corneal distance between the vertices, rotation point _{L CR} is stored in advance as intraocular parameter 212A. Therefore, the rotation angle calculation unit 362B can calculate the rotation angle θ in the horizontal plane of the eye E to be inspected by using the equation (5) or the equation (8).

In FIG. 11, the case of calculating the rotation angle θ in the XZ plane (horizontal plane) has been described, but the same applies to the YZ plane (vertical plane). Therefore, the rotation angle calculation unit 362B can calculate the rotation angle in the vertical plane of the eye E to be inspected in the same manner as described above.

(Retina incident position specifying part 362C)
The retina incident position specifying unit 362C is an incident angle corresponding to the rotation angle calculated by the rotation angle calculation unit 362B, and the measurement light LS incident on the corneal incident position specified by the corneal incident position specifying unit 362A is incident on the retina. Identify the location. The incident angle of the measurement light LS in the cornea Cr may be the rotation angle calculated by the rotation angle calculation unit 362B. For example, the retinal incident position specifying unit 362C identifies the retinal incident position by performing a known light ray tracing process on the measurement light LS incident on the corneal incident position at an incident angle corresponding to the rotation angle of the eye E to be inspected. In the ray tracing process, the eyeball model generated by the eyeball model generator 361 is used to derive from Snell's law from the incident position of the cornea incident at the calculated incident angle to the anterior surface of the cornea, the posterior surface of the cornea, the anterior surface of the crystalline lens, and the posterior surface of the crystalline lens. By sequentially applying the known relational expressions to be obtained, the incident position of the light beam on the retina is specified.

(Scan processing unit 362D)
The scan processing unit 362D generates control information that feeds back to the optical scanner 88 so that a predetermined position of the retina becomes the scan center based on the retina incident position specified by the retina incident position specifying unit 362C. The control information includes at least one of the scan width, scan speed, and offset value of the scan center of the galvano scanner constituting the optical scanner 88. The predetermined position of the retina includes a reference position, a retinal incident position, a position between the reference position and the retinal incident position, a lesion site, a characteristic site, a blood vessel, a position specified by the user, and the like.

The main control unit 211 controls the deflection operation of the optical scanner 88 by controlling the optical scanner 88 based on the feedback control information. Tracking control becomes possible by repeating the above feedback control for each one or a plurality of OCT scans. For example, the main control unit 211 sets the scan start position in synchronization with the scan start trigger for each one or a plurality of line scans (B scans) so that a predetermined observation site (for example, the fovea centralis) can be observed. Update by feedback control. Alternatively, for example, the main control unit 211 updates the scan start position by feedback control in synchronization with the B scan start trigger so that the center of the C scan image during the 3D scan is at the same position.

For example, the scan processing unit 362D repeats the ray tracing simulation (ray tracing process) until the retina incident position converges to a predetermined position on the retina while changing the incident angle of the measurement light LS in the cornea Cr by a minute angle. The scan processing unit 362D generates control information for the optical scanner 88 so that the incident angle when the retina incident position converges to a predetermined position on the retina becomes the scan center angle. In some embodiments, the ray tracing simulation uses an eye model to which parameters representing the optical properties of the eye E to be inspected are applied.

For example, the scan processing unit 362D identifies the amount of change in the incident angle of the measured light LS in the cornea Cr from table information or a predetermined function based on the displacement of the incident position of the retina as the reference position in the retina, and the specified change. Control information for the optical scanner 88 is generated based on the quantity. In some embodiments, the change in the incident angle of the measurement light LS is specified according to table information or a function with a parameter representing the optical characteristics of the eye E to be inspected as a variable.

The data processing unit 225 having the above configuration includes, for example, a processor, RAM, ROM, hard disk drive, and the like. A computer program that causes a processor to execute the above-mentioned processing is stored in a storage device such as a hard disk drive in advance.

(Display unit 270, operation unit 280)
As a user interface unit, the display unit 270 displays information under the control of the control unit 210. The display unit 270 includes the display unit 10 shown in FIG. 1 and the like.

The operation unit 280 is used as a user interface unit to operate the ophthalmic apparatus. The operation unit 280 includes various hardware keys (joysticks, buttons, switches, etc.) provided in the ophthalmic apparatus. Further, the operation unit 280 may include various software keys (buttons, icons, menus, etc.) displayed on the touch panel type display screen 10a.

At least a part of the display unit 270 and the operation unit 280 may be integrally configured. A typical example thereof is a touch panel type display screen 10a.

(Communication unit 290)
The communication unit 290 has a function for communicating with an external device (not shown). The communication unit 290 includes a communication interface according to the connection form with the external device. An example of an external device is a spectacle lens measuring device for measuring the optical characteristics of a lens. The spectacle lens measuring device measures the power of the spectacle lens worn by the subject, and inputs this measurement data to the ophthalmic device 1000. Further, the external device may be an arbitrary ophthalmic device, a device (reader) for reading information from a recording medium, a device (writer) for writing information on a recording medium, or the like. Further, the external device may be a hospital information system (HIS) server, a DICOM (Digital Imaging and Communication in Medicine) server, a doctor terminal, a mobile terminal, a personal terminal, a cloud server, or the like. The communication unit 290 may be provided in, for example, the processing unit 9.

The OCT optical system 8 is an example of the “optical system” according to the embodiment. The anterior segment camera 300 is an example of the “acquisition unit” and the “photographing unit” according to the embodiment. The alignment light projection system 2 is an example of the "alignment optical system" according to the embodiment. The kerato measurement system 3 is an example of the “corneal shape measurement optical system” according to the embodiment. The reflex measurement projection system 6 and the reflex measurement light receiving system 7 are examples of the “refractive power measurement optical system” according to the embodiment. The eye refractive power calculation unit 221 is an example of the “refractive power value calculation unit” according to the embodiment. The kerato measurement system 3 is an example of the “corneal shape measurement optical system” according to the embodiment. The reflex measurement optical system (refraction measurement projection system 6 and reflex measurement light receiving system 7) is an example of the “refractive power measurement optical system” according to the embodiment. The eye refractive power calculation unit 221 is an example of the “refractive power value calculation unit” according to the embodiment. The parameter calculation unit 361A is an example of the “intraocular distance calculation unit” according to the embodiment.

<Operation example>
The operation of the ophthalmic apparatus 1000 according to the embodiment will be described.

(First operation example)
FIG. 12 shows an example of the first operation of the ophthalmic apparatus 1000. FIG. 12 shows a flow chart of an operation example of the ophthalmic apparatus 1000. A computer program for realizing the process shown in FIG. 12 is stored in the storage unit 212. The main control unit 211 executes the process shown in FIG. 12 by operating according to this computer program.

(S1: Acquire corneal shape parameters, ocular refractive power, and axial length)
First, the ophthalmic apparatus 1000 acquires the corneal shape parameter of the eye to be inspected E, the refractive power of the eye to be inspected E, and the axial length. The corneal shape parameters and the like are acquired from an external ophthalmic device or an external device such as an electronic medical record system.

In some embodiments, after the alignment of the optical system with respect to the eye E to be inspected is completed, the corneal shape parameters and the like are acquired by the measurement with respect to the eye E to be inspected. The corneal shape parameters are obtained by performing a kerato measurement on the eye E to be inspected. The refractive power of the eye is obtained by performing a ref measurement on the eye E to be inspected. The axial length is obtained, for example, by performing an OCT measurement on the eye E to be inspected. Hereinafter, the case where the axial length is acquired as the intraocular parameter will be described, but the intraocular parameter other than the axial length may be acquired.

When performing kerato measurement, the main control unit 211 causes the liquid crystal panel 41 to display a pattern indicating the fixation target at a display position corresponding to a desired fixation position. As a result, the eye E to be inspected is gazed at a desired fixation position. After that, the main control unit 211 turns on the keratling light source 32. When light is output from the keratling light source 32, a ring-shaped luminous flux for measuring the shape of the cornea is projected onto the cornea Cr of the eye E to be inspected. The corneal shape calculation unit 222 calculates the corneal radius of curvature by performing arithmetic processing on the image acquired by the image pickup element 59, and the corneal refractive power, corneal astigmatism, and corneal astigmatism axis are calculated from the calculated corneal radius of curvature. Calculate the angle. In the control unit 210, the calculated corneal refractive power and the like are stored in the storage unit 212.

When performing the refraction measurement, the main control unit 211 projects a ring-shaped measurement pattern luminous flux for measuring the refractive power onto the eye E to be inspected as described above. A ring image based on the return light of the measurement pattern luminous flux from the eye E to be inspected is formed on the image pickup surface of the image pickup device 59. The main control unit 211 determines whether or not a ring image based on the return light from the fundus Ef detected by the image sensor 59 could be acquired. For example, the main control unit 211 detects the position (pixel) of the edge of the image based on the return light detected by the image sensor 59, and whether the width of the image (difference between the outer diameter and the inner diameter) is equal to or more than a predetermined value. Judge whether or not. Alternatively, the main control unit 211 determines whether or not a ring image can be obtained by determining whether or not a ring can be formed based on a point (image) having a predetermined height (ring diameter) or more. May be good.

When it is determined that the ring image can be acquired, the eye refractive power calculation unit 221 analyzes the ring image based on the return light of the measurement pattern luminous flux projected on the eye E to be inspected by a known method, and analyzes the temporary spherical power S and the temporary spherical power S. A tentative astigmatic power C is obtained. Based on the obtained temporary spherical power S and astigmatic power C, the main control unit 211 sets the ref measurement light source 61, the focusing lens 74, and the fixation unit 40 (liquid crystal panel 41) to the equivalent spherical power (S + C / 2). Move to the position of (the position corresponding to the temporary far point). The main control unit 211 further moves the fixation unit 40 (liquid crystal panel 41) from that position to the cloud fog position, and then controls the reflex measurement projection system 6 and the reflex measurement light receiving system 7 as the main measurement to obtain a ring image. Get it again. The main control unit 211 causes the ocular refractive power calculation unit 221 to calculate the spherical power, the astigmatism power, and the astigmatism axis angle from the analysis result of the ring image obtained in the same manner as described above and the movement amount of the focusing lens 74.

Further, the eye refractive power calculation unit 221 obtains a position corresponding to the far point of the eye E to be inspected (a position corresponding to the far point obtained by this measurement) from the obtained spherical power and astigmatic power. The main control unit 211 moves the liquid crystal panel 41 to a position corresponding to the obtained far point. In the control unit 210, the position of the focusing lens 74, the calculated spherical power, and the like are stored in the storage unit 212.

When it is determined that the ring image cannot be acquired, the main control unit 211 considers the possibility of an abnormally intense refraction eye and sets the ref measurement light source 61 and the focusing lens 74 on the minus power side (for example, in a preset step). -10D), move to the plus frequency side (for example, + 10D). The main control unit 211 detects the ring image at each position by controlling the ref measurement light receiving system 7. When it is determined that the ring image cannot be acquired even after that, the main control unit 211 executes a predetermined measurement error process. At this time, the operation of the ophthalmic apparatus 1000 may shift to the next step. In the control unit 210, information indicating that the reflex measurement result was not obtained is stored in the storage unit 212.

When performing OCT measurement, the main control unit 211 moves the fixation unit 40 (liquid crystal panel 41) from the cloud fog position to the in-focus position. In some embodiments, the in-focus position maximizes the intensity of the interference signal or the like from the position of the equivalent spherical power (S + C / 2) specified in step S3 or the position of the equivalent spherical power (S + C / 2). It is the position where the focus is adjusted.

Subsequently, the main control unit 211 turns on the OCT light source 101 and controls the optical scanner 88 to scan a predetermined portion of the fundus Ef (for example, a portion including the macula) with the measurement light LS.

The main control unit 211 causes the parameter calculation unit 361A to calculate the axial length of the eye to be inspected E. The parameter calculation unit 361A identifies a position corresponding to the corneal apex and a position corresponding to the fundus from the peak position of the acquired interference light LC detection signal, and calculates the axial length from the specified position. The parameter calculation unit 361A may calculate the above parameters other than the axial length.

(S2: Generate eyeball model)
Subsequently, the main control unit 211 generates a three-dimensional eyeball model of the eye to be inspected E using the corneal shape parameter, the refractive index of the eye, and the axial length calculated by the parameter calculation unit 361A acquired in step S1. It is generated in the part 361B.

(S3: OCT measurement?)
The main control unit 211 determines whether or not to execute the OCT measurement. For example, the main control unit 211 determines whether or not to execute the OCT measurement based on the operation content of the operation unit 280 by the user or the operation mode set in advance.

When it is determined to execute the OCT measurement (S3: Y), the operation of the ophthalmic apparatus 1000 shifts to step S4. When it is determined that the OCT measurement is not performed (S3: N), the operation of the ophthalmic apparatus 1000 is completed (end).

(S4: Within the default range?)
When it is determined in step S3 that the OCT measurement is to be executed (S3: Y), the main control unit 211 executes the above alignment process.

In the alignment process, the main control unit 211 turns on the alignment light source 21. Further, the main control unit 211 controls the anterior segment camera 300 to photograph the anterior segment of the eye E to be inspected, which is irradiated with the alignment light output from the alignment light source 21, substantially simultaneously. In the main control unit 211, whether or not the displacement between the position of the device optical system acquired by the optical system position acquisition unit 213 and the movement target position obtained by the alignment processing unit 350 as described above is within a predetermined range. To judge.

When it is determined that the displacement between the position of the device optical system and the movement target position is within the predetermined range (S4: Y), the operation of the ophthalmologic device 1000 moves to step S6. When it is determined that the displacement between the position of the device optical system and the movement target position is not within the predetermined range (S4: N), the operation of the ophthalmologic device 1000 moves to step S5.

(S5: Relative movement)
When it is determined in step S4 that the displacement between the position of the device optical system and the movement target position is not within the predetermined range (S4: N), the main control unit 211 controls the movement mechanism 200 to examine the eye. The device optical system is moved relative to E by a predetermined step. After that, the operation of the ophthalmic apparatus 1000 shifts to step S4.

(S6: Start tracking with optical scanner)
When it is determined in step S4 that the displacement between the position of the device optical system and the movement target position is within the predetermined range (S4: Y), in the main control unit 211, the optical system shown in FIG. 1 is the eye E. It is determined that the device has been moved to the inspection position, and the reflex measurement light source 61, the focusing lens 74, and the fixation unit 40 (liquid crystal panel 41) are placed at the origin position (for example, the position corresponding to 0D) along the respective optical axes. Move to. Here, the inspection position is a position where the inspection of the eye E to be inspected can be performed within sufficient accuracy.

Subsequently, the main control unit 211 starts the tracking process by the optical scanner 88. The details of step S6 will be described later.

(S7: OCT measurement)
The main control unit 211 moves the fixation unit 40 (liquid crystal panel 41) from the cloud fog position to the focusing position. In some embodiments, the in-focus position has the maximum intensity of the interference signal from the position corresponding to the equivalent spherical power (S + C / 2) acquired in step S1 or the position of the equivalent spherical power (S + C / 2). The focus is adjusted so that

Subsequently, the main control unit 211 turns on the OCT light source 101 and controls the optical scanner 88 to scan a predetermined portion of the fundus Ef (for example, a portion including the macula) with the measurement light LS.

The main control unit 211 can send the detection signal obtained by scanning the measurement light LS to the image forming unit 224, and cause the image forming unit 224 to form a tomographic image of the fundus Ef from the obtained detection signal. Further, the main control unit 211 can display the formed tomographic image on the display unit 270. This is the end of the operation of the ophthalmic apparatus 1000 (end).

FIG. 13 shows a flow chart of an operation example of step S6 of FIG. A computer program for realizing the process shown in FIG. 13 is stored in the storage unit 212. The main control unit 211 executes the process shown in FIG. 13 by operating according to this computer program.

(S11: Specify the corneal incident position)
The main control unit 211 identifies the corneal incident position of the measurement light LS from the three-dimensional position of the corneal image identified by the Pulkiner image position specifying unit 353 based on the captured image acquired by the anterior segment camera 300. Let part 362A specify.

(S12: Calculate the rotation angle)
As shown in FIG. 11, the main control unit 211 determines the rotation angle in the horizontal plane and the rotation angle in the vertical plane from the displacement of the pupil center specified from the captured image by the intraocular parameter 212A and the pupil center position specifying unit 355. Let the rotation angle calculation unit 362B calculate.

(S13: Specify the incident position on the retina)
The main control unit 211 has an eyeball model generated by the eyeball model generation unit 361 with respect to the measurement light LS incident on the corneal incident position specified in step S11 at the incident angle corresponding to the rotation angle calculated in step S12. The retinal incident position is specified by the retinal incident position specifying unit 362C by performing a light ray tracing process using the above.

(S14: Calculate displacement)
The analysis unit 362 obtains the displacement of the incident position of the retina with respect to the reference position in the retina. The analysis unit 362 obtains at least one of the displacement in the horizontal plane and the displacement in the vertical plane. The analysis unit 362 may obtain displacements in two planes intersecting each other. The reference position may be specified by analyzing the tomographic image of the eye E to be inspected acquired by using the OCT optical system 8, or may be specified by the user using the operation unit 280. Reference positions include the fovea centralis, macula, lesions, optic disc, and blood vessels.

(S15: Optical scanner processing)
The main control unit 211 causes the scan processing unit 362D to generate control information to be fed back to the optical scanner 88 from the displacement between the reference position and the retina incident position in the retina identified in step S14. The details of step S15 will be described later.

(S16: Controls the optical scanner)
The main control unit 211 controls the deflection operation of the optical scanner 88 based on the control information generated in the optical scanner processing in step S15.

This completes the process of step S6 in FIG. 12 (end). For example, the main control unit 211 can execute the process shown in FIG. 13 for each one or a plurality of OCT scans. That is, tracking control becomes possible by repeating the above feedback control for each one or a plurality of OCT scans.

FIG. 14 shows a flow chart of an operation example of step S13 of FIG. A computer program for realizing the process shown in FIG. 14 is stored in the storage unit 212. The main control unit 211 executes the process shown in FIG. 14 by operating according to this computer program.

(S21: Obtained eyeball model)
For example, the main control unit 211 causes the retina incident position specifying unit 362C to acquire an eyeball model (an eyeball model such as a known model eye) stored in advance in the storage unit 212.

(S22: Specify the incident position on the retina)
Subsequently, the main control unit 211 causes the retina incident position specifying unit 362C to specify the retinal incident position of the measurement light LS deflected by the optical scanner 88 in the same manner as in step S13. That is, first, the corneal incident position specifying unit 362A is the three-dimensional position of the Purkiner image specified by the Purkiner image position specifying unit 353 based on the two captured images acquired by the anterior segment camera 300, as in step S11. From the above, the corneal incident position of the measurement light LS is specified. Subsequently, the rotation angle calculation unit 362B calculates the rotation angle of the eye E to be inspected based on the intraocular parameter 212A and the displacement of the center of the pupil from the captured image, as in step S12. The retinal incident position specifying unit 362C has an incident angle corresponding to the rotation angle calculated by the rotation angle calculating unit 362B, and the measurement light LS incident on the corneal incident position specified by the corneal incident position specifying unit 362A is subject to step S21. The position of incidence on the retina is specified by performing a light ray tracing process using the eyeball model obtained in.

(S23: Displacement ΔX, ΔY are calculated)
Next, the main control unit 211 analyzes the displacement of the retinal incident position with respect to the reference position on the retina (displacement ΔX in the horizontal plane (displacement in the X-axis direction), displacement ΔY in the vertical plane (displacement in the Y-axis direction)). Let 362 calculate. In FIG. 15, the displacement ΔX in the horizontal plane due to the measurement light LS deflected around the pivot point Pv, which is a position optically conjugated with the optical scanner 88, is shown, but the displacement ΔY in the vertical plane is also the same. is there. The reference position is, for example, a position corresponding to the fovea centralis identified from the tomographic image of the eye E to be inspected acquired by the OCT optical system 8. For example, by associating the position of each part in the tomographic image with the position of each part in the eyeball model in advance, it is possible to specify the position in the eyeball model corresponding to the part specified in the tomographic image. Thereby, the analysis unit 362 can specify the displacement of the retinal incident position (displacement in the X-axis direction, displacement in the Y-axis direction) with respect to the reference position.

(S24: Change the angle of incidence)
In a minute region, the amount of change in the incident angle and the displacement of the position on the retina are considered to have a linear relationship, so it is possible to estimate the amount of change in the angle of incidence from the displacement of the position on the retina. Therefore, the main control unit 211 changes the incident angle condition in the light ray tracing process so that the incident angle of the measurement light LS deflected by the optical scanner 88 in the cornea Cr is changed by a predetermined minute angle.

(S25: Specify the incident position on the retina)
The retina incident position specifying unit 362C identifies a new retina incident position by performing a light ray tracing process on the measurement light LS whose incident angle is changed in the cornea Cr in step S24 in the same manner as in step S22.

(S26: Calculate the displacements ΔX'and ΔY')
Similar to step S23, the main control unit 211 displaces the retinal incident position with respect to the reference position in the retina with respect to the retinal incident position specified in step S25 (displacement ΔX ′ in the horizontal plane, displacement ΔY ′ in the vertical plane). ) Is calculated by the analysis unit 362. In FIG. 15, the displacement ΔX ′ in the horizontal plane is shown, but the displacement ΔY ′ in the vertical plane is also the same. The reference position is the same as the reference position in step S23.

(S27: Within the threshold?)
The main control unit 211 determines whether or not each of the displacements ΔX ′ and ΔY ′ calculated in step S26 is within a predetermined threshold value. The threshold value for the displacement ΔX'and the threshold value for ΔY'may be the same value or different values.

When it is determined in step S27 that each of the displacements ΔX'and ΔY'is within a predetermined threshold value (S27: Y), the operation of the ophthalmic apparatus 1000 shifts to step S28. When it is determined in step S27 that each of the displacements ΔX'and ΔY'is not within a predetermined threshold value (S27: N), the operation of the ophthalmic apparatus 1000 shifts to step S24. That is, steps S24 to S26 are repeated until each of the displacements ΔX ′ and ΔY ′ converges within the permissible range.

(S28: Generate control information of optical scanner)
When it is determined in step S27 that each of the displacements ΔX'and ΔY'is within a predetermined threshold value (S27: Y), the main control unit 211 sets the incident angle of the measurement light LS at the time of convergence to the scan center angle. Therefore, the scan processing unit 362D is made to generate control information for changing at least one of the scan width, the scan speed, and the offset value of the scan center of the optical scanner 88. The main control unit 211 controls the optical scanner 88 based on the control information generated by the scan processing unit 362D. This makes it possible to perform tracking control so that the center of the OCT image is at a predetermined position.

This completes the process of step S15 in FIG. 13 (end).

In the process of FIG. 14, the retina incident position was specified using the eyeball model stored in advance in the storage unit 212, but the process according to the embodiment is not limited to this. For example, the retinal incident position may be specified using an eye model including an intraocular parameter representing the optical characteristics of the eye E to be inspected.

FIG. 16 shows a flow chart of an operation example of step S15 according to a modification of the first operation example. A computer program for realizing the process shown in FIG. 16 is stored in the storage unit 212. The main control unit 211 executes the process shown in FIG. 16 by operating according to this computer program.

(S31: Obtain the measured value)
Similar to step S1, the main control unit 211 causes the eyeball model generation unit 361 to acquire the corneal shape parameter of the eye to be inspected E, the refractive power of the eye to be inspected E, and the axial length. The corneal shape parameters and the like are acquired by the measurement with respect to the eye E to be inspected as described above. The corneal shape parameters are obtained by performing a kerato measurement on the eye E to be inspected. The refractive power of the eye is obtained by performing a ref measurement on the eye E to be inspected. The axial length is obtained, for example, by performing an OCT measurement on the eye E to be inspected. Intraocular parameters other than the axial length may be acquired as intraocular parameters.

(S32: Generate eyeball model)
Next, the main control unit 211 generates a three-dimensional eyeball model of the eye to be inspected E using the corneal shape parameter acquired in step S31, the refractive error of the eye, and the axial length calculated by the parameter calculation unit 361A. It is generated in the part 361B.

(S33: Specify the incident position on the retina)
Subsequently, the main control unit 211 causes the retina incident position specifying unit 362C to specify the retinal incident position of the measurement light LS deflected by the optical scanner 88 in the same manner as in step S22.

(S34: Displacement ΔX, ΔY are calculated)
Next, the main control unit 211 causes the analysis unit 362 to calculate the displacement of the retinal incident position (displacement ΔX in the horizontal plane, displacement ΔY in the vertical plane) with respect to the reference position in the retina, as in step S23.

(S35: Change the angle of incidence)
Next, the main control unit 211 changes the incident angle condition in the ray tracing process so that the incident angle of the measurement light LS deflected by the optical scanner 88 in the cornea Cr is changed by a predetermined minute angle, as in step S24. To do.

(S36: Specify the incident position on the retina)
Next, the retinal incident position specifying unit 362C identifies a new retinal incident position by performing a ray tracing process on the measurement light LS whose incident angle has been changed in the cornea Cr in step S35, as in step S25. ..

(S37: Displacement ΔX', ΔY'calculated)
Similar to step S26, the main control unit 211 displaces the retinal incident position with respect to the reference position in the retina with respect to the retinal incident position specified in step S36 (displacement ΔX ′ in the horizontal plane, displacement ΔY ′ in the vertical plane). ) Is calculated by the analysis unit 362.

(S38: Within the threshold?)
Similar to step S27, the main control unit 211 determines whether or not each of the displacements ΔX ′ and ΔY ′ calculated in step S37 is within a predetermined threshold value.

When it is determined in step S38 that each of the displacements ΔX'and ΔY'is within a predetermined threshold value (S38: Y), the operation of the ophthalmic apparatus 1000 shifts to step S39. When it is determined in step S38 that each of the displacements ΔX'and ΔY'is not within a predetermined threshold value (S38: N), the operation of the ophthalmic apparatus 1000 shifts to step S35.

(S39: Generate control information for optical scanner)
When it is determined in step S38 that each of the displacements ΔX'and ΔY'is within a predetermined threshold value (S38: Y), the main control unit 211 receives the measurement light LS when it converges, as in step S28. The scan processing unit 362D is made to generate control information for changing at least one of the scan width, the scan speed, and the offset value of the scan center of the optical scanner 88 so that the angle becomes the scan center angle. The main control unit 211 controls the optical scanner 88 based on the control information generated by the scan processing unit 362D.

This completes the process of step S15 according to the modified example of the first operation example (end).

(Second operation example)
Next, a second operation example of the ophthalmic apparatus 1000 according to the embodiment will be described. The difference between the second operation example and the first operation example is mainly that the control information for controlling the optical scanner 88 according to the table information or a predetermined function without repeating the ray tracing process until the above displacement converges. Is the point to generate.

Also in the second operation example, the same processing as that shown in FIGS. 12 and 13 is executed.

FIG. 17 shows a flow chart of an operation example of step S15 of FIG. 13 according to the second operation example. A computer program for realizing the process shown in FIG. 17 is stored in the storage unit 212. The main control unit 211 executes the process shown in FIG. 17 by operating according to this computer program.

(S41: Obtained eyeball model)
Similar to step S21, the main control unit 211 causes the retina incident position specifying unit 362C to acquire an eyeball model (an eyeball model such as a known model eye) stored in advance in the storage unit 212.

(S42: Specify the incident position on the retina)
Subsequently, the main control unit 211 causes the retina incident position specifying unit 362C to specify the retinal incident position of the measurement light LS deflected by the optical scanner 88 in the same manner as in step S22.

(S43: Displacement ΔX, ΔY are calculated)
Next, the main control unit 211 causes the analysis unit 362 to calculate the displacement of the retinal incident position (displacement ΔX in the horizontal plane, displacement ΔY in the vertical plane) with respect to the reference position in the retina, as in step S23. In FIG. 18, the displacement ΔX in the horizontal plane due to the measurement light LS deflected around the pivot point Pv, which is a position optically conjugated with the optical scanner 88, is shown, but the displacement ΔY in the vertical plane is also the same. is there. The reference position is, for example, a position corresponding to the fovea centralis identified from the tomographic image of the eye E to be inspected acquired by the OCT optical system 8. For example, by associating the position of each part in the tomographic image with the position of each part in the eyeball model in advance, it is possible to specify the position in the eyeball model corresponding to the part specified in the tomographic image. Thereby, the analysis unit 362 can specify the displacement of the retinal incident position (displacement in the X-axis direction, displacement in the Y-axis direction) with respect to the reference position.

(S44: Specify the amount of change in the incident angle)
In this example, table information is stored in advance in the storage unit 212. The table information is associated with the amount of change in the incident angle of the measurement light LS (the amount of change in the deflection angle of the optical scanner 88) corresponding to the above displacements ΔX and ΔY. Such table information is obtained in advance by calculation using the above-mentioned eyeball model. The main control unit 211 causes the scan processing unit 362D to specify the amount of change in the incident angle of the measurement light LS corresponding to the displacements ΔX and ΔY calculated in step S43 with reference to the table information.

In step S44, the amount of change in the incident angle is specified with reference to the table information, but the amount of change in the incident angle may be specified according to a predetermined function. The predetermined function is represented by, for example, a first-order or second-order polynomial (may be a polynomial of third-order or higher) having displacements ΔX and ΔY as variables.

(S45: Generate control information of optical scanner)
Based on the amount of change in the incident angle identified in step S44, the main control unit 211 sets at least one of the scan width, scan speed, and offset value of the scan center of the optical scanner 88 so that the predetermined position becomes the scan center. The scan processing unit 362D is made to generate control information for changing one. For example, the main control unit 211 generates control information so that the incident angle reflecting the specified change amount of the incident angle becomes the scan center angle. The main control unit 211 controls the optical scanner 88 based on the generated control information.

This completes the process of step S15 in FIG. 13 (end).

In this example, since it is executed every time the OCT scan is performed, the change in the displacement of the center position of the retina with respect to the reference position gradually converges.

In the process of FIG. 17, the retina incident position was specified using the eyeball model stored in advance in the storage unit 212, but the process according to the embodiment is not limited to this. For example, the retinal incident position may be specified using an eye model including an intraocular parameter representing the optical characteristics of the eye E to be inspected.

FIG. 19 shows a flow chart of an operation example of step S15 according to a modification of the second operation example. A computer program for realizing the process shown in FIG. 19 is stored in the storage unit 212. The main control unit 211 executes the process shown in FIG. 19 by operating according to this computer program.

(S51: Obtain the measured value)
Similar to step S31, the main control unit 211 causes the eyeball model generation unit 361 to acquire the corneal shape parameter of the eye to be inspected E, the refractive power of the eye to be inspected E, and the axial length. The corneal shape parameters and the like are acquired by the measurement with respect to the eye E to be inspected as described above. The corneal shape parameters are obtained by performing a kerato measurement on the eye E to be inspected. The refractive power of the eye is obtained by performing a ref measurement on the eye E to be inspected. The axial length is obtained, for example, by performing an OCT measurement on the eye E to be inspected. Intraocular parameters other than the axial length may be acquired as intraocular parameters.

(S52: Generate eyeball model)
Next, the main control unit 211 uses the corneal shape parameter acquired in step S31, the refractive error of the eye, and the axial length calculated by the parameter calculation unit 361A in the same manner as in step S32 to make the eye E to be inspected three-dimensional. Is generated by the model generation unit 361B.

(S53: Specify the incident position on the retina)
Subsequently, the main control unit 211 causes the retina incident position specifying unit 362C to specify the retinal incident position of the measurement light LS deflected by the optical scanner 88 in the same manner as in step S42.

(S54: Displacement ΔX, ΔY are calculated)
Next, the main control unit 211 causes the analysis unit 362 to calculate the displacement of the retinal incident position (displacement ΔX in the horizontal plane, displacement ΔY in the vertical plane) with respect to the reference position in the retina, as in step S43.

(S55: Specify the amount of change in the incident angle)
Similar to step S44, the main control unit 211 causes the scan processing unit 362D to specify the amount of change in the incident angle of the measurement light LS corresponding to the displacements ΔX and ΔY calculated in step S53 with reference to the table information.

(S56: Generate control information of optical scanner)
Similar to step S45, the main control unit 211 sets the scan width, scan speed, and scan center of the optical scanner 88 so that a predetermined position becomes the scan center based on the amount of change in the incident angle specified in step S55. The scan processing unit 362D is made to generate control information for changing at least one of the offset values of. The main control unit 211 controls the optical scanner 88 based on the generated control information.

This completes the process of step S15 according to the modified example of the second operation example (end).

[Action / Effect]
The action and effect of the ophthalmic apparatus according to the embodiment will be described.

The ophthalmic apparatus (1000) according to some embodiments includes an optical system (OCT optical system 8), an acquisition unit (anterior eye camera 300), an analysis unit (362), and a control unit (210, main control unit). 211) and is included. The optical system includes an optical scanner (88) and irradiates the eye to be inspected (E) with light (measurement light LS) deflected by the optical scanner. The acquisition unit acquires an image of the anterior segment of the eye to be inspected. By analyzing the anterior segment image acquired by the acquisition unit, the analysis unit identifies the corneal incident position where the above light is incident on the cornea (Cr) of the eye to be inspected and the rotation angle (θ) of the eye to be inspected. Based on the corneal incident position and the rotation angle, the retinal incident position where the above light is incident on the retina of the test eye is specified. The control unit controls the optical scanner based on the displacement of the retinal incident position with respect to the reference position (fovea) in the retina.

According to such a configuration, the corneal incident position and the rotation angle of the eye to be examined are specified from the anterior segment image, the retinal incident position is specified from the specified corneal incident position and the rotation angle, and the retinal incident position with respect to the reference position. Since the optical scanner can be controlled based on the displacement, the alignment can be performed so that the light is incident on the retina from the anterior segment image at a predetermined position. This enables tracking control from the anterior segment image to the retina. In this case, it is not necessary to directly observe the retina, and it is possible to eliminate the need for a fundus illumination system that irradiates the fundus (retina) with illumination light.

In some embodiments, the analysis unit identifies the rotation angle based on the displacement of the position corresponding to the feature region (pupil center) of the eye to be examined in the anterior segment image.

According to such a configuration, it becomes possible to provide an ophthalmic apparatus capable of highly accurate tracking control from the anterior segment image to the retina with a simple process.

In some embodiments, the analysis unit identifies at least one of a rotation angle in the first plane (in the horizontal plane) and a rotation angle in the second plane (in the vertical plane) intersecting the first plane.

According to such a configuration, the position of incidence on the retina can be specified by reflecting the rotation of at least one eye to be inspected in the first plane and the second plane, so that the optical scanner can be controlled with higher accuracy. Becomes possible.

In some embodiments, the analyzer identifies the rotation angle with eye parameters that represent the optical properties of the eye being tested or a given model eye.

According to such a configuration, it becomes possible to provide an ophthalmic apparatus capable of highly accurate tracking control from the anterior segment image to the retina with a simple process.

Some embodiments include an alignment optical system (alignment light projection system 2) that projects an alignment light flux onto the eye to be inspected, and an analysis unit is an image (Pulkiner image) formed based on the alignment light flux in the anterior segment image. The corneal incident position is specified based on.

According to such a configuration, since the incident position of the cornea is specified based on the position of the Purkinje image in the anterior segment image, the incident position of the cornea can be specified with high accuracy. As a result, it becomes possible to specify the incident position on the retina with high accuracy, and it becomes possible to perform highly accurate alignment from the anterior segment image.

Some embodiments include a moving mechanism (200) that moves relative to the eye under test and the optical system, the control unit moving based on an image formed on the anterior segment image based on the alignment luminous flux. After controlling, the optical scanner is controlled based on the above displacement.

According to such a configuration, after the alignment between the eye to be inspected and the optical system is completed with reference to the image based on the alignment luminous flux, the alignment based on the specified retina incident position becomes possible. As a result, highly accurate tracking control in the retina can be executed at an early stage.

In some embodiments, the acquisition unit includes two or more imaging units (anterior eye camera 300) that image the anterior segment from different directions substantially simultaneously, and the control unit is the position of the two or more imaging units. The movement mechanism is controlled based on the position of the above-mentioned image obtained by analyzing the two or more captured images acquired by the two or more photographing units.

With such a configuration, it becomes possible to align the eye to be inspected with the optical system in a wide dynamic range.

In some embodiments, the analyzer identifies the retinal incident position by performing ray tracing processing on the light incident on the corneal incident position using eyeball parameters representing the optical characteristics of the eye under test or a predetermined model eye. To do.

According to such a configuration, it is possible to identify the retinal incident position from the anterior segment image by a simple process.

In some embodiments, the control unit ensures that the amount of change in the displacement of the retinal incident position with respect to the reference position in the retina is within a predetermined threshold with respect to the predetermined amount of change in the incident angle of light at the corneal incident position. Control information is specified by repeating the ray tracing process, and the optical scanner is controlled based on the control information.

According to such a configuration, the optical scanner can be controlled so that a desired position can be scanned by repeating the ray tracing process.

In some embodiments, the control unit uses table information or functions corresponding to the optical characteristics of the eye to be inspected or a predetermined model eye to identify the amount of change in the incident angle of light at the corneal incident position and the identified change. The control information is specified based on the quantity, and the optical scanner is controlled based on the control information.

According to such a configuration, the optical scanner can be controlled so that the desired position can be scanned by using the table information or the function, so that the process of aligning the anterior segment image to the desired position of the retina can be performed. Can be simplified.

In some embodiments, the optical properties include corneal shape information of the eye being examined.

According to such a configuration, more accurate alignment (tracking) can be performed in consideration of the optical characteristics of the eye to be inspected.

In some embodiments, the optical system comprises a corneal shape measuring optical system (kerato measuring system 3) that projects a measurement pattern onto the eye to be inspected and detects the return light thereof, and the return obtained by the corneal shape measuring optical system. It includes a corneal shape calculation unit (222) that calculates corneal shape information of the eye to be inspected based on the light detection result.

According to such a configuration, it is possible to provide an ophthalmic apparatus capable of performing more accurate positioning (tracking) in consideration of the optical characteristics of the eye to be inspected with a simple configuration.

In some embodiments, the optical properties include the refractive power value (eye refractive power) of the eye being examined.

According to such a configuration, more accurate alignment (tracking) can be performed in consideration of the optical characteristics of the eye to be inspected.

In some embodiments, the optical system comprises a refractive power measuring optical system (refractive power measuring projection system 6, reflex measuring light receiving system 7) that projects light onto the eye to be inspected and detects the return light thereof. It includes a refractive power value calculation unit (eye refractive power calculation unit 221) that calculates the refractive power value of the eye to be inspected based on the detection result of the return light obtained by the system.

According to such a configuration, it is possible to provide an ophthalmic apparatus capable of performing more accurate positioning (tracking) in consideration of the optical characteristics of the eye to be inspected with a simple configuration.

In some embodiments, the optical properties include the intraocular distance of the eye being examined.

According to such a configuration, more accurate alignment (tracking) can be performed in consideration of the optical characteristics of the eye to be inspected.

In some embodiments, the optical system divides the light (L0) from the light source (OCT light source 101) into reference light (LR) and measurement light (LS) and receives the measurement light deflected by an optical scanner. The OCT optical system (8) that projects onto the eye to detect the interference light (LC) between the return light from the eye to be examined and the reference light is included, and the eye to be examined is based on the detection result of the interference light obtained by the OCT optical system. Includes an intraocular distance calculation unit (parameter calculation unit 361A) for calculating the intraocular distance.

According to such a configuration, it is possible to provide an ophthalmic apparatus capable of performing more accurate positioning (tracking) in consideration of the optical characteristics of the eye to be inspected with a simple configuration.

In some embodiments, the analysis unit identifies the reference position based on the detection result of the interference light obtained by the OCT optical system.

With such a configuration, it is possible to specify the retina incident position with respect to the reference position with high accuracy according to the eye to be inspected.

In some embodiments, the optical system divides the light (L0) from the light source (OCT light source 101) into reference light (LR) and measurement light (LS) and receives the measurement light deflected by an optical scanner. The OCT optical system (8) that projects the light onto the eye examination and detects the interference light (LC) between the return light from the eye to be inspected and the reference light is included, and the analysis unit uses the detection result of the interference light obtained by the OCT optical system. Identify the reference position based on.

With such a configuration, it is possible to specify the retina incident position with respect to the reference position with high accuracy according to the eye to be inspected.

<Others>
In the above embodiment, the case where the eye refractive power is acquired by projecting light onto the eye to be inspected has been described, but the configuration of the ophthalmic apparatus according to the embodiment is not limited to this. The ophthalmic apparatus according to the embodiment may acquire the ocular refractive power based on the wave surface aberration acquired by using a known wave surface sensor.

The tracking process according to the above embodiment can be applied to the alignment process between the device optical system and the eye to be inspected.

The embodiment shown above or a modification thereof is only an example for carrying out the present invention. A person who intends to carry out the present invention can make arbitrary modifications, omissions, additions, etc. within the scope of the gist of the present invention.

2 Alignment light projection system 3 Kerato measurement system 4 Fixed vision projection system 5 Anterior eye observation system 6 Reflex measurement projection system 7 Reflex measurement light receiving system 8 OCT optical system 9 Processing unit 210 Control unit 211 Main control unit 212 Storage unit 212A Intraocular Parameter 220 Calculation processing unit 221 Eye refractive index calculation unit 222 Corneal shape calculation unit 224 Image formation unit 225 Data processing unit 300 Front eye unit Camera 350 Alignment processing unit 360 Tracking processing unit 361 Eyeball model generation unit 362 Analysis unit 1000 Ophthalmic device Cr Corneal E Eye to be inspected Ef Fundus

Claims (18)

An optical system including an optical scanner that irradiates the eye to be inspected with light deflected by the optical scanner.
The acquisition unit that acquires the anterior segment image of the eye to be inspected,
By analyzing the anterior segment image acquired by the acquisition unit, the corneal incident position where the light is incident and the rotation angle of the eye to be inspected are identified in the cornea of the eye to be inspected, and the corneal incident position and the rotation are identified. An analysis unit that identifies the retinal incident position where the light is incident on the retina of the eye to be inspected based on the angle.
A control unit that controls the optical scanner based on the displacement of the incident position on the retina with respect to the reference position on the retina.
Ophthalmic equipment including. The ophthalmic apparatus according to claim 1, wherein the analysis unit identifies the rotation angle based on a displacement of a position corresponding to a characteristic portion of the eye to be inspected in the anterior segment image. The ophthalmic apparatus according to claim 1 or 2, wherein the analysis unit identifies at least one of a rotation angle in the first plane and a rotation angle in the second plane that intersects the first plane. .. The ophthalmology according to any one of claims 1 to 3, wherein the analysis unit specifies the rotation angle by using an eyeball parameter representing the optical characteristics of the eye to be inspected or a predetermined model eye. apparatus. Includes an alignment optical system that projects an alignment luminous flux onto the eye to be inspected.
The aspect according to any one of claims 1 to 4, wherein the analysis unit identifies the corneal incident position based on an image formed based on the alignment luminous flux in the anterior ocular segment image. Ophthalmic equipment. Including a moving mechanism that relatively moves the eye to be inspected and the optical system.
The claim is characterized in that the control unit controls the movement mechanism based on an image formed based on the alignment luminous flux in the front eye image, and then controls the optical scanner based on the displacement. 5. The ophthalmic apparatus according to 5. The acquisition unit includes two or more imaging units that photograph the anterior segment of the eye from different directions substantially simultaneously.
The control unit moves the moving mechanism based on the positions of the two or more photographing units and the positions of the images obtained by analyzing the two or more captured images acquired by the two or more photographing units. The ophthalmic apparatus according to claim 6, wherein the ophthalmic apparatus is controlled. The analysis unit identifies the retinal incident position by performing light tracing processing using an eyeball parameter representing the optical characteristics of the eye to be inspected or a predetermined model eye on the light incident on the corneal incident position. The ophthalmic apparatus according to any one of claims 1 to 7. The control unit traces light so that the amount of change in the displacement of the retina incident position with respect to the reference position in the retina is within a predetermined threshold value with respect to the predetermined amount of change in the incident angle of the light at the corneal incident position. The ophthalmologic apparatus according to any one of claims 1 to 8, wherein control information is specified by repeating the process, and the optical scanner is controlled based on the control information. The control unit specifies the amount of change in the incident angle of the light at the corneal incident position using table information or a function corresponding to the optical characteristics of the eye to be inspected or a predetermined model eye, and is based on the specified amount of change. The ophthalmic apparatus according to any one of claims 1 to 8, wherein the control information is specified and the optical scanner is controlled based on the control information. The ophthalmic apparatus according to claim 4, claim 8 or claim 10, wherein the optical characteristics include corneal shape information of the eye to be inspected. The optical system includes a corneal shape measurement optical system that projects a measurement pattern onto the eye to be inspected and detects the return light thereof.
The ophthalmologic apparatus according to claim 11, further comprising a corneal shape information calculation unit that calculates the corneal shape information of the eye to be inspected based on the detection result of the return light obtained by the corneal shape measurement optical system. .. The ophthalmic apparatus according to any one of claims 4 and 10 to 12, wherein the optical characteristics include a refractive power value of the eye to be inspected. The optical system includes a refractive power measurement optical system that projects light onto the eye to be inspected and detects the return light thereof.
The ophthalmic apparatus according to claim 13, further comprising a refractive power value calculation unit that calculates a refractive power value of the eye to be inspected based on a detection result of the return light obtained by the refractive power measurement optical system. The ophthalmic apparatus according to any one of claims 4 and 10 to 14, wherein the optical characteristics include an intraocular distance of the eye to be inspected. The optical system divides the light from the light source into reference light and measurement light, projects the measurement light deflected by the optical scanner onto the eye to be inspected, and causes the return light from the eye to be inspected and the reference light. Includes OCT optics to detect interference light
The ophthalmic apparatus according to claim 15, further comprising an intraocular distance calculation unit that calculates the intraocular distance of the eye to be inspected based on the detection result of the interference light obtained by the OCT optical system. The ophthalmic apparatus according to claim 16, wherein the analysis unit identifies the reference position based on the detection result of the interference light obtained by the OCT optical system. The optical system divides the light from the light source into reference light and measurement light, projects the measurement light deflected by the optical scanner onto the eye to be inspected, and causes the return light from the eye to be inspected and the reference light. Includes OCT optics to detect interference light
The ophthalmic apparatus according to any one of claims 1 to 15, wherein the analysis unit identifies the reference position based on the detection result of the interference light obtained by the OCT optical system. ..

Images