JP2023175006A - Ophthalmologic apparatus and control method thereof - Google Patents

Abstract

To provide a new technology to execute OCT measurement using an optical scanner.SOLUTION: An ophthalmologic apparatus includes a data acquisition unit, a storage unit, and a correction unit. The data acquisition unit includes an optical scanner capable of deflecting light within a predetermined deflection angle range including a linear operation range and a non-linear operation range, and acquires a first dataset group in an A scan direction by executing optical coherence tomography to an eye to be examined using measurement light deflected in a predetermined deflection direction by the optical scanner. The storage unit stores a plurality of pieces of correction data in the non-linear operation range corresponding to a plurality of scan conditions in which at least one of the deflection angle range and a deflection speed of the optical scanner differs. The correction unit generates a second dataset group by correcting at least a part of the first dataset group on the basis of any one of the plurality of pieces of correction data corresponding to the scan condition of the optical scanner.SELECTED DRAWING: Figure 11

Description

The present invention relates to an ophthalmological apparatus and a control method thereof.

2. Description of the Related Art In recent years, optical coherence tomography (OCT), which uses a light beam from a laser light source or the like to measure or image the form of an object to be measured, has been attracting attention. Since OCT is not invasive to the human body unlike X-ray CT (Computed Tomography), it is expected to be applied particularly in the medical and biological fields. For example, in the field of ophthalmology, devices that form images of the fundus, cornea, etc. have been put into practical use. A device using such OCT (OCT device) can be applied to observation of various parts of the eye to be examined (fundus of the eye and anterior segment of the eye). Additionally, because it can obtain high-definition images, it is applied to the diagnosis of various ophthalmological diseases.

In measurement (imaging) using OCT, a measurement site is scanned using measurement light deflected by an optical scanner. For example, Patent Document 1 discloses a method of ensuring linearity of a scanning trajectory by constantly performing correction calculations on a movement command value of a galvano scanner.

Japanese Patent Application Publication No. 2011-170209

In measurement using OCT, it is required to obtain measurement results with a wider angle and higher definition. Therefore, optical scanners are required to operate at higher speeds over a wider range of deflection angles. However, it is difficult for optical scanners such as galvano scanners to follow high-speed operations.

As described above, the operational characteristics of the optical scanner limit the ability to obtain desired measurement results in OCT measurement.

The present invention has been made in view of these circumstances, and its purpose is to provide a new technique for performing OCT measurement using an optical scanner.

A first aspect of some embodiments includes an optical scanner capable of deflecting light in a predetermined deflection angle range, and uses measurement light deflected in a predetermined deflection direction by the optical scanner to apply light to the eye to be examined. a data acquisition unit that acquires a first data set group in the A-scan direction by executing coherence tomography; a storage unit that stores correction data corresponding to the operating characteristics of the optical scanner; The ophthalmologic apparatus includes a correction unit that generates a second data set group by correcting at least a portion of the first data set group based on correction data.

In a second aspect of some embodiments, in the first aspect, the correction unit is configured such that the first data set group is based on measurement light deflected by the optical scanner at deflection angles at substantially equal intervals in the deflection angle range. One or more data sets of the first data set group corresponding to at least a part of the deflection angle range are corrected based on the correction data so that the data set group is acquired based on the correction data.

In a third aspect of some embodiments, in the second aspect, the optical scanner includes a mirror that reflects the measurement light, and reciprocates the mirror in a rocking direction corresponding to the deflection direction. By deflecting the measurement light in the deflection angle range, at least a part of the deflection angle range is at a first deflection angle at which the mirror starts to swing in the swing direction or in the swing direction. includes a second deflection angle at which the oscillation of the mirror ends.

In a fourth aspect of some embodiments, in any of the first to third aspects, the correction unit includes an extraction unit that extracts one or more data sets from at least a part of the first data set group. and replacing at least a portion of the first data set group with the one or more data sets.

In a fifth aspect of some embodiments, in any of the first to third aspects, the correction unit includes an interpolation unit that calculates an interpolated data set by interpolating at least a part of the first data set group. and replacing at least a portion of the first data set group with an interpolated data set calculated by the interpolation unit.

In a sixth aspect of some embodiments, in any of the first to third aspects, the correction unit includes an alignment unit that aligns at least a part of the first data set group in the A-scan direction. , an interpolation unit that calculates an interpolated data set by interpolating at least a part of the first data set group aligned by the alignment unit, It is replaced with the interpolated data set calculated by the interpolation unit.

In a seventh aspect of some embodiments, in any of the first to third aspects, the correction unit adds a new data set to the first data set group.

In an eighth aspect of some embodiments, in the seventh aspect, the new data set is generated based at least in part on the first group of data sets.

In a ninth aspect of some embodiments, in any of the first to eighth aspects, the optical scanner includes a first scanner that deflects the measurement light in a first deflection direction in a first deflection angle range; a second scanner that deflects the measurement light deflected by the first scanner toward the eye to be examined in a second deflection direction and in a second deflection angle range, and the correction unit adjusts the operation of the first scanner. a correction process for at least a portion of the first data set group based on first correction data corresponding to the characteristics; and at least one of the first data set group based on second correction data corresponding to the operating characteristics of the second scanner. It is possible to perform the correction process by switching between the correction processes for the parts.

In a tenth aspect of some embodiments, in any one of the first to ninth aspects, the storage unit corresponds to a plurality of scan conditions in which at least one of the deflection angle range and the deflection speed of the optical scanner is different. A plurality of correction data are stored, and the correction unit corrects at least a portion of the first data set group based on the correction data stored in the storage unit in accordance with the scan condition.

An eleventh aspect of some embodiments is, in any one of the first to tenth aspects, image formation in which a tomographic image of the eye to be examined is formed based on the second data set group generated by the correction unit. Including.

A twelfth aspect of some embodiments is a method of controlling an ophthalmological apparatus including an optical scanner capable of deflecting light within a predetermined deflection angle range. The method for controlling the ophthalmological apparatus includes acquiring a first data set group in the A-scan direction by performing optical coherence tomography on the eye to be examined using measurement light deflected in a predetermined deflection direction by the optical scanner. The method includes a data acquisition step, and a correction step of generating a second data set group by correcting at least a portion of the first data set group based on correction data corresponding to operating characteristics of the optical scanner.

In a thirteenth aspect of some embodiments, in the twelfth aspect, the correction step includes adjusting the first data set group to measurement light deflected by the optical scanner at deflection angles that are substantially equally spaced in the deflection angle range. One or more data sets of the first data set group corresponding to at least a part of the deflection angle range are corrected based on the correction data so that the data set group is acquired based on the correction data.

In a fourteenth aspect of some embodiments, in the thirteenth aspect, the optical scanner includes a mirror that reflects the measurement light, and reciprocates the mirror in a rocking direction corresponding to the deflection direction. By deflecting the measurement light in the deflection angle range, at least a part of the deflection angle range is at a first deflection angle at which the mirror starts to swing in the swing direction or in the swing direction. includes a second deflection angle at which the oscillation of the mirror ends.

In a fifteenth aspect of some embodiments, in any of the twelfth to fourteenth aspects, the optical scanner includes a first scanner that deflects the measurement light in a first deflection direction in a first deflection angle range; a second scanner that deflects the measurement light deflected by the first scanner toward the subject's eye in a second deflection direction in a second deflection angle range, and the correction step includes an operation of the first scanner. a correction process for at least a portion of the first data set group based on first correction data corresponding to the characteristics; and at least one of the first data set group based on second correction data corresponding to the operating characteristics of the second scanner. It is possible to perform the correction process by switching between the correction processes for the parts.

A sixteenth aspect of some embodiments is, in any one of the twelfth to fifteenth aspects, image formation in which a tomographic image of the eye to be examined is formed based on the second data set group generated in the correction step. Contains steps.

Note that it is possible to arbitrarily combine the configurations according to the plurality of claims described above.

According to the present invention, a new technique for performing OCT measurement using an optical scanner can be provided.

FIG. 1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment. FIG. 1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment. FIG. 1 is a schematic block diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment. FIG. 2 is a schematic diagram showing an example of the operating characteristics of the optical scanner according to the embodiment. It is a schematic diagram for explaining processing performed by an ophthalmologic apparatus according to an embodiment. It is a schematic diagram for explaining processing performed by an ophthalmologic apparatus according to an embodiment. FIG. 1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment. It is a schematic diagram for explaining processing performed by an ophthalmologic apparatus according to an embodiment. FIG. 1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment. It is a schematic diagram for explaining processing performed by an ophthalmologic apparatus according to an embodiment. FIG. 1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment. It is a schematic diagram for explaining processing performed by an ophthalmologic apparatus according to an embodiment. FIG. 1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment. It is a schematic diagram for explaining processing performed by an ophthalmologic apparatus according to an embodiment. It is a flow chart showing an example of operation of an ophthalmologic device concerning an embodiment. It is a flow chart showing an example of operation of an ophthalmologic device concerning an embodiment. It is a schematic block diagram showing an example of composition of an ophthalmologic device concerning a modification of an embodiment.

Embodiments of an ophthalmologic apparatus and a method for controlling an ophthalmologic apparatus according to the present invention will be described in detail with reference to the drawings. Note that the contents of the documents cited in this specification and any known technology can be incorporated into the following embodiments.

The ophthalmological apparatus according to the embodiment includes an optical scanner capable of deflecting measurement light in a predetermined deflection angle range, and performs OCT on a subject's eye using the measurement light deflected in a predetermined deflection direction by the optical scanner. Is possible. The ophthalmological apparatus acquires a data set group (first data set group) in the A-scan direction by executing OCT, and based on correction data corresponding to the operational characteristics of the optical scanner (for example, deflection angle vs. time characteristics). A new data set group (second data set group) is generated by correcting at least a portion of the data set group. In some embodiments, the data set group is a data set group of reflection intensity profile data in the A-scan direction obtained by performing Fourier transform or the like on detection data (detection results) of interference light. In some embodiments, the datasets are datasets of A-scan image data obtained by imaging reflection intensity profiles. In some embodiments, the datasets are datasets of interfering light detection data.

This makes it possible to obtain a data set group in the A-scan direction that takes into account the operating characteristics of the optical scanner. For example, it becomes possible to generate a group of data sets at uniformly distributed scanning positions from a group of data sets acquired at unevenly distributed scanning positions due to the nonlinear operation of the optical scanner. Here, the nonlinear operation of the optical scanner means an operation in which the deflection angle of the optical scanner does not change linearly with respect to changes in time (data collection timing). Furthermore, for example, it is possible to generate a data set group in which only a desired region is acquired at high density from a data set group acquired by linear operation of an optical scanner.

In the following, a case will be described in which the optical scanner includes a galvano scanner, performs linear operation in a predetermined deflection angle range, and performs nonlinear operation in another deflection angle range. However, the following embodiments can also be applied when the optical scanner performs linear operation. Moreover, although the deflection angle versus time characteristic will be explained below as an example of the operating characteristic of the optical scanner, the following embodiments can be applied to other operating characteristics of the optical scanner.

Further, although a case will be described below in which a data set group of A-scan image data is corrected, the following embodiment can also be applied to a case in which a data set group such as reflection intensity profile data is corrected.

In this specification, images acquired by OCT may be collectively referred to as OCT images. Furthermore, a measurement operation for forming an OCT image is sometimes referred to as OCT measurement.

The ophthalmologic apparatus according to some embodiments includes any one or more of an ophthalmologic imaging device, an ophthalmologic measurement device, and an ophthalmologic treatment device. The ophthalmologic imaging device included in the ophthalmologic apparatus of some embodiments is, for example, one or more of a fundus camera, a scanning laser ophthalmoscope, a slit lamp ophthalmoscope, a surgical microscope, and the like. In addition, the ophthalmological measuring device included in the ophthalmological apparatus of some embodiments is, for example, any one or more of an eye refraction test device, a tonometer, a specular microscope, a wavefront analyzer, a perimeter, a microperimeter, etc. It is. Further, the ophthalmic treatment device included in the ophthalmologic device of some embodiments is, for example, one or more of a laser treatment device, a surgical device, a surgical microscope, and the like.

The ophthalmological apparatus according to the following embodiments includes an OCT apparatus capable of OCT measurement and a fundus camera. Further, it is also possible to incorporate the configuration according to the following embodiments into a single OCT apparatus.

In the following, an ophthalmologic apparatus capable of performing OCT measurement on the fundus of an eye to be examined will be described as an example, but the ophthalmologic apparatus according to the embodiment may also be capable of OCT measurement on the anterior segment of the eye to be examined. In some embodiments, the OCT measurement range or measurement site is changed by moving a lens that changes the focal position of the measurement light. In some embodiments, the addition of one or more attachments (objective lens, anterior lens, etc.) enables OCT measurements of the fundus, OCT measurements of the anterior segment, and OCT of the entire eye, including the fundus and anterior segment. This configuration allows measurement. In some embodiments, in an ophthalmological apparatus for fundus measurement, a front lens is disposed between an objective lens and a subject's eye, so that measurement light that is made into a parallel beam is incident on the subject's eye, thereby measuring the anterior segment of the eye. Perform OCT measurement for.

<Configuration>
〔Optical system〕
As shown in FIG. 1, the ophthalmologic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The fundus camera unit 2 is provided with an optical system and a mechanism for acquiring a frontal image of the eye E to be examined. The OCT unit 100 is provided with an optical system and part of a mechanism for performing OCT. Other parts of the optical system and mechanism for performing OCT are provided in the fundus camera unit 2. Arithmetic control unit 200 includes one or more processors that perform various calculations and controls. In addition to these, optional elements such as members for supporting the subject's face (chin rest, forehead rest, etc.) and lens units for switching the target area of OCT (for example, attachment for anterior segment OCT) or a unit may be provided in the ophthalmologic apparatus 1. In some embodiments, the lens unit is configured to be manually inserted and removed between the eye E and an objective lens 22, which will be described later. In some embodiments, the lens unit is configured to be automatically inserted and removed between the eye E and an objective lens 22, which will be described later, under control from a control unit 210, which will be described later.

In this specification, "processor" refers to, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (e.g. , SPLD (Simple Programmable Logic Device), CPLD (Complex It means a circuit such as a programmable logic device (programmable logic device) or FPGA (field programmable gate array). The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a storage circuit or a storage device.

[Fundus camera unit]
The fundus camera unit 2 is provided with an optical system for photographing the fundus Ef of the eye E to be examined. The acquired image of the fundus Ef (referred to as a fundus image, fundus photograph, etc.) is a frontal image such as an observation image or a photographed image. Observation images are obtained by video shooting using near-infrared light. The photographed image is a still image using flash light. Furthermore, the fundus camera unit 2 can photograph the anterior segment Ea of the eye E to be examined to obtain a frontal image (anterior segment image).

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

The light (observation illumination light) output from the observation light source 11 of the illumination optical system 10 is reflected by the reflection mirror 12 having a curved reflection surface, passes through the condensing lens 13, and passes through the visible cut filter 14. It becomes near-infrared light. Further, the observation illumination light is once converged near the photographing light source 15, reflected by a mirror 16, and passes through relay lenses 17, 18, an aperture 19, and a relay lens 20. The observation illumination light is reflected at the periphery of the apertured mirror 21 (the area around the aperture), passes through the dichroic mirror 46, is refracted by the objective lens 22, and is refracted by the objective lens 22. Part Ea) is illuminated. The return light of the observation illumination light from the subject's eye E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central region of the perforated mirror 21, and passes through the dichroic mirror 55. . The returning light that has passed through the dichroic mirror 55 passes through the photographic focusing lens 31 and is reflected by the mirror 32. Further, this returned light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged by the condenser lens 34 on the light receiving surface of the image sensor 35. The image sensor 35 detects the returned light at a predetermined frame rate. Note that the focus of the photographing optical system 30 is adjusted to match the fundus Ef or the anterior segment Ea.

The light output from the photographing light source 15 (photographing illumination light) passes through the same path as the observation illumination light and is irradiated onto the fundus Ef. The return light of the imaging illumination light from the eye E is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by the mirror 36, and is reflected by the condenser lens 37. An image is formed on the light receiving surface of the image sensor 38.

An LCD (Liquid Crystal Display) 39 displays a fixation target and a visual acuity measurement target. A portion of the light beam output from the LCD 39 is reflected by the half mirror 33A, then reflected by the mirror 32, passes through the photographic focusing lens 31 and the dichroic mirror 55, and then passes through the hole of the perforated mirror 21. The light beam that has passed through the hole of the perforated mirror 21 is transmitted through the dichroic mirror 46, refracted by the objective lens 22, and projected onto the fundus Ef.

By changing the display position of the fixation target on the screen of the LCD 39, the fixation position of the eye E to be examined can be changed. Examples of fixation positions include a fixation position for acquiring an image centered on the macula, a fixation position for acquiring an image centered on the optic disc, and a fixation position for acquiring an image centered on the optic disc, and the center of the fundus between the macula and optic disc. There is a fixation position for acquiring an image centered on the macula, and a fixation position for acquiring an image of a region far away from the macula (periphery of the fundus). The ophthalmological apparatus 1 according to some embodiments includes a GUI (Graphical User Interface) and the like for specifying at least one of such fixation positions. The ophthalmologic apparatus 1 according to some embodiments includes a GUI, etc. for manually moving the fixation position (the display position of the fixation target).

The configuration for presenting a movable fixation target to the eye E to be examined is not limited to a display device such as an LCD. For example, a movable fixation target can be generated by selectively lighting up a plurality of light sources in a light source array (such as a light emitting diode (LED) array). Furthermore, a movable fixation target can be generated using one or more movable light sources.

Additionally, the ophthalmological device 1 may be provided with one or more external fixation light sources. One of the one or more external fixation light sources is capable of projecting fixation light onto the companion eye of the eye E to be examined. The projection position of the fixation light on the companion eye can be changed. By changing the projection position of the fixation light to the companion eye, the fixation position of the eye E to be examined can be changed. The fixation position by the external fixation light source may be the same as the fixation position of the eye E using the LCD 39. For example, a movable fixation target can be generated by selectively lighting up a plurality of external fixation light sources. Furthermore, a movable fixation target can be generated by one or more movable external fixation light sources.

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

The focus optical system 60 generates a split index used for focus adjustment for the eye E to be examined. The focus optical system 60 is moved along the optical path of the illumination optical system 10 (illumination optical path) in conjunction with the movement of the photographic focusing lens 31 along the optical path of the photographic optical system 30 (photographic optical path). The reflection rod 67 can be inserted into and removed from the illumination optical path. When performing focus adjustment, the reflective surface of the reflective rod 67 is arranged at an angle to the illumination optical path. The focus light output from the LED 61 passes through a relay lens 62 , is separated into two beams by a split indicator plate 63 , passes through a two-hole diaphragm 64 , is reflected by a mirror 65 , and is reflected by a condensing lens 66 into a reflecting rod 67 . Once the image is formed on the reflective surface of the image, it is reflected. Further, the focus light passes through the relay lens 20, is reflected by the apertured mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef. The fundus reflected light of the focus light is guided to the image sensor 35 through the same path as the corneal reflected light of the alignment light. Manual focus or autofocus can be performed based on the received light image (split index image).

The dichroic mirror 46 combines the fundus imaging optical path and the OCT optical path. The dichroic mirror 46 reflects light in a wavelength band used for OCT and transmits light for fundus photography. The OCT optical path (the optical path of measurement light) includes, in order from the OCT unit 100 side to the dichroic mirror 46 side, a collimator lens unit 40, an optical path length changing section 41, an optical scanner 42, an OCT focusing lens 43, a mirror 44, and a relay lens 45 are provided.

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

The optical scanner 42 is arranged at a position optically conjugate with the pupil of the eye E to be examined. The optical scanner 42 deflects the measurement light LS passing through the OCT optical path. The optical scanner 42 can deflect the measurement light LS one-dimensionally or two-dimensionally.

In the case of one-dimensional deflection, the optical scanner 42 includes a galvano scanner that deflects the measurement light LS in a predetermined deflection direction and within a predetermined deflection angle range. In the case of two-dimensional deflection, the optical scanner 42 includes a first galvano scanner and a second galvano scanner. The first galvano scanner deflects the measurement light LS so as to scan the imaging region (fundus Ef or anterior segment) in a horizontal direction perpendicular to the optical axis of the OCT optical system 8. The second galvano scanner deflects the measurement light LS deflected by the first galvano scanner so as to scan the imaging region in a vertical direction perpendicular to the optical axis of the OCT optical system 8. Examples of the scanning mode of the measurement light LS by the optical scanner 42 include horizontal scanning, vertical scanning, cross scanning, radial scanning, circular scanning, concentric scanning, and spiral scanning.

The OCT focusing lens 43 is moved along the optical path of the measurement light LS in order to perform focus adjustment of the optical system for OCT. The OCT focusing lens 43 has a first lens position for arranging the focal position of the measurement light LS at or near the fundus Ef of the eye E to be examined, and for converting the measurement light LS irradiated onto the eye E to a parallel light beam. It is movable within a movement range that includes the second lens position. Movement of the imaging focusing lens 31, movement of the focusing optical system 60, and movement of the OCT focusing lens 43 can be controlled in a coordinated manner.

[OCT unit]
An example of the configuration of the OCT unit 100 is shown in FIG. The OCT unit 100 is provided with an optical system for acquiring an OCT image of the eye E to be examined. This optical system splits light from a wavelength swept type (wavelength scanning type) light source into measurement light and reference light, and causes interference between the return light of the measurement light from the eye E and the reference light that has passed through the reference optical path. This is an interference optical system that generates interference light and detects this interference light. The detection result (detection signal) of the interference light by the interference optical system is an interference signal indicating the spectrum of the interference light, and is sent to the arithmetic and control unit 200.

The light source unit 101 is configured to include a wavelength sweep type (wavelength scanning type) light source that can sweep (scan) the wavelength of emitted light, similar to a general swept source type ophthalmological apparatus. The wavelength swept light source includes a laser light source including a resonator. The light source unit 101 temporally changes the output wavelength in a near-infrared wavelength band that is invisible to the human eye.

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

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

The reference light LR is guided to a collimator 111 by an optical fiber 110 and becomes a parallel light beam. The reference light LR, which has become a parallel light beam, is guided to the optical path length changing section 114. The optical path length changing unit 114 is movable in the direction of the arrow shown in FIG. 2, and changes the optical path length of the reference light LR. This movement changes the length of the optical path of the reference light LR. This change in the optical path length is used for correcting the optical path length according to the axial length of the eye E to be examined, adjusting the interference state, and the like. The optical path length changing unit 114 includes, for example, a corner cube and a moving mechanism that moves the corner cube. In this case, the corner cube of the optical path length changing unit 114 turns back the traveling direction of the reference light LR, which has been made into a parallel light beam by the collimator 111, in the opposite direction. The optical path of the reference light LR entering the corner cube and the optical path of the reference light LR exiting from the corner cube are parallel.

In the configuration shown in FIGS. 1 and 2, an optical path length changing unit 41 for changing the length of the optical path of the measurement light LS (measurement optical path, measurement arm) and an optical path of the reference light LR (reference optical path, reference An optical path length changing section 114 for changing the length of the arm) is provided. However, only one of the optical path length changing sections 41 and 114 may be provided. It is also possible to change the difference between the reference optical path length and the measurement optical path length using optical members other than these.

The reference light LR that has passed through the optical path length changing unit 114 is converted from a parallel light beam into a convergent light beam by a collimator 116 and enters an optical fiber 117 .

An optical path length correction member may be disposed on at least one of the reference optical path between the collimator 111 and the optical path length changing unit 114 and the reference optical path between the collimator 116 and the optical path length changing unit 114. The optical path length correction member acts as a delay means for matching the optical path length (optical distance) of the reference light LR with the optical path length of the measurement light LS.

The reference light LR incident on the optical fiber 117 is guided to a polarization controller 118, and its polarization state is adjusted. The polarization controller 118 has, for example, a similar configuration to the polarization controller 103. The reference light LR whose polarization state has been adjusted by the polarization controller 118 is guided to the attenuator 120 through the optical fiber 119, and the light amount is adjusted under the control of the arithmetic and control unit 200. The reference light LR whose light intensity has been adjusted by the attenuator 120 is guided to the fiber coupler 122 through the optical fiber 121.

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

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

The detector 125 includes, for example, a pair of photodetectors that respectively detect a pair of interference lights LC, and is a balanced photodiode that outputs a difference between detection results obtained by these photodetectors. The detector 125 sends the detection result (interference signal) to a DAQ (Data Acquisition System) 130. The DAQ 130 is supplied with a clock KC from the light source unit 101. The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept (scanned) within a predetermined wavelength range by the wavelength sweep type light source. For example, the light source unit 101 optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then outputs the clock KC based on the result of detecting these combined lights. generate. The DAQ 130 samples the detection result of the detector 125 based on the clock KC. The DAQ 130 sends the sampled detection results of the detector 125 to the arithmetic control unit 200. The arithmetic and control unit 200 calculates the reflection intensity profile at each A line by, for example, performing Fourier transform on the spectral distribution based on the detection result obtained by the detector 125 for each series of wavelength scans (for each A line). Form. Furthermore, the arithmetic and control unit 200 forms image data by imaging the reflection intensity profile of each A-line.

[Calculation control unit]
The arithmetic control unit 200 analyzes the detection signal input from the DAQ 130 and forms an OCT image of the fundus Ef. The arithmetic processing for this purpose is similar to that of a conventional swept source type OCT device.

Further, the arithmetic control unit 200 controls each part of the fundus camera unit 2, the display device 3, and the OCT unit 100.

In order to control the fundus camera unit 2, the arithmetic control unit 200 controls the operation of the observation light source 11, the photographing light source 15, and the LEDs 51 and 61, controls the operation of the LCD 39, controls the movement of the photographic focusing lens 31, and controls the OCT focusing lens 43. It performs movement control, movement control of the reflecting rod 67, movement control of the focus optical system 60, movement control of the optical path length changing section 41, operation control of the optical scanner 42, and the like.

To control the display device 3, the arithmetic control unit 200 causes the display device 3 to display an OCT image of the eye E to be examined.

To control the OCT unit 100, the arithmetic control unit 200 controls the operation of the light source unit 101, the movement of the optical path length changing section 114, the attenuator 120, the polarization controllers 103 and 118, and the detector 125. control, and controls the operation of the DAQ130.

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

The fundus camera unit 2, display device 3, OCT unit 100, and arithmetic control unit 200 may be configured integrally (that is, in a single housing), or may be configured separately in two or more housings. may have been done.

[Control system]
FIG. 3 shows an example of the configuration of the control system of the ophthalmologic apparatus 1. In FIG. 3, some of the components included in the ophthalmologic apparatus 1 are omitted.

(control unit)
The control unit 210 executes various controls. Control section 210 includes a main control section 211 and a storage section 212.

(Main control part)
The main control unit 211 includes a processor and controls each part of the ophthalmologic apparatus 1 . For example, the main control unit 211 controls the focusing drive units 31A and 43A of the fundus camera unit 2, the image sensors 35 and 38, the LCD 39, the optical path length changing unit 41, the optical scanner 42, the entire optical system (moving mechanism 150), etc. Control. Furthermore, the main control section 211 controls the light source unit 101, the optical path length changing section 114, the attenuator 120, the polarization controllers 103 and 118, the detector 125, the DAQ 130, etc. of the OCT unit 100.

For example, the main control unit 211 displays a fixation target at a position on the screen of the LCD 39 that corresponds to a fixation position that is manually or automatically set. Further, the main control unit 211 can change the display position of the fixation target displayed on the LCD 39 (continuously or stepwise). Thereby, the fixation target can be moved (that is, the fixation position can be changed). The display position and movement mode of the fixation target are set manually or automatically. Manual settings are performed using, for example, a GUI. The automatic setting is performed, for example, by the data processing unit 230.

The focus drive section 31A moves the photographic focusing lens 31 in the optical axis direction of the photographic optical system 30, and also moves the focus optical system 60 in the optical axis direction of the illumination optical system 10. Thereby, the focusing position of the photographing optical system 30 is changed. The focus drive section 31A may have a mechanism for moving the photographic focusing lens 31 and a mechanism for moving the focus optical system 60, separately. The focus drive unit 31A is controlled when performing focus adjustment.

The focusing drive unit 43A moves the OCT focusing lens 43 in the optical axis direction of the measurement optical path. Thereby, the focal position of the measurement light LS is changed. For example, by moving the OCT focusing lens 43 to the first lens position, the focal position of the measurement light LS can be placed at or near the fundus Ef. For example, by moving the OCT focusing lens 43 to the second lens position, the focal position of the measurement light LS can be placed at the far point position, and the measurement light LS can be made into a parallel light beam. The focal position of the measurement light LS corresponds to the depth position (z position) of the beam waist of the measurement light LS.

The moving mechanism 150 moves at least the fundus camera unit 2 (optical system) three-dimensionally, for example. In a typical example, the moving mechanism 150 includes at least a mechanism for moving the fundus camera unit 2 in the x direction (horizontal direction), a mechanism for moving the fundus camera unit 2 in the y direction (vertical direction), and a mechanism for moving the fundus camera unit 2 in the z direction (depth direction). , and a mechanism for moving in the front-back direction). The mechanism for moving in the x direction includes, for example, an x stage movable in the x direction and an x movement mechanism that moves the x stage. The mechanism for moving in the y direction includes, for example, a y stage that is movable in the y direction, and a y movement mechanism that moves the y stage. The mechanism for moving in the z direction includes, for example, a z stage that is movable in the z direction and a z moving mechanism that moves the z stage. Each moving mechanism includes an actuator such as a pulse motor, and operates under control from the main control unit 211.

Control over the moving mechanism 150 is used for alignment and tracking. Tracking refers to moving the optical system of the apparatus in accordance with the eyeball movement of the eye E to be examined. When tracking is performed, alignment and focus adjustment are performed in advance. Tracking is a function that maintains a suitable positional relationship that is aligned and in focus by causing the position of the device optical system to follow the movement of the eyeballs. In some embodiments, the movement mechanism 150 is configured to be controlled to change the optical path length of the reference beam (and thus the optical path length difference between the optical path of the measurement beam and the optical path of the reference beam).

In the case of manual alignment, the optical system and the eye E are moved relative to each other by a user operating the user interface 240 (described later) so that the displacement of the eye E with respect to the optical system is canceled. For example, the main control unit 211 outputs a control signal corresponding to the operation content on the user interface 240 to the moving mechanism 150, thereby controlling the moving mechanism 150 to relatively move the optical system and the eye E to be examined.

In the case of auto-alignment, the main control unit 211 controls the moving mechanism 150 to relatively move the optical system and the eye E so that the displacement of the eye E with respect to the optical system is canceled. In some embodiments, the main control unit 211 sends a control signal so that the optical axis of the optical system substantially coincides with the axis of the eye E to be examined, and the distance of the optical system to the eye E to be examined becomes a predetermined working distance. By outputting this to the moving mechanism 150, the moving mechanism 150 is controlled to relatively move the optical system and the eye E to be examined. Here, the working distance is a default value also called the working distance of the objective lens 22, and corresponds to the distance between the eye E to be examined and the optical system at the time of measurement using the optical system (during photographing).

The main control unit 211 controls fundus imaging and anterior segment imaging by controlling the fundus camera unit 2 and the like. The main control unit 211 also controls OCT measurement by controlling the fundus camera unit 2, the OCT unit 100, and the like. The main control unit 211 can execute a plurality of preliminary operations before performing OCT measurement. Preliminary operations include alignment, coarse focus adjustment, polarization adjustment, and fine focus adjustment. The plurality of preliminary operations are performed in a predetermined order. In some embodiments, the preliminary operations are performed in the order described above.

Note that the type and order of the preliminary operations are not limited to these and are arbitrary. For example, a preliminary operation for determining whether or not the eye E to be examined has a small pupil (small pupil determination) can be added to the preliminary operation. The small pupil determination is performed, for example, between coarse focus adjustment and optical path length difference adjustment. In some embodiments, the small pupil determination includes the following series of processes: obtaining a frontal image (anterior segment image) of the eye E to be examined; specifying an image region corresponding to the pupil; Process for determining the size of the pupil area (diameter, circumference, etc.); Process for determining whether the eye has a small pupil based on the determined size (threshold processing); If it is determined that the eye has a small pupil, the aperture 19 is Process to control. Some embodiments further include a process of approximating the pupil area to a circle or an ellipse to determine the pupil size.

The coarse focus adjustment is focus adjustment using a split index. Note that by determining the position of the photographing focusing lens 31 based on information associating the eye refractive power and the position of the photographing focusing lens 31 acquired in advance and the measured value of the refractive power of the eye E, You can also make rough focus adjustments.

The focus fine adjustment is performed based on the interference sensitivity of OCT measurement. For example, by monitoring the interference intensity (interference sensitivity) of the interference signal obtained by OCT measurement of the eye E, the position of the OCT focusing lens 43 where the interference intensity is maximum is determined, and the OCT focusing lens 43 is focused at that position. By moving the focusing lens 43, fine focus adjustment can be performed.

In the optical path length difference adjustment, control is performed so that a predetermined position in the eye E to be examined becomes the reference position of the measurement range in the depth direction. This control is performed on at least one of the optical path length changing sections 41 and 114. Thereby, the optical path length difference between the measurement optical path and the reference optical path is adjusted. By setting the reference position by adjusting the optical path length difference, OCT measurement can be performed with high accuracy over a desired measurement range in the depth direction simply by changing the wavelength sweep speed.

In the polarization adjustment, the polarization state of the reference light LR is adjusted to optimize the interference efficiency between the measurement light LS and the reference light LR.

(Storage part)
The storage unit 212 stores various data. Examples of the data stored in the storage unit 212 include image data of an OCT image, image data of a fundus image, image data of an anterior segment image, and eye information to be examined. The eye information to be examined includes information regarding the examinee such as a patient ID and name, and information regarding the eye to be examined such as left eye/right eye identification information.

Further, the storage unit 212 stores correction data 212A. The correction data 212A is data for correcting the data set group in the A-scan direction acquired by performing OCT. The correction data 212A is data corresponding to the deflection angle versus time characteristic (in a broad sense, operational characteristic) of the optical scanner 42. In some embodiments, the storage unit 212 stores a plurality of correction data 212A corresponding to a plurality of scan conditions in which at least one of the deflection angle range and the deflection speed (scanning frequency) of the optical scanner 42 differs.

Furthermore, the storage unit 212 stores various programs and data for operating the ophthalmologic apparatus 1.

(Data processing section)
The data processing unit 230 processes data acquired by photographing the eye E to be examined and performing OCT measurement. The data processing section 230 includes an image forming section 231 and a correction section 232.

(Image forming section)
The image forming unit 231 forms an OCT image (image data) of the eye E to be examined based on sampling data obtained by sampling the detection signal from the detector 125 with the DAQ 130. OCT images formed by the image forming unit 231 include A-scan images, B-scan images (tomographic images), C-scan images, and the like. Similar to conventional swept source type OCT, this processing includes processing such as noise removal (noise reduction), filter processing, dispersion compensation, and FFT (Fast Fourier Transform). In the case of other types of OCT devices, the image forming unit 231 executes known processing depending on the type.

The image forming section 231 is configured to include, for example, the above-mentioned circuit board. Note that in this specification, "image data" and "images" based on the same may be equated.

For example, the data processing section 230 performs various image processing and analysis processing on the image formed by the image forming section 231. For example, the data processing unit 230 executes various correction processes such as image brightness correction. Further, the data processing unit 230 performs various image processing and analysis processing on the images (fundus image, anterior segment image, etc.) obtained by the fundus camera unit 2.

The data processing unit 230 executes known image processing such as interpolation processing for interpolating pixels between tomographic images to form image data of a three-dimensional image of the fundus Ef. Note that the image data of a three-dimensional image means image data in which pixel positions are defined by a three-dimensional coordinate system. Image data of a three-dimensional image includes image data consisting of voxels arranged three-dimensionally. This image data is called volume data or voxel data. When displaying an image based on volume data, the data processing unit 230 performs rendering processing (volume rendering, MIP (Maximum Intensity Projection), etc.) on this volume data so that the image can be viewed from a specific viewing direction. image data of a pseudo three-dimensional image is created. This pseudo three-dimensional image is displayed on a display device such as the display section 240A.

It is also possible to form stack data of a plurality of tomographic images as image data of a three-dimensional image. Stack data is image data obtained by three-dimensionally arranging a plurality of tomographic images obtained along a plurality of scan lines based on the positional relationship of the scan lines. In other words, stack data is image data obtained by expressing multiple tomographic images, which were originally defined by individual two-dimensional coordinate systems, using one three-dimensional coordinate system (that is, embedding them in one three-dimensional space). be.

The data processing unit 230 performs various types of rendering on the acquired three-dimensional data set (volume data, stack data, etc.) to create a B-mode image (longitudinal image, axial cross-sectional image) in an arbitrary cross section, It is possible to form C-mode images (cross-sectional images, horizontal sectional images), projection images, shadowgrams, and the like. An image of an arbitrary cross section, such as a B-mode image or a C-mode image, is formed by selecting pixels (pixels, voxels) on a specified cross-section from a three-dimensional data set. A projection image is formed by projecting a three-dimensional data set in a predetermined direction (z direction, depth direction, axial direction). A shadowgram is formed by projecting a part of a three-dimensional data set (for example, partial data corresponding to a specific layer) in a predetermined direction. An image, such as a C-mode image, a projection image, or a shadowgram, whose viewpoint is the front side of the subject's eye is called an en-face image.

The data processing unit 230 generates a B-mode image or a frontal image (vessel-enhanced image, angiogram) in which retinal blood vessels and choroidal blood vessels are emphasized based on data collected in time series by OCT (for example, B-scan image data). can be constructed. For example, time-series OCT data can be collected by repeatedly scanning substantially the same region of the eye E to be examined.

In some embodiments, the data processing unit 230 compares time-series B-scan images obtained by B-scans of substantially the same region, and converts the pixel values of the portions where the signal intensity changes into pixel values corresponding to the changes. By performing the conversion, an enhanced image is constructed in which the changed portion is emphasized. Furthermore, the data processing unit 230 forms an OCTA image by extracting information for a predetermined thickness at a desired region from the constructed plurality of emphasized images and constructing it as an en-face image.

Images generated by the data processing unit 230 (for example, three-dimensional images, B-mode images, C-mode images, projection images, shadowgrams, and OCTA images) are also included in OCT images.

Furthermore, the data processing unit 230 analyzes the detection results of the interference light obtained by OCT measurement and determines the focus state of the measurement light LS in the focus fine adjustment control. For example, the main control unit 211 performs repetitive OCT measurements while controlling the focus drive unit 43A according to a predetermined algorithm. The data processing unit 230 calculates a predetermined evaluation value regarding the image quality of the OCT image by analyzing the detection results of the interference light LC repeatedly obtained by OCT measurement. The data processing unit 230 determines whether the calculated evaluation value is less than or equal to a threshold value. In some embodiments, focus fine adjustment is continued until the calculated evaluation value becomes less than or equal to a threshold value. That is, when the evaluation value is less than or equal to the threshold value, it is determined that the focus state of the measurement light LS is appropriate, and the focus fine adjustment is continued until it is determined that the focus state of the measurement light LS is appropriate.

In some embodiments, the main control unit 211 performs repeated OCT measurements as described above to obtain interference signals, and monitors the strength of the sequentially obtained interference signals (interference intensity, interference sensitivity). do. Furthermore, by moving the OCT focusing lens 43 while performing this monitoring process, the position of the OCT focusing lens 43 where the interference intensity is maximized is searched for. According to such focus fine adjustment, the OCT focusing lens 43 can be guided to a position where the interference intensity is optimized.

Further, the data processing unit 230 analyzes the detection result of the interference light obtained by OCT measurement and determines the polarization state of at least one of the measurement light LS and the reference light LR. For example, the main control unit 211 performs repetitive OCT measurements while controlling at least one of the polarization controllers 103 and 118 according to a predetermined algorithm. In some embodiments, the main control unit 211 controls the attenuator 120 to change the amount of attenuation of the reference light LR. The data processing unit 230 calculates a predetermined evaluation value regarding the image quality of the OCT image by analyzing the detection results of the interference light LC repeatedly obtained by OCT measurement. The data processing unit 230 determines whether the calculated evaluation value is less than or equal to a threshold value. This threshold value is set in advance. Polarization adjustment is continued until the calculated evaluation value becomes equal to or less than the threshold value. That is, when the evaluation value is less than or equal to the threshold value, it is determined that the polarization state of the measurement light LS is appropriate, and polarization adjustment is continued until it is determined that the polarization state of the measurement light LS is appropriate.

In some embodiments, the main controller 211 can monitor the interference intensity even during polarization adjustment.

Further, the data processing unit 230 performs a predetermined analysis process on the detection result of interference light obtained by OCT measurement or the OCT image formed based on the detection result. The predetermined analysis process includes identifying a predetermined region (tissue, lesion) in the eye E; calculating the distance (interlayer distance), area, angle, ratio, and density between the specified regions; and using a specified calculation formula. identification of the shape of a predetermined part; calculation of these statistical values; calculation of the distribution of measured values and statistical values; and image processing based on the results of these analysis processes. Predetermined tissues include blood vessels, optic disc, fovea, macula, and the like. Predetermined lesions include vitiligo, hemorrhage, and the like.

(Correction section)
The correction unit 232 generates a new data set group in the A-scan direction by correcting the data set group in the A-scan direction formed by the image forming unit 231 based on the correction data 212A. In some embodiments, the correction unit 232 is capable of correcting at least a portion of the data set group in the A-scan direction based on correction data stored in the storage unit 212 in accordance with the scan conditions.

4 to 6 are explanatory diagrams of the operation of the correction unit 232 according to the embodiment. FIG. 4 schematically represents the deflection angle versus time characteristic of the optical scanner 42. In FIG. 4, the horizontal axis represents time corresponding to the A-scan execution timing (data set acquisition timing), and the vertical axis represents the deflection angle. FIG. 5 is a diagram for explaining the correction operation by the correction section 232. FIG. 6 schematically represents a tomographic image of the fundus Ef of the eye E to be examined. In addition, in FIG. 6, the number of A scans in the tomographic images IMG0 and IMG1 is an example, and is not limited to that number.

The optical scanner 42 includes a mirror that reflects the measurement light LS, and deflects the measurement light LS within a predetermined deflection angle range by reciprocating the mirror in a swing direction corresponding to a predetermined deflection direction. As shown in FIG. 4, the deflection angle range is a range between the deflection start angle rs (first deflection angle) and the deflection end angle re (second deflection angle). Such optical scanner 42 includes a galvano scanner, a resonant mirror, and the like. That is, as shown in FIG. 4, the deflection angle range by the optical scanner 42 includes a linear operation range R0 in which the deflection angle changes approximately linearly with respect to a change in data set acquisition timing (time change); Nonlinear operation ranges R1 and R2 are included in which the deflection angle does not change linearly with respect to changes in data set acquisition timing. The nonlinear operation range R1 includes the deflection start angle rs. The nonlinear operation range R2 includes the deflection end angle re.

A tomographic image IMG0 as shown in FIG. 6 is obtained from the data set group in the A-scan direction obtained by deflecting the measurement light LS in the deflection angle range shown in FIG. In the tomographic image IMG0 shown in FIG. 6, due to the nonlinear operation of the optical scanner 42, the change in the deflection angle becomes small in the nonlinear operation ranges R1 and R2, so that the scanning position of the data set group acquired at equal intervals in time is The spacing becomes narrower. On the other hand, since the deflection angle changes at approximately equal intervals in the linear operation range R0, the scanning positions of the data set group acquired at equal intervals in time become equal intervals. Therefore, in practice, it is not possible to form a tomographic image using the datasets acquired in the nonlinear operating ranges R1 and R2, and it is not possible to form a tomographic image using the datasets acquired in the linear operating range R0. I have no choice but to. Increasing the deflection speed required for wide-angle, high-definition OCT measurement results in an expansion of the nonlinear operating range, which means that it is not possible to respond to even higher deflection speeds.

On the other hand, as shown in FIG. 5, the correction unit 232 corrects the data set group according to the operating characteristics of the optical scanner 42 so as to cancel the uneven distribution of the scanning positions. That is, the correction unit 232 makes the data set group obtained by OCT become a data set group acquired based on the measurement light LS deflected by the optical scanner 42 at deflection angles at approximately equal intervals in the deflection angle range. , one or more data sets corresponding to at least part of the deflection angle range (nonlinear operation ranges R1, R2) among the data set group are corrected based on the correction data.

A tomographic image IMG1 as shown in FIG. 6 is obtained from the new data set group generated by the correction unit 232. The tomographic image IMG1 shown in FIG. 6 is formed from a data set group acquired by the measurement light LS deflected at substantially equal deflection angles in the deflection angle range, regardless of the nonlinear operation of the optical scanner 42 described above. Therefore, it becomes possible to form a tomographic image using a data set group acquired not only in the linear motion range R0 but also in (at least part of) the nonlinear motion ranges R1 and R2. This means that even if the deflection speed is increased, a part of the nonlinear operation range can be utilized, so that it is possible to respond to even higher deflection speeds.

The correction unit 232 can correct the data set group in various ways.

(First operation example)
FIG. 7 shows a block diagram of a configuration example of the correction unit 232 according to the first operation example of the embodiment.

The correction section 232 includes an extraction section 232A. The extraction unit 232A extracts one or more data sets from at least a portion of the data set group obtained by performing OCT. The correction unit 232 generates a new data set group by replacing at least part of the data set group obtained by performing OCT with one or more data sets extracted by the extraction unit 232A.

FIG. 8 shows an explanatory diagram of the operation of the correction unit 232 according to the first operation example of the embodiment. In FIG. 8, parts similar to those in FIG. 5 are designated by the same reference numerals, and description thereof will be omitted as appropriate.

The extraction unit 232A extracts one or more data sets such that the deflection angles are at equal intervals. At this time, the extraction unit 232A can extract the data set closest to the data set corresponding to the desired deflection angle in the nonlinear operating range R1 or R2 in the deflection angle vs. time characteristic of the optical scanner 42. That is, the extraction unit 232A can extract one or more data sets selected by the nearest neighbor method.

(Second operation example)
FIG. 9 shows a block diagram of a configuration example of the correction unit 232 according to the second operation example of the embodiment.

The correction section 232 includes an interpolation section 232B. The interpolation unit 232B calculates an interpolated data set by interpolating at least a portion of the data set group obtained by performing OCT. The correction unit 232 generates a new data set group by replacing at least part of the data set group obtained by performing OCT with the interpolated data set calculated by the interpolation unit 232B.

FIG. 10 shows an explanatory diagram of the operation of the correction unit 232 according to the second operation example of the embodiment. In FIG. 10, parts similar to those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The interpolation unit 232B calculates an interpolated data set by interpolating at least a portion of the data set group obtained by performing OCT so that the deflection angles are at equal intervals. At this time, the interpolation unit 232B linearly interpolates the data sets on both sides adjacent to the data set corresponding to the desired deflection angle in the nonlinear operation range R1 or R2 in the deflection angle vs. time characteristic of the optical scanner 42, thereby creating an interpolated data set. Calculate. In some embodiments, the interpolator 232B averages data sets within a predetermined range including data sets corresponding to a desired deflection angle in the nonlinear operating range R1 or R2 in the deflection angle vs. time characteristic of the optical scanner 42. An interpolated data set is calculated by

(Third operation example)
FIG. 11 shows a block diagram of a configuration example of the correction unit 232 according to the third operation example of the embodiment.

The correction section 232 includes a positioning section 232C and an interpolation section 232D. The alignment unit 232C aligns at least a portion of the data set group obtained by performing OCT in the A-scan direction. The interpolation unit 232D calculates an interpolated data set by interpolating at least a portion of the data set group aligned by the alignment unit 232C. The correction unit 232 generates a new data set group by replacing at least part of the data set group obtained by performing OCT with the interpolated data set calculated by the interpolation unit 232D.

FIG. 12 shows an explanatory diagram of the operation of the correction unit 232 according to the third operation example of the embodiment. FIG. 12 schematically represents a graph of deflection angle versus time characteristics according to the embodiment. In FIG. 12, parts similar to those in FIG. 5 are designated by the same reference numerals, and descriptions thereof will be omitted as appropriate. Further, although FIG. 12 schematically represents the operation of the interpolation process of the data set of A-line reflection intensity profile data, the operation of the interpolation process of the data set of A-scan image data is also similar.

The alignment unit 232C selects two data sets so that the deflection angles are equally spaced in the nonlinear operation range R1 or R2 in the deflection angle vs. time characteristic of the optical scanner 42, and adjusts the depth of the selected two data sets. Identify a predetermined range of directions. In some embodiments, the alignment unit 232C specifies a range in the depth direction corresponding to a predetermined layer region by segmentation processing. The alignment unit 232C specifies the range in the depth direction for the two data sets in the nonlinear operation range R1 or R2, and specifies the z position of the interpolated data set so that the deflection angles are equally spaced. The alignment unit 232C aligns the two data sets in the nonlinear operation range R1 or R2 to the specified z position.

The interpolation unit 232D calculates an interpolated data set by interpolating the two data sets aligned by the alignment unit 232C in the specified range in the depth direction. At this time, the interpolation unit 232D calculates the interpolated data set by linear interpolation processing, averaging processing, or weighted averaging processing.

(Fourth operation example)
FIG. 13 shows a block diagram of a configuration example of the correction unit 232 according to the fourth operation example of the embodiment.

The correction section 232 includes an addition section 232E. The adding unit 232E generates a new data set so that the deflection angles are equally spaced. In some embodiments, the adder 232E adds a data set corresponding to deflection angles in the linear operating range R0 in the deflection angle vs. time characteristic of the optical scanner 42. In some embodiments, the adder 232E replicates adjacent A-line data sets. That is, the addition unit 232E adds a data set based on the data set corresponding to the deflection angle in the linear motion range R0.

FIG. 14 shows an explanatory diagram of the operation of the correction unit 232 according to the fourth operation example of the embodiment. In FIG. 14, parts similar to those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The adding unit 232E adds data sets corresponding to the deflection angles in the linear operation range R0 so that the deflection angles are at equal intervals. In some embodiments, the correction unit 232 thins out the data set corresponding to the deflection angles in the nonlinear operating range R1 or R2 so that the deflection angles are equally spaced.

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

(user interface)
User interface 240 includes a display section 240A and an operation section 240B. The display section 240A includes the display device of the arithmetic and control unit 200 and the display device 3 described above. The operation section 240B is configured to include the operation device of the arithmetic and control unit 200 described above. The operation unit 240B may include various buttons and keys provided on the housing or outside of the ophthalmologic apparatus 1. For example, when the fundus camera unit 2 has a housing similar to a conventional fundus camera, the operation section 240B may include a joystick, an operation panel, etc. provided in this housing. Further, the display section 240A may include various display devices such as a touch panel provided on the housing of the fundus camera unit 2.

Note that the display section 240A and the operation section 240B do not need to be configured as separate devices. For example, it is also possible to use a device such as a touch panel that has a display function and an operation function integrated. In that case, the operation unit 240B is configured to include this touch panel and a computer program. The content of the operation on the operation unit 240B is input to the control unit 210 as an electrical signal. Further, operations and information input may be performed using a graphical user interface (GUI) displayed on the display section 240A and the operation section 240B.

The optical system in the path from the interference optical system to the objective lens 22 included in the OCT unit 100, or these optical systems and the image forming section 231, is an example of the "data acquisition section" according to the embodiment.

[motion]
The operation of the ophthalmologic apparatus 1 according to the embodiment will be described.

In the first operation example, a dataset group of A-scan image data is corrected.

FIG. 15 shows a first operation example of the ophthalmologic apparatus 1 according to the embodiment. FIG. 15 shows a flowchart of a first operation example of the ophthalmologic apparatus 1 according to the embodiment. The storage unit 212 stores a computer program for implementing the processing shown in FIG. 15. The main control unit 211 executes the processing shown in FIG. 15 by operating according to this computer program.

(S1: Alignment)
The main control unit 211 executes alignment.

That is, the main control unit 211 controls the alignment optical system 50 to project the alignment index onto the eye E to be examined. At this time, a fixation target by the LCD 39 is also projected onto the eye E to be examined. The main control unit 211 controls the moving mechanism 150 based on the amount of movement of the optical system specified based on the received light image acquired by the image sensor 35, for example, and moves the optical system with respect to the eye E by the amount of movement. Move relatively. The main control unit 211 repeatedly executes this process.

In some embodiments, the above coarse alignment adjustment and fine alignment adjustment are performed after the alignment in step S1 is completed.

(S2: Obtain adjustment tomogram)
The main control unit 211 displays a fixation target for OCT measurement at a predetermined position on the LCD 39. The main control unit 211 can display a fixation target at a display position on the LCD 39 that corresponds to the position of the optical axis of the optical system in the fundus Ef.

Next, the main control unit 211 controls the OCT unit 100 to perform OCT provisional measurement and obtain an adjustment tomographic image for adjusting the reference position of the measurement range in the depth direction. Specifically, the main control unit 211 deflects the measurement light LS generated based on the light L0 emitted from the light source unit 101 by controlling the optical scanner 42, and causes the main control unit 211 to deflect the measurement light LS generated based on the light L0 emitted from the light source unit 101, and to A predetermined part (for example, the fundus of the eye) of the optometrist E is scanned. The detection results of the interference light obtained by scanning the measurement light LS are sampled in synchronization with the clock KC and then sent to the image forming section 231. The image forming unit 231 forms a tomographic image (OCT image) of the eye E from the obtained interference signal.

(S3: Adjust the reference position in the depth direction)
Next, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction).

For example, the main control unit 211 causes the data processing unit 230 to specify a predetermined region (for example, the sclera) in the tomographic image obtained in step S2, and A position separated by a predetermined distance is set as a reference position of the measurement range. Further, a predetermined position determined in advance so that the optical path lengths of the measurement light LS and the reference light LR substantially match may be set as the reference position of the measurement range.

(S4: Focus adjustment, polarization adjustment)
Next, the main control unit 211 executes focus adjustment control and polarization adjustment control.

For example, the main control unit 211 controls the focusing drive unit 43A to move the OCT focusing lens 43 by a predetermined distance, and then controls the OCT unit 100 to perform OCT measurement. As described above, the main control unit 211 causes the data processing unit 230 to determine the focus state of the measurement light LS based on the detection result of the interference light obtained by OCT measurement. When it is determined that the focus state of the measurement light LS is not appropriate based on the determination result by the data processing unit 230, the main control unit 211 controls the focus drive unit 43A again and determines that the focus state is appropriate. Repeat until determined.

For example, the main controller 211 controls at least one of the polarization controllers 103 and 118 to change the polarization state of at least one of the light L0 and the measurement light LS by a predetermined amount, and then controls the OCT unit 100. The image forming section 231 causes the image forming section 231 to perform OCT measurement and form an OCT image based on the detection result of the acquired interference light. As described above, the main control unit 211 causes the data processing unit 230 to determine the image quality of the OCT image obtained by OCT measurement. When it is determined that the polarization state of the measurement light LS is not appropriate based on the determination result by the data processing unit 230, the main control unit 211 controls the polarization controllers 103 and 118 again to ensure that the polarization state is appropriate. Repeat until it is determined that

(S5: Obtain interference signal)
Next, the main controller 211 controls the OCT unit 100 to perform OCT measurement. The detection result of the interference light obtained by the OCT measurement is sampled in the DAQ 130 and stored in the storage unit 212 or the like as an interference signal.

(S6: Form a tomographic image)
Next, the main control unit 211 causes the image forming unit 231 to form a dataset group of A-scan image data of the eye E based on the interference signal acquired in step S5.

(S7: Correct tomographic image)
The main control unit 211 causes the correction unit 232 to correct at least a part of the data set group of A-scan image data formed in step S6, based on the correction data 212A stored in the storage unit 212. A data set group of scan image data is generated. The main control unit 211 can display a B-scan image (tomographic image IMG1 in FIG. 6) on the display unit 240A based on the newly generated dataset group of A-scan image data.

This is the end of the operation of the ophthalmologic apparatus 1 (END).

In the second operation example, a data set group of reflection intensity profile data is corrected.

FIG. 16 shows a second operation example of the ophthalmologic apparatus 1 according to the embodiment. FIG. 16 represents a flowchart of a second operation example of the ophthalmologic apparatus 1 according to the embodiment. A computer program for implementing the process shown in FIG. 16 is stored in the storage unit 212. The main control unit 211 executes the processing shown in FIG. 16 by operating according to this computer program.

(S11: Alignment)
The main control unit 211 executes alignment similarly to step S1.

(S12: Obtain adjustment tomographic image)
As in step S2, the main control unit 211 controls the OCT unit 100 to perform OCT provisional measurement and obtain an adjustment tomographic image for adjusting the reference position of the measurement range in the depth direction.

(S13: Adjust the reference position in the depth direction)
Subsequently, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction) similarly to step S3.

(S14: Focus adjustment, polarization adjustment)
Next, the main control unit 211 executes focus adjustment control and polarization adjustment control similarly to step S4.

(S15: Obtain interference signal)
Next, the main control unit 211 controls the OCT unit 100 to perform OCT measurement, similarly to step S5.

(S16: Correct data set group)
The main control unit 211 causes the correction unit 232 to correct at least a part of the data set group of reflection intensity profile data acquired in step S15 based on the correction data 212A stored in the storage unit 212. A dataset group of intensity profile data is generated.

(S17: Form a tomographic image)
Next, the main control unit 211 causes the image forming unit 231 to form a dataset group of A-scan image data of the eye E based on the new dataset group of reflection intensity profile data generated in step S16. The main control unit 211 can display a B-scan image (tomographic image IMG1 in FIG. 6) on the display unit 240A based on the dataset group of A-scan image data formed by the image forming unit 231.

This is the end of the operation of the ophthalmologic apparatus 1 (END).

<Modified example>
In the above embodiment, when the optical scanner 42 includes a first galvano scanner and a second galvano scanner, the storage unit 212 may store correction data for each galvano scanner. Below, the configuration of an ophthalmologic apparatus according to a modification of the embodiment will be described, focusing on the differences from the configuration of the ophthalmologic apparatus 1 according to the embodiment.

FIG. 17 shows a block diagram of a configuration example of an ophthalmologic apparatus according to a modification of the embodiment. In FIG. 17, parts similar to those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The configuration of the ophthalmologic apparatus according to the modified example of the embodiment differs from the configuration of the ophthalmologic apparatus 1 according to the embodiment shown in FIG. 3 in the correction data 212A stored in the storage unit 212. The correction data 212A includes first correction data 2121 and second correction data 2122.

The first correction data 2121 is correction data corresponding to the deflection angle versus time characteristic (operation characteristic) of the first galvano scanner. The second correction data 2122 is correction data corresponding to the deflection angle versus time characteristic (operation characteristic) of the second galvano scanner. The correction unit 232 can perform a correction process by switching between a correction process for at least a part of the data set group based on the first correction data 2121 and a correction process for at least a part of the data set group based on the second correction data 2122. be.

In OCT measurement, a measurement site is scanned in various scanning modes. Since the deflection angle range and deflection speed differ depending on the scanning area and scanning pattern, one of the first galvano scanner and the second galvano scanner is controlled to operate at high speed and the other at low speed depending on the scanning conditions. According to this modification, the data set group can be corrected for the nonlinear operation of either the first galvano scanner or the second galvano scanner depending on the scanning conditions, so the deflection speed can be adjusted in various scanning modes. This makes it possible to respond to faster speeds.

In addition, although the optical scanner 42 was comprised by the galvano scanner in the said embodiment or modification, the structure based on embodiment or its modification is not limited to this. For example, the optical scanner 42 may be configured with a resonant mirror.

[effect]
An ophthalmologic apparatus and a control method thereof according to an embodiment will be described.

The ophthalmological apparatus (1) according to some embodiments includes a data acquisition unit (an optical system in the path from the interference optical system included in the OCT unit 100 to the objective lens 22, or these optical systems and the image forming unit 231); It includes a storage section (212) and a correction section (232). The data acquisition unit includes an optical scanner (42) capable of deflecting light in a predetermined deflection angle range, and uses measurement light (LS) deflected in a predetermined deflection direction by the optical scanner to target the eye (E) to be examined. A first data set group in the A-scan direction is obtained by performing optical coherence tomography. The storage unit stores correction data (212A) corresponding to the operating characteristics (deflection angle vs. time characteristics) of the optical scanner. The correction unit generates a second data set group by correcting at least a portion of the first data set group based on the correction data stored in the storage unit.

According to such a configuration, at least a part of the first data set group in a plurality of A-scan directions acquired by performing OCT using an optical scanner is converted into correction data corresponding to the operating characteristics of the optical scanner. Since the second data set group is generated by performing correction based on this, it is possible to obtain a data set group in the A-scan direction that takes into account the operating characteristics of the optical scanner. For example, it becomes possible to generate a group of data sets at uniformly distributed scanning positions from a group of data sets acquired at unevenly distributed scanning positions due to the nonlinear operation of the optical scanner. Furthermore, for example, it is possible to generate a data set group in which only a desired region is acquired at high density from a data set group acquired by linear operation of an optical scanner. This makes it possible to use part of the nonlinear operating range of the optical scanner, making it possible to respond to faster deflection speeds of the optical scanner, and making it possible to perform wide-angle, highly accurate OCT measurements. become able to.

In the ophthalmological apparatus according to some embodiments, the correction unit is configured such that the first data set group is a data set group acquired based on measurement light deflected by an optical scanner at deflection angles at substantially equal intervals in a deflection angle range. One or more data sets corresponding to at least a part of the deflection angle range among the first data set group are corrected based on the correction data so that

According to such a configuration, it is possible to generate a data set group at evenly distributed scanning positions from a data set group acquired at unevenly distributed scanning positions due to the nonlinear operation of the optical scanner. Thereby, even when the deflection speed (scanning frequency) of the optical scanner is increased, it becomes possible to perform imaging using the nonlinear operating range, so that it becomes possible to cope with the increase in the deflection speed.

In the ophthalmological apparatus according to some embodiments, the optical scanner includes a mirror that reflects the measurement light, and reflects the measurement light in a deflection angle range by reciprocating the mirror in a swing direction corresponding to the deflection direction. and at least part of the deflection angle range is a first deflection angle (rs) at which the mirror starts swinging in the swing direction or a second deflection angle (rs) at which the mirror ends swinging in the swing direction. Contains (re).

According to such a configuration, it becomes possible to perform imaging using the nonlinear operating range of an optical scanner such as a galvano scanner, so it becomes possible to cope with an increase in the deflection speed.

In the ophthalmological apparatus according to some embodiments, the correction unit includes an extraction unit (232A) that extracts one or more data sets from at least part of the first data set group, and the correction unit includes an extraction unit (232A) that extracts one or more data sets from at least a part of the first data set group; Replace with one or more datasets.

With this configuration, it becomes possible to perform imaging using the nonlinear operating range of the optical scanner with a simple extraction process for a group of data sets, making it possible to respond to higher deflection speeds. .

In the ophthalmological apparatus according to some embodiments, the correction unit includes an interpolation unit (232B) that calculates an interpolated data set by interpolating at least a part of the first data set group, section is replaced with the interpolated data set calculated by the interpolation section.

With this configuration, it becomes possible to perform imaging using the nonlinear operating range of the optical scanner with simple interpolation processing for a group of data sets, making it possible to respond to faster deflection speeds. .

In the ophthalmological apparatus according to some embodiments, the correction unit includes an alignment unit (232C) that aligns at least a part of the first data set group in the A-scan direction, and alignment performed by the alignment unit. an interpolation unit (232D) that interpolates at least part of the first data set group to calculate an interpolated data set, and replaces at least part of the first data set group with the interpolated data set calculated by the interpolation unit. .

With this configuration, it is possible to perform imaging using the nonlinear operating range of the optical scanner through simple alignment processing and interpolation processing for a group of data sets, so it is possible to cope with higher deflection speeds. become able to.

In the ophthalmological apparatus according to some embodiments, the correction unit adds a new data set to the first data set group.

With this configuration, it becomes possible to perform imaging using the nonlinear operating range of the optical scanner with simple additional processing of the data set group, making it possible to respond to higher deflection speeds. .

In the ophthalmological apparatus according to some embodiments, the new data set is generated based at least in part on the first set of data sets.

According to this configuration, a new data set is obtained based on at least a part of the first data set group, and the obtained new data set is added. Additional processing can be performed.

In the ophthalmological apparatus according to some embodiments, the optical scanner includes a first scanner (first galvano scanner) that deflects measurement light in a first deflection direction in a first deflection angle range, and a measurement light deflected by the first scanner. a second scanner (second galvano scanner) that deflects light toward the subject's eye in a second deflection direction and in a second deflection angle range, and the correction unit performs a first correction corresponding to the operating characteristics of the first scanner. Correction processing for at least part of the first data set group based on the data (2121), and correction processing for at least part of the first data set group based on the second correction data (2122) corresponding to the operating characteristics of the second scanner. It can be executed by switching between the two.

According to such a configuration, the data set group can be corrected for nonlinear operation of either the first scanner or the second scanner depending on the scanning conditions, so that OCT performed in various scanning modes can be corrected. It becomes possible to cope with an increase in the deflection speed in measurement.

In the ophthalmological apparatus according to some embodiments, the storage unit stores a plurality of correction data corresponding to a plurality of scan conditions in which at least one of a deflection angle range and a deflection speed of the optical scanner differs, and the correction unit At least a portion of the first data set group is corrected based on correction data stored in the storage unit corresponding to the correction data.

According to such a configuration, the second data set group can be generated by correcting at least a part of the first data set group based on the correction data corresponding to the scan conditions, so when the scan conditions are different, the second data set group can be generated. However, it becomes possible to obtain a dataset group that takes into account the operating characteristics of the optical scanner.

The ophthalmological apparatus according to some embodiments includes an image forming section (231) that forms a tomographic image of the eye to be examined based on the second data set group generated by the correction section.

According to such a configuration, a new data set group can be generated by correcting the data set group of reflection intensity profile data in the A-scan direction according to the operating characteristics of the optical scanner.

Some embodiments are methods of controlling an ophthalmological apparatus (1) including an optical scanner (42) capable of deflecting light in a predetermined deflection angle range. The method for controlling an ophthalmologic apparatus includes a data acquisition step and a correction step. The data acquisition step includes a first data set group in the A scan direction by performing optical coherence tomography on the eye (E) using measurement light (LS) deflected in a predetermined deflection direction by an optical scanner. get. In the correction step, a second data set group is generated by correcting at least a portion of the first data set group based on correction data (212A) corresponding to the operating characteristics (deflection angle vs. time characteristics) of the optical scanner.

According to such a method, at least a part of the first data set group in a plurality of A-scan directions obtained by performing OCT using an optical scanner is converted into correction data corresponding to the operating characteristics of the optical scanner. Since the second data set group is generated by performing correction based on this, it is possible to obtain a data set group in the A-scan direction that takes into account the operating characteristics of the optical scanner. For example, it becomes possible to generate a group of data sets at uniformly distributed scanning positions from a group of data sets acquired at unevenly distributed scanning positions due to the nonlinear operation of the optical scanner. Furthermore, for example, it is possible to generate a data set group in which only a desired region is acquired at high density from a data set group acquired by linear operation of an optical scanner. This makes it possible to use part of the nonlinear operating range of the optical scanner, making it possible to respond to faster deflection speeds of the optical scanner, and making it possible to perform wide-angle, highly accurate OCT measurements. become able to.

In the method for controlling an ophthalmological apparatus according to some embodiments, the first data set group is data obtained based on measurement light deflected by an optical scanner at deflection angles at substantially equal intervals in a deflection angle range. One or more data sets corresponding to at least part of the deflection angle range of the first data set group are corrected based on the correction data so as to form a set group.

According to such a method, it is possible to generate a data set group at uniformly distributed scanning positions from a data set group acquired at unevenly distributed scanning positions due to the nonlinear operation of the optical scanner. Thereby, even when the deflection speed (scanning frequency) of the optical scanner is increased, it becomes possible to perform imaging using the nonlinear operating range, so that it becomes possible to cope with the increase in the deflection speed.

In the method for controlling an ophthalmological apparatus according to some embodiments, the optical scanner includes a mirror that reflects the measurement light, and the optical scanner reciprocates in a rocking direction corresponding to the deflection direction, thereby reciprocating the mirror in a deflection angle range. The measurement light is deflected, and at least a part of the deflection angle range is a first deflection angle (rs) at which the mirror starts to swing in the swing direction or a first deflection angle (rs) at which the mirror ends in the swing direction. 2 deflection angle (re).

According to such a method, it becomes possible to perform imaging using the nonlinear operating range of an optical scanner such as a galvano scanner, so that it becomes possible to cope with an increase in the deflection speed.

In the method for controlling an ophthalmological apparatus according to some embodiments, the optical scanner includes a first scanner (first galvano scanner) that deflects measurement light in a first deflection direction in a first deflection angle range; a second scanner (second galvano scanner) that deflects the measured measurement light toward the subject's eye in a second deflection direction and in a second deflection angle range, and the correction step corresponds to the operating characteristics of the first scanner. Correction processing for at least part of the first data set group based on first correction data (2121), and at least part of the first data set group based on second correction data (2122) corresponding to the operating characteristics of the second scanner. It is possible to execute the correction process by switching between the two.

According to such a method, the data set group can be corrected for nonlinear operation of either the first scanner or the second scanner depending on the scanning conditions, so OCT performed in various scanning modes can be corrected. It becomes possible to cope with an increase in the deflection speed in measurement.

A method for controlling an ophthalmological apparatus according to some embodiments includes an image forming step of forming a tomographic image of the eye to be examined based on the second data set group generated in the correction step.

According to such a method, a new data set group can be generated by correcting the data set group of reflection intensity profile data in the A-scan direction according to the operating characteristics of the optical scanner.

<Others>
The embodiment shown above or its modification example is only an example for implementing the present invention. Those who wish to implement this invention can make arbitrary modifications, omissions, additions, etc. within the scope of the gist of this invention.

In some embodiments, a program is provided for causing a computer to execute the method for controlling an ophthalmological apparatus described above. Such a program can be stored in any computer-readable recording medium. Examples of this recording medium include semiconductor memory, optical disks, magneto-optical disks (CD-ROM/DVD-RAM/DVD-ROM/MO, etc.), magnetic storage media (hard disks/floppy (registered trademark) disks/ZIP, etc.), etc. It is possible to use It is also possible to send and receive this program via a network such as the Internet or LAN.

1 Ophthalmological apparatus 2 Fundus camera unit 42 Optical scanner 100 OCT unit 200 Arithmetic control unit 210 Control section 211 Main control section 212 Storage section 212A Correction data 230 Data processing section 231 Image forming section 232 Correction section E Eye to be examined LS Measuring light

Claims (10)

The method includes an optical scanner capable of deflecting light in a predetermined deflection angle range including a linear operation range and a nonlinear operation range, and performs optical coherence on the eye to be examined using measurement light deflected in a predetermined deflection direction by the optical scanner. a data acquisition unit that acquires a first data set group in the A-scan direction by executing tomography;
a storage unit that stores a plurality of correction data of the nonlinear operation range corresponding to a plurality of scan conditions in which at least one of a deflection angle range and a deflection speed of the optical scanner is different;
Correcting at least a portion of the first data set group based on any of the plurality of correction data corresponding to scan conditions of the optical scanner so as to cancel uneven distribution of scanning positions by the measurement light. a correction unit that generates two data set groups;
Ophthalmic equipment, including. a first optical scanner capable of deflecting light in a first deflection angle range including a linear operating range and a nonlinear operating range; and a second optical scanner capable of deflecting light in a second deflection angle range including a linear operating range and a nonlinear operating range. an optical scanner, and performs optical coherence tomography on the subject's eye using measurement light deflected in a predetermined deflection direction by the first optical scanner and the second optical scanner. a data acquisition unit that acquires one data set group;
a storage unit that stores first correction data corresponding to a nonlinear operation range of the first deflection angle range and second correction data corresponding to a nonlinear operation range of the second deflection angle range;
A second data set group is generated by correcting at least a portion of the first data set group based on the first correction data or the second correction data so as to cancel uneven distribution of scanning positions by the measurement light. a correction section to
Ophthalmic equipment, including. The storage unit stores a plurality of first correction data of the nonlinear operation range corresponding to a plurality of scan conditions in which at least one of the first deflection angle range and deflection speed of the first optical scanner is different, and the second optical scanner. a plurality of second correction data of the nonlinear operation range corresponding to a plurality of scan conditions in which at least one of the second deflection angle range and the deflection speed is different;
The correction unit is configured to correct any one of the plurality of first correction data corresponding to the scan conditions of the first optical scanner, or one of the plurality of second correction data corresponding to the scan conditions of the second optical scanner. The ophthalmologic apparatus according to claim 2, wherein the second data set group is generated based on the ophthalmological apparatus. The correction unit is
Two data sets of the first data set group are selected so that the deflection angles are at equal intervals in the nonlinear operation range, a predetermined range in the A-scan direction is specified for the selected two data sets, and the deflection angle is an alignment unit that specifies the positions of the interpolated data sets in the A-scan direction so that they are equally spaced, and aligns the two selected data sets to the specified positions;
an interpolation unit that calculates an interpolated data set by interpolating the two data sets aligned by the alignment unit;
The ophthalmologic apparatus according to any one of claims 1 to 3, further comprising: replacing the selected two data sets with an interpolated data set calculated by the interpolation unit. 5. The image forming apparatus according to any one of claims 1 to 4, further comprising an image forming section that forms a tomographic image of the eye to be examined based on the second data set group generated by the correction section. Ophthalmology equipment. A method for controlling an ophthalmological device including an optical scanner capable of deflecting light in a predetermined deflection angle range including a linear operating range and a non-linear operating range, the method comprising:
a data acquisition step of acquiring a first data set group in the A-scan direction by performing optical coherence tomography on the eye to be examined using measurement light deflected in a predetermined deflection direction by the optical scanner;
Any one of the plurality of correction data corresponding to the scanning condition of the optical scanner, among the plurality of correction data of the nonlinear operation range corresponding to a plurality of scanning conditions in which at least one of the deflection angle range and the deflection speed of the optical scanner is different. a correction step of generating a second data set group by correcting at least a part of the first data set group so as to cancel the uneven distribution of scanning positions by the measurement light;
A method of controlling an ophthalmological device, including: a first optical scanner capable of deflecting light in a first deflection angle range including a linear operating range and a nonlinear operating range; and a second optical scanner capable of deflecting light in a second deflection angle range including a linear operating range and a nonlinear operating range. 1. A method of controlling an ophthalmological device including an optical scanner,
Obtaining a first data set group in the A-scan direction by performing optical coherence tomography on the eye to be examined using measurement light deflected in a predetermined deflection direction by the first optical scanner and the second optical scanner. a data acquisition step;
Cancel the uneven distribution of scanning positions by the measurement light based on first correction data corresponding to a nonlinear operation range of the first deflection angle range or second correction data corresponding to the nonlinear operation range of the second deflection angle range. a correction step of generating a second data set group by correcting at least a portion of the first data set group so as to
A method of controlling an ophthalmological device, including: The ophthalmological apparatus includes a plurality of first correction data of the nonlinear operation range corresponding to a plurality of scan conditions in which at least one of the first deflection angle range and deflection speed of the first optical scanner is different, and the second optical scanner. a plurality of second correction data of the nonlinear operation range corresponding to a plurality of scan conditions in which at least one of the second deflection angle range and the deflection speed is different;
In the correction step, one of the plurality of first correction data corresponding to the scan conditions of the first optical scanner or one of the plurality of second correction data corresponding to the scan conditions of the second optical scanner. The method of controlling an ophthalmological apparatus according to claim 7, further comprising generating the second data set group based on the ophthalmological apparatus. The correction step includes:
Two data sets of the first data set group are selected so that the deflection angles are at equal intervals in the nonlinear operation range, a predetermined range in the A-scan direction is specified for the selected two data sets, and the deflection angle is an alignment step of identifying the positions of the interpolated data sets in the A-scan direction so that they are equally spaced, and aligning the two selected data sets to the identified positions;
an interpolation step of calculating an interpolated data set by interpolating the two data sets aligned in the alignment step;
The method for controlling an ophthalmological apparatus according to any one of claims 6 to 8, comprising: replacing the selected two data sets with an interpolated data set calculated in the interpolation step. The method according to any one of claims 6 to 9, further comprising an image forming step of forming a tomographic image of the eye to be examined based on the second data set group generated in the correction step. A method of controlling an ophthalmological device.

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