Optical coherence tomography device, control method therefor, and program

Abstract

An optical coherence tomography apparatus includes an optical system, a storage unit, and a control unit. The optical system is configured so as to be capable of changing optical conditions, and is configured so as to acquire optical coherence tomography data of an object to be measured by scanning the object with measurement light. The storage unit stores, in advance, setting information for setting the optical conditions of the optical system such that the image quality of an image formed on the basis of the optical coherence tomography data is equal to or greater than a predetermined image quality level for each scanning region in the object to be measured. The control unit changes the optical conditions of the optical system on the basis of the setting information in accordance with the scanning region of the measurement light in the object to be measured, and performs optical coherence tomography on the object to be measured.

Description

Technical Field

[0001] This invention relates to an optical coherence tomography (OCT) device, a control method for the OCT device, and a program thereof. Background Technology

[0002] Optical coherence tomography (OCT) devices are known to use light beams from sources such as lasers to form images representing the surface and internal morphology of the object being measured. Since OCT is non-invasive and can be performed on biological organisms, its applications in the medical and biological fields are highly anticipated. For example, in ophthalmology, devices for forming images of the fundus and cornea are already in practical use. Devices employing such OCT methods (OCT devices) can be used for observation of various parts of the examined eye. Furthermore, due to the ability to acquire high-resolution images, they are used for the diagnosis of various ophthalmic diseases.

[0003] When photographing an object with a wide angle, the optimal optical conditions for the optical system used in each scanning area vary depending on the cross-sectional shape of the object. As a result, the image quality (measurement accuracy) differs for each scanning area. Therefore, sometimes the image quality around the area of ​​interest is insufficient, requiring a re-photograph of the object.

[0004] For example, Patent Document 1 discloses a method for synthesizing multiple two-dimensional images obtained by scanning different positions within a predetermined imaging range of the eye being examined at intervals to obtain a two-dimensional image within the predetermined imaging range of the eye being examined.

[0005] Patent document: Japanese Patent Application Publication No. 2022-69735 Summary of the Invention However, even using the method disclosed in Patent Document 1, it is impossible to avoid the need for re-shooting due to differences in image quality in each scanned area. Therefore, with each re-shoot, the shooting time increases, and when the object being measured is a living eye, there is an increased burden on the subject.

[0006] The present invention was made in view of the following circumstances, and one of its objectives is to provide a new technique for obtaining an image of the object being measured with good image quality while avoiding reshooting as much as possible when shooting the object with a wide angle.

[0007] One embodiment is an optical coherence tomography (OCT) apparatus, comprising: an optical system configured to change optical conditions and configured to acquire OCT data of a test object by scanning the test object with a measurement light; a storage unit that pre-stores setting information for setting the optical conditions of the optical system according to each scanning area in the test object such that the image quality formed based on the OCT data is at or above a predetermined image quality level; and a control unit that performs OCT scanning of the test object by changing the optical conditions of the optical system based on the setting information according to the scanning area of ​​the measurement light in the test object.

[0008] Another embodiment is a control method for an optical coherence tomography (OCT) apparatus, the OCT apparatus including an optical system configured to change optical conditions and to acquire OCT data of a test object by scanning the test object with a measurement light. The control method includes a control step in which the optical conditions of the optical system are changed based on setting information according to the scanning area of ​​the measurement light in the test object to perform an OCT scan of the test object. The setting information is used to set the optical conditions of the optical system for each scanning area in the test object such that the image quality formed based on the OCT data is at or above a predetermined quality level.

[0009] Another embodiment is a program that causes a computer to execute the steps of the control method for the optical coherence tomography apparatus described above.

[0010] Another embodiment is a computer program product, including a computer program / instructions. When the computer program product is executed by a processor, it implements the steps of the control method for the optical coherence tomography (OCT) device described above.

[0011] Another embodiment is a computer-readable storage medium (recording medium) storing a computer program / instructions. When the computer-readable storage medium is executed by a processor, it implements the steps of the control method for the optical coherence tomography (OCT) apparatus described above.

[0012] According to embodiments of the present invention, a new technique can be provided for obtaining an image of the object being measured with good image quality while minimizing reshoots when shooting the object with a wide-angle lens. Attached Figure Description

[0013] Figure 1This is a schematic diagram illustrating an example of the optical system structure of the ophthalmic device according to the first embodiment.

[0014] Figure 2 This is a schematic diagram illustrating an example of the optical system structure of the ophthalmic device according to the first embodiment.

[0015] Figure 3 This is a schematic diagram illustrating an example of the optical system structure of the ophthalmic device according to the first embodiment.

[0016] Figure 4 This is a schematic diagram illustrating an example of the processing system structure of the ophthalmic device according to the first embodiment.

[0017] Figure 5 This is a schematic diagram illustrating an example of the processing system structure of the ophthalmic device according to the first embodiment.

[0018] Figure 6 This is a diagram illustrating the operation of the ophthalmic device according to the first embodiment.

[0019] Figure 7 This is a diagram illustrating the operation of the ophthalmic device according to the first embodiment.

[0020] Figure 8 This is a flowchart illustrating an example of the operation of the ophthalmic device according to the first embodiment.

[0021] Figure 9 This is a diagram illustrating the operation of the ophthalmic device according to the first embodiment.

[0022] Figure 10 This is a diagram illustrating the operation of the ophthalmic device according to the first embodiment.

[0023] Figure 11 This is a diagram illustrating the operation of the ophthalmic device according to the first embodiment.

[0024] Figure 12 This is a flowchart illustrating an example of the operation of the ophthalmic device according to the first embodiment.

[0025] Figure 13 This is a flowchart illustrating an example of the operation of the ophthalmic device according to the first embodiment.

[0026] Figure 14 This is a schematic diagram illustrating an example of the optical system structure of the ophthalmic device according to the second embodiment.

[0027] Figure 15 This is a schematic diagram illustrating an example of the processing system structure of the ophthalmic device according to the second embodiment.

[0028] Figure 16 This is a schematic diagram illustrating an example of the processing system structure of the ophthalmic device according to the third embodiment.

[0029] Figure 17 This is a flowchart illustrating an example of the operation of the ophthalmic device according to the third embodiment.

[0030] Figure 18 This is a diagram illustrating the operation of the ophthalmic device according to the third embodiment. Detailed Implementation

[0031] Examples of embodiments of the optical coherence tomography (OCT) apparatus, its control method, and its procedure according to the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the contents of documents cited in this specification and any prior art can be incorporated into the following embodiments.

[0032] The optical coherence tomography (OCT) apparatus of the embodiment includes an optical system configured to modify optical conditions. The optical system includes an interferometric optical system configured to scan the object under test with measurement light to acquire OCT data of the object. The OCT apparatus pre-stores setting information for each of multiple scanning regions in the object under test, such that the image quality formed based on the OCT data is at or above a predetermined quality level. For example, the setting information is obtained through a prediction quantity. For example, in a formal measurement after the prediction quantity, the OCT apparatus modifies the optical conditions of the optical system based on the pre-stored setting information, according to the scanning region of the measurement light in the object under test, and performs OCT on the object under test.

[0033] Examples of optical conditions for an optical system include the focus position of the measurement light used in OCT, the polarization component of the measurement light, the aberration correction component, the difference in optical path length between the measurement light and the reference light, and the position of the optical system relative to the object being measured.

[0034] For example, the optical system includes one or more optical elements and is configured such that by controlling one or more optical elements, any one of the following can be changed: the focus position of the measurement light used for OCT, the polarization component of the measurement light, the aberration correction component, and the difference in optical path length between the measurement light and the reference light.

[0035] For example, the optical system includes a mechanism for moving an optical system or one or more optical elements, and is configured such that, through a control mechanism, any one of the following can be changed: the focus position of the measurement light used for OCT, the polarization component of the measurement light, the aberration correction component, and the difference in optical path length between the measurement light and the reference light.

[0036] For example, an OCT device includes a moving mechanism that moves an optical system relative to the object being measured, and is configured such that the position of the optical system relative to the object being measured can be changed by controlling the moving mechanism.

[0037] The focus position is changed by a focus position changing component, which is an optical element. Examples of focus position changing components include lenses that can move along the optical axis, liquid crystal lenses, Alvarez lenses, etc.

[0038] The polarization component is changed by a polarization component changing component, which is an optical element. Examples of polarization components include a polarization controller. When light from a light source is split into a measurement light and a reference light for OCT, the polarization controller can change the polarization component of either the light from the light source or the measurement light.

[0039] The aberration correction component is changed by the aberration correction device, which is an optical element. Examples of aberration correction devices include a variable cross cylinder (VCC) lens, a liquid crystal lens, a wavefront aberration correction optical system including a deformable mirror, and an Alvarez lens.

[0040] The difference in optical path length is changed by an optical path length changing component, which is an optical element or mechanism. Examples of optical path length changing components include those that change at least one of the optical path length of the measuring light and the optical path length of the reference light.

[0041] The position of the optical system relative to the object being measured is changed by a mechanism that alters at least one of the object being measured and the optical system. Examples of such mechanisms include a moving mechanism that changes the relative position of the object being measured and a holding member that maintains the optical system.

[0042] In examples of image quality exceeding a predetermined quality level, the highest image quality evaluation value is achieved when the overall image quality evaluation value is above a predetermined threshold level; the highest image quality is achieved when the overall image quality evaluation value is above a predetermined threshold level; the highest image quality is achieved when the statistical value of the image quality evaluation values ​​of multiple images calculated for each scan area is above a predetermined threshold level; and so on. Among these, the statistical values ​​include maximum, minimum, median, mean, mode, range, variance, standard deviation, a weighted average with a larger weighting coefficient closer to the area of ​​interest (optical axis of the optical system), or a value using a predetermined evaluation formula employing any of the above statistical values.

[0043] The optical conditions of such an optical system are set in, for example, predictions (pre-shooting, pre-scanning) performed before the formal measurement (formal imaging, formal scanning). In the formal measurement, OCT is performed on the object being measured by an optical system whose optical conditions are changed based on the setting information determined in the predictions.

[0044] Therefore, regardless of the cross-sectional shape of the object being measured, images of the object can be acquired with good image quality without the need for repeated formal measurements, thus shortening measurement time (image capture time). In particular, when the object being measured is a living eye, it reduces the burden on the subject. In some implementations, image quality can be confirmed (estimated) before performing the formal measurement.

[0045] In some embodiments, the scanning area includes: a central region of the object being measured, including the optical axis of the optical system; and one or more peripheral regions surrounding the central region. For example, one or more peripheral regions include: one or more intermediate regions disposed outside the central region and surrounding the central region; and a peripheral region disposed outside the outermost intermediate region of the one or more intermediate regions and surrounding the outermost intermediate region.

[0046] Therefore, even when the inclination of the cross section differs in the central region and one or more peripheral regions of the object being measured, images of the object being measured can be acquired with good image quality.

[0047] The control method of the OCT device in the embodiment is a method for controlling the OCT device of the embodiment. The control method of the OCT device in the embodiment includes one or more steps executed by the OCT device. The program (computer program) / instructions of the embodiment cause a computer to execute each step of the control method of the OCT device of the embodiment. The computer program product of the embodiment includes a computer program / instructions. When the computer program / instructions are executed by a processor, the computer program product implements each step of the control method of the OCT device of the embodiment. The recording medium (storage medium) of the embodiment is any computer-readable, non-transitory recording medium that records (stores) the program of the embodiment. The computer-readable storage medium of the embodiment stores the computer program / instructions. When the computer-readable storage medium is executed by a processor, the computer-readable storage medium implements each step of the control method of the OCT device of the embodiment. The recording medium can be an electronic medium utilizing magnetism, light, optomagnetism, semiconductors, etc. Typically, the recording medium is magnetic tape, magnetic disk, optical disk, optical disk, flash memory, solid-state drive, etc. Alternatively, the program can be transmitted and received via a network such as the Internet or LAN.

[0048] Hereinafter, an ophthalmic device that uses a living eye as the object of measurement will be described as an example of an OCT device as an embodiment. However, the embodiment can also be applied to OCT devices that use objects other than a living eye as the object of measurement.

[0049] The ophthalmic device described in this embodiment can perform OCT on any part of the examined eye, such as the fundus or anterior eye. In this specification, images acquired by OCT are sometimes collectively referred to as OCT images. In addition, the measurement work used to form OCT images is sometimes referred to as OCT measurement (formal measurement, predictive measurement).

[0050] Hereinafter, in the embodiments, the use of OCT methods with a swept-frequency source type in OCT measurements or imaging will be described in particular detail. However, the structure of the embodiments can also be applied to ophthalmic devices using other types of OCT (e.g., spectral domain type or time domain type).

[0051] Furthermore, the following explanation of image quality ratings clarifies the situation where higher image quality results in a higher rating and lower image quality results in a lower rating. However, the implementation method can also be applied to situations where higher image quality results in a lower rating and lower image quality results in a higher rating. In this case, in the following explanation, "high rating" should be replaced with "low rating," "rating value above the threshold" should be replaced with "rating value below the threshold," and "rating value less than the threshold" should be replaced with "rating value exceeding the threshold."

[0052] <First Implementation> [structure] like Figures 1-3 As shown, the ophthalmic device 1 of the first embodiment includes a fundus camera unit 2, an OCT unit 100, and a computation control unit 200. The fundus camera unit 2 has an optical system that is substantially the same as that of a conventional fundus camera. The OCT unit 100 is provided with an optical system for acquiring OCT images (e.g., tomographic images) of the fundus (or anterior eye). The computation control unit 200 includes a computer that performs various computational processing, control processing, etc.

[0053] [Fundus camera unit 2] exist Figure 1 The fundus camera unit 2 shown is equipped with an optical system for acquiring a two-dimensional image (fundus image) representing the surface morphology of the fundus Ef of the examined eye E. Fundus images include observation images, captured images, etc. Observation images are, for example, monochrome video images formed using near-infrared light at a predetermined frame rate. Captured images can be, for example, color images obtained by flash emission of visible light or monochrome static images using near-infrared or visible light as illumination. The fundus camera unit 2 may also be configured to acquire images other than these, such as sodium fluorescein fluorescence images, indocyanine green fluorescence images, autofluorescence images, etc.

[0054] The fundus camera unit 2 is equipped with a jaw rest and a forehead protector to support the subject's face. Furthermore, the fundus camera unit 2 includes an illumination optical system 10 and an imaging optical system 30. The illumination optical system 10 illuminates the fundus (Ef) with light. The imaging optical system 30 guides the fundus-reflected light of this illumination to the imaging device (CCD image sensor (sometimes simply referred to as CCD) 35, 38). Additionally, the imaging optical system 30 guides measurement light from the OCT unit 100 to the fundus (Ef) and guides the measurement light that has passed through the fundus (Ef) to the OCT unit 100.

[0055] The observation light source 11 of the illumination optical system 10 includes, for example, a halogen lamp. Light output from the observation light source 11 (observation illumination light) is reflected by a mirror 12 with a curved reflective surface, passes through a condenser lens 13, and becomes near-infrared light after passing through a visible light cutoff filter 14. Furthermore, the observation illumination light temporarily converges near the imaging light source 15, is reflected by a mirror 16, and passes through relay lenses 17 and 18, an aperture 19, and a relay lens 20. Then, the observation illumination light is reflected by the peripheral portion (the area around the aperture) of the aperture lens 21, passes through a dichroic mirror 48, and is refracted by the objective lens 22 to illuminate the fundus (Ef). Alternatively, an LED (Light Emitting Diode) can also be used as the observation light source.

[0056] The fundus reflected light from the illumination is refracted by objective lens 22, passes through dichroic mirror 48, passes through the aperture formed in the central region of aperture lens 21, passes through dichroic mirror 55, passes through focusing lens 31, and is reflected by mirror 32. Furthermore, this fundus reflected light passes through semi-reflective mirror 33A, is reflected by dichroic mirror 33, and is imaged onto the light-receiving surface of CCD image sensor 35 by condenser lens 34. CCD image sensor 35 detects fundus reflected light, for example, at a predetermined frame rate. An image (observation image) based on the fundus reflected light detected by CCD image sensor 35 is displayed on display device 3. Additionally, when the focus of imaging optical system 30 is aligned with the anterior eye, an observation image of the anterior eye of the examined eye E is displayed.

[0057] The imaging light source 15 includes, for example, a xenon lamp. Light output from the imaging light source 15 (imaging illumination light) illuminates the fundus Ef through the same path as the observation illumination light. The fundus-reflected light from the imaging illumination light is guided to a dichroic mirror 33 through the same path as the observation illumination light, passes through the dichroic mirror 33, is reflected by a reflecting mirror 36, and is imaged onto the light-receiving surface of a CCD image sensor 38 by a condenser lens 37. An image (imported image) based on the fundus-reflected light detected by the CCD image sensor 38 is displayed on the display device 3. Furthermore, the display device 3 displaying the observation image and the display device 3 displaying the captured image can be the same device or different devices. Additionally, when the same imaging is performed with infrared light illuminating the examined eye E, an infrared captured image is displayed. Alternatively, an LED can also be used as the imaging light source.

[0058] The LCD (Liquid Crystal Display) 39 displays fixation targets and visual acuity testing targets. Fixation targets are used to cause the tested eye E to fixate, and are used in fundus photography and OCT measurements.

[0059] A portion of the light output from LCD39 is reflected by semi-reflective mirror 33A and then by reflective mirror 32. It then passes through focusing lens 31 and dichroic mirror 55, and through the aperture of aperture lens 21. The light passing through the aperture is then refracted by dichroic mirror 48, refracted by objective lens 22, and projected onto the fundus Ef.

[0060] By changing the display position of the fixation target on the LCD39 screen, the fixation position of the examined eye E can be changed. The fixation position of the examined eye E may include, for example, a position for acquiring an image centered on the macula of the fundus Ef, a position for acquiring an image centered on the optic nerve head, or a position for acquiring an image centered on the center of the fundus between the macula and the optic nerve head. Furthermore, the display position of the fixation target can be changed arbitrarily.

[0061] Furthermore, similar to conventional fundus cameras, the fundus camera unit 2 is equipped with an alignment optical system 50 and a focusing optical system 60. The alignment optical system 50 generates a target (alignment target) for aligning the device optical system with respect to the examined eye E. The focusing optical system 60 generates a target (split-image target) for focusing with respect to the fundus Ef.

[0062] The light (alignment light) output from LED51 of the alignment optical system 50 passes through apertures 52 and 53 and relay lens 54, is reflected by dichroic mirror 55, and passes through the aperture of aperture lens 21. The light passing through the aperture passes through dichroic mirror 48 and is projected onto the cornea of ​​the eye being examined, E, by objective lens 22.

[0063] The corneal reflected light from the alignment light passes through the objective lens 22, the dichroic mirror 48, and the aforementioned aperture. A portion of it passes through the dichroic mirror 55, then through the focusing lens 31, is reflected by the reflecting mirror 32, and passes through the semi-reflective mirror 33A. The corneal reflected light that has passed through the semi-reflective mirror 33A is reflected by the dichroic mirror 33 and projected by the condenser lens 34 onto the light-receiving surface of the CCD image sensor 35. The light-receiving image (aligned target) based on the CCD image sensor 35 is displayed on the display device 3 along with the observed image. The user performs the same operation as with conventional fundus cameras to perform alignment. Alternatively, the arithmetic control unit 200 can analyze the position of the aligned target and move the optical system to perform alignment (automatic alignment function).

[0064] During focusing adjustment, the reflective surface of the reflector 67 is tilted and positioned in the optical path of the illumination optics system 10. The light (focused light) output from the LED 61 of the focusing optics system 60 passes through the relay lens 62, is split into two beams by the split-image target plate 63, passes through the two-aperture aperture 64, and is reflected by the reflector 65. The light reflected by the reflector 65 is temporarily imaged onto the reflective surface of the reflector 67 by the condenser lens 66 and then reflected. Subsequently, the focused light is reflected by the aperture lens 21 through the relay lens 20, passes through the dichroic mirror 48, is refracted by the objective lens 22, and projected onto the fundus Ef.

[0065] The fundus reflection of the focused light travels the same path as the corneal reflection of the aligned light and is detected by the CCD image sensor 35. The light-receiving image (split-image target) formed by the CCD image sensor 35 is displayed on the display device 3 along with the observed image. As before, the arithmetic control unit 200 analyzes the position of the split-image target and moves the focusing lens 31 and the focusing optical system 60 to perform focusing (autofocus function). Alternatively, focusing can be performed manually while visually confirming the split-image target.

[0066] The dichroic mirror 48 branches the optical path used for OCT measurement from the optical path used for fundus imaging. The dichroic mirror 48 reflects the light used for OCT measurement in the wavelength range, allowing the light used for fundus imaging to pass through. In the optical path used for OCT measurement, from the OCT unit 100 side, a collimating lens unit 40, an optical path length changing unit 41, an optical scanner 42, a collimating lens 43, a reflecting mirror 44, an OCT focusing lens 45, a field lens 46, and a VCC lens 47 are arranged sequentially.

[0067] The optical path length changing unit 41 is configured to be able to Figure 1 Moving the optical path in the direction of the arrow indicates changes the optical path length for OCT measurement. This change in optical path length is used to correct the optical path length and adjust the interference state according to the axial length of the examined eye E. The optical path length changing unit 41 is configured, for example, to include a corner prism and a mechanism for moving the corner prism.

[0068] The optical scanner 42 is positioned at or near the optical conjugate position of the pupil of the eye being examined (pupil conjugate position). The optical scanner 42 modifies the direction of travel of the light (measurement light) passing through the optical path for OCT measurement. The optical scanner 42 is controlled by the computation control unit 200 described later and can deflect the measurement light in one or two dimensions.

[0069] The optical scanner 42 includes, for example, a first galvanometer mirror, a second galvanometer mirror, and a mechanism for independently driving these galvanometer mirrors. The first galvanometer mirror deflects the measurement light LS so as to scan the imaging region (fundus Ef or anterior eye) in a horizontal direction (x-direction) orthogonal to the optical axis of the interferometric optical system. The second galvanometer mirror deflects the measurement light LS, which has been deflected by the first galvanometer mirror, so as to scan the imaging region in a vertical direction (y-direction) orthogonal to the optical axis of the interferometric optical system. Thus, the imaging region can be scanned in any direction in the xy-plane using the measurement light LS.

[0070] For example, by simultaneously controlling the orientation of the first galvanometer mirror and the second galvanometer mirror included in the optical scanner 42, the illumination position of the measuring light can be moved along any trajectory on the xy plane. Thus, the imaging area can be scanned according to a desired scanning pattern.

[0071] The OCT focusing lens 45 can move along the optical path (optical axis of the interference optical system) of the measurement light LS. The OCT focusing lens 45 is controlled by the operation control unit 200 described later to move along the optical path of the measurement light LS.

[0072] In some embodiments, a liquid crystal lens or an Alvarez lens is used instead of the OCT focusing lens 45. The liquid crystal lens or Alvarez lens is controlled by the arithmetic control unit 200 in the same way as the OCT focusing lens 45.

[0073] VCC lens 47 is disposed in the optical path of the measuring light, changing at least one of the cylindrical power (astigmatism power) and the cylindrical axis angle (astigmatism axis angle). VCC lens 47 has two cylindrical lenses (optical elements) arranged opposite each other, and is configured to change at least one of the cylindrical power and the cylindrical axis angle by changing at least one of the axial directions of the two cylindrical lenses. In the first embodiment, each of the two cylindrical lenses is configured to rotate independently, so that the two axes change relative to each other. Furthermore, the two cylindrical lenses are configured to rotate integrally while maintaining the angle formed by the two axes.

[0074] The VCC lens 47 is positioned at or near the optical conjugate position of the pupil of the eye being examined. In the first embodiment, the optical scanner 42 is positioned at the optical conjugate position of the pupil of the eye being examined, therefore the VCC lens 47 is positioned near the optical conjugate position of the pupil of the eye being examined.

[0075] When the purpose is to correct the astigmatism of the examined eye E, it can be assumed that even if the VCC lens 47 is positioned near the pupil conjugate position, the deviation of the VCC lens 47's position relative to the pupil conjugate position has little effect on the cylindrical power and cylindrical axis angle changed by the VCC lens 47.

[0076] When the VCC lens 47 is controlled based on ophthalmic data (external or subjective measurements) of the examined eye E, this data primarily refers to measurements taken at the fovea of ​​the examined eye E. However, it can be assumed that the deviation of the VCC lens 47's placement relative to the pupil's conjugate position has a small impact on the cylindrical power and cylindrical axis angle altered by the VCC lens 47. Therefore, even when the imaging site is different from the fovea, the VCC lens 47 can be positioned near the pupil's conjugate position.

[0077] For example Figure 2 As shown, such a VCC lens 47 includes cylindrical lenses 471 and 472 (focal lengths f0 and -f0) with equal refractive power but different designations. Cylindrical lens 471 (VCC1) has a convex surface (positive power) and is configured to rotate in the rotation direction dr1 about the optical path of the measuring light LS (optical axis SO of the interference optical system). Cylindrical lens 472 (VCC2) has a concave surface (negative power) and is configured to rotate in the rotation direction dr2 about the optical axis SO. Cylindrical lenses 471 and 472 are driven by a pulse motor or similar device and rotate independently about the optical axis SO. If cylindrical lenses 471 and 472 rotate in opposite directions, the cylindrical power changes; if cylindrical lenses 471 and 472 rotate together in the same direction, the cylindrical axis angle changes.

[0078] For example, by rotating cylindrical lenses 471 and 472 in opposite directions from a state where the cylindrical axis angles of the cylindrical lenses 471 and 472 are tilted relative to the optical axis SO by a predetermined angle (e.g., 45 degrees), any cylindrical angle can be produced. Alternatively, by rotating cylindrical lenses 471 and 472 together in the same direction, any cylindrical axis angle can be produced.

[0079] [OCT Unit 100] Reference Figure 3Here is an example illustrating the structure of the OCT unit 100. The OCT unit 100 is equipped with an optical system for acquiring OCT images of fundus ef (Ef). This optical system has the same structure as conventional sweep-source type OCT devices. That is, the optical system is an interference optical system that splits light from a wavelength-scanning (wavelength-scanning) light source into a measurement light and a reference light, causing the measurement light passing through the fundus ef (Ef) to interfere with the reference light passing through the reference light path to generate interference light, and detecting this interference light. The detection result (detection signal) of the interference light in the interference optical system is a signal representing the spectrum of the interference light and is sent to the arithmetic control unit 200.

[0080] Like a typical swept-frequency source type OCT device, the light source unit 101 is configured as a wavelength-scanning (wavelength-sweeping) light source capable of scanning (sweeping) the wavelength of the emitted light. The light source unit 101 causes the output wavelength to change over time in the near-infrared band, which is invisible to the naked eye.

[0081] The light L0 output from the light source unit 101 is guided by the optical fiber 102 to the polarization controller 103, where its polarization state is adjusted. The polarization controller 103 adjusts the polarization state of the light L0 guided within the optical fiber 102 by applying stress from the outside to the loop-shaped optical fiber 102.

[0082] The light L0, whose polarization state has been adjusted by the polarization controller 103, is guided by the optical fiber 104 to the optical fiber coupler 105 and split into the measurement light LS and the reference light LR.

[0083] The reference light LR is guided by fiber optic cable 110 to collimator 111, becoming a parallel beam. The parallel beam LR then passes through optical path length correction component 112 and dispersion compensation component 113, and is guided to corner prism 114. Optical path length correction component 112 functions as a delay member to ensure that the optical path lengths (optical distances) of the reference light LR and the measurement light LS are consistent. Dispersion compensation component 113 functions as a dispersion compensation member to ensure that the dispersion characteristics of the reference light LR and the measurement light LS are consistent.

[0084] The corner prism 114 reverses the travel direction of the reference light LR, which is formed into a parallel beam by the collimator 111. The optical path of the reference light LR incident on the corner prism 114 is parallel to the optical path of the reference light LR exiting the corner prism 114. Furthermore, the corner prism 114 can move along the incident and exit optical paths of the reference light LR. This movement changes the length of the optical path (reference optical path) of the reference light LR.

[0085] The reference light LR, after passing through the corner prism 114, is transformed from a parallel beam into a focused beam by the collimator 116 after passing through the dispersion compensation component 113 and the optical path length correction component 112, and then incident on the optical fiber 117. The reference light LR incident on the optical fiber 117 is guided to the polarization controller 118, and the polarization state of the reference light LR is adjusted.

[0086] Polarization controller 118 has, for example, the same structure as polarization controller 103. The reference light LR, whose polarization state has been adjusted by polarization controller 118, is guided by optical fiber 119 to attenuator 120, where the light intensity is adjusted under the control of operational control unit 200. The reference light LR, whose light intensity has been adjusted by attenuator 120, is guided by optical fiber 121 to fiber coupler 122.

[0087] The measurement beam LS generated by fiber coupler 105 is guided by fiber optic cable 127 and formed into a parallel beam by collimating lens unit 40. The parallel beam LS passes through optical path length changing unit 41, optical scanner 42, collimating lens 43, reflecting mirror 44, OCT focusing lens 45, field lens 46, and VCC lens 47, reaching dichroic mirror 48. Then, the measurement beam LS is reflected by dichroic mirror 48, refracted by objective lens 22, and illuminates the fundus Ef. The measurement beam LS is scattered (including reflected) at various depths within the fundus Ef. The backscattered light from the measurement beam LS based on the fundus Ef travels in the opposite direction along the same path as its initial trajectory, is guided to fiber coupler 105, and reaches fiber coupler 122 via fiber optic cable 128.

[0088] Fiber optic coupler 122 combines (interferes) the measurement light LS incident via fiber 128 and the reference light LR incident via fiber 121 to generate interference light. Fiber optic coupler 122 branches the interference light of the measurement light LS and the reference light LR at a predetermined branching ratio (e.g., 50:50), thereby generating a pair of interference lights LC. The pair of interference lights LC emitted from fiber optic coupler 122 are guided to detector 125 by fibers 123 and 124, respectively.

[0089] Detector 125 is, for example, a balanced photodiode having a pair of photodetectors that respectively detect a pair of interferometric LC beams and output the difference between the detection results of the pair of photodetectors. Detector 125 sends the detection result (detection signal) to computation control unit 200. Computation control unit 200 performs Fourier transform, etc., on each wavelength scan (each A-line) of a series of wavelength scans, thereby forming a tomographic image as an OCT image. Computation control unit 200 displays the formed image on display device 3.

[0090] The first embodiment employs a Michelson interferometer, but any type of interferometer, such as a Mach-Zehnder interferometer, can also be used appropriately. In this embodiment, the interferometric optical system, in addition to Figure 3 In addition to the structure shown, it may also include Figure 1 The collimating lens unit 40, optical path length changing unit 41, optical scanner 42, collimating lens 43, reflecting mirror 44, OCT focusing lens 45, field lens 46, and VCC lens 47 shown are examples of an interference optical system according to the embodiment. The VCC lens 47 (and the VCC drive unit 47A described later) is an example of an astigmatism correction optical component according to the embodiment. The OCT focusing lens 45 (and the OCT focusing drive unit 45A described later) is an example of a focus position changing component according to the embodiment. At least one of the optical path length changing unit 41 and the corner prism 114 (and the reference drive unit 114A described later) is an example of an optical path length changing component according to the embodiment. At least one of the polarization controllers 103 and 118 is an example of a polarization state changing component according to the embodiment.

[0091] [Arithmetic control unit 200] Explain the structure of the arithmetic control unit 200.

[0092] exist Figure 4 and Figure 5 A block diagram illustrating a structural example of the processing system (control system) of the ophthalmic device 1 according to the first embodiment is shown. Figure 5 yes Figure 4 The functional block diagram of the structure of the analysis unit 231 is shown below. Figure 4 In, with Figures 1-3 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0093] The arithmetic control unit 200 analyzes the detection signal input from the detector 125 to form an OCT image of the fundus Ef (or anterior eye). The arithmetic processing for this purpose is the same as that of conventional OCT devices with swept frequency sources.

[0094] like Figure 4 As shown, the computation control unit 200 includes a control unit 210 that controls various parts of the fundus camera unit 2, the display device 3, and the OCT unit 100. For example, the computation control unit 200 forms an OCT image of the fundus Ef and displays the formed OCT image on the display device 3.

[0095] The control of the fundus camera unit 2 includes the operation control of the observation light source 11, the shooting light source 15 and LEDs 51 and 61, the operation control of CCD image sensors 35 and 38, the operation control of LCD 39, the movement control of focusing lens 31, the movement control of OCT focusing lens 45, the movement control of reflector 67, the operation control of alignment optical system 50, the movement control of focusing optical system 60, the movement control of optical path length changing unit 41, the drive control of VCC lens 47, and the operation control of light scanner 42.

[0096] The control of the OCT unit 100 includes the operation control of the light source unit 101, the movement control of the corner prism 114, the operation control of the detector 125, the operation control of the attenuator 120, and the operation control of the polarization controllers 103 and 118.

[0097] The arithmetic control unit 200, like a conventional computer, includes a processor, RAM (Random Access Memory), ROM (Read Only Memory), hard disk drive, communication interface, etc. The computer program for controlling the ophthalmic device 1 is stored in the storage device such as the hard disk drive. The arithmetic control unit 200 may include various circuit boards, such as a circuit board for forming OCT images. Furthermore, the arithmetic control unit 200 may also include operating devices (input devices) such as a keyboard and mouse, and display devices such as an LCD.

[0098] Processors include, for example, CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), and programmable logic devices (such as SPLDs (Simple Programmable Logic Devices), CPLDs (Complex Programmable Logic Devices), and FPGAs (Field Programmable Gate Arrays)). The processor implements the functions of the embodiments, for example, by reading and executing programs stored in storage circuits or storage devices. Storage circuits or storage devices may be included within the processor. Alternatively, storage circuits or storage devices may be located externally to the processor. In some embodiments, the functions of the arithmetic control unit 200 are implemented by more than one processor.

[0099] The fundus camera unit 2, display device 3, OCT unit 100 and computing control unit 200 can be configured as a single unit (i.e., within a single housing) or as two or more housings.

[0100] The control unit 210 includes a main control unit 211 and a storage unit 212.

[0101] (Main Control Unit 211) The main control unit 211 performs various controls by outputting control signals to each part of the ophthalmic device 1. In particular, the main control unit 211 controls the CCD image sensors 35 and 38, LCD 39, focusing drive unit 31A, optical path length changing unit 41, optical scanner 42, OCT focusing drive unit 45A, and VCC drive unit 47A for the fundus camera unit 2. Moreover, the main control unit 211 controls the light source unit 101, reference drive unit 114A, polarization controllers 103 and 118, attenuator 120, and detector 125 for the OCT unit 100.

[0102] The main control unit 211 controls the exposure time (charge accumulation time), sensitivity, frame rate, etc. of the CCD image sensor 35 or CCD image sensor 38. In some embodiments, the main control unit 211 controls the CCD image sensor 35 or CCD image sensor 38 to acquire an image of desired quality.

[0103] The main control unit 211 controls the display of fixed targets and visual acuity test targets on the LCD 39. This allows for switching the targets presented to the tested eye E or changing the type of target. Furthermore, by changing the display position of the targets on the LCD 39, the display position of the targets relative to the tested eye E can be altered.

[0104] The focusing drive unit 31A moves the focusing lens 31 along the optical axis. The main control unit 211 controls the focusing drive unit 31A so that the focusing lens 31 is positioned at the desired focusing position. This changes the focusing position of the imaging optical system 30.

[0105] For example, the main control unit 211 analyzes the position of the split-image target in the light-receiving image (split-image target) obtained by the CCD image sensor 35 and controls the focus drive unit 31A and the focusing optical system 60. Alternatively, for example, the main control unit 211 controls the focus drive unit 31A and the focusing optical system 60 in response to user operations on the operation unit 240B (described later) while displaying a real-time image of the examined eye E on the display unit 240A (described later).

[0106] The main control unit 211 changes the optical path length of the measuring light LS by controlling the optical path length changing unit 41. As a result, the difference between the optical path length of the measuring light LS and the optical path length of the reference light LR is changed.

[0107] For example, the main control unit 211 analyzes the detection results of the interference light LC obtained by OCT measurement (or the OCT image formed based on the detection results) and controls the optical path length changing unit 41 in a way that makes the measurement part the desired depth position.

[0108] The main control unit 211 controls the optical scanner 42. The main control unit 211 controls the optical scanner 42 so that the measurement light LS is deflected according to the deflection pattern corresponding to the preset scanning mode.

[0109] Examples of such scanning modes include line scanning, cross scanning, ring scanning, radial scanning, concentric circle scanning, multi-line intersecting scanning, spiral scanning, Lissajous scanning, three-dimensional scanning, and ammonite scanning.

[0110] Line scanning is a scanning mode in which the measurement light LS is deflected in such a way that the trajectory of the irradiation position of the imaging (measuring) part is linear. The direction of the trajectory can be changed (rotated) in the xy plane around the optical axis.

[0111] For example, line scanning includes horizontal scanning and vertical scanning. Horizontal scanning is a scanning mode in which the measurement light LS is deflected so that its trajectory is horizontal (x-direction). Horizontal scanning also includes scanning the measurement light LS along multiple horizontally extending scan lines arranged vertically (y-direction). In this mode, the spacing between the scan lines can be arbitrarily set. Furthermore, by making the spacing between adjacent scan lines sufficiently narrow, a three-dimensional image (three-dimensional scanning) can be formed. The same applies to vertical scanning.

[0112] A cross-scan is a scanning mode in which the measurement light LS is deflected so that its trajectory at the imaging (measuring) location forms a cross shape. For example, a cross-scan can be performed by scanning two lines whose directions intersect. The angle at which the two lines intersect can be varied. In some embodiments, the scan lengths in the B-scan direction of the two lines are the same. In some embodiments, the scan lengths in the B-scan direction of the two lines are different.

[0113] Circular scanning is a scanning mode in which the trajectory of the measurement light LS at the imaging site (measuring site) is rotated in a circular manner, for example, with the optical axis SO as the center. For example, in circular scanning, the measurement light LS is rotated in such a way that the trajectory is a perfect circle, an ellipse, or a part of a circle.

[0114] Radial scanning is a scanning mode in which the trajectory of the measurement light LS at the imaging site (measuring site) is deflected in a radial pattern, for example, around the optical axis SO. In radial scanning, the illumination position of the measurement light LS moves along a radial trajectory consisting of multiple straight lines arranged at predetermined angles. The crosshair scan described above is one type of radial scanning.

[0115] For example, in radial scanning, two or more line scans with different B-scan directions are performed. In some embodiments, the scan lengths of the B-scan directions in the two or more line scans are the same. In some embodiments, the scan length of the B-scan direction in at least one of the two or more line scans is different from the other scan lengths.

[0116] Concentric circle scanning is a scanning mode in which the trajectory of the measurement light LS at the imaging site (measuring site) is arranged in concentric circles, for example, around the optical axis SO, thus deflecting the measurement light LS. For example, in concentric circle scanning, the measurement light LS is deflected so that the trajectories of each circle are perfect circles, ellipses, or arcs (part of a circle). In some embodiments of concentric circle scanning, multiple annular scans with different diameters are performed in combination. Annular scanning is one method of concentric circle scanning.

[0117] Multi-line cross scanning is a scanning pattern in which parallel horizontal scan line groups (e.g., 5 lines) and parallel vertical scan line groups (e.g., 5 lines) are arranged orthogonally near the center of the two scan line groups.

[0118] For example, in each scan line group of a multi-line cross-scan, two or more line scans are performed. In some embodiments, the scan length in the B-scan direction of the two or more line scans is the same. In some embodiments, the scan length in the B-scan direction of at least one of the two or more line scans is different from the other scan lengths.

[0119] Spiral scanning is a scanning mode in which the trajectory of the measurement light LS at the imaging site (measuring site) is rotated in a spiral shape, for example, around the optical axis SO. In spiral scanning, the radius of rotation is gradually decreased (or increased) while the position of the measurement light LS is moved along a spiral trajectory.

[0120] Lissajous scanning is a scanning mode in which the irradiation trajectory of the measurement light LS at the imaging site (measurement site) is deflected such that the irradiation position of the measurement light LS is moved along a Lissajous curve. Lissajous scanning is disclosed, for example, in Japanese Patent Application Publication No. 2018-68578.

[0121] Ammonite scanning is a scanning mode that combines low-speed and high-speed scanning. Specifically, ammonite scanning is a scanning mode in which the scanning reference position (scan center position) of the high-speed circular scan moves along the scanning pattern of the low-speed spiral scan. That is, while the scan center position moves along the spiral scanning pattern, circular scans are performed sequentially with each scan center position as the center.

[0122] By scanning the imaging area with a measurement light LS according to a deflection pattern corresponding to the above scanning mode, a tomographic image as an OCT image can be obtained on the plane formed by the direction along the scan line (scan trajectory) and the fundus depth direction (z direction).

[0123] The OCT focusing drive unit 45A moves the OCT focusing lens 45 along the optical axis of the measurement light LS. The main control unit 211 controls the OCT focusing drive unit 45A to position the OCT focusing lens 45 at the desired focusing position. This changes the focusing position of the measurement light LS. The focusing position of the measurement light LS corresponds to the depth position (z-position) of the beam waist of the measurement light LS.

[0124] For example, the main control unit 211 controls the OCT focusing drive unit 45A based on the signal-to-noise ratio of the detection result of the interference light LC obtained by OCT measurement or an evaluation value (including the statistical value of the evaluation value) corresponding to the image quality of the OCT image formed based on the detection result.

[0125] When a liquid crystal lens or an Alvarez lens is used instead of the OCT focusing lens 45, the main control unit 211 can control the liquid crystal lens or the Alvarez lens in the same way as it controls the OCT focusing drive unit 45A.

[0126] The VCC drive unit 47A causes the cylindrical lenses 471 and 472 to rotate independently about the optical axis of the measuring light LS. This changes at least one of the cylindrical power and the cylindrical axis angle.

[0127] For example, the main control unit 211 controls the VCC drive unit 47A based on the signal-to-noise ratio of the detection result of the interferometric light LC obtained by OCT measurement or an evaluation value (including statistical values ​​of the evaluation value) corresponding to the image quality of the OCT image formed based on the detection result. In some embodiments, the main control unit 211 controls the VCC drive unit 47A based on the signal-to-noise ratio of the detection result of the interferometric light LC obtained by deflecting the measured light LS according to a deflection pattern corresponding to the annular scan or an evaluation value (including statistical values ​​of the evaluation value) corresponding to the image quality of the OCT image formed based on the detection result.

[0128] When a liquid crystal lens, deformable mirror, or Alvarez lens is used instead of VCC lens 47, the main control unit 211 can control the liquid crystal lens, deformable mirror, or Alvarez lens in the same way as the VCC drive unit 47A.

[0129] The main control unit 211 controls the light source unit 101. The control of the light source unit 101 includes switching the light source on and off, controlling the intensity of the emitted light, changing the center frequency of the emitted light, changing the sweep speed of the emitted light, changing the sweep frequency, and changing the sweep wavelength range.

[0130] The reference drive unit 114A moves the corner prism 114, which is positioned in the optical path of the reference light, along the optical path. As a result, the difference between the optical path length of the measuring light LS and the optical path length of the reference light LR is changed.

[0131] For example, the main control unit 211 analyzes the detection results of the interferometric light LC obtained by OCT measurement (or the OCT image formed based on the detection results) and controls the reference drive unit 114A in a way that makes the measurement location the desired depth position. In some embodiments, either the optical path length changing unit 41 or the reference drive unit 114A is provided.

[0132] The main control unit 211 controls the polarization controllers 103 and 118. For example, the main control unit 211 controls the polarization controllers 103 and 118 based on the signal-to-noise ratio of the detection result of the interferometric light LC obtained by OCT measurement or an evaluation value (including statistical values ​​of the evaluation value) corresponding to the image quality of the OCT image formed based on the detection result.

[0133] The main control unit 211 controls the attenuator 120. For example, the main control unit 211 controls the attenuator 120 based on the signal-to-noise ratio of the detection result of the interferometric light LC obtained by OCT measurement or an evaluation value (including statistical values ​​of the evaluation value) corresponding to the image quality of the OCT image formed based on the detection result.

[0134] The main control unit 211 controls the detector 125. The control of the detector 125 includes the control of exposure time (charge accumulation time), sensitivity, frame rate, etc.

[0135] The moving mechanism 150 causes the fundus camera unit 2 (OCT unit 100) to move three-dimensionally relative to the examined eye E. For example, the main control unit 211 can control the moving mechanism 150 to move the optical system installed in the fundus camera unit 2 in three dimensions. This control is used for alignment and tracking. Tracking refers to moving the device's optical system in a way that matches the movement of the examined eye E. When tracking is performed, alignment and focus are performed in advance. Tracking is a function that maintains the proper positional relationship after alignment and focus are achieved by moving the device's optical system in real time, based on images obtained from video capture of the examined eye E, and matching the position and orientation of the examined eye E.

[0136] In some embodiments, the main control unit 211 corrects the position of the scanning range used for OCT imaging in real time based on tracking information obtained through tracking control (tracking information obtained by making the optical system (interference optical system) follow the movement of the examined eye E). The main control unit 211 can control the optical scanner 42 so that the calibrated scanning range is scanned with the measurement light LS.

[0137] In some embodiments, the main control unit 211 controls the optical system constituting the ophthalmic device 1 based on setting information pre-stored in the storage unit 212, thereby changing the optical conditions (shooting conditions, measurement conditions) of the optical system.

[0138] In this embodiment, a prediction measurement (pre-photograph) is performed before the formal measurement (formal imaging). The optical conditions of the optical system are changed based on the detection results of the interferometric light LC obtained in the prediction measurement or the OCT image formed by the detection results, thereby adjusting the measurement conditions for the formal measurement.

[0139] like Figure 4 As shown, the main control unit 211 includes a display control unit 211A.

[0140] The display control unit 211A causes the display device 3 (or the display unit 240A described later) to display various information. The information displayed on the display device 3 includes the imaging results (observation image, OCT image (image of the examined eye formed based on the detection results of interference light LC obtained by scanning with measurement light LS), measurement results (measured values), the image quality evaluation value described later, statistical values ​​calculated based on the evaluation values, and evaluation index information corresponding to the evaluation values, etc. The display control unit 211A can display the image quality evaluation value, statistical value, or evaluation index information of the OCT image in association with the OCT image on the display device 3.

[0141] In addition, the main control unit 211 performs the processing of writing data to the storage unit 212 and the processing of reading data from the storage unit 212.

[0142] (Storage Department 212) Storage unit 212 stores various types of data. Data stored in storage unit 212 includes, for example, image data containing OCT images, fundus image data, and information about the examined eye. The examined eye information includes patient ID, name, and other information related to the examinee, as well as left / right eye identification information and other information related to the examined eye. Additionally, storage unit 212 stores eye examination data pre-acquired by external devices (e.g., ophthalmometer, auto-ophthalmometer), various programs used to operate ophthalmic device 1, and other data. The eye examination data includes the astigmatism power and astigmatic axis angle of the examined eye. The eye examination data may also include the spherical power of the examined eye. The eye examination data may include at least one of the spherical power, astigmatism power, and astigmatic axis angle of the examined eye.

[0143] Additionally, the storage unit 212 stores setting information 212A. Setting information 212A is information used to set the optical conditions of the optical system constituting the ophthalmic device 1. More specifically, setting information 212A is information used to set the optical conditions of the optical system so that the image quality of the image formed based on OCT data reaches a predetermined image quality level or higher; this OCT data is data acquired using the optical system constituting the ophthalmic device 1. In an example of the optical conditions of the optical system constituting the ophthalmic device 1, the settings include the focusing position of the measurement light LS used for OCT, the polarization component of the measurement light LS, the aberration correction component, the optical path length difference between the measurement light LS and the reference light LR, and the position of the optical system relative to the examined eye E.

[0144] The main control unit 211 can control the CCD image sensors 35 and 38, LCD 39, focus drive unit 31A, optical path length change unit 41, light scanner 42, OCT focus drive unit 45A, VCC drive unit 47A, light source unit 101, reference drive unit 114A, polarization controller 103 and 118, attenuator 120, detector 125 and moving mechanism 150 based on the setting information 212A.

[0145] At least a portion of the data stored in storage unit 212 can be stored in a storage unit located outside of ophthalmic device 1. For example, ophthalmic device 1 can be communicatively connected to a server device capable of storing at least a portion of the aforementioned data via a network such as an intra-hospital LAN (Local Area Network). Alternatively, ophthalmic device 1 and the server device can be connected via a WAN (Wide Area Network) such as the Internet. Furthermore, ophthalmic device 1 and the server device can be connected via a network combining LAN and WAN.

[0146] (Image forming unit 220) The image forming unit 220 forms image data of the fundus Ef or the anterior eye OCT image based on the detection signal (interference signal, OCT data) from the detector 125. That is, the image forming unit 220 forms an image of the examined eye E based on the detection result of the interference light LC by the interference optical system. Similar to conventional sweep source type optical coherence tomography, this processing includes noise removal (noise reduction), filtering, FFT (Fast Fourier Transform), and other processing. The image data thus acquired is a dataset of image data formed by imagerizing the reflection intensity distribution in multiple A-lines (paths of each measurement light LS within the examined eye E).

[0147] To improve image quality, multiple datasets collected by repeating scans with the same pattern multiple times can be superimposed (averaged).

[0148] The image forming unit 220 is configured, for example, including the aforementioned circuit board. Furthermore, in this specification, "image data" and "image" based on "image data" are sometimes considered the same. Additionally, the location of the fundus ef region and its image are sometimes considered the same.

[0149] (Data Processing Department 230) The data processing unit 230 performs various data processing (image processing) and analysis on the detection results of the interferometric light LC or the image formed by the image forming unit 220. For example, the data processing unit 230 performs various correction processes such as signal-to-noise ratio analysis of the interferometric signal, brightness correction of the image, and dispersion correction.

[0150] In addition, the data processing unit 230 performs various image processing and analysis on the images (fundus images, anterior eye images, etc.) obtained by the fundus camera unit 2.

[0151] The data processing unit 230 performs known image processing such as interpolation processing to interpolate pixels between two-dimensional tomographic images, forming image data of a three-dimensional image of the fundus Ef or the examined eye E. Furthermore, image data for a three-dimensional image refers to image data where pixel positions are defined by a three-dimensional coordinate system. Image data for a three-dimensional image can be composed of voxels arranged in three dimensions. 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 on the volume data (volume rendering, MIP (Maximum Intensity Projection), etc.) to form image data of a simulated three-dimensional image viewed from a specific viewing direction. This simulated three-dimensional image is displayed on a display device such as the display unit 240A.

[0152] Furthermore, image data as a three-dimensional image can be stacked into multiple tomographic images. Stacked data is image data obtained by arranging multiple tomographic images obtained along multiple scan lines in three dimensions based on the positional relationship of the scan lines. That is, stacked data is image data obtained by representing multiple tomographic images that were originally defined by their respective two-dimensional coordinate systems in a three-dimensional coordinate system (i.e., embedding them in a three-dimensional space).

[0153] The data processing unit 230 is capable of constructing OCTA images (vascular emphasis images, angiography images) that highlight retinal vessels and choroidal vessels based on data collected in a time-series manner via OCT scanning (e.g., B-scan data, OCT data). The OCTA images can be images showing cross-sectional structures or frontal images.

[0154] In some embodiments, the data processing unit 230 compares two OCT images obtained by repeatedly performing B-scans on approximately the same area of ​​the examined eye E, transforms the pixel values ​​of the portion with varying signal intensity into pixel values ​​corresponding to the amount of change, thereby constructing an emphasized image (motion contrast image) highlighting the portion with varying intensity. Furthermore, the data processing unit 230 can extract information corresponding to a predetermined thickness in the desired area from the constructed multiple emphasized images and construct an en-face image, thereby forming an OCTA (Optical Characteristic Angiography) image.

[0155] The data processing unit 230 is capable of aligning fundus images with OCT images. When fundus images and OCT images are acquired in parallel, since the two optical systems are coaxial, the fundus images and OCT images acquired (approximately) simultaneously can be aligned with the optical axis of the imaging optical system 30 as a reference. Furthermore, regardless of the timing of the acquisition of the fundus images and OCT images, alignment can be performed between the OCT image projected onto the xy plane and the fundus image, thereby aligning the OCT image with the fundus image. This alignment method can also be applied when the optical system for fundus image acquisition and the optical system for OCT measurement are not coaxial. Moreover, even when the two optical systems are not coaxial, if the relative positional relationship between the two optical systems is known, the same alignment as when they are coaxial can be performed with reference to that relative positional relationship.

[0156] (Analysis Department 231) The data processing unit 230 includes an analysis unit 231. In addition to the analysis processing described above, the analysis unit 231 is also capable of performing calculation processing of evaluation values ​​(including statistical values ​​of the evaluation values) corresponding to the image quality (e.g., signal-to-noise ratio). The evaluation value calculation processing is performed by analyzing the detection results of the interferometric light LC, the OCT image formed by the image forming unit 220, or a segmented image obtained by segmenting an OCT image. The segmented image can be an image obtained by segmenting an OCT image corresponding to each of a plurality of scanning regions obtained by segmenting the scanning region. Alternatively, the segmented image can be an image obtained by segmenting an OCT image corresponding to each of a plurality of pre-defined scanning regions.

[0157] Based on the analysis results obtained by the analysis unit 231, the main control unit 211 determines the optical conditions for the optical system to achieve a predetermined image quality level or higher, for the entire OCT image or for each segmented image corresponding to a scanned area, and determines setting information for setting the determined optical conditions. The main control unit 211 can determine the setting information for each segmented image corresponding to multiple scanned areas.

[0158] like Figure 5 As shown, the analysis unit 231 includes an image quality evaluation value calculation unit 231A.

[0159] The image quality evaluation value calculation unit 231A calculates any evaluation value that quantitatively represents image quality. Typically, the evaluation value is calculated in such a way that the higher the image quality (image quality), the larger the value. The evaluation value calculation processing performed by the image quality evaluation value calculation unit 231A can be any processing. For example, the image quality evaluation value calculation unit 231A can perform processing using any known techniques such as signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), root mean square (RMS) granularity, Wiener spectrum, modulation transfer function (MTF), and quality index (QI).

[0160] In the first example of the evaluation value calculation process, the image quality evaluation value calculation unit 231A calculates the differential histogram of the image to be calculated, and uses the maximum value of the brightness value (differential value) of the pixels that have a predetermined proportion or higher in the calculated differential histogram throughout the entire image to calculate the image quality evaluation value. Specifically, the image quality evaluation value calculation unit 231A calculates the difference between the maximum and minimum values ​​of the differential values ​​that are above a predetermined threshold (e.g., 20%) as the image quality evaluation value. At this time, the image quality evaluation value is high when the image quality reaches or exceeds a predetermined image quality level, and decreases as the image quality deviates from the predetermined image quality level.

[0161] In the second example of the evaluation value calculation process, the data processing unit 230 (or analysis unit 231) applies a predetermined analysis process (e.g., segmentation process) to the evaluation region, which is a region defined for the image corresponding to a predetermined part in the examined eye E. As a result, the image quality evaluation value calculation unit 231A determines the image region (signal region) corresponding to the desired part (tissue) and the image region other than that (non-signal region). Next, the image quality evaluation value calculation unit 231A generates a luminance histogram in the signal region and a luminance histogram in the non-signal region. Subsequently, the image quality evaluation value calculation unit 231A calculates an evaluation value corresponding to the image quality based on the degree of overlap between these two histograms. For example, the evaluation value is defined in the range of 0 to 100, such that when the two histograms completely overlap, the evaluation value = 0, and when the two histograms completely separate, the evaluation value = 100. This evaluation value calculation may include, for example, normalizing the two histograms, generating a probability distribution function, and calculating the evaluation value using a predetermined formula.

[0162] Furthermore, the image quality evaluation value calculation unit 231A can calculate known parameters representing image quality, such as signal-to-noise ratio (SNR), spatial resolution, and contrast ratio, for the image of the object being calculated. In this case, the image quality evaluation value is higher when the image quality is above a predetermined image quality level, and decreases as the image quality deviates from the predetermined image quality level.

[0163] The image quality evaluation value calculation unit 231A calculates the image quality evaluation value of the entire OCT image, or calculates the image quality evaluation value for each segmented image corresponding to each of the multiple scanning regions.

[0164] Furthermore, the image quality evaluation value calculation unit 231A can calculate statistical values ​​of multiple evaluation values ​​relative to multiple segmented images. Examples of statistical values ​​include maximum value, minimum value, median, mean, mode, range, variance, standard deviation, weighted average with a larger weighting coefficient closer to the region of interest (optical axis of the optical system), or a value using a predetermined evaluation formula that uses any of the above statistical values.

[0165] As an example of an evaluation formula, there is a formula such that the higher the sum of the evaluation values ​​of multiple segmented images and the smaller the fluctuation of the evaluation values ​​of multiple segmented images, the larger the value of the evaluation formula, VCCQ. In this case, for example, the value of the evaluation formula, VCCQ, is the value obtained by dividing the sum of the evaluation values ​​of multiple segmented images by (the standard deviation of the multiple evaluation values ​​+ 1).

[0166] In this embodiment, the main control unit 211 determines setting information for setting the optical conditions of the optical system based on the image quality evaluation value calculated by the image quality evaluation value calculation unit 231A or the statistical value of multiple evaluation values ​​calculated for each segmented image. For example, the main control unit 211 determines the optical conditions of the optical system that reach a predetermined image quality level or higher based on the image quality evaluation value of the entire image, and determines setting information for setting the determined optical conditions. For example, the main control unit 211 determines the optical conditions of the optical system that reach a predetermined image quality level or higher based on the statistical value of the image quality evaluation value of each segmented image corresponding to each of the multiple scanning areas, and determines setting information for setting the determined optical conditions.

[0167] For example, the main control unit 211 determines the setting information for setting the optical conditions of the optical system by repeatedly changing the optical conditions of the optical system and evaluating the image quality evaluation value or the statistical value (or evaluation formula) of multiple evaluation values ​​calculated by the image quality evaluation value calculation unit 231A, so that the image quality evaluation value or the statistical value of multiple evaluation values ​​calculated by the image quality evaluation value calculation unit 231A becomes the maximum (minimum or desired value).

[0168] The display control unit 211A displays the evaluation value or statistical value calculated by the image quality evaluation value calculation unit 231A on the display device 3 or the display unit 240A (display member). In some embodiments, the display control unit 211A displays the evaluation value of at least one of a plurality of segmented images obtained by segmenting an OCT image on the display device 3, etc., in association with the segmented image.

[0169] The data processing unit 230, which functions as described above, is configured, for example, including the aforementioned processor, RAM, ROM, hard disk drive, circuit board, etc. A computer program that enables the microprocessor to perform the aforementioned functions is pre-stored in a storage device such as a hard disk drive.

[0170] (User interface 240) The user interface 240 includes a display unit 240A and an operation unit 240B. The display unit 240A comprises the display device and display apparatus 3 of the aforementioned calculation control unit 200. The operation unit 240B comprises the operation device of the aforementioned calculation control unit 200. The operation unit 240B may include various buttons and keypads provided on the housing and exterior of the ophthalmic device 1. For example, when the fundus camera unit 2 has the same housing as a conventional fundus camera, the operation unit 240B may include a joystick, operation panel, etc., provided on the housing. Furthermore, the display unit 240A may include various display devices such as a touch panel provided on the housing of the fundus camera unit 2.

[0171] Furthermore, the display unit 240A and the operation unit 240B do not need to be configured as separate devices. For example, a device integrating display and operation functions, such as a touch panel, can be used. In this case, the operation unit 240B is configured to include the touch panel and a computer program. The operation content of the operation unit 240B is input to the control unit 210 as an electrical signal input. Alternatively, a graphical user interface (GUI) displayed on the display unit 240A can be used for operation and information input with the operation unit 240B.

[0172] The examined eye E (fundus Ef, anterior eye) is an example of the "object to be measured" in this embodiment. The optical system, optical path length changing unit 41, OCT focusing lens 45, and VCC lens 47 (interference optical system) included in the OCT unit 100 are examples of the "optical system" in this embodiment. The OCT focusing lens 45, corner prism 114, optical path length changing unit 41, and polarization controller 103 are examples of "one or more optical elements" in this embodiment. Measuring the focusing position of light LS, measuring the polarization component of light LS, aberration correction component, measuring the optical path length difference between light LS and reference light LR, or the position of the optical system relative to the examined eye E are examples of the "optical conditions of the optical system" in this embodiment. The ophthalmic device 1 is an example of the "OCT device" in this embodiment. The optical path length changing unit 41, or corner prism 114 and reference drive unit 114A, are examples of the "optical path length difference changing component" in this embodiment. The OCT focusing lens 45 is an example of the "focusing lens" in this embodiment. VCC lens 47 is an example of an "aberration correction device (aberration correction component)" in the embodiment. Display device 3 or display section 240A is an example of a "display member" in the embodiment.

[0173] The following describes the case where the ophthalmic device 1 of the first embodiment performs an ammonite scan as an OCT scan for formal measurement of the examined eye E. However, this embodiment can also be applied to cases where an OCT scan for formal measurement is performed on the examined eye E using a scanning mode other than ammonite scanning.

[0174] Figure 6 An explanatory diagram of ammonite scanning according to the first embodiment is shown.

[0175] The ammonite scanning in the first embodiment is a scanning mode in which the scanning center position of the high-speed scan is moved along the scanning pattern (scanning trajectory) of the low-speed scan, and high-speed scans are performed one or more times sequentially with a predetermined scanning pattern, using the moved scanning center position as a reference. In the ammonite scanning of this embodiment, the high-speed scan is a circular scan, the low-speed scan is a spiral scan, and the sequentially performed circular scans are performed in a manner that intersects with the scanning pattern of the previous circular scan. That is, circular scans are performed sequentially in a manner in which the scanning patterns of two adjacent circular scans intersect.

[0176] exist Figure 6 The image schematically illustrates the scanning pattern Lsc for low-speed scanning and the scanning pattern HS for high-speed scanning. n (n is an integer greater than or equal to 4), HS n-1 HS n-2、 HS n-3 .

[0177] As described above, with regard to ammonite scanning, by combining low-speed and high-speed scanning, the eye E being examined can be scanned from various scanning directions with simple control. In particular, it is possible to scan at high density in a short time in the area near the center of the ammonite scan (the scanning center position of the low-speed scan), and to spend more time scanning at low density further away from the center, thereby enabling the scanning of a wide-angle area including the region of interest with simple control.

[0178] According to this embodiment, by scanning the examined eye E with ammonite scanning, there is no need to remeasure or re-photograph, and the examined eye E can be measured or photographed with a wide angle and higher image quality.

[0179] exist Figure 7 The diagram schematically illustrates an OCT image formed based on OCT data obtained through ammonite scanning according to the first embodiment. Figure 7 For ease of explanation, the process of generating an OCT image will be described, but the same applies to generating an OCT image.

[0180] First, the main control unit 211 sets the scanning area for ammonite scanning for the eye being examined, E. The setting parameters for setting the scanning area for ammonite scanning include the scan start position (scan center position) for low-speed scanning, the scan end position for low-speed scanning, the scan speed for low-speed scanning, the rate of change of the scan radius from the scan start position for low-speed scanning, the scan speed for high-speed scanning, and the scan radius for high-speed scanning.

[0181] The main control unit 211 controls the optical scanner 42 and the OCT unit 100, etc., to repeatedly perform high-speed scanning by moving the scanning center position along the scanning pattern of low-speed scanning and performing two or more high-speed scans (circular scans) centered on the moved scanning center position. The main control unit 211 controls the image forming unit 220 to form an OCT image (tomographic image, B-scan image) based on the acquired OCT data each time a circular scan is performed. Next, the main control unit 211 controls the data processing unit 230 to compare two OCT images obtained by repeatedly performing circular scans (B-scans) on approximately the same area of ​​the examined eye E, and sequentially form an OCTA image. Thus, an OCTA image IMG is formed by arranging the OCTA images formed in the high-speed scanning direction in the low-speed scanning direction.

[0182] Next, the main control unit 211 controls the data processing unit 230 to perform a coordinate transformation to the Cartesian coordinate system for each of the multiple OCTA images formed in the high-speed scanning direction, generating strip images ST0, ST1, ST2, etc. For example, by... Figure 6 A strip image ST0 is obtained by circumferential scanning of the scanning pattern HS0. A strip image ST1 is obtained by circumferential scanning of the scanning pattern HS1, which intersects with HS0. A strip image ST2 is obtained by circumferential scanning of the scanning pattern HS2, which intersects with HS1. At this point, OCTA images containing artifacts caused by the movement or blinking of the examined eye E during the circumferential scanning can be discarded. Only the OCTA images without artifacts are transformed using coordinate transformation to obtain the strip images.

[0183] The main control unit 211 controls the data processing unit 230 to align the strip images ST1, ST2, ... sequentially, using the strip image ST0 as a reference image, thereby generating composite images CIMG0, CIMG1, CIMG2, ... CIMGm (where m is an integer greater than or equal to 2). The data processing unit 230 aligns images based on images within overlapping scan regions in two adjacent strip images (e.g., vascular regions in OCTA images).

[0184] Therefore, it is possible to pass Figure 6 ammonite scanning acquisition Figure 7 The composite image CIMGm.

[0185] [Work Example] An example of the operation of the ophthalmic device 1 according to the first embodiment will be explained.

[0186] Figures 8-11 A diagram illustrating the operation of the predictive measurement performed before the actual measurement in the ophthalmic device 1 of the first embodiment is shown. For example, a ring scan is performed in the predictive measurement, and an ammonite scan is performed in the actual measurement. Alternatively, an ammonite scan can also be performed in the predictive measurement. Additionally, a ring scan can also be performed in the actual measurement.

[0187] Figure 8 A flowchart illustrating an example of the predicted quantity of the ophthalmic device 1 according to the first embodiment is shown. The storage unit 212 stores information for implementing... Figure 8 The computer program for processing is shown. The main control unit 211 operates according to this computer program, thereby executing... Figure 8 The processing shown.

[0188] Figure 9 This schematically illustrates an example of multiple scanning regions obtained by segmenting the scanning region of a predicted amount of OCT scan performed in the ophthalmic device 1 of the first embodiment. Figure 9 In, with Figure 6 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0189] Figure 10 This illustration shows an example of the display of OCT images and image quality evaluation values ​​obtained in the prediction.

[0190] Figure 11 This is another example illustrating the display of OCT images and image quality evaluation values ​​obtained in formal measurements.

[0191] (S1: Set the optical system to the reference position) like Figure 8 As shown, firstly, the main control unit 211 sets the optical conditions of the optical system constituting the ophthalmic device 1 to predetermined initial conditions, and sets the optical system to a reference position based on the set initial conditions.

[0192] (S2: Align) Next, with the fixation target presented at the predetermined fixation position, the main control unit 211 performs alignment adjustment of the optical system relative to the examined eye E. Examples of alignment adjustment include both manual and automatic adjustments.

[0193] When manual alignment is performed, the main control unit 211 projects a pair of alignment indicators onto the eye being examined, E, using the alignment optics system 50. In the display unit 240A, an alignment highlight is displayed as the light-receiving image of these alignment indicators. Additionally, the main control unit 211 displays an alignment scale on the display unit 240A indicating the position of the moving target, which is the pair of alignment highlights. The alignment scale may be, for example, a bracket-shaped image.

[0194] When the positional relationship between the examined eye E and the fundus camera unit 2 (objective lens 22) is appropriate—that is, when the distance (working distance) between the examined eye E and the fundus camera unit 2 is appropriate and the optical axis of the optical system of the fundus camera unit 2 is (approximately) aligned with the axial length (corneal apex position) of the examined eye E—a pair of alignment highlights are temporarily imaged and projected onto the examined eye E at predetermined positions (e.g., the midpoint between the corneal apex and the center of corneal curvature) using known methods. The examiner (user) moves the fundus camera unit 2 three-dimensionally to guide the pair of alignment highlights into the alignment scale, thereby enabling alignment adjustments of the optical system relative to the examined eye E.

[0195] When automatic alignment adjustment is performed, a moving mechanism 150 is used to move the fundus camera unit 2. The data processing unit 230 determines the position of each alignment highlight in the screen displayed on the display unit 240A and calculates the displacement of the determined alignment highlight position relative to the alignment scale. The main control unit 211 moves the fundus camera unit 2 using the moving mechanism 150 to eliminate this displacement. The determination of the position of each alignment highlight can be performed, for example, by calculating the brightness distribution of each alignment highlight and calculating the center of gravity position based on the brightness distribution. Since the position of the alignment scale is fixed, the target displacement can be calculated, for example, by calculating the displacement of the center position of the alignment scale relative to the aforementioned center of gravity position. The moving direction and moving distance of the fundus camera unit 2 can be determined by referring to the unit moving distance in each of the preset x, y, and z directions (for example, by pre-measuring the result that if the fundus camera unit 2 is moved in a certain direction by a certain amount, the alignment index will move in that direction by a certain amount). The main control unit 211 generates a signal corresponding to the determined moving direction and moving distance and sends the signal to the moving mechanism 150. Therefore, the position of the optical system relative to the eye being examined, E, is automatically adjusted.

[0196] (S3: Set the scanning area) The main control unit 211 sets setting parameters for the scanning area of ​​the annular scan used to set the predicted amount. For example, the main control unit 211 sets the setting parameters such that the region of interest in the examined eye E is the scanning center position of the annular scan. In some embodiments, the main control unit 211 sets the above-mentioned setting parameters based on the operation content of the operation unit 240B.

[0197] In some embodiments, when the scanning area for performing a circular scan is set, the main control unit 211, as follows: Figure 9 As shown, the examined eye E is defined as having a central region SAR1, an intermediate region SAR2 surrounding the central region SAR1, and a peripheral region SAR3 surrounding the intermediate region SAR2. The intermediate region SAR2 and the peripheral region SAR3 are examples of "more than one peripheral region" in the implementation method.

[0198] In some embodiments, the above-mentioned setting parameters include parameters for setting the central region SAR1, the intermediate region SAR2, and the peripheral region SAR3. In this case, the main control unit 211 sets the central region SAR1, the intermediate region SAR2, and the peripheral region SAR3 based on the above-mentioned setting parameters.

[0199] (S4: OCT scan) Next, the main control unit 211 controls the optical scanner 42 and the OCT unit 100, etc., to perform a ring scan on each of the multiple scanning areas set in step S3. Specifically, the main control unit 211 performs a ring scan in the central region SAR1, a ring scan in the middle region SAR2, and a ring scan in the peripheral region SAR3.

[0200] (S5: Forming an OCT image) Next, the main control unit 211 controls the image forming unit 220 to sequentially form OCT images based on the OCT data obtained by performing OCT scans on multiple scanning areas sequentially executed in step S4.

[0201] (S6: Calculate image quality evaluation value) Next, the main control unit 211 controls the image quality evaluation value calculation unit 231A to calculate the image quality evaluation value for each of the multiple OCT images formed in each scanning area in step S5.

[0202] In some embodiments, the image quality evaluation value calculation unit 231A calculates the image quality evaluation value of a single image synthesized from multiple OCT images formed in each scanning area in step S5.

[0203] (S7: Search makes the image quality evaluation value the optical condition of the optical system the largest) Next, the main control unit 211 searches for the optical conditions of the optical system for each scanning area in a manner that maximizes the image quality evaluation value calculated in step S6, and determines the optical conditions of the optical system that maximize the image quality evaluation value for each scanning area.

[0204] In this embodiment, the optical conditions of the optical system include the focusing position of the measuring light LS, the polarization component of the measuring light LS, the aberration correction component, the difference in optical path length between the measuring light LS and the reference light LR, and the position of the optical system relative to the eye being examined E.

[0205] The focusing position of the measuring light LS corresponds to its position on the optical axis of the OCT focusing lens 45. The polarization component of the measuring light LS corresponds to the polarization component of the light L0, which is changed by the polarization controller 103. The aberration correction component corresponds to the cylinder power and cylinder axis angle changed by the VCC lens 47. The difference in optical path length between the measuring light LS and the reference light LR corresponds to at least one of the positions of the optical path length changing section 41 (corner prism) in the optical path of the measuring light LS and the corner prism 114 in the optical path of the reference light LR. The position of the optical system relative to the examined eye E corresponds to the position of the optical axis direction of the optical system moved by the moving mechanism 150 and the position of the direction intersecting the optical axis of the optical system moved by the moving mechanism 150.

[0206] In some embodiments, in step S7, the main control unit 211 searches for optical conditions of the optical system in a manner that maximizes the statistical value of the image quality evaluation value for each scanned area calculated in step S6, and determines the optical conditions of the optical system that maximize the statistical value of multiple image quality evaluation values. In this case, an example of a statistical value is the average value.

[0207] (S8: What's next?) Next, the main control unit 211 determines whether to continue searching for the optical conditions of the optical system. For example, if the main control unit 211 determines that the optical conditions of the optical system that maximize the image quality evaluation value have not been determined for all multiple scanning areas, it determines to continue searching for the optical conditions of the optical system. For example, if the main control unit 211 determines that the optical conditions of the optical system that maximize the image quality evaluation value have been determined for all multiple scanning areas, it determines not to continue searching for the optical conditions of the optical system.

[0208] In step S8, if it is determined that the search for optical conditions of the optical system should continue (S8: Yes), the operation of the ophthalmic device 1 proceeds to step S9. In step S8, if it is determined that the search for optical conditions of the optical system should not continue (S8: No), the operation of the ophthalmic device 1 proceeds to step S10.

[0209] (S9: Change the optical conditions of the optical system) When it is determined in step S8 that the search for the optical conditions of the optical system should continue (S8: Yes), the main control unit 211 changes the optical conditions of the optical system. At this time, the main control unit 211 changes one of the parameters that define the optical conditions of the optical system by a predetermined step size, thereby changing the optical conditions of the optical system.

[0210] For example, the main control unit 211 controls the OCT focusing drive unit 45A to move the position on the optical axis of the OCT focusing lens 45 by a predetermined step, thereby changing the optical conditions of the optical system.

[0211] For example, the main control unit 211 controls the polarization controller 103 to change the polarization component of light L0 by a predetermined step size, thereby changing the optical conditions of the optical system.

[0212] For example, the main control unit 211 controls the VCC drive unit 47A to change the cylindrical power or cylindrical axis angle of the VCC lens 47 by a predetermined step, thereby changing the optical conditions of the optical system.

[0213] For example, the main control unit 211 controls the optical path length changing unit 41 or the reference drive unit 114A to change the position of the optical path length changing unit 41 (corner prism) in the optical path of the measuring light LS or the position of the corner prism 114 in the optical path of the reference light LR by a predetermined step size, thereby changing the optical conditions of the optical system.

[0214] For example, the main control unit 211 controls the moving mechanism 150 to change the position of the optical system relative to the optical axis of the eye being examined E or the position in the direction intersecting the optical axis of the optical system by a predetermined step, thereby changing the optical conditions of the optical system.

[0215] Next, in step S9, the operation of the ophthalmic device 1 is transferred to step S4.

[0216] (S10: Save the optical system settings) When it is determined in step S8 that the search for optical conditions of the optical system will not continue (S8: No), the main control unit 211 saves the setting information, including the setting parameters for setting the optical conditions of the optical system determined by repeatedly executing steps S4 to S9, to the storage unit 212 for each scan area. The main control unit 211 can save the setting information, including the calculated image quality evaluation value, to the storage unit 212 for each scan area.

[0217] (S11: Display OCT image and image quality rating) Next, the display control unit 211A displays the OCT image formed in step S5 and the image quality evaluation value calculated in step S6 on the display unit 240A.

[0218] For example, such as Figure 10 As shown, the display control unit 211A displays the OCT image formed in step S5 for each scan area in association with the image quality evaluation value calculated in step S6 for each scan area on the display unit 240A. Figure 10 In the OCT image IMG1 obtained by performing a circular scan of the central region SAR1, the image quality evaluation value VL1 calculated for OCT image IMG1 is displayed in association. Similarly, in the OCT image IMG2 obtained by performing a circular scan of the intermediate region SAR2, the image quality evaluation value VL2 calculated for OCT image IMG2 is displayed in association. Furthermore, in the OCT image IMG3 obtained by performing a circular scan of the surrounding region SAR3, the image quality evaluation value VL3 calculated for OCT image IMG3 is displayed in association.

[0219] Additionally, for example, such as Figure 11 As shown, the display control unit 211A displays the composite image (3D image, frontal image, en-face image) obtained by combining multiple OCT images formed according to each scanning area in step S5, in association with the image quality evaluation value calculated for the composite image in step S6, on the display unit 240A. Figure 11In the composite image IMG0, the image quality evaluation value VL0 calculated for IMG0 is displayed. Similarly, in the OCT image IMG1 obtained by performing a circular scan of the central region SAR1, the image quality evaluation value VL1 calculated for IMG1 is displayed. Likewise, in the OCT image IMG2 obtained by performing a circular scan of the central region SAR2, the image quality evaluation value VL2 calculated for IMG2 is displayed. Finally, in the OCT image IMG3 obtained by performing a circular scan of the surrounding region SAR3, the image quality evaluation value VL3 calculated for IMG3 is displayed.

[0220] The prediction work of ophthalmic device 1 is now complete (terminated).

[0221] Figure 12 A flowchart of a first working example of the ophthalmic device 1 according to the first embodiment is shown. Figure 12 Mainly shown in Figure 8 The example shown illustrates the formal measurement performed after the predicted value. Storage unit 212 stores data for implementing this measurement. Figure 12 The computer program for processing is shown. The main control unit 211 operates according to this computer program and executes... Figure 12 The processing shown.

[0222] (S21: Predicted Quantity) First, the main control unit 211 executes the prediction. Step S21 follows... Figure 8 The process shown is executed. This determines the setting information for setting suitable optical conditions for each scanning area, and the determined setting information is saved in the storage unit 212. Furthermore, the user can confirm the image quality in the formal measurement by referring to the OCT image displayed on the display unit 240A and the corresponding image quality evaluation value, while performing the formal measurement after the prediction.

[0223] (S22: Set the scanning area) Next, the main control unit 211 sets the scanning mode for the formal measurement (e.g., ammonite scanning) and sets the scanning area for the formal measurement for the examined eye E. When the scanning mode for the formal measurement is predetermined and the scanning area for the formal measurement is the same as the scanning area for the predicted quantity, step S22 can be omitted.

[0224] (S23: Set the optical conditions of the optical system) Next, the main control unit 211 determines the scanning position for performing OCT scanning based on the control content of the optical scanner 42 controlled in the formal measurement (control signal for controlling the deflection angle of the polarization plane, etc.), and reads setting information from the storage unit 212 according to the scanning area including the determined scanning position, and sets the optical conditions of the optical system based on the read setting information.

[0225] (S24: OCT scan) Next, the main control unit 211 controls the optical scanner 42 and the OCT unit 100, etc., to perform a formal measurement OCT scan on the set scanning area.

[0226] (S25: Forming an OCT image) Next, the main control unit 211 controls the image forming unit 220 to form an OCT image based on the OCT data obtained in step S24.

[0227] (S26: What's next?) Next, the main control unit 211 determines whether to continue OCT scanning in the next scanning area. For example, the main control unit 211 determines whether a preset scanning area has been covered, and thus determines whether to continue OCT scanning in the next scanning area.

[0228] If it is determined in step S26 that OCT scanning should continue in the next scanning area (S26: Yes), the operation of ophthalmic device 1 proceeds to step S23. If it is determined in step S26 that OCT scanning should not continue in the next scanning area (S26: No), the operation of ophthalmic device 1 proceeds to step S27.

[0229] (S27: Display) When it is determined in step S26 that the OCT scan of the next scanning area will not continue (S26: No), the display control unit 211A displays the OCT image formed in step S25 on the display unit 240A.

[0230] In some embodiments, the main control unit 211 controls the data processing unit 230 to generate a composite image that combines multiple OCT images formed sequentially by repeatedly executing steps S23 to S26. The display control unit 211A enables the generated composite image to be displayed on the display unit 240A.

[0231] The processing of the first working example of formal measurement of ophthalmic device 1 is now complete (terminated).

[0232] As described above, according to the first working example, OCT scanning can be performed under optimal optical conditions for each scanning area, enabling high-precision measurements regardless of the cross-sectional shape of the examined eye E. As a result, even in wide-angle shooting, images with good quality can be obtained regardless of the scanning area.

[0233] The operation of the ophthalmic device 1 in the first embodiment is not limited to... Figure 12 The process is illustrated. For example, the ophthalmic device 1 of the first embodiment can change the optical conditions of the optical system for each scanning area in such a way that the statistical value of the image quality evaluation value calculated for each scanning area in the prediction is maximized, and perform OCT scanning for each scanning area under the changed optical conditions.

[0234] Furthermore, for example, the ophthalmic device 1 of the first embodiment can perform a wide-angle single OCT scan on all scan areas by changing the optical conditions of the optical system for each scan area in a way that maximizes the statistical value of the image quality evaluation value calculated for each scan area in the prediction quantity. Hereinafter, a working example of performing this single OCT scan will be described as a second working example.

[0235] Figure 13 A flowchart of a second working example of the ophthalmic device 1 according to the first embodiment is shown. Figure 13 Mainly shown in Figure 8 The example shown is a formal measurement performed after the predicted value. Storage unit 212 stores data for implementation. Figure 13 The computer program for processing is shown. The main control unit 211 operates according to this computer program, thereby executing... Figure 13 The processing shown.

[0236] (S31: Predicted Quantity) First, the main control unit 211 performs the prediction in the same way as step S21.

[0237] (S32: Set the scanning area) Next, the main control unit 211 sets the scanning mode for the formal measurement (e.g., ammonite scanning) in the same way as in step S22, and sets the scanning area for the formal measurement for the examined eye E. When the scanning mode for the formal measurement is predetermined and the scanning area for the formal measurement is the same as the scanning area for the predicted quantity, step S32 can be omitted.

[0238] (S33: Statistical values ​​for calculating image quality evaluation) Next, the main control unit 211 controls the analysis unit 231 (or the image quality evaluation value calculation unit 231A), and calculates the statistical value of the image quality evaluation value calculated by the image quality evaluation value calculation unit 231A in the predicted quantity of each scanning area based on the scanning area set in step S32, etc. The statistical value may be an average value.

[0239] Step S33 can be performed on the predicted quantity in step S31.

[0240] (S34: Determine optical conditions based on statistical values) Next, the main control unit 211 determines the optical conditions of the optical system based on the statistical values ​​calculated in step S33. For example, the main control unit 211 determines the optical conditions of the optical system in a manner that maximizes the statistical values ​​(average values) of multiple image quality evaluation values ​​corresponding to multiple scanning areas.

[0241] (S35: Set the optical conditions of the optical system) Next, the main control unit 211 sets the optical conditions of the optical system in a manner that becomes the optical conditions determined in step S34.

[0242] (S36: OCT scan) Next, under the optical conditions set in step S35, the main control unit 211 controls the optical scanner 42 and the OCT unit 100, etc., to perform a single OCT scan for formal measurement of the entire scanning area.

[0243] (S37: Forming an OCT image) Next, the main control unit 211 controls the image forming unit 220 to form an OCT image based on the OCT data obtained in step S36.

[0244] (S38: Display) Next, the display control unit 211A displays the OCT image formed in step S37 on the display unit 240A.

[0245] The processing of the second working example of formal measurement of ophthalmic device 1 is now complete (terminated).

[0246] As explained above, according to the second working example, OCT scanning can be performed on the entire scanning area under optimal single optical conditions, enabling high-precision measurements regardless of the cross-sectional shape of the examined eye E. As a result, even in wide-angle shooting, images with appropriate image quality can be obtained regardless of the scanning area.

[0247] Furthermore, in the first embodiment, it was described that the focus position of the measurement light LS used for OCT, the polarization component of the measurement light LS, the aberration correction component, the optical path length difference between the measurement light LS and the reference light LR, and the position of the optical system relative to the examined eye E were changed according to each scanning area. However, the structure of the embodiment is not limited to this. In some embodiments, according to each scanning area, at least one of the following can be changed as optical conditions of the optical system: the focus position of the measurement light LS used for OCT, the polarization component of the measurement light LS, the aberration correction component, the optical path length difference between the measurement light LS and the reference light LR, and the position of the optical system relative to the examined eye E. That is, according to each scanning area, as optical conditions of the optical system, the focus position of the measurement light LS used for OCT, the polarization component of the measurement light LS, the aberration correction component, the optical path length difference between the measurement light LS and the reference light LR, or the position of the optical system relative to the examined eye E can be changed.

[0248] <Second Implementation> In the first embodiment, the case where a VCC lens 47 is provided in the ophthalmic device as an aberration correction device is described, but the structure of the embodiment is not limited to this. For example, the ophthalmic device of the embodiment may include a wavefront aberration correction optical system as an aberration correction device.

[0249] The following description focuses on the differences between the structure of the second embodiment and that of the first embodiment.

[0250] Figure 14 An example of the structure of the optical system of the ophthalmic device 1a according to the second embodiment is shown. Figure 14 In, with Figure 1 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0251] The optical system structure of the ophthalmic device 1a in the second embodiment differs from that of the ophthalmic device 1 in the first embodiment in that: a fundus camera unit 2a is provided instead of a fundus camera unit 2, and a computation control unit 200a is provided instead of a computation control unit 200.

[0252] The difference between the structure of fundus camera unit 2a and fundus camera unit 2 is that wavefront aberration correction optical system 70 is used instead of VCC lens 47. The difference between the operation control unit 200a and operation control unit 200 is that the wavefront aberration correction optical system 70 is used instead of VCC lens 47.

[0253] The wavefront aberration correction optical system 70 includes a beam splitter 71, a transmission-type compensation optical element 72, a relay lens 73, a lens array 74, and a wavefront sensor 75.

[0254] exist Figure 14 In this configuration, the beam splitter 71 and the compensating optical element 72 are disposed between the collimating lens unit 40 and the optical path length changing unit 41. The compensating optical element 72 is disposed between the beam splitter 71 and the optical path length changing unit 41.

[0255] Beam splitter 71 branches the return light of the measurement light LS into light directed towards the collimating lens unit 40 and light directed towards the relay lens 73. Beam splitter 71 can change the branching ratio of these lights. For example, when the compensation optics 72 described later is controlled (e.g., for prediction), the return light of the measurement light LS is branched into two beams with a branching ratio of "50:50". Furthermore, when the compensation optics 72 is not controlled (e.g., for formal measurement), the return light of the measurement light LS can be branched into two beams with a branching ratio of "90:10" to increase the amount of light directed towards the collimating lens unit 40.

[0256] The compensation optical element 72 may be, for example, a deformable phase plate (DPP). The compensation optical element 72 is an optical element that can locally change the wavefront phase of the light to be transmitted.

[0257] A relay lens 73, a lens array 74, and a wavefront sensor 75 are arranged in the reflection direction of the beam splitter 71. Each of the compensating optical element 72 and the lens array 74 is arranged at or near a position optically conjugate to the pupil of the examined eye E (pupil conjugate position).

[0258] Beam splitter 71 allows the measurement light LS from collimating lens unit 40 to pass through and be guided to compensating optics 72, and guides the return light of the measurement light LS from the examined eye E, which passes through compensating optics 72, to relay lens 73. Compensating optics 72 at least corrects the wavefront aberration of the return light of the measurement light LS. The return light of the measurement light LS, guided to relay lens 73, is then guided to lens array 74.

[0259] The lens array 74 includes multiple lenses arranged in an array, generating multiple focused beams from the light passing through the relay lens 73. The multiple focused beams generated by the lens array 74 illuminate the sensor surface of the wavefront sensor 75. The wavefront sensor 75 can be, for example, a CMOS image sensor or a CCD image sensor.

[0260] Based on the detection results of multiple beams obtained by the wavefront sensor 75, the wavefront of the light passing through the compensation optics 72 can be locally altered. Thus, the compensation optics 72 can correct the wavefront aberration of the return light from the measurement light LS originating from the examined eye E.

[0261] Figure 15A block diagram showing a structural example of the processing system of the ophthalmic device 1a according to the second embodiment is provided. Figure 15 In, with Figure 4 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0262] The difference between the processing system of the ophthalmic device 1a in the second embodiment and the processing system of the ophthalmic device 1 in the first embodiment is that the wavefront aberration correction optical system 70 is used instead of the VCC lens 47, and a control unit 210a is provided instead of the control unit 210.

[0263] The control unit 210a includes a main control unit 211a and a storage unit 212a. The difference between the control unit 210a and the control unit 210 is that the control wavefront aberration correction optical system 70 replaces the VCC drive unit 47A.

[0264] That is, according to the second embodiment, by controlling the wavefront aberration correction optical system 70, the aberration correction components can be changed, and the optical conditions of the optical system can be changed.

[0265] The wavefront aberration correction optical system 70 is an example of an "aberration correction device" in the embodiment. The optical system, optical path length changing unit 41, OCT focusing lens 45, and wavefront aberration correction optical system 70 (interference optical system) included in the OCT unit 100 are examples of an "optical system" in the embodiment.

[0266] <Third Implementation Method> In the first or second embodiment, the OCT image obtained from the prediction and the image quality evaluation value are displayed together on the display unit 240A, but the structure of the embodiment is not limited to this. For example, the OCT image obtained from the prediction can be displayed on the display unit 240A, and information representing the image quality evaluation index of the OCT image can be displayed. The information representing the image quality evaluation index can be generated, for example, based on the image quality evaluation value.

[0267] Hereinafter, the ophthalmic device of the third embodiment will be described, focusing on the differences between it and the ophthalmic device 1 of the first embodiment.

[0268] Figure 16 A block diagram showing an example of the structure of the analysis unit 231 is provided. Figure 16 In the middle, to and Figure 5 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0269] Figure 16 The structure of the analysis unit 231 in the third embodiment shown is similar to... Figure 5 The difference in the structure of the analysis unit 231 in the first embodiment shown is that an image quality evaluation index information generation unit 231B is added.

[0270] The image quality evaluation index information generation unit 231B generates image quality evaluation index information for the OCT image, which is the object of the image quality evaluation value calculation. Examples of image quality evaluation index information include information indicating image quality evaluation, information indicating image quality good or bad, and information indicating image quality level. The information indicating the evaluation index includes text representing the evaluation index, images representing the evaluation index, and colors representing the evaluation index.

[0271] For example, the image quality evaluation index information generation unit 231B compares the image quality evaluation value generated by the image quality evaluation value calculation unit 231A with the image quality evaluation threshold corresponding to a predetermined evaluation level, and generates information representing the image quality evaluation corresponding to the comparison result.

[0272] For example, the image quality evaluation index information generation unit 231B compares the image quality evaluation value generated by the image quality evaluation value calculation unit 231A with a predetermined image quality evaluation threshold. As a result of the comparison, the image quality evaluation index information generation unit 231B generates information indicating good image quality when the image quality evaluation value is above the image quality evaluation threshold, and generates information indicating poor image quality when the image quality evaluation value is below the image quality evaluation threshold.

[0273] For example, the image quality evaluation index information generation unit 231B compares the image quality evaluation value generated by the image quality evaluation value calculation unit 231A with one or more predetermined image quality evaluation thresholds that are different from each other. As a result of the comparison, the image quality evaluation index information generation unit 231B generates information representing the image quality level based on the image quality evaluation threshold that is determined to be the highest image quality level among the image quality evaluation thresholds that are determined to be above the image quality evaluation threshold.

[0274] Figure 17 and Figure 18 A diagram illustrating the operation of the predicted quantity performed in the ophthalmic device of the third embodiment before the formal measurement is shown.

[0275] Figure 17 A flowchart illustrating an example of the predictive measurement operation of the ophthalmic device according to the third embodiment is shown. Storage unit 212 stores data for implementing... Figure 17 The computer program for processing is shown. The main control unit 211 operates according to this computer program, thereby executing... Figure 17 The processing shown.

[0276] Figure 18 An example illustrating the display of image quality evaluation index information in association with a composite image of multiple OCT images obtained by OCT scanning of a predicted amount performed in the ophthalmic device of the third embodiment and OCT images of each scanned region. Figure 18 In, with Figure 11The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0277] (S41: Set the optical system to the reference position) First, similar to step S1, the main control unit 211 sets the optical conditions of the optical system constituting the ophthalmic device 1 to predetermined initial conditions, and sets the optical system to a reference position based on the set initial conditions.

[0278] (S42: Align) Next, the main control unit 211 performs the same alignment adjustment of the optical system relative to the eye being examined, as in step S2.

[0279] (S43: Set the scanning area) Similar to step S3, the main control unit 211 sets setting parameters for the scanning area of ​​the annular scan used to set the predicted amount. For example, the main control unit 211 sets the setting parameters such that the region of interest in the examined eye E becomes the scanning center position of the annular scan. In some embodiments, the main control unit 211 sets the above-mentioned setting parameters based on the operation content of the operation unit 240B.

[0280] (S44: OCT scan) Next, similarly to step S4, the main control unit 211 controls the optical scanner 42 and the OCT unit 100 to perform a ring scan on each of the multiple scanning areas set in step S43. Specifically, the main control unit 211 performs a ring scan in the central region SAR1, a ring scan in the middle region SAR2, and a ring scan in the peripheral region SAR3.

[0281] (S45: Forming an OCT image) Next, the main control unit 211 controls the image forming unit 220 in the same manner as in step S5, to sequentially form OCT images based on the OCT data obtained by sequentially performing OCT scans on multiple scanning areas in step S4.

[0282] (S46: Calculate image quality evaluation value) Next, the main control unit 211 controls the image quality evaluation value calculation unit 231A in the same way as in step S6 to calculate the image quality evaluation value for each of the multiple OCT images formed in step S45 according to each scanning area.

[0283] (S47: Searching for the optical conditions that make the image quality evaluation value the largest optical system) Next, the main control unit 211, similarly to step S7, searches for the optical conditions of the optical system for each scanning area in a manner that maximizes the image quality evaluation value calculated in step S46, and determines the optical conditions of the optical system that maximize the image quality evaluation value for each scanning area.

[0284] In some embodiments, in step S47, the main control unit 211 searches for optical conditions of the optical system in a manner that maximizes the statistical value of the image quality evaluation value for each scanned area calculated in step S46, and determines the optical conditions of the optical system that maximize the statistical value of multiple image quality evaluation values. In this case, an average value is an example of such a statistical value.

[0285] (S48: What's next?) Next, the main control unit 211, in the same manner as in step S8, determines whether to continue searching for the optical conditions of the optical system.

[0286] If it is determined in step S48 that the search for optical conditions of the optical system should continue (S48: Yes), the operation of the ophthalmic device proceeds to step S49. If it is determined in step S48 that the search for optical conditions of the optical system should not continue (S48: No), the operation of the ophthalmic device proceeds to step S50.

[0287] (S49: Change the optical conditions of the optical system) When it is determined in step S48 that the search for the optical conditions of the optical system should continue (S48: Yes), the main control unit 211 changes the optical conditions of the optical system in the same way as in step S9. At this time, the main control unit 211 changes one of the parameters that define the optical conditions of the optical system by a predetermined step size, thereby changing the optical conditions of the optical system.

[0288] Following step S49, the operation of the ophthalmic device transitions to step S44.

[0289] (S50: Save the optical system settings) When it is determined in step S48 that the search for optical conditions of the optical system will not continue (S48: No), the main control unit 211, similarly to step S10, saves the setting information for setting the optical conditions of the optical system, determined by repeatedly executing steps S44 to S49, to the storage unit 212 for each scan area. The main control unit 211 can save the setting information, including the calculated image quality evaluation value, to the storage unit 212 for each scan area.

[0290] (S51: Evaluation metrics for generated image quality) Next, the main control unit 211 controls the image quality evaluation index information generation unit 231B to generate image quality evaluation index information based on the image quality evaluation value calculated in step S46.

[0291] In some embodiments, the main control unit 211 controls the image quality evaluation index information generation unit 231B to generate image quality evaluation index information based on the image quality evaluation value calculated for the composite image obtained by combining multiple OCT images formed by each scanning area in step S45.

[0292] (S52: Display) Next, the display control unit 211A displays the OCT image formed in step S45, the image quality evaluation value calculated in step S46, and the image quality evaluation index information generated in step S51 on the display unit 240A.

[0293] For example, such as Figure 18 As shown, the display control unit 211A displays the OCT image formed in step S45 for each scanning area in association with the image quality evaluation value calculated in step S46 for each scanning area and the image quality evaluation index information calculated in step S51 on the display unit 240A.

[0294] exist Figure 18 In the image quality evaluation system, evaluation indicator bars are displayed. The higher the image quality level, the more indicator bars are colored. For example, a predetermined number of indicator bars (e.g., 3) representing good image quality are colored red, while bars representing even better image quality are colored green, depending on the quality level. This allows users to easily determine the image quality level of an OCT image.

[0295] In addition, Figure 18 In the OCT image IMG1 obtained by performing a circular scan on the central region SAR1, the image quality evaluation value VL1 calculated for the OCT image IMG1 and the evaluation index bars colored according to the image quality evaluation value VL1 are displayed in association. Similarly, in the OCT image IMG2 obtained by performing a circular scan on the intermediate region SAR2, the image quality evaluation value VL2 calculated for the OCT image IMG2 and the evaluation index bars colored according to the image quality evaluation value VL2 are displayed in association. Furthermore, in the OCT image IMG3 obtained by performing a circular scan on the surrounding region SAR3, the image quality evaluation value VL3 calculated for the OCT image IMG3 and the evaluation index bars colored according to the image quality evaluation value VL2 are displayed in association.

[0296] Additionally, for example, such as Figure 18As shown, the display control unit 211A displays the composite image (3D image, frontal image, en-face image) obtained by combining multiple OCT images formed according to each scanning area in step S45, along with the image quality evaluation value VL0 calculated for the composite image and the image quality evaluation index information generated based on the image quality evaluation value VL0, on the display unit 240A. Figure 18 In the en-face image IMG0, which is a composite image, the image quality evaluation value VL0 calculated for the en-face image IMG0 and the evaluation index bar colored according to the image quality evaluation value VL0 are displayed in association.

[0297] The prediction work of the ophthalmic device of the third embodiment is now complete (terminated).

[0298] [effect] This describes the implementation of the OCT device, its control method, and its procedure.

[0299] The first embodiment is an OCT device (ophthalmic device 1, 1a) including an optical system (optical system included in OCT unit 100, optical path length changing unit 41, OCT focusing lens 45 and VCC lens 47 (or wavefront aberration correction optical system 70), interference optical system), a storage unit (212, 212a), and a control unit (210, 210a, main control unit 211, main control unit 211a). The optical system is configured to change optical conditions (focus position of the measurement light LS, polarization component of the measurement light LS, aberration correction component, optical path length difference between the measurement light LS and the reference light LR, or position of the optical system relative to the examined eye E). The optical system is configured to acquire OCT data of the measured object (examined eye E) by scanning the measured object (examined eye E) with the measurement light (LS). The storage unit pre-stores setting information (212A), which is used to set the optical conditions of the optical system for each scanning area of ​​the object being measured, so that the image quality formed based on OCT data is at or above a predetermined image quality level. The control unit performs OCT on the object being measured by changing the optical conditions of the optical system based on the setting information according to the scanning area of ​​the measurement light in the object being measured.

[0300] In this manner, setting information for the optical system is stored in advance for each scanning area of ​​the measurement light. Based on this setting information, the optical conditions of the optical system are changed according to the scanning area to perform OCT on the object being measured. As a result, regardless of the cross-sectional shape of the object being measured, an image of the object can be acquired with good image quality, and the measurement time (image capture time) can be shortened.

[0301] In a second embodiment, according to the first embodiment, the scanning area includes: a central region (SAR1) of the object being measured, including the optical axis of the optical system; and one or more peripheral regions (intermediate region SAR2, peripheral region SAR3) surrounding the central region.

[0302] In this manner, optical conditions for the optical system are pre-stored for each of the central region and one or more peripheral regions. Based on the scanning area, the optical conditions of the optical system are changed to perform OCT on the object being measured. As a result, regardless of the cross-sectional shape of the object being measured, images of the central region and one or more peripheral regions can be acquired with good image quality, thus shortening the measurement time (image capture time).

[0303] In a third embodiment, according to either the first or second embodiment, the optical system includes an interferometric optical system (the optical system included in the OCT unit 100, the optical path length changing unit 41, the OCT focusing lens 45, and the VCC lens 47 (or the wavefront aberration correction optical system 70)) and an optical path length difference changing component (optical path length changing unit 41, or corner prism 114 and reference drive unit 114A). The interferometric optical system splits the light (L0) from the light source (light source unit 101) into a measurement light (LS) and a reference light (LR). The measurement light, which has passed through the measurement optical path configured with one or more optical elements (OCT focusing lens 45, corner prism 114, optical path length changing unit 41, polarization controller 103), is projected onto the object being measured, and the interference light (LC) between the return light from the object being measured and the reference light that has passed through the reference optical path is detected. The optical path length difference changing component changes the difference between the optical path length of the measurement light and the optical path length of the reference light. The control unit controls at least one of one or more optical elements and optical path length difference changing components based on the setting information, thereby changing the optical conditions of the optical system and performing OCT on the object being measured.

[0304] In this manner, for each scanning area, at least one of one or more optical elements and an optical path length difference changing component is controlled based on setting information. This allows for the adjustment of the optical conditions of the optical system according to the scanning area, thereby performing OCT on the object being measured. Consequently, regardless of the cross-sectional shape of the object, images of the object can be acquired with good image quality, reducing measurement time (image capture time).

[0305] In the fourth embodiment, according to the third embodiment, one or more optical elements include a focusing lens (OCT focusing lens 45) or an aberration correction device (VCC lens 47 or wavefront aberration correction optical system 70).

[0306] In this manner, for each scanning area, based on setting information, at least one of one or more optical elements, including a focusing lens or aberration correction device and an optical path length difference alteration component, is controlled. This alters the optical conditions of the optical system according to the scanning area to perform OCT on the object being measured. Therefore, regardless of the cross-sectional shape of the object being measured, an image of the object can be acquired with good image quality, and the measurement time (image capture time) can be shortened.

[0307] In a fifth embodiment, according to either the first or second embodiment, a moving mechanism (150) is included to move the optical system relative to the object being measured. The control unit controls the moving mechanism based on setting information, thereby changing the optical conditions of the optical system and performing OCT on the object being measured.

[0308] In this manner, setting information for the optical system's optical conditions is pre-stored for each scanning area of ​​the measurement light. Based on the setting information and the scanning area, the optical system is moved relative to the object being measured, thereby changing the optical conditions and performing OCT on the object. As a result, regardless of the cross-sectional shape of the object, images of the object can be acquired with good image quality, and measurement time (image capture time) can be shortened.

[0309] In a sixth embodiment, depending on either the first or second embodiment, an image forming unit (220) and an image quality evaluation value calculation unit (231A) are included. The image forming unit forms an image of the object to be measured for each scan area based on OCT data. The image quality evaluation value calculation unit calculates the image quality evaluation value (image quality evaluation value) of the image of the object to be measured. The control unit determines, for each scan area, the optical conditions of the optical system that maximize the image quality based on the evaluation value.

[0310] In this way, since the optical conditions of the optical system are determined based on the image quality evaluation value of each scanned area, images of the object being measured can be acquired with good image quality regardless of the cross-sectional shape of the object, thus shortening the measurement time (shooting time).

[0311] In the seventh embodiment, according to the sixth embodiment, the control unit displays the image quality evaluation value of the object to be measured on the display member (display unit 240A, display device 3) for each scanning area.

[0312] In this way, the image quality evaluation value displayed on the display component can be referenced for each scanned area, allowing for the formal OCT measurement to be performed while simultaneously confirming the image quality variations based on the cross-sectional shape of the object being measured. As a result, the need for remeasurement (re-shooting) can be reduced, and the measurement time (shooting time) can be shortened.

[0313] In the eighth embodiment, according to the seventh embodiment, the control unit displays the image of the scanned area formed by the image forming unit in association with the evaluation value on the display member.

[0314] In this way, since the image of the scanned area formed by the image forming unit is displayed on the display member in association with the evaluation value, the image quality can be easily confirmed.

[0315] In the ninth embodiment, according to the sixth embodiment, the control unit displays evaluation index information (image quality evaluation index information) representing the image quality of the measured object image on the display member (display unit 240A, display device 3) for each scanning area.

[0316] In this way, since the image quality of the measured object can be evaluated based on the evaluation index information, the image quality can be easily confirmed.

[0317] In the tenth embodiment, according to the ninth embodiment, the control unit displays the image of the scanned area formed by the image forming unit in association with evaluation index information on the display member.

[0318] In this way, since the image of the scanned area formed by the image forming unit is displayed on the display component in association with the evaluation index information, the image quality can be more easily confirmed.

[0319] In the eleventh embodiment, according to the sixth embodiment, the control unit changes the optical conditions of the optical system based on the statistical values ​​of the image quality evaluation values ​​of the images in multiple scanning areas (maximum value, minimum value, median, average value, mode, range, variance, standard deviation, weighted average value with a larger weight coefficient closer to the area of ​​interest (optical axis of the optical system), or the value of a predetermined evaluation formula using any of the above statistical values) and performs OCT on the object to be measured.

[0320] In this way, statistical values ​​of image quality evaluation displayed on the display component can be used to refer to each scanned area, allowing for the simultaneous confirmation of image quality variations based on the cross-sectional shape of the object being measured while performing formal OCT measurements. As a result, the need for remeasurement (re-shooting) is reduced, and measurement time (shooting time) is shortened.

[0321] The twelfth embodiment is a control method for an OCT device, which includes an optical system (the optical system included in the OCT unit 100, an optical path length changing unit 41, an OCT focusing lens 45 and a VCC lens 47 (or a wavefront aberration correction optical system 70), and an interference optical system). The optical system is configured to acquire OCT data of the object being measured by scanning it with a measurement light (LS). The optical system is configured to be able to change optical conditions (the focusing position of the measurement light LS, the polarization component of the measurement light LS, the aberration correction component, the optical path length difference between the measurement light LS and the reference light LR, or the position of the optical system relative to the examined eye E). The control method for the OCT device includes a control step in which the optical conditions of the optical system are changed according to the scanning area of ​​the measurement light in the object being measured, based on setting information, to perform OCT on the object being measured. The setting information is used to set the optical conditions of the optical system for each scanning area in the object being measured in such a way that the image quality formed based on the OCT data is at or above a predetermined image quality level.

[0322] In this manner, setting information for the optical system is pre-stored for each scanning area of ​​the measurement light. Based on the setting information, the optical conditions of the optical system are changed according to the scanning area to perform OCT on the object being measured. As a result, regardless of the cross-sectional shape of the object being measured, an image of the object can be acquired with good image quality, and the measurement time (image capture time) can be shortened.

[0323] In the thirteenth embodiment, according to the twelfth embodiment, the scanning area includes: a central region (SAR1) of the object being measured, including the optical axis of the optical system; and one or more peripheral regions (intermediate region SAR2, peripheral region SAR3) surrounding the central region.

[0324] In this manner, optical conditions for the optical system are pre-stored for each of the central region and one or more peripheral regions. Based on the scanning area, the optical conditions of the optical system are changed to perform OCT on the object being measured. As a result, regardless of the cross-sectional shape of the object being measured, images of the object can be acquired with good image quality in the central region and one or more peripheral regions, thus shortening the measurement time (image capture time).

[0325] In the fourteenth embodiment, according to the twelfth or thirteenth embodiment, the optical system includes an interferometric optical system (the optical system included in the OCT unit 100, the optical path length changing unit 41, the OCT focusing lens 45, and the VCC lens 47 (or the wavefront aberration correction optical system 70)) and an optical path length difference changing component (optical path length changing unit 41, or corner prism 114 and reference drive unit 114A). The interferometric optical system splits the light (L0) from the light source (light source unit 101) into a measurement light (LS) and a reference light (LR). The measurement light, which has passed through the measurement optical path configured with one or more optical elements (OCT focusing lens 45, corner prism 114, optical path length changing unit 41, polarization controller 103), is projected onto the object to be measured, and the interference light (LC) between the return light from the object to be measured and the reference light that has passed through the reference optical path is detected. The optical path length difference changing component changes the difference between the optical path length of the measurement light and the optical path length of the reference light. In the control step, at least one of one or more optical elements and optical path length difference changing components is controlled based on the setting information, thereby changing the optical conditions of the optical system and performing OCT on the object to be measured.

[0326] In this manner, for each scanning area, at least one of one or more optical elements and an optical path length difference adjustment component is controlled based on setting information. This allows for the modification of the optical system's optical conditions according to the scanning area to perform OCT on the object being measured. Consequently, regardless of the cross-sectional shape of the object, images of the object can be acquired with good image quality, thus shortening the measurement time (image capture time).

[0327] In the fifteenth embodiment, according to the fourteenth embodiment, one or more optical elements include a focusing lens (OCT focusing lens 45) or an aberration correction device (VCC lens 47 or wavefront aberration correction optical system 70).

[0328] In this manner, for each scanning area, based on setting information, at least one of one or more optical elements, including a focusing lens or aberration correction device and an optical path length difference alteration component, is controlled. This allows for the modification of the optical system's optical conditions according to the scanning area to perform OCT on the object being measured. Consequently, regardless of the cross-sectional shape of the object, images of the object can be acquired with good image quality, reducing measurement time (image capture time).

[0329] In the sixteenth embodiment, according to the twelfth or thirteenth embodiment, the OCT device includes a moving mechanism (150) that moves the optical system relative to the object being measured. In the control step, the moving mechanism is controlled based on setting information, thereby changing the optical conditions of the optical system to perform OCT on the object being measured.

[0330] In this manner, setting information for the optical system's optical conditions is pre-stored for each scanning area of ​​the measurement light. Based on the setting information, the optical system's optical conditions are changed by moving it relative to the object being measured, according to the scanning area, and OCT is performed on the object. Thus, regardless of the object's cross-sectional shape, images of the object can be acquired with good image quality, and measurement time (image capture time) can be shortened.

[0331] In the seventeenth embodiment, according to the twelfth or thirteenth embodiment, an image forming step and an image quality evaluation value calculation step are included. In the image forming step, an image of the object being measured is formed for each scan area based on OCT data. In the image quality evaluation value calculation step, an image quality evaluation value (image quality evaluation value) of the image of the object being measured is calculated. In the control step, for each scan area, the optical conditions of the optical system are determined based on the evaluation value in a manner that maximizes the image quality.

[0332] In this way, since the optical conditions of the optical system are determined based on the image quality evaluation value of each scanned area, images of the object being measured can be acquired with good image quality regardless of the cross-sectional shape of the object, thus shortening the measurement time (shooting time).

[0333] In the eighteenth embodiment, according to the seventeenth embodiment, a display control step is included, in which the image quality evaluation value of the object to be measured is displayed on the display member (display unit 240A, display device 3) for each scanning area.

[0334] In this way, for each scanned area, the image quality evaluation value displayed on the display component can be referenced, thereby enabling the formal OCT measurement to be performed while simultaneously confirming the image quality variations based on the cross-sectional shape of the object being measured. As a result, the chances of re-measurement (re-shooting) are reduced, and the measurement time (shooting time) can be shortened.

[0335] In the nineteenth embodiment, according to the eighteenth embodiment, in the display control step, the image of the scanned area formed in the image forming step is displayed on the display member in association with the evaluation value.

[0336] In this way, since the image of the scanned area formed in the image formation step is displayed on the display component in association with the evaluation value, the image quality can be easily confirmed.

[0337] In the twentieth embodiment, according to the seventeenth embodiment, a display control step is included, in which evaluation index information (image quality evaluation index information) representing the image quality of the measured object is displayed on the display member (display unit 240A, display device 3) for each scanning area.

[0338] In this way, the image quality of the measured object can be evaluated based on the evaluation index information, thus making it easy to confirm the image quality.

[0339] In the twenty-first embodiment, according to the twenty-first embodiment, in the display control step, the image of the scanned area formed in the image forming step is displayed on the display component in association with the evaluation index information.

[0340] In this way, since the image of the scanned area formed by the image forming unit is displayed on the display component in association with the evaluation index information, the image quality can be more easily confirmed.

[0341] In the twenty-second embodiment, according to the seventeenth embodiment, in the control step, the optical conditions of the optical system are changed based on the statistical values ​​of the image quality evaluation values ​​of the images in multiple scanning areas (maximum value, minimum value, median, average value, mode, range, variance, standard deviation, weighted average value with a larger weight coefficient closer to the part of interest (optical axis of the optical system), or the value of a predetermined evaluation formula using any of the above statistical values), and OCT is performed on the object to be measured.

[0342] In this way, for each scanned area, statistical values ​​of the image quality evaluation displayed on the display component can be referenced, thereby enabling the formal OCT measurement to be performed while simultaneously confirming the image quality variations based on the cross-sectional shape of the object being measured. As a result, the need for remeasurement (re-shooting) can be reduced, and measurement time (shooting time) can be shortened.

[0343] The twenty-third embodiment is a program that causes a computer to execute the steps of the control method for the OCT device described in any of the twelfth to twenty-second embodiments.

[0344] In this manner, setting information for the optical system is pre-stored for each scanning area of ​​the measurement light. Based on the setting information, the optical conditions of the optical system are changed according to the scanning area to perform OCT on the object being measured. As a result, regardless of the cross-sectional shape of the object being measured, an image of the object can be acquired with good image quality, and the measurement time (image capture time) can be shortened.

[0345] The structure described above is merely one example for preferably implementing the present invention. Therefore, any modifications (omissions, substitutions, additions, etc.) within the scope of the present invention can be appropriately implemented. For example, the appropriate structure can be selected depending on the purpose. Furthermore, with the appropriate structure, effects that are obvious to those skilled in the art and effects described in this specification can be obtained.

[0346] (Explanation of reference numerals in the attached image) 1.1a Ophthalmic device 3 Display devices 41 Optical Path Length Variation Unit 45 OCT focusing lens 47 VCC lens 47A VCC Drive Unit 70 Wavefront aberration correction optical system 100 OCT units 103, 118 Polarization Controller 114 Corner Prism 114A Reference Drive Unit 200, 200a Operation Control Unit 210, 210a Control Department 211, 211a Main Control Unit 211A Display Control Unit 212, 212a Storage Section 212A Configuration Information 220 Image forming unit 230 Data Processing Department 231 Analysis Department 231A Image Quality Evaluation Value Calculation Department 231B Image Quality Evaluation Index Information Generation Department 240A Display Unit E The examined eye SAR1 central region SAR2 intermediate region SAR3 surrounding area LC interference light LR reference light LS measurement of light

Claims

1. An optical coherence tomography (OCT) device, comprising: An optical system is configured to change optical conditions and to acquire optical coherence tomography data of the object being measured by scanning the object with measurement light. The storage unit stores pre-stored setting information, which is used to set the optical conditions of the optical system according to each scanning area of ​​the object being measured, so that the image quality of the image formed based on the optical coherence tomography data is above a predetermined image quality level. as well as The control unit performs optical coherence tomography on the object under test by changing the optical conditions of the optical system based on the setting information, according to the scanning area of ​​the measurement light in the object under test.

2. The optical coherence tomography apparatus according to claim 1, characterized in that, The scanning area includes: the central region of the object being measured, which includes the optical axis of the optical system; and one or more peripheral regions surrounding the central region.

3. The optical coherence tomography apparatus according to claim 1 or 2, characterized in that, The optical system includes: An interferometric optical system splits light from a light source into a measurement beam and a reference beam. The measurement beam, having passed through a measurement optical path equipped with one or more optical elements, is projected onto the object under test. The system detects the interference between the return light from the object under test and the reference beam that has passed through the reference optical path. The optical path length difference changing component changes the difference between the optical path length of the measuring light and the optical path length of the reference light. The control unit controls at least one of the more than one optical element and the optical path length difference changing component based on the setting information, thereby changing the optical conditions of the optical system to perform optical coherence tomography on the object being measured.

4. The optical coherence tomography apparatus according to claim 3, characterized in that, The one or more optical elements include focusing lenses or aberration correction devices.

5. The optical coherence tomography apparatus according to claim 1 or 2, characterized in that, The optical coherence tomography apparatus includes a movement mechanism that moves the optical system relative to the object being measured. The control unit controls the moving mechanism based on the setting information, thereby changing the optical conditions of the optical system to perform optical coherence tomography on the object being measured.

6. The optical coherence tomography apparatus according to claim 1 or 2, characterized in that, The optical coherence tomography device includes: The image forming unit forms an image of the object under test for each scanned region based on the optical coherence tomography (OCT) data; and The image quality evaluation value calculation unit calculates the image quality evaluation value of the object being measured. The control unit determines the optical conditions of the optical system for each of the scanning areas based on the evaluation value in a manner that maximizes the image quality.

7. The optical coherence tomography apparatus according to claim 6, characterized in that, The control unit displays the image quality evaluation value of the object being measured on the display component for each scanning area.

8. The optical coherence tomography apparatus according to claim 7, characterized in that, The control unit causes the image of the scanned area formed by the image forming unit to be displayed on the display member in association with the evaluation value.

9. The optical coherence tomography apparatus according to claim 6, characterized in that, The control unit displays evaluation index information, representing the image quality of the measured object, on the display component for each scanning area.

10. The optical coherence tomography apparatus according to claim 9, characterized in that, The control unit causes the image of the scanned area formed by the image forming unit to be displayed on the display member in association with the evaluation index information.

11. The optical coherence tomography apparatus according to claim 6, characterized in that, The control unit changes the optical conditions of the optical system based on statistical values ​​of the image quality evaluation values ​​of images in multiple scanning areas, and performs optical coherence tomography on the object being measured.

12. A control method for an optical coherence tomography (OCT) apparatus, the OCT apparatus comprising an optical system configured to change optical conditions and configured to acquire OCT data of the measured object by scanning the measured object with measurement light. The control method includes a control step in which the optical conditions of the optical system are changed based on setting information according to the scanning area of ​​the measurement light in the object being measured to perform optical coherence tomography (OCT) scanning of the object being measured. The setting information is used to set the optical conditions of the optical system for each scanning area in the object being measured in such a way that the image quality formed based on the OCT data is above a predetermined image quality level.

13. The control method for the optical coherence tomography apparatus according to claim 12, characterized in that, The scanning area includes: the central region of the object being measured, which includes the optical axis of the optical system; and one or more peripheral regions surrounding the central region.

14. The control method for the optical coherence tomography apparatus according to claim 12 or 13, characterized in that, The optical system includes: An interferometric optical system splits light from a light source into a measurement beam and a reference beam. The measurement beam, having passed through a measurement optical path equipped with one or more optical elements, is projected onto the object under test. The system detects the interference between the return light from the object under test and the reference beam that has passed through the reference optical path. The optical path length difference changing component changes the difference between the optical path length of the measuring light and the optical path length of the reference light. In the control step, at least one of the more than one optical element and the optical path length difference changing component is controlled based on the setting information, thereby changing the optical conditions of the optical system to perform optical coherence tomography on the object to be measured.

15. The control method for the optical coherence tomography apparatus according to claim 14, characterized in that, The one or more optical elements include focusing lenses or aberration correction devices.

16. The control method for the optical coherence tomography apparatus according to claim 12 or 13, characterized in that, The optical coherence tomography apparatus includes a movement mechanism that moves the optical system relative to the object being measured. In the control step, the moving mechanism is controlled based on the setting information, thereby changing the optical conditions of the optical system to perform optical coherence tomography on the object being measured.

17. The control method for the optical coherence tomography apparatus according to claim 12 or 13, characterized in that, The control method includes: The image formation step involves forming an image of the object under test for each scanned region based on the optical coherence tomography (OCT) data; and The image quality evaluation value calculation steps involve calculating the image quality evaluation value of the object being measured. In the control step, for each of the scanned areas, the optical conditions of the optical system are determined based on the evaluation value in a manner that maximizes the image quality.

18. The control method for the optical coherence tomography apparatus according to claim 17, characterized in that, The control method includes a display control step, in which an evaluation value of the image quality of the object being measured is displayed on a display component for each scan area.

19. The control method for the optical coherence tomography apparatus according to claim 18, characterized in that, In the display control step, the image of the scanned area formed in the image forming step is displayed on the display member in association with the evaluation value.

20. The control method for the optical coherence tomography apparatus according to claim 17, characterized in that, The control method includes a display control step, in which evaluation index information representing the image quality of the object being measured is displayed on a display component for each scan area.

21. The control method for the optical coherence tomography apparatus according to claim 20, characterized in that, In the display control step, the image of the scanned area formed in the image forming step is displayed on the display component in association with the evaluation index information.

22. The control method for the optical coherence tomography apparatus according to claim 17, characterized in that, In the control step, the optical conditions of the optical system are changed based on statistical values ​​of image quality evaluation values ​​of images in multiple scanning areas to perform optical coherence tomography on the object under test.

23. A program, characterized in that, The computer executes each step of the control method for the optical coherence tomography apparatus of claim 12 or 13.

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