Analysis processing device, optical coherence tomography device, analysis processing method, and program

Abstract

This analysis processing device includes an acquisition unit, an analysis unit, and a display control unit. The acquisition unit acquires two or more items of motion contrast data for the same cross-section of an object under measurement at mutually different inter-scan time intervals, the motion contrast data being obtained by repeating a B-scan three or more times on the cross-section. The analysis unit executes an analysis process for deriving the temporal variation of motion contrast intensity in the cross-section on the basis of the two or more items of motion contrast data. The display control unit causes a display means to display an image representing the temporal variation obtained using the analysis process.

Description

Analysis processing device, optical coherence tomography device, analysis processing method, and program

[0001] The present invention relates to an analysis processing device, an optical coherence tomography device, an analysis processing method, and a program.

[0002] Optical coherence tomography (OCT) is a well-known technique that uses a light beam from a laser light source or the like to form images that represent the surface or internal morphology of an object under test. Because OCT is non-invasive to living organisms, it is expected to find widespread application, particularly in the medical and biological fields. For example, in the field of ophthalmology, devices that form images of the fundus, cornea, and the like have been put to practical use. Such devices using OCT techniques (OCT devices) can be used to observe various parts of the subject's eye. Furthermore, because they can obtain high-resolution images, they are used to diagnose various ophthalmic diseases.

[0003] In particular, OCT angiography (OCTA) has attracted attention in recent years as a method for imaging components that change within a short time between OCT scans by repeatedly performing OCT scans on the same location on a subject. OCTA is used as a method for noninvasively visualizing information about the structure of the retinal and choroidal vasculature in vivo.

[0004] For example, Patent Document 1, Patent Document 2, and Non-Patent Document 1 disclose Variable Interscan Time Analysis (VISTA) that analyzes relative blood flow velocity by utilizing the dependency of OCTA signals (OCTA images) on interscan time (time between scans).

[0005] For example, as described in Non-Patent Document 1, the use of VISTA can provide the relative blood flow distribution of the retinal / choroidal vascular layers, such as the superficial retinal layer, the deep retinal layer, and the choriocapillaris. VISTA is expected to be used to evaluate the activity of blood vessels, particularly capillaries and neovessels.

[0006] US Patent Application Publication No. 2018 / 0315194 US Patent Application Publication No. 2020 / 0064118

[0007] Stefan B. Ploner et al. , “Toward quantitative OCT angiography: visualizing blood flow speeds in ocular pathology using variable interscan time analysis (VISTA)”, Retina. Author manuscript; available in PMC 2017 December 01

[0008] Generally, three-dimensional volume data of a measured object is acquired by performing an OCT scan, a region of interest is identified in a projection image generated from the acquired volume data, and VISTA is executed to observe the identified region of interest in detail. With such conventional VISTA, it is virtually impossible to acquire time analysis results, such as the time variation of relative blood flow velocity, in real time.

[0009] In addition, VISTA requires repeated OCT scans of the same location on the object to be measured, which significantly increases the measurement and analysis times compared to OCTA, and also significantly increases the amount of data required for analysis. As a result, conventional VISTA cannot obtain analysis results in real time, and although it can provide the spatial distribution of relative blood flow velocity, it cannot provide the time change in relative blood flow velocity.

[0010] Furthermore, in VISTA, it is necessary to adjust the scan parameters of the OCT scan according to the region of interest in order to obtain useful time analysis results, but there is no means to adjust the scan parameters while observing the region of interest in the object to be measured in real time.

[0011] The present invention has been made in view of the above circumstances, and one of its objects is to provide a new technique for acquiring VISTA analysis results for a device under test in real time.

[0012] One aspect of the embodiment is an analysis processing device that includes an acquisition unit that acquires two or more motion contrast data of the same cross section of a measured object at different inter-scan time intervals, obtained by repeatedly performing B-scans three or more times on the same cross section of the measured object; an analysis unit that executes an analysis process to determine the time variation of motion contrast intensity in the cross section based on the two or more motion contrast data; and a display control unit that displays an image representing the time variation obtained by the analysis process on a display means.

[0013] Another aspect of the embodiment is an optical coherence tomography device including: an optical system that performs optical coherence tomography on the object to be measured; and the above-mentioned analysis processing device that displays an image representing the time variation on the display means based on the two or more motion contrast data obtained by repeatedly performing B-scans three or more times on the same cross section of the object to be measured using the optical system.

[0014] Yet another aspect of the embodiment is an analysis processing method including: an acquisition step of acquiring two or more pieces of motion contrast data of the same cross section of a measured object at mutually different inter-scan time intervals, the data being obtained by repeatedly performing B-scans three or more times on the same cross section; an analysis step of executing an analysis process of determining a time variation in motion contrast intensity of the cross section based on the two or more pieces of motion contrast data; and a display control step of displaying an image representing the time variation obtained by the analysis process on a display means.

[0015] Yet another aspect of the embodiment is a program that causes a computer to execute each step of the above-described analysis processing method.

[0016] Yet another aspect of the embodiment is a computer program product including computer programs / instructions that, when executed by a processor, implement the steps of the above-described analysis processing method.

[0017] Yet another aspect of the embodiment is a computer-readable storage medium (recording medium) having stored thereon a computer program / instruction, which, when executed by a processor, implements each step of the above-described analysis processing method.

[0018] According to the present invention, it is possible to provide a new technique for acquiring VISTA analysis results for an object to be measured in real time.

[0019] FIG. 1 is a schematic diagram showing an example of the configuration of an analysis system according to an embodiment. FIG. 1 is a schematic diagram showing an example of the configuration of an analysis processing device according to an embodiment. FIG. 1 is a schematic diagram for explaining VISTA ... showing another example of the configuration of an analysis system according to an embodiment. FIG. 1 is a schematic diagram for explaining an example of the configuration of an optical system of an ophthalmic apparatus according to an embodiment. FIG. 1 is a schematic diagram for explaining an example of the configuration of an optical system of an ophthalmic apparatus according to an embodiment. FIG. 1 is a schematic diagram for explaining an example of the configuration of a processing system of an ophthalmic apparatus according to an embodiment. FIG. 1 is a schematic diagram for explaining an example of the configuration of a processing system of an ophthalmic apparatus according to an embodiment. FIG. 1 is a flow chart of an example of the operation of an ophthalmic apparatus according to an embodiment. FIG. 1 is a flow chart of an example of the operation of an ophthalmic apparatus according to an embodiment. FIG. 1 is a flow chart of an example of the operation of an ophthalmic apparatus according to an embodiment.

[0020] An example of an embodiment of an analysis processing device, an optical coherence tomography device, an analysis processing method, and a program according to the present invention will be described in detail with reference to the drawings. Note that in the embodiment, it is possible to arbitrarily use the techniques described in the documents cited in this specification.

[0021] The analysis processing device according to the embodiment acquires two or more pieces of motion contrast data for cross sections at mutually different inter-scan time intervals, which are obtained by repeatedly performing B-scans three or more times on (substantially) the same cross section of a measured object. The analysis processing device executes an analysis process to determine a time variation in motion contrast intensity for the cross section based on the two or more pieces of motion contrast data acquired, and causes a display unit to display an image representing the time variation in motion contrast intensity obtained by the analysis process.

[0022] Motion contrast data is data that represents the distribution of contrast intensity that changes due to motion. Motion contrast data is generated from the difference (or uncorrelated components) between two B-scan data obtained by performing B-scans on the same cross section of a measured object at different scan timings. The inter-scan time corresponds to the time between two B-scan timings. An example of motion contrast data is a motion contrast image.

[0023] An example of an image representing temporal variations in motion contrast intensity is an image in which, for each pixel, brightness information corresponding to the statistical value of the motion contrast intensity and hue information corresponding to the saturation time of the motion contrast intensity are assigned.

[0024] This makes it possible to perform VISTA (Variable Interscan Time Analysis) based on B-scan images, which significantly reduces the measurement time and the time required for analysis, as well as the amount of data required for analysis. As a result, it becomes possible to generate VISTA analysis results in real time, and also to display the VISTA analysis results on a display means in real time.

[0025] In addition, since it becomes possible to generate VISTA analysis results in real time, scan parameters including interscan time and the number of B-scan repetitions can be easily optimized, thereby improving the accuracy of the analysis results.

[0026] Furthermore, it is also possible to automatically or manually specify a vascular region within a B-scan image, perform a time analysis of the relative blood flow in the specified vascular region, and obtain the results of the time analysis of the relative blood flow in real time.

[0027] In some embodiments, the analysis processing device generates two or more motion contrast data of a cross section of the object to be measured at different inter-scan time intervals from measurement data obtained by an external measurement device. In some embodiments, the analysis processing device repeatedly performs B-scans three or more times on the same cross section of the object to be measured, and generates two or more motion contrast data of the cross section of the object to be measured at different inter-scan time intervals from the obtained measurement data.

[0028] The B-scan according to the embodiment may be a B-scan using ultrasound or a B-scan using electromagnetic waves including light. An example of a B-scan using light is a B-scan using optical coherence tomography (OCT).

[0029] An analysis processing method according to an embodiment includes one or more steps executed by the analysis processing device. A program (computer program) / instructions according to an embodiment cause a computer (processor) to execute each step of the analysis processing method according to an embodiment. A computer program product according to an embodiment includes a computer program / instructions. When the computer program / instructions are executed by a processor, the computer program product realizes each step of the analysis processing method according to an embodiment. A recording medium according to an embodiment is a computer-readable non-transitory storage medium (recording medium) on which a program according to an embodiment is recorded (stored). A computer-readable storage medium according to an embodiment stores a computer program / instructions. When the computer program / instructions are executed by a processor, the computer-readable storage medium realizes each step of the analysis processing method according to an embodiment.

[0030] In this specification, a processor includes circuits such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), and a programmable logic device (e.g., an SPLD (Simple Programmable Logic Device), a CPLD (Complex Programmable Logic Device), and an FPGA (Field Programmable Gate Array)). The processor realizes the functions of the embodiment by, for example, reading and executing a program stored in a memory circuit or a storage device. The memory circuit or storage device may be included in the processor. Furthermore, the memory circuitry or memory device may be provided external to the processor.

[0031] The following description will mainly focus on a case where VISTA processing is performed using motion contrast data obtained by performing an OCT B-scan on a living eye as a measurement object. However, the following embodiment can also be applied to a case where a B-scan other than an OCT is performed on a measurement object. The following embodiment can also be applied to a case where an OCT B-scan is performed on a measurement object other than a living eye. The following embodiment can also be applied to a case where a B-scan other than an OCT is performed on a measurement object other than a living eye.

[0032] <Analysis System> FIG. 1 shows a block diagram of an example of the configuration of an analysis system according to an embodiment.

[0033] The analysis system 1000 includes an analysis processing device 1100 , an OCT device 1200 , and a display device 1300 .

[0034] The OCT device 1200 includes an OCT optical system. The OCT optical system includes an interference optical system. The interference optical system splits light from a light source into measurement light and reference light, irradiates the split measurement light onto an object under test, superimposes return light of the measurement light from the object under test on the reference light that has passed through a reference optical path to generate interference light, and detects the generated interference light. The OCT device 1200 forms OCT data (OCT image) based on the detected interference light, and generates OCTA data (OCTA image) from two or more of the formed OCT data.

[0035] Specifically, the OCT device 1200 repeatedly performs OCT B-scans on the same cross section of the object to be measured three or more times, and sequentially forms three or more OCT images (B-scan images, tomographic images) representing the structure of the cross section based on the obtained measurement data. Furthermore, the OCT device 1200 generates two or more motion contrast data of the cross section at different inter-scan time intervals from the three or more formed OCT images. The motion contrast data includes OCTA images, OCTA data, etc.

[0036] The analysis processing device 1100 acquires two or more pieces of motion contrast data generated by the OCT device 1200 and performs an analysis process to determine the time variation of motion contrast intensity in a cross section based on the acquired two or more pieces of motion contrast data. This analysis process may be a process to execute VISTA. The analysis processing device 1100 displays an image representing the time variation of motion contrast intensity obtained by the analysis process on the display device 1300 in real time.

[0037] Fig. 2 is a block diagram showing an example of the configuration of the analysis processing device 1100 shown in Fig. 1. In Fig. 2, the same parts as those in Fig. 1 are given the same reference numerals, and the description thereof will be omitted where appropriate.

[0038] The analysis processing device 1100 includes an acquisition unit 1110, an analysis unit 1120, and a display control unit 1130. The acquisition unit 1110 acquires two or more pieces of motion contrast data of cross sections at different inter-scan time intervals generated by the OCT device 1200.

[0039] For example, the function of the acquisition unit 1110 is realized by a communication unit that establishes a communication connection with the OCT device 1200. In some embodiments, the acquisition unit 1110 is configured to acquire three or more OCT images (OCT data) formed sequentially by the OCT device 1200, and generate two or more pieces of motion contrast data of cross sections at different inter-scan time intervals from the acquired three or more OCT images.

[0040] The analysis unit 1120 includes a VISTA processing unit 1121 and a flow parameter analysis unit 1122 .

[0041] The VISTA processing unit 1121 identifies time variation in motion contrast intensity in a cross section by performing VISTA processing using two or more pieces of motion contrast data acquired by the acquisition unit 1110. The VISTA processing unit 1121 generates, as an analysis result, a VISTA image that represents the distribution of the identified time variation in motion contrast intensity.

[0042] The flow parameter analysis unit 1122 identifies, as a flow parameter, a time variation in motion contrast intensity at a position specified in the VISTA image generated by the VISTA processing unit 1121. The position specified in the VISTA image may be a position specified by the user, or may be a position specified by analyzing the VISTA image.

[0043] The flow parameter analysis unit 1122 is capable of generating information representing the time change of the motion contrast intensity at a specified position on a cross section. For example, the acquisition unit 1110 acquires two or more contrast data groups acquired at different timings, each including the above-mentioned two or more motion contrast data. At this time, the VISTA processing unit 1121 sequentially executes VISTA on each of the two or more contrast data groups, and sequentially generates two or more VISTA images corresponding to each of the two or more contrast data groups. The flow parameter analysis unit 1122 identifies the time change of the motion contrast intensity at each specified position in the two or more VISTA images as flow parameters, and generates information representing the time change of the flow parameters.

[0044] The display control unit 1130 causes the display device 1300 to display in real time the analysis results obtained by the analysis processing executed by the analysis unit 1120. For example, the display control unit 1130 causes the display device 1300 to display at least one of the VISTA image generated by the VISTA processing unit 1121, information representing the time variation of motion contrast intensity (flow parameters) generated by the flow parameter analysis unit 1122, and information representing the time change of the flow parameters.

[0045] Furthermore, when the acquisition unit 1110 acquires the above two or more contrast data groups, the display control unit 1130 can simultaneously display two or more VISTA images generated sequentially by the VISTA processing unit 1121 on the screen of the display device 1300. The display control unit 1130 may also display two or more VISTA images sequentially in chronological order at the same position on the screen of the display device 1300 (slow display, moving image display).

[0046] 2 is realized by one or more processors. At this time, the processor controls VISTA and the display device 1300 (and, in some cases, generates OCTA images and motion contrast data) in accordance with a pre-stored program.

[0047] Here, a VISTA according to an embodiment will be described, taking a living eye as an example of the object to be measured.

[0048] 3 to 8 are explanatory diagrams of VISTA executed by the VISTA processing unit 1121 in FIG.

[0049] Fig. 3 is a schematic representation of an example of a VISTA image at time t = T1 generated from five OCT images obtained by repeatedly performing OCT B-scans on a cross section passing through the macula of a living eye. Fig. 4 is a schematic representation of an example of a VISTA image at time t = T2 (T1 < T2) generated from five OCT images obtained by repeatedly performing OCT B-scans on the same cross section as Fig. 3. In Fig. 4, parts similar to those in Fig. 3 are designated by the same reference numerals, and descriptions thereof will be omitted where appropriate.

[0050] The OCT apparatus 1200 repeatedly performs OCT B-scans on the same cross section of the macula of a living eye. For example, as shown in FIG. 3 , the OCT apparatus 1200 performs B-scans at times t1, t2, ..., t7, sequentially forming B-scan images IM1 to IM7 at the scan timing of each B-scan. Hereinafter, the time intervals (inter-scan time intervals) between times t1 and t7 are assumed to be the same, but the time intervals between times t1 and t7 may be different from each other.

[0051] Next, the OCT device 1200 (or the analysis processing device 1100) generates four OCTA images IMA11 to IMA14 at different inter-scan time intervals from the B-scan images IM1 to IM5 that were formed first among the B-scan images IM1 to IM7, as shown in Fig. 3. The four OCTA images IMA11 to IMA14 have the same image size, and each position of the living eye is depicted at the same pixel position in each of the OCTA images IMA11 to IMA14.

[0052] The OCTA image IMA11 is generated from the difference between two B-scan images having an inter-scan time interval Δt=ti, which is the scan timing interval. The two B-scan images are B-scan images IM1 and IM2, B-scan images IM2 and IM3, B-scan images IM3 and IM4, or B-scan images IM4 and IM5.

[0053] In some embodiments, the OCTA image IMA11 is an average image of two or more of the following OCTA images: an OCTA image generated from the difference between B-scan images IM1 and IM2; an OCTA image generated from the difference between B-scan images IM2 and IM3; an OCTA image generated from the difference between B-scan images IM3 and IM4; and an OCTA image generated from the difference between B-scan images IM4 and IM5.

[0054] The OCTA image IMA12 is generated from the difference between two B-scan images with an inter-scan time interval Δt=2×ti, which are B-scan images IM1 and IM3, B-scan images IM2 and IM4, or B-scan images IM3 and IM5.

[0055] In some embodiments, the OCTA image IMA12 is an average image of two or more of the following OCTA images: an OCTA image generated from the difference between B-scan images IM1 and IM3; an OCTA image generated from the difference between B-scan images IM2 and IM4; and an OCTA image generated from the difference between B-scan images IM3 and IM5.

[0056] The OCTA image IMA13 is generated from the difference between two B-scan images with an inter-scan time interval Δt=3×ti, which are B-scan images IM1 and IM4 or B-scan images IM2 and IM5.

[0057] In some embodiments, OCTA image IMA13 is an averaged image of an OCTA image generated from the difference between B-scan images IM1 and IM4, and an OCTA image generated from the difference between B-scan images IM2 and IM5.

[0058] The OCTA image IMA14 is generated from the difference between two B-scan images with an inter-scan time interval Δt=4×ti, which are B-scan images IM1 and IM5.

[0059] The analysis processing device 1100 acquires the above-mentioned OCTA images IMA11 to IMA14 generated sequentially by the OCT device 1200, and generates a VISTA image VMA1 at time t=T1 by analyzing the acquired OCTA images IMA11 to IMA14. The time t=T1 may be the time of the scan timing of any of the OCTA images IMA11 to IMA14 used to generate the VISTA image VMA1, or a statistical value (average value or median value) of the scan timings (times) of the OCTA images IMA11 to IMA14 used to generate the VISTA image VMA1.

[0060] Similarly, the OCT device 1200 (or the analysis processing device 1100) generates four OCTA images IMA21 to IMA24 at different inter-scan time intervals from the B-scan images IM2 to IM6 among the B-scan images IM1 to IM7, as shown in FIG.

[0061] The OCTA image IMA21 is generated from the difference between two B-scan images with an inter-scan time interval Δt=ti, which are B-scan images IM2 and IM3, B-scan images IM3 and IM4, B-scan images IM4 and IM5, or B-scan images IM5 and IM6.

[0062] In some embodiments, OCTA image IMA21 is an average image of two or more of the following OCTA images: an OCTA image generated from the difference between B-scan images IM2 and IM3; an OCTA image generated from the difference between B-scan images IM3 and IM4; an OCTA image generated from the difference between B-scan images IM4 and IM5; and an OCTA image generated from the difference between B-scan images IM5 and IM6.

[0063] The OCTA image IMA22 is generated from the difference between two B-scan images with an inter-scan time interval Δt=2×ti, which are B-scan images IM2 and IM4, B-scan images IM3 and IM5, or B-scan images IM4 and IM6.

[0064] In some embodiments, the OCTA image IMA22 is an average image of two or more of the following OCTA images: an OCTA image generated from the difference between B-scan images IM2 and IM4; an OCTA image generated from the difference between B-scan images IM3 and IM5; and an OCTA image generated from the difference between B-scan images IM4 and IM6.

[0065] The OCTA image IMA23 is generated from the difference between two B-scan images with an inter-scan time interval Δt=3×ti, which are B-scan images IM2 and IM5 or B-scan images IM3 and IM6.

[0066] In some embodiments, OCTA image IMA23 is an averaged image of an OCTA image generated from the difference between B-scan images IM2 and IM5, and an OCTA image generated from the difference between B-scan images IM3 and IM6.

[0067] The OCTA image IMA24 is generated from the difference between two B-scan images with an inter-scan time interval Δt=4×ti, which are B-scan images IM2 and IM6.

[0068] The analysis processing device 1100 acquires the above-mentioned OCTA images IMA21 to IMA24 generated sequentially by the OCT device 1200, and generates a VISTA image VMA2 at time t=T2 by analyzing the acquired OCTA images IMA21 to IMA24. The time t=T2 may be the time of the scan timing of any of the OCTA images IMA21 to IMA24 used to generate the VISTA image VMA2, or a statistical value (average value or median value) of the scan timings (times) of the OCTA images IMA21 to IMA24 used to generate the VISTA image VMA2.

[0069] The OCT device 1200 (or the analysis processing device 1100) can similarly sequentially generate four OCTA images (groups of contrast data) at different inter-scan time intervals, and sequentially generate VISTA images from the four generated OCTA images.

[0070] 3 and 4, the time intervals between times t1 and t7 do not have to be equal. In this case, it is possible to acquire multiple OCTA images with non-equidistant inter-scan time intervals from multiple OCT images acquired at times t1 to t7, and analyze the temporal variation of motion contrast intensity according to the non-equidistant inter-scan times of the acquired multiple OCTA images.

[0071] The VISTA processing unit 1121 in FIG. 2 generates a VISTA image from four OCTA images.

[0072] FIG. 5 is a block diagram showing an example of the configuration of the VISTA processing unit 1121 shown in FIG.

[0073] The VISTA processing unit 1121 includes a statistical value calculation unit 1121A, a range adjustment unit 1121B, a luminance information generation unit 1121C, a flow parameter identification unit 1121D, a range adjustment unit 1121E, and a hue information generation unit 1121F. The VISTA processing unit 1121 generates luminance information and hue information for each pixel from the four OCTA images, and generates a single VISTA image by assigning the generated luminance information and hue information to each pixel.

[0074] FIG. 6 is an explanatory diagram of the operation of the VISTA processing unit 1121 in FIG. 5. In FIG. 6, four OCTA images IMA1 to IMA4 correspond to OCTA images IMA11 to IMA14 in FIG. 3 or OCTA images IMA21 to IMA24 in FIG. 4. Pixel position (image area) p1-1 in OCTA image IMA1, pixel position p1-2 in OCTA image IMA2, pixel position p1-3 in OCTA image IMA3, and pixel position p1-4 in OCTA image IMA4 each indicate the same position in a living eye. Note that while FIG. 6 illustrates the process for generating a VISTA image from four OCTA images, the same applies to two, three, or five or more OCTA images.

[0075] The statistical value calculation unit 1121A calculates statistical values ​​of pixel values ​​at pixel positions p1-1 to p1-4 in the four OCTA images IMA1 to IMA4. Specifically, the statistical value calculation unit 1121A calculates statistical values ​​of pixel values ​​at the same pixel position in the four OCTA images IMA1 to IMA4 for each pixel with respect to all pixel positions in the four OCTA images IMA1 to IMA4 (SQ1 in FIG. 6). Examples of statistical values ​​include maximum value, minimum value, median value, mean value, mode value, variance, standard deviation, and values ​​of a predetermined evaluation formula using any of the above statistical values. In this embodiment, the statistical value is the maximum value.

[0076] The range adjustment unit 1121B adjusts the range of the luminance information so that all statistical values ​​of all pixel positions calculated in SQ1 fall within the range, and allocates all predetermined luminance values ​​within the adjusted range (SQ2).

[0077] The luminance information generating unit 1121C generates luminance information for each of all pixel positions in the four OCTA images IMA1 to IMA4 by assigning the statistical values ​​calculated in SQ1 to the luminance values ​​assigned in SQ2 (SQ3).

[0078] Meanwhile, the flow parameter determination unit 1121D determines a flow parameter from the pixel values ​​at pixel positions p1-1 to p1-4 in the four OCTA images IMA1 to IMA4. Here, the flow parameter is a value corresponding to the temporal variation of motion contrast intensity. The flow parameter determination unit 1121D determines a flow parameter for each pixel for all pixel positions in the four OCTA images IMA1 to IMA4 from the pixel values ​​at the same pixel position in the four OCTA images IMA1 to IMA4 (SQ11).

[0079] 7 and 8 are diagrams illustrating the operation of the flow parameter identification unit 1121D in FIG. 5. FIG. 7 shows an example of pixels (or image regions) pa, pb, and pc in an OCTA image IMA. Pixel pa is a pixel in a thick blood vessel region, pixel pc is a pixel in a thin blood vessel region, and pixel pb is a pixel in a blood vessel region that is thinner than the blood vessel region in which pixel pa is located and thicker than the blood vessel region in which pixel pc is located. FIG. 8 schematically shows saturation curves of decorrelation values ​​(decorrelation) in pixels pa, pb, and pc. In FIG. 8, the vertical axis represents the decorrelation value, and the horizontal axis represents the interscan time. In FIG. 8, flow parameters are identified from six OCTA images.

[0080] The decorrelation value corresponds to motion contrast and is a value corresponding to the intensity of the decorrelation signal in the OCTA image. The more rapid the temporal variation of the decorrelation value, the faster the relative blood flow velocity. The more gradual the temporal variation of the decorrelation value, the slower the relative blood flow velocity. The flow parameter specification unit 1121D fits the decorrelation values ​​of corresponding pixels in the multiple OCTA images to the first-order saturation function shown in Equation (1) for each of all pixel positions in the multiple OCTA images. From the first-order saturation function obtained by fitting, the flow parameter specification unit 1121D determines the time constant τ of the first-order saturation function as the saturation time, and specifies the reciprocal of the saturation time (1 / τ) as the flow parameter (SQ11).

[0081]

[0082] In equation (1), t is time and D is the saturation level of the decorrelation value.

[0083] The range adjustment unit 1121E adjusts the range of the hue information so that all flow parameters of all pixel positions identified in SQ11 fall within the range, and allocates all predetermined hue values ​​within the adjusted range (SQ12).

[0084] The hue information generator 1121F generates hue information for each pixel position in the four OCTA images IMA1 to IMA4 by assigning the flow parameters calculated in SQ11 to the hue values ​​assigned in SQ12 (SQ13). The hue information is information for expressing, by hue, that the larger the flow parameter, the faster the relative blood flow velocity, and the smaller the flow parameter, the slower the relative blood flow velocity. For example, based on a predetermined reference relative blood flow velocity, the hue values ​​are assigned so that the hue values ​​corresponding to faster relative blood flow velocities are warmer and the hue values ​​corresponding to slower relative blood flow velocities are cooler.

[0085] In some embodiments, the hue information generator 1121F determines the distribution of all flow parameters determined in SQ11 and determines the mean, median, or mode of the determined distribution as the reference relative blood flow velocity. The hue information generator 1121F generates hue information by assigning hue values ​​to the calculated flow parameters based on the determined reference relative blood flow velocity.

[0086] In some embodiments, the hue information generating unit 1121F generates hue information by assigning the calculated flow parameters to hue values, using a predetermined fixed value as a reference relative blood flow velocity.

[0087] The VISTA processing unit 1121 generates a single VISTA image by assigning the luminance information generated in SQ3 and the hue information generated in SQ13 to each pixel (SQ20).

[0088] The flow parameter analysis unit 1122 in FIG. 2 calculates the time change of the flow parameter generated as described above for each of a group of OCTA images acquired at different times for a specified pixel in an OCTA image or a VISTA image. Here, the group of OCTA images is an example of a group of motion contrast data. For example, the flow parameter analysis unit 1122 can determine the time change of the flow parameter by sequentially determining the flow parameter from the group of OCTA images acquired at times t=T1, T2, ...

[0089] According to the embodiment, a VISTA image of an object to be measured can be acquired using only a B-scan such as a line scan, without performing a three-dimensional OCT scan on the object to be measured. This significantly reduces the amount of data required for VISTA while significantly shortening the measurement time. As a result, it becomes possible to acquire the measurement data required for VISTA in real time, acquire VISTA analysis results in real time, and display the VISTA analysis results on the display device 1300 in real time.

[0090] Furthermore, since VISTA processing can be performed using only B-scans instead of 3D scans, it is possible to repeatedly scan the same location on the object under test, thereby enabling analysis of time-varying changes.

[0091] Furthermore, because VISTA analysis results can be obtained in real time, it is possible to observe in detail the temporal fluctuations in motion contrast intensity in the region of interest while adjusting the interscan time in real time, which is not taken into account in OCTA. For example, the high and low blood flow velocities in a living eye can be depicted as temporal fluctuations in motion contrast intensity. In this case, shortening the interscan time allows for detailed observation of vascular regions with fast blood flow velocities, while lengthening the interscan time allows for detailed observation of vascular regions with slow blood flow velocities.

[0092] The configuration of the analysis system 1000 according to the embodiment is not limited to the configuration shown in FIG.

[0093] 9 is a block diagram showing another example of the configuration of the analysis system according to the embodiment. In FIG. 9, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted where appropriate.

[0094] The analysis system 1000a includes an OCT device 1400 and a display device 1300, and the OCT device 1400 has the functions of the analysis processing device 1100 in the analysis system 1000. Specifically, the OCT device 1400 includes an OCT optical system 1210 and an analysis processing unit 1100a. The OCT optical system 1210 is the OCT optical system included in the OCT device 1200 in FIG. 1 .

[0095] The analysis processing unit 1100a implements the functions of the analysis processing device 1100 of FIG. 1. The analysis processing unit 1100a has a configuration similar to that of the analysis processing device 1100 of FIG. 2. The acquisition unit acquires the detection results of interference light from the OCT optical system 1210 as measurement data and forms an OCT image based on the acquired measurement data. The acquisition unit sequentially forms three or more OCT images based on measurement data obtained by repeatedly performing OCT B-scans on the same cross section of the object to be measured three or more times using the OCT optical system 1210. Furthermore, the acquisition unit generates two or more pieces of motion contrast data (OCTA images) of the cross section at different inter-scan time intervals from the three or more formed OCT images. The analysis unit performs analysis processing to determine the time variation of motion contrast intensity in the cross section based on the two or more pieces of motion contrast data generated by the acquisition unit. The display control unit displays the analysis results obtained by the analysis processing performed by the analysis unit on the display device 1300 in real time.

[0096] According to the analysis system 1000a shown in FIG. 9, the same effects as those of the analysis system 1000 shown in FIG. 1 can be obtained.

[0097] Next, an ophthalmological apparatus having the functions of the ophthalmological information processing apparatus to which the analysis processing apparatus 1100 or the analysis processing unit 1100a according to the embodiment is applied will be specifically described. That is, the ophthalmological information processing apparatus has the functions of the analysis processing apparatus 1100 or the analysis processing unit 1100a according to the embodiment, and the functions of the ophthalmological information processing apparatus are realized by an ophthalmological apparatus capable of performing OCT scans.

[0098] <Ophthalmic Device> An ophthalmic device according to an embodiment includes an ophthalmic imaging device having at least the functionality of an optical coherence tomography. The ophthalmic imaging device included in the ophthalmic device according to some embodiments may be further configured to realize one or more functions of, for example, a fundus camera, a scanning optical ophthalmoscope, a slit lamp ophthalmoscope, a surgical microscope, etc. In addition to the ophthalmic imaging device, the ophthalmic device according to some embodiments includes one or more of an ophthalmic measurement device and an ophthalmic treatment device. The ophthalmic measurement device included in the ophthalmic device according to some embodiments is, for example, one or more of an eye refraction examination device, a tonometer, a specular microscope, a wavefront analyzer, a perimeter, a microperimeter, etc. The ophthalmic treatment device included in the ophthalmic device according to some embodiments is, for example, one or more of a laser treatment device, a surgical device, a surgical microscope, etc.

[0099] In the following embodiments, the ophthalmologic apparatus includes an optical coherence tomography (OCT) scanner and a fundus camera. While the optical coherence tomography scanner employs swept-source OCT, the type of OCT is not limited thereto, and other types of OCT (such as spectral domain OCT, time domain OCT, and amphas OCT) may also be employed.

[0100] Hereinafter, the x direction is defined as a direction perpendicular to the optical axis direction of the objective lens (left-right direction), the y direction is defined as a direction perpendicular to the optical axis direction of the objective lens (up-down direction), and the z direction is defined as the optical axis direction of the objective lens. Note that in the following embodiments, for convenience of explanation, the z direction may refer to the direction opposite to the z direction in FIG. 10 .

[0101] [Configuration] [Optical System] As shown in FIG. 10 , the ophthalmic apparatus 1 according to the embodiment includes a fundus camera unit 2, an OCT unit 100, and an arithmetic and control unit 200. The fundus camera unit 2 includes an optical system and mechanisms for acquiring a front image of the subject's eye E. The OCT unit 100 includes a portion of the optical system and mechanisms for performing OCT. Other portions of the optical system and mechanisms for performing OCT are provided in the fundus camera unit 2. The arithmetic and control unit 200 includes one or more processors for performing various calculations and controls. In addition to these, the ophthalmic apparatus 1 may include optional elements or units such as a member for supporting the subject's face (e.g., a chin rest, a forehead rest, etc.) and a lens unit for switching the target area for OCT (e.g., an anterior segment OCT attachment). Furthermore, the ophthalmic apparatus 1 includes a pair of anterior segment cameras 5A and 5B.

[0102] In some embodiments, the ophthalmic apparatus 1 includes a display device 3. The display device 3 displays processing results (e.g., OCT images) by the arithmetic control unit 200, images obtained by the fundus camera unit 2, operation guidance information for operating the ophthalmic apparatus 1, and the like.

[0103] [Fundus camera unit 2] The fundus camera unit 2 is provided with an optical system for photographing the fundus Ef of the subject's eye E. The acquired image of the fundus Ef (called a fundus image, fundus photograph, etc.) is a front image such as an observed image or a photographed image. The observed image is obtained by video capture using near-infrared light. The photographed image is a still image using flash light. Furthermore, the fundus camera unit 2 can photograph the anterior segment Ea of the subject's eye E to acquire a front image (anterior segment image).

[0104] The fundus camera unit 2 includes an illumination optical system 10 and an imaging optical system 30. The illumination optical system 10 irradiates illumination light onto the subject's eye E. The imaging optical system 30 detects return light of the illumination light from the subject's eye E. The measurement light from the OCT unit 100 is guided to the subject's eye E through an optical path within the fundus camera unit 2, and the return light is guided to the OCT unit 100 through the same optical path.

[0105] Light (observation illumination light) output from an observation light source 11 of the illumination optical system 10 is reflected by a reflecting mirror 12 having a curved reflecting surface, passes through a condenser lens 13, and passes through a visible light cut filter 14 to become near-infrared light. The observation illumination light is then focused near a photographing light source 15, reflected by a mirror 16, and passes through relay lenses 17 and 18, a diaphragm 19, and a relay lens 20. The observation illumination light is then reflected by the peripheral portion (the area surrounding the hole) of a perforated mirror 21, passes through a dichroic mirror 46, and is refracted by an objective lens 22 to illuminate the subject's eye E (fundus Ef or anterior segment Ea). Return light of the observation illumination light from the subject's eye E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through a hole formed in the central region of the perforated mirror 21, passes through a photographing focusing lens 31, and is reflected by a mirror 32. Furthermore, this returning light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the image sensor 35 by the condenser lens 34. The image sensor 35 detects the returning light at a predetermined frame rate. The focus of the photographing optical system 30 is adjusted to coincide with the fundus Ef or the anterior segment Ea.

[0106] Light output from the imaging light source 15 (imaging illumination light) travels the same path as the observation illumination light and is irradiated onto the fundus Ef. Return light of the imaging illumination light from the subject's eye E travels the same path as the return light of the observation illumination light and is guided to the dichroic mirror 33, passes through the dichroic mirror 33, is reflected by a mirror 36, and is focused onto the light-receiving surface of an image sensor 38 by a condenser lens 37.

[0107] The display device 3 displays an image (observation image) based on fundus reflected light detected by the image sensor 35. When the focus of the photographing optical system 30 is adjusted to the anterior segment, an observation image of the anterior segment of the subject's eye E is displayed. The display device 3 also displays an image (photographed image) based on fundus reflected light detected by the image sensor 38. The display device 3 that displays the observation image and the display device 3 that displays the photographed image may be the same or different. When a similar photograph is performed by illuminating the subject's eye E with infrared light, an infrared photographed image is displayed.

[0108] A fixation target and a visual target for visual acuity testing are displayed on an LCD (Liquid Crystal Display) 39. A portion of the light beam output from the LCD 39 is reflected by a half mirror 33A, reflected by a mirror 32, passes through a photographing focusing lens 31, and passes through a hole in the aperture mirror 21. The light beam that has passed through the hole in the aperture mirror 21 passes through a dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef.

[0109] The fixation position of the subject's eye E can be changed by changing the display position of the fixation target on the screen of the LCD 39. Examples of fixation positions include a fixation position for acquiring an image centered on the macula, a fixation position for acquiring an image centered on the optic disc, a fixation position for acquiring an image centered on the fundus center between the macula and the optic disc, and a fixation position for acquiring an image of a region far removed from the macula (periphery of the fundus). The ophthalmologic apparatus 1 according to some embodiments includes a GUI (Graphical User Interface) or the like for specifying at least one of such fixation positions. The ophthalmologic apparatus 1 according to some embodiments includes a GUI or the like for manually moving the fixation position (display position of the fixation target).

[0110] The configuration for presenting a movable fixation target to the subject's eye E is not limited to a display device such as an LCD. For example, a movable fixation target can be generated by selectively illuminating a plurality of light sources in a light source array (such as a light-emitting diode (LED) array). Also, a movable fixation target can be generated by one or more movable light sources.

[0111] The focusing optical system 60 generates a split index used for focus adjustment of the subject's eye E. The focusing optical system 60 moves along the optical path (illumination optical path) of the illumination optical system 10 in conjunction with movement of the imaging focusing lens 31 along the optical path (imaging optical path) of the imaging optical system 30. The reflecting rod 67 is insertable into and removable from the illumination optical path. When performing focus adjustment, the reflective surface of the reflecting rod 67 is tilted relative to the illumination optical path. The focusing light output from the LED 61 passes through the relay lens 62, is split into two beams by the split index plate 63, passes through the two-hole diaphragm 64, is reflected by the mirror 65, and is temporarily imaged and reflected on the reflective surface of the reflecting rod 67 by the condenser lens 66. The focusing light further passes through the relay lens 20, is reflected by the aperture mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef. The fundus reflection light of the focusing light is guided to the image sensor 35 along the same path as the return light of the observation illumination light. Manual focusing and auto focusing can be performed based on the received light image (split target image).

[0112] The dichroic mirror 46 separates the OCT optical path from the fundus imaging optical path. The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for fundus imaging. The OCT optical path (optical path of measurement light) is provided with a collimator lens unit 40, an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, a mirror 44, and a relay lens 45, in this order from the OCT unit 100 side to the dichroic mirror 46 side.

[0113] The optical path length changing unit 41 is movable in the direction of the arrow shown in Fig. 10 to change the length of the OCT optical path. This change in the optical path length is used for correcting the optical path length according to the axial length of the eye, adjusting the interference state, etc. The optical path length changing unit 41 includes a corner cube and a mechanism for moving it.

[0114] The optical scanner 42 is disposed at a position optically conjugate with the pupil of the subject's eye E. The optical scanner 42 deflects the measurement light LS passing through the OCT optical path. The optical scanner 42 is, for example, a galvano scanner capable of two-dimensional scanning.

[0115] The OCT focusing lens 43 is moved along the optical path of the measurement light LS to adjust the focus of the OCT optical system. The movement of the imaging focusing lens 31, the movement of the focus optical system 60, and the movement of the OCT focusing lens 43 can be controlled in a coordinated manner.

[0116] [Anterior Eye Cameras 5A and 5B] The anterior eye cameras 5A and 5B are used to determine the relative position between the optical system of the ophthalmic apparatus 1 and the subject's eye E, similar to the method described in, for example, Japanese Patent Application Laid-Open No. 2013-248376. The anterior eye cameras 5A and 5B are provided on the surface of a housing (such as the fundus camera unit 2) that houses the optical system, facing the subject's eye E. The ophthalmic apparatus 1 determines the three-dimensional relative position between the optical system and the subject's eye E by analyzing two anterior eye images acquired substantially simultaneously from different directions by the anterior eye cameras 5A and 5B. The analysis of the two anterior eye images may be similar to the analysis disclosed in Japanese Patent Application Laid-Open No. 2013-248376. The number of anterior eye cameras may be any number equal to or greater than two.

[0117] In this example, the position of the subject's eye E (i.e., the relative position between the subject's eye E and the optical system) is determined using two or more anterior segment cameras, but the method for determining the position of the subject's eye E is not limited to this. For example, the position of the subject's eye E can be determined by analyzing a front image of the subject's eye E (e.g., an observation image of the anterior segment Ea). Alternatively, a means for projecting a target onto the cornea of ​​the subject's eye E can be provided, and the position of the subject's eye E can be determined based on the projected position of this target (i.e., the detection state of the corneal reflected light beam of this target).

[0118] [OCT Unit 100] As illustrated in Fig. 11 , the OCT unit 100 is provided with an optical system for performing swept-source OCT. This optical system includes an interference optical system. This interference optical system has the following functions: splitting light from a wavelength-variable light source (swept-wavelength light source) into measurement light and reference light; generating interference light by superimposing return light of the measurement light from the subject's eye E on the reference light that has passed through the reference light path; and detecting this interference light. The detection result (detection signal) of the interference light obtained by the interference optical system is a signal indicating the spectrum of the interference light, and is sent to the arithmetic and control unit 200.

[0119] The light source unit 101 includes, for example, a near-infrared wavelength-tunable laser that changes the wavelength of emitted light at high speed. Light L0 output from the light source unit 101 is guided by an optical fiber 102 to a polarization controller 103, where its polarization state is adjusted. The light L0, whose polarization state has been adjusted, is guided by an optical fiber 104 to a fiber coupler 105, where it is split into measurement light LS and reference light LR.

[0120] The reference light LR is guided by an optical fiber 110 to a collimator 111, where it is converted into a parallel beam, and then guided to a corner cube 114 via an optical path length correction member 112 and a dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with the optical path length of the measurement light LS. The dispersion compensation member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS. The corner cube 114 is movable in the incident direction of the reference light LR, thereby changing the optical path length of the reference light LR.

[0121] The reference light LR that has passed through the corner cube 114 passes through a dispersion compensation member 113 and an optical path length correction member 112, is converted from a parallel beam into a convergent beam by a collimator 116, and is then incident on an optical fiber 117. The reference light LR that has entered the optical fiber 117 is guided to a polarization controller 118 where its polarization state is adjusted, is guided by an optical fiber 119 to an attenuator 120 where the light amount is adjusted, and is then guided by an optical fiber 121 to a fiber coupler 122.

[0122] On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and converted into a parallel beam by the collimator lens unit 40, and passes through the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, the mirror 44, and the relay lens 45. The measurement light LS passing through the relay lens 45 is reflected by the dichroic mirror 46, refracted by the objective lens 22, and enters the subject's eye E. The measurement light LS is scattered and reflected at various depth positions in the subject's eye E. The return light of the measurement light LS from the subject's eye E travels the same path as the outward path in the reverse direction and is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128. The incident end of the optical fiber 127, into which the measurement light LS is incident, is positioned approximately conjugate with the fundus Ef of the subject's eye E.

[0123] The fiber coupler 122 generates interference light by combining (causing interference between) the measurement light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121. The fiber coupler 122 splits the interference light at a predetermined splitting ratio (e.g., 1:1) to generate a pair of interference light LC. The pair of interference light LC is guided to the detector 125 via optical fibers 123 and 124, respectively.

[0124] The detector 125 is, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that respectively detect a pair of interference light beams LC, and outputs the difference between the pair of detection results obtained by these photodetectors. The detector 125 sends this output (detection signal) to a DAQ (Data Acquisition System) 130.

[0125] The DAQ 130 is supplied with a clock KC from the light source unit 101. The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength-tunable light source. For example, the light source unit 101 optically delays one of two branched lights obtained by branching light L0 of each output wavelength, and then generates the clock KC based on the result of detecting the combined light. The DAQ 130 samples the detection signal input from the detector 125 based on the clock KC. The DAQ 130 sends the sampling result of the detection signal from the detector 125 to the arithmetic and control unit 200.

[0126] In this example, both an optical path length changer 41 for changing the length of the optical path (measurement optical path, measurement arm) of the measurement light LS and a corner cube 114 for changing the length of the optical path (reference optical path, reference arm) of the reference light LR are provided. However, only one of the optical path length changer 41 and the corner cube 114 may be provided. It is also possible to change the difference between the measurement optical path length and the reference optical path length using optical members other than these.

[0127] [Processing System] Figures 12, 13, and 14 show an example of the configuration of the processing system (control system) of the ophthalmic apparatus 1. Some of the components included in the ophthalmic apparatus 1 are omitted in Figures 12, 13, and 14. Figure 12 shows an example of a functional block diagram of the processing system of the ophthalmic apparatus 1. In Figure 12, parts that are the same as those in Figures 10 and 11 are given the same reference numerals, and descriptions thereof will be omitted as appropriate. Figure 13 shows an example of a functional block diagram of the data processing unit 230 in Figure 12. Figure 14 shows an example of a functional block diagram of the analysis unit 232 in Figure 13.

[0128] The control unit 210, the image forming unit 220, and the data processing unit 230 shown in FIG.

[0129] (Control Unit 210) The control unit 210 executes various controls. The control unit 210 includes a main control unit 211 and a storage unit 212.

[0130] (Main Controller 211) The main controller 211 includes a processor (e.g., a control processor) and controls each part (including each element shown in FIGS. 10 to 14) of the ophthalmologic apparatus 1. For example, the main controller 211 controls each part of the optical system of the fundus camera unit 2 shown in FIGS. 10 and 11 , each part of the optical system of the OCT unit 100, the anterior eye cameras 5A and 5B, the moving mechanism 150 that moves the above-mentioned optical systems, the image forming unit 220, the data processing unit 230, and the user interface (UI) 240.

[0131] The control of the fundus camera unit 2 includes control of the focusing drivers 31A and 43A, control of the image sensors 35 and 38, control of the LCD 39, control of the optical path length changer 41, and control of the optical scanner 42.

[0132] The control of the focusing driver 31A includes control to move the imaging focusing lens 31 in the optical axis direction. The control of the focusing driver 43A includes control to move the OCT focusing lens 43 in the optical axis direction.

[0133] Control of the image sensors 35 and 38 includes control of the light receiving sensitivity of the image pickup elements, control of the frame rate (light receiving timing, exposure time), and control of reading out the light receiving results from the image pickup elements.

[0134] Control of the LCD 39 includes control of the fixation position. For example, the main control unit 211 displays a fixation target at a position on the screen of the LCD 39 that corresponds to a manually or automatically set fixation position. The main control unit 211 can also change (continuously or stepwise) the display position of the fixation target displayed on the LCD 39. This allows the fixation target to be moved (i.e., the fixation position can be changed). The display position and movement pattern of the fixation target are set manually or automatically. Manual setting is performed using, for example, a GUI. Automatic setting is performed by, for example, the data processing unit 230.

[0135] The control over the optical path length changing unit 41 includes control to change the optical path length of the measurement light LS. The main control unit 211 controls a drive unit that drives the corner cube of the optical path length changing unit 41 to move the optical path length changing unit 41 along the optical path of the measurement light LS and change the optical path length of the measurement light LS.

[0136] The control of the optical scanner 42 includes control of the scan mode, the scan range including the scan position (scan start position, scan end position), the scan speed, etc. By controlling the optical scanner 42, the main controller 211 can perform an OCT scan with the measurement light LS on a desired region in the measurement region (image capture region).

[0137] The main control unit 211 can also control the observation light source 11, the imaging light source 15, the focus optical system 60, and the like.

[0138] The control of the OCT unit 100 includes control of the light source unit 101, control of the reference driver 114A, control of the detector 125, and control of the DAQ 130.

[0139] Control of the light source unit 101 includes control of turning the light source on and off, control of the amount of light emitted from the light source, control of the wavelength sweep range, control of the wavelength sweep speed, and control of the emission timing of light of each wavelength component.

[0140] The control over the reference driver 114A includes control to change the optical path length of the reference light LR. The main controller 211 controls the reference driver 114A to move the corner cube 114 along the optical path of the reference light LR, thereby changing the optical path length of the reference light LR.

[0141] Control of the detector 125 includes control of the light receiving sensitivity of the detection elements, control of the frame rate (light receiving timing), and control of reading out the light receiving results of the detection elements.

[0142] The control of the DAQ 130 includes control of capturing the detection results of the interference light obtained by the detector 125 (capture timing, sampling timing), and control of reading out the interference signal corresponding to the detection results of the captured interference light.

[0143] Control of the anterior eye cameras 5A and 5B includes control of the light receiving sensitivity of each camera, control of the frame rate (light receiving timing), and synchronization control of the anterior eye cameras 5A and 5B.

[0144] The movement mechanism 150, for example, moves at least the fundus camera unit 2 (optical system) three-dimensionally. In a typical example, the movement mechanism 150 includes at least a mechanism for moving the fundus camera unit 2 in the x direction (left-right direction), a mechanism for moving it in the y direction (up-down direction), and a mechanism for moving it in the z direction (depth direction, front-back direction). The mechanism for movement in the x direction includes, for example, an x-stage movable in the x direction and an x-movement mechanism for moving the x-stage. The mechanism for movement in the y direction includes, for example, a y-stage movable in the y direction and a y-movement mechanism for moving the y-stage. The mechanism for movement in the z direction includes, for example, a z-stage movable in the z direction and a z-movement mechanism for moving the z-stage. Each movement mechanism includes a pulse motor as an actuator and operates under the control of the main control unit 211.

[0145] Control of the moving mechanism 150 is used for alignment and tracking. Tracking refers to moving the device optical system in accordance with the eye movement of the subject's eye E. When tracking is performed, alignment and focus adjustment are performed beforehand. Tracking is a function of maintaining a suitable positional relationship where alignment and focus are achieved by making the position of the device optical system follow the eye movement. In some embodiments, the moving mechanism 150 is configured to be controlled to change the optical path length of the reference light (and therefore the optical path length difference between the optical path of the measurement light and the optical path of the reference light).

[0146] In the case of manual alignment, the user operates the UI 240 to cancel the displacement of the subject's eye E relative to the optical system, thereby moving the optical system relative to the subject's eye E. For example, the main control unit 211 controls the movement mechanism 150 by outputting a control signal corresponding to the operation content on the UI 240 to the movement mechanism 150, thereby moving the optical system relative to the subject's eye E.

[0147] In the case of auto-alignment, the main controller 211 controls the moving mechanism 150 by outputting a control signal to the moving mechanism 150 so that displacement of the subject's eye E relative to the optical system is canceled, thereby moving the optical system relative to the subject's eye E. Specifically, trigonometry-based calculation processing is performed based on the positional relationship between the pair of anterior eye cameras 5A and 5B and the subject's eye E, and the main controller 211 controls the moving mechanism 150 so that the positional relationship of the subject's eye E relative to the optical system is a predetermined positional relationship. Such control is disclosed, for example, in Japanese Patent Application Laid-Open No. 2013-248376. In some embodiments, the main controller 211 controls the moving mechanism 150 so that the optical axis of the optical system substantially coincides with the axis (visual axis) of the subject's eye E and the distance of the optical system from the subject's eye E is a predetermined working distance, thereby moving the optical system relative to the subject's eye E. Here, the working distance is a predetermined value also called the working distance of the objective lens 22, and corresponds to the distance between the subject's eye E and the optical system during measurement (photography) using the optical system.

[0148] The main controller 211 also includes a display controller 211A. The display controller 211A is capable of displaying various types of information on the display unit 240A. For example, the display controller 211A causes the display unit 240A to display a fundus image or an anterior segment image acquired using the fundus camera unit 2, an OCT image or an OCTA image acquired using the OCT unit 100, and data processing results acquired by the data processor 230 (described later). Examples of OCT images acquired using the OCT unit 100 include B-scan images, projection images, and en-face images. Examples of data processing results acquired by the data processor 230 include VISTA analysis results, VISTA images, and images showing changes in flow parameters over time. In some embodiments, the display controller 211A causes the display unit 240A to display the data processing results in association with at least one of the fundus image (or anterior segment image) and the OCT image.

[0149] (Storage unit 212) The storage unit 212 stores various types of data. The functions of the storage unit 212 are realized by a storage device such as a memory or a storage device. Examples of data stored in the storage unit 212 include image data of fundus images, image data of anterior segment images, OCT data (including OCT images), OCTA data (motion contrast data), VISTA analysis results, and information about the subject's eye. The information about the subject's eye includes information about the subject, such as patient ID and name, identification information for the left eye / right eye, and electronic medical record information. The storage unit 212 stores programs for executing various processors (control processor, image formation processor, data processing processor).

[0150] (Image Forming Unit 220) The image forming unit 220 includes a processor (e.g., an image forming processor) and forms an OCT image of the subject's eye E based on the output (sampling results of the detection signals) from the DAQ 130. For example, similar to conventional swept-source OCT, the image forming unit 220 performs signal processing on the spectral distribution based on the sampling results for each A-line to form a reflection intensity profile for each A-line, and then images these A-line profiles and arranges them along the scan line. The signal processing includes noise removal (noise reduction), filtering, FFT (Fast Fourier Transform), etc. When performing other types of OCT, the image forming unit 220 performs known processing depending on the type.

[0151] (Data Processing Unit 230) The data processing unit 230 includes a processor (for example, a data processor) and performs image processing and analysis processing on the image formed by the image forming unit 220. At least two of the processor included in the main control unit 211, the processor included in the data processing unit 230, and the processor included in the image forming unit 220 may be configured by a single processor.

[0152] The data processing unit 230 performs known image processing, such as interpolation processing that interpolates pixels between tomographic images, to form image data of a three-dimensional image of the fundus oculi Ef or the anterior segment Ea. Note that image data of a three-dimensional image refers to image data in which pixel positions are defined using a three-dimensional coordinate system. Image data of a three-dimensional image includes image data consisting of three-dimensionally arranged voxels. This image data is called volume data or voxel data. When displaying an image based on the volume data, the data processing unit 230 performs rendering processing (such as volume rendering or MIP (Maximum Intensity Projection)) on the volume data to form image data of a pseudo three-dimensional image as viewed from a specific line of sight. This pseudo three-dimensional image is displayed on a display device, such as the display unit 240A.

[0153] It is also possible to form stack data of multiple tomographic images as image data of a three-dimensional image. Stack data is image data obtained by arranging multiple tomographic images obtained along multiple scan lines in a three-dimensional manner based on the positional relationship of the scan lines. In other words, stack data is image data obtained by expressing multiple tomographic images originally defined by individual two-dimensional coordinate systems using a single three-dimensional coordinate system (i.e., embedding them in a single three-dimensional space).

[0154] In some embodiments, the data processing unit 230 generates a B-scan image by arranging the A-scan images in the B-scan direction. In some embodiments, the data processing unit 230 can perform various rendering operations on the acquired three-dimensional dataset (volume data, stack data, etc.) to generate a B-mode image (B-scan image) (longitudinal or axial image) in an arbitrary cross section, a C-mode image (C-scan image) (transverse or horizontal image) in an arbitrary cross section, a projection image, a shadowgram, etc. An image of an arbitrary cross section, such as a B-scan image or a C-scan image, is generated by selecting pixels (voxels) on a specified cross section from the three-dimensional dataset. A projection image is generated by projecting the three-dimensional dataset in a predetermined direction (z direction, depth direction, axial direction). A shadowgram is generated by projecting a portion of the three-dimensional dataset (e.g., partial data corresponding to a specific layer) in a predetermined direction. By changing the depth range in the layer direction to be integrated, two or more different shadowgrams can be generated. An image viewed from the front side of the subject's eye, such as a C-scan image, a projection image, or a shadowgram, is called an en-face image.

[0155] Furthermore, the data processing unit 230, as a three-dimensional calculation unit, is capable of determining the three-dimensional position of the subject's eye E based on the positions of the anterior eye cameras 5A and 5B and the positions of the characteristic parts.

[0156] At this time, the data processing unit 230, as a characteristic portion identification unit, first analyzes each captured image obtained by the anterior eye cameras 5A and 5B to identify a position in the captured image corresponding to a characteristic portion of the anterior eye Ea (referred to as a characteristic portion). Examples of characteristic portions include the pupil region of the subject's eye E, the pupil center position of the subject's eye E, the pupil centroid position, the corneal center position, the corneal apex position, the center position of the subject's eye, or the iris. For example, the data processing unit 230 identifies the image region (pupil region) corresponding to the pupil of the subject's eye E based on the distribution of pixel values ​​(such as brightness values) of the captured image.

[0157] Next, the data processing unit 230 identifies the center position of the identified pupil region. Because the pupil is approximately circular as described above, the outline of the pupil region can be identified, and the center position of this outline (an approximate circle or ellipse) can be identified and used as the pupil center position. Alternatively, the center of gravity of the pupil region can be calculated, and this center position can be identified as the pupil center position. The data processing unit 230 can sequentially identify characteristic positions corresponding to characteristic parts in the images sequentially acquired by the anterior eye cameras 5A and 5B. Note that the data processing unit 230 may identify characteristic positions every other arbitrary number of frames (one or more) in the images sequentially acquired by the anterior eye cameras 5A and 5B.

[0158] The data processing unit 230 then functions as a three-dimensional position calculation unit and identifies the three-dimensional position of the characteristic portion as the three-dimensional position of the subject's eye E based on the positions of the anterior-segment cameras 5A and 5B and the characteristic position corresponding to the identified characteristic portion. The data processing unit 230 calculates the three-dimensional position of the subject's eye E by applying known trigonometry to the positions (known) of the two anterior-segment cameras 5A and 5B and the positions corresponding to the characteristic portion in the two captured images. The determined three-dimensional position is sent to the main control unit 211. The main control unit 211 controls the movement mechanism 150 based on the determined three-dimensional position to move the optical system relative to the subject's eye E, thereby aligning the optical system with the subject's eye E. That is, the main control unit 211 controls the movement mechanism 150 based on the determined three-dimensional position so that the positions of the optical axis of the optical system in the x and y directions coincide with the positions of the three-dimensional position in the x and y directions and so that the distance in the z direction is a predetermined working distance.

[0159] As shown in FIG. 13, the data processing unit 230 further includes an OCTA image generating unit 231 and an analyzing unit 232 .

[0160] The OCTA image generating unit 231 can generate an OCTA image (a vessel-enhanced image, an angiogram) in which retinal blood vessels and choroidal blood vessels are emphasized based on data (e.g., B-scan data) collected in time series by OCT scanning. The OCTA image may be a tomographic image or a frontal image.

[0161] In some embodiments, the OCTA image generating unit 231 compares two B-scan images obtained by repeatedly performing B-scans on approximately the same part of the subject's eye E, and constructs an enhanced image (motion contrast image) in which the changed part is emphasized by converting pixel values ​​of the changed part in signal intensity into pixel values ​​corresponding to the changed part. In addition, the data processing unit 230 can form an OCTA (angiography) image by extracting information of a predetermined thickness at a desired part from the constructed multiple enhanced images and constructing it as an en-face image.

[0162] In this embodiment, the OCTA image generation unit 231 generates two or more OCTA images of cross sections at different inter-scan time intervals obtained by repeatedly performing B-scans three or more times on the same cross section of the test eye E (e.g., the fundus Ef).

[0163] The analysis unit 232 has the functions of the analysis unit 1120 in Fig. 2. That is, the analysis unit 232 executes VISTA processing using two or more OCTA images with different inter-scan time intervals generated by the OCTA image generation unit 231, and also identifies flow parameters and determines changes in the flow parameters over time.

[0164] As shown in FIG. 14, the analysis unit 232 includes a VISTA processing unit 232A and a flow parameter analysis unit 232B.

[0165] The VISTA processing unit 232A has the functions of the VISTA processing unit 1121 in FIG. 2 . That is, the VISTA processing unit 232A has a configuration similar to that of the VISTA processing unit 1121 shown in FIG. 5 . The VISTA processing unit 232A performs VISTA processing using two or more OCTA images generated by the OCTA image generating unit 231 to identify temporal fluctuations in motion contrast intensity in a cross section. The VISTA processing unit 232A can generate a VISTA image representing the distribution of the identified temporal fluctuations in motion contrast intensity as an analysis result. Specifically, the VISTA processing unit 232A generates an image representing the temporal fluctuations in motion contrast intensity based on the saturation times of the motion contrast intensity at each of multiple positions in a cross section of a measurement site (e.g., the fundus Ef) of the subject's eye E.

[0166] The flow parameter analysis unit 232B has the functions of the flow parameter analysis unit 1122 in FIG. 2 . That is, the flow parameter analysis unit 232B generates information representing the time change of the time change of the motion contrast intensity at a specified position on a cross section where OCT scans are repeatedly performed. Specifically, the flow parameter analysis unit 1122 identifies, as flow parameters, the time change of the motion contrast intensity at the same specified position on each of two or more VISTA images acquired at different times. Furthermore, the flow parameter analysis unit 1122 generates information representing the time change of the identified flow parameters.

[0167] Furthermore, the analysis unit 232 performs a predetermined analysis process using the detection result of the interference light LC, the OCT image, or the OCTA image.

[0168] For example, the analyzer 232 analyzes the detection result of the interference light LC, the OCT image, or the OCTA image, and outputs an evaluation value (including a statistical value of the evaluation value) corresponding to the image quality (signal-to-noise ratio) of the OCT image or the OCTA image as the analysis result. The main controller 211 can control at least one of the focusing driver 43A, the optical path length changer 41, and the polarization controllers 103 and 118 based on the analysis result obtained by the analyzer 232.

[0169] For example, the analysis unit 232 analyzes the detection results of the interference light LC obtained by OCT measurement to determine the focus state of the measurement light LS in the focus fine adjustment control. For example, the main control unit 211 repeatedly performs OCT measurement while controlling the focus driver 43A according to a predetermined algorithm. The analysis unit 232 calculates a predetermined evaluation value related to the image quality of the OCT image (or OCTA image) by analyzing the detection results of the interference light LC repeatedly obtained by OCT measurement. The analysis unit 232 determines whether the calculated evaluation value is equal to or less than a threshold. In some embodiments, the focus fine adjustment is continued until the calculated evaluation value is equal to or less than the threshold. In other words, when the evaluation value is equal to or less than the threshold, it is determined that the focus state of the measurement light LS is appropriate, and the focus fine adjustment is continued until it is determined that the focus state of the measurement light LS is appropriate.

[0170] In some embodiments, the main controller 211 repeatedly performs OCT measurement as described above to acquire interference signals, while monitoring the intensity (interference intensity, interference sensitivity) of the successively acquired interference signals. Furthermore, while performing this monitoring process, the main controller 211 moves the OCT focusing lens 43 to search for the position of the OCT focusing lens 43 where the interference intensity is maximized. By performing such fine focus adjustment, the OCT focusing lens 43 can be guided to a position where the interference intensity is optimized.

[0171] The analyzer 232 also analyzes the detection results of the interference light LC obtained by the OCT measurement to determine the polarization state of at least one of the measurement light LS and the reference light LR. For example, the main controller 211 repeatedly performs OCT measurement while controlling at least one of the polarization controllers 103 and 118 according to a predetermined algorithm. In some embodiments, the main controller 211 controls the attenuator 120 to change the attenuation amount of the reference light LR. The analyzer 232 calculates a predetermined evaluation value related to the image quality of the OCT image (or OCTA image) by analyzing the detection results of the interference light LC repeatedly obtained by the OCT measurement. The analyzer 232 determines whether the calculated evaluation value is equal to or less than a threshold value. This threshold value is set in advance. The polarization adjustment is continued until the calculated evaluation value is equal to or less than the threshold value. In other words, when the evaluation value is equal to or less than the threshold value, it is determined that the polarization state of the measurement light LS is appropriate, and the polarization adjustment is continued until it is determined that the polarization state of the measurement light LS is appropriate.

[0172] In some embodiments, the main controller 211 can also monitor the interference strength during polarization adjustment.

[0173] Furthermore, the analysis unit 232 can perform predetermined analytical processing on OCT images or OCTA images. Analytical processing on OCT images includes identifying predetermined regions (tissues, lesions) in the subject's eye E; calculating the distance (interlayer distance), area, angle, ratio, and density between specified regions; performing calculations using specified formulas; identifying the shape of the predetermined regions; calculating statistical values ​​of these; calculating the distribution of measured values ​​and statistical values; and image processing based on the results of these analytical processing. Predetermined tissues include blood vessels, the optic disc, the fovea, and the macula. Predetermined lesions include white spots and hemorrhage. Predetermined analytical processing on OCTA images includes identifying vascular walls, identifying vascular regions, identifying the connection relationship between two or more vascular regions, identifying the distribution of vascular regions, identifying blood flow, calculating blood flow velocity, and determining whether the vascular region is an artery or a vein.

[0174] 12, the user interface 240 includes a display unit 240A and an operation unit 240B. The display unit 240A includes the display device 3. The operation unit 240B includes various operation devices and input devices.

[0175] The user interface 240 may include a device that combines a display function and an operation function, such as a touch panel. In other embodiments, at least a portion of the user interface may not be included in the ophthalmic apparatus. For example, the display device may be an external device connected to the ophthalmic apparatus.

[0176] (Communication Unit 280) The communication unit 280 shown in FIG. 12 has a function for communicating with an external device (not shown). The communication unit 280 has a communication interface corresponding to the connection form with the external device. Examples of external devices include a server device, an OCT device, a scanning optical ophthalmoscope, a slit lamp ophthalmoscope, an ophthalmic measurement device, and an ophthalmic treatment device. Examples of ophthalmic measurement devices include an eye refraction examination device, a tonometer, a specular microscope, a wavefront analyzer, a perimeter, and a microperimeter. Examples of ophthalmic treatment devices include a laser treatment device, a surgical device, and a surgical microscope. The external device may also be a device (reader) that reads information from a recording medium or a device (writer) that writes information to a recording medium. Furthermore, the external device may also be a hospital information system (HIS) server, a DICOM (Digital Imaging and Communication in Medicine) server, a doctor's terminal, a mobile terminal, a personal terminal, a cloud server, etc.

[0177] The arithmetic and control unit 200 (control unit 210, image forming unit 220, and data processing unit 230) is an example of an "analysis processing device" according to the embodiment. The optical system from the objective lens 22 to the OCT unit 100 shown in FIG. 10 is an example of an "OCT optical system" according to the embodiment. The OCTA image is an example of "motion contrast data" according to the embodiment. The VISTA image is an example of an "image representing temporal variation in motion contrast intensity" according to the embodiment. The display unit 240A (display device 3) is an example of a "display means" according to the embodiment.

[0178] (Operation) An example of the operation of the ophthalmologic apparatus 1 according to the embodiment will be described.

[0179] 15 to 17 show an example of operation of the ophthalmic apparatus 1 according to the embodiment. FIG. 15 shows a flow diagram of the example of operation of the ophthalmic apparatus 1. FIG. 16 shows a flow diagram of the example of operation of the ophthalmic apparatus 1 performing the processing of step S17 in FIG. 15. FIG. 17 shows a flow diagram of the example of operation of the ophthalmic apparatus 1 performing the processing of step S20 in FIG. 15. The storage unit 212 stores a computer program for realizing the processing shown in FIGS. 15 to 17. The main control unit 211 operates in accordance with this computer program to execute the processing shown in FIGS. 15 to 17.

[0180] (S11: Alignment) First, the main control unit 211 executes alignment.

[0181] For example, the main controller 211 controls the LCD 39 to present a fixation target for alignment to the subject's eye E. The main controller 211 controls the anterior eye cameras 5A and 5B to substantially simultaneously capture images of the anterior eye Ea of the subject's eye E. Under control of the main controller 211, the data processor 230 analyzes the pair of anterior eye images acquired substantially simultaneously by the anterior eye cameras 5A and 5B, and identifies the position of the pupil center of the subject's eye E as a characteristic site. The data processor 230 determines the three-dimensional position of the subject's eye E by calculation using trigonometry based on the positional relationship between the pair of anterior eye cameras 5A and 5B and the subject's eye E.

[0182] The main control unit 211 controls the moving mechanism 150 based on the three-dimensional position of the subject's eye E obtained by the data processing unit 230 so that a predetermined positional relationship is established between the optical system (e.g., the fundus camera unit 2) and the subject's eye E. Here, the predetermined positional relationship is a positional relationship that allows imaging and examination of the subject's eye E using the optical system.

[0183] (S12: Start of tracking) Subsequently, the main control unit 211 starts tracking.

[0184] For example, the main controller 211 controls the moving mechanism 150 so that a predetermined positional relationship between the subject's eye E and the optical system is maintained by the alignment performed in step S11. In some embodiments, the main controller 211 starts tracking control by controlling the moving mechanism 150 based on an anterior eye image acquired by the anterior eye camera 5A or 5B. This tracking control continues until the OCTA measurement is completed.

[0185] (S13: Setting Scan Conditions) Next, the main controller 211 sets scan conditions for the OCT scan in the storage unit 212. The main controller 211 controls the optical scanner 42 in accordance with the scan conditions set in the storage unit 212 to perform the OCT scan.

[0186] Examples of the scan conditions include a scan mode, a scan range including a scan position (scan start position, scan end position), a scan speed, an interscan time, the number of scan repetitions for executing VISTA processing, etc. In this embodiment, the line scan mode is set as the scan mode.

[0187] (S14: Obtaining an adjustment tomographic image) The main controller 211 displays a fixation target for OCT measurement at a predetermined position on the LCD 39. The main controller 211 can display the fixation target at a display position on the LCD 39 that corresponds to the position of the optical axis of the optical system in the fundus oculi Ef.

[0188] Next, the main controller 211 controls the OCT unit 100 to perform OCT provisional measurement and acquire an adjustment tomographic image for adjusting the reference position of the measurement range in the depth direction. Specifically, the main controller 211 controls the optical scanner 42 to deflect the measurement light LS generated based on the light L0 emitted from the light source unit 101 and scan the fundus Ef of the subject's eye E with the deflected measurement light LS. The detection result of the interference light obtained by scanning the measurement light LS is sampled in synchronization with the clock KC and then sent to the image forming unit 220. The image forming unit 220 forms a tomographic image (OCT image) of the subject's eye E from the obtained interference signal.

[0189] (S15: Adjusting the reference position in the depth direction) Next, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction).

[0190] For example, the main controller 211 causes the data processor 230 to identify a predetermined region (e.g., the sclera) in the tomographic image obtained in step S14, and sets a position a predetermined distance in the depth direction from the position of the identified predetermined region as the reference position of the measurement range. The main controller 211 controls at least one of the optical path length changers 41 and 114 in accordance with the reference position. Alternatively, a predetermined position may be set as the reference position of the measurement range so that the optical path lengths of the measurement light LS and the reference light LR are approximately the same.

[0191] (S16: Focus Adjustment, Polarization Adjustment) Next, the main controller 211 executes focus adjustment control and polarization adjustment control.

[0192] For example, the main controller 211 controls the focus driver 43A to move the OCT focusing lens 43 by a predetermined distance, and then controls the OCT unit 100 to perform OCT measurement. As described above, the main controller 211 causes the data processor 230 to determine the focus state of the measurement light LS based on the detection result of the interference light obtained by the OCT measurement. When it is determined that the focus state of the measurement light LS is not appropriate based on the determination result by the data processor 230, the main controller 211 controls the focus driver 43A again, and repeats this process until it is determined that the focus state is appropriate.

[0193] Furthermore, for example, the main control unit 211 controls at least one of the polarization controllers 103, 118 to change the polarization state of at least one of the light L0 and the measurement light LS by a predetermined amount, and then controls the OCT unit 100 to perform OCT measurement. The main control unit 211 causes the image forming unit 220 to form an OCT image based on the detection result of the acquired interference light. As described above, the main control unit 211 causes the data processing unit 230 to determine the image quality of the OCT image obtained by the OCT measurement. When it is determined based on the determination result by the data processing unit 230 that the polarization state of the measurement light LS is not appropriate, the main control unit 211 again controls the polarization controllers 103, 118, and repeats this process until it is determined that the polarization state is appropriate.

[0194] In some embodiments, step S13 is performed after steps S14 and S15.

[0195] (S17: OCT Measurement) Next, with the optical system set in steps S14 and S15, the main controller 211 controls the OCT unit 100 and the like according to the scan conditions set in step S13. As a result, line scans are repeatedly performed on the fundus Ef at predetermined inter-scan time intervals. That is, multiple OCT data are obtained for the same cross section of the fundus Ef at predetermined inter-scan time intervals. Details of step S17 will be described later.

[0196] (S18: Forming OCT Images) Next, the main controller 211 controls the image forming unit 220 to sequentially form B-scan images (OCT images) based on each of the multiple OCT data obtained in step S17. As a result, for example, B-scan images IM1 to IM7 shown in FIG. 3 or FIG. 4 are sequentially formed.

[0197] In some embodiments, steps S17 and S18 are performed in parallel.

[0198] (S19: Generate OCTA images) Next, the main controller 211 controls the OCTA image generator 231 to generate multiple OCTA images of cross sections at different inter-scan time intervals from the multiple OCT images formed in step S18. This results in multiple OCTA image groups being acquired. Of the multiple OCTA image groups, a first OCTA image group includes, for example, OCTA images IMA11 to IMA14 shown in FIG. 3, and a second OCTA image group includes, for example, OCTA images IMA21 to IMA24 shown in FIG. 4.

[0199] (S20: VISTA Processing) Subsequently, the main control unit 211 controls the analysis unit 232 to execute VISTA processing using the multiple OCTA images generated in step S19.

[0200] The VISTA processing unit 232A performs VISTA processing using the multiple OCTA images generated in step S19 to identify temporal variations in motion contrast intensity in the cross section. The VISTA processing unit 232A generates, as an analysis result, a VISTA image (e.g., the VISTA image VMA1 shown in FIG. 3 or the VISTA image VMA2 shown in FIG. 4) that represents the distribution of the identified temporal variations in motion contrast intensity. Furthermore, the flow parameter analysis unit 232B identifies temporal variations in the flow parameters identified by the VISTA processing unit 232A and generates information representing the temporal variations in the flow parameters. Details of step S20 will be described later.

[0201] This completes the operation of the ophthalmologic apparatus 1 (END).

[0202] The processing of step S17 in FIG. 15 is executed for the same cross section of the fundus oculi Ef according to the flow shown in FIG.

[0203] (S21: OCT Scan) In step S17 of FIG. 15, first, the main controller 211 controls the OCT unit 100 and the like in accordance with the scan conditions set in step S13 to perform a single line scan on the fundus Ef.

[0204] (S22: Predetermined number of repetitions?) Next, the main controller 211 determines whether the number of times the OCT scan in step S21 was repeatedly performed on the same cross section of the fundus oculi Ef exceeds the predetermined number of repetitions under the scan conditions set in step S13.

[0205] When it is determined that the number of times the OCT scan has been repeatedly executed in step S21 exceeds the predetermined number of times of repetition of the scan conditions (S22: Y), the process of step S17 ends (END). On the other hand, when it is determined that the number of times the OCT scan has been repeatedly executed in step S21 does not exceed the predetermined number of times of repetition of the scan conditions (S22: N), the process of step S17 proceeds to step S23.

[0206] (S23: Has the interscan time elapsed?) In step S22, when it is determined that the number of times the OCT scan was repeatedly performed in step S21 does not exceed the specified number of repetitions of the scan conditions (S22: N), the main control unit 211 determines whether the interscan time has elapsed.

[0207] That is, the main controller 211 determines whether or not the inter-scan time of the scan conditions set in step S13 has elapsed from the scan timing of the OCT scan executed in the immediately preceding step S21.

[0208] If it is determined that the interscan time has elapsed (S23: Y), the process of step S17 proceeds to step S21. On the other hand, if it is determined that the interscan time has not elapsed (S23: N), the process of step S17 continues with the process of step S23.

[0209] As described above, the process of step S17 in FIG. 15 is executed.

[0210] The process of step S20 in FIG. 15 is executed according to the flow shown in FIG.

[0211] (S31: Generate VISTA Image) The analysis unit 232 generates a VISTA image in the same manner as the VISTA processing unit 1121, following the flow shown in FIG.

[0212] 6, the VISTA processing unit 232A functions as a statistical value calculation unit, calculating the maximum pixel value for each corresponding pixel in the multiple OCTA images generated in step S19. Furthermore, the VISTA processing unit 232A functions as a range adjustment unit, adjusting the range of luminance information, and functions as a luminance information generation unit, generating luminance information by assigning the calculated maximum pixel value to a luminance value within the range for each corresponding pixel.

[0213] 6, the VISTA processing unit 232A, as a flow parameter specifying unit, specifies a flow parameter for each corresponding pixel based on the multiple OCTA images generated in step S19. Furthermore, the VISTA processing unit 232A, as a range adjusting unit, adjusts the range of hue information, and as a hue information generating unit, generates hue information by assigning the specified flow parameter to a hue value within the range for each corresponding pixel.

[0214] The VISTA processing unit 232A generates a single VISTA image by assigning the generated luminance information and the generated hue information to each pixel.

[0215] (S32: Temporal Analysis of Flow Parameters) Next, the flow parameter analysis unit 232B identifies temporal changes in the multiple flow parameters identified at the designated pixel for each group of OCTA images acquired at different times in step S19. The flow parameter analysis unit 232B generates information representing the temporal changes in the flow parameters.

[0216] For example, when identifying the flow parameters at a pixel of interest, the flow parameter analysis unit 232B performs a weighted average of pixels within a region designated by the user using the OCTA data of corresponding pixels in the flow parameter image (VISTA image, image of time variation of motion contrast intensity obtained by the VISTA processing unit 232A). This makes it possible to analyze with high precision the time variation of the variation of motion contrast at the pixel of interest without being affected by the surrounding pixels of the pixel of interest, where the motion contrast intensity does not vary.

[0217] (S33: Display) Next, the display control unit 211A causes the display unit 240A to display the VISTA image generated in step S31 and the information representing the time change of the flow parameter generated in step S32.

[0218] As described above, the process of step S20 in FIG. 15 is executed.

[0219] FIG. 18 is a schematic diagram showing an example of a display on the display unit 240A in step S33.

[0220] The display control unit 211A displays an image representing the analysis result obtained by the VISTA processing unit 232A in an analysis result display area D1 on the display screen of the display unit 240A. The analysis result display area D1 includes a tomographic image display area D2, a live image display area D3, a flow parameter analysis result display area D4, and a scan parameter adjustment instruction area D5.

[0221] The tomographic image display area D2 displays the VISTA image generated in step S31, etc. In this embodiment, an OCT image display switching object D21, an OCTA image display switching object D22, and a VISTA image display switching object D23 are displayed in the tomographic image display area D2. When the user operates the operation unit 240B to specify a display switching object on the display screen, the display control unit 211A displays an image of the type corresponding to the specified display switching object in the tomographic image display area D2.

[0222] For example, when a user operates the operation unit 240B to move a cursor on the display screen and perform a click operation, the main control unit 211 determines whether the cursor position where the click operation was performed is in the display area of ​​a display switching object. When it is determined that the cursor position is in the display area, the main control unit 211 identifies the type of the specified display switching object. The display control unit 211A displays an image corresponding to the identified type of display switching object in the tomographic image display area D2.

[0223] Specifically, when an OCT image display switching object D21 is specified by an operation on the operation unit 240B, the display control unit 211A displays the OCT image used to generate the VISTA image in the tomographic image display area D2. The OCT image is, for example, one of the B-scan images IM1 to IM5 (B-scan images IM2 to IM6). In some embodiments, the OCT image displayed in the tomographic image display area D2 can be further switched from among the B-scan images IM1 to IM5 (B-scan images IM2 to IM6) by an operation on the operation unit 240B.

[0224] When the OCTA image display switching object D22 is specified by an operation on the operation unit 240B, the display control unit 211A displays the OCTA image used to generate the VISTA image in the tomographic image display area D2. The OCTA image is, for example, one of the OCTA images IMA11 to IMA14 (OCTA images IMA21 to IMA24). In some embodiments, the OCTA image displayed in the tomographic image display area D2 can be further switched from among the OCTA images IMA11 to IMA14 (OCTA images IMA21 to IMA24) by an operation on the operation unit 240B.

[0225] When the VISTA image display switching object D23 is designated by an operation on the operation unit 240B, the display control unit 211A displays a VISTA image in the tomographic image display area D2. The VISTA image is, for example, a VISTA image VMA1 (VISTA image VMA2).

[0226] Here, the B-scan image, OCTA image, and VISTA image displayed in the tomographic image display area D2 are already aligned with each other without the need for alignment. Therefore, by simply specifying the display switching object, it becomes possible to easily observe the morphology in the B-scan image corresponding to the region of interest in the VISTA image and the motion contrast in the OCTA image.

[0227] The live image display area D3 displays a projection image of the fundus Ef, an en-face image, or an observation image of the fundus Ef (or the anterior segment Ea) obtained by the imaging optical system 30. For example, it is possible to superimpose an image indicating the scan position (scan range) on the live image displayed in the live image display area D3.

[0228] For example, the pixel value of each pixel in the projection image or en-face image is the average or maximum value of the pixel values ​​in the depth direction. At this time, the data processing unit 230 generates the projection image or en-face image by performing a weighted average for each pixel using the OCTA data of the corresponding pixel in the flow parameter image. This makes it possible to depict the vascular structure of a specified layer region in detail without being affected by regions other than the vascular region.

[0229] The pixel positions in the image displayed in the tomographic image display area D2 correspond to the pixel positions in the live image displayed in the live image display area D3. Therefore, when the user uses the operation unit 240B to specify a pixel position in the image displayed in the tomographic image display area D2, the display control unit 211A can identifiably display the pixel position of the corresponding pixel in the live image. Also, when the user uses the operation unit 240B to specify a pixel position in the live image displayed in the live image display area D3, the display control unit 211A can identifiably display the pixel position of the corresponding pixel in the image displayed in the tomographic image display area D2.

[0230] The flow parameter analysis result display area D4 displays information representing time changes in flow parameters. An example of information representing time changes in flow parameters is a time change graph in which the vertical axis represents flow parameters and the horizontal axis represents time.

[0231] The scan parameter adjustment instruction area D5 displays a GUI for adjusting the scan parameters. The scan parameters include an interscan time and the number of repetitions of OCT B-scans for the same cross section. Here, the interscan time corresponds to the scan timing interval between B-scans repeatedly performed for OCT.

[0232] For example, the scan parameter adjustment instruction area D5 displays an interscan time adjustment object D51 and a repetition count adjustment object D52. When the user uses the operation unit 240B to specify the interscan time adjustment object D51 and change the interscan time, the interscan time among the scan parameters is updated. Similarly, when the user uses the operation unit 240B to specify the repetition count adjustment object D52 and change the number of B-scan repetitions, the number of B-scan repetitions among the scan parameters is updated.

[0233] In this embodiment, VISTA processing is performed based on a tomographic image of the fundus oculi Ef of the subject's eye E, so that VISTA analysis results can be acquired in real time. As a result, it becomes easier to adjust the scan parameters required for more detailed analysis results, and new analysis results can be acquired almost in real time by reflecting the changes in the scan parameters as described above.

[0234] For example, the user operates the operation unit 240B to specify a pixel position in the image displayed in the tomographic image display area D2 (pixel position P1 in FIG. 18 ) or a pixel position in the live image displayed in the live image display area D3. The main controller 211 controls the analysis unit 232 of the data processing unit 230 to identify the time change of the flow parameter at pixel position P1 as shown in FIG. 18 , and causes the display unit 240A to display an image representing the time change of the flow parameter. As described above, the user repeatedly adjusts the scan parameters using the operation unit 240B, performs OCT measurement using the adjusted scan parameters, and performs VISTA processing. This makes it possible to easily obtain analysis results in which the time change of the flow parameter is clearly indicated.

[0235] 19 is a schematic diagram showing another example of the display on the display unit 240A in step S33. In FIG. 19, the same parts as in FIG. 18 are denoted by the same reference numerals, and the description thereof will be omitted where appropriate.

[0236] The analysis result display area D1 shown in Fig. 19 differs from the analysis result display area D1 shown in Fig. 18 in that a VISTA image group display area D6 is provided instead of the scan parameter adjustment instruction area D5. Note that one of the multiple B-scan images used to generate the VISTA image is displayed in the tomographic image display area D2 in Fig. 19.

[0237] In the VISTA image group display area D6, a VISTA image group including a plurality of VISTA images (e.g., VISTA images VMA1 to VMA4) formed sequentially from OCTA image groups acquired at mutually different timings is simultaneously displayed in chronological order. In some embodiments, by sequentially displaying a plurality of VISTA images at regular time intervals in the same location in the VISTA image group display area D6, a moving image (e.g., slow motion) of the time change in the time fluctuation of the motion contrast intensity is displayed.

[0238] 18 illustrates a case where the scan parameters are adjusted by a user operation, but the configuration according to the embodiment is not limited to this. For example, the scan parameters may be automatically adjusted based on the analysis results of VISTA.

[0239] At this time, the data processing unit 230 performs processing to adjust scan parameters of the OCT scan (B-scan) to obtain better analysis results of VISTA, based on the analysis results of VISTA obtained by the analysis unit 232. That is, the data processing unit 230 adjusts scan parameters of the OCT B-scan, which is performed by the main controller 211 controlling the OCT unit 100, etc., based on the temporal variation of the motion contrast intensity at each of one or more positions on the cross section of the OCTA image. In some embodiments, the scan parameter adjustment function in the data processing unit 230 is performed by the controller 210 (main controller 211).

[0240] (First Example of Adjustment of Scan Parameters) In this embodiment, the longer the interscan time, the more vascular regions reach the saturation state of the above-mentioned non-correlation value corresponding to the time variation of the motion contrast intensity. On the other hand, the shorter the interscan time, the more vascular regions there are in a state before the transition to the saturation state of the non-correlation value (see FIG. 8 ). Therefore, the data processing unit 230, as a scan parameter adjustment unit, adjusts the interscan time based on the hue value of the specified vascular region so that the hue value falls between the saturation state of the non-correlation value and the lower limit of detection of the non-correlation value.

[0241] 16 in accordance with the scan parameters including the interscan time adjusted by the data processing unit 230, and executes VISTA processing based on the acquired measurement data. Then, the main control unit 211 repeats the adjustment of the interscan time, the OCT re-measurement, and VISTA until the hue value of the specified vascular region in the obtained VISTA image reaches the desired hue value.

[0242] (Second Example of Adjustment of Scan Parameter) In the embodiment, the shorter the interscan time, the smaller the amount of change in the flow parameter identified by the flow parameter analysis unit 232B over time (see FIG. 18 or 19 ). Therefore, the data processing unit 230, as a scan parameter adjustment unit, adjusts the interscan time so that the amount of change in the flow parameter over time is equal to or greater than a predetermined threshold.

[0243] 16 in accordance with the scan parameters including the interscan time adjusted by the data processing unit 230, and then executes VISTA processing based on the acquired measurement data, and then executes time analysis of the flow parameters.The main control unit 211 repeats the adjustment of the interscan time, re-measurement of the OCT, VISTA, and time analysis of the flow parameters until the amount of change in the obtained time change of the flow parameters reaches or exceeds a predetermined threshold.

[0244] (Third Example of Adjustment of Scan Parameter) In this embodiment, the amount of change in the flow parameter over time increases in synchronization with the timing of the subject's pulsation (see FIG. 18 or 19 ). Therefore, the data processing unit 230, as a scan parameter adjustment unit, adjusts the inter-scan time so that the pulsation period falls within the range.

[0245] 16 in accordance with the scan parameters including the interscan time adjusted by the data processing unit 230, and then executes VISTA processing based on the acquired measurement data, and then executes time analysis of the flow parameters. Then, the adjustment of the interscan time, OCT re-measurement, VISTA, and time analysis of the flow parameters are repeated until the time change of the flow parameters fits within the period of the subject's heartbeat.

[0246] (Fourth Example of Adjustment of Scan Parameters) The hue value assigned to each pixel of the VISTA image generated by the VISTA processing unit 232A depends on the interscan time. Therefore, the data processing unit 230, as a scan parameter adjustment unit, adjusts the interscan time so that the range of hue values ​​in the entire VISTA image or in a specified region becomes a desired range.

[0247] 16 in accordance with the scan parameters including the interscan time adjusted by the data processing unit 230, and executes VISTA processing based on the acquired measurement data. Then, the main control unit 211 repeats the adjustment of the interscan time, OCT re-measurement, and VISTA until the range of hue values ​​in the entire acquired VISTA image or in a predetermined region thereof falls within a desired range.

[0248] (Fifth Adjustment Example of Scan Parameters) The inter-scan time and the number of B-scan repetitions may be adjusted by specifically analyzing changes in the decorrelation value (or temporal fluctuations in motion contrast intensity) at a specified pixel or specified region in a VISTA image. In this adjustment example, the number of B-scan repetitions is adjusted so that VISTA analysis results are obtained at a predetermined specified pixel with an optimal inter-scan time at a specified number of B-scan repetitions, and then the number of B-scan repetitions is adjusted. Up to a specified number, the greater the number of B-scan repetitions, the more accurate the VISTA analysis results can be. On the other hand, as the number of B-scan repetitions increases, the longer the OCT measurement time, which depends on the OCT scan time specific to the ophthalmic apparatus 1, and the greater the burden on the subject. In this adjustment example, the number of B-scan repetitions is adjusted so that it is as small as possible, but not more than a predetermined maximum number of repetitions.

[0249] 20 and 21 show a flow diagram of the fifth example of adjusting scan parameters. A computer program for realizing the processes shown in Fig. 20 and Fig. 21 is stored in the storage unit 212. The main control unit 211 operates in accordance with this computer program to execute the processes shown in Fig. 20 and Fig. 21.

[0250] (S41: Initialize Scan Parameters) First, the main controller 211 initializes the inter-scan time and the number of repetitions of B-scan as scan parameters.

[0251] (S42: OCT Scan) Next, the main controller 211 controls the OCT unit 100 and the like to perform an OCT scan in accordance with the scan parameters set at the time of execution of step S42, thereby acquiring OCT data and an OCT image (B-scan image).

[0252] (S43: Next?) The main controller 211 determines whether or not to perform the next OCT scan, according to the number of repetitions in the scan parameters set at the time of execution of step S43.

[0253] When it is determined that the next OCT scan is to be performed (step S43: Y), the process of this adjustment example proceeds to step S42. When it is determined that the next OCT scan is not to be performed (step S43: N), the process of this adjustment example proceeds to step S44.

[0254] (S44: Generate OCTA image) When it is determined in step S43 that the next OCT scan will not be performed (step S43: N), the main controller 211 controls the OCTA image generator 231 to generate multiple OCTA images with different inter-scan time intervals from multiple OCT images obtained by repeatedly executing step S42.

[0255] (S45: Calculate the non-correlation value) Next, the main control unit 211 controls the VISTA processing unit 232A to calculate the non-correlation value at the designated pixel for each of the multiple OCTA images generated in step S44 (see FIG. 8).

[0256] (S46: First Condition Satisfied?) Next, the main control unit 211 determines whether the inter-scan time at the time of executing step S46 satisfies a predetermined first condition. The first condition is a condition that restricts the upper limit of the inter-scan time. In this adjustment example, the first condition is that "when the decorrelation values ​​are sorted in order of longest (shortest) inter-scan time, two or more consecutive decorrelation values, including the decorrelation value with the longest inter-scan time, are saturated." For example, by determining whether the difference between the decorrelation value and the saturation level D for each of the two or more decorrelation values ​​is within a predetermined threshold, it is possible to determine whether the two or more consecutive decorrelation values ​​are saturated.

[0257] If it is determined that the interscan time satisfies the first condition (S46: Y), the process of this adjustment example proceeds to step S47. If it is determined that the interscan time does not satisfy the first condition (S46: N), the process of this adjustment example proceeds to step S48.

[0258] (S47: Satisfies Second Condition?) When it is determined in step S46 that the interscan time satisfies the first condition (step S46: Y), the main control unit 211 determines whether the interscan time at the time of executing step S47 satisfies a predetermined second condition. The second condition is a condition that restricts the lower limit of the interscan time. In this adjustment example, the second condition is that "the decorrelation value with the shortest interscan time is not saturated." For example, by determining whether the decorrelation value with the shortest interscan time is smaller than the decorrelation value with the next shortest interscan time, it is possible to determine whether the decorrelation value with the shortest interscan time is not saturated.

[0259] If it is determined that the interscan time satisfies the second condition (S47: Y), the process of this adjustment example proceeds to step S49. If it is determined that the interscan time does not satisfy the second condition (S47: N), the process of this adjustment example proceeds to step S50.

[0260] (S48: Increase number of repetitions?) When it is determined in step S46 that the interscan time does not satisfy the first condition (S46: N), the main controller 211 determines whether to increase the number of repetitions of the B scan. For example, when the number of repetitions of the B scan at the time of execution of step S48 is equal to or less than a predetermined maximum number of repetitions, the main controller 211 determines to increase the number of repetitions. When the number of repetitions of the B scan is the predetermined maximum number of repetitions, the main controller 211 determines not to increase the number of repetitions.

[0261] When it is determined in step S48 that the number of repetitions of the B scan should be increased (S48: Y), the process of this adjustment example proceeds to step S53. When it is determined in step S48 that the number of repetitions of the B scan should not be increased (S48: N), the process of this adjustment example proceeds to step S54.

[0262] (S49: Is the number of repetitions minimum?) When it is determined in step S47 that the interscan time satisfies the second condition (S47: Y), the main controller 211 determines whether the number of repetitions of the B scan is minimum at the time of executing step S49. For example, a minimum number of repetitions of the B scan is determined in advance to obtain analysis results with a predetermined accuracy or higher. When the number of repetitions of the B scan is the predetermined minimum number of repetitions at the time of executing step S49, the main controller 211 determines that the current number of repetitions is minimum. When the number of repetitions of the B scan is greater than the predetermined minimum number of repetitions, the main controller 211 determines that the number of repetitions is not minimum.

[0263] When it is determined that the number of repetitions of the B scan is the minimum at the time of execution of step S49 (S49: Y), the process of this adjustment example proceeds to step S51. When it is determined that the number of repetitions of the B scan is not the minimum at the time of execution of step S49 (S49: N), the process of this adjustment example proceeds to step S52.

[0264] (S50: Shorten the interscan time) When it is determined in step S47 that the interscan time does not satisfy the second condition (S47: N), the main control unit 211 shortens the interscan time by a predetermined time. Following step S50, the process of this adjustment example proceeds to step S42.

[0265] (S51: Save scan parameters) When it is determined in step S49 that the number of repetitions of the B-scan is the minimum (S49: Y), the main controller 211 sets the inter-scan time and the number of repetitions of the B-scan at the time of execution of step S51 as new scan parameters and sets them as scan conditions. The updated scan conditions are saved in the memory unit 212.

[0266] After step S51, the process of this adjustment example ends (END).

[0267] (S52: Decrease the number of repetitions) When it is determined in step S49 that the number of repetitions of the B-scan is not the minimum (S49: N), the main controller 211 decreases the number of repetitions by 1. Following step S52, the processing of this adjustment example proceeds to step S42.

[0268] (S53: Increase the number of repetitions) When it is determined in step S48 that the number of repetitions of the B scan should be increased (S48: Y), the main controller 211 increases the number of repetitions of the B scan by 1. Following step S53, the processing of this adjustment example proceeds to step S42.

[0269] (S54: Increase interscan time) When it is determined in step S48 that the number of repetitions of B-scan should not be increased (S48: N), the main control unit 211 increases the interscan time by a predetermined time. Following step S54, the process of this adjustment example proceeds to step S42.

[0270] In the fifth adjustment example, an example was described in which scan parameters were adjusted using the decorrelation value of a designated pixel in a VISTA image, but this is not limiting. For example, for each of multiple pixels in a designated region in a VISTA image, optimal scan parameters for each pixel may be identified as shown in FIGS. 20 and 21 , and statistical values ​​such as the mode and median of the identified multiple scan parameters may be adjusted as new scan parameters. That is, scan parameters for a B-scan may be adjusted based on the time variation of motion contrast intensity at each of one or more positions in a cross section of the fundus oculi Ef. The designated region may be the entire VISTA image or a region of interest in the VISTA image. The multiple pixels in the designated region may be all pixels in the designated region.

[0271] As described above, according to the embodiment, since VISTA processing is performed based on B-scan images, it is possible to generate VISTA analysis results in real time. As a result, it is no longer necessary to acquire volume data, it is possible to easily adjust scan parameters, and it is possible to easily obtain effective VISTA analysis results.

[0272] The data processing unit 230 (or the data processing unit 230 and the control unit 210) is an example of an "adjustment unit" according to the embodiment.

[0273] [Operation] The analysis processing device, optical coherence tomography device, analysis processing method, and program according to the embodiment will be described.

[0274] A first aspect of the embodiment is an analysis processing device (1100, analysis processing unit 1100a, arithmetic and control unit 200 (control unit 210, image forming unit 220, and data processing unit 230)) including an acquisition unit (1110), an analysis unit (1120, 232), and a display control unit (1130, 211A). The acquisition unit acquires two or more pieces of motion contrast data (OCTA images) of cross sections at different inter-scan time intervals obtained by repeatedly performing B-scans three or more times on the same cross section of the object to be measured (fundus oculi Ef). The analysis unit executes an analysis process (VISTA) that determines the time variation of motion contrast intensity in the cross section based on the two or more pieces of motion contrast data. The display control unit displays an image (VISTA image) representing the time variation of motion contrast obtained by the analysis process on a display means (display device 3, display unit 240A).

[0275] According to this aspect, an analysis process is performed to determine the time variation of motion contrast intensity in a cross section of a measured object based on B-scan images, which significantly reduces the measurement time and the time required for analysis, and also significantly reduces the amount of data required for analysis. As a result, it becomes possible to generate the results of the analysis process in real time. Furthermore, because it becomes possible to generate the results of the analysis process in real time, it becomes possible to easily optimize scan parameters, including the inter-scan time and the number of B-scan repetitions, and it becomes possible to improve the accuracy of the analysis results.

[0276] In a second aspect of the embodiment, in the first aspect, the acquisition unit acquires two or more contrast data groups (OCTA image groups) acquired at different times and each including two or more motion contrast data. The analysis unit sequentially performs an analysis process on each of the two or more contrast data groups. The display control unit simultaneously displays two or more images representing time variations obtained by the analysis process on a screen of a display means, or sequentially displays the two or more images representing the time variations at the same position on the display means.

[0277] According to this aspect, it becomes easy to visually grasp the time-dependent change in the motion contrast intensity.

[0278] In a third aspect of the embodiment, in the first or second aspect, the analysis unit generates an image representing the time variation in real time.

[0279] According to this aspect, it becomes possible to grasp in real time the position where the motion contrast intensity fluctuates over time.

[0280] In a fourth aspect of the embodiment, in the first or second aspect, the analysis unit generates an image representing time variation based on a saturation time of the motion contrast intensity at each of a plurality of positions on the cross section.

[0281] According to this aspect, it becomes possible to easily grasp, for each part of the object to be measured, the parts where the rate of change of the motion contrast is relatively fast and the parts where the rate of change is slow.

[0282] In a fifth aspect of the embodiment, the analysis unit generates information representing the time change of the time fluctuation (time change of the flow parameter) at a specified position on the cross section.

[0283] According to this aspect, the relative speed of change of the motion contrast at the specified position can be easily grasped.

[0284] In a sixth aspect of the embodiment, in the fifth aspect, the display control unit causes the display means to display information representing a time change of the time fluctuation.

[0285] According to this aspect, it is possible to easily grasp the change over time in the relative change rate of the motion contrast at the specified position.

[0286] A seventh aspect of the embodiment is the first or second aspect, further including an adjustment unit (data processing unit 230, data processing unit 230 and control unit 210) that adjusts scan parameters of the B-scan based on the time variation of the motion contrast intensity at each of one or more positions in the cross section.

[0287] According to this aspect, it is possible to easily adjust scan parameters that can accurately identify the time variation of the motion contrast intensity in the object to be measured.

[0288] In an eighth aspect of the embodiment, in the seventh aspect, the scan parameters include an inter-scan time and the number of repetitions of B-scans for the same cross section.

[0289] According to this aspect, by adjusting the interscan time and the number of repetitions of B-scans, it becomes easy to properly identify the time variation of the motion contrast intensity in the object to be measured.

[0290] A ninth aspect of the embodiment is an optical coherence tomography device (1400) including an optical system (OCT optical system 1210, an optical system from the objective lens 22 to the OCT unit 100 shown in FIG. 10 ) and the analysis processing device of the first or second aspect. The optical system performs optical coherence tomography on the object to be measured. The analysis processing device displays an image representing time fluctuations in motion contrast intensity on a display means (display device 3, display unit 240A) based on two or more pieces of motion contrast data obtained by repeatedly performing B-scans on the same cross section of the object to be measured three or more times using the optical system.

[0291] According to this aspect, an analysis process is performed to determine the time variation of motion contrast intensity in a cross section of a measured object based on B-scan images, which significantly reduces the measurement time and the time required for analysis, and also significantly reduces the amount of data required for analysis. As a result, it becomes possible to generate the results of the analysis process in real time. Furthermore, because it becomes possible to generate the results of the analysis process in real time, it becomes possible to easily optimize scan parameters, including the inter-scan time and the number of B-scan repetitions, and it becomes possible to improve the accuracy of the analysis results.

[0292] A tenth aspect of the embodiment is an analysis processing method including an acquisition step, an analysis step, and a display control step. The acquisition step acquires two or more pieces of motion contrast data (OCTA images) of cross sections at different inter-scan time intervals obtained by repeatedly performing B-scans three or more times on the same cross section of the object to be measured (fundus oculi Ef). The analysis step executes an analysis process that determines temporal fluctuations in motion contrast intensity in the cross section based on the two or more pieces of motion contrast data. The display control step displays an image representing the temporal fluctuations obtained by the analysis process on a display means (display device 3, display unit 240A).

[0293] According to this aspect, an analysis process is performed to determine the time variation of motion contrast intensity in a cross section of a measured object based on B-scan images, which significantly reduces the measurement time and the time required for analysis, and also significantly reduces the amount of data required for analysis. As a result, it becomes possible to generate the results of the analysis process in real time. Furthermore, because it becomes possible to generate the results of the analysis process in real time, it becomes possible to easily optimize scan parameters, including the inter-scan time and the number of B-scan repetitions, and it becomes possible to improve the accuracy of the analysis results.

[0294] In an eleventh aspect of the embodiment, in the tenth aspect, the acquiring step acquires two or more contrast data groups acquired at different times and each including two or more motion contrast data, the analyzing step sequentially performs an analysis process on each of the two or more contrast data groups, and the display control step simultaneously displays two or more images representing time variations obtained by the analysis process on a screen of a display means, or sequentially displays the two or more images representing the time variations at the same position on the display means.

[0295] According to this aspect, it becomes easy to visually grasp the time-dependent change in the motion contrast intensity.

[0296] In a twelfth aspect of the embodiment, in the tenth or eleventh aspect, the analyzing step generates an image showing time variation in real time.

[0297] According to this aspect, it becomes possible to grasp in real time the position where the motion contrast intensity fluctuates over time.

[0298] In a thirteenth aspect of the embodiment, in the tenth or eleventh aspect, the analyzing step generates an image representing time variation based on a saturation time of the motion contrast intensity at each of a plurality of positions in the cross section.

[0299] According to this aspect, it becomes possible to easily grasp, for each part of the object to be measured, the parts where the rate of change of the motion contrast is relatively fast and the parts where the rate of change is slow.

[0300] In a fourteenth aspect of the embodiment, in the tenth or eleventh aspect, the analyzing step generates information representing a time change of a time fluctuation at a specified position on the cross section.

[0301] According to this aspect, the relative speed of change of the motion contrast at the specified position can be easily grasped.

[0302] In a fifteenth aspect of the embodiment, in the fourteenth aspect, the display control step causes the display means to display information representing a time change of the time fluctuation.

[0303] According to this aspect, it is possible to easily grasp the time change in the relative change rate of the motion contrast at the specified position.

[0304] A sixteenth aspect of the embodiment is the tenth or eleventh aspect, further comprising an adjusting step of adjusting scan parameters of the B-scan based on the time variation of the motion contrast intensity at each of one or more positions in the cross section.

[0305] According to this aspect, it is possible to easily adjust scan parameters that can accurately identify the time variation of the motion contrast intensity in the object to be measured.

[0306] In a seventeenth aspect of the embodiment, in the sixteenth aspect, the scan parameters include an inter-scan time and a number of repetitions of B-scans for the same cross section.

[0307] According to this aspect, by adjusting the interscan time and the number of repetitions of B-scans, it becomes easy to properly identify the time variation of the motion contrast intensity in the object to be measured.

[0308] An eighteenth aspect of the embodiment is a program for causing a computer to execute each step of the analysis processing method of the tenth or eleventh aspect.

[0309] According to this aspect, an analysis process is performed to determine the time variation of motion contrast intensity in a cross section of a measured object based on B-scan images, which significantly reduces the measurement time and the time required for analysis, and also significantly reduces the amount of data required for analysis. As a result, it becomes possible to generate the results of the analysis process in real time. Furthermore, because it becomes possible to generate the results of the analysis process in real time, it becomes possible to easily optimize scan parameters, including the inter-scan time and the number of B-scan repetitions, and it becomes possible to improve the accuracy of the analysis results.

[0310] The embodiment described above is merely an example of the present invention. Those who intend to implement the present invention may freely make modifications (omissions, substitutions, additions, etc.) within the scope of the gist of the present invention.

[0311] In some embodiments, a program that causes a computer to execute the analysis processing method is stored in the storage unit 212. Such a program may be stored in any non-transitory computer-readable recording medium. The recording medium may be an electronic medium that uses magnetic, optical, magneto-optical, semiconductor, or the like. Typically, the recording medium is a magnetic tape, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, a solid-state drive, or the like.

[0312] 1 Ophthalmic apparatus 210 Control unit 230 Data processing unit 231 OCTA image generation unit 232, 1120 Analysis unit 232A, 1121 VISTA processing unit 232B Flow parameter analysis unit 1000, 1000a Analysis system 1100 Analysis processing device 1100a Analysis processing unit 1110 Acquisition unit 1122 Flow parameter analysis unit 1200, 1400 OCT apparatus 1210 OCT optical system 1300 Display device IM1 to IM7 B-scan image (OCT image) IMA11 to IMA14, IMA21 to IMA24 OCTA image VMA1, VMA2 VISTA image

Claims

1. An analysis processing device including: an acquisition unit that acquires two or more pieces of motion contrast data of the same cross section of a measured object at mutually different interscan time intervals, the motion contrast data being obtained by repeatedly performing B-scans three or more times on the same cross section; an analysis unit that executes an analysis process that determines the time variation of motion contrast intensity in the cross section based on the two or more pieces of motion contrast data; and a display control unit that displays an image representing the time variation obtained by the analysis process on a display means.

2. The analysis processing device described in claim 1, characterized in that the acquisition unit acquires two or more groups of contrast data that are acquired at different times and each include the two or more motion contrast data, the analysis unit sequentially executes the analysis process on each of the two or more groups of contrast data, and the display control unit simultaneously displays two or more images representing the time variations obtained by the analysis process on the screen of the display means, or sequentially displays the two or more images representing the time variations in the same position on the display means.

3. The analytical processing device according to claim 1 or 2, characterized in that the analysis unit generates an image representing the time variation in real time.

4. The analysis processing device according to claim 1 or 2, characterized in that the analysis unit generates an image representing the time variation based on the saturation time of the motion contrast intensity at each of multiple positions on the cross section.

5. The analytical processing device according to claim 1 or 2, characterized in that the analysis unit generates information representing the time change of the time fluctuation at a specified position on the cross section.

6. The analysis processing device according to claim 5, characterized in that the display control unit causes the display means to display information representing the time change of the time fluctuation.

7. The analysis processing device according to claim 1 or 2, further comprising an adjustment unit that adjusts scan parameters of the B-scan based on the time variation of the motion contrast intensity at each of one or more positions on the cross section.

8. The analysis processing device according to claim 7, wherein the scan parameters include an interscan time and a number of repetitions of the B-scan for the same cross section.

9. An optical coherence tomography device comprising: an optical system that performs optical coherence tomography on the object to be measured; and an analysis processing device as described in claim 1 or claim 2, which displays an image representing the time variation on the display means based on the two or more motion contrast data obtained by repeatedly performing B-scans three or more times on the same cross section of the object to be measured using the optical system.

10. An analysis processing method comprising: an acquisition step of acquiring two or more motion contrast data of the same cross section of a measured object at mutually different interscan time intervals obtained by repeatedly performing B-scans three or more times on the same cross section; an analysis step of executing an analysis process of determining the time variation of motion contrast intensity in the cross section based on the two or more motion contrast data; and a display control step of displaying an image representing the time variation obtained by the analysis process on a display means.

11. The analysis processing method according to claim 10, characterized in that the acquisition step acquires two or more contrast data groups that are acquired at different times and each include the two or more motion contrast data, the analysis step sequentially executes the analysis process on each of the two or more contrast data groups, and the display control step simultaneously displays two or more images representing the time variations obtained by the analysis process on the screen of the display means, or sequentially displays the two or more images representing the time variations in the same position on the display means.

12. The analysis processing method according to claim 10 or 11, characterized in that said analysis step generates an image representing said time variation in real time.

13. The analysis processing method according to claim 10 or 11, characterized in that the analysis step generates an image representing the time variation based on a saturation time of the motion contrast intensity at each of a plurality of positions on the cross section.

14. The analysis processing method according to claim 10 or 11, characterized in that said analysis step generates information representing a time change of said time fluctuation at a specified position on said cross section.

15. The analysis processing method according to claim 14, characterized in that said display control step causes said display means to display information representing the time change of said time fluctuation.

16. The analysis processing method according to claim 10 or 11, further comprising an adjustment step of adjusting scan parameters of the B-scan based on the time variation of the motion contrast intensity at each of one or more positions in the cross section.

17. The analysis processing method according to claim 16, wherein the scan parameters include an interscan time and a number of repetitions of the B-scan for the same cross section.

18. A program for causing a computer to execute each step of the analysis processing method according to claim 10 or 11.

Images