JP2022164890A - Ophthalmologic imaging apparatus and ophthalmologic information processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To present blood flow information on a plurality of fundus blood vessels acquired by OCT blood flow measurement in an appropriate mode.

SOLUTION: An ophthalmologic imaging apparatus acquires a plurality of pieces of blood flow data by applying OCT blood flow measurement to a plurality of blood vessel positions of the fundus, acquires a front image of the fundus, displays a plurality of pieces of measurement position information indicating the blood vessel positions together with the front image, displays blood flow graphs based on the blood flow data in parallel with the front image, and displays in color a plurality of blood vessel images in the front image on the basis of the plurality of pieces of blood flow data or the plurality of blood flow graphs.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

The embodiments relate to an ophthalmologic photographing apparatus and an ophthalmologic information processing apparatus.

Image diagnosis occupies an important position in the field of ophthalmology. In recent years, the utilization of optical coherence tomography (OCT) is progressing. OCT has come to be used not only for acquiring B-scan images and three-dimensional images of the subject's eye, but also for acquiring front images (en-face images) such as C-scan images, projection images, and shadowgrams. there is

Furthermore, acquisition of an image in which a specific portion of the subject's eye is emphasized and acquisition of functional information are also performed. For example, it is possible to construct a B-scan image or a front image (vessel-enhanced image, angiogram) in which fundus blood vessels are emphasized based on time-series data acquired by OCT. This technique is called OCT angiography or the like. In addition, information on blood flow can be obtained based on phase information of time-series data collected by OCT. This technique is called OCT blood flow measurement or the like.

Japanese translation of PCT publication No. 2015-515894 JP 2013-184018 A

In some cases, it is desired to grasp the blood flow state of multiple blood vessels of the fundus for diagnosis or screening. In this case, OCT blood flow measurement is performed for each of a plurality of blood vessels in the fundus, and the obtained plurality of blood flow information is used as diagnostic material. However, the conventional technology cannot present such multiple pieces of blood flow information in a suitable manner.

An object of the embodiments is to provide a technique for presenting blood flow information of a plurality of fundus blood vessels acquired using OCT blood flow measurement in a suitable manner for diagnosis and screening.

An exemplary aspect of an embodiment applies optical coherence tomography (OCT) blood flow measurements to each of a plurality of vessel locations in a fundus of a subject eye to determine a plurality of blood flow corresponding to said plurality of vessel locations. a blood flow data acquisition unit for acquiring data; a front image acquisition unit for acquiring a front image of the fundus; and a display processing unit for displaying information on display means, wherein the display processing unit comprises the front image acquisition unit. display the front image acquired by, display a plurality of measurement position information indicating the plurality of blood vessel positions to which OCT blood flow measurement is applied, together with the front image, and at least one of the plurality of blood flow data at least one blood flow graph each representing a time-series change in a predetermined blood flow parameter is displayed in parallel with the front image, and the plurality of blood flow data or the plurality of blood flow data corresponding to these are displayed in parallel with the front image. The ophthalmologic imaging apparatus displays a plurality of blood vessel images in the front image corresponding to the plurality of blood vessel positions in color according to the blood flow amount based on the blood flow graph.

According to the embodiment, it is possible to present blood flow information of a plurality of fundus blood vessels acquired using OCT blood flow measurement in a suitable manner for diagnosis and screening.

1 is a schematic diagram illustrating an example configuration of an ophthalmic imaging apparatus according to an exemplary embodiment; FIG. FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; 4 is a flow chart representing an example of the operation of an ophthalmic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; 1 is a schematic diagram illustrating an example configuration of an ophthalmic imaging apparatus according to an exemplary embodiment; FIG. 1 is a schematic diagram illustrating an example configuration of an ophthalmic imaging apparatus according to an exemplary embodiment; FIG. 1 is a schematic diagram illustrating an example configuration of an ophthalmic imaging apparatus according to an exemplary embodiment; FIG. 1 is a schematic diagram showing an example of the configuration of an ophthalmologic information processing apparatus according to an exemplary embodiment; FIG.

Exemplary embodiments of the invention will be described with reference to the drawings. It is possible to incorporate any known technology, including the items described in the literature cited in this specification, into the embodiments.

An ophthalmologic imaging apparatus and an ophthalmologic information processing apparatus according to an embodiment have a function of displaying various types of information based on blood flow data obtained by applying OCT blood flow measurement to the fundus of an eye to be examined. For example, the ophthalmologic information processing apparatus according to the embodiment receives blood flow data obtained by applying OCT blood flow measurement to the fundus of the eye to be examined by a separately provided OCT device, and various information is obtained based on the blood flow data. display. On the other hand, the ophthalmologic imaging apparatus according to the embodiment acquires blood flow data by applying OCT blood flow measurement to the fundus of the subject's eye, and executes display of various information based on the blood flow data.

The data obtained by applying OCT to the fundus of the subject's eye (fundus OCT data) may be data in any form. For example, the fundus OCT data may include any one or more of the following (1) to (5).
(1) Data collected by OCT scanning of the fundus (raw data)
(2) Image data obtained by processing raw data (3) Intermediate data obtained during a series of processes for generating image data from raw data (4) Obtained by processing raw data Blood flow data (5) Intermediate data obtained during a series of processes for generating blood flow data from raw data

Note that the types of fundus OCT data are not limited to these. Embodiments can also process a variety of information associated with fundus OCT data. Examples of such information include subject identification information, subject eye identification information, identification information indicating whether the subject eye is the left eye or the right eye, photographing date and time, and the like.

An ophthalmologic imaging apparatus and an ophthalmologic information processing apparatus according to an embodiment include a processor that executes data display processing. The ophthalmologic information processing apparatus according to the embodiment may further include a processor that processes raw data and intermediate data. In addition to these processors, the ophthalmologic imaging apparatus according to the embodiment includes an optical system, drive system, control system, and data processing system for performing OCT.

The ophthalmologic imaging apparatus of the embodiment is configured to be able to perform Fourier domain OCT, for example. Fourier-domain OCT includes spectral-domain OCT and swept-source OCT. Spectral domain OCT is a method of constructing an image by acquiring a spectrum of interference light by spatial division using a broadband low-coherence light source and a spectroscope and performing a Fourier transform on it. Swept source OCT uses a wavelength swept light source (tunable light source) and a photodetector (balanced photodiode, etc.) to acquire the spectrum of interference light in a time-division manner, and constructs an image by Fourier transforming it. It is a method to The OCT method is not limited to Fourier domain OCT, and may be time domain OCT or amphasic OCT.

The ophthalmologic imaging apparatus and ophthalmologic information processing apparatus according to the embodiments may include modalities (for example, modalities other than OCT) for imaging the eye and/or other parts. Typical examples include fundus cameras, SLOs, slit lamp microscopes, ophthalmic surgical microscopes, and the like. Further, the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment may include a configuration for measuring characteristics of the eye and/or other parts and a configuration for performing an examination.

The ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment execute processing for displaying a front image of the fundus in addition to display processing based on the blood flow data of the fundus obtained by OCT blood flow measurement. The fundus front image is a fundus image from a viewpoint on the front side (cornea side) of the subject's eye. The front fundus image may be an image acquired by any modality. For example, the fundus front image may be an image constructed from data obtained by applying OCT to the fundus, or may be an image based on data obtained by applying a modality other than OCT to the fundus. A typical example of the latter is a fundus photograph (eg, color fundus image, monochrome fundus image, fluorescence image, etc.) obtained by a fundus camera or SLO. An ophthalmologic imaging apparatus according to an embodiment includes at least one of a configuration for OCT and a configuration for other modalities.

Data processing functions (arithmetic functions, image processing functions, control functions, etc.) in the ophthalmic photographing apparatus and ophthalmic information processing apparatus according to the embodiments include, for example, hardware such as processors and storage devices, arithmetic programs, image processing programs, and control functions. It is realized by cooperating with software such as a program. Part of the hardware may be provided in an external device capable of communicating with the ophthalmologic information processing apparatus or ophthalmologic imaging apparatus according to the embodiment. Also, at least part of the software may be pre-stored in the ophthalmologic information processing apparatus or ophthalmic imaging apparatus according to the embodiment, and/or may be pre-stored in an external device.

〈Ophthalmic imaging device〉
<Constitution>
An ophthalmic imaging apparatus according to an exemplary embodiment is described. FIG. 1 shows a configuration example of an ophthalmologic imaging apparatus according to this embodiment. The ophthalmologic imaging apparatus 1 collects fundus data using OCT, generates fundus blood flow data based on the collected data, acquires a front image of the fundus, and combines the fundus blood flow data and the fundus front image. Various information can be displayed based on

The fundus blood flow data is data representing the blood flow state (blood dynamics) in the fundus blood vessels (retinal blood vessels, choroidal blood vessels, etc.). Examples of fundus blood flow data include direction of blood flow, blood flow velocity, time-series change in blood flow velocity, blood flow, blood flow per unit time, time-series change in blood flow per unit time, and total blood flow. .

Further, the ophthalmologic imaging apparatus 1 can form an image representing the morphology of the fundus based on data collected using OCT. The fundus morphology image is an image representing the morphology of the fundus. Examples of fundus morphological images include B-scan images, C-scan images, projection images, shadowgrams, and blood vessel-enhanced images.

In this embodiment, both morphological images and blood flow data can be formed based on data obtained by applying OCT blood flow measurement to the fundus. Note that an OCT scan (for example, a B scan, a three-dimensional scan) for acquiring a morphological image and an OCT scan (OCT blood flow measurement) for acquiring blood flow data may be performed separately. . Also, an OCT scan may be performed to acquire data other than these. For example, OCT angiography can be performed.

Further, the ophthalmologic imaging apparatus 1 acquires the fundus front image described above. In this embodiment, the fundus frontal image may include an OCT frontal image such as a C-scan image, a projection image, or a shadowgram. The fundus frontal image may also include images acquired by any modality such as a fundus camera, SLO, slit lamp microscope, ophthalmic surgical microscope, and the like.

Part of the data used to display information may be acquired by another device. For example, one of the fundus blood flow data and the front fundus image may be acquired by another device. Alternatively, a fundus morphological image may be obtained by applying OCT to the fundus using another device. Data acquired by another device is input to the ophthalmologic imaging device according to the embodiment.

The ophthalmologic imaging apparatus 1 can display various types of information such as a fundus front image, blood flow information, and a fundus morphological image on the display device 2 . The display device 2 may be a part of the ophthalmologic imaging apparatus 1 or may be an external device connected to the ophthalmologic imaging apparatus 1 . Further, the ophthalmologic photographing apparatus 1 can send various information to a computer, a storage device, an ophthalmologic apparatus, and the like.

The ophthalmologic imaging apparatus 1 includes a control unit 10 , a storage unit 20 , an OCT data acquisition unit 30 , an operation unit 50 and a front image acquisition unit 60 . Control unit 10 includes scan control unit 11 , synchronization processing unit 12 , and display control unit 13 . The OCT data acquisition unit 30 includes an OCT scanner 31 , an image formation unit 32 and a blood flow data generation unit 33 .

Optionally, ophthalmic imaging device 1 may include data input 40 . Although the details will be described later, in the present embodiment, the data input unit 40 is provided when a configuration using biological information from a biological information monitor is applied.

<Control unit 10>
The control unit 10 controls each unit of the ophthalmologic imaging apparatus 1 . Control unit 10 includes a processor. 「プロセッサ」は、例えば、ＣＰＵ（Ｃｅｎｔｒａｌ Ｐｒｏｃｅｓｓｉｎｇ Ｕｎｉｔ）、ＧＰＵ（Ｇｒａｐｈｉｃｓ Ｐｒｏｃｅｓｓｉｎｇ Ｕｎｉｔ）、ＡＳＩＣ（Ａｐｐｌｉｃａｔｉｏｎ Ｓｐｅｃｉｆｉｃ Ｉｎｔｅｇｒａｔｅｄ Ｃｉｒｃｕｉｔ）、プログラマブル論理デバイス（例えば、ＳＰＬＤ（Ｓｉｍｐｌｅ Ｐｒｏｇｒａｍｍａｂｌｅ Ｌｏｇｉｃ Ｄｅｖｉｃｅ）、ＣＰＬＤ（Ｃｏｍｐｌｅｘ Ｐｒｏｇｒａｍｍａｂｌｅ Ｌｏｇｉｃ Ｄｅｖｉｃｅ） , FPGA (Field Programmable Gate Array)). The control unit 10 can realize the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or a memory device (the memory unit 20, an external device, etc.).

The control unit 10 may also include a communication interface for transmitting and receiving data via a communication line such as a local area network (LAN), the Internet, or a dedicated line.

<Scan control unit 11>
The scan controller 11 controls the OCT scanner 31 . For example, the scan control unit 11 controls the OCT scanner 31 to control the light source, control the optical scanner, change the optical path length of the measurement light and/or the reference light, adjust the polarization, adjust the amount of light, adjust the focus, and change the fixation position. Controls the various elements it contains. Some examples of processing that can be executed by the scan control unit 11 will be described later.

In this embodiment, OCT blood flow measurement is applied to each of a plurality of blood vessel positions in the fundus of the subject's eye. Thereby, a plurality of blood flow data corresponding to a plurality of blood vessel positions are obtained. The multiple blood vessel locations are multiple locations of one or more blood vessels in the fundus of the subject's eye. In this embodiment, each of the plurality of blood vessel positions corresponds to a section of interest, which will be described later.

<Synchronization processing unit 12>
The synchronization processing unit 12 executes processing for synchronizing at least one of a plurality of blood flow data corresponding to a plurality of blood vessel positions of the fundus and a plurality of blood flow graphs (described later) corresponding thereto.

That is, the synchronization processing unit 12 performs processing for synchronizing a plurality of blood flow data corresponding to a plurality of blood vessel positions of the fundus and processing for synchronizing a plurality of blood flow graphs based on these blood flow data. Either or both of

Thereby, it is possible to adjust the relative positional relationship (relative positional relationship in the time direction) between the plurality of blood flow graphs displayed on the display device 2 . In this embodiment, both the synchronization between a plurality of blood flow data and the synchronization between a plurality of blood flow graphs are executed for displaying a plurality of blood flow graphs. It can be said that the processing is substantially the same.

A blood flow graph is graph information representing time-series changes in a predetermined blood flow parameter created based on blood flow data corresponding to blood vessel positions in the fundus. The blood flow parameters represented by the blood flow graph may include at least one of arbitrary parameters indicated by the blood flow data and arbitrary parameters that can be obtained by processing the blood flow data. An example of blood flow graph will be described later.

In this embodiment, the blood flow parameters are, for example, the direction of blood flow, blood flow velocity, time-series change in blood flow velocity, blood flow, blood flow per unit time, time-series change in blood flow per unit time, and It may include any one or more parameters of total blood flow. However, the types of blood flow parameters are not limited to these.

The synchronization processing unit 12 may be configured, for example, to execute any one of the following first to third examples.

A first example of synchronization processing will be described. In this example, the synchronization processing unit 12 executes synchronization processing by referring to feature values of a plurality of blood flow data. More specifically, the synchronization processing unit 12 extracts feature values from each of a plurality of pieces of blood flow data, and synchronizes the plurality of pieces of blood flow data and/or performs a plurality of blood flow graphs based on the extracted feature values. synchronous processing. In this example, the feature value may be any feature value that can be identified by processing blood flow data, typically a peak value or the like. The synchronization processing unit 12 performs synchronization processing of a plurality of blood flow data and/or a plurality of blood flow graphs so that, for example, a plurality of feature values specified from a plurality of blood flow data are arranged at the same position on the time axis. synchronous processing can be performed.

A second example of synchronization processing will be described. In this example, the synchronization processing unit 12 executes synchronization processing with reference to waveforms of a plurality of blood flow graphs. More specifically, the synchronization processing unit 12 extracts waveform feature points from each of the plurality of blood flow data, and performs synchronization processing of the plurality of blood flow data and/or the plurality of blood flow data based on the extracted feature points. Execute flow graph synchronization. In this example, the feature points of the waveform may be any feature points that can be identified by processing the blood flow graph, typically peak points, zero slope points, inflection points, and feature patterns. It may be a point included in the portion to be displayed. The synchronization processing unit 12 performs synchronization processing of a plurality of blood flow data and/or a plurality of blood flow graphs so that, for example, a plurality of feature points identified from a plurality of blood flow graphs are arranged at the same position on the time axis. synchronous processing can be performed.

A third example of synchronization processing will be described. In this example, the synchronization process is executed with reference to the subject's biological information (vital signs) input via the data input unit 40 . The biometric information is obtained using any biometric monitor. A biological information monitor, also called a vital sign monitor, a clinical monitor, or the like, is a device for monitoring a person's vital signs. Vital signs include, for example, circulatory function, respiratory function, metabolic function, and brain function.

Examples of biological information monitors for measuring circulatory function include an electrocardiograph, a heart rate monitor, a pulse monitor, a blood pressure monitor, and the like. A respirometer is an example of a vital information monitor for measuring respiratory function. An activity meter is an example of a biological information monitor for measuring metabolic function. Examples of biological monitors for measuring brain function include electroencephalographs, magnetoencephalographs, and functional magnetic resonance imaging (fMRI) devices.

The biological information monitors listed above are merely examples, and biological information monitors applicable to the embodiments are not limited to these. For example, a biological information monitor for detecting vital signs such as body temperature, urination, defecation, and state of consciousness can be applied to the embodiment.

When this example is applied, the data input unit 40 is provided in the ophthalmologic photographing apparatus 1 . The data input unit 40 includes, for example, an interface (eg, communication interface, terminal, etc.) that receives signals output from the biological information monitor. The data input unit 40 receives, for example, the subject's biological information that changes in time series from the biological information monitor before and/or during the application of the OCT blood flow measurement. The synchronization processing unit 12 synchronizes at least one of the plurality of blood flow data and the plurality of blood flow graphs with each other based on the biological information received by the data input unit 40 .

In this example, the synchronization processing section 12 may be configured to control the operation of the data acquiring section 30 based on the biological information input from the biological information monitor.

For example, the synchronization processor 12 can control the operation of the OCT scanner 31 based on biological information detected by a biological information monitor. As a specific example thereof, when the biological information monitor includes an electrocardiogram, the synchronization processing unit 12 causes the OCT scanner 31 to synchronize with the timing of a predetermined time phase (for example, R wave) of the electrocardiogram obtained by the electrocardiogram. You can start scanning. Thereby, OCT blood flow measurement can be started with a predetermined time phase of heartbeat as a trigger.

In addition, the synchronization processing unit 12 can terminate scanning by the OCT scanner 31 in synchronization with a predetermined time phase (for example, R wave) of an electrocardiogram obtained by an electrocardiograph. Thereby, the OCT blood flow measurement can be terminated with a predetermined time phase of the heartbeat as a trigger.

Furthermore, as a combination of these, the synchronization processing unit 12 causes the OCT scanner 31 to start scanning in accordance with the timing of a predetermined time phase (for example, R wave) of the electrocardiogram obtained by the electrocardiograph, and repeats the time phase. The number of scans can be counted, and scanning can be terminated when the count value reaches a predetermined number of times (for example, once, twice, or three times). Blood flow data can thereby be collected over a period of time corresponding to a predetermined number of repetitions of the heartbeat cycle.

In another example, the synchronization processing unit 12 can control the image forming unit 32 to form an image corresponding to a predetermined time phase (for example, R wave) of an electrocardiogram obtained by an electrocardiograph. In addition, the synchronization processing section 12 can control the image forming section 32 to form a plurality of images over a period corresponding to a predetermined number of repetitions of the heartbeat cycle. In addition, the synchronization processing unit 12 selects an image corresponding to a predetermined time phase of the electrocardiogram from among the plurality of images acquired by the image forming unit 32, or selects an image group of the electrocardiogram over a predetermined period. It is possible.

In still another example, the synchronization processing unit 12 causes the blood flow data generation unit 33 to generate blood flow data according to the timing of a predetermined time phase (for example, R wave) of an electrocardiogram obtained by an electrocardiograph. can be controlled. In addition, the synchronization processing unit 12 can control the blood flow data generation unit 33 so as to form blood flow data over a period corresponding to a predetermined repetition number of heartbeat cycles. Further, the synchronization processing unit 12 selects blood flow data corresponding to a predetermined time phase of the electrocardiogram from among the plurality of blood flow data acquired by the blood flow data generation unit 33, and selects blood flow data corresponding to a predetermined time phase of the electrocardiogram. It is possible to select blood flow data sets spanning .

By applying any of the processes according to this example to the OCT blood flow measurement for each of a plurality of blood vessel positions in the fundus of the subject's eye, a plurality of blood flow data corresponding to the plurality of blood vessel positions can be synchronized with each other. Furthermore, multiple blood flow graphs based on multiple blood flow data can be synchronized with each other.

Synchronization processing that can be executed by the synchronization processing unit 12 is not limited to the above examples. Also, similar processing can be executed even when a biological information monitor of a type other than an electrocardiograph is applied.

<Display control unit 13>
The display control unit 13 executes control for displaying information on the display device 2 . The display control unit 13 can execute display control based on information stored in the storage unit 20 .

The display control unit 13 can perform processing (generation, processing, synthesis, etc.) related to information displayed on the display device 2 . Such processing may be executed by cooperation between the display control unit 13 and other elements (other elements of the control unit 10, the data processing unit 40, etc.).

<Storage unit 20>
Various data are stored in the storage unit 20 . In this example, at least OCT data 21 is stored in the storage unit 20 . The storage unit 20 may also store front images such as fundus photographs. At least part of the OCT data may be stored in an external storage device and provided to the ophthalmologic imaging apparatus 1 upon request. The storage unit 20 includes, for example, storage devices such as a hard disk drive and a semiconductor memory.

<OCT data 21>
The OCT data 21 includes any one or more of the fundus OCT data (1) to (5) described above. Typically, the ophthalmologic imaging apparatus 1 generates a morphological image and blood flow data from raw data collected by OCT scanning of the fundus, and stores OCT data 21 including these in the storage unit 20 . In other words, in a typical example, the OCT data 21 includes the aforementioned fundus OCT data (2) and (4). Further, when OCT angiography is applied, the OCT data 21 includes data acquired by OCT angiography, blood vessel-enhanced images based on this acquired data, and the like.

<OCT data acquisition unit 30>
The OCT data acquisition unit 30 applies OCT to the fundus of the subject's eye to acquire data (for example, at least part of the OCT data 21 stored in the storage unit 20). As described above, the OCT data acquisition section 30 includes the OCT scanner 31 , the image forming section 32 and the blood flow data generating section 33 . Image forming unit 32 includes a processor that executes an image forming program. The blood flow data generator 33 includes a processor that executes a blood flow data generation program.

<OCT scanner 31>
The OCT scanner 31 performs an OCT scan of the fundus under the control of the scan controller 11 . Thereby, fundus data (raw data) is collected. The OCT scanner 31 includes a configuration for performing optical interferometry using, for example, spectral domain OCT or swept source OCT. Such an OCT scanner 31 includes an OCT optical system, a driving system, a data acquisition system (DAQ), a control system, etc., as in the conventional art.

The OCT optical system includes, for example, an interference optical system, an optical scanner, and a photodetector. The interference optical system divides the light output from the light source into measurement light and reference light, projects the measurement light onto the fundus, and superimposes the return light of the measurement light from the fundus on the reference light to generate interference light. do. The optical scanner includes a galvanometer scanner or the like, and deflects measurement light. Thereby, the projection position of the measurement light with respect to the fundus is moved. The photodetector detects (the spectrum of) the interference light generated by the interference optics.

The drive system moves or operates the elements included in the OCT optical system. A data collection system collects detection results obtained sequentially by the OCT optics. The control system controls the OCT optical system, drive system, data acquisition system, etc. under the control of the scan controller 11 (or other elements of the controller 10).

In OCT blood flow measurement, the OCT scanner 31 repeatedly scans a cross section that intersects the blood vessel at a preset measurement position to collect data. In other words, the OCT scanner 31 acquires data by repeatedly scanning a section of interest that intersects the blood vessel of interest. The scan mode at this time is, for example, line scan (B scan). This line scan is, for example, repeatedly executed at a predetermined frequency. Data collected by such repeated scanning is sent to the image forming section 32 .

In the OCT blood flow measurement, the OCT scanner 31 also scans to obtain the inclination angle of the target blood vessel in the target cross section. This scan is performed, for example, on two cross-sections that intersect the vessel of interest. Here, two cross-sections can be placed near the cross-section of interest.

Note that one of the two cross sections for obtaining the inclination angle of the target blood vessel may be the target cross section itself. The other cross section is set near the cross section of interest. In this case, data obtained by repeated scanning of the cross section of interest can be used to calculate the tilt angle.

In summary, typically, the scans performed in OCT blood flow measurement may be a combination of repeated scans of the cross section of interest and scans of two other cross sections, or repeated scans of the cross section of interest and one other cross section. may be combined with the scan of

The mode of scanning for obtaining the inclination angle of the target blood vessel in the target cross section is not limited to these. For example, three or more cross-sections can be scanned. Alternatively, a three-dimensional area containing the section of interest can be scanned (three-dimensional scan). As another example, a cross-section that intersects the cross-section of interest and along the vessel of interest can be scanned. The OCT blood flow measurement will be described in detail in the explanation of the blood flow data generator 33. FIG.

When performing OCT angiography, the OCT scanner 31 scans a three-dimensional area of the fundus. The scan mode at this time is, for example, raster scan (three-dimensional scan). This raster scan is performed, for example, by scanning each of the plurality of B cross-sections (B scan planes) a predetermined number of times (for example, four times each). In other words, this raster scanning is performed so as to sequentially scan a plurality of B slices a predetermined number of times or to scan according to a predetermined sequence. A three-dimensional data set collected by the OCT scanner 31 is sent to the image forming section 32 .

The manner of scanning that can be performed by the OCT scanner 31 is not limited to the manner described above. For example, the OCT scanner 31 can perform line scans, circle scans, radial scans, three-dimensional scans, etc. as OCT scans for obtaining morphological images.

<Image forming unit 32>
The image forming unit 32 forms an OCT image based on data collected by the OCT scanner 31 . For example, in OCT blood flow measurement, the image forming unit 32 forms a plurality of cross-sectional images (B-scan images) for each B cross-section based on a three-dimensional data set acquired by the OCT scanner 31 . The image formation processing at this time includes, for example, noise removal (noise reduction), filtering, fast Fourier transform (FFT), etc., as in the conventional OCT technology.

The image forming unit 32 can construct stack data by embedding these cross-sectional images in a single three-dimensional coordinate system. In this stack data, a number of cross-sectional images corresponding to the number of scanning repetitions is assigned to each B cross-section. Furthermore, the image forming unit 32 can form volume data (voxel data) by performing interpolation processing or the like on this stack data. In this volume data, a number of voxel groups corresponding to the number of scanning repetitions are assigned to positions corresponding to each B section.

The image forming unit 32 renders stack data or volume data to produce B-scan images (longitudinal cross-sectional images, axial cross-sectional images), C-scan images (transverse cross-sectional images, horizontal cross-sectional images), projection images, shadowgrams, and so on. etc. can be formed.

An arbitrary cross-sectional image, such as a B-scan image or a C-scan image, is formed by selecting pixels (pixels, voxels) on a specified cross-section from a three-dimensional data set. Alternatively, an image of an arbitrary cross-section is formed by projecting a slice of preset thickness in its thickness direction.

A projection image is formed by projecting stack data or volume data in a predetermined direction (Z direction, depth direction, A scan direction). A shadowgram is formed by projecting a portion of stack data or volume data (for example, partial data corresponding to a specific layer) in a predetermined direction. A fundus image such as a C-scan image, a projection image, and a shadowgram whose viewpoint is the cornea side of the subject's eye is called a front image.

The image forming unit 32 can perform various image processing other than rendering. For example, there are segmentation for obtaining specific tissues and tissue boundaries, and size analysis for obtaining sizes of tissues (layer thickness, volume, etc.). If a particular layer (or a particular layer boundary) is determined by segmentation, it is possible to reconstruct the B-scan or frontal image so that the particular layer is flat. Such an image is called a flattened image.

The image forming unit 32 can form a blood vessel enhanced image. A blood vessel-enhanced image is an image obtained by specifying an image region (blood vessel region) corresponding to a blood vessel by analyzing OCT data and enhancing the blood vessel region by changing the expression mode of the blood vessel region. A plurality of OCT data obtained by repeatedly scanning substantially the same range of the subject's eye is used to identify the blood vessel region.

A blood vessel-enhanced image expresses, for example, the distribution of blood vessels in a three-dimensional region of the fundus that has been OCT-scanned (that is, the three-dimensional distribution of blood vessels). There are several types of techniques for forming a blood vessel-enhanced image. A typical method for that purpose will be described. For this processing, a three-dimensional data set including a plurality of B-scan images arranged in time series for each B-section is used by repeatedly scanning each of the plurality of B-sections of the subject's eye. As a technique for repeatedly scanning substantially the same B section, there are fixation and tracking.

In the process of forming a blood vessel-enhanced image, registration of a plurality of B-scan images is first performed for each B-section. This alignment is performed using, for example, a known image matching technique. As a typical example, it is possible to extract a characteristic region in each B-scan image and align a plurality of B-scan images by aligning the extracted characteristic regions.

A process is then performed to identify image regions that are changing between the registered B-scan images. This processing includes, for example, finding differences between different B-scan images. Each B-scan image is brightness image data representing the morphology of the subject's eye, and it is considered that the image area corresponding to the site other than blood vessels is substantially unchanged. On the other hand, considering that the backscatter that contributes to the interference signal varies randomly with blood flow, image regions where changes occur between multiple registered B-scan images (e.g. pixels with non-zero difference, or A pixel whose difference is equal to or greater than a predetermined threshold can be estimated to be a blood vessel region.

Information indicating that the image region is a blood vessel region is assigned to the image region specified in this way. Three-dimensionally distributed blood vessel regions are obtained by performing the above processing on a plurality of B cross-sections. By rendering such a three-dimensional blood vessel-enhanced image, a front image representing blood vessel distribution, an image of an arbitrary cross section, a shadowgram of an arbitrary range, and the like are generated.

Processing for forming a blood vessel-enhanced image is not limited to this. For example, it is possible to identify the blood vessel region by a conventional method using Doppler OCT, or to identify the blood vessel region by using a conventional image processing method. Also, by using different techniques depending on the site, it is possible to specify the blood vessel region for each site. For example, for the retina, the above-described typical technique or Doppler OCT technique can be used to identify the vascular area, and for the choroid, the image processing technique can be used to identify the vascular area.

<Blood flow data generator 33>
The blood flow data generator 33 operates in OCT blood flow measurement. The blood flow data generation unit 33, based on the image of the cross section of interest formed by the image forming unit 32 based on the data collected by the OCT scanner 31 in the OCT blood flow measurement, and the inclination angle of the blood vessel of interest in the cross section of interest, Blood flow data representing the state of blood flow in the vessel of interest is generated.

The data collected by the OCT scanner 31 in the OCT blood flow measurement are data (first data) collected by repeatedly scanning a cross section of interest intersecting the blood vessel of interest, and crossing the blood vessel of interest and different from the cross section of interest. and data (second data) obtained by scanning one or more cross-sections (cross-sections in the vicinity of the cross-section of interest). Note that instead of the second data, for example, the inclination angle of the target blood vessel at the position of the target cross section or its vicinity, which is acquired separately from the OCT blood flow measurement, can be used. As an example, it is possible to use the tilt angle obtained from the vessel-enhanced image obtained by OCT angiography.

The image forming unit 32 forms a morphological image and a phase image of the fundus based on the data collected by the OCT scanner 31 in the OCT blood flow measurement. A morphological image and a phase image obtained by OCT blood flow measurement are images corresponding to the same cross section. Typically, a morphological image and a phase image corresponding to the section of interest (section B) are obtained.

As mentioned above, in a typical OCT blood flow measurement, two types of scans (auxiliary scan and main scan) are performed on the fundus. Auxiliary scanning is performed to scan one or more cross-sections different from the cross-section of interest (cross-sections in the vicinity of the cross-section of interest) to acquire second data. In a typical auxiliary scan, two or more cross-sections intersecting the vessel of interest are scanned with the measurement light. The data acquired by the auxiliary scan are used to obtain the inclination angle of the vessel of interest in the section of interest. On the other hand, the main scan is performed to acquire the first data by repeatedly scanning the section of interest that intersects the blood vessel of interest with the measurement light. A cross-section on which the auxiliary scan is performed is placed near the cross-section of interest. This scan is Doppler measurement using OCT.

The target cross sections of the auxiliary scan and the main scan are oriented, for example, so as to be orthogonal to the running direction of the blood vessel of interest. In addition, the distance between the target cross section of the auxiliary scan and the cross section of interest (distance between cross sections) is set in advance or set for each examination. As an example of the latter, it is possible to set the distance between cross-sections based on predetermined factors such as the curvature of the target blood vessel in or near the target cross-section or the inspection accuracy. Alternatively, the user may set a desired cross-sectional distance.

This scan is preferably performed over at least one cardiac cycle of the patient's heart. This provides blood flow data for all phases of the heartbeat. The execution time of the main scan may be a preset constant time, or may be a time set for each patient or each examination.

For example, the image forming unit 32 generates a cross-sectional image representing the morphology of the first auxiliary cross section and a second A cross-sectional image representing the morphology of the target cross section is formed. At this time, it is possible to improve the image quality by using a technique such as averaging, or to select an optimum one from two or more cross-sectional images of each auxiliary cross-section.

Further, the image forming unit 32 forms a group of cross-sectional images representing time-series changes in the cross section of interest based on the data collected by the main scan (repetitive scan) of the cross section of interest. This processing is accomplished, for example, by forming cross-sectional images from the data collected for each scan iteration.

The processing executed by the image forming unit 32 includes, for example, noise removal (noise reduction), filtering, fast Fourier transform (FFT), etc., similar to conventional OCT technology. Note that the process of forming a cross-sectional image of the cross section of interest described here is the same as the morphological image forming process executed by the image forming unit 32 .

Furthermore, the image forming unit 32 forms a phase image representing the time-series change of the phase difference in the cross section of interest based on the data collected by the main scan of the cross section of interest. The data used for this processing is the same as the data used for forming the cross-sectional image(s) of the target cross-section. Therefore, there is a natural positional correspondence between the cross-sectional image of the cross section of interest and the phase image, and the registration is self-evident.

An example of a method of forming a phase image will be described. In a typical example, a phase image is obtained by calculating the phase difference between adjacent A-line complex signals (signals corresponding to adjacent scan points). In other words, the phase image of this example is formed based on time-series changes in the pixel values (luminance values) of each pixel of the cross-sectional image of the cross section of interest. For any pixel, the image forming unit 32 considers a graph of time-series changes in its luminance value. The image forming unit 32 obtains the phase difference Δφ between two times t1 and t2 (t2=t1+Δt) separated by a predetermined time interval Δt in this graph. Then, this phase difference Δφ is defined as the phase difference Δφ(t1) at time t1 (more generally, any time between two times t1 and t2). By executing this process for each of a large number of preset time points, a time-series change in the phase difference at the pixel is obtained.

A phase image is an image representing the phase difference value of each pixel at each point in time. This imaging processing can be realized, for example, by expressing the value of the phase difference by display color or brightness. At this time, the color (for example, red) indicating that the phase has increased along the time series can be made different from the color (for example, blue) that indicates that the phase has decreased. Also, the magnitude of the phase change amount can be expressed by the intensity of the display color. By adopting such an expression method, it becomes possible to express the direction and size of blood flow with colors and densities. A phase image is formed by executing the above processing for each pixel.

The time-series change of the phase difference can be obtained by sufficiently reducing the time interval Δt to secure the phase correlation. At this time, oversampling is performed by setting the time interval Δt to a value less than the time corresponding to the resolution of the cross-sectional image in the scanning of the measurement light.

The blood flow data generation unit 33 can execute, for example, a blood vessel region identification process, an inclination angle calculation process, and a blood flow data generation process. The blood flow data generation process includes, for example, at least a blood flow velocity calculation process, and may further include a blood vessel diameter calculation process and a blood flow volume calculation process.

In the blood vessel region identification process, the blood flow data generator 33 identifies the blood vessel region in each cross-sectional image corresponding to the target blood vessel. Furthermore, the blood flow data generator 33 identifies a blood vessel region in the phase image corresponding to the cross section of interest. Identification of the blood vessel region is performed by analyzing the pixel values of each image (for example, thresholding). The blood vessel region in the phase image may be identified based on the blood vessel region in the cross-sectional image corresponding to the cross section of interest and the result of registration between this cross-sectional image and the phase image.

In the inclination angle calculation process, the blood flow data generator 33 calculates the inclination angle of the target blood vessel in the target cross section based on the image (group) formed from the data acquired by the auxiliary scan.

An example of the tilt angle calculation process will be described. Please refer to FIG. Reference character B0 indicates a cross-sectional image (cross-sectional image of interest) in the cross-section of interest for which the blood vessel inclination angle is calculated. A blood vessel region V0 is depicted in the cross-sectional image of interest B0. Reference numerals B11 and B12 indicate two cross-sectional images (auxiliary cross-sectional images) in two auxiliary cross-sections located near the target cross-section B0. In the auxiliary cross-sectional image B11, a blood vessel region V11 in the auxiliary cross-section B11 of the same blood vessel (target blood vessel) as the blood vessel region V0 is depicted. Similarly, the auxiliary cross-sectional image B12 depicts a blood vessel region V12 in the auxiliary cross-section B12 of the target blood vessel.

The blood flow data generator 33 calculates the inclination of the target blood vessel in the target cross section based on the target cross-sectional image B0 and the auxiliary cross-sectional images B11 and B12. The number of auxiliary cross-sectional images to be referred to is not limited to two, and may be any number of one or more.

The blood flow data generator 33 calculates the inclination of the target blood vessel in the target cross section based on the blood vessel regions V0, V11, and V12 and the inter-section distance. The cross-sectional distance may be the distance between the auxiliary cross-sectional image B11 and the auxiliary cross-sectional image B12. Alternatively, the cross-sectional distance may be defined by at least one of the distance between the auxiliary cross-sectional image B11 and the cross-sectional image of interest B0 and the distance between the auxiliary cross-sectional image B12 and the cross-sectional image of interest B0. good. Let L be the distance between the auxiliary cross-sectional image B11 (or B12) and the target cross-sectional image B0.

The A-scan direction (the direction indicated by the arrow pointing downward) shown in FIG. 2 indicates, for example, the orientation of the A-scan image included in the target cross-sectional image B0. This A-scan image may be, for example, an A-scan image located in the center of a plurality of A-scan images included in the target cross-sectional image B0.

In a typical example, the blood flow data generator 33 can calculate the inclination A of the target blood vessel in the target cross section based on the positional relationship between the three blood vessel regions V0, V11 and V12. This positional relationship is obtained, for example, by connecting three blood vessel regions V0, V11 and V12. More specifically, the blood flow data generator 33 identifies feature points of the three blood vessel regions V0, V11 and V12, and connects these feature points. Feature points referred to here include the center position (axis position), the center of gravity position, the top, and the like. Methods of connecting these feature points include a method of connecting with a line segment, a method of connecting with an approximation curve (spline curve, Bezier curve, etc.).

Furthermore, the blood flow data generator 33 calculates the slope A based on the line connecting these feature points. When line segments are used, the blood flow data generating unit 33 generates, for example, a first line segment connecting the feature point of the blood vessel region V0 in the cross-sectional image of interest B0 and the feature point of the blood vessel region V11 in the auxiliary cross-sectional image B11. and the slope of the second line segment connecting the feature point of the blood vessel region V0 and the feature point of the blood vessel region V12 in the auxiliary cross-sectional image B12. As an example of this calculation process, the average value of the slopes of two line segments can be obtained. Also, as an example of connecting with an approximated curve, the slope of the approximated curve at the intersection position of the approximated curve and the cross section of interest can be obtained.

In this example, blood vessel regions in three cross sections are considered, but it is also possible to obtain the inclination by considering blood vessel regions in two cross sections. As a specific example, the inclination A of the target blood vessel in the target cross section can be obtained based on the blood vessel region V11 in the auxiliary cross-sectional image B11 and the blood vessel region V12 in the auxiliary cross-sectional image B12. Alternatively, the inclination A of the target blood vessel in the target cross section can be obtained based on the blood vessel region V11 in the auxiliary cross-sectional image B11 and the blood vessel region V0 in the target cross-sectional image B0. For example, the slope of the first line segment or the second line segment can be obtained and adopted as the slope A of the vessel of interest.

Also, in the above example, only one value of the slope A is obtained, but the slopes may be obtained for two or more positions (or regions) in the blood vessel region V0. In this case, two or more obtained slope values can be used separately, or one value (for example, average value) statistically obtained from these slope values can be used as the slope A.

In the blood flow data generation process, the blood flow data generation unit 33 generates data related to the blood vessel of interest based on the phase image formed based on the main scan (Doppler OCT) and the tilt angle obtained by the blood flow data generation unit 33. Generate blood flow data. As described above, in a typical example, the blood flow data generation process includes a blood flow velocity calculation process, a blood vessel diameter calculation process, and a blood flow volume calculation process.

The blood flow data generation unit 33 can calculate the blood flow velocity in the cross section of interest of the blood flowing through the blood vessel of interest based on the time series change of the phase difference obtained as the phase image. The value calculated by this process may be the blood flow velocity at a certain point in time, or may be the time series change in the blood flow velocity (blood flow velocity change data). In the former case, for example, it is possible to selectively acquire the blood flow velocity at a predetermined time phase of the electrocardiogram (for example, the time phase of the R wave). Also, the time range in the latter is the whole or an arbitrary part of the time when the section of interest is scanned.

When the blood flow velocity change data is obtained, the blood flow data generator 33 can calculate the statistic value of the blood flow velocity in the range of time. These statistics include mean, standard deviation, variance, median, maximum, minimum, maximum and minimum. It is also possible to create a histogram of blood velocity values.

The blood flow data generator 33 can calculate the blood flow velocity using the Doppler OCT method as described above. For example, the following relational expression is used to calculate the blood flow velocity.

Δf: Doppler shift received by scattered light of measurement light n: Refractive index of medium (blood) v: Flow velocity of medium (blood velocity)
θ: Angle (tilt angle) formed by the incident direction of the measurement light and the direction of the flow of the medium
λ: Center wavelength of measurement light

In a typical example, the refractive power n of the medium and the center wavelength λ of the measurement light are each known, the Doppler shift Δf is obtained from the time-series change of the phase difference, and the tilt angle θ is obtained from the tilt angle calculation process or the blood vessel angle distribution obtained from The blood flow data generator 33 can calculate the blood flow velocity v by substituting these values into the above relational expression.

In the blood vessel diameter calculation process, the blood flow data generator 33 calculates the diameter of the target blood vessel in the target cross section. Examples of this calculation method include a first calculation method using a front image of the fundus and a second calculation method using a cross-sectional image.

When the first calculation method is applied, the part of the fundus including the position of the cross section of interest is photographed in advance. This fundus photographing is performed by the front image acquiring unit 60, for example. Alternatively, a previously acquired and stored front image of the fundus may be read. A blood vessel-enhanced image may also be used.

The blood flow data generation unit 33 generates the image of the fundus based on various factors that determine the relationship between the scale on the image and the scale in the real space, such as the angle of view (magnification), the working distance, and information on the eyeball optical system. Sets the scale for the front image. This scale represents length in real space. As a specific example, this scale is obtained by associating the interval between adjacent pixels with the scale in real space (for example, the interval between pixels=10 μm). It is also possible to previously calculate the relationship between various values of the above factors and the scale in the real space, and to store information expressing this relationship in a table format or a graph format. In this case, scales corresponding to the above factors are selectively applied.

The blood flow data generation unit 33 calculates the diameter of the blood vessel of interest in the cross section of interest, that is, the diameter of the blood vessel region, based on this scale and the pixels included in the blood vessel region. As a specific example, the blood flow data generator 33 can obtain the maximum value and average value of diameters in various directions of the blood vessel region. Alternatively, the blood flow data generator 33 can approximate the contour of the blood vessel region to a circle or ellipse, and obtain the diameter of the circle or ellipse. Since the area of the blood vessel region can be (substantially) determined once the blood vessel diameter is determined, the area may be calculated instead of obtaining the blood vessel diameter.

A second calculation method will be described. In the second calculation method, a cross-sectional image of the fundus on the target cross-section is used. This cross-sectional image may be a cross-sectional image based on the main scan, or may be obtained separately. The scale of this cross-sectional image is determined according to the scanning mode of the measurement light. The length of the section of interest is determined based on various factors that determine the relationship between the scale on the image and the scale in the real space, such as working distance and eyeball optical system information. The blood flow data generator 33 can, for example, obtain the interval between adjacent pixels based on the length of the cross section of interest, and calculate the diameter of the blood vessel of interest in the cross section of interest in the same manner as in the first calculation method.

In the blood flow rate calculation process, the blood flow data generator 33 calculates the flow rate of blood flowing through the vessel of interest based on the blood flow velocity calculation result and the blood vessel diameter calculation result. An example of this processing is described below.

Assume that the blood flow in the blood vessel is Hagen-Poiseuille flow. Let w be the diameter of the blood vessel, and Vm be the maximum value of the blood flow velocity. In this case, the blood flow Q is represented by the following relational expression.

The blood flow data generation unit 33 substitutes the blood vessel diameter w obtained by the blood vessel diameter calculation process and the maximum value Vm in the blood flow velocity obtained by the blood flow velocity calculation process into the above relational expression, thereby obtaining (unit blood flow Q per hour) can be calculated.

<Operation unit 50>
The operation unit 50 is used by the user to input instructions to the ophthalmologic imaging apparatus 1 . The operation unit 50 may include known operation devices used in ophthalmologic apparatuses and computers. For example, the operation unit 50 may include a mouse, touch pad, trackball, keyboard, pen tablet, operation panel, joystick, button, switch, and the like.

The operation unit 50 may include a touch panel. In this case, the display control unit 13 can display a GUI for inputting instructions and information on the touch panel.

<Front image acquisition unit 60>
The front image acquisition unit 60 acquires a front image of the fundus. Processing for acquiring a front image is optional.

In the first example, the front image acquisition section 60 may include a configuration for photographing the fundus. For example, the front image acquisition unit 60 may include an optical system for any ophthalmologic modality, such as a fundus camera optical system, an SLO optical system, a slit lamp microscope optical system, or an ophthalmic surgical microscope optical system.

The front image may be an OCT front image such as a C-scan image, a projection image, a shadowgram, or a blood vessel-enhanced image. In this case, the front image acquisition section 60 may be included in the OCT data acquisition section 30 (in particular, the OCT scanner 31 and the image forming section 32).

Alternatively, the front image acquisition unit 60 forms a front image based on data acquired by the OCT data acquisition unit 30 (eg, data collected by the OCT scanner 31, image data formed by the image forming unit 32, etc.). may include a processor;

In the second example, the front image acquisition section 60 may include a configuration for acquiring a front image of the fundus of the subject's eye from an external device.

For example, the front image acquisition section 60 may include a communication interface for transmitting and receiving data via a communication line such as a LAN, Internet, dedicated line, or the like. In this case, the front image acquisition unit 60 can acquire the front image of the fundus of the subject's eye stored in, for example, an electronic medical record system or an image archiving system using a patient ID, DICOM tag, or the like as a search query.

Alternatively, the front image acquisition unit 60 may include a data reader that reads data (in particular, a front image of the fundus of the subject's eye) recorded in advance on a recording medium.

<motion>
An example of the operation of the ophthalmologic imaging apparatus 1 according to this embodiment will be described. A typical example of the operation of the ophthalmologic imaging apparatus 1 is shown in FIG. Preparatory processing such as input of patient ID, alignment of the optical system with respect to the eye to be examined, focus adjustment of the optical system, adjustment of the OCT optical path length, adjustment of the fixation position, setting of the OCT scan range, etc. has already been performed. and

(S1: Acquire a front image of the fundus)
First, the control unit 10 controls the front image acquiring unit 60 to acquire a front image of the fundus of the subject's eye. Note that the timing for acquiring the front image is not limited to this example.

Generally, any timing before OCT blood flow measurement, any timing while OCT blood flow measurement is being performed, any timing between OCT blood flow measurement and OCT blood flow measurement, and OCT blood flow A fundus image can be acquired at any arbitrary timing after measurement. For example, when an image obtained by visible light imaging is used as a front image, such as a color fundus image, the front image should be acquired after OCT blood flow measurement in consideration of the effect of miosis caused by visible light. can be controlled.

(S2: Apply OCT blood flow measurement to multiple blood vessel positions in the fundus)
The ophthalmologic imaging apparatus 1 applies OCT blood flow measurement to each of a plurality of blood vessel positions on the fundus of the subject's eye. In this example, the blood vessel position is set as the target cross section of the target blood vessel.

In OCT blood flow measurement, the scan controller 11 controls the light source and optical scanner included in the OCT scanner 31 . For each of a plurality of blood vessel positions (that is, a plurality of cross sections of interest), the OCT scanner 31 repeatedly scans a first cross section intersecting the blood vessel of interest at the blood vessel position under the control of the scan control unit 11 to obtain first data. and acquire second data by scanning one or more auxiliary cross-sections that intersect the blood vessel of interest in the vicinity of the cross-section of interest. The order of collecting the first data and collecting the second data is arbitrary.

(S3: Form a morphological image for each blood vessel position)
For each of a plurality of blood vessel positions (that is, a plurality of cross-sections of interest), the image forming unit 32 selects the first data corresponding to the cross-section of interest based on the first data collected by repeatedly scanning the cross-section of interest in step S2. The above morphological image (B scan image) is formed. Typically, the same number of morphological images can be formed as the number of scanning repetitions. As a result, for each of a plurality of blood vessel positions, time-series B-scan images corresponding to the blood vessel position are obtained. Note that the number of morphological images may be formed in a number smaller than the number of repetitions of scanning.

Furthermore, for each of the plurality of blood vessel positions, the image forming unit 32 generates a morphological image (B scan image).

Each morphological image formed in step S<b>3 is stored in the storage unit 20 as OCT data 21 .

(S4: For each blood vessel position, obtain the inclination angle of the target blood vessel)
For each of a plurality of blood vessel positions (that is, a plurality of cross sections of interest), the blood flow data generation unit 33, based on two or more morphological images among the plurality of morphological images formed in step S3 for the blood vessel position, The inclination angle of the target blood vessel in the target cross section is obtained. For this processing, for example, a combination of two morphological images corresponding to two auxiliary cross sections, or a combination of a morphological image corresponding to one auxiliary cross section and a morphological image corresponding to the cross section of interest is used.

(S5: Form a phase image for each blood vessel position)
For each of a plurality of blood vessel positions (that is, a plurality of cross sections of interest), the image forming unit 32 calculates the phase corresponding to the cross section of interest based on the first data collected by repeatedly scanning the cross section of interest in step S2. form an image.

The phase image formed in step S5 is stored in the storage unit 20 as the OCT data 21. FIG.

(S6: Obtain blood flow data for each blood vessel position)
For each of a plurality of blood vessel positions (that is, a plurality of cross-sections of interest), the blood flow data generator 33, based on the inclination angle of the blood vessel of interest obtained in step S4 and the phase image formed in step S5, Blood flow data is generated for the blood vessel of interest passing through the cross section of interest. This blood flow data includes, for example, data representing time-series changes in blood flow in the vessel of interest. Examples of such data include time-series changes in blood flow velocity during the measurement period of the OCT blood flow measurement performed in step S2 (typically, a period longer than one cardiac cycle), and time-series changes in blood flow volume per unit time.

The blood flow data generated in step S6 is stored in the storage unit 20 as the OCT data 21. FIG.

(S7: Create a blood flow graph for each blood vessel position)
For each of a plurality of blood vessel positions (that is, a plurality of cross sections of interest), the display control unit 13 creates a blood flow graph representing the fundus blood flow dynamics of the eye to be examined based on the blood flow data generated in step S6. . This blood flow graph represents time-series changes in blood flow in the target blood vessel in the target cross section.

The blood flow graph creation process includes, for example, the following processes.
(1) The blood flow data (for example, blood flow velocity or blood flow volume per unit time) generated in step S6 is represented by the horizontal axis (first coordinate axis) representing time t and the vertical axis (second coordinate axis). (2) A process of connecting the plotted point groups with a line.

Here, the values of the plotted point cloud (that is, the values on the vertical axis) are, for example, the values of a plurality of pixels (that is, blood values corresponding to the magnitude of the flow velocity, etc.). This statistic may be, for example, mean, median, mode, maximum, minimum, and the like. Alternatively, the value on the vertical axis may be the value of a predetermined pixel (for example, the pixel located at the center, the pixel located at the center of gravity, etc.) in the target blood vessel section at the corresponding time phase.

The process of connecting the plotted point groups with lines includes the process of connecting temporally adjacent points with lines. Lines connecting adjacent points may be straight or curved. When the connection line is a curve, for example, it is possible to apply any approximation curve (eg, spline curve, Bezier curve, etc.) with plotted point groups as control points. Also, the point group may be interpolated by applying Lagrangian interpolation or the like.

(S8: Synchronize multiple blood flow graphs with each other)
The synchronization processing unit 12 applies, for example, the synchronization processing described above to the plurality of blood flow graphs created in step S7.

(S9: Display front image, measurement position information, and blood flow graph)
The display control unit 13 controls the front image of the fundus acquired in step S1, a plurality of measurement position information indicating a plurality of blood vessel positions to which OCT blood flow measurement is applied, and a plurality of blood flow graphs created in step S7. and at least one of them are displayed on the display device 2.

A plurality of pieces of measurement position information are displayed together with the front image of the fundus. Typically, a plurality of pieces of measurement position information are displayed superimposed on the front image of the fundus. Alternatively, a plurality of pieces of measurement position information are displayed near the front image of the fundus.

Several examples will be described for association between the front image of the fundus and multiple blood vessel positions (typically, determination of the display positions of the plurality of measurement position information in the front image of the fundus). Note that the method of associating the front image of the fundus and the positions of the plurality of blood vessels is not limited to the following example.

In the first example, a plurality of blood vessel positions for a predetermined fundus front image (for example, a front image acquired in step S1 or at an arbitrary timing, or an image that can be associated (registered) with this) is set, and the OCT blood flow measurement of step S2 is applied to these vessel locations. OCT blood flow measurement for a plurality of set blood vessel positions is performed, for example, through a plurality of processes such as the following: Observation of the fundus (that is, repetitive acquisition of front images) in parallel with OCT blood flow measurement. executing registration between the obtained fundus observation image and the above-described predetermined fundus frontal image; using the results of this registration to align each of the plurality of blood vessel positions to positions in the fundus observation image. Transform; apply OCT blood flow measurements to the locations set in the fundus observation image. In this example, for each of a plurality of blood vessel positions set for a predetermined fundus front image, the blood flow data obtained by OCT blood flow measurement applied to the position corresponding to the blood vessel position is Based blood flow graphs are associated.

In a second example, fundus observation is performed in parallel with OCT blood flow measurement. A plurality of positions (that is, a plurality of blood vessel positions) to which OCT blood flow measurement is applied are recorded as positions (coordinates) in the fundus observation image obtained by fundus observation. Registration is performed between this fundus observation image and the front image of the fundus acquired in step S1 or the like. Through the result of this registration, each of the multiple blood vessel positions recorded with the fundus observation image is transformed into a position in the frontal image of the fundus. In this example, the blood flow graph at each of a plurality of blood vessel positions to which OCT blood flow measurement is applied is associated with the position in the front image corresponding to the blood vessel position.

FIG. 4 shows an example of information displayed in step S9. Reference numeral 110 is the front image of the fundus acquired in step S1. Reference numerals 121, 122, 123, 124, 125, and 126 correspond to a plurality of measurement position information, and indicate a plurality of blood vessel positions to which OCT blood flow measurement is applied in step S2. That is, each of the measurement position information 121 to 126 indicates the position of the B section to which the main scan is applied. This example shows the case where OCT blood flow measurement is applied to six blood vessel locations in the fundus.

In this example, in step S7, six blood flow graphs 141, 142, 143, 144, 145 and 146 corresponding to six blood vessel positions indicated by six pieces of measurement position information 121-126 are created. The six created blood flow graphs 141-146 are synchronized with each other in step S8. Each of blood flow graphs 141 to 146 in this example represents time-series changes in blood flow velocity (v).

In this example, the display control unit 13 further displays related information that visually associates the six pieces of measurement position information 121-126 with the six blood flow graphs 141-146. “Visually associating” means, for example, presenting the correspondence relationship between the measurement position information and the blood flow graph so as to be visually recognizable.

The related information in this example includes common incidental information presented in the vicinity of each corresponding measurement position information and blood flow graph. Specifically, for the measurement position information 121 and the blood flow graph 141 that correspond to each other, additional information "A" 131 is presented near the measurement position information 121, and additional information "A" 151 common to this is presented. is presented near blood flow graph 141 .

Similarly: for the measurement position information 122 and the blood flow graph 142 that correspond to each other, the additional information "B" 132 is presented near the measurement position information 122, and the additional information "B" 152 that is common with this is the blood flow graph. Presented near the flow graph 142; for the measurement position information 123 and the blood flow graph 143 that correspond to each other, the accompanying information "C" 133 is presented near the measurement position information 123, and common with this Supplementary information “C” 153 is presented near blood flow graph 143 ; Supplementary information “D” 134 is presented near measurement position information 124 for measurement position information 124 and blood flow graph 144 that correspond to each other. and common incidental information "D" 154 is presented near the blood flow graph 144; Supplementary information "E" 135 is presented, and supplementary information "E" 155 common to this is presented near the blood flow graph 145; Supplementary information “F” 136 is presented near the measurement position information 126 , and supplementary information “F” 156 common to this is presented near the blood flow graph 146 .

The supplementary information 151 to 156 in this example includes alphabets, but the supplementary information is not limited to this. For example, the collateral information may include other types of character strings (eg, numbers, national characters, etc.). Also, the incidental information may include image information such as marks.

With such incidental information (related information), the user can easily grasp the correspondence relationship between the blood vessel position to which OCT blood flow measurement is applied (that is, the position indicated by the measurement position information) and the blood flow graph. . For example, a user can easily identify a blood flow graph obtained as a result of an OCT blood flow measurement at a certain blood flow location. Conversely, the user can easily grasp which blood vessel position measurement result is represented by a certain blood flow graph. In general, similar effects can be obtained when an arbitrary number of pieces of measurement position information and an arbitrary number of blood flow graphs are displayed.

Another example of information displayed in step S9 is shown in FIG. Reference numeral 110 is the front image of the fundus acquired in step S1. Reference numerals 161, 162, 163, 164, 165 and 166 correspond to a plurality of pieces of measurement position information and indicate a plurality of blood vessel positions to which OCT blood flow measurement was applied in step S2.

Also in this example, six blood flow graphs 171, 172, 173, 174, 175 and 176 are created corresponding to the six blood vessel positions indicated by the six measurement position information 161-166. The six created blood flow graphs 171-176 are synchronized with each other in step S8. Each of blood flow graphs 171 to 176 in this example represents time-series changes in blood flow velocity (v).

In this example, the display control unit 13 displays related information different from the example shown in FIG. The related information in this example is color information attached to the measurement position information 161-166 and the blood flow graphs 171-176. Specifically, the display control unit 13 displays the measurement position information and the blood flow graph that correspond to each other in a common color. For example: the measurement position information 161 and the blood flow graph 171 corresponding to each other are displayed in common black; the measurement position information 162 and blood flow graph 172 corresponding to each are displayed in common red; The measurement position information 163 and the blood flow graph 173 that correspond to each other are displayed in common blue; the measurement position information 164 and blood flow graph 174 that correspond to each other are displayed in common yellow; The corresponding measurement position information 165 and blood flow graph 175 are displayed in common green; the measurement position information 166 and blood flow graph 176 corresponding to each other are displayed in common orange.

Such incidental information (related information) also allows the user to easily grasp the correspondence relationship between the blood vessel position to which the OCT blood flow measurement is applied (that is, the position indicated by the measurement position information) and the blood flow graph. can.

An example of information display control will be described with reference to FIGS. 6A and 6B. Reference numeral 110 is the front image of the fundus acquired in step S1. Also, reference numerals 181, 182, 183, 184, 185 and 186 correspond to a plurality of measurement position information and indicate a plurality of blood vessel positions to which OCT blood flow measurement is applied in step S2.

Also in this example, six blood flow graphs 191, 192, 193, 194, 195 and 196 corresponding to six blood vessel positions indicated by six measurement position information 181-186 are created. The six created blood flow graphs 191-196 are synchronized with each other in step S8. Each of blood flow graphs 191 to 196 in this example represents time-series changes in blood flow velocity (v).

In this example, first, all blood flow graphs 191 to 196 are displayed. At this stage, any one or more of the blood flow graphs 191 to 196 may be displayed.

The user selects desired measurement position information from the measurement position information 181 to 186 using the operation unit 50 . This selection operation is, for example, an operation of clicking desired measurement position information using a pointing device such as a mouse.

Also, in this example, it is assumed that the measurement position information corresponding to the blood flow graph already displayed on the display device 2 is selected. For example, in the example shown in FIG. 6A, since all six blood flow graphs 191-196 are already displayed, one of the six measurement position information 181-186 is selected. A case where measurement position information corresponding to a blood flow graph that is not currently displayed on the display device 2 is selected will be described in the following example.

When the user selects desired measurement position information, the display control unit 13 changes the display mode of the blood flow graph corresponding to the selected measurement position information. This control includes, for example, control for changing the display mode of the blood flow graph itself corresponding to the selected measurement position information, and/or the surroundings (or vicinity) of the blood flow graph corresponding to the selected measurement position information. ) includes a control to change the display mode.

Examples of control for changing the display mode of the blood flow graph itself include control for changing the color of the blood flow graph, control for changing the thickness of the blood flow graph, control for changing the thickness of the blood flow graph, type of line of the blood flow graph (solid line, dotted line, dashed line, etc.). ), control to change the previous density of the blood flow graph, and the like.

Examples of control for changing the display mode around (or in the vicinity of) the blood flow graph include control for displaying the above-described incidental information in the vicinity of the blood flow graph, control for changing the display color around the blood flow graph, Any of the controls, such as changing the density around the perfusion graph, can be performed.

Along with such a change in the display mode of the blood flow graph, the display control unit 13 controls to change the display mode of the measurement position information selected by the user, and/or around the selected measurement position information (or (neighborhood thereof) may be controlled to change the display mode. The change of the display mode regarding the measurement position information is performed, for example, in the same manner as the change of the display mode regarding the blood flow graph.

For example, the display control unit 13 changes the display color of the selected measurement position information and the display color of the corresponding blood flow graph to the same color. FIG. 6B shows an example in which the user selects the measurement position information 182 and the display control unit 13 changes the display mode of the measurement position information 182 and the corresponding display mode of the blood flow graph 192 .

In another example, the display control unit 13 displays the same incidental information near the selected measurement position information and near the corresponding blood flow graph.

According to such display control, the user can select a desired blood vessel position (that is, the position indicated by the measurement position information), and furthermore, the correspondence relationship between the selected blood vessel position and the blood flow graph can be easily established. can be grasped.

An example of information display control will be described with reference to FIGS. 7A and 7B. Reference numeral 110 is the front image of the fundus acquired in step S1. Reference numerals 201, 202, 203, 204, 205, and 206 correspond to a plurality of measurement position information, and indicate a plurality of blood vessel positions to which OCT blood flow measurement is applied in step S2.

Also in this example, six blood flow graphs 211, 212, 213, 214, 215 and 216 corresponding to the six blood vessel positions indicated by the six pieces of measurement position information 201-206 are created. The six created blood flow graphs 211-216 are synchronized with each other in step S8. Each of blood flow graphs 211 to 216 in this example represents time-series changes in blood flow velocity (v).

None of the blood flow graphs 191-196 are displayed at the stage shown in FIG. 7A. At this stage, part of the blood flow graphs 191 to 196 may be displayed.

The user selects desired measurement position information from the measurement position information 201 to 206 using the operation unit 50 . This selection operation is, for example, an operation of clicking desired measurement position information using a pointing device such as a mouse. In this example, it is assumed that measurement position information corresponding to a blood flow graph not displayed on the display device 2 is selected at the stage of the selection operation. For example, in the example shown in FIG. 7A, none of the six blood flow graphs 211-216 are displayed, so one of the six measurement position information 201-206 is selected. The case where the measurement position information corresponding to the blood flow graph already displayed on the display device 2 is selected has been described with reference to the examples shown in FIGS. 6A and 6B.

When the user selects desired measurement position information, the display control unit 13 causes the display device 2 to display a blood flow graph corresponding to the selected measurement position information. Along with such display control of the blood flow graph, the display control unit 13 controls to change the display mode of the measurement position information selected by the user, and/or controls the surroundings (or the vicinity thereof) of the selected measurement position information. ) may be executed to change the display mode.

In FIG. 7B, the user selects the measurement position information 202 and 204, the display control unit 13 changes the display mode of the measurement position information 202 and 204, and the blood flow graphs 212 and 204 corresponding to these are displayed. It shows an example of the case.

In this example, the display control unit 13 may display the aforementioned related information that visually associates each of the selected pieces of measurement position information with the corresponding blood flow graph.

According to such display control, the user can select a desired blood vessel position (that is, the position indicated by the measurement position information) and observe the blood flow graph. Furthermore, the user can easily grasp the correspondence relationship between the selected blood vessel position and the blood flow graph.

An example of information display control will be described with reference to FIG. In this example, the blood flow parameter is blood flow per unit time, and the blood flow graph represents time-series changes in blood flow per unit time.

In this case, the display control unit 13 controls the plurality of blood vessel positions (of which the OCT blood flow measurement is applied) based on the plurality of blood flow data corresponding to the plurality of blood vessel positions to which the OCT blood flow measurement is applied. It is possible to display a total blood flow graph that represents time-series changes in blood flow per unit time in at least two blood vessel positions. In other words, the display control unit 13 can display time-series changes in values calculated from two or more blood flow volumes obtained for two or more blood vessel positions. This value may be any statistic that can be calculated from two or more blood flows. This statistical value is, for example, a sum of two or more blood flows (total blood flow), an average value of two or more blood flows (average blood flow), two or more variations in blood flow (standard deviation, variance, etc.), 2 It may be the maximum value or the minimum value among the above blood flow volumes. Note that when the sum of a plurality of blood flow volumes corresponding to all of a plurality of blood vessel positions to which OCT blood flow measurement is applied is calculated, a time-series change in the total blood flow volume is obtained as a blood flow parameter, and is measured for a predetermined period of time. Integrating over gives the total blood flow.

An example of information displayed in this example is shown in FIG. Similar to the example shown in FIG. 4, in this example, a front image 110 of the fundus, a plurality of pieces of measurement position information 221, 222, 223, 224, 225 and 226, a plurality of blood flow graphs 241, 242, 243 and 244 , 245 and 246 are displayed. Furthermore, as in the example shown in FIG. 4, related information that associates the plurality of pieces of measurement position information 221-246 with the plurality of blood flow graphs 241-246 is displayed. Specifically, the related information includes incidental information groups 231, 232, 233, 234, 235 and 236 displayed near the respective pieces of measurement position information 221, 222, 223, 224, 225 and 226, and a plurality of and additional information groups 251, 252, 253, 254, 255 and 256 displayed near blood flow graphs 241, 242, 243, 244, 245 and 246, respectively.

However, unlike the blood flow graphs 141 to 146 shown in FIG. 4, each of the blood flow graphs 241 to 246 in this example represents time series changes in blood flow Q per unit time.

When the blood flow parameter is the blood flow volume per unit time as in this example, the display control unit 13 displays a plurality of blood flow parameters corresponding to a plurality of blood vessel positions (that is, positions indicated by the plurality of measurement position information 221 to 226). Based on the data (for example, multiple blood flow graphs 241 to 246), a total blood flow graph 240 can be displayed that represents time series changes in the sum of blood flow per unit time at multiple blood vessel positions. As described above, a graph (statistical value graph) representing time-series changes in arbitrary statistical values such as average blood flow may be displayed.

In the example shown in FIG. 8, the total blood flow graph 240 is displayed together with the blood flow graphs 241 to 246, but the display mode of the statistical value graph is not limited to this. For example, a statistical value graph may be displayed together with one or more blood flow graphs, or only a statistical value graph may be displayed.

Information indicating the contribution of each blood flow graph (or any two or more blood flow graphs) in the statistical value graph can be displayed. For example, near each blood flow graph and/or near each piece of measurement position information, information indicating the contribution to the total blood flow in percentage or the like can be displayed. Also, information indicating the magnitude of the contribution to the statistical value can be displayed. For example, it is possible to set the display color of each blood flow graph and/or the display color of each measurement position information according to the size of the contribution to the total blood flow.

In order to compare two or more blood flow data (such as blood flow graphs), an oscillatory analysis can be applied to each of these blood flow data and the results can be represented graphically. For vibration analysis, for example, a complex Fourier transform or a fast Fourier transform can be used. Also, the vibration analysis graph is configured, for example, so that the horizontal axis indicates the vibration mode (frequency mode) and the vertical axis indicates the amplitude or intensity. Vibration analysis graphs can be displayed in addition to or instead of the blood flow graphs described above. It is also possible to obtain the number of vibration modes and the intensity (amplitude) of each vibration mode by analyzing the vibration analysis graphs, and to compare between two or more vibration analysis graphs.

Another example of information display control will be described. In this example, the display control unit 13 changes the display color of the blood vessel image (blood vessel region) in the front image of the fundus in accordance with the blood flow data (or blood flow graph based thereon) obtained by OCT blood flow measurement. Control. As a result, a thermographic-like image representing the distribution of blood flow dynamics in the fundus of the subject's eye is obtained.

Furthermore, the display control unit 13 changes the display colors of the plurality of blood vessel images in the front image of the fundus in chronological order based on the chronological change in the blood flow parameter in the blood flow data (or the blood flow graph based thereon). can be changed. As a result, time-series images are obtained, which represent time-series changes in the distribution of blood flow dynamics in the fundus of the subject's eye, just like dynamic thermography.

In order to display such an image, for example, the ophthalmologic imaging apparatus 1 stores in advance a lookup table (LUT) that associates blood flow parameter values with display colors.

The display control unit 13 specifies, for example, an image of a blood vessel corresponding to blood flow data (or a blood flow graph based thereon) (that is, a blood vessel to which OCT blood flow measurement was applied to create the blood flow graph). do. A blood vessel image corresponding to the blood flow data (or a blood flow graph based thereon) is thereby identified. This specific processing includes any image processing such as thresholding, edge detection, region growing, labeling. Thereby, a connected image region (blood vessel image) corresponding to each blood vessel is specified.

Crossing of blood vessels can be considered in identifying connected image regions. For example, blood vessel crossings can be detected from changes in blood vessel diameter determined from a fundus frontal image or an angiogram (motion contrast image). It is also possible to detect crossings of blood vessels from a three-dimensional angiogram.

The display control unit 13 determines the display color of the corresponding blood vessel image based on each of the plurality of blood flow data (or the blood flow graph based thereon) and the lookup table. More specifically, the display control unit 13 identifies the display color corresponding to the value indicated by the blood flow data (or blood flow graph based thereon) from the lookup table.

Note that two or more blood vessel positions may be set for a single blood vessel. In other words, two or more blood vessel positions may be set for the same blood vessel. In such a case, one blood vessel image can be divided into two or more partial images, and a display color can be determined for each partial image. Also, from two blood flow data (or two blood flow graphs based thereon) at two different blood vessel positions, it is possible to estimate changes in blood flow parameter values between two blood vessel positions. Further, the display color corresponding to the intermittently or continuously changing estimates thus obtained can be determined based on a lookup table.

A similar estimation process can be applied to any blood vessel regardless of the number of set blood vessel positions. The estimation processing in this case is performed based on various morphological parameters related to blood vessels, such as changes in blood vessel diameter, length of blood vessels, positions of branches, number of branches, and the like.

Such information display control enables the user to intuitively grasp the distribution of blood flow parameters.

Still another example of information display control will be described. In this example, the arteries and veins of the fundus are displayed in different colors. A configuration example for that purpose is shown in FIG. FIG. 9 shows the control section 10A. The controller 10A is applied, for example, in place of the controller 10 in FIG. The control unit 10A includes a blood vessel classification unit 14. FIG. A blood vessel classification unit 14 classifies a plurality of blood vessel images depicted in the front image of the fundus into arteries based on a plurality of blood flow data corresponding to a plurality of blood vessel positions (or a plurality of blood flow graphs based thereon). The images are classified into corresponding images (arterial images) and images corresponding to veins (vein images).

The processing executed by the blood vessel classification unit 14 is determined according to, for example, the type of image to be analyzed. Note that the blood vessel classification unit 14 may be configured to switch the processing to be executed according to the type of image to be analyzed (for example, the type of modality). An example of blood vessel classification (artery/vein determination) will be described below, but the present invention is not limited to these.

When the image to be analyzed is a fundus photograph, the blood vessel classification unit 14 can perform artery/vein determination, for example, based on the degree of brightness (hyperreflexia) in the axial line portion of the blood vessel image. .

When the image to be analyzed is a phase image obtained by OCT blood flow measurement, the blood vessel classification unit 14 can perform artery/vein determination based on blood flow dynamics and the direction of blood flow. For example, artery/vein determination can be performed based on the shape of the blood flow graph (amplitude, wave height, mean, maximum, minimum, frequency, wavelength, etc.). Further, based on the determination result regarding one blood vessel, the direction of blood flow in the one blood vessel, and the direction of blood flow in the other blood vessel, the artery/vein determination of the other blood vessel can be performed.

The display control unit 13 displays the artery image and the vein image classified by the blood vessel classification unit 14 in different colors. For example, an artery image can be displayed in red and a vein image can be displayed in blue.

According to such information display control, the user can intuitively distinguish between arteries and veins in the fundus. Furthermore, the blood flow dynamics of arteries and the blood flow dynamics of veins can be easily grasped.

Another example will be described. For arterial images, a warm-color lookup table corresponding to blood flow data (or a blood flow graph based thereon) is set in advance. Furthermore, for the vein image, a cool color lookup table corresponding to blood flow data (or a blood flow graph based thereon) is set in advance.

The display control unit 13 determines the display color of each classified arterial image based on the blood flow data (or blood flow graph based thereon) and the warm color lookup table. Further, the display control unit 13 determines the display color of each classified vein image based on the blood flow data (or the blood flow graph based thereon) and the cool color lookup table. Furthermore, the display control unit 13 displays the artery image and the vein image in the determined display colors.

The ophthalmologic imaging apparatus 1 and modifications thereof described above are basically configured to be capable of both acquisition of a front image of the fundus (fundus imaging) and OCT blood flow measurement. On the other hand, the ophthalmologic imaging apparatus according to the embodiment may be capable of executing only one of acquisition of a front image (fundus imaging) and OCT blood flow measurement.

A case of acquiring a front image from the outside will be described. In this example, as in the above embodiment, the fundus frontal image includes a color fundus image, a monochrome fundus image, a fluorescence fundus image, an OCT cross-sectional image (C scan image), an OCT projection image, an OCT shadowgram, and an OCT blood vessel. It can be any of the enhanced images. Alternatively, the fundus front image of this example may be an image obtained by fundus fluorescence imaging (for example, fluorescein fluorescence imaging, indocyanine green fluorescence imaging, autofluorescence imaging, etc.).

FIG. 10 shows a configuration example of an ophthalmologic imaging apparatus according to this example. Similar to the ophthalmic imaging apparatus 1 of the above embodiment, the ophthalmic imaging apparatus 1A applies OCT blood flow measurement to each of a plurality of blood vessel positions in the fundus of the subject's eye to obtain a plurality of blood vessel positions corresponding to the plurality of blood vessel positions. Blood flow data can be acquired. Further, the ophthalmologic photographing apparatus 1A includes a front image receiving section 70 that receives a front image of the fundus from the outside, unlike the above embodiment. The front image reception unit 70 may include, for example, a communication interface for performing data communication with an external device, a device for reading data from a recording medium, and the like. Components other than the front image reception unit 70 may be the same as corresponding components in the ophthalmologic photographing apparatus 1 .

On the other hand, FIG. 11 shows an example of an ophthalmologic imaging apparatus configured to acquire blood flow data from the outside. The ophthalmologic imaging apparatus 1B includes a front image acquisition unit 60 that acquires a front image of the fundus of the subject's eye, like the ophthalmologic imaging apparatus 1 of the above-described embodiment. Further, the ophthalmologic imaging apparatus 1B includes a blood flow data reception unit 80 unlike the above embodiment. The blood flow data receiving unit 80 receives a plurality of blood flow data corresponding to a plurality of blood vessel positions obtained by applying OCT blood flow measurement to each of a plurality of blood vessel positions in the fundus of the subject's eye. The blood flow data reception unit 80 may include, for example, a communication interface for performing data communication with an external device, a device for reading data from a recording medium, and the like. Components other than the blood flow data reception unit 80 may be the same as corresponding components in the ophthalmologic imaging apparatus 1 .

In the embodiment shown in FIGS. 10 and 11, for example, the display control unit 13 performs registration between an OCT projection image (or a frame of a fundus observation image, etc.) and a front image. may be configured to associate blood vessel positions (that is, display positions of measurement position information) with blood flow graphs using the result of the above.

<Ophthalmic information processing device>
An ophthalmologic information processing apparatus according to an exemplary embodiment will be described. FIG. 12 shows a configuration example of the ophthalmologic information processing apparatus of this embodiment. The ophthalmologic information processing apparatus 300 stores fundus data and the like acquired using OCT, and displays various information based on the stored data.

The ophthalmologic information processing apparatus 300 can display various types of information such as a fundus front image, blood flow information, and a blood vessel-enhanced image on the display device 2 . The display device 2 may be a part of the ophthalmologic information processing apparatus 300 or may be an external device connected to the ophthalmologic information processing apparatus 300 . In addition, the ophthalmologic information processing apparatus 300 can send various types of information to computers, storage devices, ophthalmologic apparatuses, and the like.

The ophthalmologic information processing apparatus 300 includes a control section 310 , a storage section 320 , a data processing section 330 , a data input section 340 and an operation section 350 . Control unit 310 includes a synchronization processing unit 312 and a display control unit 213 . At least OCT data 321 is stored in the storage unit 320 . The storage unit 320 may also store front images such as fundus photographs. Note that when the front image is an OCT image, the front image is included in the OCT data 321 .

Each element of the ophthalmologic information processing apparatus 300 has, for example, the same configuration and function as the corresponding element in the ophthalmologic imaging apparatus 1 described above. That is, the control unit 310 has the same configuration and functions as the control unit 10, the synchronization processing unit 312 has the same configuration and functions as the synchronization processing unit 12, and the display control unit 313 has the same configuration and functions as the display control unit 13. The storage unit 320 has the same configuration and functions as the storage unit 20 , and the operation unit 350 has the same configuration and functions as the operation unit 50 .

The OCT data 321 may be data in the same form as the OCT data 21 . For example, the OCT data 321 may include any one or more of (1) to (5) below.
(1) Data collected by OCT scanning of the fundus (raw data)
(2) Image data obtained by processing raw data (3) Intermediate data obtained during a series of processes for generating image data from raw data (4) Obtained by processing raw data Blood flow data (5) Intermediate data obtained during a series of processes for generating blood flow data from raw data

The data processing unit 330 executes various data processing. The data processing section 330 may have the same configuration and functions as at least part of the image forming section 32 . Also, the data processing section 330 may have the same configuration and functions as at least part of the blood flow data generating section 33 .

The data input unit 340 inputs the OCT data 321 and/or its source data to the ophthalmologic information processing apparatus 300 from the outside. When the front image of the fundus is not an OCT image (for example, when the front image is a photograph of the fundus), the data input unit 340 inputs the front image of the fundus separately from the OCT data 321 and/or its original data. Input to the ophthalmic information processing apparatus 300 from the outside. The data input unit 340 may include, for example, a communication interface for data communication with an external device, a device for reading data from a recording medium, and the like.

The display control unit 313 executes the following display controls: display a front image; display a plurality of measurement position information indicating a plurality of blood vessel positions to which OCT blood flow measurement is applied, together with the front image; Based on at least one of the data, at least one blood flow graph, each representing a time-series change in a predetermined blood flow parameter, is displayed in parallel with the en face image.

In the embodiment shown in FIG. 12, for example, the display control unit 313 performs registration between an OCT projection image (or a frame of a fundus observation image, etc.) and a front image, and uses the result of this registration. and the blood vessel position (that is, the display position of the measurement position information) and the blood flow graph are associated with each other.

〈Action and effect〉
Actions and effects of the ophthalmic photographing apparatus and the ophthalmic information processing apparatus according to the exemplary embodiment described above will be described.

In an exemplary embodiment, the ophthalmic imaging apparatus (1) includes a blood flow data acquisition unit (OCT data acquisition unit 30), a front image acquisition unit (60), and a display processing unit (display control unit 13, etc.). include. The blood flow data acquisition unit applies OCT blood flow measurement to the fundus of the subject's eye to acquire a plurality of blood flow data corresponding to a plurality of blood vessel positions. The front image acquisition unit acquires a front image of the fundus of the subject's eye. The display processing unit causes the display means (display device 2) to display information.

Specifically, the display processing unit displays the front image (110) acquired by the front image acquiring unit. Furthermore, the display processing unit displays a plurality of measurement position information (121 to 126, etc.) indicating a plurality of blood vessel positions to which OCT blood flow measurement is applied together with the front image. In addition, the display processing unit displays at least one blood flow graph (141 to 146, etc.) each representing a time-series change in a predetermined blood flow parameter based on at least one of the plurality of blood flow data, It is displayed in parallel with the front image.

In another exemplary embodiment, the ophthalmologic imaging apparatus (1A) includes a blood flow data acquisition section (OCT data acquisition section 30), a front image reception section (70), and a display processing section (display control section 13, etc.). including. The blood flow data acquisition unit applies OCT blood flow measurement to the fundus of the subject's eye to acquire a plurality of blood flow data corresponding to a plurality of blood vessel positions. The front image receiving unit receives a front image of the fundus of the subject's eye from the outside. The display processing unit causes the display means (display device 2) to display information.

Specifically, the display processing unit displays the front image accepted by the front image accepting unit. Further, the display processing unit displays a plurality of measurement position information indicating a plurality of blood vessel positions to which OCT blood flow measurement is applied together with the front image. In addition, the display processing unit displays at least one blood flow graph each representing a time-series change in a predetermined blood flow parameter based on at least one of the plurality of blood flow data, in parallel with the front image. display.

In yet another exemplary embodiment, an ophthalmologic imaging apparatus (1B) includes a blood flow data reception unit (80), a front image acquisition unit (60), and a display processing unit (such as the display control unit 13). . The blood flow data reception unit receives a plurality of blood flow data corresponding to a plurality of blood vessel positions acquired by applying OCT blood flow measurement to each of a plurality of blood vessel positions in the fundus of the subject's eye. The front image acquisition unit acquires a front image of the fundus of the subject's eye. The display processing unit causes the display means (display device 2) to display information.

Specifically, the display processing section displays the front image acquired by the front image acquiring section. Further, the display processing unit displays a plurality of measurement position information indicating a plurality of blood vessel positions to which OCT blood flow measurement is applied together with the front image. In addition, the display processing unit displays at least one blood flow graph each representing a time-series change in a predetermined blood flow parameter based on at least one of the plurality of blood flow data, in parallel with the front image. display.

According to these embodiments, the user can grasp the position where the OCT blood flow measurement is applied from the measurement position information displayed together with the front image, and further grasp the blood flow dynamics at that position from the blood flow graph. can be done. In particular, according to these embodiments, it is possible to present in a suitable manner a plurality of pieces of blood flow information obtained by applying OCT blood flow measurement to a plurality of blood vessels in the fundus of the subject's eye. As a result, it is possible to facilitate diagnosis and screening based on blood flow information of a plurality of fundus blood vessels, and to improve the accuracy and accuracy of diagnosis and screening.

In an embodiment, the display processing unit may be configured to display in parallel a plurality of blood flow graphs corresponding to a plurality of blood vessel positions to which OCT blood flow measurement is applied.

According to such a configuration, it is possible to support comprehensive understanding of the blood flow dynamics of the fundus from a plurality of blood flow graphs corresponding to a plurality of blood vessel positions.

Note that the display processing unit selectively displays one or more blood flow graphs among a plurality of blood flow graphs corresponding to a plurality of blood vessel positions to which OCT blood flow measurement is applied (and two or more blood flow graphs). in parallel).

In an embodiment, the display processing unit visually displays each of at least one blood flow graph displayed on the display means and measurement position information indicating a blood vessel position corresponding to this (or these) blood flow graph. It may be configured to display related information to be associated.

According to such a configuration, the user can easily grasp the correspondence relationship between the blood vessel positions on the fundus and the blood flow graph by referring to the related information.

In the embodiment, the display processing unit may be configured to display, as related information, common incidental information near the measurement position information and the blood flow graph that correspond to each other.

According to such a configuration, the user can easily determine the correspondence relationship between the blood vessel positions on the fundus and the blood flow graph by referring to the common incidental information assigned to the measurement position information and the blood flow graph. It is possible to grasp

In the embodiment, the display processing section may be configured to display the measurement position information and the blood flow graph that correspond to each other as related information in a common color.

According to such a configuration, the user can easily grasp the correspondence relationship between the blood vessel positions on the fundus and the blood flow graph by referring to the display color of the measurement position information and the display color of the blood flow graph. It is possible.

An ophthalmic imaging device according to an exemplary embodiment may further include an operating unit. Further, the display processing section may be configured to display the blood flow graph corresponding to the selected measurement position information when any one of the plurality of pieces of measurement position information is selected using the operation section.

According to such a configuration, the user can observe the blood flow graph at the desired blood vessel position simply by specifying the desired blood vessel position in the fundus of the subject's eye. This makes it possible to facilitate and facilitate the work for diagnosis and screening.

An ophthalmic imaging device according to an exemplary embodiment may further include an operating unit. Furthermore, when the measurement position information corresponding to the already displayed blood flow graph is selected from the plurality of pieces of measurement position information using the operation unit, the display processing unit displays the blood flow corresponding to the selected measurement position information. It may be configured to change the display mode of the flow graph.

According to such a configuration, the user can easily identify the blood flow graph at the desired blood vessel position simply by specifying the desired blood vessel position in the fundus of the subject's eye. This makes it possible to facilitate and facilitate the work for diagnosis and screening.

In an embodiment, the blood flow graph is represented by a two-dimensional orthogonal coordinate system in which a first coordinate axis indicates time and a second coordinate axis indicates a blood flow parameter, either blood flow velocity or blood flow volume per unit time. It may be configured as follows.

According to such a configuration, it is possible to present time-series changes in blood flow velocity and time-series changes in blood flow per unit time as graphs. As a result, the user can easily comprehend time-series changes in blood flow velocity and time-series changes in blood flow volume per unit time.

In the embodiment, when the blood flow parameter is the blood flow volume per unit time, the display processing unit displays the total blood flow volume representing the time-series change of the blood flow volume per unit time at the plurality of blood vessel positions based on the plurality of blood flow data. It may be configured to display a flow rate graph.

With such a configuration, it is possible to grasp not only the blood flow dynamics of a plurality of blood vessels, but also the integrated blood flow dynamics of the plurality of blood vessels.

The ophthalmologic imaging apparatus according to the exemplary embodiment may further include a synchronization processor that synchronizes at least one of the plurality of blood flow data and the plurality of blood flow graphs corresponding thereto.

According to the configuration for synchronizing a plurality of blood flow data corresponding to a plurality of blood vessel positions, various types of processing can be executed using a plurality of synchronized blood flow data, thereby improving the accuracy and accuracy of diagnosis and screening. It becomes possible to plan According to the configuration that synchronizes a plurality of blood flow graphs, it is possible to display a plurality of blood flow graphs whose positions in the time series direction are adjusted, so that it is possible to improve the accuracy and accuracy of diagnosis and screening. Become.

The ophthalmic imaging apparatus according to the exemplary embodiment may further include a reception section (data input section 40). The data input unit 40 receives biological information of the subject that changes in time series from the biological information monitor while the blood flow data acquisition unit is applying OCT blood flow measurement to a plurality of blood vessel positions. Further, the synchronization processing section may be configured to synchronize at least one of the plurality of blood flow data and the plurality of blood flow graphs corresponding thereto based on the biological information received by the reception section.

According to such a configuration, it is possible to perform synchronization processing for at least one of a plurality of pieces of blood flow data and a plurality of blood flow graphs corresponding thereto based on biological information of the subject. By referring to the subject's biological information in this way, it is possible to improve the accuracy and reliability of the synchronization process.

In the embodiment, the synchronization processing unit extracts feature values from each of the plurality of blood flow data, and generates at least one of the plurality of blood flow data and the plurality of blood flow graphs corresponding thereto based on the extracted feature values. may be configured to be synchronized with each other.

According to such a configuration, it is possible to perform synchronization processing for at least one of a plurality of pieces of blood flow data and a plurality of blood flow graphs corresponding thereto based on the feature values of the blood flow data. By referring to the characteristic values of blood flow data in this way, it is possible to improve the accuracy and accuracy of synchronization processing.

In an embodiment, the synchronization processor may be configured to synchronize at least one of the plurality of blood flow data and the plurality of blood flow graphs corresponding thereto based on the waveforms of the plurality of blood flow graphs.

According to such a configuration, synchronous processing for at least one of a plurality of blood flow data and a plurality of blood flow graphs corresponding thereto can be performed based on the waveform of the blood flow graph. By referring to the waveform of the blood flow graph in this way, it is possible to improve the accuracy and accuracy of the synchronization processing.

In an embodiment, the display processing unit is configured to color-display a plurality of blood vessel images in a front image corresponding to a plurality of blood vessel positions, based on a plurality of blood flow data or a plurality of blood flow graphs corresponding thereto. It can be.

According to such a configuration, the user can intuitively grasp the distribution state of blood flow dynamics in the fundus of the subject's eye by referring to the display colors of the plurality of blood vessel images.

In the embodiment, the display processing unit is configured to chronologically change display colors of the plurality of blood vessel images based on chronological changes in blood flow parameters in the plurality of blood flow data or the plurality of blood flow graphs. It's okay.

According to such a configuration, the user can intuitively see time-series changes in the distribution state of blood flow dynamics in the fundus of the subject's eye by referring to time-series changes in display colors of a plurality of blood vessel images. It is possible to grasp the

An ophthalmic imaging device according to an exemplary embodiment may further include a vessel classifier (14). The blood vessel classification unit classifies the plurality of blood vessel images into artery images and vein images based on the plurality of blood flow data or the plurality of blood flow graphs. Furthermore, the display processing unit may be configured to display the artery image and the vein image in different colors.

With such a configuration, the user can intuitively distinguish between arteries and veins distributed in the fundus of the subject's eye. Furthermore, the blood flow dynamics of arteries and the blood flow dynamics of veins can be easily grasped.

In the embodiment, the front image is any one of a color fundus image, a monochrome fundus image, a fluorescent fundus image, an OCT cross-sectional image (C-scan image), an OCT projection image, an OCT shadowgram, and an OCT vessel-enhanced image. good.

An ophthalmologic information processing apparatus (300) according to an exemplary embodiment includes a storage unit (320) and a display control unit (313). The storage unit stores a plurality of blood flow data corresponding to a plurality of blood vessel positions acquired by applying OCT blood flow measurement to each of a plurality of blood vessel positions in the fundus of the subject's eye, and a front image of the fundus. do. The display controller causes the display means (display device 2) to display information.

Specifically, the display processing unit displays the front image (110). Furthermore, the display processing unit displays a plurality of measurement position information (121 to 126, etc.) indicating a plurality of blood vessel positions to which OCT blood flow measurement is applied together with the front image. In addition, the display processing unit displays at least one blood flow graph (141 to 146, etc.) each representing a time-series change in a predetermined blood flow parameter based on at least one of the plurality of blood flow data, It is displayed in parallel with the front image.

According to such an embodiment, the user can grasp the position where the OCT blood flow measurement is applied from the measurement position information displayed together with the front image, and further grasp the blood flow dynamics at that position from the blood flow graph. be able to. In particular, according to such an embodiment, it is possible to present a plurality of pieces of blood flow information obtained by applying OCT blood flow measurement to a plurality of blood vessels in the fundus of the subject's eye in a suitable manner. As a result, it is possible to facilitate diagnosis and screening based on blood flow information of a plurality of fundus blood vessels, and to improve the accuracy and accuracy of diagnosis and screening.

Any item described as the above-described ophthalmologic photographing apparatus 1, 1A, or 1B or its modification can be applied to the ophthalmologic information processing apparatus according to the embodiment.

The actions and effects of the embodiments are not limited to these, and actions and effects provided by each item described as the embodiment and actions and effects provided by a combination of a plurality of items should also be considered. In addition, any of the above-described embodiments, other embodiments, known techniques, and the like can be arbitrarily combined in order to obtain desired actions and/or effects, or for other purposes.

The configuration described above is merely an example for suitably implementing the present invention. Therefore, any modification (omission, substitution, addition, etc.) within the scope of the gist of the present invention can be applied as appropriate.

1, 1A, 1B Ophthalmic imaging apparatus 2 Display device 10 Control unit 11 Scan control unit 12 Synchronization processing unit 13 Display control unit 14 Blood vessel classification unit 20 Storage unit 21 OCT data 30 OCT data acquisition unit 31 OCT scanner 32 Image formation unit 33 Blood Flow data generation unit 40 Data input unit 50 Operation unit 60 Front image acquisition unit 70 Front image reception unit 80 Blood flow data reception unit 110 Front images 121, 122, 123, 124, 125, 126 Measurement position information 131, 132, 133, 134, 135, 136 Supplementary information 141, 142, 143, 144, 145, 146 Blood flow graphs 151, 152, 153, 154, 155, 156 Supplementary information 300 Ophthalmic information processing apparatus 310 Control unit 312 Synchronization processing unit 313 Display control unit 320 storage unit 321 OCT data 330 data processing unit 340 data input unit 350 operation unit

Claims (5)

A blood flow data acquisition unit that acquires a plurality of blood flow data corresponding to the plurality of blood vessel positions by applying optical coherence tomography (OCT) blood flow measurement to each of the plurality of blood vessel positions in the fundus of the subject's eye. When,
a front image acquisition unit that acquires a front image of the fundus;
a display processing unit that causes the display means to display information;
The display processing unit
displaying the front image acquired by the front image acquiring unit;
displaying a plurality of measurement position information indicating the plurality of blood vessel positions to which OCT blood flow measurement is applied together with the front image;
displaying in parallel with the front image at least one blood flow graph each representing a time-series change in a predetermined blood flow parameter based on at least one of the plurality of blood flow data;
displaying a plurality of blood vessel images in the front image corresponding to the plurality of blood vessel positions in color according to the blood flow volume, based on the plurality of blood flow data or the plurality of blood flow graphs corresponding thereto;
Ophthalmic imaging equipment. A blood flow data acquisition unit that acquires a plurality of blood flow data corresponding to the plurality of blood vessel positions by applying optical coherence tomography (OCT) blood flow measurement to each of the plurality of blood vessel positions in the fundus of the subject's eye. When,
a front image reception unit that receives a front image of the fundus;
a display processing unit that causes the display means to display information;
The display processing unit
displaying the front image accepted by the front image accepting unit;
displaying a plurality of measurement position information indicating the plurality of blood vessel positions to which OCT blood flow measurement is applied together with the front image;
displaying in parallel with the front image at least one blood flow graph each representing a time-series change in a predetermined blood flow parameter based on at least one of the plurality of blood flow data;
displaying a plurality of blood vessel images in the front image corresponding to the plurality of blood vessel positions in color according to the blood flow volume, based on the plurality of blood flow data or the plurality of blood flow graphs corresponding thereto;
Ophthalmic imaging equipment. Blood flow data for receiving a plurality of blood flow data corresponding to a plurality of blood vessel positions obtained by applying optical coherence tomography (OCT) blood flow measurement to each of a plurality of blood vessel positions in the fundus of an eye to be examined. a reception department;
a front image acquisition unit that acquires a front image of the fundus;
a display processing unit that causes the display means to display information;
The display processing unit
displaying the front image acquired by the front image acquiring unit;
displaying a plurality of measurement position information indicating the plurality of blood vessel positions to which OCT blood flow measurement is applied together with the front image;
displaying in parallel with the front image at least one blood flow graph each representing a time-series change in a predetermined blood flow parameter based on at least one of the plurality of blood flow data;
displaying a plurality of blood vessel images in the front image corresponding to the plurality of blood vessel positions in color according to the blood flow volume, based on the plurality of blood flow data or the plurality of blood flow graphs corresponding thereto;
Ophthalmic imaging equipment. The blood flow is a blood flow per unit time,
The ophthalmic photographing apparatus according to any one of claims 1 to 3. a plurality of blood flow data corresponding to the plurality of blood vessel positions acquired by applying optical coherence tomography (OCT) blood flow measurement to each of the plurality of blood vessel positions in the fundus of the eye to be inspected; a storage unit for storing images;
a display processing unit that causes the display means to display information;
The display processing unit
displaying the front image;
displaying a plurality of measurement position information indicating the plurality of blood vessel positions to which OCT blood flow measurement is applied together with the front image;
displaying in parallel with the front image at least one blood flow graph each representing a time-series change in a predetermined blood flow parameter based on at least one of the plurality of blood flow data;
displaying a plurality of blood vessel images in the front image corresponding to the plurality of blood vessel positions in color according to the blood flow volume, based on the plurality of blood flow data or the plurality of blood flow graphs corresponding thereto;
Ophthalmic information processing device.

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