JP2019042264A - Ophthalmologic imaging apparatus and ophthalmologic information processing apparatus - Google Patents

Abstract

To provide an ophthalmologic imaging apparatus and an ophthalmologic information processing apparatus for satisfactorily comparing eyeground blood flow data of a subject's eye obtained by optical coherence tomography (OCT) blood flow measurement with standard data.SOLUTION: The ophthalmologic imaging apparatus comprises a storage part 20, a data acquisition part 30, and a display control part 13. The storage part stores standard data of eyeground hemodynamics generated in advance. The data acquisition part acquires data by applying OCT blood flow measurement to the eyeground of a subject's eye. The display control part causes display means to display information. The display control part causes the display means to display a blood flow graph expressing time-series variation in a blood flow through a blood vessel in the eyeground on the basis of the data acquired by the data acquisition part. Furthermore, the display control part causes the display means to display standard information based on the standard data, in parallel to the blood flow graph.SELECTED DRAWING: Figure 1

Description

  The embodiment relates to an ophthalmologic imaging apparatus and an ophthalmologic information processing apparatus.

  Diagnostic imaging occupies an important position in the field of ophthalmology. In recent years, utilization of optical coherence tomography (OCT) has been advanced. The OCT has come to be used not only for acquiring B-scan images and three-dimensional images of an eye to be examined but also for acquiring front images (en-face images) such as C-scan images and shadowgrams.

  Furthermore, acquiring the image which emphasized the specific site | part of the to-be-tested eye, and acquiring functional information are also performed. For example, based on time-series data collected by OCT, it is possible to construct a B-scan image in which a fundus blood vessel is emphasized or a front image (referred to as a blood vessel emphasis image, an angiogram, etc.). This technique is called OCT angiography or the like. Further, information on blood flow can be acquired based on phase information of time-series data collected by OCT. This technique is called OCT blood flow measurement or the like.

  In addition, data on an eye to be examined acquired using OCT is compared with standard data to determine the presence or absence of a disease or degree of disease. For example, there is known a technique for comparing the retinal thickness of an eye to be examined obtained by fundus oculi OCT with a standard value of the retinal thickness of a normal eye. However, in the prior art, it is difficult to suitably compare the data of the eye to be examined obtained by the OCT blood flow measurement with the standard data.

JP-A-2015-515894 JP, 2013-184018, A JP, 2011-24930, A

  An object of the embodiment is to provide a technique for suitably comparing fundus blood flow data of an eye to be examined obtained by OCT blood flow measurement with standard data.

  The first aspect of the embodiment acquires data by applying optical coherence tomography (OCT) blood flow measurement to a storage unit that stores standard data of fundus blood flow dynamics created in advance and the fundus of the subject's eye The display processing unit includes a data acquisition unit and a display processing unit that causes a display unit to display information, and the display processing unit changes the time series of the blood flow in the blood vessel of the fundus based on the data acquired by the data acquisition unit. And a standard information based on the standard data is displayed in parallel with the blood flow graph.

  A second aspect of the embodiment is the ophthalmologic imaging apparatus of the first aspect, wherein the display processing unit displays a standard blood flow graph based on the standard data as the standard information.

  A third aspect of the embodiment is the ophthalmologic imaging apparatus of the second aspect, wherein in each of the blood flow graph and the standard blood flow graph, the first coordinate axis indicates time, and the second coordinate axis is blood. It is expressed by a two-dimensional orthogonal coordinate system that indicates the flow velocity or blood flow per unit time.

  A fourth aspect of the embodiment is the ophthalmologic imaging apparatus according to any one of the first to third aspects, wherein the display processing unit displays a statistical value based on the standard data as the standard information.

  A fifth aspect of the embodiment is the ophthalmologic imaging apparatus of any of the first to fourth aspects, wherein the storage unit is a standard data of fundus blood flow dynamics in a healthy eye prepared in advance. And a first specification unit that stores standard data and specifies a portion different from the first standard data in the data acquired by the data acquisition unit, and the display processing unit is specified by the first identification unit. The part of the blood flow graph corresponding to the part is displayed in a different manner from the other parts.

  A sixth aspect of the embodiment is the ophthalmologic imaging apparatus according to any one of the first to fourth aspects, wherein the storage unit is a second standard data of fundus blood flow dynamics in a patient's eye created in advance. And a second specifying unit that stores standard data and specifies a portion of the data acquired by the data acquiring unit that matches the second standard data, and the display processing unit is specified by the second identifying unit. The part of the blood flow graph corresponding to the part is displayed in a different manner from the other parts.

  A seventh aspect of the embodiment is the ophthalmologic imaging apparatus of any of the first to sixth aspects, wherein in the OCT blood flow measurement, the data acquisition unit intersects a blood vessel at a preset measurement position. The first cross section is repeatedly scanned to collect the first data, and one or more second cross sections crossing the blood vessel are scanned in the vicinity of the measurement position to collect the second data, and the second data is collected based on the second data. An inclination angle of the blood vessel at the measurement position is calculated, and based on the calculated inclination angle and the first data, blood flow data representing a time-series change of blood flow in the blood vessel passing through the first cross section The display processing unit displays the blood flow graph based on the blood flow data.

  An eighth aspect of the embodiment is the ophthalmologic imaging apparatus according to any one of the first to seventh aspects, wherein the data acquisition unit acquires data by applying OCT angiography to the fundus, and the display The processing unit displays a blood vessel-emphasized image based on the data acquired by OCT angiography.

  A ninth aspect of the embodiment is a memory for storing standard data of fundus blood flow dynamics prepared in advance and data acquired by applying optical coherence tomography (OCT) blood flow measurement to the fundus of an eye to be examined Unit and a display processing unit for displaying information on a display unit, the display processing unit representing a time-series change of blood flow in the blood vessel of the fundus based on the data acquired by the OCT blood flow measurement It is an ophthalmologic information processing apparatus which displays a blood flow graph and displays standard information based on the standard data in parallel with the blood flow graph.

  According to the embodiment, it is possible to preferably compare the fundus blood flow data of the eye to be examined obtained by the OCT blood flow measurement with the standard data.

It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an exemplary embodiment. It is a schematic diagram for explaining an example of the processing which the ophthalmology photographing instrument concerning an exemplary embodiment performs. It is a flowchart showing an example of operation | movement of the ophthalmologic imaging device which concerns on exemplary embodiment. It is a schematic diagram for explaining an example of the processing which the ophthalmology photographing instrument concerning an exemplary embodiment performs. It is a schematic diagram for explaining an example of the processing which the ophthalmology photographing instrument concerning an exemplary embodiment performs. It is a flowchart showing an example of operation | movement of the ophthalmologic imaging device which concerns on exemplary embodiment. It is a schematic diagram for explaining an example of the processing which the ophthalmology photographing instrument concerning an exemplary embodiment performs. It is a schematic diagram for explaining an example of the processing which the ophthalmology photographing instrument concerning an exemplary embodiment performs. It is a schematic diagram showing an example of the composition of the ophthalmologic information processing device concerning an exemplary embodiment.

  Exemplary embodiments of the invention will be described with reference to the drawings. In addition, it is possible to combine any known technique including the disclosure of the documents cited in this specification into the embodiment.

  The ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment have a function of displaying various information based on data acquired by applying OCT to the fundus of an eye to be examined. The ophthalmologic imaging apparatus according to the embodiment applies OCT blood flow measurement to the fundus of a subject's eye to acquire data, and executes display of various information based on the data. On the other hand, in the ophthalmologic information processing apparatus according to the embodiment, for example, the separately provided OCT apparatus receives data acquired by applying OCT blood flow measurement to the fundus of the eye to be examined, and displays various information based on this data Run. In particular, in the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment, the user compares the difference between the standard data of the fundus blood flow dynamics created in advance and the data of the subject eye obtained by the OCT blood flow measurement. Display information for grasping.

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

  The types of fundus oculi OCT data are not limited to these. Embodiments can also process various information associated with fundus OCT data. Examples of such information include subject identification information, eye identification information, identification information indicating whether the eye to be examined is a left eye or a right eye, shooting date, shooting conditions, and the like.

  An ophthalmologic photographing 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. The ophthalmologic imaging apparatus according to the embodiment further includes an optical system, a drive system, a control system, and a data processing system for performing the OCT.

  The ophthalmologic imaging apparatus according to the embodiment is configured to be able to execute, for example, Fourier domain OCT. Fourier domain OCT includes spectral domain OCT and swept source OCT. Spectral domain OCT is a method of constructing an image by acquiring the spectrum of interference light by space division using a wide band low coherence light source and a spectroscope, and Fourier transforming it. Swept-source OCT uses a wavelength-swept light source (wavelength variable light source) and a photodetector (such as a balanced photodiode) to acquire the spectrum of interference light by time division, and constructs an image by Fourier transforming it. Method. The method of OCT is not limited to Fourier domain OCT, and may be time domain OCT or amphas OCT.

  The ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment may include a modality (for example, a modality other than OCT) for imaging the eye and / or another part. As typical examples, there are a fundus camera, a scanning laser ophthalmoscope (SLO), a slit lamp microscope, a microscope for ophthalmologic surgery, and the like. In addition, the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment may include a configuration for measuring the characteristics of the eye and / or another part, and a configuration for performing an examination.

  The data processing function (calculation function, image processing function, control function, etc.) in the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment includes, for example, hardware such as a processor or storage device, an arithmetic program It is realized by the cooperation of software such as a program. In addition, a part of hardware may be provided in an external apparatus capable of communicating with the ophthalmologic information processing apparatus or the ophthalmologic imaging apparatus according to the embodiment. In addition, at least part of the software may be stored in advance in the ophthalmic information processing apparatus or the ophthalmic imaging apparatus according to the embodiment, and / or may be stored in advance in an external apparatus.

<Ophthalmic imaging device>
<Constitution>
An ophthalmologic imaging apparatus according to an exemplary embodiment will be described. An exemplary configuration of the ophthalmologic imaging apparatus of the present embodiment is shown in FIG. The ophthalmologic imaging apparatus 1 can collect data of the fundus using OCT, generate a fundus morphology image and fundus blood flow data based on the collected data, and can display various information based on these.

  Here, the fundus morphology image is an image expressing the morphology of the fundus. In the present embodiment, the fundus oculi shape image is an image represented in a mode in which at least a fundus blood vessel (retina blood vessel, choroidal blood vessel, etc.) can be visually identified. Examples of fundus morphology images include B-scan images, C-scan images, projection images, shadowgrams, phase images, and blood vessel-emphasized images. The fundus blood flow data is data representing a blood flow state (blood flow dynamics) in the fundus blood vessel. Examples of fundus blood flow data include blood flow direction, blood flow velocity, time-series change in blood flow velocity, blood flow, blood flow per unit time, time-sequential change in blood flow per unit time, whole blood flow, etc. .

  In the present embodiment, both morphological image and blood flow data are 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 (for OCT blood flow measurement) for acquiring blood flow data may be separately performed. . In addition, an OCT scan may be performed to acquire data other than these. For example, OCT angiography can be performed.

  A part of data used to display information may be acquired by another device. For example, one of the fundus morphology image and the fundus blood flow data may be acquired by another device. Alternatively, other devices may perform OCT angiography to obtain vessel-weighted images. 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 oculi shape image, blood flow information, and a blood vessel emphasis image on the display device 2. In particular, the ophthalmologic imaging apparatus 1 can display information based on blood flow information of the fundus of the eye to be examined and standard data of blood flow dynamics. For example, the ophthalmologic imaging apparatus 1 can display a graph (blood flow graph) representing the blood flow state of the fundus of the subject's eye and the information (standard information) based on the standard data side by side.

  The standard information may be, for example, a graph (standard blood flow graph) in the same manner as the blood flow graph. Also, the standard information may be statistical values based on standard data. This statistical value may be included in standard data or may be a value obtained by statistically processing standard data.

  The display device 2 may be part of the ophthalmologic imaging apparatus 1 or may be an external apparatus connected to the ophthalmologic imaging apparatus 1. Further, the ophthalmologic imaging 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, a data acquisition unit 30, an operation unit 50, and a front image acquisition unit 60. Control unit 10 includes a scan control unit 11, a partial data identification unit 12, and a display control unit 13. The data acquisition unit 30 includes an OCT scanner 31, an image forming unit 32, and a blood flow data generation unit 33.

<Control unit 10>
The control unit 10 controls each unit of the ophthalmologic imaging apparatus 1. The control unit 10 includes a processor. The “processor” is, for example, a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (for example, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD)). Or circuit such as FPGA (Field Programmable Gate Array). The control unit 10 can realize the function according to the embodiment by, for example, reading and executing a program stored in a storage circuit or a storage device (storage unit 20, external device or the like).

  In addition, the control unit 10 may include a communication device for transmitting and receiving data via a communication line such as a local area network (LAN), the Internet, and a private line.

<Scan control unit 11>
The scan control unit 11 controls the OCT scanner 31. For example, the scan control unit 11 controls the light source, controls the optical scanner, changes the optical path length of the measurement light and / or the reference light, adjusts the polarization, adjusts the light amount, adjusts the focus, changes the fixation position, etc. Control the various elements involved. Some examples of processing that can be executed by the scan control unit 11 will be described later.

<Partial data identification unit 12>
The partial data specification unit 12 compares blood flow data (or blood flow information based on it) of the fundus of the subject eye with standard data (or standard information based on it), and this blood flow data (or this blood) Identify the portion of interest in

  In a typical example, standard data of fundus hemodynamics in healthy eyes are used. In this case, the partial data specifying unit 12 can specify a portion different from the standard data (or the standard information based thereon) in the blood flow data of the fundus of the eye to be examined as a target portion.

  The portion of interest in this case corresponds to the portion of the blood flow data of the fundus of the subject's eye that deviates from the fundus blood flow dynamics of a healthy eye. In other words, an abnormal part (for example, a part presumed to be a sign or an influence of a disease) is identified in the blood flow data of the fundus of the subject eye.

  In addition, two or more standard data regarding a healthy eye can be provided. For example, it is possible to provide two or more standard data corresponding to items such as gender, age group, physical size (height, weight, body mass (BMI), etc.), medical history and the like.

  In another typical example, standard data of fundus hemodynamics in the affected eye are used. This standard data may be for a particular disease (eg, glaucoma, age-related macular degeneration, retinal artery occlusion, retinal vein occlusion, diabetic retinopathy, etc.). Also, for a single disease, it is possible to provide two or more standard data corresponding to the severity (e.g., initial, mild, moderate, severe).

  When standard data on an affected eye is used, the partial data identification unit 12 identifies a portion of blood flow data of the fundus of the subject's eye that matches the standard data (or standard information based thereon) as a portion of interest.

  The portion of interest in this case corresponds to a portion of blood flow data of the fundus of the subject's eye that matches (or is similar to) the fundus blood flow dynamics of the affected eye. In other words, an abnormal part (for example, a part presumed to be a sign or an influence of a specific disease) is identified in the blood flow data of the fundus of the subject eye.

  A specific example of such processing performed by the partial data identification unit 12 will be described later.

<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 the data stored in the storage unit 20.

  The display control unit 13 can perform processing (generation, processing, synthesis, and the like) on information displayed on the display device 2. Such processing may be executed by linking the display control unit 13 with other elements (other elements of the control unit 10, the data acquisition unit 30, etc.).

<Storage unit 20>
The storage unit 20 stores various data. In the present example, the standard data 21 and the OCT data 22 are stored in the storage unit 20. Note that at least a portion of the standard data 21 and / or at least a portion of the OCT data 22 may be stored in a storage device provided outside and provided to the ophthalmologic imaging apparatus 1 in response to a request. The storage unit 20 includes, for example, a storage device such as a hard disk drive and a semiconductor memory.

<Standard data 21>
The standard data 21 is standard data for any parameter representing fundus blood flow dynamics. This parameter may be any parameter obtained by processing data obtained by OCT blood flow measurement. Examples thereof include 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, whole blood flow, and the like.

  The creation of the standard data 21 is performed, for example, by applying OCT blood flow measurement to a large number of samples (that is, the fundus of a large number of subjects) to collect data and processing them statistically. . At this time, the sample may be, for example, a group of healthy eyes, a group of items of healthy eyes as described above, a group of diseased eyes, or a group of specific diseases as described above.

  As statistical values obtained by statistical processing for creating the standard data 21, for example, mean value, median value, mode value, quantile number, maximum value, minimum value, midpoint value, standard deviation, variance, standard There is an error etc.

  The standard data 21 is not limited to one created by such statistical processing. For example, the standard data 21 may include data on an eye to be examined that exhibits standard fundus hemodynamics. Typically, the standard data 21 is data acquired by applying OCT blood flow measurement to the fundus of the subject's eye diagnosed as a normal eye, or the fundus of the subject's eye diagnosed as a subject's eye Process any of the data obtained by applying OCT blood flow measurement, the data obtained by applying OCT blood flow measurement to the fundus of the subject's eye diagnosed to have a specific disease, or any of these data It may contain the data obtained by As another example, the standard data 21 may include data described in a paper or a book.

<OCT data 22>
The OCT data 22 includes any one or more of the fundus oculi OCT data (1) to (5) described above. Typically, the ophthalmologic imaging apparatus 1 generates morphological images and blood flow data from raw data collected by OCT scan (including at least OCT blood flow measurement) of the fundus, and stores OCT data 22 including these. Save to section 20. In other words, in the typical example, the above-mentioned fundus oculi OCT data (2) and (4) are included in the OCT data 22.

<Data acquisition unit 30>
The data acquisition unit 30 applies the OCT to the fundus of the subject's eye to acquire data (for example, at least a part of the OCT data 22 stored in the storage unit 20). As described above, the data acquisition unit 30 includes the OCT scanner 31, the image forming unit 32, and the blood flow data generation unit 33. The image forming unit 32 includes a processor that executes an image forming program. The blood flow data generation unit 33 includes a processor that executes a blood flow data generation program.

<OCT Scanner 31>
The OCT scanner 31 executes an OCT scan of the fundus under the control of the scan control unit 11. Thereby, fundus data (raw data) is collected. The OCT scanner 31 includes a configuration for performing optical interference measurement using, for example, spectral domain OCT or swept source OCT. As in the prior art, such an OCT scanner 31 includes an OCT optical system, a drive system, a data acquisition system (DAQ), a control system, and the like.

  The OCT optical system includes, for example, an interference optical system, an optical scanner, and a light detector. The interference optical system divides the light output from the light source into measurement light and reference light, projects this measurement light onto the fundus, superimposes the return light of the measurement light from the fundus on the reference light, and generates interference light Do. The optical scanner includes a galvano scanner or the like and deflects the 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 optical system.

  The drive system moves or operates elements included in the OCT optical system. The data acquisition system collects detection results sequentially obtained by the OCT optical system. The control system controls an OCT optical system, a drive system, a data acquisition system, and the like under the control of the scan control unit 11 (or other elements of the control unit 10).

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

  In OCT blood flow measurement, further, the OCT scanner 31 performs a scan for obtaining the inclination angle of the blood vessel of interest in the cross section of interest. This scan is performed, for example, on two cross sections crossing the blood vessel of interest. Here, two cross sections can be arranged in the vicinity of the cross section of interest.

  Note that one of the two cross sections for determining 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 described above can be used to calculate the inclination angle.

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

  The aspect of the scan for determining the inclination angle of the blood vessel of interest in the cross section of interest is not limited to these. For example, three or more cross sections can be scanned. Alternatively, a three-dimensional area including the cross section of interest can be scanned (three-dimensional scan). As another example, a cross section may be scanned that intersects the cross section of interest and along the blood vessel of interest. The OCT blood flow measurement will be described in detail in the description of the blood flow data generation unit 33.

  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). The raster scan is executed, for example, to scan each of a plurality of B cross sections (B scan planes) a predetermined number of times (for example, four times). In other words, this raster scan is executed to scan a plurality of B cross sections sequentially in a predetermined number of times or to scan according to a predetermined sequence. The three-dimensional data set acquired by the OCT scanner 31 is sent to the image forming unit 32.

  The aspect of the scan which can perform the OCT scanner 31 is not limited to the above-mentioned aspect. For example, the OCT scanner 31 can perform a line scan, a circle scan, a radial scan, a three-dimensional scan, and the like as an OCT scan for acquiring a morphological image.

<Image Forming Unit 32>
The image forming unit 32 forms an OCT image based on the data acquired 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 of the B cross sections based on the three-dimensional data set collected by the OCT scanner 31. The image forming process 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, cross-sectional images of the number corresponding to the number of times of scan repetition are assigned to each B cross-section. Furthermore, the image forming unit 32 can form volume data (voxel data) by subjecting the stack data to interpolation processing and the like. In this volume data, voxel groups in number corresponding to the number of times of scan repetition are allocated to positions corresponding to the respective B cross sections.

  The image forming unit 32 performs rendering on stack data or volume data to obtain a B-scan image (longitudinal cross-sectional image, axial cross-sectional image), C-scan image (horizontal cross-sectional image, horizontal cross-sectional image), projection image, shadow gram Etc can be formed.

  An image of an arbitrary cross section 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 a preset thickness in the thickness direction.

  The projection image is formed by projecting stack data or volume data in a predetermined direction (Z direction, depth direction, A scan direction). The shadowgram is formed by projecting a part 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, with the cornea side of the eye to be examined as a viewpoint is called a front image.

  The image forming unit 32 can execute various types of image processing in addition to rendering. For example, there are segmentation for obtaining a specific tissue or tissue boundary, and size analysis for obtaining the size (layer thickness, volume, etc.) of the tissue. When a specific layer (or a specific layer boundary) is determined by segmentation, it is possible to reconstruct a B-scan image or a front image so that the specific layer becomes flat. Such an image is called a flattened image.

  The image forming unit 32 can form a blood vessel emphasized image. The blood vessel-weighted image is an image in which an image area (blood vessel area) corresponding to a blood vessel is identified by analyzing OCT data, and the image aspect is enhanced by changing the expression mode of the blood vessel area. A plurality of OCT data obtained by repeatedly scanning substantially the same range of the eye to be examined is used to identify the vascular region.

  The blood vessel enhancement image represents, for example, the distribution of blood vessels (that is, the three-dimensional distribution of blood vessels) in the three-dimensional area of the OCT scanned fundus. There are several types of techniques for forming blood vessel-weighted images. The typical method for that is explained. In this process, a three-dimensional data set including a plurality of B scan images arranged in time series for each B cross section is used by repeatedly scanning each of the plurality of B cross sections of the eye to be examined. Fixation and tracking are methods for repeatedly scanning substantially the same B cross section.

  In the process of forming a blood vessel emphasis image, first, alignment of a plurality of B scan images is performed for each B cross section. This alignment is performed, for example, using a known image matching technique. As a typical example, extraction of a feature region in each B scan image and alignment of a plurality of B scan images by alignment of a plurality of extracted feature regions can be performed.

  Subsequently, processing is performed to specify an image area that is changing among the plurality of aligned B-scan images. This process includes, for example, a process of determining differences between different B-scan images. Each B scan image is luminance image data representing the form of the subject's eye, and an image area corresponding to a site other than a blood vessel is considered to be substantially unchanged. On the other hand, taking into account that the backscattering contributing to the interference signal changes randomly due to blood flow, an image area (for example, a pixel whose difference is not zero, or the like) changes among a plurality of registered B-scan images A pixel whose difference is equal to or more than a predetermined threshold can be estimated to be a blood vessel region.

  The image area identified in this manner is assigned information indicating that it is a blood vessel area. By performing the above-described process for a plurality of B cross sections, a three-dimensionally distributed blood vessel region is obtained. By rendering such a three-dimensional blood vessel-emphasized image, a frontal image representing the blood vessel distribution, an image of an arbitrary cross section, a shadowgram of an arbitrary range, and the like are generated.

  The process of forming a blood vessel weighted image is not limited to this. For example, it is possible to specify a blood vessel area by a conventional method using Doppler OCT, or to specify a blood vessel area using a conventional image processing method. In addition, it is possible to specify a blood vessel region for each part by using different methods depending on the part. For example, for the retina, a blood vessel region can be identified using the above-described typical technique or the Doppler OCT technique, and for the choroid, a blood vessel region can be identified using an image processing technique.

<Blood flow data generation unit 33>
The blood flow data generation unit 33 operates in OCT blood flow measurement. The blood flow data generation unit 33 is 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 a blood flow state in a blood vessel of interest is generated.

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

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

  As mentioned above, in a typical OCT blood flow measurement, two types of scans (an auxiliary scan and a main scan) are performed on the fundus. The auxiliary scan is performed to scan one or more cross sections different from the cross section of interest (a cross section near the cross section of interest) and collect second data. In a typical auxiliary scan, two or more cross sections crossing the blood vessel of interest are scanned with measurement light. The data acquired by the auxiliary scan is used to determine the inclination angle of the blood vessel of interest in the cross section of interest. On the other hand, the main scan is performed to repeatedly scan the cross section of interest crossing the blood vessel of interest with the measurement light to collect the first data. The cross section in which the auxiliary scan is performed is arranged in the vicinity of 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, for example, oriented orthogonal to the traveling direction of the blood vessel of interest. Further, the distance between the target cross section of the auxiliary scan and the cross section of interest (the distance between cross sections) is set in advance or set for each inspection. As an example of the latter, it is possible to set the distance between the cross sections based on the curvature of the target blood vessel at or near the cross section of interest and a predetermined factor such as inspection accuracy. Alternatively, the user may set a desired distance between cross sections.

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

  The image forming unit 32 may generate, for example, a cross-sectional image representing the form of the first auxiliary cross section based on data collected by the auxiliary scan on the two auxiliary cross sections set in the vicinity of the cross section of interest and And a cross-sectional image representing the form of the target cross-section. At this time, it is possible to improve the image quality by utilizing a technique such as averaging, or to select an optimal one from two or more cross sectional images of each auxiliary cross section.

  Furthermore, the image forming unit 32 forms a cross-sectional image group representing time-series change in the cross section of interest based on the data acquired by the main scan (repetitive scan) on the cross section of interest. This process is realized, for example, by forming a cross-sectional image from data collected at each scan iteration.

  The processing performed by the image forming unit 32 includes, for example, noise removal (noise reduction), filter processing, fast Fourier transform (FFT), and the like, as in the conventional OCT technology. The process of forming the cross-sectional image of the cross section of interest described here is the same as the form image forming process performed by the image forming unit 32.

  Furthermore, the image forming unit 32 forms a phase image representing a time-series change of the phase difference in the cross section of interest based on the data acquired by the main scan on the cross section of interest. The data used for this process is the same as the data used to form the cross sectional image (s) of the cross section of interest. 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-explanatory.

  An example of a method of forming a phase image will be described. In a typical example, the 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 for each pixel of the cross-sectional image of the cross section of interest based on the time-series change of the pixel value (brightness value) of that pixel. For any pixel, the image forming unit 32 considers the graph of the time-series change of the luminance value. The image forming unit 32 obtains a phase difference Δφ between two time points t1 and t2 (t2 = t1 + Δt) separated by a predetermined time interval Δt in this graph. Then, this phase difference Δφ is defined as a phase difference Δφ (t1) at time t1 (more generally, any time between two time points t1 and t2). By executing this process for each of a large number of preset points, a time-series change in phase difference in the pixel can be obtained.

  The phase image is a representation of the value of the phase difference at each point in time of each pixel as an image. This imaging process can be realized, for example, by representing the value of the phase difference with a display color or luminance. At this time, the color (for example, red) indicating that the phase has increased along the time series can be different from the color (for example, blue) indicating that the phase has decreased. Also, the magnitude of the phase change amount can be expressed by the density of the display color. By adopting such an expression method, it is possible to express the direction and size of blood flow by color and concentration. A phase image is formed by performing the above processing for each pixel.

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

  The blood flow data generation unit 33 can execute, for example, blood vessel region identification processing, inclination angle calculation processing, and blood flow data generation processing. 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 area specifying process, the blood flow data generation unit 33 specifies a blood vessel area in each cross-sectional image corresponding to the blood vessel of interest. Furthermore, the blood flow data generation unit 33 specifies a blood vessel region in the phase image corresponding to the cross section of interest. The identification of the blood vessel region is performed by analyzing the pixel value of each image (for example, threshold processing). 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 the registration between the cross sectional image and the phase image.

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

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

  The blood flow data generation unit 33 calculates the inclination of the blood vessel of interest in the cross section of interest based on the cross-sectional image of interest 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 one or more arbitrary number.

  The blood flow data generation unit 33 calculates the inclination of the blood vessel of interest in the cross section of interest based on the blood vessel regions V0, V11, and V12 and the distance between the cross sections. The cross-sectional distance may be a 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 target cross-sectional image B0 and the distance between the auxiliary cross-sectional image B12 and the target cross-sectional image B0 Good. The distance between the auxiliary cross sectional image B11 (or B12) and the cross sectional image B0 of interest is L.

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

  In a typical example, the blood flow data generation unit 33 can calculate the inclination A of the blood vessel of interest in the cross section of interest 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 generation unit 33 identifies feature points of the three blood vessel regions V0, V11 and V12, and connects these feature points. The feature points referred to here include the center position (axis line position), the center of gravity position, the top, and the like. Further, as a method of connecting these feature points, there are a method of connecting by line segments, a method of connecting by approximate curves (spline curve, Bezier curve, etc.), and the like.

  Furthermore, the blood flow data generation unit 33 calculates the inclination A based on the line connecting these feature points. When a line segment is used, the blood flow data generation unit 33 may, for example, form 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. The inclination A can be calculated on the basis of the inclination of the blood vessel area V0 and the inclination of the second line segment connecting the characteristic point of the blood vessel area 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 determined. Further, as an example in the case of connecting by an approximate curve, the inclination of the approximate curve at the intersection position of the approximate curve and the cross section of interest can be determined.

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

  Further, although only one value of the inclination A is obtained in the above example, the inclination may be obtained for each of two or more positions (or areas) in the blood vessel area V0. In this case, two or more obtained slope values can be separately used, or one value (for example, an average value) statistically obtained from the slope values can be used as the slope A.

  In the blood flow data generation process, the blood flow data generation unit 33 relates to the focused blood vessel based on the phase image formed based on the main scan (Doppler OCT) and the inclination angle obtained by the blood flow data generation unit 33. Generate blood flow data. As described above, in a typical example, blood flow data generation processing includes blood flow velocity calculation processing, blood vessel diameter calculation processing, and blood flow amount calculation processing.

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

  When blood flow velocity change data is obtained, the blood flow data generation unit 33 can calculate the statistical value of the blood flow velocity in the range of the time. The statistical values include mean value, standard deviation, variance, median value, maximum value, minimum value, maximum value, minimum value, and the like. It is also possible to create a histogram for blood flow velocity values.

  The blood flow data generation unit 33 can calculate the blood flow velocity using the method of Doppler OCT 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 rate of medium (blood flow velocity)
θ: angle (inclination angle) between the incident direction of the measurement light and the flow direction of the medium
λ: central wavelength of measurement light

  In a typical example, the refractive power n of the medium and the central wavelength λ of the measurement light are known, the Doppler shift Δf is obtained from the time-series change of the phase difference, and the tilt angle θ is tilt angle calculation processing or blood vessel angle distribution Obtained from The blood flow data generation unit 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 generation unit 33 calculates the diameter of the blood vessel of interest in the cross section of interest. 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, imaging of a region of the fundus including the position of the cross section of interest is performed in advance. The fundus imaging is performed by, for example, the front image acquisition unit 60. Alternatively, the front image of the fundus acquired and stored in the past may be read out. Alternatively, a blood vessel weighted image may be used.

  The blood flow data generation unit 33 determines 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 imaging angle of view (imaging magnification), working distance, and information on the eyeball optical system. Set the scale in the front image. This scale represents the length in real space. As a specific example, this scale corresponds to the interval between adjacent pixels and the scale in the real space (for example, the interval between pixels = 10 μm). In addition, it is also possible to calculate in advance the relationship between various values of the factor and the scale in the real space, and store information representing this relationship in a table format or a graph format. In this case, a scale corresponding to the above factor is 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 the scale and the pixels included in the blood vessel region. As a specific example, the blood flow data generation unit 33 can obtain the maximum value or the average value of the diameters in various directions of the blood vessel region. Alternatively, the blood flow data generation unit 33 can circularly approximate or elliptically approximate the contour of the blood vessel region, and obtain the diameter of the circle or ellipse. Since the area of the blood vessel region can be (substantially) determined if the blood vessel diameter is determined, the area may be calculated instead of determining the blood vessel diameter.

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

  In the blood flow rate calculation process, the blood flow data generation unit 33 calculates the flow rate of the blood flowing in the target blood vessel based on the calculation result of the blood flow velocity and the calculation result of the blood vessel diameter. An example of this process is described below.

  It is assumed that blood flow in the blood vessel is Hagen-Poiseuille flow. Also, the blood vessel diameter is w, and the maximum value of the blood flow velocity is Vm. In this case, the blood flow rate Q is expressed 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 processing and the maximum value Vm of the blood flow velocity obtained by the blood flow velocity calculation processing into the above-mentioned relational expression to obtain the blood flow volume. Q can be calculated.

<Operation unit 50>
The operation unit 50 is used by the user to input an instruction to the ophthalmologic imaging apparatus 1. The operation unit 50 may include a known operation device used for an ophthalmologic apparatus or a computer. For example, the operation unit 50 may include a mouse, a touch pad, a trackball, a keyboard, a pen tablet, an operation panel, a joystick, a button, a 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 an instruction or information on the touch panel.

Front Image Acquisition Unit 60
The front image acquisition unit 60 acquires a front image of the fundus. The process for acquiring a front image is optional. In the first example, the front image acquisition unit 60 may include a configuration for photographing the fundus. For example, the front image acquisition unit 60 may include an optical system of a fundus camera, an optical system of SLO, and the like.

  In the second example, the front image acquisition unit 60 may include a configuration for acquiring a front image of the fundus of the eye to be examined from an external device. For example, the front image acquisition unit 60 may include a communication device for transmitting and receiving data via a communication line such as a LAN, the Internet, or a dedicated line. In this case, the front image acquisition unit 60 can acquire, for example, a patient ID, a DICOM tag, or the like as a search query for the front image of the fundus of the subject eye stored in an electronic medical record system or an image archiving system.

  In the third example, the front image acquisition unit 60 may include a processor that forms a front image by OCT. The OCT front image includes a C-scan image, a projection image, a shadowgram, and the like.

<Operation>
An example of the operation of the ophthalmologic imaging apparatus 1 according to the present embodiment will be described. Hereinafter, in the first operation example, the case where the partial data identification unit 12 is not used will be described, and in the second operation example, the case where the partial data identification unit 12 is used will be described.

<First operation example>
An example of the operation of the ophthalmologic imaging apparatus 1 is shown in FIG. Here, preliminary processing such as input of patient ID, alignment of optical system with respect to eye to be examined, focus adjustment of optical system, OCT optical path length adjustment, adjustment of fixation position, setting of OCT scan range, etc. has already been performed. It shall be. Also, it is assumed that the standard data 21 is already stored in the storage unit 20.

(S1: Execute OCT blood flow measurement of the fundus)
The ophthalmologic imaging apparatus 1 performs OCT blood flow measurement on a target cross section of a target blood vessel of a fundus of a subject's eye. The OCT blood flow measurement is performed on each of the one or more cross sections of interest in each of the one or more blood vessels of interest. In addition, when there are a plurality of blood vessels passing through the cross section of interest, at least one of the blood vessels can be used as the blood vessel of interest. Conversely, the cross section of interest can also be set to cross multiple blood vessels of interest.

  In OCT blood flow measurement, the scan control unit 11 controls a light source and an optical scanner included in the OCT scanner 31. Under control of the scan control unit 11, the OCT scanner 31 repeatedly scans the first cross section crossing the blood vessel of interest at the measurement position (that is, the cross section of interest) set in advance, and collects the first data. The second data is acquired by scanning one or more auxiliary cross-sections crossing the blood vessel of interest in the vicinity of. The order of collecting the first data and collecting the second data is arbitrary.

(S2: form a morphological image)
The image forming unit 32 forms one or more morphological images (B-scan images) corresponding to the cross section of interest based on the first data acquired by repeatedly scanning the cross section of interest in step S1. Typically, the same number of morphological images can be formed as the number of scan repetitions. Thus, a time-series B-scan image corresponding to the cross section of interest is obtained. The number of morphological images may be smaller than the number of scan repetitions.

  Furthermore, the image forming unit 32 forms a morphological image (B-scan image) corresponding to each auxiliary cross section based on the second data acquired by scanning one or more auxiliary cross sections in step S2.

  Each morphological image formed in step S2 is stored in the storage unit 20 as the OCT data 22.

(S3: Find the inclination angle of the blood vessel of interest)
The blood flow data generation unit 33 obtains the inclination angle of the blood vessel of interest in the cross section of interest based on two or more of the plurality of morphological images formed in step S2. For this process, 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 a cross section of interest is used.

(S4: form a phase image)
The image forming unit 32 forms a phase image corresponding to the cross section of interest based on the first data acquired by repeatedly scanning the cross section of interest in step S1.

  The phase image formed in step S4 is stored in the storage unit 20 as the OCT data 22.

(S5: Obtain blood flow data)
The blood flow data generation unit 33 generates blood flow data of the blood vessel of interest passing through the cross section of interest based on the inclination angle of the blood vessel of interest acquired at step S3 and the phase image formed at step S4. This blood flow data includes, for example, data representing time-series changes in blood flow in the blood vessel of interest. As an example of such data, time-series changes in blood flow velocity in the measurement period of OCT blood flow measurement (typically, a period of one cardiac cycle or more) performed in step S1, or the measurement period There are time-series changes of blood flow volume per unit time in

  The blood flow data generated in step S5 is stored in the storage unit 20 as the OCT data 22. When considering a plurality of blood vessels of interest, blood flow data is obtained for each of the blood vessels of interest. Furthermore, for each of the plurality of blood vessels of interest, identification information (for example, position information of the blood vessel of interest) and corresponding blood flow data are associated with each other and stored in the storage unit 20.

(S6: Create blood flow graph)
The display control unit 13 creates a blood flow graph representing the fundus blood flow dynamics of the subject's eye based on the blood flow data generated in step S5. The blood flow graph represents the time-series change of the blood flow in the blood vessel of interest in the cross section of interest.

The blood flow graph creation process includes, for example, the following process.
(1) Blood flow data (for example, blood flow velocity or blood flow per unit time) generated in step S5, the horizontal axis (first coordinate axis) indicates time t, and the vertical axis (second coordinate axis) Process of plotting in a two-dimensional orthogonal coordinate system in which blood flow velocity (v) is shown (2) Process of connecting the plotted point groups with a line.

  Here, the values of the point group to be plotted (that is, the values on the vertical axis) are, for example, the values of a plurality of pixels corresponding to the blood vessel cross section of interest in the corresponding time phase (that is, the values on the horizontal axis) (that is, blood It may be a statistical value of the value corresponding to the size of the flow velocity etc. This statistical value may be, for example, an average value, an intermediate value, a mode value, a maximum value, a minimum value, or the like. Alternatively, the value of the vertical axis may be the value of a predetermined pixel (for example, a pixel located at the center, a pixel located at the center of gravity, etc.) in the blood vessel cross section of interest in the corresponding time phase.

  Further, the process of connecting the plotted point groups with a line includes a process of connecting points that are temporally adjacent to each other with a line. The line connecting adjacent points may be a straight line or a curved line. If the connecting line is a curve, it is possible to apply, for example, any approximate curve (for example, a spline curve, a Bezier curve, etc.) having the plotted point group as a control point. Also, Lagrange interpolation or the like may be applied to interpolate a point group.

(S7: Create standard information)
The display control unit 13 creates standard information based on the standard data 21 stored in the storage unit 20.

  For example, when the standard data 21 includes data representing a time-series change of a predetermined parameter (for example, blood flow velocity or blood flow per unit time), the display control unit 13 performs blood flow in the same manner as step S6. A graph (standard blood flow graph) can be created. Alternatively, the display control unit 13 can obtain statistical values of predetermined parameters in each time phase based on the standard data 21. This statistical value may be, for example, an average value, an intermediate value, a mode value, a maximum value, a minimum value, or the like.

  If the standard data 21 already contains standard information, there is no need to execute step S7.

  As an optional process, the display control unit 13 can execute a process of matching the scale of the blood flow graph with the scale of the standard information. For example, in order to cancel the difference between the subject's heart rate and the standard heart rate, the display control unit 13 may adjust the time scale between the blood flow graph and the standard blood flow graph. It is possible.

  In addition, although this is also an optional process, the display control unit 13 can execute a process of matching the timing of the blood flow graph with the timing of the standard information. For example, the display control unit 13 adjusts both timings (that is, relatively move both in the time axis direction) so that the peak position of the blood flow graph and the peak position of the standard blood flow graph are matched. Is possible.

(S8: Display blood flow graph and standard information)
The display control unit 13 causes the display device 2 to display the blood flow graph of the fundus of the subject's eye created in step S6 and the standard information created in step S7 on the display device 2.

  An example of the information displayed in step S8 is shown in FIG. 4A. In this example, a blood flow graph 140 representing a time-series change in blood flow in a blood vessel of interest and a standard blood flow graph 160 representing a time-sequential change in standard blood flow are displayed.

  Each of the blood flow graph 140 and the standard blood flow graph 160 in this example is represented by a two-dimensional orthogonal coordinate system in which the horizontal axis indicates time t and the vertical axis indicates blood flow velocity (v). Similarly, even when other parameters such as blood flow rate per unit time are applied, it is possible to display a graph in which the horizontal axis indicates time and the vertical axis indicates the parameter.

  In this example, the time axis t of the blood flow graph 140 and the time axis t of the standard blood flow graph 160 are synchronized. That is, the blood flow graph 140 and the standard blood flow graph 160 are displayed so that the user can recognize the correspondence between the time phase of the blood flow graph 140 and the time phase of the standard blood flow graph 160.

  Further, in this example, the blood flow graph 140 and the standard blood flow graph 160 are displayed so as to satisfy the following conditions: (1) Scale of time axis t of the blood flow graph 140 and the standard blood flow graph 160 The scale of the time axis t of is the same; (2) the period represented by the time axis t of the blood flow graph 140 and the period represented by the time axis t of the standard blood flow graph 160 are equal; (3) same time phase (time) Are arranged at corresponding positions (corresponding positions in the vertical direction).

In general, it is not necessary that the scale of the time axis t of the blood flow graph 140 and the scale of the time axis t of the standard blood flow graph 160 be equal. For example, by such as setting one of the scale of the time axis t ₁ to an integer multiple of the scale of the other of the time axis t _2, it is possible to clarify the mutual relationship.

  Also, in general, the period represented by the time axis t of the blood flow graph 140 and the period represented by the time axis t of the standard blood flow graph 160 do not have to be equal. For example, one period may be part of the other period, or part of one period may be equal to part of the other period.

  The display control unit 13 can overlap and display the blood flow graph 140 and the standard blood flow graph 160 on the same time axis (same coordinate system). At this time, the display color of the blood flow graph 140 and the display color of the standard blood flow graph 160 can be different.

  The display processing unit 13 can display the fundus blood flow information and the biological information as a moving image so that the respective time phases are synchronized. In the present example, the display control unit 13 can synchronously move the blood flow graph 140 and the standard blood flow graph 160 along the respective time axes t.

  Another example of the information displayed in step S8 is shown in FIG. 4B. In this example, a blood flow graph 140 representing a time-series change in blood flow in a blood vessel of interest and a statistical value as standard information are displayed. In addition to this, a standard blood flow graph 160 similar to that of FIG. 4A may be displayed in parallel with the blood flow graph 140.

  The code | symbol 161 is a line which shows the average value of the blood flow velocity calculated from the standard data 21. FIG. In this case, it is possible to further display a line 141 indicating the average value of the blood flow velocity calculated from the blood flow graph 140 (or blood flow data). Thereby, the user can easily compare the average value of both blood flow velocities.

  The code | symbol 161 is a line which shows the maximum value of the blood flow velocity calculated | required from the standard data 21. FIG. The user can easily compare the maximum values of both blood flow velocities by comparing the maximum value line 161 with the blood flow graph 140.

  The display control unit 13 can display a morphological image or a phase image of the cross section of interest together with such a blood flow graph and standard information. In addition to the OCT blood flow measurement, when OCT angiography is performed, the display control unit 13 can cause the display device 2 to display a blood vessel emphasized image acquired by the OCT angiography.

<Second operation example>
Another example of the operation of the ophthalmologic imaging apparatus 1 is shown in FIG. Here, preliminary processing such as input of patient ID, alignment of optical system with respect to eye to be examined, focus adjustment of optical system, OCT optical path length adjustment, adjustment of fixation position, setting of OCT scan range, etc. has already been performed. It shall be. Also, it is assumed that the standard data 21 is already stored in the storage unit 20. In the present example, the partial data identification unit 12 is used.

(S11 to S17)
Steps S11 to S17 are respectively performed in the same manner as steps S1 to S7 of the first operation example.

(S18: Identify the notable part of the blood flow graph)
The partial data specifying unit 12 generates, for example, the blood flow data generated in step S15 and / or the blood flow graph generated in step S16, the standard data 21 stored in the storage unit 20, and / or the step S17. The target portion of the blood flow graph created in step S16 is identified based on the obtained standard information.

  For example, when the standard data 21 of fundus blood flow dynamics in a healthy eye is applied, the partial data specification unit 12 uses this standard in the blood flow data generated in step S15 and / or the blood flow graph generated in step S16. The portion different from the data 21 is identified. This identification process is performed, for example, by comparing the blood flow graph with the standard blood flow graph.

  In a typical example, the partial data identification unit 12 executes the following series of processing. First, the partial data identification unit 12 obtains a feature amount (for example, an arbitrary statistical value of the blood flow velocity, a period of the blood flow graph, an amplitude of the blood flow graph, and the like) from the blood flow graph. Similarly, the partial data identification unit 12 obtains the same feature amount from the standard blood flow graph. These processes are performed, for example, by dividing the time axis into a plurality of sections. Furthermore, the partial data identification unit 12 identifies the portion of the blood flow graph that does not match the feature amount of the standard blood flow graph by comparing the feature amount of the blood flow graph with the feature amount of the standard blood flow graph. The identified part is treated as a notable part.

  Another example will be described. When the standard data 21 of the fundus blood flow dynamics in the diseased eye (for example, an eye having a specific disease) is applied, the partial data specification unit 12 generates the blood flow data generated in step S15 and / or step S16. In the blood flow graph thus determined, a portion that matches this standard data 21 is identified. This particular process can also be performed in the same way.

(S19: Process the attention part)
The display control unit 13 processes the target portion identified in step S18. This processing includes, for example, processing of changing the form (for example, shape, color, form of line, etc.) of the part of interest and / or processing of adding an object (for example, image, text, etc.) indicating the part of interest including.

(S20: Display the blood flow graph in which the part of interest has been processed)
The display control unit 13 causes the display device 2 to display the blood flow graph in which the target portion is processed in step S19. At this time, as in step S8 of the first operation example, it is possible to display standard information, to display a morphological image or a phase image of a cross section of interest, or to display a blood vessel-emphasized image.

  An example of the blood flow graph displayed in step S20 is shown in FIG. 6A. In the blood flow graph 140 of this example, the portion of interest specified in step S18 is represented by a thicker line than the other portions. Specifically, the six notable parts of the blood flow graph 140 are represented by thick lines 151 to 156. Thereby, the user can easily grasp the portion of interest of the blood flow graph 140 (for example, the portion presumed to be a symptom or an effect of a disease).

  Another example of the blood flow graph displayed in step S20 is shown in FIG. 6B. In the blood flow graph 140 of the present example, a circular image indicating the portion of interest identified in step S18 is added. Specifically, the six notable parts of the blood flow graph 140 are surrounded by circular images 171 to 176. Thereby, the user can easily grasp the portion of interest of the blood flow graph 140 (for example, the portion presumed to be a symptom or an effect of a disease).

  Furthermore, in the example shown in FIG. 6B, the explanation of the portion of interest is added to the blood flow graph 140. For example, a balloon 182 indicating that the peak value of the blood flow velocity is low is displayed for the target portion surrounded by the circular image 172. Although illustration is omitted, the same balloon can be displayed also on the target portion surrounded by the other circular images 171 and 173 to 176. In addition, for example, when the user specifies a desired target portion using the operation unit 50, the display control unit 13 can be configured to display a balloon corresponding to the specified target portion.

<Ophthalmic information processing device>
An ophthalmologic information processing apparatus according to an exemplary embodiment will be described. A configuration example of the ophthalmologic information processing apparatus of the present embodiment is shown in FIG. The ophthalmologic information processing apparatus 200 stores data of the fundus (including blood flow data) acquired using OCT blood flow measurement, and displays various information based on the stored data. Furthermore, the ophthalmologic information processing apparatus 200 may be configured to store data acquired using OCT angiography and to display information based on the data.

  The ophthalmologic information processing apparatus 200 can display various information such as, for example, blood flow information, a fundus oculi shape image, 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 200, or may be an external apparatus connected to the ophthalmologic information processing apparatus 200. The ophthalmologic information processing apparatus 200 can send various information to a computer, a storage device, an ophthalmologic apparatus, and the like.

  The ophthalmologic information processing apparatus 200 includes a control unit 210, a storage unit 220, a data processing unit 230, a data input unit 240, and an operation unit 250. Control unit 210 includes a partial data identification unit 212 and a display control unit 213. The storage unit 220 stores standard data 221 and OCT data 222.

  Each element of the ophthalmologic information processing apparatus 200 has, for example, the same configuration and function as the corresponding element included in the ophthalmologic imaging apparatus 1 described above. That is, control unit 210 has the same configuration and function as control unit 10, partial data specification unit 212 has the same configuration and function as partial data specification unit 12, and display control unit 213 includes display control unit 13. The storage unit 220 has the same configuration and function as the storage unit 20, and the operation unit 250 has the same configuration and function as the operation unit 50.

  The standard data 221 and the OCT data 222 may be the same as the standard data 21 and the OCT data 22 stored in the ophthalmologic imaging apparatus 1 described above.

  The data processing unit 230 executes various data processing. The data processing unit 230 may have the same configuration and function as the image forming unit 32. For example, when the OCT data 222 includes at least one of the OCT data (1), (3), and (5) described above, the data processing unit 230 executes the same process as the image forming unit 32 to obtain an OCT image. (Morphological image, phase image, etc.) can be formed.

  The data processing unit 230 may have the same configuration and function as the blood flow data generation unit 33. For example, when the OCT data 222 includes at least one of the OCT data (1) and (5) described above, the data processing unit 230 performs the same process as the blood flow data generation unit 33 to perform blood flow data ( Blood flow rate, blood flow, etc.) can be generated.

  The data input unit 240 inputs the standard data 221 to the ophthalmologic information processing apparatus 200 from the outside. Furthermore, the data input unit 240 externally inputs the OCT data 222 and / or the data that is the source of the OCT data 222 into the ophthalmic information processing apparatus 200. The data input unit 240 may include, for example, a communication interface for performing data communication with an external device, a device that reads data from a recording medium, and the like.

  The display control unit 213 can display the same information as the information displayed by the display control unit 13 of the ophthalmologic photographing apparatus 1 described above in the same manner. For example, the display control unit 213 can execute control for causing the display device 2 to display the same information as at least one of FIGS. 4A, 4B, 6A, and 6B.

<Operation / Effect>
The operation and effects of the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the above-described exemplary embodiment will be described.

  An ophthalmologic photographing apparatus (1) according to an embodiment includes a storage unit (20), a data acquisition unit (30), and a display processing unit (such as a display control unit 13). The storage unit stores standard data (21) of fundus blood flow dynamics created in advance. The data acquisition unit applies at least OCT blood flow measurement to the fundus of the subject's eye to acquire data (OCT data 22). The display processing unit causes the display unit (display device 2) to display information.

  Specifically, the display processing unit displays a blood flow graph representing a time-series change of the blood flow in the blood vessels of the fundus based on the data acquired by the data acquisition unit. Furthermore, the display processing unit displays standard information based on the standard data stored in the storage unit in parallel with the blood flow graph.

  An ophthalmologic information processing apparatus (200) according to an embodiment includes a storage unit (220) and a display processing unit (such as a display control unit 213). The storage unit includes standard data (221) of fundus blood flow dynamics created in advance and data (OCT data 222) acquired by applying optical coherence tomography (OCT) blood flow measurement to the fundus of an eye to be examined. Remember. The display processing unit causes the display unit (display device 2) to display information.

  Specifically, the display processing unit displays a blood flow graph representing a time-series change of the blood flow in the blood vessel of the fundus based on the data acquired by the OCT blood flow measurement. Furthermore, the display processing unit displays standard information based on the standard data in parallel with the blood flow graph.

  According to such an embodiment, the user can easily compare visually the fundus blood flow data of the eye to be examined obtained by the OCT blood flow measurement with the standard information based on the standard data. .

  In the embodiment, the display processing unit may be configured to display a standard blood flow graph based on standard data as the standard information.

  According to such a configuration, the user can compare both the fundus blood flow data of the eye to be examined obtained by the OCT blood flow measurement and the standard data in a graph.

  In embodiments, the blood flow graph may be configured such that the first coordinate axis represents time and the second coordinate axis is represented by a two-dimensional orthogonal coordinate system indicating blood flow velocity or blood flow volume per unit time. .

  According to such a configuration, since both the blood flow graph and the standard blood flow graph can be displayed in the same mode, it is possible to more easily compare the fundus blood flow data of the subject eye with the standard data. become.

  In the embodiment, the display processing unit may be configured to display a statistical value based on standard data as the standard information.

  According to such a configuration, it is possible to observe the blood flow graph of the subject's eye while referring to the statistical value based on the standard data.

  In the embodiment, the storage unit may store first standard data which is standard data of fundus blood flow dynamics in a healthy eye prepared in advance. In this case, the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment specify a first identification unit (partial data identification unit) that identifies a portion (attention portion) different from the first standard data in the data acquired by the data acquisition unit. 12, 212) may be included. Furthermore, the display processing unit may be configured to display a portion of the blood flow graph corresponding to the target portion identified by the first identification portion in a manner different from other portions.

  Further, in the embodiment, the storage unit may store second standard data which is standard data of fundus blood flow dynamics in a diseased eye prepared in advance. In this case, the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment specify a second identification unit (partial data identification unit) that identifies a portion (attention portion) that matches the second standard data in the data acquired by the data acquisition unit. 12, 212) may be included. Furthermore, the display processing unit may be configured to display a portion of the blood flow graph corresponding to the target portion identified by the second identification unit in a manner different from that of the other portions.

  According to such a configuration, the user can easily grasp an attention portion (for example, a portion presumed to be a symptom or an influence of a disease) of the blood flow graph of the eye to be examined.

  In the ophthalmologic imaging apparatus according to the embodiment, the data acquisition unit (30) may be configured to execute the following series of processing in OCT blood flow measurement: the blood vessel crosses a blood vessel at a preset measurement position Repeatedly scanning one cross section to collect first data; scanning one or more second cross sections crossing the blood vessel in the vicinity of the measurement position to collect second data; measurement position based on the second data Calculating an inclination angle of the blood vessel in the; and based on the calculated inclination angle and the first data, acquiring blood flow data representing a time-series change of blood flow in the blood vessel passing through the first cross section.

  According to such a configuration, OCT blood flow measurement can be suitably performed to generate blood flow data, and furthermore, a blood flow graph can be displayed based on the blood flow data.

  In the ophthalmologic imaging apparatus according to the embodiment, the data acquiring unit (30) may be configured to acquire data by applying OCT angiography to the fundus of the eye to be examined. Furthermore, the display processing unit (13) may be configured to display a blood vessel emphasized image based on data acquired by OCT angiography.

  In the ophthalmologic information processing apparatus according to the embodiment, the storage unit (220) may be configured to store data acquired by applying OCT angiography to the fundus of the subject's eye. Furthermore, the display processing unit (213) may be configured to display a blood vessel emphasized image based on data acquired by OCT angiography.

  According to such a configuration, the user can grasp the distribution of the fundus blood vessels in addition to the fundus blood flow dynamics of the eye to be examined.

  The actions and effects of the embodiments are not limited to these, but the actions and effects provided by the respective items described in the embodiments, and the actions and effects provided by the combination of a plurality of matters should also be considered. In addition, in order to obtain desired actions and / or effects, or for other purposes, it is possible to arbitrarily combine any of the above-described embodiments, other embodiments, known techniques, and the like.

  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 present invention can be appropriately applied.

DESCRIPTION OF SYMBOLS 1 ophthalmologic imaging apparatus 2 display device 10 control part 11 scan control part 12 partial data identification part 13 display control part 20 storage part 21 standard data 22 OCT data 30 data acquisition part 31 OCT scanner 32 image formation part 33 blood flow data generation part 50 Operation unit 140 Blood flow graph 160 Standard blood flow graph 200 Ophthalmic information processing apparatus 210 Control unit 212 Partial data specification unit 213 Display control unit 220 Storage unit 221 Standard data 222 OCT data 230 Data processing unit 240 Data input unit 250 Operation unit

Claims (9)

A storage unit for storing standard data of fundus blood flow dynamics created in advance;
A data acquisition unit that acquires data by applying optical coherence tomography (OCT) blood flow measurement to the fundus of an eye to be examined;
A display processing unit for displaying information on the display means;
The display processing unit
Based on the data acquired by the data acquisition unit, a blood flow graph showing time-series changes in blood flow in the blood vessels of the fundus is displayed;
Displaying standard information based on the standard data in parallel with the blood flow graph;
Ophthalmic imaging device. The display processing unit displays a standard blood flow graph based on the standard data as the standard information.
An ophthalmologic photographing apparatus according to claim 1. Each of the blood flow graph and the standard blood flow graph is represented by a two-dimensional orthogonal coordinate system in which the first coordinate axis indicates time and the second coordinate axis indicates blood flow velocity or blood flow volume per unit time.
An ophthalmologic photographing apparatus according to claim 2. The display processing unit displays a statistical value based on the standard data as the standard information.
The ophthalmologic imaging device according to any one of claims 1 to 3. The storage unit stores first standard data which is standard data of fundus blood flow dynamics in a normal eye prepared in advance;
And a first specification unit that specifies a portion different from the first standard data in the data acquired by the data acquisition unit.
The display processing unit displays a part of the blood flow graph corresponding to the part specified by the first specifying part in a manner different from other parts.
The ophthalmologic imaging device according to any one of claims 1 to 4. The storage unit stores second standard data which is standard data of fundus blood flow dynamics in a patient's eye which has been prepared in advance;
And a second identification unit that identifies a portion of the data acquired by the data acquisition unit that matches the second standard data,
The display processing unit displays the part of the blood flow graph corresponding to the part specified by the second specifying part in a manner different from other parts.
The ophthalmologic imaging device according to any one of claims 1 to 4. In OCT blood flow measurement, the data acquisition unit
Collecting a first data by repeatedly scanning a first cross section crossing a blood vessel at a preset measurement position;
Second data is acquired by scanning one or more second cross sections crossing the blood vessel in the vicinity of the measurement position;
Calculating an inclination angle of the blood vessel at the measurement position based on the second data;
Blood flow data representing a time-series change in blood flow in a blood vessel passing through the first cross section is acquired based on the calculated inclination angle and the first data,
The display processing unit displays the blood flow graph based on the blood flow data.
The ophthalmologic imaging device according to any one of claims 1 to 6. The data acquisition unit applies OCT angiography to the fundus to acquire data.
The display processing unit displays a blood vessel emphasized image based on the data acquired by OCT angiography.
The ophthalmologic imaging device according to any one of claims 1 to 7. A storage unit configured to store standard data of fundus blood flow dynamics created in advance and data acquired by applying optical coherence tomography (OCT) blood flow measurement to the fundus of an eye to be examined;
A display processing unit for displaying information on the display means;
The display processing unit
Based on the data acquired by the OCT blood flow measurement, a blood flow graph representing a time-series change in blood flow in the blood vessel of the fundus is displayed.
Displaying standard information based on the standard data in parallel with the blood flow graph;
Ophthalmic information processor.

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