JP6888643B2 - OCT analysis processing device and OCT data processing program - Google Patents

Description

The present disclosure relates to optical coherence tomography to obtain OCT data of a subject.

An optical coherence tomography (OCT) is known as a device for photographing a tomographic image of a subject.

In an optical tomography interferometer, a Fourier domain OCT is known that obtains a tomographic image of a test object by Fourier analysis of spectral information acquired by a light receiving element (see Patent Document 1). As the Fourier domain OCT, SD-OCT having a spectroscopic optical system in the light receiving system and SS-OCT having a variable wavelength light source in the light projecting system are known.

By the way, the tomographic image obtained by the interference optical system based on the Fourier domain OCT has the highest sensitivity (interference sensitivity) at the depth position (zero delay position) where the optical path lengths of the measurement light and the reference light match. The sensitivity decreases as the distance from the zero delay position increases. As a result, a high-sensitivity and high-resolution image can be obtained in the portion near the zero delay position, but the sensitivity and resolution of the image are lowered in the portion far from the zero delay position.

Patent Documents 1 to 3 describe a tomographic image (normal image) acquired in a state where the fundus is arranged behind the depth position where the optical path lengths of the measurement light and the reference light match, and the optical path of the measurement light and the reference light. It has a mode (retinal mode, choroidal mode) in which a tomographic image (reverse image) acquired with the fundus placed in front of the depth position where the lengths match is output to a monitor, respectively.

Japanese Unexamined Patent Publication No. 2010-29648 Japanese Unexamined Patent Publication No. 2007-215733 Japanese Unexamined Patent Publication No. 2013-156229

However, when the analysis result is obtained based on the acquired tomographic image, a good analysis result may not be obtained. Alternatively, the acquired tomographic image may not be sufficiently analyzed.

The technical subject of the present disclosure is to solve at least one problem of the prior art.

In order to solve the above problems, the present disclosure is characterized by having the following configurations.

(1)
An OCT data processing program executed in an OCT data processing apparatus that processes three-dimensional OCT data obtained by an optical coherence tomography apparatus including a Fourier domain OCT optical system.
By being executed by the processor of the OCT data processor,
It is an analysis processing step for performing a segmentation process on the three-dimensional OCT data, analyzing the subject based on the result of the segmentation process, and displaying the analysis result of the subject.
The OCT data processing apparatus performs an analysis processing step of changing the segmentation region for the three-dimensional OCT data according to the difference in the imaging method of the optical coherence tomography apparatus when the three-dimensional OCT data is acquired by the optical coherence tomography apparatus. To execute,
The analysis processing step is performed according to the difference in the appearance image due to the difference in sensitivity in the depth direction between the 3D OCT data acquired by SD-OCT and the 3D OCT data acquired by SS-OCT. It is characterized in that the segmentation region with respect to the three-dimensional OCT data is changed.
(2)
3 Obtained by an optical coherence tomography apparatus including a Fourier domain OCT optical system for detecting an A scan signal due to interference between a measurement light scanned on a subject by a scanning means and a reference light corresponding to the measurement light. An OCT data processing device that processes dimensional OCT data.
An analysis processing means for performing a segmentation process on the three-dimensional OCT data, analyzing the subject based on the result of the segmentation process, and displaying the analysis result of the subject is provided.
The analysis processing means is an analysis processing means that changes the segmentation region for the three-dimensional OCT data according to the difference in the imaging method of the optical coherence tomography device when the three-dimensional OCT data is acquired by the optical coherence tomography device. The three-dimensional OCT data acquired by SD-OCT and the three-dimensional OCT data acquired by SS-OCT correspond to the difference in the appearance image due to the difference in sensitivity in the depth direction. It is characterized in that the segmentation area for OCT data is changed.

It is a block diagram which shows an example of the optical coherence tomography apparatus which concerns on this embodiment (hereinafter, may also be referred to as this apparatus). It is a figure which shows an example of the OCT optical system which concerns on this embodiment. It is a figure which shows an example of the OCT data acquired (formed) by an OCT optical system. It is a figure which shows an example of the OCT data stored in the memory 72 as analysis data.

Hereinafter, one of the typical embodiments will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of an optical coherence tomography apparatus (hereinafter, may be referred to as this apparatus) according to the present embodiment. As an example, this device 10 shows an application example to a fundus photography device that acquires a tomographic image of the fundus of the eye to be inspected.

<First Example>
The OCT device 1 shown in FIG. 1 processes, for example, a detection signal acquired by the OCT optical system 100. The OCT optical system 100 obtains, for example, OCT data (for example, a fundus tomographic image) of the fundus Ef of the eye E to be inspected. The OCT optical system 100 is connected to, for example, the control unit 70.

Next, an example of the OCT optical system 100 will be described with reference to FIG.

<OCT optical system>
The OCT optical system 100 has, for example, a device configuration of an optical coherence tomography (OCT) for ophthalmology, and may be provided to obtain OCT data of the eye to be inspected. As an example of a more detailed configuration, the OCT optical system 100 divides the light emitted from the light source 102 into measurement light and reference light by an optical divider (for example, a coupler or a circulator) 104. The OCT optical system 100 guides the measurement light to the fundus Ef of the eye E by the measurement optical system 106, and guides the reference light to the reference optical system 110. The OCT optical system 100 causes the detector (light receiving element) 120 to receive the interference light obtained by combining the measurement light reflected by the fundus Ef and the reference light. The detector 120 detects an interference signal between the measurement light and the reference light.

In the case of Fourier domain OCT, the spectral intensity (spectral interference signal) of the interference light is detected by the detector 120, and the complex OCT signal is acquired by the Fourier transform on the spectral intensity data. For example, the A scan signal (eg, depth profile) is acquired by calculating the absolute value of the amplitude in the complex OCT signal. The measurement light is scanned on the fundus by the optical scanner 108. OCT data (for example, tomographic image data) is acquired by arranging the A scan signals at each scanning position.

As the OCT optical system 100, a spectral domain type OCT optical system may be used, or a swept source type (SS-OCT) that detects a spectrum of interference light using a variable wavelength light source is used. You may.

In the case of SD-OCT, a low coherent light source (broadband light source) is used as the light source 102, and the detector 120 is provided with a spectroscopic optical system (spectrum meter) that disperses the interference light into each frequency component (each wavelength component). .. The spectrum meter includes, for example, a diffraction grating and a line sensor.

In the case of SS-OCT, a wavelength scanning light source (wavelength variable light source) that changes the emission wavelength at high speed in time is used as the light source 102, and for example, a single light receiving element is provided as the detector 120. The light source 102 is composed of, for example, a light source, a fiber ring resonator, and a wavelength selection filter. Then, as a wavelength selection filter, for example, a combination of a diffraction grating and a polygon mirror, and a filter using Fabry-Perot Etalon can be mentioned.

The light emitted from the light source 102 is divided into measurement light and reference light by the light divider 104. The measurement light may be emitted into the air after passing through the optical fiber. The measurement light may be focused on the fundus Ef via the optical scanner 108 and other optical members of the measurement optical system 106. The light reflected by the fundus Ef may be returned to the optical fiber through the same optical path.

The optical scanner 108 may scan the measurement light in the transverse direction on the fundus, or may scan the measurement light two-dimensionally on the fundus. The optical scanner 108 may be arranged at a position substantially conjugate with the pupil. The optical scanner 108 is, for example, two galvanometer mirrors, and the reflection angle thereof may be arbitrarily adjusted by the drive mechanism 50. As the optical scanner 108, for example, a reflection mirror (galvano mirror, polygon mirror, resonant scanner), an acoustic optical element (AOM) that changes the traveling (deflection) direction of light, and the like are used.

The reference optical system 110 can generate a reference light that is combined with the reflected light acquired by the reflection of the measurement light at the fundus Ef. The reference optical system 110 may be of the Michaelson type or the Machzenda type. The reference optical system 110 is formed by, for example, a reflective optical system (for example, a reference mirror), reflects the light from the optical divider 104 by the reflective optical system, returns the light to the optical divider 104, and guides the light to the detector 120. You may. As another example, the reference optical system 110 may be formed by a transmission optical system (for example, an optical fiber) and may be guided to the detector 120 by transmitting the light from the optical divider 104 without returning it.

The reference optical system 110 may have a driving unit 112 for changing the optical path length difference between the measurement light and the reference light by moving the optical member in the reference optical path, for example. For example, the reference mirror is moved in the optical axis direction. The configuration for changing the optical path length difference may be arranged in the measurement optical path of the measurement optical system 106. That is, the device of the present embodiment may be provided with a structure for changing the optical path length of at least one of the measurement light and the reference light.

<Front observation optical system>
The front observation optical system 200 may be provided to obtain a front image of the fundus Ef. The observation optical system 200 may include, for example, a device configuration of a so-called scanning electron ophthalmoscope (SLO) for ophthalmology. The observation optical system 200 may have a so-called fundus camera type configuration. Further, the OCT optical system 100 may also be used as the observation optical system 200.

<Focus target projection unit>
The fixation target projection unit 300 may have an optical system for guiding the line-of-sight direction of the eye E. The fixation target projection unit 300 has an fixation target presented to the eye E, and can guide the eye E in a plurality of directions.

<Control system>
The control unit 70 may include a CPU (processor), RAM, ROM, and the like. More specifically, the CPU of the control unit 70 controls the entire device (OCT device 1, OCT optical system 100) such as each member of each configuration. The RAM temporarily stores various types of information. The ROM of the control unit 70 stores various programs, initial values, and the like for controlling the operation of the entire device. The control unit 70 may be composed of a plurality of control units (that is, a plurality of processors).

A non-volatile memory (hereinafter, memory) 72, an operation unit (control unit) 76, a display unit (monitor) 75, and the like as an example of the storage unit may be electrically connected to the control unit 70. The memory 72 may be a non-transient storage medium capable of retaining the storage contents even when the power supply is cut off. For example, any one of the hard disk drive, the flash ROM, the OCT device 1, and the USB memory may be used as the memory 72.

The memory 72 may store an analysis processing program for analyzing the eye to be inspected based on the OCT data obtained by the OCT device 1. Further, the memory 72 may store a photographing control program for controlling the photographing of the front image and the tomographic image by the OCT optical system 100. Further, the memory 72 may store various information related to imaging such as OCT data, information on the imaging position of the fundus front image and the tomographic image. Various operation instructions by the examiner may be input to the operation unit 76.

The operation unit 76 may output a signal corresponding to the input operation instruction to the control unit 70. For the operation unit 74, for example, at least one of a mouse, a joystick, a keyboard, a touch panel, and the like may be used.

The display unit 75 may be a display mounted on the main body of the device or a display connected to the main body. A display of a personal computer (hereinafter referred to as "PC") may be used. A plurality of displays may be used together. Further, the display unit 75 may be a touch panel. When the display unit 75 is a touch panel, the display unit 75 functions as an operation unit. The display unit 75 displays OCT data, front image data, and the like acquired by the OCT optical system 100.

FIG. 3 is a diagram showing an example of OCT data acquired (formed) by the OCT optical system. The zero delay position S is a position corresponding to the optical path length of the reference light in the OCT data, and corresponds to a position where the optical path lengths of the measurement light and the reference light match. The OCT data is formed of a first image region G1 corresponding to the back side of the zero delay position S and a second image region corresponding to the front side of the zero delay position S. The first image region G1 and the second image region G2 have a symmetrical relationship with respect to the zero delay position S.

Note that FIG. 3 is an example of OCT data when dispersion correction processing is performed by software. That is, the control unit 70 may perform dispersion correction processing by software on the spectrum data output from the detector 120, or may obtain an A scan signal based on the spectrum data after the dispersion correction. As a result, there is a difference in image quality between the real image and the virtual image. Regarding this point, refer to, for example, Japanese Patent Application Laid-Open No. 2012-223264. The dispersion correction is not limited to software, and optical dispersion correction may be used. In this case, there is no difference in image quality between the real image and the virtual image.

FIG. 3A is an example of OCT data when a highly sensitive normal image on the retina side is acquired. In the above configuration, when the optical path length difference is adjusted so that the retinal surface of the eye E is located behind the zero delay position S, the first OCT data is acquired. The first OCT data includes, for example, a fundus tomographic image (normal image) having a higher sensitivity on the retinal surface Rt side than the choroid Ch side portion.

In this case, the tomographic images formed in the first image region and the second image region are in a state of facing each other. In this case, the real image R is formed in the first image region G1 and the virtual image M (mirror image) is formed in the second image region G2.

FIG. 3B is an example of OCT data when a highly sensitive reverse image on the choroid side is acquired. When the optical path length difference is adjusted so that the back surface of the choroid is arranged in front of the zero delay position, the second OCT data is acquired. The second OCT data includes, for example, a fundus tomographic image (reverse image) having a higher sensitivity on the choroid Ch side than on the retinal surface Rt side.

In this case, the tomographic images formed in the first image region G1 and the second image region G2 are in a state of facing opposite directions. In this case, the real image R is formed in the second image region G2, and the virtual image M (mirror image) is included in the first image region G1.

In the example of FIG. 3, the first OCT data and the second OCT data have an inverse relationship of the acquired fundus image depending on whether the fundus is located on the front side or the back side with respect to the zero delay position S. It's different.

For example, the control unit 70 extracts the image information of either the first image area G1 or the second image area G2 from the OCT data and displays it on the screen of the display unit 75. For example, the control unit 70 may cut out the image area from the OCT data, or may create an image again from the luminance information corresponding to the image area.

<Operation explanation>
Next, an example of the operation of the device according to the present embodiment will be described. The examiner instructs the subject to gaze at the fixation target and then performs alignment with respect to the fundus. When the frontal image of the fundus is displayed on the display unit 75, the OCT data is acquired by the OCT optical system 100 based on the preset scanning pattern, and the OCT image is displayed on the display unit 75.

The control unit 70 controls the drive of the drive mechanism 112 based on the detection signal output from the detector 120, and adjusts the optical path length difference between the measurement light and the reference light so that the fundus tomographic image is acquired. The retina mode is set as the initial setting, and the control unit 70 adjusts the optical path length so that the retina Rt is arranged behind the zero delay position S, for example. In this case, the first OCT data is acquired. On the other hand, when observing the fundus tomography in the choroid mode, the control unit 70 adjusts the optical path length difference between the measurement light and the reference light so that the choroid Ch is arranged in front of the zero delay position S. In this case, the second OCT data is acquired.

<Memory of tomographic image> The scanning position / pattern desired by the examiner is set in the state where the first OCT data or the second OCT data is displayed as a moving image. After that, a predetermined trigger signal is automatically or manually output. With this as a trigger, the control unit 70 controls the optical scanner 108 based on the set imaging conditions (for example, scanning position / pattern). The control unit 70 acquires OCT data as a still image based on the output signal from the detector 120 at each scanning position. The control unit 70 stores the acquired OCT data in the memory 72. In this case, the control unit 70 may store the determination information of whether the OCT data is the first OCT data or the second OCT data in the memory 72 in association with the stored OCT data. The discrimination information can be acquired by the mode switching signal between the retinal mode and the choroidal mode, the acquisition position of the real image, and the like.

When storing the OCT data in the memory 72, for example, the control unit 70 extracts the image information of either the first image area G1 or the second image area G2 from the OCT data and stores it in the memory 72. May be good. For example, in the first OCT data, the OCT data corresponding to the first image area G1 is stored in the memory 72 (see FIG. 4A), and in the second OCT data, the OCT data corresponding to the second image area G2 is stored. The OCT data to be used may be stored in the memory 72 (see FIG. 4B).

<Segmentation>
In the present embodiment, when performing analysis, the control unit 70 may perform a segmentation process on the OCT data stored in the memory 72, and analyze the fundus Ef based on the result of the segmentation process. In this case, the control unit 70 is used as an example of the analysis processing unit. The segmentation process is used, for example, as an image process for extracting features in OCT data as a preparation for obtaining an analysis result of the fundus.

The control unit 70 may detect (extract) at least one of the boundaries of a plurality of layers as a segmentation process, for example. More specifically, the control unit 70 controls a specific layer (for example, nerve fiber layer (NFL), ganglion cell layer (GCL), retinal pigment epithelium (RPE), etc.). ), The layer boundary corresponding to the choroid may be detected (extracted) by a segmentation process. When detecting the layer boundary corresponding to a specific layer, the detection method is set based on the position of the specific layer based on the anatomical point of view, the order of the layers, the brightness level in the A scan signal, and the like. For segmentation, for example, edge detection or the like is used.

<Change of segmentation process>
The control unit 70 may change at least a part of the segmentation process for the OCT data between the first OCT data and the second OCT data in which the positional relationship of the fundus with respect to the zero delay position S is different from each other. Here, the first OCT data is, for example, OCT data acquired in a state where the fundus surface is arranged on the back side of the zero delay position S. Further, the second OCT data is, for example, OCT data acquired in a state where the back surface of the fundus is arranged in front of the zero delay position S.

In the present embodiment, both the first OCT data and the second OCT data include OCT data relating to the same site (for example, fundus) of the eye to be inspected. In the following description, the vertical direction in the OCT data will be described by defining the fundus surface (retina surface layer) side as the upward direction (front side) and the fundus back surface (choroidal layer) side as the downward direction (back side).

Here, the control unit 70 may change the segmentation area, for example. As an example, the control unit 70 may change the segmentation region in consideration of the difference in the noise position with respect to the fundus tomographic image between the first OCT data and the second OCT data. In this case, the area excluded from the segmentation process in the OCT data may be changed.

FIG. 4 is a diagram showing an example of OCT data stored in the memory as analysis data. In the acquired OCT data, in addition to the OCT data of the eye to be inspected such as a fundus tomographic image, a noise component NZ caused by the device may be generated. Such a noise component is noise that is not removed by noise removal processing such as DC subtraction and remains in the OCT data. Possible causes of such noise include, for example, fluctuation of light from the light source 102, fluctuation / vibration of the device, reflection of the internal lens, light from external lighting, and the like.

The noise component NZ often has a constant periodicity, and is formed at a predetermined position with respect to the zero delay position, for example. As a result, the noise component NZ generated on the first OCT data is formed at a position separated from the upper end of the OCT data (that is, the end on the surface layer side of the retina) by a predetermined distance D. That is, the noise component NZ is generated above the OCT data of the fundus of the eye to be inspected. The noise component NZ generated on the second OCT data is formed at a position separated by a predetermined distance D from the lower end (that is, the choroid side end portion) of the OCT data. That is, the noise component NZ is generated below the OCT data of the fundus of the eye to be inspected.

In the present embodiment, the area where the segmentation process is executed is changed in consideration of the difference in the generation position of the noise component NZ with respect to the OCT data of the fundus of the eye to be inspected. In FIG. 4, the segmentation execution area (hereinafter, execution area) SG is an area in which segmentation is executed on the OCT data. When the execution area SG is set, for example, the coordinate position in the depth direction from the start point SG1 at which the segmentation is started to the end point SG2 at the end of the segmentation may be stored in the memory 72 in advance. As a result, segmentation is performed from the start point SG1 to the end point SG2 in each A scan signal, and segmentation is not performed for the other regions.

When segmentation is performed on the first OCT data, for example, the start point SG1 is set below the upper end of the OCT data (that is, the end on the surface layer side of the retina) by a predetermined distance D. , The lower end of the OCT data (that is, the choroid side end) is set to the end point SG2 (see FIG. 3A). As a result, segmentation is performed so as to exclude the noise component NZ included in the first OCT data.

On the other hand, when segmentation is performed on the second OCT data, for example, the upper end of the OCT data (that is, the surface layer side of the retina) is set to the start point SG1, and the lower end (that is, the choroid side end) of the OCT data is above the upper end. The end point SG2 is set further above the position separated by a predetermined distance D. As a result, segmentation is performed so as to exclude the noise component NZ included in the second OCT data.

As shown above, by performing segmentation so that the noise component NZ is excluded according to the position where the noise component NZ is generated on the OCT data of the fundus of the eye to be inspected, the influence of noise is affected regardless of the characteristics of the OCT data. Can be reduced appropriately. Subsequent analysis can be performed well.

<Analysis based on segmentation results>
In the case of the first OCT data, the surface side of the fundus (for example, the retinal portion) is clearly formed. As a result of the segmentation, the control unit 70 acquires the layer boundary information in each layer of the retinal layer (for example, the retinal surface layer to the retinal pigment information layer) and calculates the thickness information of each layer based on the acquired layer boundary information. It may be. If the choroid can be segmented, the thickness of the choroid may be determined in addition to measuring the thickness of the retinal layer.

In the case of the second OCT data, the back surface side of the fundus (for example, the choroidal part) is clearly formed. As a result of the segmentation, the control unit 70 may acquire the layer boundary information in the choroidal layer and calculate the thickness information of the choroidal layer based on the acquired layer boundary information. When each layer of the retina can be segmented, the thickness of each layer of the retina may be obtained in addition to the measurement of the thickness of the choroidal layer.

The fundus analysis based on the result of the segmentation process is not limited to the above. For example, size measurement, lesion detection, and the like may be performed on a characteristic site of the fundus (for example, macula, papilla). Further, the control unit 70 may acquire an En-face image (OCT front image) in each layer by using the result of the segmentation.

Of course, the OCT data may be three-dimensional OCT data. The three-dimensional OCT data is acquired by, for example, a two-dimensional scan of the measurement light (for example, a raster scan). In addition, an analysis map may be acquired as a result of segmentation for 3D OCT data. As the analysis map, for example, a network thickness map, a choroid thickness map, and the like can be considered.

The control unit 70 may display the analysis result acquired as described above on the display unit 75.

<Example of transformation>
In the above embodiment, the surface layer side of the retina is set to the start point SG1, but the present invention is not limited to this, and the choroid side may be set to the start point SG1. The execution area SG may be set at the manufacturing stage of the device. Further, the position of the execution area SG may be set for each device in consideration of individual differences of the devices.

Further, in the above example, the region where the segmentation is executed is changed according to the position where the noise component NZ is generated with respect to the OCT data of the eye to be inspected, but the method for changing the segmentation region is not limited to this. For example, the present embodiment can be applied even when the OCT data for performing the segmentation processing is extracted and the segmentation is performed on the extracted OCT data. For example, the control unit 70 may change the extraction area for performing the segmentation process according to the position where the noise component NZ is generated. Further, the control unit 70 may exclude the noise component from the segmentation process in advance by storing the OCT data in the memory 75 so that the noise component NZ is excluded. In this case, the storage area on the OCT data may be preset so that the noise component NZ is excluded.

In the above description, the image area stored in the memory 72 is changed between the first OCT data and the second OCT data, but the present invention is not limited to this. The image areas stored in the memory 72 may be the same. Such a storage method may be used when obtaining OCT data by optical dispersion correction, or when switching the dispersion correction data between the first OCT data and the second OCT data. In this case, the OCT data corrected by the software dispersion correction process may be switched between a real image and a virtual image (for details, refer to Japanese Patent Application Laid-Open No. 2012-223264). Even in such a case, since the vertical position of the noise with respect to the image to be inspected is different between the first OCT data and the second OCT data, the above embodiment can be applied.

When displaying a part of the OCT data based on the segmentation result, the control unit 70 changes the display area of the OCT data between the first OCT data and the second OCT data. May be good.

For example, when displaying a 3D graphic image on the display unit 75 based on the 3D OCT data, the control unit 70 changes the area to be displayed as the 3D graphic image with reference to the layer boundary area detected by the segmentation. You may do so. More specifically, when displaying the first three-dimensional OCT data, the control unit 70 removes the region above the retinal surface layer and displays a graphic image with respect to the region below the retinal surface layer. You may. Further, when displaying the second three-dimensional OCT data, the control unit 70 may remove the region below the choroidal layer and display a graphic image with respect to the region above the choroidal layer. As a result, unnecessary noise information in the three-dimensional graphic image is suitably reduced.

The processing of the present embodiment may be performed on the full-range OCT data in which either the real image or the virtual image is removed by the image processing.

In the above description, at least a part (for example, a segmentation region) of the segmentation process for the OCT data is performed between the first OCT data and the second OCT data having different positional relationships of the fundus with respect to the zero delay position. Changed, but not limited to this. In this embodiment, at least a part of the segmentation process may be changed depending on the difference in the conditions when the OCT data is acquired by the optical coherence tomography apparatus.

As a first example, the control unit 70 may change the segmentation process according to the difference in the imaging method of the optical coherence tomography apparatus. For example, the first OCT data is the OCT data acquired by the spectral domain OCT (SD-OCT), and the second OCT data is the OCT data acquired by the sweep source OCT (SS-OCT). In some cases, the brightness of the acquired image is different. Possible causes include differences in the imaging principle and differences in the wavelength of the light source. Therefore, the control unit 70 may change the threshold value when performing segmentation between the first OCT data and the second OCT data, for example. This will ensure proper segmentation. Such processing is also applicable in the first embodiment.

In addition, the appearance image may differ due to the difference in sensitivity in the depth direction. The appearance image means an image that appears as an eye test image in the OCT data, and the difference in the appearance image means a difference in the eye test data that appears in the OCT data according to the difference in the acquisition conditions. Here, the appearance image may be defined as, for example, an image imaged to the extent that segmentation can be performed.

Therefore, the control unit 70 may change the segmentation region between the first OCT data and the second OCT data. That is, in the present embodiment, the segmentation region may be changed according to the difference in the appearance image in the OCT data. This enables proper analysis processing. Such processing is also applicable in the first embodiment.

As a second example, the control unit 70 may change the segmentation process according to the difference in the exposure time of the light receiving element when acquiring the OCT data. For example, when the first OCT data is the OCT data acquired at the first exposure time and the second OCT data is the OCT data acquired at the second exposure time, it is acquired. The brightness of the image is different. Therefore, the control unit 70 may change the threshold value when performing segmentation between the first OCT data and the second OCT data.

In the above description, the case of acquiring the morphological tomographic image of the eye to be inspected has been described, but the control unit 70 measures changes between signals (for example, phase change, intensity change) in a plurality of A scan signals. Thereby, a blood flow measurement image (Doppler OCT image) may be acquired. Further, the control unit 70 may acquire an image (polarized OCT image) showing the polarization characteristics of the eye to be inspected by measuring the polarization components (S polarization, P polarization) in the plurality of A scan signals. That is, this embodiment can also be applied to OCTs such as Doppler OCT and polarization-sensitive OCT.

Further, in the above description, the device for obtaining OCT data of the fundus of the eye has been described as an example, but the present invention is not limited to this, and the present embodiment can be applied to any device for obtaining OCT data of a predetermined part of the eye to be inspected. It is possible. For example, it is used in an apparatus for obtaining OCT data of the anterior segment of the eye to be inspected.

Further, the application of this embodiment is not limited to the application to an ophthalmologic imaging apparatus, but also to an OCT apparatus that acquires a tomographic image of a living body (for example, skin, blood vessel) other than the eye, or a sample other than the living body. It is possible.

1 OCT device 70 Control unit 100 OCT optical system S Zero delay position NZ noise SG segmentation execution area

Claims (2)

An OCT data processing program executed in an OCT data processing apparatus that processes three-dimensional OCT data obtained by an optical coherence tomography apparatus including a Fourier domain OCT optical system.
By being executed by the processor of the OCT data processor,
It is an analysis processing step for performing a segmentation process on the three-dimensional OCT data, analyzing the subject based on the result of the segmentation process, and displaying the analysis result of the subject.
The OCT data processing apparatus performs an analysis processing step of changing the segmentation region for the three-dimensional OCT data according to the difference in the imaging method of the optical coherence tomography apparatus when the three-dimensional OCT data is acquired by the optical coherence tomography apparatus. To execute,
The analysis processing step is performed according to the difference in the appearance image due to the difference in sensitivity in the depth direction between the 3D OCT data acquired by SD-OCT and the 3D OCT data acquired by SS-OCT. An OCT data processing program characterized by changing the segmentation region for the three-dimensional OCT data. 3 Obtained by an optical coherence tomography apparatus including a Fourier domain OCT optical system for detecting an A scan signal due to interference between a measurement light scanned on a subject by a scanning means and a reference light corresponding to the measurement light. An OCT data processing device that processes dimensional OCT data.
An analysis processing means for performing a segmentation process on the three-dimensional OCT data, analyzing the subject based on the result of the segmentation process, and displaying the analysis result of the subject is provided.
The analysis processing means is an analysis processing means that changes the segmentation region for the three-dimensional OCT data according to the difference in the imaging method of the optical coherence tomography device when the three-dimensional OCT data is acquired by the optical coherence tomography device. The three-dimensional OCT data acquired by SD-OCT and the three-dimensional OCT data acquired by SS-OCT correspond to the difference in the appearance image due to the difference in sensitivity in the depth direction. An OCT analysis processing apparatus characterized by changing the segmentation region for OCT data.

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