JP6760310B2 - Image data processing device, image data processing method, and image data processing program - Google Patents

Description

The present disclosure relates to an image data processing apparatus for processing image data of a test object, an image data processing method, and an image data processing program.

Conventionally, there is known a technique of measuring the displacement of a test object in an imaging region by processing the image data of the test object. For example, the displacement measuring device disclosed in Patent Document 1 uses the correspondence between the displacement amount of a minute region in the axial direction and the lateral direction of the photographing optical axis and the attenuation of the correlation coefficient between a plurality of tomographic images. Measure the amount of displacement of a minute region in the axial and lateral directions.

Japanese Unexamined Patent Publication No. 2015-169650

In the conventional technique, the measured displacement of the test object is treated as a vector field. However, in the vector field, it may be difficult to appropriately grasp information on the displacement of each part in the imaging region (for example, visualization, qualification, quantification, etc.).

A typical object of the present disclosure is to provide an image data processing apparatus, an image data processing method, and an image data processing program capable of appropriately grasping information regarding displacement of a test object.

The image data processing apparatus provided by the typical embodiment in the present disclosure includes a control unit that controls the processing of the image data, and the control unit is a plurality of acquired at different times with respect to the target imaging position of the subject. From the image data, a vector field indicating the displacement of each of the plurality of parts in the imaging region is calculated, and the potential field is calculated by performing Helmholtz decomposition on the vector field.

The image data processing method provided by the typical embodiment in the present disclosure is an image data processing method executed by an image data processing apparatus, and a plurality of images acquired at different times with respect to a target photographing position of an object. A vector field calculation step that calculates a vector field indicating the displacement of each of a plurality of parts in the imaging region from the data, and a potential field calculation step that calculates a potential field by performing Helmholtz decomposition on the vector field. including.

The image data processing program provided by the typical embodiment in the present disclosure is an image data processing program executed in an image data processing apparatus, and the processor of the image data processing apparatus executes the image data processing program. In the vector field calculation step of calculating the vector field indicating the displacement of each of the plurality of parts in the imaging area from the plurality of image data acquired at different times with respect to the target imaging position of the test object, and the vector field. On the other hand, the image data processing apparatus is made to execute a potential field calculation step of calculating a potential field by performing Helmholtz decomposition.

According to the image data processing apparatus, the image data processing method, and the image data processing program according to the present disclosure, information on the displacement of the test object can be appropriately grasped.

In the embodiment illustrated in the present disclosure (hereinafter, “the present embodiment”), the control unit of the image data processing device is within the imaging region from a plurality of image data acquired at different times with respect to the target imaging position of the subject. A vector field indicating the displacement of each of the plurality of parts in is calculated. The control unit calculates the potential field by performing Helmholtz decomposition on the vector field. According to the calculated potential field, at least one of the field without rotation and the field without divergence is grasped. Therefore, at least one of visualization, qualification, quantification, and the like of information regarding the displacement of each part in the imaging region is appropriately performed.

The control unit may calculate a scalar potential field, which is a potential field showing the distribution of energy that causes displacement in the test object, by performing Helmholtz decomposition on the vector field. According to the scalar potential field, the distribution of energy that causes displacement is clearly shown. Therefore, information on the displacement of the test object can be grasped more appropriately.

The control unit may calculate a vector potential field without divergence by performing Helmholtz decomposition on the vector field. In this case, information about rotation at each part is appropriately grasped.

Based on the calculated scalar potential field, the control unit may create image data that displays the distribution of energy that causes displacement in the test object. In this case, the image data processing device can easily and appropriately allow the user to grasp the information regarding the displacement of the test object. In this case, for example, the information regarding the displacement can be appropriately grasped by the user without performing processing such as creating images separately according to the direction of the displacement.

The plurality of image data from which the vector field is calculated may be image data (OCT image data) acquired by using optical coherence tomography (OCT). In this case, the image data processing apparatus can appropriately grasp information on the internal displacement of the test object.

The vector field may be calculated from image data other than OCT image data. For example, an optical scanner that scans the measurement light two-dimensionally on the test object and a light receiving element that receives the reflected light from the test object through a confocal opening arranged at a position substantially conjugate with the test object. Image data acquired by a scanning apparatus (Scanning Laser Optimalmoscope: SLO) may be used. Image data acquired by an imaging device (for example, a fundus camera or the like) that captures a two-dimensional region on the surface of the test object may be used. In these cases, information on the displacement of the surface of the test object is properly grasped.

The control unit calculates a two-dimensional vector field in the direction (axial direction) along the optical axis of the photographing light emitted from the OCT device and in the lateral direction intersecting the axial direction, and the potential field is calculated from the two-dimensional vector field. May be calculated. However, even when a one-dimensional vector field or a three-dimensional vector field is used, at least a part of the technique illustrated in this embodiment can be applied.

The control unit may analyze the displacement generated in the test object from the potential field calculated by the Helmholtz decomposition. In this case, for example, the displacement is appropriately analyzed without performing a process of analyzing the displacement separately according to the direction of the displacement. Various methods can be adopted as the analysis method. The analysis may be a qualitative analysis or a quantitative analysis.

The image data processing device may execute both the image data creation process for displaying the energy distribution and the displacement analysis process for the test object. However, as a matter of course, the image data processing apparatus does not need to execute both the image data creation process and the displacement analysis process. Further, the device for calculating the potential field and the device for executing the image data creation process or the displacement analysis process may be different devices. For example, the PC may create image data based on the potential field calculated by the OCT apparatus.

The plurality of image data from which the vector field is calculated may include image data acquired with respect to the position of the subject to be irradiated with the therapeutic light. In this case, the image data processing apparatus can appropriately grasp the information regarding the displacement of the test object irradiated with the therapeutic light by calculating the potential field.

In addition, the control unit may determine the suitability of the energy of the therapeutic light applied to the test object by analyzing the displacement generated in the test object from the potential field. In this case, the image data processing device determines the suitability of the energy of the therapeutic light from the displacement of the test object generated by the irradiation of the therapeutic light while suppressing various influences such as individual differences in the living body. Can be done.

However, even when processing image data other than the image data of the test object irradiated with the therapeutic light, at least a part of the techniques exemplified in the present embodiment can be adopted. For example, when some energy (for example, ultrasonic energy, electromagnetic wave energy, wind pressure energy, etc.) is added to the test object and the properties of the test object (for example, hardness, internal pressure, etc.) are measured. At least a part of the technique exemplified in this embodiment can be applied. In addition, at least a part of the techniques exemplified in this embodiment can be applied to the case of processing image data of an object other than the eye.

Further, the control unit may execute a process of returning the potential field calculated by performing Helmholtz decomposition on the vector field to the vector field again. For example, the control unit may calculate the vector field from which the rotation component and the noise are removed by differentiating the scalar potential field calculated by the Helmholtz decomposition with respect to the vector field. In this case, the finally calculated vector field makes it easier to quantify the displacement. The control unit may execute a process of returning the potential field to the vector field after performing a smoothing process or the like on the potential field.

The image data processing device exemplified in the present embodiment is an optical coherence tomography device (OCT device) that acquires internal information (for example, a tomographic image) of a test object by interference light in which measurement light and reference light are combined. .. However, another device may process the image data as an image data processing device. For example, the image data processing device may be a personal computer (hereinafter referred to as “PC”), a server, a mobile terminal, or the like connected to the OCT device. The image data processing device may be a PC or the like capable of acquiring image data taken by a photographing device such as an OCT device via wired communication, wireless communication, a detachable memory, or the like. The image data processing device may be a treatment device capable of both photographing the test object and treating the test object with therapeutic light. Further, a plurality of devices may function as image data processing devices. For example, the OCT apparatus may execute the process of calculating the vector field, and the PC may execute the process of calculating the potential field from the vector field. In this case, both the OCT device and the PC function as the image data processing device.

It is the schematic for demonstrating the structure of the image data processing apparatus 1 of this embodiment. It is the schematic which shows the structure of the OCT optical system 100, the front observation optical system 200, and the therapeutic light irradiation optical system 300 of this embodiment. It is a flowchart of image data processing executed by the image data processing apparatus 1 of this embodiment. It is a figure which shows an example of the displacement energy distribution image created by the image data processing apparatus 1.

Hereinafter, an example of a typical embodiment in the present disclosure will be described with reference to the drawings. First, with reference to FIG. 1, a schematic configuration of the image data processing device (image data processing system) 1 of the present embodiment will be described. The image data processing device 1 of the present embodiment acquires a signal (for example, an OCT signal) by the OCT optical system (interfering optical system) 100, and acquires image data from the acquired signal. That is, the image data processing device 1 of the present embodiment has a function as an OCT device that acquires internal information of the test object. The image data processing device 1 calculates a vector field and a potential field by processing the image data. Further, the image data processing device 1 of the present embodiment also has a function as a treatment device for irradiating a test object (eye E in the present embodiment) which is a living body with therapeutic light (for example, therapeutic laser light).

The image data processing device 1 of the present embodiment includes a control unit 10, a display unit 21, an operation unit 22, an OCT optical system 100, a front observation optical system 200, and a therapeutic light irradiation optical system 300.

The control unit 10 controls the processing of the image data processing device 1 (for example, various data processing and operation processing). The control unit 10 includes a CPU (processor) 11, a ROM 12, a RAM 13, and a non-volatile memory (NVM) 14. The CPU 11 controls various controls in the image data processing device 1. Various programs, initial values, and the like are stored in the ROM 12. The RAM 13 temporarily stores various types of information. The non-volatile memory 14 is a non-transient storage medium capable of retaining the stored contents even when the power supply is cut off. For example, a hard disk drive, a flash ROM, a detachable USB memory, or the like may be used as the non-volatile memory 14. In the present embodiment, for example, an image data processing program for executing image data processing described later is stored in the non-volatile memory 14.

In the present embodiment, the integrated image data processing device 1 in which the OCT optical system 100, the therapeutic light irradiation optical system 300, the control unit 10, and the like are built in one housing is illustrated. However, it goes without saying that the image data processing device 1 may include a plurality of devices having different housings. For example, the image data processing device 1 may include an OCT device incorporating an OCT optical system 100 and a PC connected to the OCT device by wire or wirelessly. In this case, both the control unit included in the OCT device and the control unit of the PC may function as the control unit 10 of the image data processing device 1. That is, the control unit 10 may include a plurality of processors. Further, a commercially available PC may be used as a part of the image data processing device 1. In this case, at least a part of the image data processing program can be installed on a commercially available PC. Further, a treatment device provided with the treatment light irradiation optical system 300 may be used separately from the image data processing device.

The display unit 21 may be a display mounted on the device main body, or may be a display separate from the device main body. The operation unit 22 outputs a signal corresponding to the input operation instruction to the control unit 10. For the operation unit 22, for example, at least one of a mouse, a joystick, a keyboard, a touch panel, and the like can be used.

The OCT optical system 100, the front observation optical system 200, and the therapeutic light irradiation optical system 300 will be described with reference to FIG. The OCT optical system 100 has a configuration of a so-called optical coherence tomography (OCT), and is used to acquire internal information (for example, image data of a tomographic image) of a test object (eye E in this embodiment). Used for. The OCT optical system 100 of the present embodiment divides the light emitted from the measurement light source 102 into measurement light (sample light) and reference light by an optical divider (for example, a coupler) 104. The OCT optical system 100 guides the measurement light to the test object (for example, the fundus Ef of the eye E) by the measurement optical system 106, and also guides the reference light to the reference optical system 110. The OCT optical system 100 causes the detector (for example, a light receiving element) 120 to receive the interference light obtained by combining the reference light and the measurement light reflected by the test object.

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, by calculating the absolute value of the amplitude in the complex OCT signal, the depth profile (A scan signal) in a predetermined range is acquired. OCT image data (tomographic image data) is acquired by arranging the depth profiles of the measurement light scanned by the optical scanner 108 at each scanning position. Further, the control unit 10 may acquire three-dimensional OCT image data (three-dimensional tomographic image data) by scanning the measurement light on the tissue in the two-dimensional direction. Further, from the three-dimensional OCT image data, the OCT front (Enface) image data when the structure is viewed from the axial direction (front direction) along the optical axis of the measurement light may be acquired.

As an example of the Fourier domain OCT, Spectral-domain-OCT (SD-OCT), Swept-source-OCT (SS-OCT) and the like can be adopted. Further, for example, Time-domine-OCT (TD-OCT) or the like can be adopted. In the case of SD-OCT, for example, a low coherent light source (broadband light source) is used as the measurement light source 102, and the interference light is separated into each frequency component (each wavelength component) in the vicinity of the detector 120 in the optical path of the interference light. A spectroscopic optical system (spectrometer) is provided. In the case of SS-OCT, for example, as the measurement light source 102, a wavelength sweep light source that changes the emission wavelength at high speed with time is used.

The light emitted from the measurement light source 102 is divided into a measurement luminous flux and a reference luminous flux by the coupler 104. The measurement light passes through the optical fiber and then is emitted into the air. The measurement light emitted into the air is focused on the test object via the optical scanner 108 of the measurement optical system 106 or the like. The measurement light reflected by the test object is returned to the optical fiber through the same optical path.

The optical scanner 108 scans the measurement light in the two-dimensional direction (XY direction) on the tissue. The optical scanner 108 of the present embodiment is arranged at a position substantially conjugated with the pupil of the eye E. As an example, the optical scanner 108 of this embodiment includes two galvanometer mirrors. The reflection angle of the galvano mirror is arbitrarily adjusted by the drive mechanism 50. As a result, the reflection direction of the measurement light emitted from the measurement light source 102 changes, and the measurement light is irradiated to an arbitrary position on the test object. Needless to say, the configuration of the optical scanner 108 can be changed. For example, a polygon mirror, a resonant scanner, an acoustic optical element (AOM), or the like may be adopted for the optical scanner 108.

The reference optical system 110 generates a reference light that is combined with the measurement light reflected by the test object. The reference optical system 110 may be of the Michaelson type or the Machzenda type. The reference optical system 110 of the present embodiment reflects the light incident from the coupler 104 by the reflecting optical system (for example, a reference mirror), so that the light is returned to the coupler 104 and guided to the detector 120. The configuration of the reference optical system 110 can also be changed. For example, the reference optical system 110 may transmit the light incident from the coupler 104 without reflecting it and guide it to the detector 120. The reference optical system 110 can change the optical path length difference between the measurement light and the reference light by moving the optical member in the optical path. In the present embodiment, the optical path length difference is changed by moving the reference mirror in the optical axis direction. The configuration for changing the optical path length difference may be provided in the optical path of the measurement optical system 106.

The front observation optical system 200 acquires front image data of the test object. The front image data may be the data of the completed two-dimensional image, or may be the signal data at each measurement point used for calculating the brightness of each pixel of the two-dimensional image. As an example, the front observation optical system 200 of the present embodiment includes an optical scanner that scans measurement light (for example, infrared light) emitted from a light source in a two-dimensional direction (XY direction) on an object to be examined. It includes an object and a light receiving element that receives reflected light through a confocal aperture arranged at a substantially conjugate position. That is, the front observation optical system 200 of the present embodiment includes a so-called scanning laser ophthalmoscope (SLO) configuration. However, the configuration of the front observation optical system 200 can also be changed. For example, the front observation optical system 200 may have a fundus camera type configuration.

The therapeutic light irradiation optical system 300 irradiates a therapeutic light (therapeutic laser beam in the present embodiment) for treating a living body toward a test object. For example, therapeutic light may be used to coagulate the body. Further, a therapeutic light (for example, a micropulse laser) having a parameter capable of treating a living body with minimal invasiveness may be used. The therapeutic light irradiation optical system 300 may be provided with an optical scanner for therapeutic light (not shown) for scanning the therapeutic light with respect to the subject. In this case, the optical scanner for therapeutic light and the optical scanner 108 of the OCT optical system 100 may be controlled in synchronization. Moreover, the same optical scanner may be used. In the present embodiment, the optical axis of the therapeutic light irradiation optical system 300 is made coaxial with the optical axis of the OCT optical system 100 by an optical path coupling member (for example, a dichroic mirror or the like). The detailed configuration of the OCT including the therapeutic light irradiation optical system 300 is described in, for example, JP2012-213634A, JP2012-135550A, and the like.

The image data processing executed by the image data processing apparatus 1 of the present embodiment will be described with reference to FIGS. 3 and 4. The CPU 11 of the image data processing device 1 executes the image data processing illustrated in FIG. 3 according to the image data processing program stored in the non-volatile memory 14 or the like. In the following description, the case where the subject is the retina of the eye E and information on the displacement of the retina irradiated with the therapeutic light is acquired will be illustrated.

As shown in FIG. 3, the CPU 11 acquires a plurality of image data at different times with respect to the target imaging position of the test object (S1). That is, the CPU 11 photographs the target imaging position of the test object a plurality of times at different times. As described above, in the present embodiment, various processes are performed based on the OCT image data. As an example, the CPU 11 acquires a plurality of OCT image data relating to the same position by scanning the measurement light a plurality of times at the same position (however, it may be displaced in time) of the test object. However, the target shooting positions at which a plurality of image data are acquired do not necessarily have to be the same position. For example, the target shooting position may be set so that the shooting position shifts by a small distance for each shooting. The CPU 11 may acquire data of an image taken by another OCT device by communication or the like.

The CPU 11 calculates a vector field indicating the displacement of each of a plurality of parts (for example, each pixel included in the photographing area) in the photographing area based on the plurality of image data acquired in S1 (S2). The vector field in this embodiment can also be said to be a map (displacement map) that occupies the displacement of each part. There are various methods for calculating a vector field from a plurality of image data. As an example, in the method illustrated in the present embodiment, the CPU 11 calculates the displacement of each portion (micro region) in the axial direction (Z direction) of the photographing optical axis by using the Doppler phase shift information. Further, the CPU 11 uses the correspondence between the displacement of each part in the axial direction and the lateral direction (X direction) of the photographing optical axis and the attenuation of the correlation coefficient between the plurality of tomographic images, and each part in the lateral direction. Calculate the displacement of. As a result, the vector field of each part is calculated. However, the method of calculating the vector field from a plurality of image data can be changed as appropriate. For example, the CPU 11 may calculate a vector field by calculating displacements in all of a plurality of directions (for example, both in the axial direction and the lateral direction) by a correlation coefficient. The displacement of each part may be calculated by a technique such as speckle tracking. Further, although the two-dimensional vector field is calculated in the present embodiment, a one-dimensional or three-dimensional vector field may be calculated.

The method of calculating the vector field in the present embodiment will be described. In the present embodiment, the CPU 11 calculates the correlation coefficient between the two images (two B scans in the present embodiment). The correlation coefficient is indicated by the following (Equation 1). Here, Δx is the lateral displacement, Δz is the axial displacement, C is a constant indicating the influence of the scattering process and the reproducibility of the scanning system, w is the lateral resolution defined by 1 / e2, and Δk is the light source. It is the maximum width at 1 / e2 of the Gaussian spectrum. The correlation coefficient decreases as a function of displacement, which follows the Gaussian function. That is, the correlation coefficient is attenuated in a Gaussian function with respect to the amount of displacement. The CPU 11 of the present embodiment uses one of the plurality of B scans as the reference B scan and the other B scan as the target B scan. The CPU 11 can obtain, for example, a correlation coefficient between the reference B scan and the B scan obtained by shifting the reference B scan by digital processing.

Next, the CPU 11 uses (Equation 1) to calculate the correlation coefficient ρmerement (x, y) between the reference B scan and the target B scan. Further, the CPU 11 calculates the Doppler phase shift Δφ (x, y) between the reference B scan and the target B scan. The Doppler phase shift Δφ (x, y) is indicated by the following (Equation 2).

The CPU 11 calculates the axial displacement Δz by unwrapping the phase shift using the prioritized path tracking method and converting it into the axial displacement using the following (Equation 3). Here, n is the refractive index of the sample, λ is the center wavelength of the light source, and Φunwrapped is the unwrapped phase shift.

Further, when (Equation 1) is solved for the lateral displacement Δx, it is expressed as the following (Equation 4). The CPU 11 calculates the lateral displacement Δx by substituting the correlation coefficient ρmerement (x, y) calculated by the reference B scan and the target B scan and the calculated axial displacement Δz into (Equation 4). .. The method of determining the lateral displacement direction (+ x direction or −x direction) can be appropriately selected. For example, the CPU 11 may determine the direction of lateral displacement based on the increase or decrease in the correlation coefficient when the two B scans are digitally shifted in the + direction and the − direction.

In the present embodiment, the two-dimensional vector field V on the XZ plane is calculated by the process described above. The details of the processing described above are described in, for example, Japanese Patent Application Laid-Open No. 2015-169650.

Next, the CPU 11 calculates the potential field by performing Helmholtz decomposition on the calculated vector field (S3).

The Helmholtz decomposition will be described. Any vector field can be decomposed into a field without rotation and a field without divergence. This theorem is called Helmholtz's theorem. Also, the decomposition of the vector field using Helmholtz's theorem is called Helmholtz's Decomposition. The Helmholtz decomposition method itself has traditionally been used in fields such as electromagnetism.

For example, let V be the vector field (displacement map), φ be the scalar potential, and A be the vector potential. In this case, the displacement map V is represented by the sum of the gradient of the scalar potential and the rotation of the vector field as shown in (Equation 5) below. In (Equation 5), assuming a field without rotation and setting "rot (A) = 0", a scalar potential field is obtained. Further, in (Equation 5), assuming a field without divergence and setting “grad (φ) = 0”, a vector potential field can be obtained.

As an example, in S3 of the present embodiment, a scalar potential field without rotation is calculated from the vector field V as the potential field. The scalar potential field in this embodiment shows the distribution of energy that causes displacement in the test object.

Next, the CPU 11 creates an image displaying the energy distribution (hereinafter referred to as “displacement energy distribution image”) from the calculated scalar potential field. The CPU 11 causes the display unit 21 to display the created scalar potential field (S4).

FIG. 4 shows an example of a displacement energy distribution image (“Scalar potential” at the bottom of FIG. 4). In the displacement energy distribution image illustrated at the bottom of FIG. 4, a color indicating the distribution of energy that causes displacement is superimposed on the two-dimensional image (B scan image). Since FIG. 4 is a black and white image, it is difficult to understand, but the red part is a part having high energy and the blue part is a part having low energy. Therefore, in the test object, displacement occurs from the red portion toward the blue portion. It is also possible to change the mode of the displacement energy distribution image. For example, the magnitude of energy may be expressed not by color but by brightness or numerical value.

The uppermost "Intensity" in FIG. 4 is a captured two-dimensional image (B-scan image). The second row from the top, "In-plane Lateral disc.", Is an image that visualizes the displacement Δx in the lateral direction (X direction) based on the vector field V calculated in S2. In the example shown in FIG. 4, the higher the brightness, the larger the displacement in the + X direction. The third row from the top, "In-plane axial disc.", Is an image that visualizes the displacement Δz in the axial direction (Z direction) based on the vector field V calculated in S2. In the example shown in FIG. 4, the higher the brightness, the larger the displacement in the + Z direction.

As an example, when trying to grasp the displacement in a plurality of directions, it is necessary to grasp the displacement separately according to each direction in the vector field. For example, when creating an image displaying displacement based on a vector field, it is necessary to create images separately according to the direction as illustrated in the second and third stages from the top of FIG. As a result, it becomes difficult for the user to properly grasp the displacement. On the other hand, when the potential field is used, it may be easier to grasp the information regarding the displacement than when the vector field is used. Actually, according to the displacement energy distribution image illustrated in FIG. 4, the user can appropriately grasp the information regarding the displacement of each part from one image.

Next, the CPU 11 analyzes the displacement generated in the test object (specifically, within the imaging range of the image in the test object) from the potential field calculated in S3 (S5). For example, in the example shown in FIG. 4, the test object is irradiated with therapeutic light for 50 ms. In addition, the vector field and the potential field within the imaging range are calculated at the respective timings of 12.5 ms, 50 ms, 50 ms, 100 ms, 200 ms, and 2000 ms after the start of irradiation of the therapeutic light. In the example shown in FIG. 4, the displacement generated in the test object is analyzed by comparing each of the potential fields at a plurality of different timings. For example, in the example shown in FIG. 4, the amount of displacement (expansion) generated from the center to the outside gradually increases with the start of irradiation of the therapeutic light. On the contrary, when the irradiation of the therapeutic light is completed, the amount of displacement (contraction) generated from the outside toward the center gradually increases. Therefore, in the example shown in FIG. 4, the analysis result indicating that the displacement occurs in the order of "irradiation start, expansion, irradiation end, contraction" is acquired.

Needless to say, the displacement analysis method illustrated above is only an example. Therefore, it is possible to change the displacement analysis method. For example, in the example shown in FIG. 4, the displacement is analyzed by comparing each of the potential fields at a plurality of different timings. However, the CPU 11 can also analyze the displacement from one potential field. In this case, for example, it is conceivable to analyze the displacement by analyzing the size of the region where the energy is equal to or higher than the threshold value. Further, in the example shown in FIG. 4, the CPU 11 analyzes the mode of displacement (specifically, the displacement occurs in the order of expansion and contraction) in the test object. However, the CPU 11 may classify the mode of displacement occurring in the test object by another method. For example, the CPU 11 may determine from the potential field which of the displacement modes in the order of "expansion and contraction" and the plurality of displacement modes including the displacement modes in the order of "contraction and expansion" has occurred.

Next, the CPU 11 determines the suitability of the energy of the therapeutic light applied to the test object from the calculated potential field (S6). For example, there are cases where displacement occurs in the order of "expansion and contraction" and cases where displacement occurs in the order of "expansion and contraction", and whether or not the energy of the therapeutic light is appropriate may be determined. In this case, the CPU 11 may determine the suitability of the energy of the therapeutic light depending on whether or not the analyzed displacement mode is the displacement mode in the order of “expansion, contraction”. Further, the CPU 11 analyzes the size of the portion where the energy causing displacement is equal to or more than the threshold value after a lapse of a predetermined time from the start of irradiation of the treatment light, and determines whether or not the size is within a certain range. Therefore, it may be determined whether or not the energy of the therapeutic light is appropriate.

When the CPU 11 determines the suitability of the energy of the therapeutic light, the CPU 11 may determine the parameter of the therapeutic light emitted from the therapeutic light irradiation optical system 300 based on the determination result. For example, when the treatment light is tested on the test object, the CPU 11 may determine the parameter of the treatment light used for the actual treatment from the potential field of the portion where the treatment light is tested. .. Further, when the treatment light is continuously irradiated to a plurality of parts, the CPU 11 may determine the parameter of the treatment light to be irradiated to the next part from the potential field of one part irradiated with the treatment light. .. Further, the CPU 11 may appropriately determine the timing at which the irradiation of the treatment light is terminated by calculating the potential field during the irradiation of the treatment light.

Moreover, in this embodiment, the case where the vector field and the potential field are calculated from the OCT image data is illustrated. However, the vector field and the potential field may be calculated from the image data other than the OCT image data. For example, the vector field and the potential field may be calculated from the image data acquired by the SLO or the photographing apparatus included in the front observation optical system 200.

Further, in the present embodiment, the displacement of the test object is analyzed based on the potential field. However, the CPU 11 may execute a process of returning the potential field calculated by the Helmholtz decomposition for the vector field to the vector field again. For example, the CPU 11 may calculate the vector field from which the rotational component is removed by differentiating the calculated scalar potential field. The CPU 11 may analyze (quantify) the displacement of the test object by, for example, performing a line integral of the recalculated vector field so as to include the irradiation position of the treatment light.

1 Image data processing device 10 Control unit 11 CPU
100 OCT optical system 300 therapeutic light irradiation optical system

Claims (5)

It is an image data processing device
Equipped with a control unit that controls the processing of image data
The control unit
From a plurality of image data acquired at different times with respect to the target imaging position of the test object, a vector field indicating the displacement of each of the plurality of parts in the imaging area is calculated.
An image data processing apparatus characterized in that a potential field is calculated by performing Helmholtz decomposition on the vector field. The image data processing device according to claim 1.
The control unit
An image data processing apparatus characterized in that a scalar potential field, which is a potential field without rotation, is calculated by performing Helmholtz decomposition on the vector field to show the distribution of energy that causes displacement in the test object. The image data processing device according to claim 2.
The control unit
An image data processing apparatus, which creates image data that displays the distribution of energy that causes displacement in the test object, based on the calculated scalar potential field. An image data processing method executed by an image data processing device.
A vector field calculation step for calculating a vector field indicating the displacement of each of a plurality of parts in the imaging region from a plurality of image data acquired at different times with respect to the target imaging position of the test object.
A potential field calculation step for calculating a potential field by performing Helmholtz decomposition on the vector field, and
An image data processing method comprising. An image data processing program executed in an image data processing device.
When the processor of the image data processing device executes the image data processing program,
A vector field calculation step for calculating a vector field indicating the displacement of each of a plurality of parts in the imaging region from a plurality of image data acquired at different times with respect to the target imaging position of the test object.
A potential field calculation step for calculating a potential field by performing Helmholtz decomposition on the vector field, and
An image data processing program, characterized in that the image data processing apparatus is executed.

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