KR102094500B1 - Apparatus and method for generating tomography image - Google Patents

Abstract

According to a tomographic image generating method and a tomographic image generating apparatus performing the same, at least one basic pattern of a spatial light modulator for modulating the phase of an incident light beam is determined according to a pattern in which pixels are arranged, and vertical or horizontal to the basic pattern Spatial shift modulation is performed by shifting the arrangement of pixels by a predetermined number in a direction to obtain a plurality of shift patterns of a basic pattern, and spectrum signals of rays obtained by rays incident on an object passing through the spatial light modulator are obtained. Generate tomographic images for each of the plurality of shift patterns of the basic pattern by using, and select one pattern that generates the clearest tomographic image among the plurality of shift patterns of the basic pattern based on the generated tomographic images, A final tomography image of the object is generated using the selected pattern.

Description

A tomography image generation method and a tomography image generation device. {Apparatus and method for generating tomography image}

The present invention relates to a tomography image generation method and a tomography image generation device that generates tomography images using light.

Light is currently utilized in various fields by using the characteristics of light having monochromaticity, coherence, and directionality. In the bio and medical fields, light is widely used for observation of tissues or cells, diagnosis of diseases, or laser procedures.

By using various characteristics of light as above, high-resolution imaging of living tissues or cells is possible, so that the internal structure can be observed without directly cutting the human body and living things. In the medical field, it is used to easily and safely identify the causes, locations, and progress of various diseases. In tomography imaging of a human body using light, an increase in the depth of light transmission is required to transmit light to cells or tissues deep in the human body or life.

A technical problem to be achieved by at least one embodiment of the present invention is to provide a tomographic image generating method and a tomographic image generating apparatus having an improved transmission depth of light. Another object of the present invention is to provide a recording medium readable by a computer on which a program for executing the method is executed on a computer. The technical problems to be achieved by the tomography image generation method and the tomography image generation apparatus are not limited to the above-described technical problems, and other technical problems may exist.

A method of generating a tomography image according to an aspect of the present invention includes determining at least one basic pattern of a spatial light modulator that modulates a phase of an incident light beam according to a pattern in which pixels are arranged; Obtaining a plurality of shift patterns of the basic pattern by performing spatial shift modulation to shift an arrangement of pixels by a predetermined number in a vertical or horizontal direction with respect to the basic pattern; Generating tomographic images for each of the basic pattern and a plurality of shift patterns of the basic pattern using a spectral signal of rays obtained by rays incident on an object passing through the spatial light modulator; And selecting one pattern for generating the clearest tomographic image among the basic pattern and a plurality of shift patterns of the basic pattern based on the generated tomographic images. And generating a final tomography image of the object using the selected pattern.

An apparatus for generating a tomography image according to an aspect of the present invention includes an optical output unit that emits light rays; A spatial light modulator for modulating the phase of a light beam according to a pattern in which pixels are arranged; Determining at least one basic pattern of the spatial light modulator, and performing spatial shift modulation to move an array of pixels by a predetermined number in a vertical or horizontal direction with respect to the basic pattern to obtain a plurality of shift patterns of the basic pattern And a modulation control unit controlling the spatial light modulator such that each of the basic pattern and a plurality of shift patterns of the basic pattern are sequentially applied to the spatial light modulator; A detector for detecting a spectral signal for each of the basic pattern and a plurality of shift patterns of the basic pattern based on rays obtained by rays incident on the object through the spatial light modulator; An image generator for generating a tomographic image for each of the base pattern and a plurality of shift patterns of the base pattern using the spectrum signal; And an image processing unit that selects one pattern for generating the clearest tomographic image among the basic pattern and a plurality of shift patterns of the basic pattern based on the generated tomographic images. A final tomography image of the object is generated by using a spectrum signal of rays obtained by applying the selected pattern to an optical modulator.

An optical coherence tomography apparatus according to another aspect of the present invention includes an optical output unit that emits light; A spatial light modulator for modulating the phase of a light beam according to a pattern in which pixels are arranged; Determining at least one basic pattern of the spatial light modulator, and performing spatial shift modulation to move an array of pixels by a predetermined number in a vertical or horizontal direction with respect to the basic pattern to obtain a plurality of shift patterns of the basic pattern And a modulation control unit controlling the spatial light modulator such that each of the basic pattern and a plurality of shift patterns of the basic pattern are sequentially applied to the spatial light modulator; An interferometer that separates the light beam output from the light output unit into a measurement light beam and a reference light beam, irradiates the measurement light beam to an object, and receives a response light beam reflected from the object and returned; A detector configured to detect an interference signal generated by the response light beam and the reference light beam, and detect spectrum signals for each of the base pattern and a plurality of shift patterns of the base pattern based on the interference signal; An image generator for generating a tomographic image for each of the base pattern and a plurality of shift patterns of the base pattern using the spectrum signal; And an image processing unit that selects one pattern for generating the clearest tomographic image among the basic pattern and a plurality of shift patterns of the basic pattern based on the generated tomographic images. A final tomography image of the object is generated by using a spectrum signal based on an interference signal obtained by applying the selected pattern to an optical modulator, and the spatial light modulator is a light beam output from the light output unit, the measurement light beam, or the reference Modulates the phase of any one of the rays.

According to another aspect of the present invention, there is provided a computer-readable recording medium recording a program for executing a tomographic image generation method in a computer.

According to the above, in generating a tomography image of an object, by selecting a pattern that generates the clearest tomography image among a plurality of shift patterns obtained by performing spatial shift modulation on a basic pattern, the material characteristic of the object is determined. An optimal tomographic image with an increased transmission depth can be generated using a pattern reflecting the most suitable phase modulation amount.

1 is a block diagram illustrating an apparatus for generating a tomography image according to an embodiment of the present invention.
FIG. 2A is a diagram illustrating a shape in which light rays whose phase is not modulated by the spatial light modulator shown in FIG. 1 are transmitted through an object and focused.
FIG. 2B is a diagram illustrating a shape in which light rays that are phase-modulated by the spatial light modulator shown in FIG. 1 are transmitted through an object and focused.
3A is a diagram illustrating a plurality of shift patterns obtained by performing spatial shift modulation of a basic pattern in the modulation control unit shown in FIG. 1.
3B is a diagram illustrating an operation of acquiring a plurality of shift patterns by performing spatial shift modulation of a basic pattern in the modulation control unit shown in FIG. 1.
FIG. 4 is a diagram illustrating an operation of selecting phase-modulated spectrum images showing regular phase changes among the phase-modulated spectrum images generated by the image processing unit shown in FIG. 1.
5 is a diagram illustrating an optical coherence tomography apparatus corresponding to an embodiment of the tomography image generation apparatus illustrated in FIG. 1.
6 is a flowchart illustrating a tomography image generating method according to an embodiment of the present invention.
7 is a flowchart illustrating a tomography image generating method according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

1 is a block diagram illustrating an apparatus for generating a tomography image according to an embodiment of the present invention. Referring to FIG. 1, the tomography image generation apparatus 100 includes an optical output unit 110, a spatial light modulator 120, a modulation control unit 130, a detection unit 140, an image generation unit 150, and an image processing unit 160 ).

In the tomography image generating apparatus 100 illustrated in FIG. 1, only components related to the present embodiment are illustrated to prevent blurring of features of the present embodiment. Therefore, it can be understood by those of ordinary skill in the art related to this embodiment that components other than those illustrated in FIG. 1 may be further included.

The tomography image generating apparatus 100 according to the present embodiment is a device for acquiring a tomography image of an object using light, an optical coherence tomography (OCT), an optical coherent microscopy (OCM), It includes all optical imaging devices capable of acquiring tomographic images based on optical coherence, such as optical microscopes.

The light output unit 110 outputs light rays incident on the subject 10. At this time, the light output unit 110 may output wavelength-swept light, laser, and the like, but is not limited thereto. The light rays output from the light output unit 110 are incident on the object 10 through the spatial light modulator 120.

The spatial light modulator (SLM) 120 modulates the phase of a light beam according to a pattern in which pixels are arranged. In this case, the spatial light modulator 120 may be a digital micromirror device (DMD), but is not limited thereto. 2A and 2B for a detailed description related to phase modulation of the spatial light modulator 120.

The modulation control unit 130 determines at least one basic pattern of the spatial light modulator 120 and performs spatial shift modulation on the basic pattern to perform a plurality of shift patterns of the basic pattern ( shift patterns). The modulation control unit 130 controls the spatial light modulator 120 so that each of the obtained basic pattern and a plurality of shift patterns of the basic pattern are sequentially applied to the spatial light modulator 120.

The basic pattern represents a pattern that is a reference for performing spatial shift modulation. Spatial shift modulation acquires a shift pattern in which an arrangement of pixels is shifted by a predetermined number in a vertical or horizontal direction with respect to one basic pattern, and the modulation control unit 130 acquires a plurality of shift patterns with respect to one basic pattern can do. 3A and 3B for a detailed description related to spatial shift modulation of the modulation control unit 130.

The detector 140 detects a spectral signal for each of a plurality of shift patterns of the basic pattern and the basic pattern based on the rays obtained by the rays incident on the object 10 through the spatial light modulator 120. do. At this time, the rays obtained by the rays incident on the object 10 represent rays obtained by the phenomenon of transmission, reflection, scattering, etc. as the rays are incident on the object 10. For example, the acquired rays may be rays obtained by causing an interference phenomenon between a reference ray and a response ray obtained by measurement rays incident on the object 10. As another example, the acquired rays may be rays obtained by causing interference between the secondary harmonic signals of the response ray and the reference ray. However, it is not limited to this.

The image generating unit 150 generates a tomography image for each of a plurality of shift patterns of the basic pattern and the basic pattern using a spectral signal. For example, the modulation control unit 130 applies the basic pattern to the spatial light modulator 120, the detection unit 140 detects a spectrum signal for the applied basic pattern, and the image generating unit 150 spectrums of the basic pattern Generate a tomographic image of the signal. Next, the modulation control unit 130 applies the first shift pattern in which the basic pattern is spatially shift-modulated in the vertical or horizontal direction to the spatial light modulator 120, and the detection unit 140 receives the spectral signal for the first shift pattern. Upon detection, the image generator 150 generates a tomographic image of the first shift pattern spectrum signal. Similarly, the modulation control unit 130 obtains a plurality of shift patterns such as a second shift pattern and a third shift pattern in which the basic pattern is spatially shift-modulated by differently shifting the first shift pattern, the shift direction, and the shift amount, and image The generator 150 acquires tomography images for the second shift pattern, the third shift pattern, and the remaining shift patterns by using a spectrum signal obtained by sequentially applying a plurality of shift patterns.

The image processing unit 160 selects one pattern that generates the clearest tomographic image among each basic pattern and a plurality of shift patterns of the basic pattern. In this case, the clearest tomography image is a tomography image in which all rays incident on the object 10 are in phase, and when rays incident on the object 10 are in phase, rays of the same phase are Focusing on one point of the object 10, the energy of the light rays is maximized. Therefore, the clearest tomography image is a case where the energy of light is maximized in the obtained tomography image, and becomes the largest intensity of light among the obtained tomography images, that is, the brightest tomography image. The image processing unit 160 selects one pattern corresponding to the tomographic image selected as the clearest tomographic image among each basic pattern and a plurality of shift patterns of the basic pattern. At this time, the operation of determining the one pattern for generating the clearest tomography image by the image processing unit 160 may be automatically performed by a computer algorithm or the like.

The image processing unit 160 according to the present embodiment may correspond to at least one processor, or may include at least one processor. In addition, the image processing unit 160 may be located inside the tomography image generation apparatus 100 as illustrated in FIG. 1, but is not limited thereto, and may be located outside the tomography image generation apparatus 100.

The image generating unit 150 applies the pattern selected by the image processing unit 160 to the spatial light modulator 120 to generate a final tomographic image of the object 10 using the detected spectral signal.

According to an embodiment of the present invention, the tomography image generating apparatus 100 modulates the phase of each of the rays incident on the object 10 using a plurality of basic patterns to obtain a final tomography image optimized for the object 10 Can be created.

According to this, the modulation control unit 130 may determine a plurality of basic patterns for the object 10, and obtain a plurality of basic patterns for each of the plurality of basic patterns. In this case, the modulation control unit 130 may determine a plurality of basic patterns such that each of the plurality of basic patterns is in an uncorrelated relation to a phase change of a light beam according to spatial shift modulation of a different basic pattern. In one embodiment, the modulation control unit 130 may determine a plurality of basic patterns such that each of the plurality of basic patterns is orthogonal to each other with other basic patterns. Further, a plurality of basic patterns in an uncorrelated relationship may be determined based on permutation of a Hadamard pattern.

The modulation control unit 130 acquires a plurality of shift patterns of each basic pattern by performing spatial shift modulation on each of the plurality of basic patterns. The modulation control unit 130 spaces each of a plurality of basic patterns and a plurality of shift patterns of each basic pattern to generate a tomography image of each of the obtained plurality of basic patterns and a plurality of shift patterns of each basic pattern. It is applied to the light modulator 120 in turn. According to the pattern applied to the spatial light modulator 120, the image generator 150 generates tomographic images for each of a plurality of basic patterns and a plurality of shift patterns of each basic pattern.

The image processing unit 160 repeats the operation of selecting one pattern that generates the clearest tomographic image among each basic pattern and a plurality of shift patterns of the basic pattern for each of the plurality of basic patterns, and then selects a plurality of selected patterns Acquire them. At this time, the plurality of selected patterns corresponds to a set of patterns that optimally modulate the phase of the light beam incident on the object 10 according to the material characteristics of the object 10. In order to apply an optimal phase modulation amount corresponding to each basic pattern to each of the plurality of basic patterns to one pattern, the image processing unit 160 combines the plurality of selected patterns into a single weighting pattern. . At this time, in order to apply the weighted pattern to the spatial light modulator 120, the image processing unit 160 binarizes the weighted pattern based on a predetermined threshold and forms a finalized binary pattern. The image generating unit 150 generates a final tomography image of the object using the final pattern. The final tomography image corresponds to an optimized tomography image by modulating the phase according to the material characteristics of the object 10.

According to an embodiment of the present invention, the tomography image generating apparatus 100 may generate a final pattern using only some basic patterns showing regular phase changes among a plurality of basic patterns. The image processing unit 160 generates a single phase modulated spectrum image using spectral images of each basic pattern and a plurality of shift patterns of the basic pattern in order to select only some basic patterns showing regular phase changes.

According to this, the image generator 150 acquires a spectrum image for each of the basic pattern and a plurality of shift patterns of the basic pattern based on the spectrum signal. The image processing unit 160 arranges spectral images of a plurality of shift patterns of the corresponding basic pattern in a matrix form according to a shift direction and a shift amount of the spatial shift modulation based on the spectral images of each basic pattern, so that the phase of the light beam according to the spatial shift modulation It produces a single phase modulated spectrum image representing the change of. The image processing unit 160 acquires a plurality of phase-modulated spectrum images by repeating a task of generating one phase-modulated spectrum image for each of the plurality of basic patterns.

The image processing unit 160 uses only basic patterns of phase-modulated spectrum images showing a regular phase change among a plurality of phase-modulated spectrum images and shift patterns of each basic pattern to generate the final pattern. Accordingly, the image processing unit 160 is only the basic patterns of the phase-modulated spectrum images showing a regular phase change among the plurality of phase-modulated spectrum images, and each base pattern and the clearest single layer among the plurality of shift patterns of the base pattern Selecting one pattern for generating an image is performed. The image processing unit 160 performs a task of selecting only the basic patterns of phase modulated spectrum images showing regular phase changes, thereby generating a final pattern using only the obtained patterns.

At this time, the regular phase change is that the amount of phase change according to the spatial shift modulation changes with a certain regularity. For example, when the phase change appearing in the phase modulated spectrum image has sinusoidal characteristics, it can be determined to have a regular phase change. At this time, the operation of determining whether the corresponding phase-modulated spectrum image has a regular phase change by the image processing unit 160 may be automatically performed by a computer algorithm or the like.

According to an embodiment of the present invention, the tomography image generating apparatus 100 may further include a light control unit (not shown). The light control unit (not shown) determines a region of interest (ROI) corresponding to a transmission depth for focusing rays on the object 10 and controls the rays so that the rays are focused on the determined region of interest. The image generating unit 150 generates a final tomographic image using the obtained final pattern by performing operations for obtaining a final pattern having an optimal phase modulation amount with respect to the determined region of interest of the object 10.

The light controller (not shown) may determine a plurality of regions of interest having different transmission depths in which light rays are focused on the object 10. Accordingly, the light control unit (not shown) controls the rays so that the rays are sequentially focused on a plurality of regions of interest. The image generating unit 150 sequentially generates a final tomography image for a plurality of regions of interest of the object 10 to obtain a plurality of final tomography images. The image processing unit 160 generates a single edited tomography image by connecting a plurality of final tomography images. Accordingly, the tomography image generating apparatus 100 may combine the optimum tomography images optimized for each transmission depth, and obtain one final tomography image corresponding to the total transmission depth.

According to an embodiment, the light controller (not shown) determines the transmission depth of the object 10 to focus the light rays based on the intensity of the spectral signal according to the transmission depth of the object 10, and the determined transmission The region corresponding to the depth can be determined as the region of interest. For example, a tomography image may be generated using a spectral signal having the greatest intensity for each of the basic pattern and the plurality of shift patterns. As the depth of transmission of the object 10 increases, the intensity of the spectral signal gradually decreases. Accordingly. The tomography image generating apparatus 100 may generate a tomography image based on a spectrum signal having the greatest intensity, thereby acquiring a tomography image having a constant transmission depth. The operation of the optical control unit 160 to determine the transmission depth of the object 10 to focus the light rays based on the intensity of the spectral signal may be automatically performed by a computer algorithm or the like.

In addition, the light control unit (not shown) may horizontally move a position where light rays are incident on the object 10. The image generating unit 150 sequentially acquires a plurality of final tomographic images corresponding to each position of the moved rays as the positions of the incident rays move, and the image processing unit 160 connects the plurality of final tomographic images to the object In (10), one final tomography image of the region corresponding to the entire travel distance is generated. Accordingly, the tomography image generating apparatus 100 may combine the optimum tomography images optimized for the position moved by the light controller (not shown), and obtain one final tomography image corresponding to the entire horizontal movement distance.

FIG. 2A is a diagram illustrating a shape in which light rays whose phase is not modulated by the spatial light modulator shown in FIG. 1 are transmitted through an object and focused.

Referring to FIG. 2A, lines incident on the spatial light modulator 120 and focused inside the object 10 represent light rays output from the light output unit 110. The phase modulation amount of each ray is represented by Φ1, Φ2, and Φ3. The amount of phase modulation of the rays of FIG. 2A is 0, and the rays of FIG. 2A are rays whose phase is not modulated by the spatial light modulator 120. Light rays output from the light output unit 110 are incident on the object 10. At this time, the material properties of the object 10 to generate a tomography image are non-uniform and turbid. Accordingly, as the rays incident on the object 10 in the same phase pass through the object 10 and the phase of each of the rays is changed and focused, the rays cannot be in-phase at the point where the tomography image is to be obtained. The focused energy is also reduced compared to in-phase.

FIG. 2B is a diagram illustrating a shape in which light rays that are phase-modulated by the spatial light modulator shown in FIG. 1 are transmitted through an object and focused. As in FIG. 2A, lines incident on the spatial light modulator 120 of FIG. 2B and focused within the object 10 represent rays output from the light output unit 110, and the object 10 to generate a tomography image The material properties of are non-uniform and turbid.

The light rays of FIG. 2B are phase-modulated by the spatial light modulator 120 and transmitted to the object 10. The amount of phase modulation by the spatial light modulator 120 of each light ray in FIG. 2B is represented by Φ1 = 1.32, Φ2 = -2.1, and Φ3 = 0.71, respectively. The light rays of FIG. 2A are modulated differently in phase by the spatial light modulator 120 and transmitted to the object 10. The rays incident on the object 10 in different phases pass through the object 10 and become in-phase at a point where a tomography image is to be obtained, so that the focused energy of the rays is maximized.

In order to maximize the focusing energy of rays incident on the non-uniform and cloudy object 10, the tomography image generating apparatus 100 according to the present embodiment utilizes spatial shift modulation to modulate the amount of phase for each ray Can be controlled.

The tomography image generating apparatus 100 according to the present embodiment selects a pattern that generates a clearest tomography image among a plurality of shift patterns and a basic pattern of a basic pattern obtained by using spatial shift modulation, thereby corresponding object 10 An optimal tomography image may be generated using a pattern reflecting a phase modulation amount that is most suitable for the material properties of.

FIG. 3A is a diagram illustrating a plurality of shift patterns obtained by performing spatial shift modulation of a basic pattern in the modulation control unit shown in FIG. 1. The patterns shown in FIG. 3A represent shift patterns obtained by moving an array of pixels one by one in a horizontal direction based on one basic pattern.

The modulation control unit 130 determines the first basic pattern 310 and acquires a plurality of shift patterns 320, 330, and 340 by performing spatial shift modulation on the first basic pattern 310 in the horizontal direction. .

The first shift pattern is represented by B ₁ ¹ , and is shifted by 0 in the x-axis (horizontal direction) and 0 in the y-axis (vertical direction) based on B ¹ , which is the first basic pattern 310. It is the same as the basic pattern 310. The second shift pattern 320 of the first basic pattern 310 is denoted by B ₂ ¹ , and based on B ¹ , which is the first basic pattern 310, by ¹ in the x-axis (horizontal direction), the y-axis (vertical Direction). The third shift pattern 330 of the first basic pattern 310 is denoted by B ₃ ¹ , based on B ¹ , which is the first basic pattern 310, by 2 in the x-axis (horizontal direction), the y-axis (vertical Direction). The modulation control unit 130 of FIG. 3A acquires 10 shift patterns by performing 9 spatial shift modulations by 1 horizontally based on the first basic pattern 310. The 10th pattern 340, which is the last shift pattern of the first basic pattern 310, is represented by B ₁₀ ¹ , and 9 by x in the x-axis (horizontal direction), based on B ¹ , which is the first basic pattern 310, y It is moved by 0 in the axis (vertical direction).

The modulation control unit 120 may also perform spatial shift modulation in the vertical direction of the first basic pattern 310. The modulation control unit 120 modulates each of the basic pattern 310 and each of the 10 shift patterns spatially modulated in the horizontal direction by 9 spatial shift modulations in the vertical direction, and a total of 100 shifts including the basic pattern 310 Patterns can be obtained.

The modulation control unit 120 sequentially applies a total of 100 shift patterns to the spatial light modulator 120, and the image generation unit 150 may generate tomographic images for each of the shift patterns.

The tomography image generating apparatus 100 acquires a plurality of shift patterns by performing spatial shift modulation on other basic patterns other than the first basic pattern 310 as described above, and shift patterns of each basic pattern and the corresponding basic pattern Each of these may be applied to the spatial light modulator 120 to generate tomographic images.

3B is a diagram illustrating an operation of acquiring a plurality of shift patterns by performing spatial shift modulation of a basic pattern in the modulation control unit shown in FIG. 1. 3B, an arrangement of pixels of a pattern applied to the spatial light modulator 120 is shown. Hereinafter, for convenience of description, the spatial light modulator 120 of FIG. 3B will be described as being a digital micromirror device (DMD). The DMD is composed of micro-mirrors that reflect incident rays, and controls each micro-mirror on / off, and forms a pattern according to the arrangement of on / off pixels. Hereinafter, for convenience of description, it is assumed that black is on and white is off. However, the on / off color may be expressed in reverse.

The spatial light modulator 120 performs spatial shift modulation on a basic pattern by a predetermined number of pixels in a vertical or horizontal direction with respect to one basic pattern formed by an on / off arrangement of pixels in the spatial light modulator 120. Move the on / off array. In this embodiment, the spatial shift modulation is illustrated as moving one by one in the vertical direction with respect to the basic pattern, but is not limited thereto.

Referring to FIG. 3B, the pixels in the leftmost column in the on / off arrangement of the spatial light modulator 120 with respect to the first basic pattern 350 are all off, except for the fourth pixel from the top. Looking at the first shift pattern 360 spatially shift-modulated by 1 in the vertical direction with respect to the first basic pattern 350, the pixels in the leftmost column have been shifted to the fifth pixel from the on state. Looking at the fourth shift pattern 370 spatially modulated by 4 in the vertical direction with respect to the first basic pattern 350, the pixels in the leftmost column are moved to the third pixel from the top in the on state.

As described above, the modulation control unit 130 performs spatial shift modulation by controlling the on / off arrangement of pixels of the spatial light modulator 120 to be sequentially moved in the vertical or horizontal direction based on one basic pattern. can do.

FIG. 4 is a diagram illustrating an operation of selecting phase-modulated spectrum images showing regular phase changes among the phase-modulated spectrum images generated by the image processing unit shown in FIG. 1. The phase-modulated spectrum images shown in FIG. 4 are composed of spectral images of 100 shift patterns obtained by performing 99 spatial shift modulations on each basic pattern.

FIG. 4 shows only six spectral images, which are part of the phase-modulated spectrum images for a total of 10 basic patterns.

The image generating unit 150 obtains a spectrum image for each of the basic pattern and a plurality of shift patterns of the basic pattern based on the spectrum signal obtained by the detector 140. The image processing unit 160 arranges spectral images of a plurality of shift patterns of the corresponding basic pattern in a matrix form according to a shift direction and a shift amount of the spatial shift modulation based on the spectral images of each basic pattern, so that the phase of the light beam according to the spatial shift modulation It produces a single phase modulated spectrum image representing the change of. In each phase-modulated spectrum image of FIG. 4, spectrum images of 100 shift patterns are arranged in a matrix form according to a shift direction and a shift amount.

The phase-modulated spectrum image 410 for the first basic pattern (Basis1) shows a regular phase change according to spatial shift modulation. In particular, the phase modulated spectrum image 410 shows a phase change of sinusoidal characteristics. The phase modulation spectrum image 420 for the third basic pattern (Basis3) has less regular phase change than the phase modulation spectrum image 410, but the phase modulation spectrum images 440, 450, and 460 on the right side ), The phase change of sinusoidal characteristics is shown. The phase-modulated spectrum image 430 for the tenth basic pattern (Basis10) also shows a regular phase change according to spatial shift modulation.

On the other hand, the phase modulated spectrum image 440 for the second basic pattern (Basis2) shows an irregular phase change according to spatial shift modulation. Likewise, the phase shifts of the remaining phase modulated spectral images 450 and 460 are irregular due to spatial shift modulation, and sinusoidal characteristics do not appear.

Accordingly, the image processing unit 160 only the basic patterns of the phase-modulated spectrum images 410 to 430 showing regular phase changes among the plurality of phase-modulated spectrum images 410 to 460 and shift patterns of each basic pattern Used for generating the final pattern. That is, the modulation control unit 130 includes the first basic pattern, the third basic pattern, the tenth basic pattern, and each basic pattern of phase-modulated spectrum images 410 to 430 representing regular phase changes. Only 100 shift patterns of are applied to the spatial light modulator 120. Accordingly, the image generator 150 generates tomography images only for each of the first basic pattern, the third basic pattern, the tenth basic pattern, and each of the 100 shift patterns of each basic pattern. The image processing unit 160 selects one pattern that generates the clearest tomographic image among each basic pattern and a plurality of shift patterns of the basic pattern only for the first basic pattern, the third basic pattern, and the tenth basic pattern To perform.

As described above, the tomography image generating apparatus 100 uses only basic patterns of phase-modulated spectrum images showing regular phase changes and shift patterns of each basic pattern to generate the final pattern.

5 is a view showing an optical coherence tomography apparatus (Optical Coherence Tomography Apparatus) corresponding to an embodiment of the tomography image generating apparatus shown in FIG. 1. 5, the optical interference tomography apparatus 500 includes an optical output unit 510, a spatial light modulator 521, a modulation control unit 530, a detection unit 540, an image generation unit 550, and an image processing unit ( 560), an interferometer 570 and an optical probe 580. In FIG. 1, contents described in connection with the light output unit 110, the spatial light modulator 120, the modulation control unit 130, the detection unit 140, the image generation unit 150, and the image processing unit 160 are illustrated in FIG. 5. Since it can be applied to the optical output unit 510, the spatial light modulator 521, the modulation control unit 530, the detection unit 540, the image generation unit 550, and the image processing unit 560, a duplicate description in this regard Is omitted. Accordingly, it can be seen that even if omitted below, the contents described above with respect to the tomography image generating apparatus 100 illustrated in FIGS. 1 to 4 also apply to the optical interference tomography apparatus 500 illustrated in FIG. 5. .

In the optical interference tomography apparatus 500 illustrated in FIG. 5, only components related to the present embodiment are illustrated in order to prevent blurring of features of the present embodiment. Therefore, it can be understood by those of ordinary skill in the art related to the present embodiment that other general-purpose components may be further included in addition to the components shown in FIG. 5.

The light output unit 510 outputs light rays. At this time, the light rays output from the light output unit 510 may correspond to light or lasers having a variable wavelength, but are not limited thereto. The light output unit 510 transmits the output beams to the interferometer 570. According to an embodiment of the present invention, the spatial light modulator 120 may be located between the light output unit 510 and the interferometer 570. Accordingly, the phase-modulated light by the spatial light modulator 120 may be transmitted to the interferometer 570.

The spatial light modulator 521 modulates the phase of the light beam according to a pattern in which pixels are arranged. The spatial light modulator 521 of the optical coherence tomography apparatus 500 may modulate the phase of any one of a light beam, a measurement light beam, or a reference light beam emitted from the light output unit 110. Referring to FIG. 5, the spatial light modulator 521 of the optical coherence tomography apparatus 500 is not only the position between the light output unit 510 and the interferometer 570, but also the second position 522 or the third position It can also be located at (523). That is, the spatial light modulator 521 is a measurement light beam separated from the beam splitter 572, between the light output unit 510 and the interferometer 570, between the reference mirror 574 and the beam splitter 572 of the interferometer 570 It may be located at any one of the positions on the probe 580 side.

The modulation control unit 530 determines at least one basic pattern of the spatial light modulator 521 and performs spatial shift modulation to move an array of pixels by a predetermined number in a vertical or horizontal direction with respect to the basic pattern. A plurality of shift patterns are acquired, and the spatial light modulator 521 is controlled such that each of the basic pattern and the plurality of shift patterns of the basic pattern are sequentially applied to the spatial light modulator 521.

The interferometer 570 separates the light beams output from the light output unit 510 into a measurement light beam and a reference light beam, irradiates the measurement light beam to the object 10, and detects the response light beam reflected from the object 10 and returned. To receive.

The detector 540 detects an interference signal generated by the response beam and the reference beam, and detects a spectral signal for each of a plurality of shift patterns of the basic pattern and the basic pattern based on the interference signal. The detection unit 540 transmits the detected spectrum signal to the image generation unit 550.

The image generating unit 550 generates a tomographic image for each of a plurality of shift patterns of the basic pattern and the basic pattern using a spectrum signal.

The image processing unit 560 selects one pattern that generates the clearest tomographic image among the basic pattern and a plurality of shift patterns of the basic pattern based on the generated tomographic images. The image generator 560 generates a final tomography image of the object 10 using a spectrum signal based on the interference signal obtained by applying the selected pattern to the spatial light modulator 521.

The interferometer 570 may include a beam splitter 572 and a reference mirror 574. The beams transmitted from the light output unit 510 are separated into a measurement beam and a reference beam in the beam splitter 572. Among the light beams separated from the beam splitter 572, the measurement light beam is transmitted to the optical probe 580, the reference light beam is transmitted to the reference mirror 584 and reflected, and then back to the beam splitter 582. On the other hand, the measurement light beam transmitted to the optical probe 580 is irradiated to the object 10 to take an internal tomography image through the light probe 580, and the response light beam is irradiated from the object 10 Is transmitted to the beam splitter 572 of the interferometer 570 through the optical probe 580. The transmitted response beam and the reference beam reflected from the reference mirror 574 cause interference in the beam splitter 572.

The optical probe 580 may include a collimator lens 582, a galvano scanner 584 and a lens 586. Here, the galvano scanner 584 may be implemented as a MEMS scanner that obtains a driving force required for rotation from a microelectromechanical system (MEMS) as a mirror capable of rotating a certain radius around a certain axis. The measurement light transmitted from the interferometer 570 is collimated while passing through the collimator lens 582 of the optical probe 580, is reflected by the galvano scanner 584, the direction of travel is adjusted to pass through the lens 586, and then the object (10).

Accordingly, the optical interference tomography apparatus 500 selects a pattern that generates the clearest tomography image among the plurality of shift patterns of the basic pattern obtained by using spatial shift modulation, and determines the material characteristics of the object 10. A pattern reflecting the most suitable phase modulation amount may be acquired, and an optimal tomography image having an increased transmission depth may be generated using the acquired pattern.

6 is a flowchart illustrating a tomography image generating method according to an embodiment of the present invention. Referring to FIG. 6, the method described in FIG. 6 is composed of steps processed in time series in the tomography image generating apparatus 100 or the optical interference tomography apparatus 500 illustrated in FIGS. 1 to 5. Accordingly, it is understood that the contents described above with respect to the tomography image generating apparatus 100 or the optical interference tomography apparatus 500 shown in FIGS. You can.

In operation 610, the modulation control unit 130 determines at least one basic pattern of the spatial light modulator 120 that modulates the phase of the incident light beam according to a pattern in which pixels are arranged.

In operation 620, the modulation control unit 130 performs spatial shift modulation to move an array of pixels by a predetermined number in a vertical or horizontal direction with respect to the basic pattern to obtain a plurality of shift patterns of the basic pattern.

In operation 630, the image generating unit 150 uses a spectrum signal of rays obtained by rays incident on the object 10 through the spatial light modulator 120 and a plurality of shift patterns of the basic pattern and the basic pattern Generate tomographic images for each.

In operation 640, the image processor 160 selects one pattern that generates the clearest tomographic image among the basic pattern and a plurality of shift patterns of the basic pattern based on the generated tomographic images.

In operation 650, the image generating unit 150 generates a final tomography image of the object 10 using the selected pattern.

7 is a flowchart illustrating a tomography image generating method according to another embodiment of the present invention. Referring to FIG. 7, the method described in FIG. 7 is composed of steps processed in time series in the tomography image generating apparatus 100 or the optical interference tomography apparatus 500 illustrated in FIGS. 1 to 5. Accordingly, it is understood that the contents described above with respect to the tomography image generating apparatus 100 or the optical interference tomography apparatus 500 illustrated in FIGS. 1 to 5 are applied to the method described in FIG. 7 even if omitted below. You can.

In operation 710, the modulation control unit 130 determines a plurality of basic patterns of the spatial light modulator 120 that modulates the phase of the incident light beam according to a pattern in which pixels are arranged. The modulation control unit 130 obtains a plurality of shift patterns of each basic pattern by performing spatial shift modulation for shifting the arrangement of pixels by a predetermined number in a vertical or horizontal direction for each basic pattern.

At this time, each of the plurality of basic patterns for the object 10 has no correlation with the phase change of the light beam according to the spatial shift modulation of the other basic pattern. For example, the basic pattern B1, the basic pattern B2, and the basic pattern B100 each have an uncorrelated relationship, and do not influence each other on the phase change according to the spatial shift modulation performed for each basic pattern.

In operation 720, the image processing unit 160 uses a spectrum signal of rays obtained by rays incident on the object 10 passing through the spatial light modulator 120 and each of a plurality of shift patterns of the basic pattern and the basic pattern Generates tomographic images for. The image processor 160 selects one pattern that generates the clearest tomographic image among each basic pattern and a plurality of shift patterns of the basic pattern based on the generated tomographic images. The tomography image generating apparatus 100 repeats the operation of selecting one pattern for generating the clearest tomography image among each basic pattern and a plurality of shift patterns of the basic pattern for each of the plurality of basic patterns, thereby selecting a plurality of Acquire patterns.

In operation 730, the image processing unit 160 generates phase-modulated spectrum images for each basic pattern by using spectral images of each of the basic pattern and a plurality of shift patterns of the basic pattern, and regular among the phase-modulated spectrum images Phase-modulated spectral images showing phase changes are selected. The graph shown at 730 shows the phase change of the phase modulated spectrum image for each basic pattern. At this time, the regular phase change may indicate that the phase change has sinusoidal characteristics. Referring to 730, the phase change of the phase modulated spectrum images for B1, B3, and B100 shows sinusoidal characteristics. Accordingly, it can be used to generate a final pattern only for a plurality of shift patterns of B1, B3, and B100.

At this time, the image processing unit 140 may generate phase-modulated spectrum images in the following manner. The image generator 150 obtains a spectrum image for each of the basic pattern and a plurality of shift patterns of the basic pattern based on the spectrum signal. The image processing unit 160 arranges spectral images of a plurality of shift patterns of the corresponding basic pattern in a matrix form according to a shift direction and a shift amount of the spatial shift modulation based on the spectral images of each basic pattern, so that light rays according to spatial shift modulation Generates a single phase modulated spectrum image representing the change in phase. The image processor 160 performs a plurality of basic operations for acquiring a spectrum image for each of the basic pattern and a plurality of shift patterns of the basic pattern, and generating a single phase modulated spectrum image using the acquired spectrum images. A plurality of phase modulated spectral images are obtained by repeating each of the patterns.

According to an embodiment, in operation 720, the operation of selecting one pattern that generates the clearest tomographic image among each basic pattern performed by the image processing unit 160 and a plurality of shift patterns of the basic pattern is performed in operation 720. It is not performed in advance, but may be performed only on basic patterns of phase modulated spectrum images showing regular phase changes among a plurality of phase modulated spectrum images. Referring to 740, one pattern for generating the clearest tomography images for B1, B3, and B100 is B ₄ ¹ , B ₅ ³ , B ₁₀ ¹⁰⁰ .

In operation 740, the image processing unit 160 combines the plurality of selected patterns into a single weighting pattern. Referring to FIG. 7, only the patterns of B ₄ ¹ , B ₅ ³ , and B ₁₀ ¹⁰⁰ are combined to generate one weighted pattern.

In operation 750, the image processing unit 160 forms a final pattern binarized based on a predetermined threshold value for the weighted pattern.

In operation 760, the image generation unit 150 generates a final tomography image of the object 10 using the final pattern.

Using the tomography image generation method described above, it is possible to generate an optimal tomography image having an increased transmission depth reflecting a phase modulation amount that is most suitable for a material characteristic of a corresponding object.

Meanwhile, the above-described method may be implemented as a program executable on a computer, and may be implemented on a general-purpose digital computer that operates the program using a computer-readable recording medium. In addition, the structure of data used in the above-described method may be recorded on a computer-readable recording medium through various means. The computer-readable recording medium includes a storage medium such as a magnetic storage medium (eg, ROM, floppy disk, hard disk, etc.), an optical reading medium (eg, CD-ROM, DVD, etc.).

Those of ordinary skill in the art related to the present embodiment will understand that it may be implemented in a modified form without departing from the essential characteristics of the above-described substrate. Therefore, the disclosed methods should be considered in terms of explanation, not limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent range should be interpreted as being included in the present invention.

100 ... tomography image generation device
110 ... light output
120 ... spatial light modulator
130 ... modulation control
140 ... detector
150 ... video generator
160 ... image processing unit

Claims (23)

In the method of generating a tomography image,
Determining a plurality of basic patterns of a spatial light modulator that modulates a phase of an incident light beam according to a pattern in which pixels are arranged;
Obtaining a plurality of shift patterns for each of the plurality of basic patterns by performing spatial shift modulation for shifting an arrangement of pixels by a predetermined number in a vertical or horizontal direction for each of the plurality of basic patterns;
Generating tomographic images for each of the plurality of basic patterns and the plurality of shift patterns using spectral signals of rays obtained by rays incident on an object passing through the spatial light modulator;
Selecting one pattern generating the clearest tomography image among the plurality of basic patterns and the plurality of shift patterns based on the generated tomography images;
Acquiring a plurality of selected patterns by repeating the step of selecting one pattern generating the clearest tomography image among the plurality of shift patterns for each of the plurality of basic patterns;
Summing the plurality of selected patterns into a single weighting pattern;
Generating a finalized binary pattern based on a predetermined threshold value for the weighted pattern; And
And generating a final tomography image of the object using the generated final pattern.
According to claim 1,
Each of the plurality of basic patterns has a non-correlated relationship with respect to a phase change of a light beam according to spatial shift modulation of another basic pattern.
delete According to claim 1,
Further comprising the step of determining the region of interest (ROI) corresponding to the transmission depth to focus the light rays in the object;
A tomography image generating method, characterized in that the steps of the tomography image generation method are repeated for the region of interest to generate a final tomography image for the region of interest. According to claim 1,
The method further includes determining a plurality of regions of interest having different transmission depths in which light rays are focused in the object.
By repeating the steps of the tomography image generation method for each of the plurality of regions of interest, a plurality of final tomography images for the plurality of regions of interest are generated, and the edited tomography images are generated by combining the plurality of final tomography images. Method of generating a tomography image, characterized in that. The method of claim 4,
The step of determining the region of interest
The transmission depth of the object to focus light rays is determined based on the intensity of the spectral signal according to the transmission depth of the object, and a region corresponding to the determined transmission depth is determined as the region of interest. Tomography image generation method. According to claim 1,
Obtaining spectral images for each of the plurality of basic patterns and a plurality of shift patterns for each of the plurality of basic patterns based on the spectrum signal; And
Spectral images of the plurality of shift patterns for each of the plurality of basic patterns are arranged in a matrix form according to a shift direction and a shift amount of the spatial shift modulation based on a spectrum image of each of the plurality of basic patterns, so that the spatial shift modulation is performed. Further comprising the step of generating a single phase modulated spectrum image representing a change in phase of the light beam according to,
Acquiring the spectral image and generating the one phase-modulated spectrum image for each of the plurality of basic patterns to obtain a plurality of phase-modulated spectrum images,
Generating the final pattern by performing a step of selecting one pattern for generating the clearest tomographic image only for basic patterns of phase-modulated spectrum images showing regular phase changes among the plurality of phase-modulated spectrum images Characterized by tomography image generation method.
The method of claim 7,
The regular phase change is a tomographic image generating method characterized in that the phase change has sinusoidal characteristics. According to claim 1,
Repeating the steps of the tomography image generation methods while horizontally moving the position where the light rays are incident on the object, obtains a plurality of final tomography images, and corresponds to the total movement distance in the object using the plurality of final tomography images A tomography image generating method characterized in that one final tomography image of the region is generated. According to claim 1,
The spatial light modulator is a digital micromirror device (DMD), characterized in that the tomography image generation method. According to claim 2,
The plurality of basic patterns are determined based on permutation of a Hadamard pattern. According to claim 1,
The tomography image generation method is a tomography image generation method characterized in that it is performed by an optical coherent tomography (OCT) or an optical coherent microscopy (OCM). A computer-readable recording medium recording a program for executing a tomographic image generating method of any one of claims 1, 2, 4 to 12 in a computer. In the tomography image generating apparatus,
A light output unit that emits light rays;
A spatial light modulator for modulating the phase of a light beam according to a pattern in which pixels are arranged;
Determining a plurality of basic patterns of the spatial light modulator, and performing spatial shift modulation to move an array of pixels by a predetermined number in a vertical or horizontal direction with respect to each of the plurality of basic patterns, relating to each of the plurality of basic patterns A modulation control unit that acquires a plurality of shift patterns and controls the spatial light modulator such that each of the plurality of basic patterns and the plurality of shift patterns is sequentially applied to the spatial light modulator;
A detector configured to detect a spectral signal for each of the plurality of basic patterns and the plurality of shift patterns based on rays obtained by rays incident on an object passing through the spatial light modulator;
An image generator that generates tomographic images for each of the plurality of basic patterns and the plurality of shift patterns using the spectrum signal; And
The plurality of basic patterns are selected based on the generated tomographic images to select one pattern that generates the clearest tomographic image among the plurality of basic patterns and the plurality of shift patterns for each of the plurality of basic patterns. By repeatedly performing for each, a plurality of selected patterns are obtained, the plurality of selected patterns are combined into one weighting pattern, and the weighted pattern is binarized based on a predetermined threshold value. Includes; image processing unit for generating a final pattern,
The image generation unit generates a tomography image of the object using the generated final pattern.
The method of claim 14,
Each of the plurality of basic patterns is a tomography image generating apparatus characterized in that it has no correlation with the phase change of the light beam according to the spatial shift modulation of the other basic pattern.
delete The method of claim 14,
Further comprising a light control unit for determining a region of interest (ROI) corresponding to the transmission depth to focus the rays on the object, and controlling the rays so that the rays are focused on the determined region of interest;
The tomography image generating unit, characterized in that for generating the final tomography image for the region of interest of the object. The method of claim 14,
Further comprising a light control unit for determining a region of interest (ROI) corresponding to the transmission depth to focus the rays on the object, and controlling the rays so that the rays are focused on the determined region of interest;
The light controller determines a plurality of regions of interest having different transmission depths at which the rays are focused in the object, and controls the rays so that the rays are sequentially focused on the regions of interest,
The image generating unit sequentially generates the final tomography images for the plurality of regions of interest of the object to obtain a plurality of final tomography images,
The image processor generates a tomographic image edited by combining the plurality of final tomographic images. The method of claim 17,
The light control unit determines a transmission depth of the object to focus light rays based on the intensity of the spectrum signal according to the transmission depth of the object, and determines a region corresponding to the determined transmission depth as the region of interest A tomography image generating apparatus, characterized in that. The method of claim 14,
The image generator acquires a spectrum image for each of the plurality of basic patterns and each of the plurality of shift patterns for each of the plurality of basic patterns based on the spectrum signal,
The image processing unit arranges spectrum images of the plurality of shift patterns for each of the plurality of basic patterns in a matrix form according to a shift direction and a shift amount of the spatial shift modulation based on a spectrum image for each of the plurality of basic patterns To generate a single phase modulated spectrum image representing a change in phase of the light beam according to the spatial shift modulation,
The image processor repeats the operation of generating the one phase modulated spectrum image for each of the plurality of basic patterns to obtain a plurality of phase modulated spectrum images, and regular phase changes among the plurality of phase modulated spectrum images Generating a tomography image, characterized in that only the basic patterns of the phase-modulated spectral images showing a single pattern generating the clearest tomography image among each basic pattern and a plurality of shift patterns of the basic pattern are performed. Device.
The method of claim 20,
The regular phase change is a tomography image generating apparatus characterized in that the phase change has sinusoidal characteristics. The method of claim 14,
Further comprising a light control unit for determining a region of interest (ROI) corresponding to the transmission depth to focus the rays on the object, and controlling the rays so that the rays are focused on the determined region of interest;
The light control unit horizontally moves a position where light rays are incident on the object,
The image generation unit sequentially acquires a plurality of final tomography images corresponding to each location of the moved rays as the positions of the incident rays move,
The image processing unit generates a final tomography image of the region corresponding to the entire distance of movement from the object using the plurality of final tomography images. In the optical interference tomography apparatus,
A light output unit that emits light rays;
A spatial light modulator for modulating the phase of a light beam according to a pattern in which pixels are arranged;
Determining a plurality of basic patterns of the spatial light modulator, and performing spatial shift modulation to move an array of pixels by a predetermined number in a vertical or horizontal direction with respect to each of the plurality of basic patterns, relating to each of the plurality of basic patterns A modulation control unit that acquires a plurality of shift patterns and controls the spatial light modulator such that each of the plurality of basic patterns and the plurality of shift patterns is sequentially applied to the spatial light modulator;
An interferometer that separates the light beams output from the light output unit into a measurement light beam and a reference light beam, irradiates the measurement light beam to an object, and receives a response light beam reflected from the object and returned;
A detection unit detecting an interference signal generated by the response light beam and the reference light beam, and detecting a spectral signal for each of the plurality of basic patterns and the plurality of shift patterns based on the interference signal;
An image generator that generates tomographic images for each of the plurality of basic patterns and the plurality of shift patterns using the spectrum signal; And
The plurality of basic patterns are selected based on the generated tomographic images to select one pattern that generates the clearest tomographic image among the plurality of basic patterns and the plurality of shift patterns for each of the plurality of basic patterns. By repeatedly performing for each, a plurality of selected patterns are obtained, the plurality of selected patterns are combined into one weighting pattern, and the weighted pattern is binarized based on a predetermined threshold value. Includes; image processing unit for generating a final pattern,
The image generating unit generates a final tomography image of the object using the generated final pattern,
The spatial light modulator modulates the phase of any one of the light beams output from the light output unit, the measurement light beam, or the reference light beam.

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