3D optical imaging system and method

Abstract

The present invention relates to the technical field of life science and medical imaging devices, and in particular, to a 3D optical imaging system and method. The method comprises the following steps: S1, using a CCD camera to acquire a two-dimensional bio-optical image of an imaging target; S2, using the CCD camera in step S1 in combination with structured light to acquire a three-dimensional surface contour image of the imaging target; S3, registering the two-dimensional bio-optical image obtained in step S1 with the three-dimensional surface contour image obtained in step S2; and S4, performing reconstruction to obtain a three-dimensional bio-optical image. By means of using the same CCD camera to acquire the two-dimensional bio-optical image and the three-dimensional surface contour image of the imaging target, registering the two-dimensional bio-optical image with the three-dimensional surface contour image, using biological tissues with different optical properties to fill the three-dimensional surface contour image, and then combining the registered data, the three-dimensional bio-optical image can be obtained, thereby achieving the three-dimensional space distribution of bio-optical signals in the organism.

Description

A 3D optical imaging system and method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application filed on December 7, 2023, with application number 202311668083.7, entitled “A 3D Optical Imaging System and Method,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the technical field of life science and medical imaging equipment, and in particular to a 3D optical imaging system and method. Background Art

[0004] Bio-optical imaging is widely used due to its mature instrumentation, high sensitivity, high contrast, high resolution, intuitive imaging, fast imaging speed, and non-destructive detection. It holds important practical significance and promising applications in exploring disease pathogenesis, clinical manifestations, genetic lesions, understanding corresponding physiological and pathological information, disease diagnosis, and the development of new medical treatments.

[0005] Bio-optical imaging, which uses optical detection combined with chemiluminescence or fluorescence to image molecules, cells, tissues, and organisms, is an important method for obtaining biological information. Depending on the detection method, bio-optical imaging can be divided into molecular fluorescence imaging, bioluminescence imaging, photoacoustic imaging, and optical tomography.

[0006] Structured light imaging projects a specific structured light pattern (such as stripes or grids) onto the surface of the object being imaged. A camera then uses the data to record the deformation of the structured light on the surface, thereby inferring the 3D shape of the object. Structured light imaging typically consists of three main components: a projection system, a camera, and a computer processing system. The projection system typically illuminates the object being measured by projecting a grating or stripe pattern. The shape and size of these gratings or stripes can be adjusted as needed. The camera records the structured light pattern on the surface of the object being measured and converts it into a digital image. The camera's resolution and acquisition speed significantly impact imaging accuracy and real-time performance. The computer processing system processes the captured image data and reconstructs the 3D shape of the object being measured based on the structured light deformation information. This process typically includes steps such as image preprocessing, camera calibration, 3D reconstruction, and data visualization. Structured light imaging technology offers the advantages of being non-contact, highly precise, and efficient, and is widely used in industrial manufacturing, medical imaging, cultural heritage conservation, and virtual reality.

[0007] Current bio-optical imaging systems use bio-optical imaging to image cells, tissues, and even organisms to obtain biological information. However, this mainly involves two-dimensional surface imaging, making it difficult to obtain the three-dimensional distribution of bio-optical signals inside organisms.

[0008] Therefore, there is an urgent need to provide a 3D optical imaging system and method that can realize the three-dimensional spatial distribution of bio-optical signals in vivo compared to the existing technology.

[0009] Summary of the Invention

[0010] The present invention solves the technical problems existing in the prior art and provides a 3D optical imaging system and method.

[0011] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0012] A 3D optical imaging method comprises the following steps:

[0013] S1. Acquire a two-dimensional bio-optical image of an imaging target by using a CCD camera, wherein the two-dimensional bio-optical image is a bioluminescence image or a molecular fluorescence image;

[0014] S2, acquiring a three-dimensional surface contour image of the imaging target by using the CCD camera described in step S1 in combination with structured light;

[0015] S3, registering the two-dimensional bio-optical image obtained in step S1 with the three-dimensional surface contour image obtained in step S2;

[0016] S4. The acquired three-dimensional surface contour image is filled with biological tissues with different optical properties to obtain a three-dimensional solid structure, and then combined with the data obtained after alignment based on step S3, a three-dimensional bioluminescence image or a three-dimensional molecular fluorescence image is reconstructed in three dimensions.

[0017] Furthermore, S2 specifically includes the following steps:

[0018] S201, turning on the projector, projecting the modulated stripe pattern structured light onto the imaging target surface, and using a CCD camera to capture the stripes on the imaging target surface;

[0019] S202, processing the fringes to obtain a phase distribution map of the imaging target surface;

[0020] S203, obtaining a geometrically calibrated phase-coordinate relationship, and using the geometrically calibrated phase-coordinate relationship to convert the phase distribution into three-dimensional coordinates;

[0021] S204, adjusting the angle between the imaging bracket and the imaging system, and repeating steps S201-S203;

[0022] S205 , obtaining multi-angle three-dimensional coordinates of the imaging target by adjusting the angle, thereby obtaining a three-dimensional surface contour image of the imaging target.

[0023] Furthermore, the phase distribution map of the imaging target surface is obtained by the following method: each image taken contains fringe images of different phases, and the wrapped phase distribution of the fringe is obtained by performing algebraic operations and splicing operations on the fringe images. Then, according to the spatial order information of the fringe, the wrapped phase is spatially phase unfolded to obtain the phase distribution map of the imaging target surface.

[0024] Furthermore, the geometric calibration method of the phase-coordinate relationship is: given the phase and CCD camera image coordinates, the CCD camera image coordinates are converted into three-dimensional coordinates of the CCD camera coordinate system through the camera parameters, and then the three-dimensional coordinates of the CCD camera coordinate system are converted into three-dimensional coordinates of the projector coordinate system according to the relative parameters of the projector and the CCD camera, and then the three-dimensional coordinates of the projector coordinate system are converted into projector image coordinates according to the projector parameters. Because the phase and the projector image coordinates correspond one to one, the phase-coordinate relationship is obtained.

[0025] Furthermore, the method for acquiring a molecular fluorescence image is as follows: turning on an excitation light source, emitting a laser from the excitation light source to illuminate an imaging target, thereby exciting the fluorescent molecules carried by the imaging object to generate emitted fluorescence; the generated emitted fluorescence is reflected by a reflector and a filter, or the generated emitted fluorescence is not reflected but only passes through a filter, and is then collected and processed by a CCD camera to obtain a two-dimensional biological optical image.

[0026] Furthermore, the method for acquiring a bioluminescent image is as follows: a chemical reaction occurs inside the imaging object, releasing a bioluminescent signal, and the emitted bioluminescent signal passes through a reflector and a filter, and is then collected and processed by a CCD camera to obtain a two-dimensional biological image; or, the generated bioluminescence is not reflected, but only passes through a filter, and is then collected and processed by a CCD camera to obtain a two-dimensional bio-optical image; or, the generated bioluminescence is neither reflected nor needs to pass through a filter, and is directly collected and processed by a CCD camera to obtain a two-dimensional bio-optical image.

[0027] Furthermore, the data obtained in step S4 based on the registration in step S3 includes the correspondence between each point on the two-dimensional bio-optical image and the point on the three-dimensional surface contour image and the corresponding optical signal intensity.

[0028] A 3D optical imaging system employing the above-mentioned 3D optical imaging method comprises an imaging support and an imaging system, wherein the imaging system comprises an excitation light source and a CCD camera; an imaging target is fixed to the imaging support, and the excitation light source and the CCD camera are arranged on the same side of the imaging target or on both sides of the imaging target;

[0029] A projector is provided on one side of the imaging target.

[0030] Furthermore, a reflector is provided between the imaging target and the CCD camera, and a projector is provided on one side of the reflector.

[0031] Furthermore, a filter is provided between the reflector and the CCD camera.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention uses the same CCD camera to obtain a two-dimensional bio-optical image and a three-dimensional surface contour image of the imaging target, then aligns the two-dimensional bio-optical image and the three-dimensional surface contour image, uses biological tissues with different optical properties to fill the three-dimensional surface contour image, and then combines the aligned data to obtain a three-dimensional bio-optical image, thereby realizing the three-dimensional spatial distribution of bio-optical signals in the organism. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a structural diagram of the system of the present invention.

[0035] FIG2 is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] As shown in Figure 1, the present invention provides a 3D optical imaging system comprising an imaging support and an imaging system. The imaging system includes an excitation light source and a CCD camera. The imaging support utilizes a stage or an imaging bed, and is used to secure an imaging target. The imaging target can be secured to the imaging support vertically or horizontally. The excitation light source and the CCD camera are disposed on the same side of the imaging support or on opposite sides of the imaging support. The excitation light source may be a laser source, an LED light source, a halogen lamp, or the like. This application does not specifically limit the type of excitation light source.

[0038] In this embodiment, the excitation light source is arranged on the right side of the imaging target, and a reflector is provided between the imaging target and the CCD camera (the reflector can also be omitted and the CCD camera can be used directly for acquisition). The excitation light source, imaging target and reflector are arranged in sequence along the irradiation direction of the excitation light source, the CCD camera is arranged above the reflector, and a filter is provided between the CCD camera and the reflector.

[0039] A projector is also provided on one side of the reflector; the angle between the imaging bracket and the imaging system can be rotated and adjusted, and the excitation light source and the projector are both aimed at the imaging target fixed on the imaging bracket. The light emitted by the excitation light source and the projector is irradiated on the imaging target, and the fluorescence excited by the excitation light source and the emitted light of the projector reflected by the imaging object are both reflected by the reflector and collected by the CCD camera.

[0040] As shown in FIG2 , the present invention further provides a 3D optical imaging method, comprising the following steps:

[0041] S1. Acquire a two-dimensional bio-optical image of the imaging target. The two-dimensional bio-optical image includes two modalities: bioluminescence image and molecular fluorescence image. In this step, only one of the bioluminescence image and the molecular fluorescence image is required.

[0042] Specifically, the method for acquiring bioluminescent images is as follows: utilizing a chemical reaction inside the imaging object to release a bioluminescent signal, and the emitted bioluminescent signal passes through a reflector and a filter, and is then collected and processed by a CCD camera to obtain a two-dimensional biological image; or, the generated bioluminescence is not reflected, but only passes through a filter, and is then collected and processed by a CCD camera to obtain a two-dimensional bio-optical image; or, the generated bioluminescence is neither reflected nor needs to pass through a filter, and is directly collected and processed by a CCD camera to obtain a two-dimensional bio-optical image.

[0043] The chemical reactions within the imaged object are enzymatic reactions within the organism, resulting in autofluorescence within the animal body. The enzyme that catalyzes this reaction is called luciferase. A common approach involves constructing an expression vector for the luciferase gene, transfecting target cells, and then transplanting them into the recipient's target organ. During observation, exogenous luciferin is injected, causing a reaction within the target cells to produce fluorescence. Highly sensitive in vivo bio-optical imaging systems can then be used to monitor the expression of target cells or molecules in real time.

[0044] The method for acquiring molecular fluorescence images is as follows: turning on the excitation light source, the excitation light source emits laser to illuminate the imaging target, exciting the fluorescent molecules carried by the imaging object to generate emitted fluorescence; the generated emitted fluorescence is reflected by the reflector and the filter, or the generated emitted fluorescence is not reflected but only passes through the filter, and is then collected and processed by the CCD camera to obtain a two-dimensional bio-optical image.

[0045] S2. Acquiring a three-dimensional surface contour image of the imaging target: specifically comprising the following steps:

[0046] S201, turning on the projector, projecting the modulated stripe pattern structured light onto the imaging target surface, and using a CCD camera to capture the stripes on the imaging target surface;

[0047] S202: The fringes are then processed. Each captured image contains fringe images with different phases. By performing algebraic operations and splicing operations on the fringe images, the wrapped phase distribution of the fringes can be obtained. Then, based on the spatial order information of the fringes, the wrapped phase is spatially phase-unwrapped to obtain a phase distribution map of the imaging target surface.

[0048] S203, obtaining a geometrically calibrated phase-coordinate relationship, and using the geometrically calibrated phase-coordinate relationship to convert the phase distribution into three-dimensional coordinates;

[0049] The method for obtaining the phase-coordinate relationship is as follows: geometric calibration includes camera calibration, projector calibration and joint calibration, which respectively obtains the internal parameters and distortion parameters of the CCD camera and projector, as well as the relative geometric parameters of the two. The three sets of parameters, camera parameters, projector parameters and relative geometric parameters, constitute the phase-coordinate relationship. Specifically, the phase corresponds to the projector image coordinates one-to-one, the projector image coordinates can be converted into the three-dimensional coordinates of the projector coordinate system through the projector parameters, and the three-dimensional coordinates of the projector coordinate system can be converted into the three-dimensional coordinates of the CCD camera coordinate system through the relative parameters. At the same time, the image coordinates captured by the CCD camera can be converted into the three-dimensional coordinates of the CCD camera coordinate system through the camera parameters. Therefore, the three-dimensional coordinates of the CCD camera coordinate system can be calculated when the phase and CCD camera image coordinates are known. This is the phase-coordinate relationship.

[0050] S204, adjusting the angle between the imaging bracket and the imaging system, and repeating steps S201-S203;

[0051] S205 , obtaining multi-angle three-dimensional coordinates of the imaging target by adjusting the angle, thereby obtaining a three-dimensional surface contour image of the imaging target.

[0052] S3. Align the two-dimensional bio-optical image obtained in step S1 with the three-dimensional surface contour image obtained in step S2. The specific alignment method is: the camera parameters have been obtained in the previous geometric calibration stage. The camera parameters can be used to convert the CCD camera image coordinates into three-dimensional coordinates of the CCD camera coordinate system, that is, use the camera parameters to back-project each point on the CCD camera image (here refers to the two-dimensional bioluminescence image) onto the three-dimensional surface contour, thereby completing the alignment of the two-dimensional bio-optical image and the three-dimensional surface contour image.

[0053] Specifically, since the two-dimensional bio-optical image and the three-dimensional surface profile image are both captured using the same CCD camera, the registration is performed based on the CCD camera parameters.

[0054] S4. Reconstruct three-dimensional bio-optical images: The acquired three-dimensional surface contour image is filled with biological tissues with different optical properties to obtain a three-dimensional solid structure. Combined with the data obtained after alignment in step S2, that is, the correspondence between each point on the two-dimensional bio-optical image and the point on the three-dimensional surface contour image and the corresponding optical signal intensity, a three-dimensional bioluminescence image (BLT) or a three-dimensional molecular fluorescence image (FMT) can be reconstructed in three dimensions.

[0055] The present invention uses the same CCD camera to acquire biological optical images and three-dimensional surface contour images. Laser and structured light perform optical imaging operations on the imaging target respectively. After alignment and reconstruction, a three-dimensional luminescent image or a three-dimensional molecular fluorescence image of the imaging target can be generated, which can simultaneously provide the molecular optical information inside the imaging target and the external three-dimensional spatial characteristics.

[0056] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A 3D optical imaging method, characterized in that: The following steps are involved: S1. Acquire a two-dimensional bio-optical image of an imaging target by using a CCD camera, wherein the two-dimensional bio-optical image is a bioluminescence image or a molecular fluorescence image; S2, using the CCD camera described in step S1 in combination with structured light to obtain a three-dimensional surface contour image of the imaging target; specifically comprising the following steps: S201, turning on the projector, projecting the modulated stripe pattern structured light onto the imaging target surface, and using a CCD camera to photograph the stripes on the imaging target surface; S202, processing the fringes to obtain a phase distribution diagram of the imaging target surface; S203, obtaining a phase-coordinate relationship after geometric calibration, and using the phase-coordinate relationship obtained after geometric calibration to convert the phase distribution into three-dimensional coordinates; S204, adjusting the angle between the imaging support and the imaging system, and repeating steps S201-S203; S205, obtaining multi-angle three-dimensional coordinates of the imaging target by adjusting the angle, thereby obtaining a three-dimensional surface contour image of the imaging target; The geometric calibration method of the phase-coordinate relationship is: given the phase and CCD camera image coordinates, the CCD camera image coordinates are converted into three-dimensional coordinates of the CCD camera coordinate system through the camera parameters, and then the three-dimensional coordinates of the CCD camera coordinate system are converted into three-dimensional coordinates of the projector coordinate system according to the relative parameters of the projector and the CCD camera, and then the three-dimensional coordinates of the projector coordinate system are converted into projector image coordinates according to the projector parameters. Since the phase corresponds to the projector image coordinates one by one, the phase-coordinate relationship is obtained; S3, registering the two-dimensional bio-optical image obtained in step S1 with the three-dimensional surface contour image obtained in step S2; S4, the acquired three-dimensional surface contour image is filled with biological tissues with different optical properties to obtain a three-dimensional solid structure, and then combined with the data obtained after the registration based on step S3, a three-dimensional bioluminescence image or a three-dimensional molecular fluorescence image is three-dimensionally reconstructed; The two-dimensional bio-optical image of the imaging target obtained in step S1 and the three-dimensional surface contour image of the imaging target obtained in step S2 are acquired through the same CCD camera.

2. A 3D optical imaging method according to claim 1, characterized in that: The phase distribution diagram of the imaging target surface is obtained by the following method: each captured image contains fringe images with different phases. The wrapped phase distribution of the fringe is obtained by performing algebraic operations and splicing operations on the fringe images. Then, according to the spatial order information of the fringe, the wrapped phase is spatially phase unfolded to obtain the phase distribution diagram of the imaging target surface.

3. A 3D optical imaging method according to claim 1, characterized in that: The method for acquiring a molecular fluorescence image is as follows: turning on an excitation light source, which emits a laser to illuminate an imaging target, thereby exciting the fluorescent molecules carried by the imaging object to generate emission fluorescence; the generated emission fluorescence is reflected by a reflector and a filter, or the generated emission fluorescence is not reflected but only passes through a filter, and then is collected and processed by a CCD camera to obtain a two-dimensional bio-optical image.

4. A 3D optical imaging method according to claim 1, characterized in that: The method for acquiring a bioluminescent image is as follows: a chemical reaction occurs inside the imaging object to release a bioluminescent signal, which passes through a reflector and a filter, and is then collected and processed by a CCD camera to obtain a two-dimensional biological image; or, the generated bioluminescence is not reflected, but only passes through a filter, and is then collected and processed by a CCD camera to obtain a two-dimensional bio-optical image; or, the generated bioluminescence is neither reflected nor needs to pass through a filter, and is directly collected and processed by a CCD camera to obtain a two-dimensional bio-optical image.

5. A 3D optical imaging method according to claim 1, characterized in that: The data obtained in step S4 after the registration based on step S3 includes the correspondence between each point on the two-dimensional bio-optical image and the point on the three-dimensional surface contour image and the corresponding optical signal intensity.

6. A 3D optical imaging system, characterized in that: A 3D optical imaging method according to any one of claims 1 to 5, characterized in that the system comprises an imaging support and an imaging system, the imaging system comprises an excitation light source and a CCD camera, an imaging target is fixed on the imaging support, and the excitation light source and the CCD camera are arranged on the same side of the imaging target or on both sides of the imaging target respectively; A projector is provided on one side of the imaging target.

7. A 3D optical imaging system according to claim 6, characterized in that: A reflector is arranged between the imaging target and the CCD camera, and a projector is arranged on one side of the reflector.

8. A 3D optical imaging system according to claim 7, characterized in that: A filter is arranged between the reflector and the CCD camera.

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