Blood flow laser speckle imaging method and device, storage medium and electronic equipment

Abstract

According to the method, the laser is controlled to approach the initial dynamic region from the outer edge of the initial dynamic region and movably irradiate the initial dynamic region to form a plurality of laser speckle sub-images until speckle fluctuation suddenly changes, so that the image A and the image B are determined. Wherein the irradiation area B corresponding to the front end of the image B in the laser moving direction and the irradiation area A corresponding to the abrupt change area of the image A have an overlapping area. In this way, the boundary of the blood flow can be determined by analyzing and comparing the image A and the image B. The blood flow boundary determined by the method is located within a false boundary determined by the false dynamic region, i.e. Closer to the real blood flow boundary than the false boundary, because there is an overlap between the irradiation region B and the irradiation region A. Therefore, the dynamic region and the static region of the image are divided by the boundary determined by the method, so that the false dynamic region in the image can be effectively reduced to realize effective denoising, and the quality of the finally obtained blood speckle image is improved.

Description

Technical Field

[0001] This application relates to the field of medical imaging, and more particularly to methods, apparatus, storage media, and electronic devices for blood flow laser speckle imaging. Background Technology

[0002] In the field of medical imaging, clearly depicting blood perfusion in human blood vessels is crucial for clinical diagnosis and disease assessment (such as identifying ischemic areas and necrotic tissue). Laser speckle imaging, as a hemodynamic imaging technique, offers advantages such as being non-contact, non-invasive, requiring no contrast agents, providing high spatiotemporal resolution, and featuring a simple instrument structure. It has been widely applied in basic research and clinical applications in ophthalmology, neuroscience, microcirculation, and intraoperative monitoring. However, due to the scattering characteristics of human tissue, noise often exists in the acquired speckle images during laser speckle imaging. This noise can interfere with the accurate assessment of blood perfusion, affecting image quality and the reliability of subsequent analysis.

[0003] In existing technologies, methods for removing speckle noise mostly rely on filtering algorithms or single-region noise suppression models. Filtering algorithms mainly smooth abrupt noise in the image by weighted averaging of the gray values ​​of adjacent pixels in the image, utilizing the correlation between pixels to reduce the interference of high-frequency noise. Single-region noise suppression models first analyze the noise characteristics of a specific region in the image, establish a noise distribution model for that region, and then suppress the noise in that region in a targeted manner based on the model.

[0004] However, existing technologies have significant limitations: the scattered laser light from blood flow propagates to areas near the blood flow region within the space corresponding to static tissue, interfering with the scattered laser light from the static tissue. This causes the area near the blood flow region in the static tissue to appear as a dynamic region, forming a "pseudo-dynamic region" within the actual static region. Because the true and pseudo-dynamic regions are spatially adjacent and intermingled, they cannot be effectively separated in the image. Therefore, the boundary of the dynamic region presented in the image is the boundary of the pseudo-dynamic region, located outside the actual blood flow boundary, and cannot reflect the actual blood flow situation. Existing technologies struggle to accurately distinguish the image signals formed by the true and pseudo-dynamic regions, making it impossible to specifically remove the speckle signal from the pseudo-dynamic region. This easily leads to incomplete noise reduction or the accidental deletion of valid blood flow signals, ultimately resulting in a significant reduction in the quality of blood speckle images.

[0005] Therefore, how to reduce the noise caused by blood flow interference with static tissues in current laser speckle imaging technology is an urgent technical problem to be solved. Summary of the Invention

[0006] This invention provides a method, apparatus, storage medium, and electronic device for blood flow laser speckle imaging. This method addresses the technical problem in the prior art of effectively reducing noise caused by blood flow interference with static tissues.

[0007] To achieve the above objectives, the first aspect of this application provides a blood flow laser speckle imaging method, comprising: S1: Control the laser to move from the outer edge of the initial dynamic region toward the initial dynamic region to form multiple corresponding laser speckle sub-images until the speckle fluctuation of the laser speckle sub-image changes abruptly. Define the laser speckle sub-image formed at the time of the change as image A, and define the laser speckle sub-image that is closest to image A in time sequence as image B. The irradiation area B corresponding to the front end of image B in the laser movement direction overlaps with the irradiation area A corresponding to the change area of ​​image A. S2: Analyze and compare image A and image B to determine the boundaries of blood flow; S3: Divide the dynamic region into a static region based on this boundary.

[0008] In the first possible implementation of the first aspect: S1 also includes: S11: Determine whether the area of ​​the mutation region in image A exceeds a preset area threshold; S12: If so, reduce the laser step distance and reacquire image A and image B.

[0009] In the second possible implementation of the first aspect: The boundary of the laser irradiation area on the front side of the laser movement direction is adapted to the boundary of the initial dynamic region on the side closer to the irradiation area B.

[0010] In the third possible implementation of the first aspect: S13: Acquire image C, the position corresponding to the front boundary of image C in the laser movement direction is located between the positions corresponding to the front boundaries of image A and image B in the laser movement direction; S14: Determine whether dynamic speckle exists in image C; S15: If it does not exist, reduce the laser step distance and reacquire image A and image B.

[0011] In the fourth possible implementation of the first aspect: The step distance of the laser decreases as the center distance decreases, which is the distance between the boundary of the laser's irradiation range on the front side of the laser's movement direction and the center of the blood flow.

[0012] In the fifth possible implementation of the first aspect: S21: Identify the abrupt change regions in image A; S22: Extract the image boundary of image B and the region corresponding to the mutation region as the boundary of blood flow.

[0013] Combining the first aspect, the first possibility of the first aspect, the second possibility of the first aspect, the third possibility of the first aspect, the fourth possibility of the first aspect, or the fifth possibility of the first aspect, in the sixth possible implementation method of the first aspect: S1 includes: S16: Control the laser A to move from the outer edge of the initial dynamic region toward the initial dynamic region to form multiple corresponding laser speckle sub-images until the speckle fluctuation of the laser speckle sub-image changes abruptly. Define the laser speckle sub-image formed at the time of the change as image A1. Define the laser speckle sub-image that is closest to image A1 in time sequence as image B1. The irradiation area B1 corresponding to the front end of image B1 in the laser movement direction overlaps with the irradiation area A1 corresponding to the change area of ​​image A1. S17: Control the laser B to move from the outer edge of the initial dynamic region toward the initial dynamic region to form multiple corresponding laser speckle sub-images until the speckle fluctuation of the laser speckle sub-image changes abruptly. Define the laser speckle sub-image formed at the time of the change as image A2, and define the laser speckle sub-image that is closest to image A2 in time sequence as image B2. The laser A and laser B move in opposite directions. The irradiation area B2 corresponding to the front end of image B2 in the laser moving direction overlaps with the irradiation area A2 corresponding to the change area of ​​image A2. S2 includes: analyzing and comparing image A1 with image B1 and analyzing and comparing image A2 with image B2 to determine the boundaries on both sides of the blood flow.

[0014] A second aspect of this application provides a blood flow laser speckle imaging device, comprising: Imaging is performed using the first aspect or any one of the possible blood flow laser speckle imaging methods described in the first aspect; Laser emitting assembly, used to control the laser to perform step irradiation; Image acquisition component, used to acquire images of the laser-irradiated area; Image analysis components are used to analyze and compare images to determine the boundaries of blood flow.

[0015] A third aspect of this application provides a storage medium, comprising: It stores a computer program that, when executed by a processor, implements the first aspect or any possible blood flow laser speckle imaging method of the first aspect.

[0016] A fourth aspect of this application provides an electronic device, comprising: Processor; and The memory stores executable code, which, when executed by the processor, causes the processor to execute the first aspect or any possible blood flow laser speckle imaging method of the first aspect.

[0017] The technical solution provided in this application has the following beneficial effects: By controlling the laser to move and irradiate from the outer edge of the initial dynamic region towards it, multiple laser speckle sub-images are formed until the speckle fluctuations abruptly change, thus determining images A and B. The irradiated area B corresponding to the leading edge of image B in the laser's movement direction overlaps with the irradiated area A corresponding to the abrupt change in image A. Image A represents the image information of the laser just as it moves from static tissue into the blood flow region, i.e., the image after the laser has just crossed the blood flow boundary. By controlling the laser's step distance sufficiently small, the leading edge of image B in the movement direction corresponds precisely to or very close to the blood flow boundary. Therefore, the position on image B corresponding to the leading edge in the movement direction is the blood flow boundary or infinitely close to it. In this way, the blood flow boundary can be determined by analyzing and comparing images A and B. Since the irradiated area B overlaps with the irradiated area A, the blood flow boundary determined by this method will be located within the false boundary determined by the false dynamic region, that is, closer to the real blood flow boundary than the false boundary. Therefore, by dividing the dynamic and static regions of the image with the boundary determined by this method, the false dynamic region in the image can be effectively reduced to achieve effective noise reduction, thereby improving the quality of the final blood speckle image.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0020] Figure 1 This is a schematic flowchart of the blood flow laser speckle imaging method shown in the embodiments of this application; Figure 2 This is another schematic flowchart of the blood flow laser speckle imaging method shown in the embodiments of this application; Figure 3 This is another schematic flowchart of the blood flow laser speckle imaging method shown in the embodiments of this application; Figure 4This is another schematic flowchart of the blood flow laser speckle imaging method shown in the embodiments of this application; Figure 5 This is another schematic flowchart of the blood flow laser speckle imaging method shown in the embodiments of this application; Figure 6 This is another schematic flowchart of the blood flow laser speckle imaging method shown in the embodiments of this application; Figure 7 This is another schematic flowchart of the blood flow laser speckle imaging method shown in the embodiments of this application; Figure 8 This is a schematic diagram of the structure of an electronic device shown in an embodiment of this application. Detailed Implementation

[0021] Preferred embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0022] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0024] In the description of this application, it should be understood that the terms "thickness", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Example

[0026] Existing technologies have significant limitations in processing speckle signals formed between blood and static tissue. The scattered laser light from blood flow propagates to areas near the blood flow region within the static tissue, interfering with the scattered laser light and causing these areas to appear as dynamic regions—essentially "pseudo-dynamic regions" within the actual static area. Because true and pseudo-dynamic regions are spatially adjacent and intermingled, they cannot be effectively separated in the image. Therefore, the boundaries of the dynamic regions appearing in the image are actually the boundaries of the pseudo-dynamic regions, located outside the true blood flow boundaries, and fail to reflect the actual blood flow situation. Existing technologies struggle to accurately distinguish between the image signals formed by true and pseudo-dynamic regions, making it impossible to specifically remove speckle signals from pseudo-dynamic regions. This leads to incomplete noise reduction or the accidental deletion of valid blood flow signals, ultimately resulting in a significant reduction in the quality of blood speckle images. Therefore, reducing the noise caused by blood flow interference with static tissue is a pressing technical problem that needs to be solved in current laser speckle imaging technology.

[0027] To solve the above technical problems, the following is combined with the appendix. Figure 1 Detailed description of the technical solutions of the embodiments of this application: S1: Control the laser to move from the outer edge of the initial dynamic region toward the initial dynamic region to form multiple corresponding laser speckle sub-images, until the speckle fluctuation of the laser speckle sub-image changes abruptly. Define the laser speckle sub-image formed at the time of the change as image A, and define the laser speckle image that is closest to image A in time sequence as image B. The irradiation area B corresponding to the front end of B in the laser movement direction overlaps with the irradiation area A corresponding to the change area of ​​image A. It should be noted that in laser speckle imaging, when a laser irradiates biological tissue, the tiny structures within the tissue scatter the light. The coherence of the laser causes this scattered light to interfere in space, forming an alternating bright and dark speckle pattern. This step controls the laser to move from outside the initial dynamic region along a direction close to the initial dynamic region. Each irradiation creates a laser speckle image corresponding to the irradiated area, thus obtaining multiple corresponding laser speckle sub-images. The laser movement is not unlimited; it stops when the speckle fluctuations in the laser speckle sub-images abruptly change. When the speckle pattern undergoes a sudden change, i.e., when the laser just crosses from static tissue into the blood flow region, the resulting laser speckle sub-image is defined as image A. Simultaneously, the laser speckle sub-image that is closest to image A in time sequence is defined as image B. This is because the irradiated area B corresponding to the leading edge of image B in the laser's movement direction overlaps with the irradiated area A corresponding to the abrupt change in image A. Therefore, by controlling the laser's step distance sufficiently, it can be ensured that the laser crosses into the blood flow region from or very close to the blood flow boundary. Thus, the position corresponding to the leading edge of image B in the laser's movement direction is the blood flow boundary or infinitely close to it. This process, by dynamically tracking the speckle changes formed by laser irradiation, provides direct image evidence for subsequently distinguishing between blood flow and static tissue regions.

[0028] It should be further explained that when the speckle fluctuation changes abruptly, in image A formed by laser irradiation, the abrupt change area corresponds to a portion of the blood flow area and the static tissue (the part covered by the pseudo-dynamic area) near this blood flow area, i.e., the irradiated area A. The blood flow boundary is also within the irradiated area A. According to the characteristics of laser speckle, the blood flow boundary is within the red dynamic area of ​​image A. Image B, as the laser speckle sub-image that is temporally closest to image A, represents the speckle image of the static tissue area closest to the blood flow area. The irradiated area B corresponding to the front end of image B in the laser movement direction overlaps with the irradiated area A corresponding to the abrupt change area of ​​image A. That is, irradiated area A and irradiated area B intersect, meaning that the rear end of irradiated area A and the front end of irradiated area B are the same area. Therefore, the position corresponding to the front boundary of image B in the movement direction is the blood flow boundary or very close to the blood flow boundary. Thus, the position corresponding to the front boundary of image B can be used as the blood flow boundary.

[0029] The initial dynamic region refers to the area of ​​blood flow activity determined by existing technology. It includes the actual blood flow area and the static tissue corresponding to the pseudo-dynamic region formed by interference from the blood flow area. It is the target approach area of ​​the laser moving irradiation and can be determined by overall imaging using existing imaging technology. Due to the blood flow in this area, the speckle image formed after laser irradiation will show low-contrast blue-red characteristics, which is significantly different from the high-contrast pure blue speckle in the static tissue area.

[0030] The initial dynamic region refers to the non-blood flow area determined by existing imaging techniques. It includes static tissue not covered by the false dynamic region, containing tissues without flowing blood such as skin, muscle, connective tissue, and bone, which are relatively stationary during imaging. When a laser irradiates this area, it scatters light with the microstructures of these tissues (such as cells and fibers), forming a high-contrast pure blue speckle image. The laser's movement from this region signifies that the initial irradiation position is in an environment without blood flow interference. The process of the laser moving towards the initial dynamic region is essentially a gradual advancement from a non-blood flow area towards a dynamic region with blood flow.

[0031] Laser speckle sub-images are local images formed when a laser irradiates a target area, due to scattering and interference between the laser and the microstructure of the tissue within the area (such as cells and fibers in static tissues, or blood components flowing in blood vessels). In this embodiment, the irradiated area is a rectangular block, which is gradually moved in a progressive manner, specifically at very small step intervals. After irradiating at each new location, a corresponding local image is generated; these local images are laser speckle sub-images. Different tissue characteristics in different areas will cause the speckle sub-images to exhibit different features: in static tissue areas without blood flow, the speckle sub-image appears as a high-contrast pure blue; while in vascular areas, the speckle is blurred due to blood flow, and the speckle sub-image appears as a low-contrast red. These sub-images record the speckle state at the corresponding irradiated location. It should be noted that the "very small intervals" are to ensure that the front boundary of the irradiated area corresponding to image B coincides with or infinitely approaches the real blood flow boundary from the outside. The exact size needs to be adjusted based on the required imaging precision—the higher the precision requirement, the smaller the interval, in order to ensure that abrupt changes in speckle fluctuations at the boundary can be accurately captured, providing a clear basis for subsequently accurately distinguishing the boundary between blood flow and static tissue.

[0032] Image A is a laser speckle sub-image formed when the speckle fluctuation of the laser speckle sub-image undergoes an abrupt change during the laser's movement from the outer edge of the initial dynamic region towards the region. This abrupt change is related to the presence of blood flow, and its speckle characteristics exhibit low contrast and a bluish-red hue, reflecting the emergence of a blood flow boundary. Image B is the laser speckle sub-image that is temporally closest to Image A, i.e., the adjacent image before the abrupt change in speckle fluctuation. Its speckle characteristics are characterized by high contrast and a pure blue hue, corresponding to the state of a static tissue area without blood flow. The difference in speckle characteristics between Images A and B provides direct image evidence for subsequent analysis and comparison to determine the blood flow boundary.

[0033] Specifically, laser movement is controlled by a precision electric translation stage through laser scanning and image analysis technology, while a high-speed camera simultaneously acquires speckle sub-images. Combined with digital image processing algorithms, abrupt changes in speckle fluctuations are identified, and images A and B are automatically labeled. Alternatively, laser movement and image acquisition can be accomplished using technologies such as galvanometer scanning and stepper motor drive.

[0034] Optionally, if the front boundary of the laser irradiation area does not match the boundary of the initial dynamic area near the irradiation area B, the irradiated area near the blood flow boundary will be partly blood flow and partly static tissue, thus failing to accurately capture the true blood flow boundary. To solve the above problem, in conjunction with the attached... Figure 3 By aligning the front boundary of the laser-irradiated area in the direction of movement with the boundary of the initial dynamic region near the irradiated area B, the front boundary of image B can coincide with the boundary of the initial dynamic region near the initial laser irradiation side. This alignment ensures that the front boundary of the laser-irradiated area B completely covers the actual blood flow boundary, preventing a situation where part of the front boundary of the irradiated area has crossed into the blood flow region while part remains within static tissue. Alternatively, the front boundary of the laser-irradiated area can be set as a sufficiently short straight line, since the blood flow boundary can be divided into multiple straight line segments if the segment size is small enough. Specifically, the laser distribution can be adjusted using spatial light modulation technology, and the same effect can be achieved by combining a galvanometer scanning system with path planning.

[0035] Preferably, when the laser moves and irradiates at a single interval, a large interval can increase the scanning speed, but near the edge of the blood vessel, the large step size can lead to inaccurate capture of abrupt changes in speckle fluctuations, resulting in missed boundary details; a small interval, while improving accuracy, increases the overall scanning time and reduces efficiency. To solve the above technical problems, combined with the attached... Figure 5This embodiment solves the aforementioned technical problem by reducing the laser's step distance as the center distance decreases. In this embodiment, the center distance refers to the distance between the leading boundary of the irradiated area and the blood flow center when the laser irradiates the target area. When the center distance is large, a larger step distance is used to allow the laser to move quickly, improving overall efficiency; conversely, as the center distance decreases, a smaller step distance is used, which more accurately captures abrupt changes in speckle fluctuations, thus balancing efficiency and accuracy in boundary determination. To determine the blood flow center, the initial dynamic area is first irradiated with a single laser to obtain a laser speckle image. Then, the blood flow region is determined on the speckle image, and the center of the blood flow region in its extension direction is taken as the blood flow center. In addition, the following approach can be adopted: A larger interval d1 is used during the initial laser movement to quickly cover areas far from blood vessels, improving overall scanning efficiency. When the distance between the center of the laser irradiation area and the center of the blood vessel is less than a preset distance D (i.e., close to the blood flow edge), the interval is switched to a smaller interval d2. At this point, the small step size movement can more delicately capture subtle changes in speckle fluctuations, ensuring accurate identification of abrupt changes and precise positioning of blood flow boundaries. Specifically, this process can be achieved using precision motion control and image analysis linkage technology, driving the laser to move at intervals d1, and combining image recognition to calculate the distance between the laser and the center of the blood vessel in real time. When the distance is less than the preset distance D, the interval is switched to a smaller interval d2 until a sudden change in speckle fluctuations is detected. A similar operation can also be accomplished using a servo control system combined with machine vision technology.

[0036] Preferably, during laser irradiation, the range of speckle fluctuations may become too large due to the laser traversing too much of the blood flow boundary. This results in image A containing numerous speckle features simultaneously, making it impossible to clearly distinguish the specific location of the boundary, thus causing the technical problem of blurred boundary localization and difficulty in precise determination. In this case, the excessively large range of fluctuations means that the previous movement step length has not been sufficient to capture the boundary details, failing to meet the requirements for locating the vascular boundary. To solve the above technical problem, combined with the attached... Figure 2 When the range of abrupt changes on image A exceeds the threshold, the laser is controlled to return to the position corresponding to image B, and then moves back to the initial dynamic area for irradiation with a smaller step distance. The smaller step length can collect speckle information more densely and capture the gradual process of speckle fluctuations from static to dynamic more delicately, so that the front boundary of the irradiated area corresponding to image B falls on or is closer to the blood flow boundary.

[0037] S2: Analyze and compare image A and image B to determine the boundaries of blood flow; It should be noted that: Image A is the image formed when the speckle fluctuation of the laser speckle sub-image undergoes a sudden change. At this point, the laser has irradiated the blood flow area, and the speckle exhibits low-contrast, blurred red-blue spot characteristics. Image B is the laser speckle sub-image that is temporally closest to Image A, representing the static tissue area at the edge of the blood flow region, where the speckle exhibits high-contrast, clear blue spot characteristics. By combining Image A with Image B and determining the position of the boundary of Image B in the forward direction of movement, the blood flow boundary can be determined.

[0038] Preferred, combined with appendix Figure 6 In determining the blood flow boundary by comparing images A and B, the following method can be used: First, determine the irradiated region A corresponding to the range of abrupt changes in speckle fluctuations in image A. Irradiated region A reflects the speckle characteristics near the blood flow boundary. Extract the irradiated region B corresponding to the front end of image B. Finally, take the front boundary of irradiated region B within irradiated region A as the blood flow boundary. It is important to note that if irradiated region B is within irradiated region A, then its front boundary can be considered the blood flow boundary; conversely, if irradiated region B is not within irradiated region A, its front boundary cannot be determined as the blood flow boundary. This is because the blood flow boundary must be contained within the irradiated region A corresponding to image A, and irradiated region B outside this range is clearly irrelevant to the true boundary. It should be noted that while determining the position corresponding to the front boundary of image B as the blood flow boundary cannot guarantee absolute accuracy, it effectively eliminates most of the interference from noise speckle. This is because image B reflects the speckle characteristics of static tissue, and the position corresponding to its anterior boundary is within the irradiated area A, meaning the anterior boundary falls within the "pseudo-dynamic region." Therefore, the blood flow boundary determined by this anterior boundary is closer to the real blood boundary than the "pseudo boundary." Thus, using this method to define the blood flow boundary to separate the blood flow region from the static tissue can effectively reduce noise caused by the blood flow region interfering with the static tissue. Furthermore, when the laser's step distance is sufficiently small, image A can more accurately capture the speckle abrupt changes at the boundary, and the position corresponding to the anterior edge of image B can fall on or be very close to the real blood flow boundary, improving the positioning accuracy of the blood flow boundary.

[0039] Preferably, combining the foregoing content and appendix Figure 4Further verification can be used to determine whether the position corresponding to the front boundary of image B is close enough to the actual blood flow boundary: at the imaging position of image B, the laser is controlled to move with a step distance smaller than that used when image A was formed, and image C is formed. That is, the front boundary of the irradiated area C corresponding to image C is located between the front boundary of irradiated area A and the front boundary of irradiated area B. If speckle features (i.e., speckle features reflecting the presence of blood flow) appear in image C, it indicates that the edge of image B is reliable as a blood vessel boundary; if no speckle features appear in image C, it indicates that the position corresponding to the front boundary of image B is still far from the actual blood flow boundary. In this case, the laser can be moved with a smaller step distance based on image C, and images A and B can be re-acquired to determine a more accurate blood flow boundary. This process further reduces the risk of misjudgment and ensures the accuracy of boundary positioning through verification and supplementary imaging with smaller step distances.

[0040] S3: Divide the dynamic region into a static region based on the boundary.

[0041] It should be noted that during imaging, speckle signals from blood flow and static tissues are often mixed together, while a defined boundary provides a spatial distinction. Using this boundary as a reference, speckle signals from the blood flow region within the boundary are extracted, while interference from speckle signals from static tissues outside the boundary is eliminated, ultimately yielding a laser speckle image that reflects only the blood flow within the vessel. This process effectively removes irrelevant static tissue information, providing clear and targeted image data for subsequent analysis of blood perfusion, ensuring that the evaluation focuses on blood flow-related features.

[0042] Preferably, blood vessels, as tubular structures, have two opposing boundaries. If only one boundary is determined through unidirectional scanning, the other boundary, if uncertain, will still result in a large amount of noise and speckle mixing into the blood flow image, affecting the accuracy of subsequent analysis. (See attached...) Figure 7 To address the aforementioned technical challenges, lasers A and B are moved in opposite directions to capture abrupt changes in speckle ripple patterns along the edges of the blood vessel. Images A1 and B1 define one boundary, while images A2 and B2 define the other. These two boundaries together constitute the complete spatial extent of blood flow. When dividing dynamic and static regions using these boundaries, all static tissue signals outside the boundaries can be excluded, avoiding interference from static tissue noise on the other side during unilateral boundary division. Furthermore, the coordinated localization of the two boundaries allows for more precise framing of the blood flow region, ensuring that the extracted speckle images contain only blood flow information within the vessel. This provides noise-free, clearly defined image data for clinical assessment, significantly improving detection accuracy.

[0043] Beneficial effects: By controlling the laser to move and irradiate from the outer edge of the initial dynamic region towards the initial dynamic region, multiple laser speckle sub-images are formed until the speckle fluctuations undergo a sudden change, thereby determining image A and image B. The irradiated area B corresponding to the leading edge of image B in the laser movement direction overlaps with the irradiated area A corresponding to the abrupt change region in image A. Image A represents the image information of the laser just as it moves from static tissue into the blood flow region, i.e., the image after the laser has just crossed the blood flow boundary. By controlling the laser step distance sufficiently small, the leading edge of image B in the movement direction corresponds exactly to or very close to the blood flow boundary. Therefore, the position corresponding to the leading edge of image B in the movement direction is the blood flow boundary or infinitely close to it. In this way, the blood flow boundary can be determined by analyzing and comparing images A and B. Since the irradiated area B overlaps with the irradiated area A, the blood flow boundary determined by this method will be located within the false boundary determined by the false dynamic region, that is, closer to the real blood flow boundary than the false boundary. Therefore, by dividing the dynamic and static regions of the image with the boundary determined by this method, the false dynamic region in the image can be effectively reduced to achieve effective noise reduction, thereby improving the quality of the final blood speckle image. Example

[0044] This embodiment provides a blood flow laser speckle imaging device for implementing the blood flow laser speckle imaging method provided in the foregoing embodiments, comprising: A laser emitting component is used to control the laser to perform step irradiation. It typically includes a semiconductor laser and a driving circuit. It can be paired with scanning modules such as MEMS micro-mirrors to achieve precise moving irradiation. The step distance is controlled by adjusting the driving parameters.

[0045] The image acquisition component is used to acquire images of the area irradiated by the laser. It is generally composed of a CCD or CMOS image sensor and an image acquisition circuit. It can convert optical signals into digital image data and is triggered synchronously with the laser emission component to ensure image accuracy.

[0046] The image analysis component is used to analyze and compare images to determine blood flow boundaries. It relies on algorithms such as Canny edge detection and image processing technology to compare the abrupt changes in speckle fluctuations in the image and combine information such as grayscale and texture to identify blood flow boundaries. Example

[0047] An electronic device according to this embodiment includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus. The following is in conjunction with the appendix Figure 8 The technical solutions of the embodiments of this application are described in detail.

[0048] Memory, used to store computer programs; When a processor executes a program stored in memory, it implements the method steps of the above-described embodiments.

[0049] This embodiment provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method steps of the above embodiment.

[0050] The memory in this application embodiment can be volatile memory or non-volatile memory, or it can include both volatile and non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), which is used as an external cache.

[0051] By way of example, but not limitation, many forms of RAM are available, such as static RAM, SRAM, dynamic RAM, DRAM, synchronous DRAM, SDRAM, double data rate SDRAM, DDR SDRAM, enhanced synchronous DRAM, ESDRAM, synchronous link DRAM, SLDRAM, and direct memory bus RAM, DRRAM.

[0052] It should be noted that the memory of the methods described in this invention is intended to include, but is not limited to, these and any other suitable types of memory. In the above embodiments, it can be implemented wholly or partially by software, hardware, firmware, or any combination thereof.

[0053] When implemented using software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When these computer instructions are loaded and executed on a computer, they, in whole or in part, produce the processes or functions according to the embodiments of this application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired means such as coaxial cable, fiber optic cable, digital subscriber line (DSL), or wireless means such as infrared, wireless, microwave, etc.

[0054] Computer-readable storage media can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media. Available media can be magnetic media such as floppy disks, hard disks, and magnetic tapes; optical media such as high-density digital video discs (Digital Video Discs) and DVDs; or semiconductor media such as solid-state drives (SSDs).

[0055] In implementation, each step of the above method can be completed by integrated logic circuits in the processor hardware or by instructions in software. The steps of the method disclosed in the embodiments of this application can be directly embodied in the execution of hardware processor, or by a combination of hardware and software modules in the processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art.

[0056] The storage medium is located in the memory. The processor reads the information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, these will not be described in detail here.

[0057] It should be noted that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above methods.

[0058] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated further here.

[0059] The solution of this application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of each embodiment have different emphases; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. Those skilled in the art should also understand that the actions and modules involved in the specification are not necessarily essential to this application. Furthermore, it is understood that the steps in the method of this application embodiment can be adjusted, combined, and deleted according to actual needs, and the modules in the device of this application embodiment can be combined, divided, and deleted according to actual needs.

[0060] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A blood flow laser speckle imaging method, characterized in that, include: S1: Control the laser to move from the outer edge of the initial dynamic region toward the initial dynamic region to form multiple corresponding laser speckle sub-images, until the speckle fluctuation of the laser speckle sub-image changes abruptly. Define the laser speckle sub-image formed at the time of the change as image A, and define the laser speckle sub-image that is closest to image A in time sequence as image B. The irradiation area B corresponding to the front end of image B in the laser movement direction overlaps with the irradiation area A corresponding to the change area of ​​image A. S2: Analyze and compare image A and image B to determine the boundaries of blood flow; S3: Divide the dynamic region into a static region based on the boundary.

2. The blood flow laser speckle imaging method according to claim 1, characterized in that: S1 also includes: S11: Determine whether the area of ​​the abrupt change region in image A exceeds a preset area threshold; S12: If so, reduce the laser step distance and reacquire the image A and the image B.

3. The blood flow laser speckle imaging method according to claim 1, characterized in that: The boundary of the laser irradiation area on the front side of the laser movement direction is adapted to the boundary of the initial dynamic region on the side closer to the irradiation area B.

4. The blood flow laser speckle imaging method according to claim 1, characterized in that, The period between S1 and S2 also includes: S13: Acquire image C, wherein the position corresponding to the front boundary of image C in the laser movement direction is located between the positions corresponding to the front boundaries of image A and image B in the laser movement direction; S14: Determine whether dynamic speckle exists in the image C; S15: If not, reduce the laser step distance and reacquire the image A and the image B.

5. The blood flow laser speckle imaging method according to claim 1, characterized in that: The stepping distance of the laser decreases as the center distance decreases, where the center distance is the distance between the boundary of the laser's irradiation range on the front side of the laser's movement direction and the center of the blood flow.

6. The blood flow laser speckle imaging method according to claim 1, characterized in that, S2 include: S21: Identify the abrupt change regions in image A; S22: Extract the image boundary of the region corresponding to the mutation region in image B as the boundary of the blood flow.

7. A blood flow laser speckle imaging method according to any one of claims 1 to 6, characterized in that: S1 includes: S16: Control the laser A to move from the outer edge of the initial dynamic region toward the initial dynamic region to form multiple corresponding laser speckle sub-images, until the speckle fluctuation of the laser speckle sub-image changes abruptly. Define the laser speckle sub-image formed at the time of the change as image A1, and define the laser speckle sub-image that is closest to image A1 in time sequence as image B1. The irradiation area B1 corresponding to the front end of image B1 in the laser movement direction overlaps with the irradiation area A1 corresponding to the change area of ​​image A1. S17: Control the laser B to move from the outer edge of the initial dynamic region toward the initial dynamic region to form multiple corresponding laser speckle sub-images until the speckle fluctuation of the laser speckle sub-image changes abruptly. Define the laser speckle sub-image formed at the time of the change as image A2, and define the laser speckle sub-image that is closest to image A2 in time sequence as image B2. The laser A and laser B move in opposite directions. The irradiation area B2 corresponding to the front end of image B2 in the laser moving direction overlaps with the irradiation area A2 corresponding to the change area of ​​image A2. S2 includes: analyzing and comparing image A1 with image B1 and analyzing and comparing image A2 with image B2 to determine the boundaries on both sides of the blood flow.

8. A blood flow laser speckle imaging device, characterized in that, Imaging using the blood flow laser speckle imaging method as described in any one of claims 1 to 7, comprising: Laser emitting assembly, used to control the laser to perform step irradiation; Image acquisition component, used to acquire images of the laser-irradiated area; Image analysis components are used to analyze and compare images to determine the boundaries of blood flow.

9. A storage medium, characterized in that... It stores a computer program that, when executed by a processor, implements the blood flow laser speckle imaging method as described in any one of claims 1 to 7.

10. An electronic device, characterized in that, include: processor; as well as A memory having executable code stored thereon, which, when executed by the processor, causes the processor to perform the blood flow laser speckle imaging method as described in any one of claims 1 to 7.

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