Method and apparatus for observing myocardial perfusion patterns

Abstract

The application provides a method and device for observing myocardial blood perfusion rules, wherein the method for observing myocardial blood perfusion rules comprises the following steps: acquiring a plurality of high signal-to-noise ratio dynamic speckle images of a pretreatment area on myocardium; acquiring three-dimensional position information of the pretreatment area; acquiring a blood perfusion amount space-time distribution map of the pretreatment area according to the high signal-to-noise ratio dynamic speckle images and the three-dimensional position information; and determining a to-be-treated area in the pretreatment area according to the blood perfusion amount space-time distribution map and a blood perfusion amount threshold value. The method and device for observing myocardial blood perfusion rules provided by the application are aimed at solving the problems of traditional technology that myocardial blood perfusion rules are not easy to observe and myocardial lesion areas are difficult to locate.

Description

Technical Field

[0001] This invention relates to the field of biomedical imaging technology, and in particular to a method and apparatus for observing the pattern of myocardial blood flow perfusion. Background Technology

[0002] Methods for imaging or measuring myocardial blood flow perfusion mainly include PET-CT myocardial blood flow perfusion measurement and real-time blood flow measurement technology. However, both have shortcomings such as insufficient spatiotemporal resolution and poor dynamic real-time imaging capabilities, failing to meet practical needs. Laser speckle blood flow imaging technology constructs the blood flow velocity distribution by analyzing the dynamic / static characteristic distribution of the coherent light field. In recent years, domestic and foreign scholars have conducted a series of studies on laser speckle blood flow imaging technology, achieving speckle imaging of blood flow in the retina, skin, and cerebral cortex, and continuously optimizing the software / hardware system parameters, effectively improving the sensitivity of laser speckle blood flow measurement and the resolution of blood flow imaging.

[0003] Unlike organs such as the retina and brain, the heart undergoes rapid deformation and has a high flow velocity (150 mm / s-600 mm / s). High-resolution, real-time, and accurate imaging of myocardial blood perfusion is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This invention provides a method and apparatus for observing myocardial blood flow perfusion patterns, aiming to solve the problems of difficulty in observing myocardial blood flow perfusion patterns and locating myocardial lesion areas in traditional techniques.

[0005] To address the above problems, this invention provides a method for observing myocardial blood flow perfusion patterns, characterized by comprising:

[0006] Acquire high signal-to-noise ratio dynamic speckle images of preprocessed regions on the myocardium in multiple frames;

[0007] Obtain the three-dimensional position information of the preprocessed area;

[0008] Based on the high signal-to-noise ratio dynamic speckle image and the three-dimensional position information, a spatiotemporal distribution map of blood perfusion in the preprocessed region is obtained;

[0009] Based on the spatiotemporal distribution map of blood perfusion and the blood perfusion threshold, the area to be processed in the preprocessing region is determined.

[0010] According to the present invention, a method for observing myocardial blood flow perfusion patterns, comprising obtaining a spatiotemporal distribution map of blood flow perfusion in the preprocessed region based on the high signal-to-noise ratio dynamic speckle image and the three-dimensional location information, including:

[0011] Based on the high signal-to-noise ratio dynamic speckle image, obtain the spatiotemporal distribution map of blood perfusion in the preprocessed region;

[0012] Based on the spatiotemporal distribution map of blood perfusion and the three-dimensional location information, a spatiotemporal distribution map of blood perfusion with three-dimensional location information is obtained for the preprocessed area.

[0013] According to the present invention, a method for observing myocardial blood flow perfusion patterns, comprising obtaining a spatiotemporal distribution map of blood flow perfusion in the preprocessed region based on the high signal-to-noise ratio dynamic speckle image, including:

[0014] Set the exposure time, with a range of 20μs-50μs, to acquire multiple frames of high signal-to-noise ratio dynamic speckle images;

[0015] Based on the following functions and a parameter fitting algorithm, the system coherence parameters, red blood cell scattering type, proportion of dynamic scattered light in total scattered light, detector noise, time delay of a certain image relative to time 0, and autocorrelation time of light intensity fluctuations are determined:

[0016]

[0017] Set the exposure time and acquire multiple frames of high signal-to-noise ratio dynamic speckle images again;

[0018] Based on the following functions, the speckle blood flow velocity index is determined and the speckle blood flow velocity index distribution matrix is ​​obtained according to the system coherence parameters, red blood cell scattering type, and camera exposure time (integration time):

[0019]

[0020] Based on the speckle blood flow velocity index distribution matrix and the vessel inner diameter area, the spatiotemporal distribution map of blood perfusion in the pre-processed area is obtained;

[0021] Where β is the system coherence parameter, n is the red blood cell scattering type, K is the speckle image contrast, ρ is the proportion of dynamic scattered light in the total scattered light, C is the detector noise, and τ c The autocorrelation time of light intensity fluctuations is given by τ, the time delay of an image relative to τ = 0 is given by X, the numerical value corresponding to the scattering type is given by d, the proportion of a certain scattering type in multiple scattering is given by T, and the camera exposure time (integration time) is given by T / τ. c t represents the speckle blood flow velocity index, and t represents the measurement time of the dynamic speckle image.

[0022] According to the present invention, a method for observing myocardial blood flow perfusion patterns, comprising obtaining a spatiotemporal distribution map of blood flow perfusion in the preprocessed region based on the high signal-to-noise ratio dynamic speckle image, including:

[0023] With appropriate gradient changes, set 6-20 different exposure times, with each exposure time ranging from 20μs to 100000μs. Obtain 6-20 sets of dynamic speckle images corresponding to different exposure times. Each set of dynamic speckle images includes multiple frames of dynamic speckle images.

[0024] Based on the parameter fitting algorithm, the speckle blood flow velocity index is determined and the speckle blood flow velocity index distribution matrix is ​​obtained according to the following formula:

[0025]

[0026] Based on the speckle blood flow velocity index distribution matrix and the vessel inner diameter area, the spatiotemporal distribution map of blood perfusion in the pre-processed area is obtained;

[0027] Among them, v ne The variance introduced by static scattered light, v noise ρ is the variance caused by experimental noise, β is the system coherence parameter, ρ is the proportion of dynamic scattered light in the total scattered light, and T / τ is the system coherence parameter. c The blood flow velocity index is for speckled patterns.

[0028] According to the present invention, a method for observing myocardial blood flow perfusion patterns, comprising obtaining a spatiotemporal distribution map of blood flow perfusion in the preprocessed region based on the high signal-to-noise ratio dynamic speckle image, including:

[0029] Obtain the speckle contrast of a static speckle image to determine the system coherence parameters;

[0030] Acquire multi-frame dynamic speckle images and determine the spatiotemporal speckle contrast;

[0031] Based on the spatiotemporal speckle contrast and system coherence parameters, the speckle blood flow velocity index is determined and the speckle blood flow velocity index distribution matrix is ​​obtained using the following functions:

[0032]

[0033] Based on the speckle blood flow velocity index distribution matrix and the vessel inner diameter area, the spatiotemporal distribution map of blood perfusion in the pre-processed area is obtained;

[0034] Where β is the system coherence parameter, K is the spatiotemporal speckle contrast, and T / τ c The blood flow velocity index is for speckled patterns.

[0035] According to a method for observing myocardial blood perfusion patterns provided by the present invention, obtaining a spatiotemporal distribution map of blood perfusion in a preprocessed region based on the spatiotemporal distribution map of blood perfusion and the three-dimensional location information includes:

[0036] The three-dimensional location information is then appended to each pixel of the spatiotemporal distribution map of blood perfusion to obtain a spatiotemporal distribution map of blood perfusion with three-dimensional location information.

[0037] The present invention also provides a device for observing the pattern of myocardial blood flow perfusion, comprising:

[0038] Electrocardiogram (ECG) monitoring equipment is used to collect ECG signals, specifically the R wave.

[0039] The laser speckle blood flow imaging module is used to acquire dynamic speckle images of a pre-processed area on the myocardium under the triggering of the R wave acquired by the electrocardiogram monitoring device.

[0040] A lidar three-dimensional imaging module is used to acquire three-dimensional position information of the preprocessed area under the triggering of the R wave acquired by the electrocardiogram monitoring device;

[0041] A laser projection navigation module is used to project the area to be treated on the myocardium; and,

[0042] The control system includes an image fusion module and a region-to-be-processed determination module. The image fusion module is used to obtain a spatiotemporal distribution map of blood perfusion in the preprocessed region based on the dynamic speckle image and three-dimensional position information of the preprocessed region. The region-to-be-processed determination module is used to determine the region-to-be-processed based on the spatiotemporal distribution map of blood perfusion and a preset blood perfusion threshold.

[0043] According to the present invention, a device for observing myocardial blood flow perfusion patterns is provided, wherein the laser speckle blood flow imaging module includes a near-infrared laser, a filtering and beam expanding section, a dichroic mirror, a first beam splitter, and an imaging section. The laser wavelength of the near-infrared laser is 630-900nm, and the light intensity of the near-infrared laser satisfies the linear range of the photoelectric conversion efficiency of the imaging section.

[0044] According to the present invention, an apparatus for observing myocardial blood flow perfusion patterns is provided, wherein the imaging unit includes a combination lens, a narrow-band filter, a polarizer, and a high-speed charge coupler.

[0045] According to the present invention, an apparatus for observing myocardial blood flow perfusion patterns is provided, wherein the image acquisition frame rate of the laser speckle blood flow imaging module is greater than the reciprocal of the myocardial blood flow decorrelation time, the operating speed of the laser speckle blood flow imaging module is higher than the rate of external vibration noise, and the image bit depth of the laser speckle blood flow imaging module includes 8-bit, 10-bit, 12-bit, or 16-bit.

[0046] According to the present invention, a device for observing myocardial blood flow perfusion patterns is provided, wherein the lidar three-dimensional imaging module includes a near-infrared laser, a collimator homogenizer, a second beam splitter, a dichroic mirror, and a photoelectric receiver, wherein the laser wavelength of the near-infrared laser is 808-940nm.

[0047] According to the present invention, a device for observing myocardial blood flow perfusion patterns is provided, wherein the laser projection navigation module includes a visible light laser, two filtering beam expanders, a spatial light modulator, a first reflector, and a second reflector, wherein the laser wavelength of the visible light laser is 400-700nm.

[0048] According to the present invention, a device for observing myocardial blood flow perfusion patterns is provided, wherein the spatial light modulator includes a digital micro-mirror or a liquid crystal spatial light modulator.

[0049] According to the present invention, an apparatus for observing myocardial blood flow perfusion patterns is provided, wherein the filtering and expanding section includes a free space filtering and expanding section or an optical fiber filtering and expanding section.

[0050] According to the present invention, a device for observing myocardial blood flow perfusion patterns is provided, wherein the filtering and beam expanding section includes a first lens, a pinhole, and a second lens.

[0051] This invention provides a method for observing myocardial blood flow perfusion patterns, combining three technologies: dynamic scattered light-laser speckle contrast imaging, lidar three-dimensional imaging, and laser projection display. These three optical technologies offer advantages such as no ionizing radiation, non-invasive measurement, and no need for contrast agent injection, achieving sub-micron spatial resolution and millimeter-level penetration depth into biological tissues. The method provided by this invention can display the spatiotemporal evolution of myocardial blood flow perfusion in real time, and can be used to monitor and compare changes in myocardial blood flow perfusion before and after coronary artery bypass grafting (CABG), which is of great significance for the effective implementation of CABG procedures and the quantitative evaluation of postoperative outcomes. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0053] Figure 1 This is a flowchart illustrating the method for observing myocardial blood flow perfusion patterns provided by the present invention.

[0054] Figure 2 This is a schematic diagram of the device provided by the present invention for observing the pattern of myocardial blood flow perfusion;

[0055] Figure 3 yes Figure 2 Schematic diagram of the structure of the laser speckle blood flow imaging module;

[0056] Figure 4 yes Figure 2 A schematic diagram of the structure of the three-dimensional imaging module of the lidar;

[0057] Figure 5 yes Figure 2 A schematic diagram of the structure of the laser projection navigation module;

[0058] Reference numerals: 1: Laser speckle blood flow imaging module; 2: LiDAR 3D imaging module; 3: Laser projection navigation module; 4: Visible light laser; 5: Filtering and beam expanding section; 6: First lens; 7: Pinhole; 8: Second lens; 9: Dichroic mirror; 10: First beam splitter; 11: Imaging section; 12: Collimator and homogenizer; 13: Second beam splitter; 14: Photodetector; 15: Spatial light modulator; 16: First reflector; 17: Second reflector. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0060] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "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 the embodiments of the present invention 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 the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0062] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0063] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0064] The following is combined Figures 1-5 The present invention describes a method and apparatus for observing myocardial blood flow perfusion patterns.

[0065] Please see Figure 1 This invention provides a method for observing myocardial blood flow perfusion patterns, comprising:

[0066] S100: Acquire high signal-to-noise ratio dynamic speckle images of preprocessed regions on the myocardium in multiple frames;

[0067] S200: Obtain the three-dimensional position information of the preprocessed area;

[0068] S300. Based on the high signal-to-noise ratio dynamic speckle image and the three-dimensional position information, obtain the spatiotemporal distribution map of blood perfusion in the preprocessed area;

[0069] S400. Based on the spatiotemporal distribution map of blood perfusion and the blood perfusion threshold, determine the region to be processed in the preprocessing region.

[0070] The heart is in a state of rapid deformation and high flow velocity. High-resolution, real-time, and accurate imaging of myocardial blood perfusion is a technical problem urgently needing to be solved by those skilled in the art. The method for observing myocardial blood perfusion patterns provided by this invention first acquires a dynamic speckle image of a pre-processed area on the myocardium using laser speckle technology. Based on this dynamic speckle image, a spatiotemporal distribution map of blood perfusion in the pre-processed area can be obtained. Second, three-dimensional location information of the pre-processed area can be acquired using laser technology. By comprehensively processing the spatiotemporal distribution map and the three-dimensional location information, the blood perfusion volume at each location within the pre-processed area can be intuitively obtained. Comparing the blood perfusion volume threshold with the actual blood perfusion volume identifies abnormal points, forming areas to be processed. The method for observing myocardial blood perfusion patterns provided by this invention can display the spatiotemporal evolution of myocardial blood perfusion in real time. It can be used to monitor changes in myocardial blood perfusion volume before and after coronary artery bypass grafting (CABG), which is of great significance for the effective implementation of CABG surgery and the quantitative evaluation of postoperative outcomes.

[0071] Specifically, S300, obtaining the spatiotemporal distribution map of blood perfusion in the preprocessed region based on the high signal-to-noise ratio dynamic speckle image and the three-dimensional position information includes:

[0072] S310. Based on the high signal-to-noise ratio dynamic speckle image, obtain the spatiotemporal distribution map of blood perfusion in the preprocessed region;

[0073] S320. Based on the spatiotemporal distribution map of blood perfusion and the three-dimensional location information, obtain the spatiotemporal distribution map of blood perfusion with three-dimensional location information in the preprocessed area.

[0074] As mentioned above, in the technical solution provided by the present invention, the acquisition of data includes two steps: first, acquiring a dynamic speckle image of the preprocessed area; and second, acquiring the three-dimensional position information of the preprocessed area. The processing of data also includes two steps: first, processing the dynamic speckle image to obtain a spatiotemporal distribution map of blood perfusion in the preprocessed area; and second, integrating the three-dimensional position information with the spatiotemporal distribution map to obtain a spatiotemporal distribution map of blood perfusion with three-dimensional position information.

[0075] Furthermore, regarding how to obtain the spatiotemporal distribution map of blood perfusion volume from dynamic speckle images, this invention provides three implementation methods. In the first implementation method, S310, obtaining the spatiotemporal distribution map of blood perfusion volume in the preprocessed region based on the high signal-to-noise ratio dynamic speckle image includes:

[0076] S311. Set the exposure time, with a range of 20μs-50μs, to acquire multiple frames of high signal-to-noise ratio dynamic speckle images;

[0077] S312. Based on the following functions and according to the parameter fitting algorithm, determine the system coherence parameters, red blood cell scattering type, proportion of dynamic scattered light in the total scattered light, detector noise, time delay of a certain image relative to time 0, and autocorrelation time of light intensity fluctuations:

[0078]

[0079] S313. Set the exposure time and acquire multiple frames of high signal-to-noise ratio dynamic speckle images again;

[0080] S314. Based on the following functions, determine the speckle blood flow velocity index and obtain the speckle blood flow velocity index distribution matrix according to the system coherence parameters, red blood cell scattering type, and camera exposure time (integration time):

[0081]

[0082] S315. Based on the speckle blood flow velocity index distribution matrix and the vessel inner diameter area, obtain the spatiotemporal distribution map of blood perfusion in the pre-processed area;

[0083] Where β is the system coherence parameter, n is the red blood cell scattering type, K is the speckle image contrast, ρ is the proportion of dynamic scattered light in the total scattered light, C is the detector noise, and τ c The autocorrelation time of light intensity fluctuations is given by τ, the time delay of an image relative to τ = 0 is given by X, the numerical value corresponding to the scattering type is given by d, the proportion of a certain scattering type in multiple scattering is given by T, and the camera exposure time (integration time) is given by T / τ. c t represents the speckle blood flow velocity index, and t represents the measurement time of the dynamic speckle image.

[0084] The first implementation involves two acquisitions of dynamic speckle images. The first acquisition requires a short exposure time, ranging from 20μs to 50μs. Within this exposure time, multiple frames of dynamic speckle images are acquired. Based on a parameter fitting algorithm, the system coherence parameter β, the red blood cell scattering type n, the proportion of dynamic scattered light in the total scattered light d, the detector noise C, the time delay of a certain image relative to time 0, and the autocorrelation time τ of light intensity fluctuations are determined.

[0085] After determining the relevant parameters, a second dynamic speckle image needs to be acquired. The exposure time for this second acquisition can be set based on the experience of those skilled in the art and has no special requirements. After acquiring multiple frames of dynamic speckle images again, the system parameters obtained in the above steps are substituted into the formula, and the speckle blood flow velocity exponential distribution matrix can be obtained, and then the spatiotemporal distribution map of blood perfusion can be obtained.

[0086] Specifically, in the second embodiment, S310, obtaining the spatiotemporal distribution map of blood perfusion in the preprocessed region based on the high signal-to-noise ratio dynamic speckle image includes:

[0087] S311'. According to a suitable gradient change, set 6-20 different exposure times, with each exposure time ranging from 20μs to 100000μs. Obtain 6-20 sets of dynamic speckle images corresponding to different exposure times. Each set of dynamic speckle images includes multiple frames of dynamic speckle images.

[0088] S312'. Based on the parameter fitting algorithm, determine the speckle blood flow velocity index and obtain the speckle blood flow velocity index distribution matrix according to the following formula:

[0089]

[0090] S313'. Based on the speckle blood flow velocity index distribution matrix and the vessel inner diameter area, obtain the spatiotemporal distribution map of blood perfusion in the pre-processed area;

[0091] Among them, v ne The variance introduced by static scattered light, v noise ρ is the variance caused by experimental noise, β is the system coherence parameter, ρ is the proportion of dynamic scattered light in the total scattered light, and T / τ is the system coherence parameter. c The blood flow velocity index is for speckled patterns.

[0092] It should be noted that in the second embodiment, 6-20 sets of dynamic speckle images need to be acquired, with 15 sets being the optimal value. Each set of dynamic speckle images includes multiple frames of dynamic speckle images. Then, based on the parameter fitting algorithm and the formula, the spatiotemporal distribution map of blood perfusion can be obtained.

[0093] Further, S310, obtaining the spatiotemporal distribution map of blood perfusion in the preprocessed region based on the high signal-to-noise ratio dynamic speckle image includes:

[0094] S311”: Obtain the speckle contrast of a static speckle image and determine the system coherence parameters;

[0095] S312”: Acquire multi-frame dynamic speckle images and determine spatiotemporal speckle contrast;

[0096] S313' Based on the spatiotemporal speckle contrast and system coherence parameters, the speckle blood flow velocity index is determined and the speckle blood flow velocity index distribution matrix is ​​obtained using the following functions:

[0097]

[0098] S314”: Based on the speckle blood flow velocity index distribution matrix and the inner diameter area of ​​the blood vessel, obtain the spatiotemporal distribution map of blood perfusion in the pre-processed area;

[0099] Where β is the system coherence parameter, K is the spatiotemporal speckle contrast, and T / τ c The blood flow velocity index is for speckled patterns.

[0100] In the third implementation, the system coherence parameters must first be determined. Regarding the acquisition of the speckle contrast in the static speckle image, a scattering sheet or a material with a scattering effect can be used; this invention does not limit this. Once the system coherence parameters are determined, assuming the erythrocyte scattering type is 1, the spatiotemporal speckle contrast can be determined after acquiring multiple frames of dynamic speckle images. Then, based on the spatiotemporal speckle contrast and the system coherence parameters, the spatiotemporal distribution map of blood perfusion can be determined.

[0101] Specifically, S320, obtaining the spatiotemporal distribution map of blood perfusion in the preprocessed area based on the spatiotemporal distribution map of blood perfusion and the three-dimensional location information includes:

[0102] S321. The three-dimensional position information is correspondingly attached to each pixel of the spatiotemporal distribution map of blood perfusion to obtain a spatiotemporal distribution map of blood perfusion with three-dimensional position information.

[0103] The spatiotemporal distribution map of blood perfusion is represented as a matrix. Three-dimensional location information can be added to each pixel of the spatiotemporal distribution map of blood perfusion using programming techniques to obtain a spatiotemporal distribution map of blood perfusion with three-dimensional location information.

[0104] It should be noted that in the spatiotemporal distribution map of blood perfusion, each matrix element value is the blood perfusion value corresponding to that location. This value is compared with the value specified by the gold standard in medicine, i.e., the preset blood perfusion threshold. When the value is less than the medical standard value, the location is determined to be an abnormal point. The region to be processed determination module traverses each matrix element in the spatiotemporal distribution map of blood perfusion to form an abnormal point matrix, which is the region to be processed.

[0105] This invention also provides a device for observing myocardial blood perfusion patterns, comprising an electrocardiogram (ECG) monitoring device, a laser speckle blood flow imaging module 1, a lidar three-dimensional imaging module 2, a laser projection navigation module 3, and a control system. The ECG monitoring device is used to acquire ECG signals (R-waves); the laser speckle blood flow imaging module 1 is used to acquire dynamic speckle images of a pre-processed region on the myocardium when triggered by the R-wave acquired by the ECG monitoring device (i.e., the acquisition of dynamic speckle images by the laser speckle blood flow imaging module 1 is triggered by the R-wave); the lidar three-dimensional imaging module 2 is used to acquire three-dimensional position information of the pre-processed region when triggered by the R-wave acquired by the ECG monitoring device (i.e., the acquisition of three-dimensional position information by the lidar three-dimensional imaging module 2 is triggered by the R-wave); the laser projection navigation module 3 is used to project the region to be processed on the myocardium using laser; the control system includes an image fusion module and a region to be processed determination module. The image fusion module is used to acquire a spatiotemporal distribution map of blood perfusion in the pre-processed region based on the dynamic speckle image and three-dimensional position information of the pre-processed region. The region to be processed determination module is used to determine the region to be processed based on the spatiotemporal distribution map and a preset blood perfusion threshold.

[0106] It should be noted that the laser speckle blood flow imaging module 1 will acquire multiple frames of dynamic speckle images of the area to be processed at high speed under the trigger of the R-wave, and the lidar three-dimensional imaging module 2 will acquire the three-dimensional position information of the preprocessed area under the trigger of the R-wave. The image fusion module calculates the second-order correlation function, blood flow scattering coefficient and system normalization factor of multiple frames of dynamic speckle images according to the dynamic scattered light-laser speckle contrast imaging technology, thereby obtaining the blood flow velocity. The product of the blood flow velocity and the cross-sectional area of ​​the blood vessel is used to obtain the spatiotemporal distribution map of blood perfusion in the area to be processed. For detailed processing procedures, please refer to the aforementioned method and related published literature (Appl. Opt. 60(23), 6837, 2021). This invention will not elaborate further. After obtaining the spatiotemporal distribution map of blood perfusion, the lidar three-dimensional imaging module 2 is then integrated. The acquired 3D location information is registered with the 2D image and 3D depth data, and the texture is mapped and fused. The location information acquired by the LiDAR is appended to each pixel of the spatiotemporal distribution map of blood perfusion using programming statements to obtain a spatiotemporal distribution map of blood perfusion with 3D location information. The unprocessed area determination module pre-sets the blood perfusion threshold. The spatiotemporal distribution map of blood perfusion can be expressed as a matrix, and each matrix element value is the blood perfusion value corresponding to that location. This value is compared with the value specified by the gold standard in medicine, i.e., the preset blood perfusion threshold. When the value is less than the medical standard value, the location is determined to be an abnormal point. The unprocessed area determination module traverses each matrix element in the spatiotemporal distribution map of blood perfusion to form an abnormal point matrix, which is the unprocessed area.

[0107] The device for observing myocardial blood flow perfusion patterns provided by this invention combines three technologies: dynamic scattered light-laser speckle contrast imaging, lidar three-dimensional imaging, and laser projection display. These three optical technologies offer advantages such as no ionizing radiation, non-invasive measurement, and no need for contrast agent injection, achieving sub-micron spatial resolution and millimeter-level penetration depth into biological tissues. Furthermore, the device can display the spatiotemporal evolution of myocardial blood flow perfusion in real time, enabling monitoring and comparison of changes in myocardial blood flow perfusion before and after coronary artery bypass grafting (CABG). This is of great significance for the effective implementation of CABG procedures and the quantitative evaluation of postoperative outcomes.

[0108] Specifically, the laser speckle blood flow imaging module 1 includes a visible light laser 4, a filtering and beam expanding section 5, a dichroic mirror 9, a first beam splitter 10, a second beam splitter 13, and an imaging section 11. The 630-900nm near-infrared laser emitted by the visible light laser 4 is filtered and expanded by the beam expanding section 5, the dichroic mirror 9, and the first beam splitter 10, illuminating a pre-processed area on the myocardium. Dynamically scattered light carrying blood flow information is reflected by the first beam splitter 10, received by the imaging system, and transmitted to the control system. In the technical solution provided by this invention, a 785nm near-infrared laser is preferred. Traditional speckle imaging technology can only measure low-velocity blood flow of approximately tens of mm / s, and can only measure venous blood flow velocities where vibration interference is negligible due to distance from the heart. The laser speckle blood flow imaging module 1 provided by this invention can overcome complex vibration interference such as heartbeat and respiration, and also has a high flow rate measurement capability, with a blood flow rate measurement capability of not less than 650 mm / s.

[0109] Furthermore, the imaging unit 11 includes a combined lens, a narrowband filter, a polarizer, and a high-speed charge-coupled device (CCD). It should be noted that the imaging unit 11 is mounted on a six-dimensional motorized moving platform, and the dynamic speckle size it records is at least twice the pixel size of the high-speed CCD. Specifically, the positions of the narrowband filter and polarizer can be adjusted to record only dynamic speckle images. The imaging unit 11 uses the R-wave of the electrocardiogram acquired by the electrocardiogram monitoring device as a trigger signal to begin acquiring speckle images, and the acquisition frame rate is greater than the reciprocal of the dynamic degeneration time of myocardial tissue. It should also be noted that the operating speed of the laser speckle blood flow imaging module 1 is higher than the rate of external vibration noise. The image bit depth of the laser speckle blood flow imaging module 1 includes 8-bit, 10-bit, 12-bit, or 16-bit. In this embodiment, a 12-bit image depth is preferred, which simultaneously meets the requirements of speckle test accuracy and data volume memory usage.

[0110] Furthermore, the lidar three-dimensional imaging module 2 includes a visible light laser 4, a collimator and homogenizer 12, a third beam splitter, a dichroic mirror 9, and a photodetector 14. The 808-940nm wavelength laser emitted by the visible light laser 4 is irradiated onto the pre-processed area of ​​the myocardium after passing through the collimator and homogenizer 12, the second beam splitter 13, and the dichroic mirror 9. The scattered light carrying the three-dimensional position information of the myocardium passes again through the dichroic mirror 9 and the second beam splitter 13, and is received by the photodetector 14 and transmitted to the control system.

[0111] Furthermore, the laser projection navigation module 3 includes a visible light laser 4, two filtering beam expanders 5, a spatial light modulator 15, a first reflector 16, and a second reflector 17. The control system transmits the location information of the abnormal point to the spatial light modulator 15 and designs a calibration pattern, such as a crosshair, at that location. The 400-700 nm wavelength laser emitted by the visible light laser 4 passes through the filtering beam expander 5 and illuminates the modulated spatial light modulator 15. The reflected light then passes through another filtering beam expander 5, the first reflector 16, and the second reflector 17 in sequence, illuminating the area to be treated. The calibration pattern is positioned in the area to be treated where the blood perfusion volume is below a threshold, thus realizing the intraoperative lesion localization / navigation function. It should be noted that the spatial light modulator 15 includes a digital micro-reflector or a liquid crystal spatial light modulator, and the filtering beam expander 5 can be configured as a free space filtering beam expander or a fiber optic filtering beam expander. In this embodiment, the filtering beam expander 5 includes a first lens 6, a pinhole 7, and a second lens 8.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for observing myocardial perfusion regularity, characterized in that, The method comprises the following steps: acquiring high signal-to-noise ratio dynamic speckle images of a pre-processing region on a myocardium; acquiring three-dimensional position information of the pre-processing region; acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the high signal-to-noise ratio dynamic speckle images and the three-dimensional position information; determining a to-be-processed region in the pre-processing region according to the blood perfusion quantity space-time distribution map and a blood perfusion quantity threshold value; acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the high signal-to-noise ratio dynamic speckle images and the three-dimensional position information comprises the following steps: acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the high signal-to-noise ratio dynamic speckle images; acquiring a blood perfusion quantity space-time distribution map of the pre-processing region with three-dimensional position information according to the blood perfusion quantity space-time distribution map and the three-dimensional position information; acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the high signal-to-noise ratio dynamic speckle images comprises the following steps: setting 6-20 different exposure times according to gradient changes, the value range of each exposure time is 20 μs-100000 μs, 6-20 groups of dynamic speckle images corresponding to different exposure times are acquired, and each group of dynamic speckle images comprises multiple dynamic speckle images; determining a speckle blood flow rate index and acquiring a speckle blood flow rate index distribution matrix according to a parameter fitting algorithm based on the following formula: acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the speckle blood flow rate index distribution matrix and an intravascular diameter area; where K(T, τ c ) is the speckle contrast, v ne is the variance introduced by static speckle, v noise is the variance caused by experimental noise, β is the system coherence parameter, p is the proportion of dynamic speckle in the total speckle, and T / τ c is the speckle blood flow rate index.

2. A method for observing myocardial perfusion regularity, characterized in that, The method comprises the following steps: acquiring high signal-to-noise ratio dynamic speckle images of a pre-processing region on a myocardium; acquiring three-dimensional position information of the pre-processing region; acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the high signal-to-noise ratio dynamic speckle images and the three-dimensional position information; determining a to-be-processed region in the pre-processing region according to the blood perfusion quantity space-time distribution map and a blood perfusion quantity threshold value; acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the high signal-to-noise ratio dynamic speckle images and the three-dimensional position information comprises the following steps: acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the high signal-to-noise ratio dynamic speckle images; acquiring a blood perfusion quantity space-time distribution map of the pre-processing region with three-dimensional position information according to the blood perfusion quantity space-time distribution map and the three-dimensional position information; acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the high signal-to-noise ratio dynamic speckle images comprises the following steps: acquiring a static speckle image speckle contrast to determine a system coherence parameter; acquiring multiple dynamic speckle images to determine a space-time speckle contrast; determining a speckle blood flow rate index and acquiring a speckle blood flow rate index distribution matrix according to the space-time speckle contrast and the system coherence parameter based on the following function: acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the speckle blood flow rate index distribution matrix and an intravascular diameter area; where β is the system coherence parameter, K is the spatiotemporal speckle contrast, T / τ c is the speckle blood flow rate index.

3. The method of observing myocardial perfusion rules of claim 1 or 2, wherein, acquiring a blood perfusion quantity space-time distribution map of the pre-processing region according to the blood perfusion quantity space-time distribution map and the three-dimensional position information comprises the following steps: The three-dimensional position information is correspondingly attached to each pixel point of the blood perfusion spatiotemporal distribution map, so as to obtain a blood perfusion spatiotemporal distribution map with three-dimensional position information.

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