Image calibrator calibration method, device, system, and storage medium for diagnostic equipment

Abstract

The present application relates to the field of medical image navigation technology and discloses a method for calibrating an image calibrator of a radiological diagnostic device, comprising: placing an image calibrator in the imaging optical path of the radiological diagnostic device and establishing a reference coordinate system for the image calibrator; using a calibration tool to collect a first coordinate of a calibration point in the calibration tool coordinate system, and converting the first coordinate into a second coordinate of the calibration point in the reference coordinate system; obtaining a first transformation relationship between the second coordinate and the design coordinates of the calibration point in the reference coordinate system, and using the first transformation relationship to convert the design coordinates of the marker point in the reference coordinate system into actual coordinates in the reference coordinate system; and calculating the light source position of the radiological diagnostic device and / or performing image registration on the radiological diagnostic device based on the actual coordinates of the marker point. This improves the accuracy of image registration and the reliability of the navigation system. The present application also discloses a device and system for calibrating an image calibrator of a radiological diagnostic device, as well as a computer-readable storage medium.

Description

Technical Field

[0001] The present application relates to the field of medical image navigation technology, for example, to a method and device, system, and computer-readable storage medium for calibrating an image calibrator of a radiological diagnostic device. Background Art

[0002] Currently, image registration is the core technology for accurately linking two-dimensional digital subtraction angiography (DR) images with the three-dimensional intraoperative spatial coordinate system in C-arm surgical navigation systems. Precise image registration maps the two-dimensional images captured by the C-arm to the patient's anatomy and the three-dimensional spatial position of surgical tools in real time, providing surgeons with intuitive intraoperative navigation information. Inadequate registration accuracy can lead to problems such as misaligned surgical tool positioning and misidentification of lesions, directly impacting surgical safety and success rates. Therefore, high-precision image registration is a key foundation for ensuring the reliability and clinical effectiveness of surgical navigation systems.

[0003] The image registration solution of the related technology fixes the image calibrator on the C-arm imaging surface, and then uses the metal ball on it to mark the projection position in the DR image. Combined with the theoretical coordinates preset in the design stage, a geometric mapping relationship between the two-dimensional image and the three-dimensional space coordinate system is established to complete the image registration.

[0004] During the implementation of the embodiments of the present disclosure, it was found that at least the following problems exist in the related art:

[0005] The use of relevant technologies has improved the accuracy of the factors affecting the registration to a certain extent. However, in actual applications, the image calibrator and the reflective array marker are detachable structures. During the installation process, it is easy to introduce slight posture errors due to mechanical matching clearance or manual operation, causing the actual position of the metal ball in the marker coordinate system to deviate from the design value. In addition, the image calibrator with a double-layer metal ball support structure is affected by factors such as gravity, temperature and humidity changes over a long period of time, and the column may be compressed or deformed, destroying the relative position relationship between the two layers of metal balls. The above errors may be directly transmitted to the subsequent image registration and light source position calculation links, resulting in a decrease in registration accuracy and reduced reliability of the navigation system.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0007] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0008] The embodiments of the present disclosure provide a method and apparatus, a system, and a computer-readable storage medium for calibrating an image calibrator of a radiological diagnostic device to improve the accuracy of image registration and enhance the reliability of an image navigation system of the radiological diagnostic device.

[0009] In some embodiments, the image calibrator includes at least one marking layer, on which at least three calibration points and at least three marking points are set; the method includes: placing the image calibrator in the imaging optical path of the radiological diagnostic equipment and establishing a reference coordinate system for the image calibrator; using a calibration tool to collect first coordinates of the calibration points in the calibration tool coordinate system, and converting the first coordinates into second coordinates of the calibration points in the reference coordinate system; obtaining a first transformation relationship between the second coordinates and the design coordinates of the calibration points in the reference coordinate system, and using the first transformation relationship to convert the design coordinates of the marking points in the reference coordinate system into actual coordinates in the reference coordinate system; and calculating the light source position of the radiological diagnostic equipment and / or performing image registration on the radiological diagnostic equipment based on the actual coordinates of the marking points.

[0010] Optionally, converting the first coordinate into the second coordinate of the calibration point in the reference coordinate system includes: converting the first coordinate into a third coordinate in the optical tracking system coordinate system according to a second transformation relationship between the calibration tool coordinate system and the optical tracking system coordinate system; obtaining a third transformation relationship between the reference coordinate system and the optical tracking system coordinate system through the optical tracking system; and converting the third coordinate into the second coordinate using the third transformation relationship.

[0011] Optionally, obtaining a first transformation relationship between the second coordinate and the design coordinates of the calibration point in the reference coordinate system includes: using a preset algorithm to solve the rotation matrix and translation vector of the first transformation relationship based on the second coordinate and the design coordinates of the calibration point in the reference coordinate system; and constructing a transformation matrix of the first transformation relationship based on the rotation matrix and translation vector of the first transformation relationship.

[0012] Optionally, using the calibration tool to collect first coordinates of the calibration points in the calibration tool coordinate system includes: using the calibration tool to collect first coordinates of the calibration points in different marking layers in the calibration tool coordinate system.

[0013] Optionally, the marking point is located within the area surrounded by the calibration points.

[0014] Optionally, the position of the light source of the radiological diagnostic equipment is calculated based on the actual coordinates of the marking point, including: extracting the two-dimensional pixel coordinates of the corresponding marking point from the image of the radiological diagnostic equipment through an image processing algorithm; solving the fourth transformation relationship between the light source coordinate system and the reference coordinate system based on the actual coordinates and the two-dimensional pixel coordinates of the marking point using a preset algorithm; and converting the posture of the light source coordinate system to the optical tracking system coordinate system based on the fourth transformation relationship and the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system to obtain the fourth coordinate of the light source under the optical tracking system.

[0015] Optionally, image registration of the radiological diagnostic equipment is performed based on the actual coordinates of the marker point, including: using the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system to convert the actual coordinates of the marker point into a fifth coordinate in the optical tracking system coordinate system; based on the fifth transformation relationship between the patient coordinate system and the optical tracking system coordinate system, converting the fifth marker point to a sixth coordinate in the patient coordinate system; and establishing a mapping relationship between the image coordinate system and the patient coordinate system based on the sixth coordinate, the position of the light source, and the internal and external parameters of the radiological diagnostic equipment.

[0016] In some embodiments, the apparatus includes: a processor and a memory storing program instructions, wherein the processor is configured to execute the above-mentioned method for calibrating an image calibrator of a radiological diagnostic device when executing the program instructions.

[0017] In some embodiments, the radiological diagnostic equipment image navigation system includes: a radiological diagnostic equipment image navigation system body; and the above-mentioned radiological diagnostic equipment image calibrator calibration device, which is installed on the radiological diagnostic equipment image navigation system body.

[0018] In some embodiments, the computer-readable storage medium stores program instructions, and when the program instructions are executed, the above-mentioned method for calibrating the image calibrator of the radiological diagnostic equipment is executed.

[0019] The image calibrator calibration method and apparatus for radiographic diagnostic equipment, the image navigation system for radiographic diagnostic equipment, and the computer-readable storage medium provided in the embodiments of the present disclosure can achieve the following technical effects:

[0020] An image calibrator is placed in the imaging optical path of a radiographic diagnostic device, and a reference coordinate system for the image calibrator is established. A calibration tool is used to collect a first coordinate of a calibration point in the calibration tool coordinate system, and the first coordinate is converted into a second coordinate of the calibration point in the reference coordinate system. A first transformation relationship between the second coordinate and the design coordinate of the calibration point in the reference coordinate system is then obtained, and the design coordinate of the marker point in the reference coordinate system is converted into an actual coordinate in the reference coordinate system using the first transformation relationship. Finally, based on the actual coordinate of the marker point, the light source position of the radiographic diagnostic device is calculated and / or image registration of the radiographic diagnostic device is performed. By recalibrating the actual value of the marker point in the reference coordinate system before each use, replacing the design value of the marker point in image registration, errors caused by factors such as installation and deformation, long-term use, and environmental changes can be eliminated, image registration and navigation accuracy can be improved, and the reliability of the navigation system can be ensured.

[0021] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily described by corresponding drawings. These exemplary descriptions and drawings do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation. In addition,

[0023] Figure 1 is a schematic structural diagram of an image calibrator for radiological diagnostic equipment provided by an embodiment of the present disclosure;

[0024] Figure 2 This is a schematic structural diagram of a first marking layer of an image calibrator for a radiological diagnostic device provided by an embodiment of the present disclosure;

[0025] Figure 3 This is a schematic structural diagram of a second marking layer of an image calibrator of a radiological diagnostic device provided by an embodiment of the present disclosure;

[0026] Figure 4 is a schematic diagram of coordinate transformation between a calibration tool coordinate system and a reference coordinate system provided by an embodiment of the present disclosure;

[0027] Figure 5 is a schematic diagram of a calibration method for an image calibrator of a radiological diagnostic device provided by an embodiment of the present disclosure;

[0028] Figure 6 It is a schematic diagram of an image calibrator calibration device of a radiological diagnostic device provided by an embodiment of the present disclosure.

[0029] Reference numerals:

[0030] 1: First marking layer; 2: Second marking layer; 3: Column; 4: Installation position; 5: Reflection array; 6: Calibration point; 7: Marking point: 800: Image calibrator calibration device of radiological diagnostic equipment; 801: Processor; 802: Memory; 803: Communication interface; 804: Bus. DETAILED DESCRIPTION

[0031] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The accompanying drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0032] In the description and claims of the embodiments of the present disclosure, as well as in the accompanying drawings, the terms "first," "second," and the like are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to describe the embodiments of the present disclosure herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0033] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to having a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0034] Furthermore, the terms "disposed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a removable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediary, or an internal connection between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this disclosure based on the specific circumstances.

[0035] Unless otherwise stated, the term "plurality" means two or more.

[0036] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0037] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0038] The term "correspondence" may refer to an association relationship or a binding relationship. The correspondence between A and B means that there is an association relationship or a binding relationship between A and B.

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0040] The present disclosure discloses an image navigation system for radiological diagnostic equipment, comprising radiological diagnostic equipment and an image calibrator. The image calibrator comprises at least one reflective array 5 and at least one marking layer, on which at least one calibration point 6 and at least one marking point 7 are disposed. The navigation system also includes a processor, which is electrically connected to the aforementioned electrical components and is used to control their operation.

[0041] In the embodiment of the present disclosure, the radiological diagnostic equipment may be a C-arm, a digital X-ray machine, etc. The marking layer may be one, two, or more. The calibration point 6 or the marking point 7 may be one, two, or other number on each marking layer. Specifically, Figure 1-3 As shown, the image calibrator includes two reflective arrays 5, a first marking layer 1 and a second marking layer 2. The first marking layer 1 and the second marking layer 2 are acrylic plates, and the reflective array 5 is detachably mounted at the mounting position 4 on the opposite side of the first marking layer 1. The first marking layer 1 and the second marking layer 2 are connected by a plurality of columns 3. A plurality of calibration points 6 and a plurality of marking points 7 are provided on the first marking layer 1 and the second marking layer 2. The calibration points 6 are in the form of grooves, and the marking points 7 are in the form of metal balls. When using the image calibrator, the metal ball marking points 7 on the first marking layer 1 are used for image space alignment, and also participate in the calculation of the light source position. The second marking layer 2 is mainly used for light source position calculation. The calibration points 6 are arranged on the outside of the first marking layer 1 and / or the second marking layer 2, and can be specifically arranged at the four diagonal corners of the rectangular marking layer, such as Figure 2 A, B, C, D, and Figure 3 A', B', C', D' in the figure. The marking point 7 is set in the area surrounded by the calibration point 6, as shown in the figure. Figure 2 A, B, C, D, and Figure 3The image calibrator and its reflective array 5 are removable structures, and slight position errors inevitably occur during each installation process, resulting in a discrepancy between the actual position of the metal ball in the reference coordinate system and the designed value. If not calibrated, this error will be transmitted to the subsequent image registration process and light source position calculation. Furthermore, the image calibrator uses a double-layer metal ball marker structure, with the upper and lower layers supported by columns. Due to the influence of gravity, ambient temperature and humidity, the length or stiffness of the columns 3 may be slightly compressed or deformed, thus affecting the relative position of the two metal ball marker layers.

[0042] In order to solve the above problems, the embodiments of the present disclosure propose the following image calibrator calibration method for radiological diagnostic equipment. Any of the following methods can be executed in the image navigation system of the radiological diagnostic equipment, or in a server or terminal device that is communicatively connected to the image navigation system of the radiological diagnostic equipment.

[0043] Combine Figure 5 As shown, the embodiment of the present disclosure provides a method for calibrating an image calibrator of a radiological diagnostic device, comprising:

[0044] S51, placing an image calibrator in an imaging optical path of a radiological diagnostic device, and establishing a reference coordinate system for the image calibrator.

[0045] S52 , using a calibration tool to collect first coordinates of the calibration point in the calibration tool coordinate system, and converting the first coordinates into second coordinates of the calibration point in the reference coordinate system.

[0046] S53 , obtaining a first transformation relationship between the second coordinate and the design coordinates of the calibration point in the reference coordinate system, and using the first transformation relationship to convert the design coordinates of the marking point in the reference coordinate system into actual coordinates in the reference coordinate system.

[0047] S54 , calculating the light source position of the radiological diagnostic device and / or performing image registration on the radiological diagnostic device according to the actual coordinates of the marking point.

[0048] In an embodiment of the present disclosure, an image calibrator is positioned within the imaging optical path of a radiographic diagnostic device. Specifically, the image calibrator is securely fixed to the imaging / receiving surface of the radiographic diagnostic device, ensuring that it completely covers the imaging area with substantially no gaps. A reflective array, such as infrared reflective spheres, is then removably mounted to mounting locations opposite the first marking layer of the image calibrator, such as on either side of the long edge of the first marking layer, to form a complete tracking marker structure. Finally, an optical tracking system, such as an infrared camera, is activated to capture the spatial position of the reflective array in real time. Based on the real-time spatial positions of at least three non-collinear reflective spheres on the reflective array, a reference coordinate system for the image calibrator is dynamically constructed using a rigid body positioning algorithm, such as SVD. The reference coordinate system uses the geometric center of the reflective spheres or a preset reference point as its origin, and the X / Y / Z axes of the coordinate system are determined by the spatial distribution of the reflective spheres. The reference coordinate system is rigidly coupled to the physical structure of the image calibrator and is updated in real time by the optical tracking system as its position changes.

[0049] In the disclosed embodiments, a calibration tool is used to collect the first coordinates of the calibration points in the calibration tool's coordinate system. Specifically, a probe tool with a reflective ball can be used to sequentially contact the groove calibration points on different marking layers of the image calibrator. When the probe tip physically contacts the groove calibration point, the optical tracking system records the first coordinate of that point in the probe coordinate system in real time. In other embodiments, a laser scanner with an integrated reflective ball can also be used to automatically scan the groove calibration points on each marking layer of the image calibrator. Through laser ranging and spatial triangulation, the first coordinate point cloud of the calibration points in the laser scanner's own coordinate system can be directly output.

[0050] In the embodiment of the present disclosure, the first transformation relationship between the second coordinate and the design coordinate of the calibration point in the reference coordinate system is obtained. Specifically, the second coordinate of the calibration point actually measured in the reference coordinate system is input; the theoretical design coordinate of the calibration point preset in the reference coordinate system is loaded; the geometric center position of the actual point set and the design point set is respectively obtained; the optimal rotation angle and translation distance from the actual point set to the design point set are calculated by least squares optimization to ensure that the overall position deviation of all calibration points is minimized; the obtained rotation parameters and translation vectors are combined into a 4×4 rigid transformation matrix, i.e., the first transformation relationship. In other embodiments, the second coordinate of the actual measurement and the theoretical design coordinate of the calibration point preset in the reference coordinate system can also be normalized to eliminate the magnitude difference; the nearest neighbor design point is assigned to each actual point; a temporary rotation matrix and translation vector are calculated based on the current matching point pair; the design point position is adjusted using the temporary transformation and the actual point is re-matched; this is repeated until the change in transformation parameters such as the rotation angle change and / or the translation amount is less than the set threshold; and finally, the converged rotation and translation parameters are combined into the first transformation relationship matrix.

[0051] In the embodiment of the present disclosure, the design coordinates of the marking point in the reference coordinate system are converted into actual coordinates in the reference coordinate system using a first transformation relationship. Specifically, for the first marking layer, the real second coordinates and the design coordinates of the calibration points of this layer in the reference coordinate system are called, and the rigid transformation matrix between the second coordinates and the design coordinates is solved by the SVD algorithm, that is, the first transformation relationship of the first marking layer. Subsequently, the rigid transformation matrix of the first transformation relationship is applied to the design coordinates of all the metal ball marking points in the first marking layer, and the corrected actual coordinates are output in batches. The same operation is performed on the second marking layer simultaneously, and an exclusive rigid transformation matrix is ​​independently calculated based on the calibration points of the second marking layer, that is, the first transformation relationship of the second marking layer, to convert the design coordinates of the metal ball marking points of the second marking layer into actual coordinates. In other embodiments, the first marking layer and / or the second marking layer can be divided into a corresponding number of independent quadrants with the calibration points as boundary points, and in each quadrant, the first transformation relationship (rigid transformation matrix) within each quadrant is calculated based on the second coordinates (actual coordinates) and design coordinates of the internal calibration points; then, dynamic weighting is performed according to the spatial distance between the metal ball marking point and the nearest calibration point. For example, the metal ball marking point close to the compression side quadrant is given a higher translation compensation weight because its corresponding calibration point has a larger measured displacement; finally, the design coordinates of the metal ball marking point are transformed using the first transformation relationship of the quadrant where it is located and the remaining quadrants, and the results are fused according to the calculated weights to output the final actual coordinates. The method dynamically weights the metal ball marker point based on its spatial distance from the nearest calibration point, including: calculating the displacement vector of each calibration point (the difference between the actual coordinates and the designed coordinates), determining the direction of the calibration point with the largest displacement as the main deformation direction; measuring the Euclidean distance from each metal ball marker point to the nearest calibration point, and the projection length of the point in the main deformation direction; assigning a base weight to the metal ball marker point based on the distance value (the closer the distance, the higher the weight), and superimposing a deformation-sensitive weight on top of the base weight (the larger the projection length, the higher the weight). For example, a point less than 10mm away and located in the compression direction projection area can receive a total weight up to 1.5 times that of the adjacent point. Measuring the Euclidean distance from the metal ball marker point to the nearest calibration point and calculating the projection length of the metal ball marker point in the main deformation direction include: calculating the displacement vector from the nearest calibration point to the metal ball marker point; projecting this displacement vector onto the main deformation direction, such as the displacement direction of calibration point A on the compression side of the column. The projection length is the effective component value of the displacement vector in the main deformation direction, which can reflect the degree to which the metal ball marker point is affected by compression.Among them, a basic weight is assigned to the metal ball marker based on the distance value and a deformation-sensitive weight is superimposed on the basic weight, including: calculating the basic weight value based on the straight-line distance from the metal ball marker to the nearest calibration point (the closer the distance, the higher the weight, for example, the weight is 0.8 when the distance is 10 mm, and the weight is 0.2 when the distance is 30 mm); and calculating the deformation-sensitive weight according to the projection length of the metal ball marker in the main deformation direction (the greater the projection length, the greater the weight increase, for example, the weight increases by 0.1 for every 5 mm increase in projection length); and adding the basic weight and the deformation-sensitive weight to obtain the total weight coefficient. Among them, the design coordinates of the metal ball marking point are transformed using the first transformation relationship of the quadrant where it is located and the remaining quadrants, and the final actual coordinates are output according to the calculated weight fusion results, including: using the first transformation relationship of the quadrant where the metal ball marking point is located to transform its design coordinates to obtain the first initial coordinates, and using the first transformation relationships of the remaining quadrants to transform its design coordinates to obtain the corresponding number of second initial coordinates; finally, according to the total weight coefficient fusion, the first initial coordinates are multiplied by the total weight coefficient, and the corresponding number of second initial coordinates are multiplied by one of the corresponding number of (1-total weight coefficient) (for example, assuming there are four quadrants in total, when the total weight is 1.2, the first initial coordinates account for 120%, and the second initial coordinates each account for -6.7% to keep the total 100%), and the actual coordinates of the metal ball marking point are output after summing the products.

[0052] By adopting the image calibrator calibration method of the radiological diagnostic equipment provided by the embodiment of the present disclosure, before each use of the design value of the coordinates of the marker point in the reference coordinate system for light source position and / or image registration, the actual value of the marker point in the reference coordinate system is recalibrated to replace the design value of the marker point in the image registration. This can eliminate errors caused by factors such as installation and deformation, long-term use, and environmental changes, improve image registration and navigation accuracy, and ensure the reliability of the navigation system.

[0053] Optionally, converting the first coordinate into the second coordinate of the calibration point in the reference coordinate system includes: converting the first coordinate into a third coordinate in the optical tracking system coordinate system according to a second transformation relationship between the calibration tool coordinate system and the optical tracking system coordinate system; obtaining a third transformation relationship between the reference coordinate system and the optical tracking system coordinate system through the optical tracking system; and converting the third coordinate into the second coordinate using the third transformation relationship.

[0054] In the disclosed embodiments, an optical tracking system refers to a spatial positioning device based on optical principles, used to capture the spatial position of surgical instruments, patient anatomy, and navigation tools in real time. Its core function is to provide a high-precision dynamic spatial coordinate reference for the surgical navigation system. Specifically, the optical tracking system can be an infrared stereo camera system, which includes infrared cameras and passive reflective spheres. One or more infrared cameras are capable of emitting infrared light of a specific wavelength and receiving reflected signals, while the passive reflective spheres are small reflective spheres mounted on the object to be tracked (such as a probe handle or the reflective array of an image calibrator). The passive reflective spheres are coated with a special material that efficiently reflects the infrared light back to the infrared cameras. In other embodiments, the optical tracking system can also be a laser tracker, which emits a laser beam toward a cooperating target, such as a target scope, mounted on a tool or object. A corner cube within the target scope reflects the laser beam back along its original path to the laser tracker's receiver. The laser tracker measures the angles (horizontal and vertical) of the emitted and returned laser beams and uses laser interferometry or absolute distance measurement techniques to measure the distance to the target scope. Combining angle and distance information, the system can calculate the precise 3D coordinates of the target mirror's center point in the laser tracker's own coordinate system. By moving the target mirror to different points, the 3D coordinates of multiple points can be measured.

[0055] In the embodiment of the present disclosure, Figure 4 As shown, the first coordinate in the calibration tool coordinate system is converted to the second coordinate in the reference coordinate system. Specifically, the calibration tool coordinate system is FProbe, the optical tracking system coordinate system is Fcamera, and the reference coordinate system is FCali. The first coordinate of the calibration point in FProbe can be converted to the third coordinate in Fcamera through the second transformation relationship TcameraToProbe. Then, the third coordinate of the calibration point in Fcamera is converted to the second coordinate in FCali through the third transformation relationship TcameraToCaliRF.

[0056] In the disclosed embodiments, a standard calibration block can be used to calibrate the probe tool before surgery. The spatial relationship between the probe's reflective ball and tip is fixed, generating a second transformation from the calibration tool coordinate system to the optical tracking system coordinate system. During surgery, when the probe contacts the groove calibration point, the optical tracking system captures the position of the probe's reflective ball in real time and converts the first coordinate of the probe tip into a third coordinate in the optical tracking system coordinate system using a second transformation matrix. The optical tracking system simultaneously captures the infrared reflective balls of the reflective array on the image calibrator. Based on the spatial distribution of the reflective balls, the position of the reference coordinate system relative to the optical tracking system coordinate system is calculated in real time to generate a third transformation. Multiplying the third coordinate by the third transformation produces the second coordinate of the calibration point in the reference coordinate system. In other embodiments, the relationship between the laser scanner's reflective balls and the scanning coordinate system can also be pre-calibrated using the second transformation. The laser scanner automatically acquires the first coordinates of all calibration points and converts them into the third coordinates in the optical tracking system coordinate system using the second transformation. Before scanning, the optical system is triggered to momentarily freeze the position of the reflective array, generating a fixed third transformation. Multiplying the third coordinate by the third coordinate relationship produces the second coordinate of all calibration points.

[0057] In this way, by introducing the optical tracking system coordinate system as a conversion intermediary, the first coordinate is first converted to the third coordinate according to the second transformation relationship between the calibration tool coordinate system and the optical tracking system coordinate system. This can unify the spatial data expression of different calibration tools and eliminate the coordinate deviation caused by differences in tool structure. Then, the third transformation relationship between the reference coordinate system and the optical tracking system coordinate system is obtained in real time through the optical tracking system, and the high-precision posture capture capability of the optical tracking system is utilized to ensure the real-time and accuracy of the coordinate system conversion. Finally, the third coordinate is converted to the second coordinate using the third transformation relationship, so that the actual position of the calibration point can be accurately mapped to the reference coordinate system. Through the bridge role of the optical tracking system, the mechanical error of the calibration tool itself is effectively isolated. At the same time, the high-frequency, high-precision posture feedback characteristics of the optical tracking system are utilized to significantly improve the accuracy and robustness of the calibration point coordinate conversion, thereby laying a reliable data foundation for the subsequent solution of the first transformation relationship and the correction of the actual coordinates of the marker point.

[0058] Optionally, obtaining a first transformation relationship between the second coordinate and the design coordinates of the calibration point in the reference coordinate system includes: using a preset algorithm to solve the rotation matrix and translation vector of the first transformation relationship based on the second coordinate and the design coordinates of the calibration point in the reference coordinate system; and constructing a transformation matrix of the first transformation relationship based on the rotation matrix and translation vector of the first transformation relationship.

[0059] In this way, by using a preset algorithm, such as the SVD rigid registration algorithm, to solve the rotation matrix and translation vector of the first transformation relationship based on the second coordinates and the design coordinates of the calibration points in the reference coordinate system, it is possible to accurately separate the rotation and translation components in the spatial pose deviation, thereby specifically characterizing the nonlinear offset caused by assembly errors or structural deformation. The transformation matrix of the first transformation relationship is constructed based on the rotation matrix and translation vector, forming a complete 4×4 homogeneous transformation relationship, ensuring that the conversion process from the design coordinates of the marker points to the actual coordinates strictly complies with the rigid body motion constraints. Mathematical decomposition effectively reduces the difficulty of solving complex pose errors. At the same time, the robustness of the preset algorithm, such as the stability of SVD against noisy data, is utilized to significantly improve the calculation accuracy and reliability of the first transformation relationship, providing strict mathematical guarantees for dynamically correcting the actual spatial position of the marker points and eliminating the systematic deviation between the theoretical design value and the actual physical structure.

[0060] Optionally, using the calibration tool to collect first coordinates of the calibration points in the calibration tool coordinate system includes: using the calibration tool to collect first coordinates of the calibration points in different marking layers in the calibration tool coordinate system.

[0061] In the disclosed embodiment, a probe tool with an infrared reflective ball can be used to maintain the probe posture approximately vertical, such as with an inclination angle of ≤5°, and contact the groove calibration point of the first marking layer. The optical tracking system captures the position of the probe reflective ball in real time and records the first coordinate of the calibration point in the probe coordinate system. The probe is then raised to the second marking layer, and the first coordinate of the calibration point is collected in the same way. Through independent layered collection, the data of the first marking layer and the second marking layer are separated, providing independent inputs for the subsequent layered calculation of the transformation matrix. At the same time, the physical contact mechanism avoids the interference of the deformation of the image calibrator column on the single acquisition. In other embodiments, a line laser scanner can also be used to horizontally emit a laser beam to scan the surface of the first marking layer, automatically identify the calibration points based on the sudden change in groove depth, and batch output the first coordinates of the calibration points in the scanner coordinate system. The line laser scanner then automatically adjusts the laser elevation angle according to the preset layer height parameters (including the column deformation allowance), performs the same scan on the second marking layer, and outputs the first coordinates. Non-contact layered scanning avoids micro-deformation errors caused by probe compression, and automatically compares the measured layer spacing with the theoretical value (if the deviation is >0.3mm, a deformation warning is triggered), directly linking to the detection needs of column compression defects.

[0062] In this way, the image calibrator uses a multi-layer marker layer design, such as a double-layer metal ball structure. Due to assembly errors, gravity, or environmental factors such as temperature and humidity changes, relative displacement or micro-deformation, such as column compression, may occur between the layers, causing the actual positions of the calibration points and markers in the reference coordinate system to deviate from the theoretical values. If only the calibration points of a single marker layer are collected, the inter-layer deformation error cannot be fully reflected. However, collecting calibration points from all layers can cover the overall structural deviation. Therefore, by using a calibration tool such as a probe to collect the first coordinates of the calibration points of different marker layers (such as groove points A, B, C, D, A', B', C', D') in the calibration tool coordinate system, the actual three-dimensional structural state of the image calibrator can be fully captured. By acquiring calibration point data from different layers, the independent transformation relationship between each marking layer and the reference coordinate system can be calculated separately (such as the first transformation relationship TCaliToL1 from the first marking layer coordinate system FL1 to the reference coordinate system, and the first transformation relationship TCaliToL2 from the second marking layer coordinate system FL2 to the reference coordinate system), so as to accurately correct the inter-layer posture offset and ensure that when the design coordinates of the marking points are subsequently converted into actual coordinates, the errors introduced by assembly and deformation are effectively eliminated, the accuracy of light source position calculation and image registration is improved, and the reliability of the navigation system and intraoperative consistency are enhanced.

[0063] Optionally, the marking point is located within the area surrounded by the calibration points.

[0064] In the disclosed embodiment, in the second marking layer, the calibration points are located at the four corners of the rectangle to form a boundary area. The marking points can be arranged radially with the origin of the marking layer coordinate system as the center, where some marking points extend diagonally to near the midpoint of the boundary, and some marking points are distributed in the center area of ​​the rectangle. The above distribution ensures that all marking points are located inside the rectangle enclosed by the calibration points and can be at least 10 mm away from the boundary. Even if the column compression causes the layer to tilt, the marking points are still within the deformation constraint range of the calibration points, so that the rigid transformation calculation is not interfered by edge distortion. In the first marking layer, the calibration points define the rectangular area, and the marking points are divided into a central area, a transition area, and a boundary buffer area according to their function. The central area can be a 5×5 high-density grid to participate in light source calculations. The transition area can be a sparse dot matrix surrounding the center, which can be used for image registration. There are no marking points within 15 mm of the boundary buffer area from the calibration point. The density gradient is used to avoid boundary effects and ensure that when the column deforms, such as local subsidence, the high-weight center point is always in the stable constraint core area of ​​the calibration point.

[0065] In the disclosed embodiment, the calibration points may be distributed at the four diagonal corners of the marking layer to form a rectangular boundary area. The marking points are arranged in an equidistant grid array inside the rectangle. All marking points are located within the polygonal area enclosed by the calibration points, ensuring that the rigid transformation matrix calculated by the calibration points can evenly cover all marking points, avoiding coordinate conversion errors caused by boundary extrapolation. When the image calibrator column is compressed by gravity and causes the upper layer to tilt, the calibration points of the marking layer are displaced to form a non-rectangular quadrilateral area, and although the marking points are offset as the layer deforms, they remain within the area defined by the calibration points. In this state, the area enclosed by the calibration points dynamically reflects the current physical deformation, so that the actual coordinate correction result of the marking point is strictly consistent with the deformed structure, blocking the column compression error from being transmitted to the alignment link.

[0066] In this way, the calibration points are distributed around the marking layer to form a spatial boundary. When the calibration tool collects its coordinates and establishes a rigid transformation relationship in the reference coordinate system, if the marking points exceed this boundary area, especially when the calibrator undergoes non-uniform deformation, its coordinate transformation is susceptible to extrapolation errors. Figure 2 、 Figure 3 The metal balls in the image are all located within the rectangle formed by the groove points. The boundaries formed by the calibration points provide strong spatial constraints on the internal markers, ensuring that the rigid transformation matrix (solved using algorithms such as SVD) evenly covers all markers, avoiding local deformation-amplifying conversion errors. Furthermore, when micro-compression or bending of the pillars causes relative displacement between layers, the markers located within the subspace defined by the calibration points more accurately reflect the actual physical state of the local structure, ensuring that the corrected actual coordinates of the markers are strictly consistent with the current assembly and deformation state. This prevents errors from being transmitted to the light source calculation and image registration stages, ultimately improving the accuracy and reliability of the intraoperative navigation system.

[0067] Optionally, the position of the light source of the radiological diagnostic equipment is calculated based on the actual coordinates of the marking point, including: extracting the two-dimensional pixel coordinates of the corresponding marking point from the image of the radiological diagnostic equipment through an image processing algorithm; solving the fourth transformation relationship between the light source coordinate system and the reference coordinate system based on the actual coordinates and the two-dimensional pixel coordinates of the marking point using a preset algorithm; and converting the posture of the light source coordinate system to the optical tracking system coordinate system based on the fourth transformation relationship and the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system to obtain the fourth coordinate of the light source under the optical tracking system.

[0068] In the disclosed embodiments, an image processing algorithm is used to extract the two-dimensional pixel coordinates of corresponding marker points from images obtained by a radiological diagnostic device. Specifically, the images acquired by the radiological diagnostic device are preprocessed, subjected to Gaussian filtering for noise reduction, and then segmented using adaptive thresholding to separate the highlighted metal ball region from the background. A Hough circle detection algorithm is then applied to identify all circular marker points in the image, for example, filtering artifacts based on a preset radius range and a roundness threshold for the metal balls. Finally, the two-dimensional pixel coordinates of the center of each metal ball in the image coordinate system are output. This can be applied to ideal imaging conditions where the metal ball projections have no overlap and high contrast. In other embodiments, when the image calibrator is tilted, resulting in overlapping projections of the metal ball marker points on the first and second marker layers, a morphological top-hat transform can be performed to enhance local contrast and highlight the edges of the adhesion region. The adhesion spots are then segmented using a watershed algorithm based on a distance transform, for example, by calculating a distance map of the binary image and using the local maximum as the seed point to segment the adhesion region. Finally, the centroid of each segmented region is calculated as the two-dimensional pixel coordinate of the marker point.

[0069] In the disclosed embodiment, a preset algorithm is used to solve the fourth transformation relationship between the light source coordinate system and the reference coordinate system based on the actual coordinates and two-dimensional pixel coordinates of the marker point. Specifically, the EPnP efficient closed-form solution can be used, and the actual coordinates of the calibrated marker point and its two-dimensional pixel coordinates in the image are input; based on the pinhole camera model of the radiological diagnostic equipment, an overdetermined equation is constructed to map the three-dimensional point to the two-dimensional plane through the projection matrix, minimizing the reprojection error; the EPnP algorithm is used to represent the three-dimensional point as a weighted sum of four control points, and after converting it into a linear system of equations, the rotation matrix and translation vector are directly solved through singular value decomposition, i.e., the fourth transformation relationship. In other embodiments, the RANSAC robust iterative method can also be used. When the metal ball projection is blocked by bones or instruments, resulting in coordinate anomalies, a minimum point set is randomly selected and a temporary transformation matrix is ​​solved using PnP; the reprojection error is calculated, and points with an error less than a set pixel are marked as inliers; the maximum inlier set optimization is repeated several times to retain the transformation matrix with the most inliers; based on the inlier set, the Levenberg-Marquardt algorithm is used for nonlinear optimization to output a high-precision fourth transformation relationship.

[0070] In the disclosed embodiment, based on the fourth transformation relationship and the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system, the pose of the light source coordinate system is transformed to the optical tracking system coordinate system, thereby obtaining the fourth coordinate of the light source in the optical tracking system. Specifically, the fourth transformation relationship may represent the pose matrix from the light source coordinate system to the reference coordinate system; at the same time, the third transformation relationship output in real time by the optical tracking system represents the transformation from the reference coordinate system to the optical tracking system coordinate system. By calculating the product of the third transformation relationship and the fourth transformation relationship, a sixth transformation relationship can be obtained. The sixth transformation relationship is used to transform the light source coordinates in the light source coordinate system to the optical tracking system coordinate system, thereby obtaining the fourth coordinate of the light source in the optical tracking system coordinate system. In other embodiments, the fourth transformation relationship may also be decomposed to extract the rotation matrix Rsc and translation vector tsc of the fourth transformation relationship; the light source position is mapped from the reference coordinate system to the optical tracking system coordinate system: tcamera = RcameraToCali*tsc + tcameraToCali, where RcameraToCali / tcameraToCali is the inverse matrix decomposition parameter of TcameraToCaliRF. The combination RcameraToCali×Rsc is a rotation matrix, and tcamera is a translation vector to form the fourth coordinate of the light source in the optical tracking system coordinate system.

[0071] In this way, the two-dimensional pixel coordinates of the marker points are extracted from the image of the radiological diagnostic device through an image processing algorithm. Combined with the actual coordinates of the marker points obtained after calibration in the reference coordinate system, a preset algorithm, such as PnP, is used to directly solve the fourth transformation relationship between the light source coordinate system and the reference coordinate system. This can avoid the systematic deviation caused by the traditional method's reliance on theoretical design values. Based on the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system, the fourth transformation relationship is converted to the fourth coordinate of the output light source in the optical tracking system coordinate system, so that the light source position data is consistent with the intraoperative navigation system coordinate system, avoiding the accumulation of errors in multiple coordinate system conversions. This ensures that the light source position calculation results are directly related to the patient's anatomical space and the real-time positioning data of the surgical tools, thereby improving the C-arm image registration and navigation accuracy.

[0072] Optionally, image registration of the radiological diagnostic equipment is performed based on the actual coordinates of the marker point, including: using the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system to convert the actual coordinates of the marker point into a fifth coordinate in the optical tracking system coordinate system; based on the fifth transformation relationship between the patient coordinate system and the optical tracking system coordinate system, converting the fifth marker point to a sixth coordinate in the patient coordinate system; and establishing a mapping relationship between the image coordinate system and the patient coordinate system based on the sixth coordinate, the position of the light source, and the internal and external parameters of the radiological diagnostic equipment.

[0073] In the disclosed embodiment, the third transformation relationship output in real time by the optical tracking system, i.e., the pose matrix of the reference coordinate system relative to the optical tracking system coordinate system, is used to batch-convert the actual coordinates of the marker points in the reference coordinate system into the fifth coordinates in the optical tracking system coordinate system. Then, through the fifth transformation relationship calibrated before surgery, such as the pose of the reflective ball on the patient reference frame in the optical tracking system coordinate system, the fifth coordinates are uniformly converted into the sixth coordinate in the patient coordinate system, so that the position of the metal ball is directly associated with the patient's skeletal anatomical structure. Finally, combined with the known fourth coordinate of the light source in the optical tracking system coordinate system, the internal parameters (focal length, distortion parameters) and external parameters (the geometric relationship between the light source and the image plane) of the radiological diagnostic equipment, a perspective projection mapping model from the image coordinate system to the patient coordinate system is established to achieve real-time dynamic alignment of the two-dimensional image and the three-dimensional patient space during surgery. In other embodiments, the fifth transformation relationship can also be updated in real time through the optical tracking system, such as the new position of the patient reference frame, to ensure that the conversion from the fifth coordinate to the sixth coordinate is synchronized with the current anatomical position; then the sixth coordinate of the marker point, the real-time position of the light source, and the geometric parameters (internal reference / external reference) of the radiological diagnostic equipment are input into the perspective projection algorithm to reconstruct the mapping relationship between the image coordinate system and the patient coordinate system; if the registration residual is greater than the set value, the recalibration process is automatically triggered.

[0074] In this way, the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system is used to convert the actual coordinates of the marker point in the reference coordinate system into the fifth coordinate in the optical tracking system coordinate system, ensuring that the spatial position of the marker point is synchronized with the intraoperative navigation system in real time. Through the fifth transformation relationship between the patient coordinate system and the optical tracking system coordinate system, such as the calibration results of the patient reflectance array, the fifth coordinate is converted to the sixth coordinate in the patient coordinate system, directly linking the marker point position to the patient's anatomical structure. Finally, based on the sixth coordinate, the fourth coordinate, and the internal and external parameters of the radiological diagnostic equipment, a mapping relationship between the image coordinate system and the patient coordinate system is established. By unifying the data source (the actual coordinates after calibration) and the real-time coordinate system conversion chain, theoretical design value errors and multi-link conversion deviations can be eliminated, ensuring the precise dynamic association between the two-dimensional image and the three-dimensional anatomical space, and improving the accuracy and reliability of intraoperative navigation positioning.

[0075] Combine Figure 6As shown, an embodiment of the present disclosure provides an image calibrator calibration device 800 for radiological diagnostic equipment, comprising a processor 801 and a memory 802. Optionally, the device may further include a communication interface 803 and a bus 804. The processor 801, communication interface 803, and memory 802 may communicate with each other via bus 804. The communication interface 803 may be used for information transmission. The processor 801 may invoke logic instructions in the memory 802 to execute the image calibrator calibration method for radiological diagnostic equipment described in the above embodiment.

[0076] In addition, the logic instructions in the memory 802 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0077] Memory 802, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of the present disclosure. Processor 801 executes the program instructions / modules stored in memory 802 to perform functional applications and data processing, thereby implementing the image calibrator calibration method for radiographic diagnostic equipment in the above-described embodiments.

[0078] The memory 802 may include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on the use of the terminal device. Furthermore, the memory 802 may include high-speed random access memory and non-volatile memory.

[0079] The embodiment of the present disclosure provides an image navigation system for radiological diagnostic equipment, comprising: a radiological diagnostic equipment image navigation system body, and the image calibrator calibration device 800 of the radiological diagnostic equipment mentioned above. The image calibrator calibration device 800 of the radiological diagnostic equipment is installed in the image navigation system body of the radiological diagnostic equipment. The installation relationship described here is not limited to placement inside the image navigation system of the radiological diagnostic equipment, but also includes installation connections with other components of the image navigation system of the radiological diagnostic equipment, including but not limited to physical connections, electrical connections or signal transmission connections, etc. Those skilled in the art can understand that the image calibrator calibration device 800 of the radiological diagnostic equipment can be adapted to a feasible radiological diagnostic equipment image navigation system body, thereby realizing other feasible embodiments.

[0080] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned method for calibrating an image calibrator of a radiological diagnostic device.

[0081] The technical solutions of the embodiments of the present disclosure may be implemented in the form of a software product, which is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present disclosure. The aforementioned storage medium may be a non-transitory storage medium, including: a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, an optical disk, or other media capable of storing program code.

[0082] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible variations. Unless expressly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. Moreover, the terms used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and claims, the singular forms "a", "an" and "the" are intended to also include the plural forms unless the context clearly indicates otherwise. Similarly, the term "and / or" as used in this application means any and all possible combinations of one or more of the associated listings. In addition, when used in this application, the term "comprise" and its variations "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. In the absence of further restrictions, an element defined by the sentence "comprising a..." does not exclude the presence of other identical elements in the process, method or device that includes the element. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments can be referenced to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can be referred to the description of the method part.

[0083] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present disclosure. The technicians will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0084] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices and equipment) can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units may be merely a logical functional division. In actual implementation, other divisions may be used, such as combining or integrating multiple units or components into another system, or omitting or disabling some features. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be through interfaces, indirect couplings or communication connections between devices or units, and may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of these units may be selected to implement the embodiments according to actual needs. Furthermore, the functional units in the disclosed embodiments may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0085] The flowcharts and block diagrams in the accompanying drawings show the possible implementation architectures, functions and operations of the systems, methods and computer program products according to the embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment or part of the code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical functions. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, or they can sometimes be executed in the opposite order, which can depend on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, or they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A method for calibrating an image calibrator of a radiological diagnostic device, characterized in that: The image calibrator includes at least one marking layer, on which at least three calibration points and at least three marking points are set; the method includes: Placing an image calibrator in an imaging optical path of a radiological diagnostic device and establishing a reference coordinate system for the image calibrator; Using a calibration tool to collect a first coordinate of the calibration point in a calibration tool coordinate system, and converting the first coordinate into a second coordinate of the calibration point in a reference coordinate system; Obtaining a first transformation relationship between the second coordinate and the design coordinates of the calibration point in the reference coordinate system, and using the first transformation relationship to convert the design coordinates of the marking point in the reference coordinate system into actual coordinates in the reference coordinate system; Calculating the light source position of the radiological diagnostic device and / or performing image registration on the radiological diagnostic device according to the actual coordinates of the marking points; Among them, the position of the light source of the radiological diagnostic equipment is calculated according to the actual coordinates of the marking point, including: extracting the two-dimensional pixel coordinates of the corresponding marking point from the image of the radiological diagnostic equipment through an image processing algorithm; using a preset algorithm to solve the fourth transformation relationship between the light source coordinate system and the reference coordinate system according to the actual coordinates and the two-dimensional pixel coordinates of the marking point; according to the fourth transformation relationship and the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system, the position of the light source coordinate system is converted to the optical tracking system coordinate system to obtain the fourth coordinate of the light source under the optical tracking system.

2. The method according to claim 1, characterized in that Converting the first coordinate into the second coordinate of the calibration point in the reference coordinate system includes: Converting the first coordinate to a third coordinate in the optical tracking system coordinate system according to a second transformation relationship between the calibration tool coordinate system and the optical tracking system coordinate system; Acquire a third transformation relationship between the reference coordinate system and the optical tracking system coordinate system through the optical tracking system; Use the third transformation relationship to transform the third coordinate into the second coordinate.

3. The method according to claim 1, characterized in that Obtaining the first transformation relationship between the second coordinate and the design coordinate of the calibration point in the reference coordinate system includes: According to the second coordinates and the design coordinates of the calibration point in the reference coordinate system, a preset algorithm is used to solve the rotation matrix and translation vector of the first transformation relationship; A transformation matrix of the first transformation relationship is constructed according to the rotation matrix and the translation vector of the first transformation relationship.

4. The method according to claim 1, wherein Use the calibration tool to collect the first coordinates of the calibration point in the calibration tool coordinate system, including: Use the calibration tool to collect the first coordinates of the calibration points in different marking layers in the calibration tool coordinate system.

5. The method according to claim 1, wherein The marked point is located within the area enclosed by the calibration points.

6. The method according to any one of claims 1 to 5, characterized in that Image registration of radiological diagnostic equipment is performed based on the actual coordinates of the markers, including: Using the third transformation relationship between the optical tracking system coordinate system and the reference coordinate system, the actual coordinates of the marker point are converted into fifth coordinates in the optical tracking system coordinate system; According to a fifth transformation relationship between the patient coordinate system and the optical tracking system coordinate system, the fifth coordinate is converted into a sixth coordinate in the patient coordinate system; A mapping relationship between the image coordinate system and the patient coordinate system is established based on the sixth coordinate, the light source position, and the internal and external parameters of the radiological diagnostic equipment.

7. A calibration device for an image calibrator of a radiological diagnostic device, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to execute the image calibrator calibration method of the radiological diagnostic equipment according to any one of claims 1 to 6 when running the program instructions.

8. An image navigation system for radiological diagnostic equipment, characterized in that: include: Radiological diagnostic equipment image navigation system body; The image calibrator calibration device of the radiological diagnostic equipment according to claim 7 is installed in the image navigation system body of the radiological diagnostic equipment.

9. A computer-readable storage medium storing program instructions, characterized in that: When the program instructions are executed, the computer is configured to execute the method for calibrating an image calibrator of a radiological diagnostic device according to any one of claims 1 to 6.

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