In-loop light field projection method and device, storage medium and electronic equipment

Abstract

The application discloses a ring-intra light field projection method and device, a storage medium and an electronic device, and relates to the technical field of medical science. The method comprises the following steps: acquiring three-dimensional space data of a target object; acquiring position data and a field data of a ray source; determining projection control data according to the three-dimensional space data of the target object, the position data and the field data of the ray source, and sending the projection control data to a projection module; and the ray source is arranged in an inner cavity of a ring-shaped gantry, and the projection module is arranged in an outer space of the ring-shaped gantry. According to the application, the projection module projects visible light to the surface of the target object according to the projection control data, and the area of the visible light is consistent with the radiation field generated by the ray source. The application solves the technical problem that it is inconvenient to confirm the positioning and the irradiation area when the ring-shaped accelerator is used.

Description

Technical Field

[0001] This application relates to the field of medical technology, and more specifically, to a method, apparatus, storage medium, and electronic device for projecting light fields within a ring. Background Technology

[0002] In radiotherapy, medical linear accelerators typically project a visible light profile onto the patient's body surface through an internal optical field system that coincides with the radiation field. This is used for pre-treatment positioning verification and confirmation of the irradiation range. Traditional optical field systems utilize a light source and mirrors located inside the collimator to propagate visible light along the beam path, forming an optical field that overlaps with the radiation field.

[0003] However, in closed radiotherapy systems such as ring accelerators, the radiation source and its collimation system need to be enclosed within the ring gantry. The internal space is compact, and it is difficult to install traditional light sources or reflectors in the path of the radiation source, thus making it impossible to achieve traditional light field projection. Some radiotherapy equipment can only eliminate the light field system, causing inconvenience for clinical positioning and confirmation of the irradiation area.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This application provides a method, apparatus, storage medium, and electronic device for projecting light fields within a ring, to at least solve the technical problem of inconvenience in positioning and confirming the irradiation area when using a ring accelerator in the prior art.

[0006] According to one aspect of the embodiments of this application, an in-ring optical field projection method is provided, comprising: acquiring three-dimensional spatial data of a target object; acquiring position data of a ray source and ray field data; determining projection control data based on the three-dimensional spatial data of the target object, the position data of the ray source, and the ray field data, and sending the projection control data to a projection module, wherein the ray source is disposed in the inner cavity of the annular frame, and the projection module is disposed in the outer space of the annular frame, wherein the projection module projects visible light onto the surface of the target object according to the projection control data, and the area where the visible light is located coincides with the ray irradiation field generated by the ray source; acquiring dynamic three-dimensional spatial data of the surface of the target object during the projection of visible light by the projection module, wherein the dynamic three-dimensional spatial data characterizes the surface morphological changes of the target object caused by breathing, heartbeat, or body position movement; updating the projection control data according to the dynamic three-dimensional spatial data, wherein the updated projection control data is used to make the area where the visible light is located follow the morphological changes of the target object surface.

[0007] According to another aspect of the embodiments of this application, an in-ring light field projection device is also provided, comprising: a first acquisition unit for acquiring three-dimensional spatial data of a target object; a second acquisition unit for acquiring position data of a radiation source and radiation field data; a processing unit for determining projection control data based on the three-dimensional spatial data of the target object, the position data of the radiation source, and the radiation field data, and sending the projection control data to a projection module, wherein the radiation source is disposed in the inner cavity of the annular frame, and the projection module is disposed in the outer space of the annular frame, wherein the projection module projects visible light onto the surface of the target object according to the projection control data, and the area where the visible light is located coincides with the radiation field generated by the radiation source; a dynamic acquisition unit for acquiring dynamic three-dimensional spatial data of the surface of the target object during the projection of visible light by the projection module, wherein the dynamic three-dimensional spatial data characterizes the surface morphological changes of the target object caused by breathing, heartbeat, or body position movement; and an updating unit for updating the projection control data according to the dynamic three-dimensional spatial data, wherein the updated projection control data is used to make the area where the visible light is located follow the morphological changes of the target object surface.

[0008] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, which stores a computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located performs the above-described in-ring light field projection method.

[0009] According to another aspect of the embodiments of this application, an electronic device is also provided, including one or more processors and a memory, the memory being used to store one or more programs, wherein when one or more programs are executed by one or more processors, the one or more processors cause the one or more processors to perform the above-described in-ring light field projection method.

[0010] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program or instructions that, when executed by a processor, implement the above-described method for projection of the inner ring light field.

[0011] As described above, firstly, the X-ray source is located within the inner cavity of the ring gantry, while the projection module is positioned in the external space of the ring gantry. This allows the projection module to project visible light onto the target object's surface from the outside, compensating for the limitation of not being able to install a light field system inside the ring accelerator and mitigating the structural constraints of the compact internal space of the enclosed ring gantry, which prevents the installation of traditional light sources and reflectors. Furthermore, since the projection module does not rely on a coaxial optical structure with the X-ray source, there is no need to arrange light field components inside the gantry. By acquiring the three-dimensional spatial data of the target object, the position data of the X-ray source, and the radiation field data, the control system can determine the actual projection contour of the X-ray irradiation field on the target object's surface, thereby determining the projection control data that the projection module can execute. By determining the projection control data, the area where the visible light projected by the projection module is located precisely matches the X-ray irradiation field. Since the user can directly observe the visible light contour corresponding to the X-ray irradiation field on the patient's body surface, the irradiation range and patient positioning can be intuitively confirmed without relying on the internal light field of the equipment. This effectively improves the positioning efficiency and accuracy of irradiation area confirmation during the use of the ring accelerator, thus solving the technical problem of inconvenient positioning and irradiation area confirmation during the use of the existing ring accelerator. Attached Figure Description

[0012] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0013] Figure 1 This is a schematic diagram of an optional in-ring optical field projection method according to an embodiment of this application;

[0014] Figure 2 This is a schematic diagram of an optional projection process of an in-ring light field projection according to an embodiment of this application;

[0015] Figure 3 This is a schematic diagram of an optional in-ring light field projection device according to an embodiment of this application.

[0016] In the picture:

[0017] 1. Circular frame; 2. X-ray source; 3. Projection module;

[0018] 4. Adjustable structure; 5. Body surface positioning module; 6. Target object;

[0019] 7. Target object bearing surface; 81. Target object surface point cloud coordinate system; 82. Beam vertical plane coordinate system; 83. Projection module local coordinate system. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] It should also be noted that the information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, and displayed data) collected in this application are information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of related data all comply with the relevant laws, regulations, and standards of the relevant regions, necessary confidentiality measures have been taken, and they do not violate public order and good morals. Corresponding operation entry points are provided for users to choose to authorize or refuse. For example, this system has interfaces with relevant users or organizations. Before obtaining relevant information, a request to obtain the information needs to be sent to the aforementioned user or organization through the interface, and the relevant information is obtained only after receiving consent from the aforementioned user or organization.

[0023] It should be noted that the information collected in this application (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for display, data used for analysis, etc.) are information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of this data all comply with relevant laws, regulations, and standards, necessary confidentiality measures have been taken, and they do not violate public order and good morals. Corresponding access points are provided for users to choose to authorize or refuse. For example, interfaces are set up between this system and relevant users or organizations, providing users with corresponding access points to choose to agree to or refuse automated decision-making results; if the user chooses to refuse, the process proceeds to the expert decision-making stage.

[0024] According to the embodiments of this application, a control system can be used as the execution subject of the in-ring light field projection method of this application embodiment. The system can be a software system or an embedded system combining software and hardware. Of course, the method execution subject in the embodiments of this application can also be other forms of execution subject, such as devices, equipment, etc. It should be known by those skilled in the art that this application does not particularly limit the specific form of the method execution subject.

[0025] According to an embodiment of this application, an embodiment of an in-ring optical field projection method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0026] Figure 1 This is a schematic diagram of the in-ring optical field projection method according to an embodiment of this application, as shown below. Figure 1 As shown, the method includes the following steps:

[0027] Step S101: Obtain the three-dimensional spatial data of the target object.

[0028] For example, the three-dimensional spatial data of the target object can refer to a set of information characterizing the surface geometry and spatial position of the target object, such as three-dimensional point cloud data or a three-dimensional mesh model. The target object can be, but is not limited to, a human body, animal, or biomimetic tissue model. When the control system executes the in-loop optical field projection method, it can first acquire the three-dimensional spatial data of the target object so that it can subsequently calculate the intersection line between the ray beam and the surface of the target object based on the surface geometry information of the target object. By acquiring the three-dimensional spatial data of the target object in advance, the control system can accurately calculate the actual contour of the ray irradiation field on the body surface even when the laser projection module and the ray source are not concurrent, which helps to improve the accuracy of the optical field simulation and make the projected visible light area precisely consistent with the ray irradiation field.

[0029] In some embodiments, the control system can acquire image data of the target object's surface through a surface positioning module. The control system can then use a stereo vision algorithm to perform stereo matching on the acquired image data, generating point cloud data containing multiple points with three-dimensional coordinates. The control system can then construct a three-dimensional mesh model of the target object's surface based on this point cloud data, serving as three-dimensional spatial data. This method does not rely on contact measurement and can quickly acquire surface geometric information after the target object is positioned.

[0030] In other embodiments, the control system acquires three-dimensional spatial data of the target object using a structured light scanning device. The control system can project a preset structured light pattern, such as stripes or a coded grating, onto the surface of the target object, while simultaneously acquiring deformed structured light images using an image sensor. Based on the degree of deformation of the structured light image, the control system calculates the depth value corresponding to each pixel using the principle of triangulation, generating three-dimensional point cloud data of the target object's surface. This method is suitable for scenarios requiring high spatial resolution and can more precisely describe the local undulations of the target object's surface.

[0031] Step S102: Obtain the location data of the radiation source and the radiation field data.

[0032] For example, the position data of the ray source can refer to the three-dimensional coordinates of the ray source in a unified spatial coordinate system, and the radiation field data of the ray source can refer to the geometric parameters of the ray beam generated by the ray source, including the radiation field shape parameters and radiation field size parameters. When the control system executes the in-loop optical field projection method, it first acquires the position data of the ray source and the radiation field data to determine the starting point of the ray beam based on the ray source position and the direction of the edge rays based on the radiation field data, thereby calculating the intersection line between the ray beam and the surface of the target object. By acquiring the position data of the ray source and the radiation field data in advance, the control system can accurately restore the propagation range of the ray beam in space even when the laser projection module and the ray source are not concurrent, which is beneficial to improving the accuracy of the radiation field contour calculation.

[0033] In some embodiments, the control system can read the location data of the radiation source and the radiation field data from the radiotherapy planning system. The radiotherapy planning system pre-stores the equipment parameters of the ring accelerator, including the installation coordinates of the radiation source within the ring gantry and the radiation field shape (e.g., a polygonal opening formed by a multi-leaf collimator) and radiation field dimensions (e.g., the side length of the radiation field at the isocenter plane) set in the treatment plan. The control system can send query requests to the radiotherapy planning system via a data interface, receive the returned radiation source location coordinates and radiation field parameters, and store them in local storage for subsequent calculations.

[0034] In other embodiments, the control system can acquire the position data and radiation field data of the X-ray source in real time by reading the control parameters of the ring accelerator. During operation, the ring accelerator's control system records the spatial position of the X-ray source (e.g., calculated from the gantry rotation angle and the fixed offset between the X-ray source and the isocenter) and the current state of the collimator opening (e.g., the position of the multi-leaf collimator blades or the opening size of the mandible and maxilla). The control system communicates with the ring accelerator's control system and directly reads these parameters as the X-ray source position data and radiation field data. This method is suitable for scenarios where the X-ray source position or radiation field parameters change during treatment (e.g., changes in radiation field during dynamic rotation or intensity-modulated therapy), facilitating dynamic projection tracking.

[0035] Step S103: Based on the three-dimensional spatial data of the target object, the position data of the ray source, and the ray field data, determine the projection control data and send the projection control data to the projection module. The ray source is set in the inner cavity of the ring frame, and the projection module is set in the outer space of the ring frame. The projection module projects visible light onto the surface of the target object according to the projection control data. The area where the visible light is located is consistent with the ray irradiation field generated by the ray source.

[0036] For example, projection control data can refer to a set of control commands used to drive the projection module to form a specific visible light pattern on the surface of a target object. The projection module is located in the external space of the ring gantry, such as on the ceiling of a treatment room or on a floor support, while the radiation source is located in the internal cavity of the ring gantry. Visible light can be, but is not limited to, a laser, a high-brightness LED beam, or a beam generated by an ultra-high pressure mercury lamp. The control system needs to determine the projection control data based on the three-dimensional spatial data of the target object, the position data of the radiation source, and the radiation field data. It can fully consider the geometric positional differences between the radiation source and the projection module, and convert the contour of the radiation field on the surface of the target object into a scanning trajectory that the projection module can execute through spatial coordinate transformation. By pre-calculating the projection control data, the control system can ensure that the area of ​​visible light projected by the projection module onto the surface of the target object is precisely consistent with the radiation field generated by the radiation source, even when the laser projection module and the radiation source are not co-located, so as to form an external light field system for the ring accelerator.

[0037] In some embodiments, the control system can first convert the three-dimensional spatial data of the target object, the position data of the ray source, and the position data of the projection module into a unified spatial coordinate system. The control system calculates the spatial range of the ray beam based on the position data of the ray source and the radiation field data, and obtains the intersection line between the ray beam and the surface of the target object, thus obtaining the contour data of the visible light region. Based on this contour data and the position of the projection module in the unified spatial coordinate system, the control system calculates the projection direction and scanning path of the laser beam in the projection module through inverse coordinate transformation, generates projection control data containing the coordinates of the scanning points and the scanning sequence, and sends this projection control data to the projection module via a wireless communication module.

[0038] In other embodiments, the control system can pre-calibrate the position data of the radiation source and the projection module in a unified spatial coordinate system, and update the three-dimensional spatial data of the target object in real time. Based on the radiation field parameters set in the radiotherapy planning system, such as the coordinates of the vertices of the opening polygon at the edge of the radiation field formed by the multi-leaf collimator, the control system generates multiple rays emanating from the radiation source and passing through the edge points of the radiation field in the unified spatial coordinate system. The control system calculates the intersection points of each ray with the surface of the target object, and connects all intersection points sequentially to form closed contour data. The control system transforms this contour data to the local coordinate system of the projection module through coordinate transformation, generates projection control data containing a sequence of laser beam deflection angles, and transmits it to the projection module via wired or wireless means, whereby the projection module performs scanning projection.

[0039] In some optional embodiments, acquiring three-dimensional spatial data of the target object includes: the control system acquiring image data of the target object's surface; performing stereo matching of the target object based on the image data of the target object's surface to determine three-dimensional point cloud data of the target object, wherein the three-dimensional point cloud data includes multiple points with three-dimensional coordinates; and determining three-dimensional spatial data of the target object based on the three-dimensional point cloud data, wherein the three-dimensional spatial data characterizes the geometry of the target object's surface.

[0040] For example, the image data of the target object's surface can refer to two-dimensional images of the target object's surface acquired from different angles using image acquisition devices such as binocular cameras. After acquiring the image data of the target object's surface, the control system performs stereo matching on two or more images to calculate the disparity between corresponding pixels, thereby generating three-dimensional point cloud data containing multiple points with three-dimensional coordinates. The control system can use the three-dimensional point cloud data as the three-dimensional spatial data of the target object, which can characterize the geometry of the target object's surface. By acquiring image data first and then performing stereo matching, the control system can quickly obtain the three-dimensional information of the object's surface without contacting it, which is beneficial for improving the efficiency and security of data acquisition.

[0041] In some embodiments, the control system can acquire image data of the target object's surface through a body surface positioning module. The body surface positioning module may include a binocular stereo vision camera, which may include a first camera and a second camera spaced apart. The first and second cameras can simultaneously acquire two two-dimensional images of the same area of ​​the target object. The control system uses a stereo matching algorithm to calculate the disparity of corresponding pixels in the two images and converts the disparity into three-dimensional coordinates based on camera calibration parameters, generating three-dimensional point cloud data. This embodiment can complete three-dimensional reconstruction of the body surface within seconds, which is beneficial for meeting the needs of rapid positioning.

[0042] In other embodiments, the control system can acquire image data of the target object's surface using a structured light scanning device. The control system projects a preset coded structured light pattern onto the target object's surface and uses an image sensor to acquire a deformed structured light image modulated by the target object's surface. Based on the degree of deformation of the structured light pattern and the principle of triangulation, the control system directly calculates the depth value of each pixel, generating three-dimensional point cloud data. This embodiment can obtain higher-density point cloud data, which is beneficial for finely describing the local undulation features of the target object's surface, thereby improving the boundary positioning accuracy of subsequent field contour calculations.

[0043] In some optional embodiments, projection control data is determined based on the three-dimensional spatial data of the target object, the position data of the ray source, and the radiation field data. This includes: the control system can convert the position data of the ray source, the position data of the projection module, and the three-dimensional spatial data to a unified spatial coordinate system; based on the position data of the ray source and the radiation field data, the spatial range of the ray beam is determined, wherein the radiation field data includes radiation field shape parameters and radiation field size parameters, and the spatial range of the ray beam is used to determine the intersection line between the ray beam and the surface of the target object; based on the spatial range of the ray beam, the contour data of the visible light region on the surface of the target object is determined; based on the contour data and the position data of the projection module, the visible light projection path is calculated through inverse coordinate transformation to determine the projection control data.

[0044] For example, a unified spatial coordinate system can refer to a coordinate system in which the three-dimensional spatial data of the ray source, projection module, and target object are all transformed to the same reference frame. The control system aligns all data to the unified spatial coordinate system through coordinate transformation, facilitating subsequent geometric calculations. Based on the position data of the ray source and the radiation field data, the control system determines the spatial range of the ray beam, which may include the starting point of the ray beam, the direction of the edge rays, and the beam boundary. It then calculates the intersection line between the ray beam and the surface of the target object, obtaining the contour data of the visible light region on the target object surface. Based on this contour data and the position data of the projection module, the control system calculates the path that the visible light emitted from the projection module should point to through inverse coordinate transformation, generating projection control data. Using a unified spatial coordinate system facilitates spatial registration between different devices and allows for accurate calculation of the projection path even when the laser source and the ray source are not concentric, improving the geometric accuracy of the optical field simulation.

[0045] Optionally, the control system establishes three coordinate systems: a beam-vertical plane coordinate system where the X-ray source is located, a patient surface point cloud coordinate system with the isocenter point as the origin, and a local coordinate system with the projection module as the origin. The control system pre-calibrates the transformation matrix from the beam-vertical plane coordinate system to the patient surface coordinate system, and the transformation matrix from the patient surface coordinate system to the projection module's local coordinate system. During calculation, the control system can transform the X-ray source's position data and the coordinates of the field edge points from the beam-vertical plane coordinate system to the patient surface coordinate system, obtaining the coordinates of the X-ray source and the field edge points in a unified spatial coordinate system. Based on these coordinates, the control system calculates the intersection point of the X-ray beam and the target object's surface, and then transforms the intersection point coordinates from the patient surface coordinate system to the projection module's local coordinate system, thereby obtaining the projection control data.

[0046] In some embodiments, the control system can pre-store the fixed installation coordinates of the ray source within the annular frame and the installation coordinates of the projection module at its installation location, such as on the ceiling, and transform the installation coordinates of the ray source and the projection module to a coordinate system with the isocenter point as the origin. The control system generates multiple rays originating from the ray source based on the field parameters (e.g., the vertex coordinates of the polygonal edge of the field formed by the multi-leaf collimator), calculates the intersection points of each ray with the surface of the 3D point cloud model of the target object, and forms a closed contour point set. The control system transforms this contour point set to the local coordinate system of the projection module using a rotation and translation matrix, generating projection control data containing the laser deflection angle. This embodiment can utilize a point cloud patch intersection algorithm, which can accurately handle irregular surface shapes and improve the positioning accuracy of the contour boundary.

[0047] In other embodiments, the control system may also employ an iterative nearest-point algorithm to register the 3D spatial data acquired by the binocular phantom positioning module with a pre-stored reference model, thereby quickly obtaining the pose of the target object in a unified spatial coordinate system. Based on the ray source position and field parameters, the control system calculates the projection boundary between the ray beam and the digitally reconstructed image of the target object's surface, generating a 2D contour. The control system then maps this 2D contour to the scanning field of view of the projection module through back projection, calculating the scanning trajectory of the laser beam as projection control data. This embodiment is suitable for scenarios where the target object's surface is occluded or data is missing. By registering the reference model, the integrity of the data is improved, which helps ensure the stability and reliability of the projection control.

[0048] In some optional embodiments, determining the contour data of the visible light region on the surface of the target object based on the spatial range of the ray beam includes: the control system determining the starting point of the ray beam based on the position data of the ray source; determining the edge ray direction of the ray beam based on the ray field data; determining multiple edge rays based on the starting point and the edge ray direction, wherein each edge ray is used to define the outer boundary of the ray beam; calculating the intersection points of each edge ray with the surface of the target object; and determining the contour data of the visible light region on the surface of the target object based on each intersection point, wherein the contour data characterizes the boundary position of the visible light region.

[0049] For example, the starting point of the ray beam can refer to the spatial coordinates of the ray source in a unified spatial coordinate system. These coordinates can be fixed after the ring accelerator is installed. The edge ray directions can refer to the unit direction vectors pointing from the ray source to the vertices of the field boundary, such as the vertices of the field-of-view edge polygon defined by the blades of a multi-leaf collimator. The control system can generate a spatial straight line from the ray source location along each edge ray direction; these spatial straight lines collectively constitute the outer boundary of the ray beam. The control system calculates the intersection points between each spatial straight line and the geometric model of the target object's surface (e.g., a surface reconstructed from a 3D point cloud), and connects all intersection points in their encircling order on the field boundary to form a closed polygon. The vertex coordinates of this closed polygon represent the boundary positions of the visible light region on the target object's surface. By using a ray-by-ray intersection method, the control system can adapt to arbitrarily complex surface shapes, including uneven areas, thereby obtaining accurate projected contour boundaries and improving the geometric accuracy of the light field simulation.

[0050] Optionally, when the control system solves for the intersection of each edge ray with the target object surface, it can use a distance minimization criterion. For example, it can calculate the shortest distance between each point on the ray and the target object surface, and the point where the distance approaches zero is the intersection point. The control system traverses all edge rays, obtains the nearest intersection point corresponding to each edge ray, and connects these intersection points in the order of the ray field edges to form closed contour data.

[0051] In some embodiments, the control system can read the leaf position parameters of the multi-leaf collimator from the radiotherapy planning system, and generate the vertex coordinates of the edge polygon of the radiation field based on the leaf positions, i.e., the projection points of the endpoints of the edge rays on the isocenter plane. The control system emits rays from the ray source location towards each vertex, forming multiple edge rays. Using the 3D point cloud data of the target object, the control system performs ray tracing calculations on each edge ray to find the closest intersection point between each ray and the point cloud surface. After sorting all intersection points clockwise, connecting them yields the contour data of the radiation field on the target object's surface. This embodiment employs a ray tracing algorithm, which can accurately handle complex surface morphologies and improve the positioning accuracy of the contour boundaries.

[0052] In other embodiments, the control system can convert the three-dimensional spatial data of the target object into a triangular mesh model. Based on the ray source location and the edge polygons of the radiation field, the control system generates a set of ray beams originating from the ray source and covering the entire radiation field area, including internal rays and edge rays. The control system calculates the intersection point of each ray with the triangular mesh; for each edge ray, the intersection point closest to the ray source is selected as the contour boundary point. After sorting all boundary points by angle, the control system uses Bézier curves or spline curves to fit and obtain smooth closed contour data. This embodiment, through curve fitting, helps to eliminate the jagged effect caused by discrete sampling points, resulting in a smoother light field projection contour and improved visual effect.

[0053] In some optional embodiments, the visible light projection path is calculated through inverse coordinate transformation based on the contour data and the position data of the projection module to determine the projection control data. This includes: the control system can acquire the position data of the projection module in a unified spatial coordinate system; transform the contour data from the unified spatial coordinate system to the local coordinate system of the projection module to determine the transformed contour data, wherein the local coordinate system is established with the projection module as the origin; determine the scanning trajectory of the visible light beam based on the transformed contour data, wherein the scanning trajectory includes the position coordinates and scanning order of multiple scanning points; and determine the projection control data based on the scanning trajectory of the visible light beam.

[0054] For example, the position data of the projection module in the unified spatial coordinate system can refer to the installation position coordinates of the projection module (e.g., the spatial coordinates of the optical center of the projection module) and the orientation of the projection module (e.g., the direction angle of the projection optical axis of the projection module). The control system can use this position data of the projection module as the basic parameter for coordinate transformation. For example, the control system can transform the obtained contour data (i.e., the three-dimensional coordinates of the boundary points of the ray irradiation field on the surface of the target object) from the unified spatial coordinate system to a local coordinate system with the projection module as the origin. In the local coordinate system, the azimuth and pitch angles of each contour point relative to the projection module can be directly calculated. The control system can generate a scanning trajectory of the visible beam according to the arrangement order of the contour points (e.g., along the circumferential direction of the irradiation field boundary) based on the transformed contour data. This scanning trajectory may include the position coordinates of each scanning point (e.g., deflection angle) and the connection order and movement speed between the scanning points. The control system generates projection control data based on the scanning trajectory, such as instructions including galvanometer deflection angle sequence, scanning speed, laser switch signal, etc., to drive the projection module to project visible light along the trajectory.

[0055] Optionally, the control system employs the following spatial geometric calculation method: First, the coordinates of the X-ray source in the beam-vertical plane coordinate system (i.e., the X-ray source position) and the vertex coordinates of the edge polygon of the radiation field are transformed to the patient's surface coordinate system using a transformation matrix to obtain the X-ray source position and the direction of the edge rays. Then, the control system solves the problem of minimizing the distance between each edge ray and the triangular patch model of the patient's surface to obtain the intersection point. Finally, the control system transforms the coordinates of the intersection point to the local coordinate system of the laser projection module using another transformation matrix to generate projection control data.

[0056] In some embodiments, the control system can read the installation parameters of the projection module from the installation calibration file, including the spatial coordinates of the projection module in a unified spatial coordinate system and three Euler angles, such as pitch, yaw, and roll. The control system can use these parameters—the spatial coordinates of the projection module in the unified spatial coordinate system and the three Euler angles—to construct a transformation matrix from the unified spatial coordinate system to the local coordinate system of the projection module, for example, a 4×4 homogeneous transformation matrix. The control system multiplies the coordinates of all boundary points in the contour data by this transformation matrix to obtain the direction vector of each boundary point in the local coordinate system of the projection module, i.e., the unit vector pointing from the projection module to the boundary point. The control system converts these direction vectors into deflection angles of the galvanometer scanning system, for example, by calculating the horizontal and vertical angles using the arctangent function, and generates a scanning trajectory according to the encirclement order of the boundary points. The control system packages the angular velocity, dwell time, and laser switch commands of the scanning trajectory into projection control data and sends it to the projection module through the communication interface.

[0057] In other embodiments, the control system can employ a scan line filling strategy to optimize the scan trajectory. The control system first projects the converted contour data onto the imaging plane of the projection module, i.e., a virtual plane perpendicular to the projection optical axis, to obtain a two-dimensional contour. The control system then uses a polygon scan line filling algorithm to generate parallel scan line paths within the two-dimensional contour, such as horizontal or vertical linear scans, rather than simply scanning along the contour boundaries. The control system converts the start and end coordinates of each scan line back to the deflection angle in the local coordinate system of the projection module, forming a scan trajectory covering the entire field of view. Based on the scan trajectory, the control system generates projection control data containing multiple scan line segments and laser switching timing. This embodiment is suitable for scenarios requiring uniform illumination of the interior area of ​​the field of view rather than just displaying the boundaries, which is beneficial for improving the visual clarity and uniformity of the visible light pattern.

[0058] Figure 2 A schematic diagram of the projection process of the inner ring light field projection is shown. A radiation source 2 is installed inside the inner cavity of the ring gantry 1 to generate a therapeutic radiation beam. In the external space of the ring gantry 1, the projection module 3 is installed at a location such as the ceiling of the treatment room via an adjustable structure 4. The adjustable structure 4 is used to adjust the spatial position and projection angle of the projection module 3. A body surface positioning module 5 can be fixedly installed. The body surface positioning module 5 can be a binocular stereo vision system, including a first camera and a second camera spaced apart. The first and second cameras are installed above the target object's supporting surface 7 and are located on the left and right sides of the target object 6, respectively, i.e., distributed laterally along the target object. The optical axes of both the first and second cameras are oriented towards the isocentric point area, ensuring that the field of view can completely cover the target object's body surface. The first and second cameras can synchronously acquire images of the target object's surface. The control system uses a stereo matching algorithm to calculate the parallax, generating three-dimensional point cloud data of the target object 6 (placed on the target object's supporting surface 7), and establishing a target object body surface point cloud coordinate system 81 based on this data. The geometric parameters corresponding to the X-ray source 2 are defined in the beam vertical plane coordinate system 82, while the projection module 3 is defined in the projection module local coordinate system 83. During operation, the control system first acquires the three-dimensional point cloud data of the target object's surface through the body surface positioning module 5 and establishes a body surface model; then, based on the position of the X-ray source 2 and the radiation field parameters, it calculates the intersection line between the X-ray beam and the body surface in a unified spatial coordinate system (usually with the isocenter point as the origin) to obtain the radiation field contour; finally, it transforms the contour data from the body surface point cloud coordinate system 81 to the projection module local coordinate system 83 through coordinate transformation, and uses the adjustable structure 4 to adjust the projection module 3 to a suitable pose, so that the projection module 3 projects visible light onto the surface of the target object 6, making the visible light area precisely consistent with the X-ray irradiation field.

[0059] For example, the control system may use the following spatial geometry calculation method to determine the projection control data, which may specifically include the following steps:

[0060] First, the control system establishes three coordinate systems: the beam-vertical plane coordinate system where the X-ray source is located (i.e., the BEV coordinate system), the patient's surface point cloud coordinate system with the isocenter point as the origin (i.e., the unified spatial coordinate system), and the local coordinate system with the projection module as the origin (i.e., the projection module's local coordinate system). The control system pre-calibrates the first transformation matrix from the beam-vertical plane coordinate system to the patient's surface point cloud coordinate system. And the second transformation matrix from the patient's surface point cloud coordinate system to the projection module's local coordinate system. .

[0061] Then, a coordinate system transformation is performed, that is, the control system obtains the position coordinates of the ray source in the beam vertical plane coordinate system. (i.e., the origin of the BEV coordinate system) and the coordinates of several vertices of the polygon at the edge of the shooting field. For example, the vertices of the viewpoint edge polygon formed by a multi-leaf collimator. The control system will use the coordinates of the ray source position. Multiply by the first transformation matrix The coordinates of the X-ray source in the point cloud coordinate system on the patient's body surface are obtained. , can be represented as:

[0062] ;

[0063] The control system will set the vertex coordinates of the firing field edge. Multiply by the first transformation matrix The coordinates of the edge vertex of the shooting field in the point cloud coordinate system on the patient's body surface are obtained. , can be represented as:

[0064] ;

[0065] Next, the intersection point between the ray and the body surface is calculated, i.e., the control system calculates the intersection point based on the coordinates of the ray source. and the vertex coordinates of the field edge Multiple edge rays emanating from the radiation source and passing through the vertices of the radiation field edge are identified. For each edge ray, the control system solves for the ray and the triangular mesh model of the patient's body surface. The intersection points are found by: finding the parameters. Make the point on the ray The square of the distance to the triangular facet on the body surface is minimized, which can be expressed as:

[0066] ;

[0067] in, It can represent the coordinates of the intersection points of each edge ray and the triangular mesh of the target object surface in the point cloud coordinate system of the patient's body surface. These intersection points constitute the boundary points of the radiation field contour on the body surface. This can represent a triangular mesh model of the patient's body surface in a point cloud coordinate system. This model is obtained through a body surface localization module and is used to characterize the three-dimensional geometry of the target object's surface. Indicates the first A triangular facet. This can represent the coordinates of the radiation source in the patient's body surface point cloud coordinate system. It is obtained by multiplying the origin in the beam-vertical plane coordinate system by the first transformation matrix.

[0068] in, This can represent the parametric equations for points on a ray pointing from the ray source to the edge of the radiation field. For example, when the parameters... At that time, the coordinates of the X-ray source in the point cloud coordinate system on the patient's body surface are obtained. ;when At that time, the coordinates of the vertex of the shooting field edge in the point cloud coordinate system on the patient's body surface are obtained. By changing The value of (between 0 and 1) provides the spatial coordinates of any point on the line connecting the ray source to the edge of the radiation field. In calculating the intersection of the ray with the patient's body surface, the control system uses this parametric equation to describe the spatial position of each edge ray, combined with a triangular patch model of the body surface. Find the solution that minimizes the distance between a point on the ray and the body surface. The values ​​are used to determine the coordinates of the intersection point.

[0069] The point where the square of the distance approaches zero is the intersection point. The control system traverses all edge rays and obtains the intersection point corresponding to each edge ray. These intersections are the boundary points of the shooting field contour on the patient's body surface.

[0070] Finally, the coordinates are transformed to the local coordinate system of the projection module. The control system multiplies the boundary point coordinates by the second transformation matrix to obtain the intersection point coordinates in the local coordinate system of the projection module, which can be expressed as:

[0071] ;

[0072] in, It can represent the transformed value of the above intersection point coordinates in the local coordinate system of the projection module such as the laser projection device, and is used to control the laser scanning mechanism to project the laser beam to the corresponding direction.

[0073] The control system determines the direction the laser beam should point based on the coordinates of these intersection points, that is, the direction vector from the origin of the projection module to each intersection point, and generates the laser scanning trajectory according to the order of the intersection points, thereby determining the projection control data.

[0074] Using the aforementioned spatial geometric calculation method, the control system can accurately transform the ray irradiation field from the ray source coordinate system to the projection module coordinate system, and generate a visible light profile on the target object surface that is consistent with the ray irradiation field.

[0075] In some optional embodiments, the projection module is a laser projection module, which includes a laser emitter and a laser scanning mechanism. Sending projection control data to the projection module includes: the control system can send the projection control data to the laser emitter, wherein the laser emitter is used to generate a laser beam; and sending the projection control data to the laser scanning mechanism, wherein the laser scanning mechanism is used to adjust the projection direction of the laser beam so that the laser beam scans the area on the surface of the target object to form visible light.

[0076] For example, a laser projection module can refer to a projection device that uses a laser beam as a light source and controls the beam deflection through a scanning mechanism. A laser emitter generates a high-brightness visible laser beam, and a laser scanning mechanism changes the emission direction of the laser beam. The control system sends projection control data to both the laser emitter and the laser scanning mechanism. The laser emitter can control the timing and power of the laser emission based on brightness or switching timing commands in the projection control data, while the laser scanning mechanism can control the beam deflection path based on angle sequence commands in the projection control data. By sending the control data separately, the control system can independently adjust the laser's on / off state and scanning trajectory, enabling the laser beam to accurately scan the surface of the target object, forming a closed contour or filled area consistent with the irradiation field. This improves the clarity and dynamic response speed of the projected pattern.

[0077] Optionally, the wireless communication module can use wireless local area network, Bluetooth, or other wireless communication methods. The control system can send scanning trajectory data to the laser scanning mechanism through a serial communication interface. This scanning trajectory data includes a series of sequentially arranged deflection angle values, such as horizontal and vertical angles, with each deflection angle value corresponding to the position of a scanning point.

[0078] In some embodiments, the control system can send scanning trajectory data to the laser scanning mechanism via a serial communication interface. This scanning trajectory data may include a series of sequentially arranged deflection angle values, such as horizontal and vertical angles, with each deflection angle corresponding to the position of a scanning point. Simultaneously, the control system sends switching signals to the laser emitter via a digital input / output interface, turning on the laser emitter when the laser scanning mechanism stops at each scanning point and turning it off during the movement of the scanning beam. The control system can employ a vector scanning method, ensuring that the laser beam moves and illuminates only along the boundary of the radiation field contour, forming a single-pixel-width contour line. This embodiment clearly displays the radiation field boundary, facilitating intuitive confirmation of the irradiation range by the user.

[0079] In other embodiments, the control system sends raster scanning parameters, including the lateral scanning range, longitudinal step spacing, and scanning speed, to the laser scanning mechanism, and sends a grayscale modulation signal corresponding to the scanning position to the laser emitter. Based on the filling area information in the projection control data, the control system controls the laser emitter to output a set power when scanning the area inside the projection field, and shuts down the laser emitter or reduces its power when scanning the area outside the projection field. The control system uses a raster scanning method, allowing the laser beam to cover the entire projection area line by line, forming a filling spot with uniform brightness. This embodiment is suitable for scenarios requiring the display of dose distribution within the projection field or auxiliary positioning marks, and is beneficial for improving the richness of projection information.

[0080] In some optional embodiments, the method further includes: the control system may send an adjustment command to the adjustable structure before sending projection control data to the projection module, wherein the adjustment command is used to instruct the adjustable structure to adjust the spatial position and projection angle of the projection module, the spatial position including translation along a first direction, a second direction and a third direction that are perpendicular to each other, and the projection angle including rotation angles about the first direction, the second direction and the third direction.

[0081] For example, the adjustable structure can refer to a mechanical actuator that can change the spatial position and orientation of the projection module, such as a multi-axis displacement stage driven by a stepper motor or a rotary platform driven by a servo motor. The spatial position includes translational amounts along three mutually perpendicular directions: a first direction (horizontal), a second direction (horizontal), and a third direction (vertical). The projection angle includes rotational angles around the first, second, and third directions, such as pitch, yaw, and roll angles. Before sending projection control data, the control system sends adjustment commands to the adjustable structure, adjusting the projection module to an optimal projection position and angle. This facilitates ensuring that the optical axis of the projection module covers the area where the target object is located and that the projection beam forms a suitable incident angle with the surface of the target object. By pre-adjusting the spatial position and projection angle of the projection module, the control system can adapt to installation deviations in different treatment rooms and the irradiation needs of patients of different body types, expanding the applicable installation range of the projection module, reducing the requirements for installation accuracy, and flexibly adjusting the projection direction for patients of different body types in different treatment scenarios, which helps improve the integrity of projection coverage and the geometric fidelity of the light spot.

[0082] In some embodiments, the control system reads the deviation between the current pose and the ideal pose of the projection module from the installation calibration file. Based on this deviation, the control system calculates the required translation along the first, second, and third directions, as well as the required rotation angle around each direction, and generates adjustment commands. The control system sends the adjustment commands to the drive motor in the adjustable structure; for example, the drive motor can be, but is not limited to, a stepper motor, a servo motor, or a piezoelectric motor. The drive motor moves the projection module along a slide rail or rotates it around a rotation axis to the target pose. After adjustment, the control system confirms the correct position via a position sensor before sending subsequent projection control data. This embodiment can automatically complete the pose calibration of the projection module, which helps reduce the workload of manual debugging.

[0083] In other embodiments, the control system calculates the optimal projection angle of the projection module in real time based on the body shape parameters of the target object. The control system acquires three-dimensional spatial data of the target object, such as body width, thickness, and surface curvature, and analyzes the angular distribution between the optical axis of the projection module and the surface normal of the target object. With the optimization goals of maximizing projection sharpness and minimizing projection distortion, the control system calculates the optimal pose of the projection module, including translation and rotation angles, and sends adjustment commands to the adjustable structure to drive the projection module to move to this optimal pose. This embodiment can automatically adapt the projection posture to patients of different body shapes, which is beneficial for maintaining the sharpness and geometric accuracy of the projected pattern during treatment.

[0084] In some embodiments, the adjustable structure can employ various mechanical methods to adjust the pose of the projection module. The driving method of the adjustable structure can be, but is not limited to, electric, pneumatic, or hydraulic drive. For example, the adjustable structure may include a worm gear mechanism and a lead screw slide driven by a motor. Before each treatment begins, the control system automatically calculates the optimal working posture of the projection module based on the target object's body shape parameters and three-dimensional surface data, such as the angle between the projection optical axis and the normal to the target object's surface. The control system sends motion commands to the motor, driving the projection module to move along a preset arc guide rail to the position corresponding to this posture and locking the angle. After adjustment, the control system updates the current position data of the projection module to a unified spatial coordinate system for subsequent projection control data calculations. This embodiment can automatically adapt the projection posture according to the patient's body shape, which helps reduce manual adjustment operations and improves work efficiency. For example, the adjustable structure can be an electrically driven three-axis translation stage, which is driven by a stepper motor or servo motor via a lead screw or belt drive to achieve precise translation of the projection module in the horizontal, vertical, and longitudinal directions. Alternatively, the adjustable structure can be an electrically driven rotary table or electric pan-tilt head, which is driven by a motor via a worm gear mechanism to achieve rotational adjustment of the projection module around three mutually perpendicular directions. Another example is a pneumatically or hydraulically driven multi-axis platform, which uses the extension and retraction of cylinders or hydraulic cylinders to push a linkage mechanism to achieve spatial position adjustment of the projection module, suitable for scenarios requiring rapid response or high thrust.

[0085] Optionally, the projection module can be fixed to the ceiling of the treatment room via a mounting bracket. The mounting bracket has a mounting part that connects to the ceiling and a support structure for supporting the projection module. An adjustable structure is disposed between the mounting bracket and the projection module for adjusting the spatial position and projection angle of the projection module. Before sending projection control data, the control system automatically calculates the optimal working posture of the projection module based on the body shape parameters and three-dimensional surface data of the target object, and sends adjustment commands to the adjustable structure.

[0086] In some optional embodiments, the method further includes: the control system acquiring three-dimensional spatial data of a calibration phantom, wherein the calibration phantom is placed at an isocenter point, the isocenter point representing the intersection of the beam central axis of the X-ray source and the rotation axis of the annular frame; controlling the projection module to project a calibration pattern onto the calibration phantom, wherein the calibration pattern is a visible light pattern with a preset geometry; generating calibration parameters based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom, wherein the deviation represents the difference between the actual projection direction of the projection module and the standard projection direction; and storing the calibration parameters, wherein the calibration parameters are used to correct the projection control data.

[0087] For example, the calibration phantom can refer to a standard object with known geometry and dimensions, such as a cube, sphere, or plate with marked points. The calibration phantom can be placed at an isocenter. The isocenter can be the intersection of the beam center axis of the radiation source and the rotation axis of the ring gantry, and can serve as the reference origin for all spatial coordinates in the radiotherapy system. The control system first acquires the three-dimensional spatial data of the calibration phantom, for example, by scanning the surface of the calibration phantom using a binocular phantom positioning module to obtain a three-dimensional point cloud model of the calibration phantom. The control system controls the projection module to project a visible light pattern of a preset geometry, such as a crosshair, grid, or rectangular border, onto the surface of the calibration phantom. Based on the deviation between the three-dimensional spatial data of the calibration phantom and the actual imaging position of the calibration pattern on the calibration phantom, such as the offset between the center of the pattern and the theoretical center of the phantom, the control system calculates the difference between the actual projection direction of the projection module and the standard projection direction, and generates calibration parameters. The control system stores these calibration parameters for subsequent correction of the projection control data. By pre-executing this calibration process, the control system can compensate for positional and angular errors generated during the installation of the projection module, which helps to improve the consistency between the projection and the radiation field.

[0088] In some embodiments, the calibration phantom can be a flat phantom with multiple highly reflective markers, the coordinates of which in three-dimensional space are known. The control system scans the calibration phantom using a surface positioning module to extract the three-dimensional coordinates of the highly reflective markers as the three-dimensional spatial data of the calibration phantom. The control system controls the projection module to project a grid pattern composed of multiple light points onto the calibration phantom, and uses a camera to capture an image of the projected pattern on the phantom surface. The control system identifies the actual pixel coordinates of the light points in the image and converts the actual pixel coordinates of the light points into three-dimensional spatial coordinates according to the camera calibration parameters. The control system calculates the spatial offset between each actual projected light point and its corresponding theoretical marker point, generating a calibration mapping table, which is a correction matrix from the local coordinates of the projection module to the coordinates of the isocenter point. The control system stores this calibration mapping table as calibration parameters. This embodiment uses a multi-point matching method, which can correct the nonlinear distortion of the projection module and improve the projection accuracy at the edges of a large field of view.

[0089] In other embodiments, the control system employs an automatic iterative optimization method to generate calibration parameters. The control system directs the projection module to project a calibration pattern, such as a crosshair, onto the calibration phantom, while simultaneously acquiring the position of the projected pattern on the phantom's surface in real time via a surface positioning module. The control system calculates the deviation between the current projected position and the theoretical position, automatically adjusting adjustable structures or modifying projection control data based on the deviation to gradually approach the ideal position. When the deviation is less than a preset threshold, the control system stores the currently used correction amount as the final calibration parameter. This embodiment eliminates the need for prior measurement of the projection module's precise installation orientation, automatically completing calibration through closed-loop feedback, which helps reduce installation and debugging difficulty and time costs.

[0090] In some optional embodiments, generating calibration parameters based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom includes: the control system can calculate the spatial offset and attitude deviation angle between the projection module and the isocenter point based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom; wherein the spatial offset characterizes the positional difference between the projection origin of the projection module and the isocenter point in three-dimensional space, and the attitude deviation angle characterizes the angular difference between the actual projection direction of the projection module and the ideal projection direction pointing to the isocenter point; and determine the calibration mapping matrix based on the spatial offset and attitude deviation angle, using the calibration mapping matrix as calibration parameters, wherein the calibration mapping matrix is ​​used to transform the projection control data from the local coordinate system of the projection module to the coordinate system of the isocenter point.

[0091] For example, the spatial offset can refer to the position difference vector between the projection origin of the projection module (i.e., the exit point of the visible light beam) and the isocenter point in three-dimensional space, and can include translation components along the three coordinate axes of the first, second, and third directions. The attitude deviation angle can refer to the angular difference between the actual projection direction of the projection module (i.e., the optical axis direction of the visible light beam) and the ideal projection direction pointing to the isocenter point, including pitch angle deviation, yaw angle deviation, and roll angle deviation. Based on the deviation between the three-dimensional spatial data of the calibration phantom and the actual imaging position of the calibration pattern, the control system can deduce the spatial offset and attitude deviation angle through geometric relationships. The control system constructs a calibration mapping matrix based on the spatial offset and attitude deviation angle, which is used to transform the subsequently calculated projection control data from the local coordinate system of the projection module to the coordinate system of the isocenter point. By obtaining the spatial offset and attitude deviation angle and establishing the calibration mapping matrix during the calibration process, the control system can compensate for the installation and manufacturing errors of the projection module, enabling the projection module to project accurately with the isocenter point as a reference, which is beneficial to improving the overlap between the light field and the ray irradiation field.

[0092] In some embodiments, the control system can use the least squares fitting method to calculate the spatial offset and attitude deviation angle. The control system stores a theoretical 3D model of the calibration phantom, such as a cube of known dimensions, whose geometric center is located at an isocenter. The control system controls the projection module to project an array pattern of multiple light points onto the calibration phantom, and uses a surface positioning module to obtain the actual 3D coordinates of each light point on the phantom surface. The control system establishes a theoretical projection point set for the calibration phantom, i.e., the theoretical position of each light point, with the isocenter as the origin. The control system calculates the rigid transformation matrix between the actual projection point set and the theoretical point set, which may include rotation and translation, and solves for the optimal estimate of the transformation matrix through singular value decomposition. The control system decomposes the rigid transformation matrix into three axial translational components (i.e., spatial offset) and three Euler angle components (i.e., attitude deviation angle), and can construct a calibration mapping matrix accordingly. This embodiment uses a multi-point matching method, which can simultaneously compensate for translation and rotation errors, improving calibration accuracy.

[0093] In other embodiments, the control system employs a step-by-step calibration method to sequentially determine the spatial offset and attitude deviation angle. First, the control system controls the projection module to project a central crosshair onto the calibration phantom. The surface positioning module measures the position of the crosshair intersection on the phantom surface. The control system calculates the coordinate difference between this intersection and the isocenter point in the isocenter point coordinate system, which serves as the spatial offset of the projection module, i.e., the translation correction. After adjusting the position parameters in the projection control data based on this spatial offset, the control system projects a set of concentric circular patterns. The attitude deviation angle is then inferred by measuring the offset of the center of the circular patterns. The control system iterates these two steps repeatedly until the deviation between the projected pattern and the theoretical position is less than a preset threshold. Finally, the final spatial offset and attitude deviation angle are used to construct a calibration mapping matrix. This embodiment exhibits stable step-by-step iterative convergence, which is beneficial for obtaining high-precision calibration results even with limited hardware adjustment range.

[0094] In some optional embodiments, the method further includes: the control system can acquire dynamic three-dimensional spatial data of the surface of the target object during the projection of visible light by the projection module, wherein the dynamic three-dimensional spatial data characterizes the surface morphological changes of the target object caused by breathing, heartbeat or body position movement; and update the projection control data according to the dynamic three-dimensional spatial data, wherein the updated projection control data is used to make the area where the visible light is located follow the morphological changes of the target object surface.

[0095] For example, dynamic three-dimensional spatial data can refer to the surface geometric information of the target object acquired in real time during the projection of visible light by the projection module. This dynamic three-dimensional spatial data can reflect the surface morphological changes of the target object caused by breathing, heartbeat, or body position movement, such as chest rise and fall, abdominal expansion, or limb displacement. While the projection module continuously projects visible light, the control system acquires the dynamic three-dimensional spatial data of the target object at a preset frequency (e.g., 30 times per second). The control system recalculates the intersection line between the X-ray beam and the surface of the target object based on the dynamic three-dimensional spatial data and updates the projection control data. This updated projection control data drives the projection module to adjust the scanning trajectory of the visible beam, so that the area where the visible light is located can follow the morphological changes of the target object's surface in real time. By dynamically acquiring surface data and updating the projection control data in real time, the control system can adaptively compensate for positional deviations caused by the patient's respiratory movements and body position movements during treatment, which helps maintain spatial consistency between the visible light projection area and the X-ray irradiation field and improves the continuous accuracy of radiotherapy positioning.

[0096] In some embodiments, the control system can acquire a dynamic point cloud sequence of the target object's surface in real time via a body surface positioning module. The control system registers point cloud data from adjacent time frames and calculates motion vectors for each region of the target object's surface, such as the displacement velocity and direction of each pixel. Based on the motion vectors, the control system predicts the changing trend of the target object's surface contour at the next moment, corrects the calculated intersection of the ray beam and the body surface in advance, and generates updated projection control data. The control system sends the updated projection control data to the projection module, enabling the laser beam to synchronously complete scanning as it moves to a new position on the target object's surface. This embodiment can compensate for the computational delay of the control system and the mechanical response delay of the projection module, thus improving the real-time performance of dynamic tracking.

[0097] In other embodiments, the control system can synchronously update the timing based on respiratory gating signals or heart rate monitoring signals. The control system acquires the respiratory gating signals of the target subject, such as end-expiratory and end-inspiratory phase markers provided by a breathing belt or infrared tracking system. The control system updates the projection control data only at specific phases of the target subject's respiratory cycle, such as the relatively quiescent period at the end of expiration, while pausing updates or using historical data from the same phase of the previous cycle during periods of vigorous movement. The control system reduces projection jitter caused by rapid movement through phase locking, freezing the visible light pattern at the moment of slowest respiratory motion. This embodiment is suitable for patients with regular respiratory movements, helping to reduce computational load while ensuring the clarity and stability of the projected pattern during quiescent periods.

[0098] In some optional embodiments, acquiring dynamic three-dimensional spatial data of the target object surface includes: the control system can acquire dynamic three-dimensional spatial data at a specific phase of the target object's respiratory cycle based on a respiratory gating signal, wherein the respiratory gating signal is used to identify a specific phase interval between the end-inspiratory phase, the end-expiratory phase, or the end-inspiratory phase and the end-expiratory phase in the target object's respiratory cycle, and the specific phase is the phase in which the surface motion amplitude of the target object is minimal.

[0099] For example, the respiratory gating signal can refer to the phase marker of the respiratory cycle of the target object, generated in real time by external respiratory monitoring devices such as breathing belts, infrared tracking systems, or cameras, used to distinguish the end-inspiratory phase, the end-expiratory phase, and the transition phase between them. Based on the respiratory gating signal, the control system acquires dynamic three-dimensional spatial data at a specific phase of the target object's respiratory cycle. For example, the specific phase could be the end-expiratory phase, when lung movement is minimal and the body surface position is relatively stable. By acquiring data at the moment when body surface movement is most gradual, the control system can obtain three-dimensional information of the body surface with a high signal-to-noise ratio, which helps avoid point cloud blurring or registration failure caused by rapid movement. The control system triggers data acquisition only at this specific phase, which reduces the computational load caused by continuous data acquisition and improves the stability of projection control data updates. This also helps ensure that the visible light pattern is accurately aligned with the target object during the slowest respiratory movement, reducing jitter in the projected pattern.

[0100] In some embodiments, the control system can wirelessly receive gating pulse signals sent by the respiratory monitoring device. When the rising edge of the end-expiratory phase is detected, the control system immediately triggers the surface localization module to simultaneously acquire two images of the target object's surface, and completes stereo matching and 3D point cloud reconstruction within milliseconds to obtain dynamic 3D spatial data at that phase. The control system uses this dynamic 3D spatial data to calculate updated projection control data and sends the projection control data to the projection module, ensuring that the laser profile is updated before the start of the same phase in the next respiratory cycle. This embodiment utilizes the static window at the end of expiration for sampling and calculation, which helps improve the timing accuracy of projection updates.

[0101] In other embodiments, the control system pre-learns the respiratory cycle pattern of the target object and calculates the statistical distribution of body surface displacement between the end of inspiration and the end of expiration. The control system identifies the end-inspiratory and end-expiratory phases based on gating signals and simultaneously acquires dynamic three-dimensional spatial data during these two phases. The control system calculates the difference in the body surface displacement field between the two phases to predict the mid-stage position of respiratory motion, for example, by estimating the body surface shape at any time between the two phases using linear interpolation. Based on the prediction results, the control system continuously projects the same set of control data multiple times within the phase interval with the smallest motion amplitude (e.g., a window lasting 0.5 seconds after the end of expiration), while temporarily shutting off laser projection or reducing brightness in the interval of intense motion. This embodiment is suitable for scenarios where stable synchronization to a single phase is not possible, and it helps to provide a certain degree of real-time update capability while ensuring projection stability.

[0102] In some optional embodiments, the method further includes: the control system can detect the illumination brightness of the environment in which the projection module is located, wherein the illumination brightness characterizes the light intensity of the environment surrounding the projection module; determine a brightness adjustment amount based on the detected illumination brightness, wherein the brightness adjustment amount characterizes the extent to which the light intensity emitted by the projection module needs to be adjusted, and the brightness adjustment amount is positively or negatively correlated with the illumination brightness; and adjust the light intensity emitted by the projection module based on the brightness adjustment amount, wherein the light intensity emitted characterizes the light power density of the visible light emitted by the projection module.

[0103] For example, illumination brightness can refer to the ambient light intensity in the environment where the projection module is located, such as in a treatment room, generated by indoor lighting, a display, or other light sources. The control system detects the illumination brightness and can automatically adjust the output light intensity of the projection module according to changes in ambient light, ensuring that the projected visible light pattern remains clearly visible under different lighting conditions. The control system determines the brightness adjustment amount based on the detected illumination brightness; when the illumination brightness is high, the output light intensity is increased to improve visible light contrast, and when the illumination brightness is low, the output light intensity is decreased to avoid glare or save energy. By automatically adjusting the output light intensity, the control system can maintain a stable visual perception effect of the visible light pattern under different ambient light conditions, which is beneficial to improving the convenience of clinical operation and patient comfort.

[0104] In some embodiments, the control system acquires real-time illumination brightness data via an ambient light sensor mounted on the projection module housing. The ambient light sensor converts the light intensity into an analog voltage signal, which the control system reads and converts into an illuminance value via an analog-to-digital converter. The control system internally stores a luminance mapping table, which defines the output light intensity adjustment coefficients corresponding to different illuminance ranges. The control system can query the mapping table based on the current illuminance value to obtain the brightness adjustment amount and control the drive current of the laser emitter via a pulse width modulation signal to achieve linear adjustment of the output light intensity. This embodiment offers fast response speed, facilitating real-time adaptation to changes in the treatment room lighting.

[0105] In other embodiments, the control system can adaptively adjust based on the visibility feedback of the projected pattern. While the projection module projects a visible light pattern, the control system uses a surface positioning module to acquire an image of the target object's surface and analyzes the contrast or signal-to-noise ratio of the projected pattern area using image processing algorithms. The control system calculates the difference between the current contrast and the preset target contrast and dynamically adjusts the output light intensity using a proportional-integral-derivative (PID) control algorithm to converge the contrast to the target range. The control system records the brightness change for each adjustment as the brightness adjustment amount and continuously monitors and adjusts it. This embodiment eliminates the need for an additional ambient light sensor and can automatically compensate for reflectivity changes caused by differences in skin color and surface material of the target object, ensuring clear projection effects for different patients.

[0106] like Figure 3 As shown, according to another aspect of the embodiments of this application, an in-ring light field projection device is also provided, including: a first acquisition unit, a second acquisition unit, and a processing unit. The first acquisition unit is used to acquire three-dimensional spatial data of a target object; the second acquisition unit is used to acquire position data of a ray source and ray field data; the processing unit is used to determine projection control data based on the three-dimensional spatial data of the target object, the position data of the ray source, and the ray field data, and send the projection control data to a projection module. The ray source is disposed within the inner cavity of the annular frame, and the projection module is disposed in the outer space of the annular frame. The projection module projects visible light onto the surface of the target object according to the projection control data, and the area where the visible light is located coincides with the ray irradiation field generated by the ray source.

[0107] Optionally, the first acquisition unit includes: a first acquisition subunit, used to acquire image data of the surface of a target object; a stereo matching subunit, used to perform stereo matching of the target object based on the image data of the surface of the target object to determine the three-dimensional point cloud data of the target object, wherein the three-dimensional point cloud data includes multiple points with three-dimensional coordinates; and a data generation subunit, used to determine the three-dimensional spatial data of the target object based on the three-dimensional point cloud data, wherein the three-dimensional spatial data characterizes the geometric shape of the surface of the target object.

[0108] Optionally, the processing unit includes: a coordinate transformation subunit for transforming the position data of the ray source, the position data of the projection module, and the three-dimensional spatial data into a unified spatial coordinate system; a spatial range determination subunit for determining the spatial range of the ray beam based on the position data of the ray source and the radiation field data, wherein the radiation field data includes radiation field shape parameters and radiation field size parameters, and the spatial range of the ray beam is used to determine the intersection line between the ray beam and the surface of the target object; a contour determination subunit for determining the contour data of the visible light region on the surface of the target object based on the spatial range of the ray beam; and a projection path determination subunit for calculating the visible light projection path and determining the projection control data based on the contour data and the position data of the projection module through inverse coordinate transformation.

[0109] Optionally, the contour determination subunit includes: a starting point determination module, used to determine the starting point of the ray beam based on the position data of the ray source; an edge direction determination module, used to determine the edge ray direction of the ray beam based on the radiation field data; an edge ray generation module, used to determine multiple edge rays based on the starting point and the edge ray direction, wherein each edge ray is used to define the outer boundary of the ray beam; an intersection point calculation module, used to calculate the intersection points of each edge ray with the surface of the target object; and a contour generation module, used to determine the contour data of the visible light region on the surface of the target object based on each intersection point, wherein the contour data characterizes the boundary position of the visible light region.

[0110] Optionally, the projection path determination subunit includes: a position acquisition module for acquiring position data of the projection module in a unified spatial coordinate system; a coordinate transformation module for transforming the contour data from the unified spatial coordinate system to the local coordinate system of the projection module, and determining the transformed contour data, wherein the local coordinate system is established with the projection module as the origin; a trajectory determination module for determining the scanning trajectory of the visible beam based on the transformed contour data, wherein the scanning trajectory includes the position coordinates and scanning order of multiple scanning points; and a control data generation module for determining projection control data based on the scanning trajectory of the visible beam.

[0111] Optionally, the projection module is a laser projection module, which includes a laser emitter and a laser scanning mechanism. The module sends projection control data to the projection module, including: a first transmitting subunit for sending projection control data to the laser emitter, wherein the laser emitter generates a laser beam; and a second transmitting subunit for sending projection control data to the laser scanning mechanism, wherein the laser scanning mechanism adjusts the projection direction of the laser beam so that the laser beam scans the area on the surface of the target object to form visible light.

[0112] Optionally, the processing unit further includes: an adjustment instruction sending subunit, used to send an adjustment instruction to the adjustable structure before sending the projection control data to the projection module, wherein the adjustment instruction is used to instruct the adjustable structure to adjust the spatial position and projection angle of the projection module, the spatial position including translation along a first direction, a second direction and a third direction that are perpendicular to each other, and the projection angle including a rotation angle around the first direction, the second direction and the third direction.

[0113] Optionally, the in-ring optical field projection system further includes: a third acquisition unit for acquiring three-dimensional spatial data of the calibration phantom, wherein the calibration phantom is placed at an isocenter point, the isocenter point representing the intersection of the beam central axis of the X-ray source and the rotation axis of the annular frame; a projection control unit for controlling the projection module to project a calibration pattern onto the calibration phantom, wherein the calibration pattern is a visible light pattern with a preset geometry; a calibration parameter generation unit for generating calibration parameters based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom, wherein the deviation represents the difference between the actual projection direction of the projection module and the standard projection direction; and a storage unit for storing the calibration parameters, wherein the calibration parameters are used to correct the projection control data.

[0114] Optionally, the calibration parameter generation unit includes: an offset calculation subunit, used to calculate the spatial offset and attitude deviation angle between the projection module and the isocenter point based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom, wherein the spatial offset characterizes the positional difference between the projection origin of the projection module and the isocenter point in three-dimensional space, and the attitude deviation angle characterizes the angular difference between the actual projection direction of the projection module and the ideal projection direction pointing to the isocenter point; and a matrix determination subunit, used to determine the calibration mapping matrix based on the spatial offset and the attitude deviation angle, and use the calibration mapping matrix as calibration parameters, wherein the calibration mapping matrix is ​​used to transform the projection control data from the local coordinate system of the projection module to the coordinate system of the isocenter point.

[0115] Optionally, the in-ring light field projection system further includes: a dynamic acquisition unit, used to acquire dynamic three-dimensional spatial data of the surface of the target object during the projection of visible light by the projection module, wherein the dynamic three-dimensional spatial data characterizes the surface morphological changes of the target object caused by breathing, heartbeat or body position movement; and an update unit, used to update the projection control data according to the dynamic three-dimensional spatial data, wherein the updated projection control data is used to make the area where the visible light is located follow the morphological changes of the target object's surface.

[0116] Optionally, the dynamic acquisition unit includes a respiratory gating acquisition subunit, used to acquire dynamic three-dimensional spatial data at a specific phase of the respiratory cycle of the target object according to the respiratory gating signal. The respiratory gating signal is used to identify a specific phase interval between the end-inspiratory phase, the end-expiratory phase, or the end-inspiratory phase and the end-expiratory phase in the respiratory cycle of the target object. The specific phase is the phase in which the surface motion amplitude of the target object is minimal.

[0117] Optionally, the in-ring light field projection system further includes: a brightness detection unit for detecting the illumination brightness of the environment in which the projection module is located, wherein the illumination brightness characterizes the light intensity of the environment surrounding the projection module; a brightness adjustment amount determination unit for determining the brightness adjustment amount based on the detected illumination brightness, wherein the brightness adjustment amount characterizes the range by which the light output intensity of the projection module needs to be adjusted, and the brightness adjustment amount is positively or negatively correlated with the illumination brightness; and a light output intensity adjustment unit for adjusting the light output intensity of the projection module based on the brightness adjustment amount, wherein the light output intensity characterizes the light power density of the visible light emitted by the projection module.

[0118] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, which stores a computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located performs the above-described in-ring light field projection method.

[0119] According to another aspect of the embodiments of this application, an electronic device is also provided, including one or more processors and a memory, the memory being used to store one or more programs, wherein when one or more programs are executed by one or more processors, the one or more processors cause the one or more processors to perform the above-described in-ring light field projection method.

[0120] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program or instructions that, when executed by a processor, implement the above-described method for projection of the inner ring light field.

[0121] The sequence numbers of the embodiments described above are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. In the above embodiments of this application, the descriptions of each embodiment have their own emphasis; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. It should be understood that the disclosed technical content in the several embodiments provided in this application can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units can be a logical functional division, and in actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Furthermore, the displayed or discussed mutual coupling or direct coupling or communication connection can be through some interfaces; the indirect coupling or communication connection between units or modules can be electrical or other forms. The units described as separate components may or may not be physically separated; the components shown as units may or may not be physical units, that is, they can be located in one place or distributed across multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution in this embodiment.

[0122] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes: USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, optical disks, and other media capable of storing program code.

[0123] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for projecting an inner-ring optical field, characterized in that, include: Obtain the three-dimensional spatial data of the target object; Acquire the location data of the radiation source and the radiation field data; Based on the three-dimensional spatial data of the target object, the position data of the ray source, and the irradiation field data, projection control data is determined and sent to the projection module. The ray source is located in the inner cavity of the ring frame, and the projection module is located in the outer space of the ring frame. The projection module projects visible light onto the surface of the target object according to the projection control data, and the area where the visible light is located is consistent with the ray irradiation field generated by the ray source. The method further includes: during the projection of visible light by the projection module, acquiring dynamic three-dimensional spatial data of the surface of the target object, wherein the dynamic three-dimensional spatial data characterizes the surface morphological changes of the target object caused by breathing, heartbeat, or body position movement; and updating the projection control data according to the dynamic three-dimensional spatial data, wherein the updated projection control data is used to make the area where the visible light is located follow the morphological changes of the target object's surface.

2. The method according to claim 1, characterized in that, Obtain the three-dimensional spatial data of the target object, including: Acquire image data of the surface of the target object; Based on the image data of the target object's surface, stereo matching of the target object is performed to determine the three-dimensional point cloud data of the target object, wherein the three-dimensional point cloud data includes multiple points with three-dimensional coordinates; Based on the three-dimensional point cloud data, the three-dimensional spatial data of the target object is determined, wherein the three-dimensional spatial data characterizes the geometric shape of the surface of the target object.

3. The method according to claim 1, characterized in that, Based on the three-dimensional spatial data of the target object, the position data of the ray source, and the ray field data, projection control data is determined, including: The position data of the ray source, the position data of the projection module, and the three-dimensional spatial data are converted to a unified spatial coordinate system. Based on the location data of the radiation source and the radiation field data, the spatial range of the radiation beam is determined, wherein the radiation field data includes radiation field shape parameters and radiation field size parameters, and the spatial range of the radiation beam is used to determine the intersection line between the radiation beam and the surface of the target object; Based on the spatial range of the ray beam, determine the contour data of the visible light region on the surface of the target object; Based on the contour data and the position data of the projection module, the visible light projection path is calculated through inverse coordinate transformation, and the projection control data is determined.

4. The method according to claim 3, characterized in that, Based on the spatial range of the ray beam, the contour data of the visible light region on the surface of the target object is determined, including: Based on the location data of the radiation source, determine the starting point of the radiation beam; Based on the radiation field data, determine the edge ray direction of the radiation beam; Based on the starting point and the direction of the edge rays, multiple edge rays are determined, wherein each edge ray is used to define the outer boundary of the ray beam; Calculate the intersection points of each edge ray with the surface of the target object; Based on each of the intersection points, the contour data of the visible light region on the surface of the target object is determined, wherein the contour data characterizes the boundary position of the visible light region.

5. The method according to claim 3, characterized in that, Based on the contour data and the position data of the projection module, the visible light projection path is calculated through inverse coordinate transformation, and the projection control data is determined, including: Obtain the position data of the projection module in the unified spatial coordinate system; The contour data is transformed from the unified spatial coordinate system to the local coordinate system of the projection module to determine the transformed contour data, wherein the local coordinate system is established with the projection module as the origin; Based on the converted contour data, the scanning trajectory of the visible light beam is determined, wherein the scanning trajectory includes the position coordinates of multiple scanning points and the scanning order; Projection control data is determined based on the scanning trajectory of the visible light beam.

6. The method according to claim 1, characterized in that, The projection module is a laser projection module, which includes a laser emitter and a laser scanning mechanism. The projection control data is sent to the projection module, including: The projection control data is sent to the laser emitter, wherein the laser emitter is used to generate a laser beam; The projection control data is sent to the laser scanning mechanism, which is used to adjust the projection direction of the laser beam so that the laser beam scans the area on the surface of the target object where the visible light is formed.

7. The method according to claim 1, characterized in that, The method further includes: Before sending the projection control data to the projection module, an adjustment command is sent to the adjustable structure, wherein the adjustment command is used to instruct the adjustable structure to adjust the spatial position and projection angle of the projection module, the spatial position including translation along a first direction, a second direction and a third direction that are perpendicular to each other, and the projection angle including rotation angles around the first direction, the second direction and the third direction.

8. The method according to claim 1, characterized in that, The method further includes: Acquire three-dimensional spatial data of the calibration phantom, wherein the calibration phantom is placed at an isocenter point, the isocenter point representing the intersection of the beam center axis of the X-ray source and the rotation axis of the annular frame; The projection module is controlled to project a calibration pattern onto the calibration phantom, wherein the calibration pattern is a visible light pattern with a preset geometric shape; Based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom, calibration parameters are generated, wherein the deviation characterizes the difference between the actual projection direction of the projection module and the standard projection direction; The calibration parameters are stored, wherein the calibration parameters are used to correct the projection control data.

9. The method according to claim 8, characterized in that, Based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom, calibration parameters are generated, including: Based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom, the spatial offset and attitude deviation angle between the projection module and the isocenter point are calculated. The spatial offset represents the positional difference between the projection origin of the projection module and the isocenter point in three-dimensional space, and the attitude deviation angle represents the angular difference between the actual projection direction of the projection module and the ideal projection direction pointing to the isocenter point. Based on the spatial offset and the attitude deviation angle, a calibration mapping matrix is ​​determined, and the calibration mapping matrix is ​​used as the calibration parameter. The calibration mapping matrix is ​​used to transform the projection control data from the local coordinate system of the projection module to the isocentric point coordinate system.

10. The method according to claim 1, characterized in that, Acquiring dynamic three-dimensional spatial data of the surface of the target object includes: According to the respiratory gating signal, the dynamic three-dimensional spatial data is acquired at a specific phase of the respiratory cycle of the target object. The respiratory gating signal is used to identify a specific phase interval between the end-inspiratory phase, the end-expiratory phase, or the end-inspiratory phase and the end-expiratory phase in the respiratory cycle of the target object. The specific phase is the phase in which the surface motion amplitude of the target object is minimal.

11. The method according to claim 1, characterized in that, The method further includes: The illumination brightness of the environment in which the projection module is located is detected, wherein the illumination brightness characterizes the light intensity of the environment surrounding the projection module; Based on the detected illumination brightness, a brightness adjustment amount is determined, wherein the brightness adjustment amount characterizes the extent to which the light intensity emitted by the projection module needs to be adjusted, and the brightness adjustment amount is positively or negatively correlated with the illumination brightness; The light intensity emitted by the projection module is adjusted according to the brightness adjustment amount, wherein the light intensity represents the light power density of the visible light emitted by the projection module.

12. A projection device for an inner-ring light field, characterized in that, include: The first acquisition unit is used to acquire the three-dimensional spatial data of the target object; The second acquisition unit is used to acquire the location data of the radiation source and the radiation field data; The processing unit is used to determine projection control data based on the three-dimensional spatial data of the target object, the position data of the ray source, and the irradiation field data, and send the projection control data to the projection module. The ray source is set in the inner cavity of the ring frame, and the projection module is set in the outer space of the ring frame. The projection module projects visible light onto the surface of the target object according to the projection control data, and the area where the visible light is located is consistent with the ray irradiation field generated by the ray source. The dynamic acquisition unit is used to acquire dynamic three-dimensional spatial data of the surface of the target object during the process of the projection module projecting visible light, wherein the dynamic three-dimensional spatial data characterizes the surface morphological changes of the target object caused by breathing, heartbeat or body position movement. An update unit is used to update the projection control data based on the dynamic three-dimensional spatial data, wherein the updated projection control data is used to make the area where the visible light is located follow the shape change of the target object surface.

13. The apparatus according to claim 12, characterized in that, The first acquisition unit includes: The first acquisition subunit is used to acquire image data of the surface of the target object; A stereo matching subunit is used to perform stereo matching of the target object based on the image data of the target object surface to determine the three-dimensional point cloud data of the target object, wherein the three-dimensional point cloud data includes multiple points with three-dimensional coordinates; A data generation subunit is used to determine the three-dimensional spatial data of the target object based on the three-dimensional point cloud data, wherein the three-dimensional spatial data characterizes the geometric shape of the surface of the target object.

14. The apparatus according to claim 12, characterized in that, The processing unit includes: The coordinate transformation subunit is used to transform the position data of the ray source, the position data of the projection module, and the three-dimensional spatial data into a unified spatial coordinate system. The spatial range determination subunit is used to determine the spatial range of the ray beam based on the position data of the ray source and the ray field data, wherein the ray field data includes ray field shape parameters and ray field size parameters, and the spatial range of the ray beam is used to determine the intersection line between the ray beam and the surface of the target object; The contour determination subunit is used to determine the contour data of the visible light region on the surface of the target object based on the spatial range of the ray beam. The projection path determination subunit is used to calculate the visible light projection path and determine the projection control data based on the contour data and the position data of the projection module by reverse coordinate transformation.

15. The apparatus according to claim 14, characterized in that, The contour-determining subunit includes: The starting point determination module is used to determine the starting point of the ray beam based on the position data of the ray source; An edge direction determination module is used to determine the edge ray direction of the ray beam based on the ray field data. An edge ray generation module is used to determine multiple edge rays based on the starting point and the edge ray direction, wherein each edge ray is used to define the outer boundary of the ray beam; The intersection point calculation module is used to calculate the intersection points of each of the edge rays with the surface of the target object; A contour generation module is used to determine the contour data of the visible light region on the surface of the target object based on each of the intersection points, wherein the contour data represents the boundary position of the visible light region.

16. The apparatus according to claim 14, characterized in that, The projection path determination subunit includes: A position acquisition module is used to acquire the position data of the projection module in the unified spatial coordinate system; The coordinate transformation module is used to transform the contour data from the unified spatial coordinate system to the local coordinate system of the projection module, and to determine the transformed contour data, wherein the local coordinate system is established with the projection module as the origin; The trajectory determination module is used to determine the scanning trajectory of the visible light beam based on the converted contour data, wherein the scanning trajectory includes the position coordinates of multiple scanning points and the scanning order; The control data generation module is used to determine projection control data based on the scanning trajectory of the visible light beam.

17. The apparatus according to claim 12, characterized in that, The projection module is a laser projection module, which includes a laser emitter and a laser scanning mechanism. The projection control data is sent to the projection module, including: A first transmitting subunit is configured to transmit the projection control data to the laser emitter, wherein the laser emitter is configured to generate a laser beam; The second transmitting subunit is used to send the projection control data to the laser scanning mechanism, wherein the laser scanning mechanism is used to adjust the projection direction of the laser beam so that the laser beam scans the area on the surface of the target object where the visible light is formed.

18. The apparatus according to claim 12, characterized in that, The processing unit further includes: An adjustment command sending subunit is used to send an adjustment command to the adjustable structure before sending the projection control data to the projection module. The adjustment command is used to instruct the adjustable structure to adjust the spatial position and projection angle of the projection module. The spatial position includes a translation along a first direction, a second direction, and a third direction that are perpendicular to each other. The projection angle includes a rotation angle around the first direction, the second direction, and the third direction.

19. The apparatus according to claim 12, characterized in that, The device further includes: The third acquisition unit is used to acquire the three-dimensional spatial data of the calibration phantom, wherein the calibration phantom is placed at an isocenter point, and the isocenter point represents the intersection of the beam center axis of the X-ray source and the rotation axis of the annular frame. A projection control unit is used to control the projection module to project a calibration pattern onto the calibration model, wherein the calibration pattern is a visible light pattern with a preset geometric shape; The calibration parameter generation unit is used to generate calibration parameters based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom, wherein the deviation characterizes the difference between the actual projection direction of the projection module and the standard projection direction; A storage unit is provided for storing the calibration parameters, wherein the calibration parameters are used to correct the projection control data.

20. The apparatus according to claim 19, characterized in that, The calibration parameter generation unit includes: The offset calculation subunit is used to calculate the spatial offset and attitude deviation angle between the projection module and the isocenter point based on the deviation between the three-dimensional spatial data of the calibration phantom and the imaging position of the calibration pattern on the calibration phantom. The spatial offset represents the positional difference between the projection origin of the projection module and the isocenter point in three-dimensional space, and the attitude deviation angle represents the angular difference between the actual projection direction of the projection module and the ideal projection direction pointing to the isocenter point. The matrix determination subunit is used to determine the calibration mapping matrix based on the spatial offset and the attitude deviation angle, and to use the calibration mapping matrix as the calibration parameter. The calibration mapping matrix is ​​used to transform the projection control data from the local coordinate system of the projection module to the isocenter point coordinate system.

21. The apparatus according to claim 12, characterized in that, The dynamic acquisition unit includes: The respiratory gating acquisition subunit is used to acquire the dynamic three-dimensional spatial data at a specific phase of the respiratory cycle of the target object according to the respiratory gating signal. The respiratory gating signal is used to identify a specific phase interval between the end-inspiratory phase, the end-expiratory phase, or the end-inspiratory phase and the end-expiratory phase in the respiratory cycle of the target object. The specific phase is the phase in which the surface motion amplitude of the target object is minimal.

22. The apparatus according to claim 12, characterized in that, The device further includes: A brightness detection unit is used to detect the lighting brightness of the environment in which the projection module is located, wherein the lighting brightness characterizes the light intensity of the environment around the projection module; A brightness adjustment amount determination unit is used to determine a brightness adjustment amount based on the detected illumination brightness, wherein the brightness adjustment amount characterizes the range by which the light intensity emitted by the projection module needs to be adjusted, and the brightness adjustment amount is positively or negatively correlated with the illumination brightness; The light intensity adjustment unit is used to adjust the light intensity of the projection module according to the brightness adjustment amount, wherein the light intensity represents the light power density of the visible light emitted by the projection module.

23. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein when the computer program is executed, the device containing the computer-readable storage medium performs the in-ring light field projection method according to any one of claims 1 to 11.

24. An electronic device, characterized in that, It includes one or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to perform the in-ring light field projection method according to any one of claims 1 to 11.

25. A computer program product, characterized in that, It includes a computer program or instructions that, when executed by a processor, implement the in-ring optical field projection method according to any one of claims 1 to 11.

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